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6451 lines
180 KiB
6451 lines
180 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (c) 2003-2006, Cluster File Systems, Inc, [email protected] |
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* Written by Alex Tomas <[email protected]> |
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*/ |
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|
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/* |
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* mballoc.c contains the multiblocks allocation routines |
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*/ |
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|
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#include "ext4_jbd2.h" |
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#include "mballoc.h" |
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#include <linux/log2.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/nospec.h> |
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#include <linux/backing-dev.h> |
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#include <trace/events/ext4.h> |
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|
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/* |
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* MUSTDO: |
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* - test ext4_ext_search_left() and ext4_ext_search_right() |
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* - search for metadata in few groups |
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* |
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* TODO v4: |
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* - normalization should take into account whether file is still open |
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* - discard preallocations if no free space left (policy?) |
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* - don't normalize tails |
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* - quota |
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* - reservation for superuser |
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* |
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* TODO v3: |
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* - bitmap read-ahead (proposed by Oleg Drokin aka green) |
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* - track min/max extents in each group for better group selection |
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* - mb_mark_used() may allocate chunk right after splitting buddy |
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* - tree of groups sorted by number of free blocks |
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* - error handling |
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*/ |
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|
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/* |
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* The allocation request involve request for multiple number of blocks |
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* near to the goal(block) value specified. |
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* |
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* During initialization phase of the allocator we decide to use the |
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* group preallocation or inode preallocation depending on the size of |
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* the file. The size of the file could be the resulting file size we |
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* would have after allocation, or the current file size, which ever |
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* is larger. If the size is less than sbi->s_mb_stream_request we |
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* select to use the group preallocation. The default value of |
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* s_mb_stream_request is 16 blocks. This can also be tuned via |
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* /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in |
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* terms of number of blocks. |
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* |
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* The main motivation for having small file use group preallocation is to |
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* ensure that we have small files closer together on the disk. |
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* |
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* First stage the allocator looks at the inode prealloc list, |
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* ext4_inode_info->i_prealloc_list, which contains list of prealloc |
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* spaces for this particular inode. The inode prealloc space is |
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* represented as: |
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* |
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* pa_lstart -> the logical start block for this prealloc space |
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* pa_pstart -> the physical start block for this prealloc space |
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* pa_len -> length for this prealloc space (in clusters) |
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* pa_free -> free space available in this prealloc space (in clusters) |
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* |
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* The inode preallocation space is used looking at the _logical_ start |
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* block. If only the logical file block falls within the range of prealloc |
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* space we will consume the particular prealloc space. This makes sure that |
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* we have contiguous physical blocks representing the file blocks |
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* |
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* The important thing to be noted in case of inode prealloc space is that |
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* we don't modify the values associated to inode prealloc space except |
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* pa_free. |
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* |
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* If we are not able to find blocks in the inode prealloc space and if we |
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* have the group allocation flag set then we look at the locality group |
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* prealloc space. These are per CPU prealloc list represented as |
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* |
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* ext4_sb_info.s_locality_groups[smp_processor_id()] |
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* |
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* The reason for having a per cpu locality group is to reduce the contention |
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* between CPUs. It is possible to get scheduled at this point. |
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* |
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* The locality group prealloc space is used looking at whether we have |
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* enough free space (pa_free) within the prealloc space. |
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* |
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* If we can't allocate blocks via inode prealloc or/and locality group |
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* prealloc then we look at the buddy cache. The buddy cache is represented |
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* by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets |
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* mapped to the buddy and bitmap information regarding different |
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* groups. The buddy information is attached to buddy cache inode so that |
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* we can access them through the page cache. The information regarding |
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* each group is loaded via ext4_mb_load_buddy. The information involve |
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* block bitmap and buddy information. The information are stored in the |
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* inode as: |
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* |
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* { page } |
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* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... |
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* |
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* |
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* one block each for bitmap and buddy information. So for each group we |
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* take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE / |
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* blocksize) blocks. So it can have information regarding groups_per_page |
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* which is blocks_per_page/2 |
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* |
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* The buddy cache inode is not stored on disk. The inode is thrown |
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* away when the filesystem is unmounted. |
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* |
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* We look for count number of blocks in the buddy cache. If we were able |
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* to locate that many free blocks we return with additional information |
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* regarding rest of the contiguous physical block available |
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* |
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* Before allocating blocks via buddy cache we normalize the request |
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* blocks. This ensure we ask for more blocks that we needed. The extra |
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* blocks that we get after allocation is added to the respective prealloc |
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* list. In case of inode preallocation we follow a list of heuristics |
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* based on file size. This can be found in ext4_mb_normalize_request. If |
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* we are doing a group prealloc we try to normalize the request to |
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* sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is |
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* dependent on the cluster size; for non-bigalloc file systems, it is |
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* 512 blocks. This can be tuned via |
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* /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in |
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* terms of number of blocks. If we have mounted the file system with -O |
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* stripe=<value> option the group prealloc request is normalized to the |
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* smallest multiple of the stripe value (sbi->s_stripe) which is |
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* greater than the default mb_group_prealloc. |
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* |
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* If "mb_optimize_scan" mount option is set, we maintain in memory group info |
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* structures in two data structures: |
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* |
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* 1) Array of largest free order lists (sbi->s_mb_largest_free_orders) |
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* |
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* Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks) |
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* |
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* This is an array of lists where the index in the array represents the |
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* largest free order in the buddy bitmap of the participating group infos of |
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* that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total |
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* number of buddy bitmap orders possible) number of lists. Group-infos are |
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* placed in appropriate lists. |
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* |
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* 2) Average fragment size rb tree (sbi->s_mb_avg_fragment_size_root) |
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* |
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* Locking: sbi->s_mb_rb_lock (rwlock) |
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* |
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* This is a red black tree consisting of group infos and the tree is sorted |
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* by average fragment sizes (which is calculated as ext4_group_info->bb_free |
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* / ext4_group_info->bb_fragments). |
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* |
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* When "mb_optimize_scan" mount option is set, mballoc consults the above data |
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* structures to decide the order in which groups are to be traversed for |
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* fulfilling an allocation request. |
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* |
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* At CR = 0, we look for groups which have the largest_free_order >= the order |
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* of the request. We directly look at the largest free order list in the data |
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* structure (1) above where largest_free_order = order of the request. If that |
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* list is empty, we look at remaining list in the increasing order of |
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* largest_free_order. This allows us to perform CR = 0 lookup in O(1) time. |
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* |
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* At CR = 1, we only consider groups where average fragment size > request |
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* size. So, we lookup a group which has average fragment size just above or |
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* equal to request size using our rb tree (data structure 2) in O(log N) time. |
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* |
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* If "mb_optimize_scan" mount option is not set, mballoc traverses groups in |
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* linear order which requires O(N) search time for each CR 0 and CR 1 phase. |
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* |
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* The regular allocator (using the buddy cache) supports a few tunables. |
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* |
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* /sys/fs/ext4/<partition>/mb_min_to_scan |
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* /sys/fs/ext4/<partition>/mb_max_to_scan |
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* /sys/fs/ext4/<partition>/mb_order2_req |
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* /sys/fs/ext4/<partition>/mb_linear_limit |
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* |
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* The regular allocator uses buddy scan only if the request len is power of |
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* 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The |
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* value of s_mb_order2_reqs can be tuned via |
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* /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to |
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* stripe size (sbi->s_stripe), we try to search for contiguous block in |
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* stripe size. This should result in better allocation on RAID setups. If |
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* not, we search in the specific group using bitmap for best extents. The |
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* tunable min_to_scan and max_to_scan control the behaviour here. |
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* min_to_scan indicate how long the mballoc __must__ look for a best |
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* extent and max_to_scan indicates how long the mballoc __can__ look for a |
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* best extent in the found extents. Searching for the blocks starts with |
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* the group specified as the goal value in allocation context via |
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* ac_g_ex. Each group is first checked based on the criteria whether it |
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* can be used for allocation. ext4_mb_good_group explains how the groups are |
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* checked. |
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* |
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* When "mb_optimize_scan" is turned on, as mentioned above, the groups may not |
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* get traversed linearly. That may result in subsequent allocations being not |
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* close to each other. And so, the underlying device may get filled up in a |
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* non-linear fashion. While that may not matter on non-rotational devices, for |
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* rotational devices that may result in higher seek times. "mb_linear_limit" |
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* tells mballoc how many groups mballoc should search linearly before |
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* performing consulting above data structures for more efficient lookups. For |
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* non rotational devices, this value defaults to 0 and for rotational devices |
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* this is set to MB_DEFAULT_LINEAR_LIMIT. |
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* |
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* Both the prealloc space are getting populated as above. So for the first |
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* request we will hit the buddy cache which will result in this prealloc |
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* space getting filled. The prealloc space is then later used for the |
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* subsequent request. |
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*/ |
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/* |
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* mballoc operates on the following data: |
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* - on-disk bitmap |
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* - in-core buddy (actually includes buddy and bitmap) |
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* - preallocation descriptors (PAs) |
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* |
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* there are two types of preallocations: |
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* - inode |
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* assiged to specific inode and can be used for this inode only. |
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* it describes part of inode's space preallocated to specific |
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* physical blocks. any block from that preallocated can be used |
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* independent. the descriptor just tracks number of blocks left |
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* unused. so, before taking some block from descriptor, one must |
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* make sure corresponded logical block isn't allocated yet. this |
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* also means that freeing any block within descriptor's range |
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* must discard all preallocated blocks. |
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* - locality group |
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* assigned to specific locality group which does not translate to |
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* permanent set of inodes: inode can join and leave group. space |
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* from this type of preallocation can be used for any inode. thus |
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* it's consumed from the beginning to the end. |
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* |
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* relation between them can be expressed as: |
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* in-core buddy = on-disk bitmap + preallocation descriptors |
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* |
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* this mean blocks mballoc considers used are: |
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* - allocated blocks (persistent) |
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* - preallocated blocks (non-persistent) |
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* |
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* consistency in mballoc world means that at any time a block is either |
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* free or used in ALL structures. notice: "any time" should not be read |
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* literally -- time is discrete and delimited by locks. |
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* |
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* to keep it simple, we don't use block numbers, instead we count number of |
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* blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. |
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* |
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* all operations can be expressed as: |
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* - init buddy: buddy = on-disk + PAs |
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* - new PA: buddy += N; PA = N |
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* - use inode PA: on-disk += N; PA -= N |
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* - discard inode PA buddy -= on-disk - PA; PA = 0 |
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* - use locality group PA on-disk += N; PA -= N |
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* - discard locality group PA buddy -= PA; PA = 0 |
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* note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap |
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* is used in real operation because we can't know actual used |
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* bits from PA, only from on-disk bitmap |
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* |
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* if we follow this strict logic, then all operations above should be atomic. |
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* given some of them can block, we'd have to use something like semaphores |
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* killing performance on high-end SMP hardware. let's try to relax it using |
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* the following knowledge: |
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* 1) if buddy is referenced, it's already initialized |
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* 2) while block is used in buddy and the buddy is referenced, |
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* nobody can re-allocate that block |
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* 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has |
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* bit set and PA claims same block, it's OK. IOW, one can set bit in |
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* on-disk bitmap if buddy has same bit set or/and PA covers corresponded |
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* block |
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* |
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* so, now we're building a concurrency table: |
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* - init buddy vs. |
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* - new PA |
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* blocks for PA are allocated in the buddy, buddy must be referenced |
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* until PA is linked to allocation group to avoid concurrent buddy init |
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* - use inode PA |
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* we need to make sure that either on-disk bitmap or PA has uptodate data |
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* given (3) we care that PA-=N operation doesn't interfere with init |
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* - discard inode PA |
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* the simplest way would be to have buddy initialized by the discard |
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* - use locality group PA |
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* again PA-=N must be serialized with init |
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* - discard locality group PA |
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* the simplest way would be to have buddy initialized by the discard |
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* - new PA vs. |
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* - use inode PA |
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* i_data_sem serializes them |
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* - discard inode PA |
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* discard process must wait until PA isn't used by another process |
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* - use locality group PA |
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* some mutex should serialize them |
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* - discard locality group PA |
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* discard process must wait until PA isn't used by another process |
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* - use inode PA |
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* - use inode PA |
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* i_data_sem or another mutex should serializes them |
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* - discard inode PA |
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* discard process must wait until PA isn't used by another process |
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* - use locality group PA |
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* nothing wrong here -- they're different PAs covering different blocks |
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* - discard locality group PA |
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* discard process must wait until PA isn't used by another process |
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* |
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* now we're ready to make few consequences: |
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* - PA is referenced and while it is no discard is possible |
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* - PA is referenced until block isn't marked in on-disk bitmap |
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* - PA changes only after on-disk bitmap |
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* - discard must not compete with init. either init is done before |
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* any discard or they're serialized somehow |
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* - buddy init as sum of on-disk bitmap and PAs is done atomically |
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* |
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* a special case when we've used PA to emptiness. no need to modify buddy |
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* in this case, but we should care about concurrent init |
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* |
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*/ |
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/* |
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* Logic in few words: |
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* |
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* - allocation: |
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* load group |
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* find blocks |
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* mark bits in on-disk bitmap |
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* release group |
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* |
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* - use preallocation: |
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* find proper PA (per-inode or group) |
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* load group |
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* mark bits in on-disk bitmap |
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* release group |
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* release PA |
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* |
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* - free: |
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* load group |
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* mark bits in on-disk bitmap |
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* release group |
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* |
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* - discard preallocations in group: |
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* mark PAs deleted |
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* move them onto local list |
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* load on-disk bitmap |
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* load group |
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* remove PA from object (inode or locality group) |
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* mark free blocks in-core |
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* |
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* - discard inode's preallocations: |
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*/ |
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/* |
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* Locking rules |
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* |
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* Locks: |
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* - bitlock on a group (group) |
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* - object (inode/locality) (object) |
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* - per-pa lock (pa) |
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* - cr0 lists lock (cr0) |
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* - cr1 tree lock (cr1) |
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* |
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* Paths: |
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* - new pa |
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* object |
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* group |
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* |
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* - find and use pa: |
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* pa |
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* |
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* - release consumed pa: |
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* pa |
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* group |
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* object |
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* |
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* - generate in-core bitmap: |
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* group |
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* pa |
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* |
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* - discard all for given object (inode, locality group): |
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* object |
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* pa |
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* group |
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* |
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* - discard all for given group: |
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* group |
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* pa |
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* group |
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* object |
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* |
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* - allocation path (ext4_mb_regular_allocator) |
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* group |
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* cr0/cr1 |
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*/ |
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static struct kmem_cache *ext4_pspace_cachep; |
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static struct kmem_cache *ext4_ac_cachep; |
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static struct kmem_cache *ext4_free_data_cachep; |
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|
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/* We create slab caches for groupinfo data structures based on the |
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* superblock block size. There will be one per mounted filesystem for |
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* each unique s_blocksize_bits */ |
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#define NR_GRPINFO_CACHES 8 |
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static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES]; |
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static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = { |
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"ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k", |
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"ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k", |
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"ext4_groupinfo_64k", "ext4_groupinfo_128k" |
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}; |
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static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
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ext4_group_t group); |
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static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, |
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ext4_group_t group); |
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static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac); |
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|
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static bool ext4_mb_good_group(struct ext4_allocation_context *ac, |
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ext4_group_t group, int cr); |
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|
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/* |
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* The algorithm using this percpu seq counter goes below: |
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* 1. We sample the percpu discard_pa_seq counter before trying for block |
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* allocation in ext4_mb_new_blocks(). |
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* 2. We increment this percpu discard_pa_seq counter when we either allocate |
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* or free these blocks i.e. while marking those blocks as used/free in |
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* mb_mark_used()/mb_free_blocks(). |
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* 3. We also increment this percpu seq counter when we successfully identify |
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* that the bb_prealloc_list is not empty and hence proceed for discarding |
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* of those PAs inside ext4_mb_discard_group_preallocations(). |
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* |
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* Now to make sure that the regular fast path of block allocation is not |
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* affected, as a small optimization we only sample the percpu seq counter |
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* on that cpu. Only when the block allocation fails and when freed blocks |
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* found were 0, that is when we sample percpu seq counter for all cpus using |
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* below function ext4_get_discard_pa_seq_sum(). This happens after making |
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* sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty. |
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*/ |
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static DEFINE_PER_CPU(u64, discard_pa_seq); |
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static inline u64 ext4_get_discard_pa_seq_sum(void) |
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{ |
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int __cpu; |
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u64 __seq = 0; |
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|
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for_each_possible_cpu(__cpu) |
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__seq += per_cpu(discard_pa_seq, __cpu); |
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return __seq; |
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} |
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|
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static inline void *mb_correct_addr_and_bit(int *bit, void *addr) |
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{ |
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#if BITS_PER_LONG == 64 |
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*bit += ((unsigned long) addr & 7UL) << 3; |
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addr = (void *) ((unsigned long) addr & ~7UL); |
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#elif BITS_PER_LONG == 32 |
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*bit += ((unsigned long) addr & 3UL) << 3; |
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addr = (void *) ((unsigned long) addr & ~3UL); |
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#else |
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#error "how many bits you are?!" |
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#endif |
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return addr; |
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} |
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|
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static inline int mb_test_bit(int bit, void *addr) |
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{ |
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/* |
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* ext4_test_bit on architecture like powerpc |
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* needs unsigned long aligned address |
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*/ |
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addr = mb_correct_addr_and_bit(&bit, addr); |
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return ext4_test_bit(bit, addr); |
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} |
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|
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static inline void mb_set_bit(int bit, void *addr) |
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{ |
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addr = mb_correct_addr_and_bit(&bit, addr); |
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ext4_set_bit(bit, addr); |
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} |
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|
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static inline void mb_clear_bit(int bit, void *addr) |
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{ |
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addr = mb_correct_addr_and_bit(&bit, addr); |
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ext4_clear_bit(bit, addr); |
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} |
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|
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static inline int mb_test_and_clear_bit(int bit, void *addr) |
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{ |
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addr = mb_correct_addr_and_bit(&bit, addr); |
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return ext4_test_and_clear_bit(bit, addr); |
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} |
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|
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static inline int mb_find_next_zero_bit(void *addr, int max, int start) |
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{ |
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int fix = 0, ret, tmpmax; |
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addr = mb_correct_addr_and_bit(&fix, addr); |
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tmpmax = max + fix; |
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start += fix; |
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|
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ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix; |
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if (ret > max) |
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return max; |
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return ret; |
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} |
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|
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static inline int mb_find_next_bit(void *addr, int max, int start) |
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{ |
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int fix = 0, ret, tmpmax; |
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addr = mb_correct_addr_and_bit(&fix, addr); |
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tmpmax = max + fix; |
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start += fix; |
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|
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ret = ext4_find_next_bit(addr, tmpmax, start) - fix; |
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if (ret > max) |
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return max; |
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return ret; |
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} |
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|
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static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) |
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{ |
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char *bb; |
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|
|
BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); |
|
BUG_ON(max == NULL); |
|
|
|
if (order > e4b->bd_blkbits + 1) { |
|
*max = 0; |
|
return NULL; |
|
} |
|
|
|
/* at order 0 we see each particular block */ |
|
if (order == 0) { |
|
*max = 1 << (e4b->bd_blkbits + 3); |
|
return e4b->bd_bitmap; |
|
} |
|
|
|
bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; |
|
*max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; |
|
|
|
return bb; |
|
} |
|
|
|
#ifdef DOUBLE_CHECK |
|
static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, |
|
int first, int count) |
|
{ |
|
int i; |
|
struct super_block *sb = e4b->bd_sb; |
|
|
|
if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
|
return; |
|
assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); |
|
for (i = 0; i < count; i++) { |
|
if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { |
|
ext4_fsblk_t blocknr; |
|
|
|
blocknr = ext4_group_first_block_no(sb, e4b->bd_group); |
|
blocknr += EXT4_C2B(EXT4_SB(sb), first + i); |
|
ext4_grp_locked_error(sb, e4b->bd_group, |
|
inode ? inode->i_ino : 0, |
|
blocknr, |
|
"freeing block already freed " |
|
"(bit %u)", |
|
first + i); |
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
} |
|
mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); |
|
} |
|
} |
|
|
|
static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) |
|
{ |
|
int i; |
|
|
|
if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
|
return; |
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
|
for (i = 0; i < count; i++) { |
|
BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); |
|
mb_set_bit(first + i, e4b->bd_info->bb_bitmap); |
|
} |
|
} |
|
|
|
static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
|
{ |
|
if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
|
return; |
|
if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { |
|
unsigned char *b1, *b2; |
|
int i; |
|
b1 = (unsigned char *) e4b->bd_info->bb_bitmap; |
|
b2 = (unsigned char *) bitmap; |
|
for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { |
|
if (b1[i] != b2[i]) { |
|
ext4_msg(e4b->bd_sb, KERN_ERR, |
|
"corruption in group %u " |
|
"at byte %u(%u): %x in copy != %x " |
|
"on disk/prealloc", |
|
e4b->bd_group, i, i * 8, b1[i], b2[i]); |
|
BUG(); |
|
} |
|
} |
|
} |
|
} |
|
|
|
static void mb_group_bb_bitmap_alloc(struct super_block *sb, |
|
struct ext4_group_info *grp, ext4_group_t group) |
|
{ |
|
struct buffer_head *bh; |
|
|
|
grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS); |
|
if (!grp->bb_bitmap) |
|
return; |
|
|
|
bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR_OR_NULL(bh)) { |
|
kfree(grp->bb_bitmap); |
|
grp->bb_bitmap = NULL; |
|
return; |
|
} |
|
|
|
memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize); |
|
put_bh(bh); |
|
} |
|
|
|
static void mb_group_bb_bitmap_free(struct ext4_group_info *grp) |
|
{ |
|
kfree(grp->bb_bitmap); |
|
} |
|
|
|
#else |
|
static inline void mb_free_blocks_double(struct inode *inode, |
|
struct ext4_buddy *e4b, int first, int count) |
|
{ |
|
return; |
|
} |
|
static inline void mb_mark_used_double(struct ext4_buddy *e4b, |
|
int first, int count) |
|
{ |
|
return; |
|
} |
|
static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
|
{ |
|
return; |
|
} |
|
|
|
static inline void mb_group_bb_bitmap_alloc(struct super_block *sb, |
|
struct ext4_group_info *grp, ext4_group_t group) |
|
{ |
|
return; |
|
} |
|
|
|
static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp) |
|
{ |
|
return; |
|
} |
|
#endif |
|
|
|
#ifdef AGGRESSIVE_CHECK |
|
|
|
#define MB_CHECK_ASSERT(assert) \ |
|
do { \ |
|
if (!(assert)) { \ |
|
printk(KERN_EMERG \ |
|
"Assertion failure in %s() at %s:%d: \"%s\"\n", \ |
|
function, file, line, # assert); \ |
|
BUG(); \ |
|
} \ |
|
} while (0) |
|
|
|
static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, |
|
const char *function, int line) |
|
{ |
|
struct super_block *sb = e4b->bd_sb; |
|
int order = e4b->bd_blkbits + 1; |
|
int max; |
|
int max2; |
|
int i; |
|
int j; |
|
int k; |
|
int count; |
|
struct ext4_group_info *grp; |
|
int fragments = 0; |
|
int fstart; |
|
struct list_head *cur; |
|
void *buddy; |
|
void *buddy2; |
|
|
|
if (e4b->bd_info->bb_check_counter++ % 10) |
|
return 0; |
|
|
|
while (order > 1) { |
|
buddy = mb_find_buddy(e4b, order, &max); |
|
MB_CHECK_ASSERT(buddy); |
|
buddy2 = mb_find_buddy(e4b, order - 1, &max2); |
|
MB_CHECK_ASSERT(buddy2); |
|
MB_CHECK_ASSERT(buddy != buddy2); |
|
MB_CHECK_ASSERT(max * 2 == max2); |
|
|
|
count = 0; |
|
for (i = 0; i < max; i++) { |
|
|
|
if (mb_test_bit(i, buddy)) { |
|
/* only single bit in buddy2 may be 1 */ |
|
if (!mb_test_bit(i << 1, buddy2)) { |
|
MB_CHECK_ASSERT( |
|
mb_test_bit((i<<1)+1, buddy2)); |
|
} else if (!mb_test_bit((i << 1) + 1, buddy2)) { |
|
MB_CHECK_ASSERT( |
|
mb_test_bit(i << 1, buddy2)); |
|
} |
|
continue; |
|
} |
|
|
|
/* both bits in buddy2 must be 1 */ |
|
MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); |
|
MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); |
|
|
|
for (j = 0; j < (1 << order); j++) { |
|
k = (i * (1 << order)) + j; |
|
MB_CHECK_ASSERT( |
|
!mb_test_bit(k, e4b->bd_bitmap)); |
|
} |
|
count++; |
|
} |
|
MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); |
|
order--; |
|
} |
|
|
|
fstart = -1; |
|
buddy = mb_find_buddy(e4b, 0, &max); |
|
for (i = 0; i < max; i++) { |
|
if (!mb_test_bit(i, buddy)) { |
|
MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); |
|
if (fstart == -1) { |
|
fragments++; |
|
fstart = i; |
|
} |
|
continue; |
|
} |
|
fstart = -1; |
|
/* check used bits only */ |
|
for (j = 0; j < e4b->bd_blkbits + 1; j++) { |
|
buddy2 = mb_find_buddy(e4b, j, &max2); |
|
k = i >> j; |
|
MB_CHECK_ASSERT(k < max2); |
|
MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); |
|
} |
|
} |
|
MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); |
|
MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); |
|
|
|
grp = ext4_get_group_info(sb, e4b->bd_group); |
|
list_for_each(cur, &grp->bb_prealloc_list) { |
|
ext4_group_t groupnr; |
|
struct ext4_prealloc_space *pa; |
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); |
|
MB_CHECK_ASSERT(groupnr == e4b->bd_group); |
|
for (i = 0; i < pa->pa_len; i++) |
|
MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); |
|
} |
|
return 0; |
|
} |
|
#undef MB_CHECK_ASSERT |
|
#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ |
|
__FILE__, __func__, __LINE__) |
|
#else |
|
#define mb_check_buddy(e4b) |
|
#endif |
|
|
|
/* |
|
* Divide blocks started from @first with length @len into |
|
* smaller chunks with power of 2 blocks. |
|
* Clear the bits in bitmap which the blocks of the chunk(s) covered, |
|
* then increase bb_counters[] for corresponded chunk size. |
|
*/ |
|
static void ext4_mb_mark_free_simple(struct super_block *sb, |
|
void *buddy, ext4_grpblk_t first, ext4_grpblk_t len, |
|
struct ext4_group_info *grp) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
ext4_grpblk_t min; |
|
ext4_grpblk_t max; |
|
ext4_grpblk_t chunk; |
|
unsigned int border; |
|
|
|
BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb)); |
|
|
|
border = 2 << sb->s_blocksize_bits; |
|
|
|
while (len > 0) { |
|
/* find how many blocks can be covered since this position */ |
|
max = ffs(first | border) - 1; |
|
|
|
/* find how many blocks of power 2 we need to mark */ |
|
min = fls(len) - 1; |
|
|
|
if (max < min) |
|
min = max; |
|
chunk = 1 << min; |
|
|
|
/* mark multiblock chunks only */ |
|
grp->bb_counters[min]++; |
|
if (min > 0) |
|
mb_clear_bit(first >> min, |
|
buddy + sbi->s_mb_offsets[min]); |
|
|
|
len -= chunk; |
|
first += chunk; |
|
} |
|
} |
|
|
|
static void ext4_mb_rb_insert(struct rb_root *root, struct rb_node *new, |
|
int (*cmp)(struct rb_node *, struct rb_node *)) |
|
{ |
|
struct rb_node **iter = &root->rb_node, *parent = NULL; |
|
|
|
while (*iter) { |
|
parent = *iter; |
|
if (cmp(new, *iter) > 0) |
|
iter = &((*iter)->rb_left); |
|
else |
|
iter = &((*iter)->rb_right); |
|
} |
|
|
|
rb_link_node(new, parent, iter); |
|
rb_insert_color(new, root); |
|
} |
|
|
|
static int |
|
ext4_mb_avg_fragment_size_cmp(struct rb_node *rb1, struct rb_node *rb2) |
|
{ |
|
struct ext4_group_info *grp1 = rb_entry(rb1, |
|
struct ext4_group_info, |
|
bb_avg_fragment_size_rb); |
|
struct ext4_group_info *grp2 = rb_entry(rb2, |
|
struct ext4_group_info, |
|
bb_avg_fragment_size_rb); |
|
int num_frags_1, num_frags_2; |
|
|
|
num_frags_1 = grp1->bb_fragments ? |
|
grp1->bb_free / grp1->bb_fragments : 0; |
|
num_frags_2 = grp2->bb_fragments ? |
|
grp2->bb_free / grp2->bb_fragments : 0; |
|
|
|
return (num_frags_2 - num_frags_1); |
|
} |
|
|
|
/* |
|
* Reinsert grpinfo into the avg_fragment_size tree with new average |
|
* fragment size. |
|
*/ |
|
static void |
|
mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
|
|
if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0) |
|
return; |
|
|
|
write_lock(&sbi->s_mb_rb_lock); |
|
if (!RB_EMPTY_NODE(&grp->bb_avg_fragment_size_rb)) { |
|
rb_erase(&grp->bb_avg_fragment_size_rb, |
|
&sbi->s_mb_avg_fragment_size_root); |
|
RB_CLEAR_NODE(&grp->bb_avg_fragment_size_rb); |
|
} |
|
|
|
ext4_mb_rb_insert(&sbi->s_mb_avg_fragment_size_root, |
|
&grp->bb_avg_fragment_size_rb, |
|
ext4_mb_avg_fragment_size_cmp); |
|
write_unlock(&sbi->s_mb_rb_lock); |
|
} |
|
|
|
/* |
|
* Choose next group by traversing largest_free_order lists. Updates *new_cr if |
|
* cr level needs an update. |
|
*/ |
|
static void ext4_mb_choose_next_group_cr0(struct ext4_allocation_context *ac, |
|
int *new_cr, ext4_group_t *group, ext4_group_t ngroups) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
struct ext4_group_info *iter, *grp; |
|
int i; |
|
|
|
if (ac->ac_status == AC_STATUS_FOUND) |
|
return; |
|
|
|
if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR0_OPTIMIZED)) |
|
atomic_inc(&sbi->s_bal_cr0_bad_suggestions); |
|
|
|
grp = NULL; |
|
for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) { |
|
if (list_empty(&sbi->s_mb_largest_free_orders[i])) |
|
continue; |
|
read_lock(&sbi->s_mb_largest_free_orders_locks[i]); |
|
if (list_empty(&sbi->s_mb_largest_free_orders[i])) { |
|
read_unlock(&sbi->s_mb_largest_free_orders_locks[i]); |
|
continue; |
|
} |
|
grp = NULL; |
|
list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i], |
|
bb_largest_free_order_node) { |
|
if (sbi->s_mb_stats) |
|
atomic64_inc(&sbi->s_bal_cX_groups_considered[0]); |
|
if (likely(ext4_mb_good_group(ac, iter->bb_group, 0))) { |
|
grp = iter; |
|
break; |
|
} |
|
} |
|
read_unlock(&sbi->s_mb_largest_free_orders_locks[i]); |
|
if (grp) |
|
break; |
|
} |
|
|
|
if (!grp) { |
|
/* Increment cr and search again */ |
|
*new_cr = 1; |
|
} else { |
|
*group = grp->bb_group; |
|
ac->ac_last_optimal_group = *group; |
|
ac->ac_flags |= EXT4_MB_CR0_OPTIMIZED; |
|
} |
|
} |
|
|
|
/* |
|
* Choose next group by traversing average fragment size tree. Updates *new_cr |
|
* if cr lvel needs an update. Sets EXT4_MB_SEARCH_NEXT_LINEAR to indicate that |
|
* the linear search should continue for one iteration since there's lock |
|
* contention on the rb tree lock. |
|
*/ |
|
static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac, |
|
int *new_cr, ext4_group_t *group, ext4_group_t ngroups) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
int avg_fragment_size, best_so_far; |
|
struct rb_node *node, *found; |
|
struct ext4_group_info *grp; |
|
|
|
/* |
|
* If there is contention on the lock, instead of waiting for the lock |
|
* to become available, just continue searching lineraly. We'll resume |
|
* our rb tree search later starting at ac->ac_last_optimal_group. |
|
*/ |
|
if (!read_trylock(&sbi->s_mb_rb_lock)) { |
|
ac->ac_flags |= EXT4_MB_SEARCH_NEXT_LINEAR; |
|
return; |
|
} |
|
|
|
if (unlikely(ac->ac_flags & EXT4_MB_CR1_OPTIMIZED)) { |
|
if (sbi->s_mb_stats) |
|
atomic_inc(&sbi->s_bal_cr1_bad_suggestions); |
|
/* We have found something at CR 1 in the past */ |
|
grp = ext4_get_group_info(ac->ac_sb, ac->ac_last_optimal_group); |
|
for (found = rb_next(&grp->bb_avg_fragment_size_rb); found != NULL; |
|
found = rb_next(found)) { |
|
grp = rb_entry(found, struct ext4_group_info, |
|
bb_avg_fragment_size_rb); |
|
if (sbi->s_mb_stats) |
|
atomic64_inc(&sbi->s_bal_cX_groups_considered[1]); |
|
if (likely(ext4_mb_good_group(ac, grp->bb_group, 1))) |
|
break; |
|
} |
|
goto done; |
|
} |
|
|
|
node = sbi->s_mb_avg_fragment_size_root.rb_node; |
|
best_so_far = 0; |
|
found = NULL; |
|
|
|
while (node) { |
|
grp = rb_entry(node, struct ext4_group_info, |
|
bb_avg_fragment_size_rb); |
|
avg_fragment_size = 0; |
|
if (ext4_mb_good_group(ac, grp->bb_group, 1)) { |
|
avg_fragment_size = grp->bb_fragments ? |
|
grp->bb_free / grp->bb_fragments : 0; |
|
if (!best_so_far || avg_fragment_size < best_so_far) { |
|
best_so_far = avg_fragment_size; |
|
found = node; |
|
} |
|
} |
|
if (avg_fragment_size > ac->ac_g_ex.fe_len) |
|
node = node->rb_right; |
|
else |
|
node = node->rb_left; |
|
} |
|
|
|
done: |
|
if (found) { |
|
grp = rb_entry(found, struct ext4_group_info, |
|
bb_avg_fragment_size_rb); |
|
*group = grp->bb_group; |
|
ac->ac_flags |= EXT4_MB_CR1_OPTIMIZED; |
|
} else { |
|
*new_cr = 2; |
|
} |
|
|
|
read_unlock(&sbi->s_mb_rb_lock); |
|
ac->ac_last_optimal_group = *group; |
|
} |
|
|
|
static inline int should_optimize_scan(struct ext4_allocation_context *ac) |
|
{ |
|
if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN))) |
|
return 0; |
|
if (ac->ac_criteria >= 2) |
|
return 0; |
|
if (ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
/* |
|
* Return next linear group for allocation. If linear traversal should not be |
|
* performed, this function just returns the same group |
|
*/ |
|
static int |
|
next_linear_group(struct ext4_allocation_context *ac, int group, int ngroups) |
|
{ |
|
if (!should_optimize_scan(ac)) |
|
goto inc_and_return; |
|
|
|
if (ac->ac_groups_linear_remaining) { |
|
ac->ac_groups_linear_remaining--; |
|
goto inc_and_return; |
|
} |
|
|
|
if (ac->ac_flags & EXT4_MB_SEARCH_NEXT_LINEAR) { |
|
ac->ac_flags &= ~EXT4_MB_SEARCH_NEXT_LINEAR; |
|
goto inc_and_return; |
|
} |
|
|
|
return group; |
|
inc_and_return: |
|
/* |
|
* Artificially restricted ngroups for non-extent |
|
* files makes group > ngroups possible on first loop. |
|
*/ |
|
return group + 1 >= ngroups ? 0 : group + 1; |
|
} |
|
|
|
/* |
|
* ext4_mb_choose_next_group: choose next group for allocation. |
|
* |
|
* @ac Allocation Context |
|
* @new_cr This is an output parameter. If the there is no good group |
|
* available at current CR level, this field is updated to indicate |
|
* the new cr level that should be used. |
|
* @group This is an input / output parameter. As an input it indicates the |
|
* next group that the allocator intends to use for allocation. As |
|
* output, this field indicates the next group that should be used as |
|
* determined by the optimization functions. |
|
* @ngroups Total number of groups |
|
*/ |
|
static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac, |
|
int *new_cr, ext4_group_t *group, ext4_group_t ngroups) |
|
{ |
|
*new_cr = ac->ac_criteria; |
|
|
|
if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining) |
|
return; |
|
|
|
if (*new_cr == 0) { |
|
ext4_mb_choose_next_group_cr0(ac, new_cr, group, ngroups); |
|
} else if (*new_cr == 1) { |
|
ext4_mb_choose_next_group_cr1(ac, new_cr, group, ngroups); |
|
} else { |
|
/* |
|
* TODO: For CR=2, we can arrange groups in an rb tree sorted by |
|
* bb_free. But until that happens, we should never come here. |
|
*/ |
|
WARN_ON(1); |
|
} |
|
} |
|
|
|
/* |
|
* Cache the order of the largest free extent we have available in this block |
|
* group. |
|
*/ |
|
static void |
|
mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
int i; |
|
|
|
if (test_opt2(sb, MB_OPTIMIZE_SCAN) && grp->bb_largest_free_order >= 0) { |
|
write_lock(&sbi->s_mb_largest_free_orders_locks[ |
|
grp->bb_largest_free_order]); |
|
list_del_init(&grp->bb_largest_free_order_node); |
|
write_unlock(&sbi->s_mb_largest_free_orders_locks[ |
|
grp->bb_largest_free_order]); |
|
} |
|
grp->bb_largest_free_order = -1; /* uninit */ |
|
|
|
for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--) { |
|
if (grp->bb_counters[i] > 0) { |
|
grp->bb_largest_free_order = i; |
|
break; |
|
} |
|
} |
|
if (test_opt2(sb, MB_OPTIMIZE_SCAN) && |
|
grp->bb_largest_free_order >= 0 && grp->bb_free) { |
|
write_lock(&sbi->s_mb_largest_free_orders_locks[ |
|
grp->bb_largest_free_order]); |
|
list_add_tail(&grp->bb_largest_free_order_node, |
|
&sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]); |
|
write_unlock(&sbi->s_mb_largest_free_orders_locks[ |
|
grp->bb_largest_free_order]); |
|
} |
|
} |
|
|
|
static noinline_for_stack |
|
void ext4_mb_generate_buddy(struct super_block *sb, |
|
void *buddy, void *bitmap, ext4_group_t group) |
|
{ |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); |
|
ext4_grpblk_t i = 0; |
|
ext4_grpblk_t first; |
|
ext4_grpblk_t len; |
|
unsigned free = 0; |
|
unsigned fragments = 0; |
|
unsigned long long period = get_cycles(); |
|
|
|
/* initialize buddy from bitmap which is aggregation |
|
* of on-disk bitmap and preallocations */ |
|
i = mb_find_next_zero_bit(bitmap, max, 0); |
|
grp->bb_first_free = i; |
|
while (i < max) { |
|
fragments++; |
|
first = i; |
|
i = mb_find_next_bit(bitmap, max, i); |
|
len = i - first; |
|
free += len; |
|
if (len > 1) |
|
ext4_mb_mark_free_simple(sb, buddy, first, len, grp); |
|
else |
|
grp->bb_counters[0]++; |
|
if (i < max) |
|
i = mb_find_next_zero_bit(bitmap, max, i); |
|
} |
|
grp->bb_fragments = fragments; |
|
|
|
if (free != grp->bb_free) { |
|
ext4_grp_locked_error(sb, group, 0, 0, |
|
"block bitmap and bg descriptor " |
|
"inconsistent: %u vs %u free clusters", |
|
free, grp->bb_free); |
|
/* |
|
* If we intend to continue, we consider group descriptor |
|
* corrupt and update bb_free using bitmap value |
|
*/ |
|
grp->bb_free = free; |
|
ext4_mark_group_bitmap_corrupted(sb, group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
} |
|
mb_set_largest_free_order(sb, grp); |
|
|
|
clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); |
|
|
|
period = get_cycles() - period; |
|
atomic_inc(&sbi->s_mb_buddies_generated); |
|
atomic64_add(period, &sbi->s_mb_generation_time); |
|
mb_update_avg_fragment_size(sb, grp); |
|
} |
|
|
|
/* The buddy information is attached the buddy cache inode |
|
* for convenience. The information regarding each group |
|
* is loaded via ext4_mb_load_buddy. The information involve |
|
* block bitmap and buddy information. The information are |
|
* stored in the inode as |
|
* |
|
* { page } |
|
* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... |
|
* |
|
* |
|
* one block each for bitmap and buddy information. |
|
* So for each group we take up 2 blocks. A page can |
|
* contain blocks_per_page (PAGE_SIZE / blocksize) blocks. |
|
* So it can have information regarding groups_per_page which |
|
* is blocks_per_page/2 |
|
* |
|
* Locking note: This routine takes the block group lock of all groups |
|
* for this page; do not hold this lock when calling this routine! |
|
*/ |
|
|
|
static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp) |
|
{ |
|
ext4_group_t ngroups; |
|
int blocksize; |
|
int blocks_per_page; |
|
int groups_per_page; |
|
int err = 0; |
|
int i; |
|
ext4_group_t first_group, group; |
|
int first_block; |
|
struct super_block *sb; |
|
struct buffer_head *bhs; |
|
struct buffer_head **bh = NULL; |
|
struct inode *inode; |
|
char *data; |
|
char *bitmap; |
|
struct ext4_group_info *grinfo; |
|
|
|
inode = page->mapping->host; |
|
sb = inode->i_sb; |
|
ngroups = ext4_get_groups_count(sb); |
|
blocksize = i_blocksize(inode); |
|
blocks_per_page = PAGE_SIZE / blocksize; |
|
|
|
mb_debug(sb, "init page %lu\n", page->index); |
|
|
|
groups_per_page = blocks_per_page >> 1; |
|
if (groups_per_page == 0) |
|
groups_per_page = 1; |
|
|
|
/* allocate buffer_heads to read bitmaps */ |
|
if (groups_per_page > 1) { |
|
i = sizeof(struct buffer_head *) * groups_per_page; |
|
bh = kzalloc(i, gfp); |
|
if (bh == NULL) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
} else |
|
bh = &bhs; |
|
|
|
first_group = page->index * blocks_per_page / 2; |
|
|
|
/* read all groups the page covers into the cache */ |
|
for (i = 0, group = first_group; i < groups_per_page; i++, group++) { |
|
if (group >= ngroups) |
|
break; |
|
|
|
grinfo = ext4_get_group_info(sb, group); |
|
/* |
|
* If page is uptodate then we came here after online resize |
|
* which added some new uninitialized group info structs, so |
|
* we must skip all initialized uptodate buddies on the page, |
|
* which may be currently in use by an allocating task. |
|
*/ |
|
if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) { |
|
bh[i] = NULL; |
|
continue; |
|
} |
|
bh[i] = ext4_read_block_bitmap_nowait(sb, group, false); |
|
if (IS_ERR(bh[i])) { |
|
err = PTR_ERR(bh[i]); |
|
bh[i] = NULL; |
|
goto out; |
|
} |
|
mb_debug(sb, "read bitmap for group %u\n", group); |
|
} |
|
|
|
/* wait for I/O completion */ |
|
for (i = 0, group = first_group; i < groups_per_page; i++, group++) { |
|
int err2; |
|
|
|
if (!bh[i]) |
|
continue; |
|
err2 = ext4_wait_block_bitmap(sb, group, bh[i]); |
|
if (!err) |
|
err = err2; |
|
} |
|
|
|
first_block = page->index * blocks_per_page; |
|
for (i = 0; i < blocks_per_page; i++) { |
|
group = (first_block + i) >> 1; |
|
if (group >= ngroups) |
|
break; |
|
|
|
if (!bh[group - first_group]) |
|
/* skip initialized uptodate buddy */ |
|
continue; |
|
|
|
if (!buffer_verified(bh[group - first_group])) |
|
/* Skip faulty bitmaps */ |
|
continue; |
|
err = 0; |
|
|
|
/* |
|
* data carry information regarding this |
|
* particular group in the format specified |
|
* above |
|
* |
|
*/ |
|
data = page_address(page) + (i * blocksize); |
|
bitmap = bh[group - first_group]->b_data; |
|
|
|
/* |
|
* We place the buddy block and bitmap block |
|
* close together |
|
*/ |
|
if ((first_block + i) & 1) { |
|
/* this is block of buddy */ |
|
BUG_ON(incore == NULL); |
|
mb_debug(sb, "put buddy for group %u in page %lu/%x\n", |
|
group, page->index, i * blocksize); |
|
trace_ext4_mb_buddy_bitmap_load(sb, group); |
|
grinfo = ext4_get_group_info(sb, group); |
|
grinfo->bb_fragments = 0; |
|
memset(grinfo->bb_counters, 0, |
|
sizeof(*grinfo->bb_counters) * |
|
(MB_NUM_ORDERS(sb))); |
|
/* |
|
* incore got set to the group block bitmap below |
|
*/ |
|
ext4_lock_group(sb, group); |
|
/* init the buddy */ |
|
memset(data, 0xff, blocksize); |
|
ext4_mb_generate_buddy(sb, data, incore, group); |
|
ext4_unlock_group(sb, group); |
|
incore = NULL; |
|
} else { |
|
/* this is block of bitmap */ |
|
BUG_ON(incore != NULL); |
|
mb_debug(sb, "put bitmap for group %u in page %lu/%x\n", |
|
group, page->index, i * blocksize); |
|
trace_ext4_mb_bitmap_load(sb, group); |
|
|
|
/* see comments in ext4_mb_put_pa() */ |
|
ext4_lock_group(sb, group); |
|
memcpy(data, bitmap, blocksize); |
|
|
|
/* mark all preallocated blks used in in-core bitmap */ |
|
ext4_mb_generate_from_pa(sb, data, group); |
|
ext4_mb_generate_from_freelist(sb, data, group); |
|
ext4_unlock_group(sb, group); |
|
|
|
/* set incore so that the buddy information can be |
|
* generated using this |
|
*/ |
|
incore = data; |
|
} |
|
} |
|
SetPageUptodate(page); |
|
|
|
out: |
|
if (bh) { |
|
for (i = 0; i < groups_per_page; i++) |
|
brelse(bh[i]); |
|
if (bh != &bhs) |
|
kfree(bh); |
|
} |
|
return err; |
|
} |
|
|
|
/* |
|
* Lock the buddy and bitmap pages. This make sure other parallel init_group |
|
* on the same buddy page doesn't happen whild holding the buddy page lock. |
|
* Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap |
|
* are on the same page e4b->bd_buddy_page is NULL and return value is 0. |
|
*/ |
|
static int ext4_mb_get_buddy_page_lock(struct super_block *sb, |
|
ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp) |
|
{ |
|
struct inode *inode = EXT4_SB(sb)->s_buddy_cache; |
|
int block, pnum, poff; |
|
int blocks_per_page; |
|
struct page *page; |
|
|
|
e4b->bd_buddy_page = NULL; |
|
e4b->bd_bitmap_page = NULL; |
|
|
|
blocks_per_page = PAGE_SIZE / sb->s_blocksize; |
|
/* |
|
* the buddy cache inode stores the block bitmap |
|
* and buddy information in consecutive blocks. |
|
* So for each group we need two blocks. |
|
*/ |
|
block = group * 2; |
|
pnum = block / blocks_per_page; |
|
poff = block % blocks_per_page; |
|
page = find_or_create_page(inode->i_mapping, pnum, gfp); |
|
if (!page) |
|
return -ENOMEM; |
|
BUG_ON(page->mapping != inode->i_mapping); |
|
e4b->bd_bitmap_page = page; |
|
e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); |
|
|
|
if (blocks_per_page >= 2) { |
|
/* buddy and bitmap are on the same page */ |
|
return 0; |
|
} |
|
|
|
block++; |
|
pnum = block / blocks_per_page; |
|
page = find_or_create_page(inode->i_mapping, pnum, gfp); |
|
if (!page) |
|
return -ENOMEM; |
|
BUG_ON(page->mapping != inode->i_mapping); |
|
e4b->bd_buddy_page = page; |
|
return 0; |
|
} |
|
|
|
static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b) |
|
{ |
|
if (e4b->bd_bitmap_page) { |
|
unlock_page(e4b->bd_bitmap_page); |
|
put_page(e4b->bd_bitmap_page); |
|
} |
|
if (e4b->bd_buddy_page) { |
|
unlock_page(e4b->bd_buddy_page); |
|
put_page(e4b->bd_buddy_page); |
|
} |
|
} |
|
|
|
/* |
|
* Locking note: This routine calls ext4_mb_init_cache(), which takes the |
|
* block group lock of all groups for this page; do not hold the BG lock when |
|
* calling this routine! |
|
*/ |
|
static noinline_for_stack |
|
int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp) |
|
{ |
|
|
|
struct ext4_group_info *this_grp; |
|
struct ext4_buddy e4b; |
|
struct page *page; |
|
int ret = 0; |
|
|
|
might_sleep(); |
|
mb_debug(sb, "init group %u\n", group); |
|
this_grp = ext4_get_group_info(sb, group); |
|
/* |
|
* This ensures that we don't reinit the buddy cache |
|
* page which map to the group from which we are already |
|
* allocating. If we are looking at the buddy cache we would |
|
* have taken a reference using ext4_mb_load_buddy and that |
|
* would have pinned buddy page to page cache. |
|
* The call to ext4_mb_get_buddy_page_lock will mark the |
|
* page accessed. |
|
*/ |
|
ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp); |
|
if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) { |
|
/* |
|
* somebody initialized the group |
|
* return without doing anything |
|
*/ |
|
goto err; |
|
} |
|
|
|
page = e4b.bd_bitmap_page; |
|
ret = ext4_mb_init_cache(page, NULL, gfp); |
|
if (ret) |
|
goto err; |
|
if (!PageUptodate(page)) { |
|
ret = -EIO; |
|
goto err; |
|
} |
|
|
|
if (e4b.bd_buddy_page == NULL) { |
|
/* |
|
* If both the bitmap and buddy are in |
|
* the same page we don't need to force |
|
* init the buddy |
|
*/ |
|
ret = 0; |
|
goto err; |
|
} |
|
/* init buddy cache */ |
|
page = e4b.bd_buddy_page; |
|
ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp); |
|
if (ret) |
|
goto err; |
|
if (!PageUptodate(page)) { |
|
ret = -EIO; |
|
goto err; |
|
} |
|
err: |
|
ext4_mb_put_buddy_page_lock(&e4b); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Locking note: This routine calls ext4_mb_init_cache(), which takes the |
|
* block group lock of all groups for this page; do not hold the BG lock when |
|
* calling this routine! |
|
*/ |
|
static noinline_for_stack int |
|
ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group, |
|
struct ext4_buddy *e4b, gfp_t gfp) |
|
{ |
|
int blocks_per_page; |
|
int block; |
|
int pnum; |
|
int poff; |
|
struct page *page; |
|
int ret; |
|
struct ext4_group_info *grp; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct inode *inode = sbi->s_buddy_cache; |
|
|
|
might_sleep(); |
|
mb_debug(sb, "load group %u\n", group); |
|
|
|
blocks_per_page = PAGE_SIZE / sb->s_blocksize; |
|
grp = ext4_get_group_info(sb, group); |
|
|
|
e4b->bd_blkbits = sb->s_blocksize_bits; |
|
e4b->bd_info = grp; |
|
e4b->bd_sb = sb; |
|
e4b->bd_group = group; |
|
e4b->bd_buddy_page = NULL; |
|
e4b->bd_bitmap_page = NULL; |
|
|
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
|
/* |
|
* we need full data about the group |
|
* to make a good selection |
|
*/ |
|
ret = ext4_mb_init_group(sb, group, gfp); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
/* |
|
* the buddy cache inode stores the block bitmap |
|
* and buddy information in consecutive blocks. |
|
* So for each group we need two blocks. |
|
*/ |
|
block = group * 2; |
|
pnum = block / blocks_per_page; |
|
poff = block % blocks_per_page; |
|
|
|
/* we could use find_or_create_page(), but it locks page |
|
* what we'd like to avoid in fast path ... */ |
|
page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED); |
|
if (page == NULL || !PageUptodate(page)) { |
|
if (page) |
|
/* |
|
* drop the page reference and try |
|
* to get the page with lock. If we |
|
* are not uptodate that implies |
|
* somebody just created the page but |
|
* is yet to initialize the same. So |
|
* wait for it to initialize. |
|
*/ |
|
put_page(page); |
|
page = find_or_create_page(inode->i_mapping, pnum, gfp); |
|
if (page) { |
|
BUG_ON(page->mapping != inode->i_mapping); |
|
if (!PageUptodate(page)) { |
|
ret = ext4_mb_init_cache(page, NULL, gfp); |
|
if (ret) { |
|
unlock_page(page); |
|
goto err; |
|
} |
|
mb_cmp_bitmaps(e4b, page_address(page) + |
|
(poff * sb->s_blocksize)); |
|
} |
|
unlock_page(page); |
|
} |
|
} |
|
if (page == NULL) { |
|
ret = -ENOMEM; |
|
goto err; |
|
} |
|
if (!PageUptodate(page)) { |
|
ret = -EIO; |
|
goto err; |
|
} |
|
|
|
/* Pages marked accessed already */ |
|
e4b->bd_bitmap_page = page; |
|
e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); |
|
|
|
block++; |
|
pnum = block / blocks_per_page; |
|
poff = block % blocks_per_page; |
|
|
|
page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED); |
|
if (page == NULL || !PageUptodate(page)) { |
|
if (page) |
|
put_page(page); |
|
page = find_or_create_page(inode->i_mapping, pnum, gfp); |
|
if (page) { |
|
BUG_ON(page->mapping != inode->i_mapping); |
|
if (!PageUptodate(page)) { |
|
ret = ext4_mb_init_cache(page, e4b->bd_bitmap, |
|
gfp); |
|
if (ret) { |
|
unlock_page(page); |
|
goto err; |
|
} |
|
} |
|
unlock_page(page); |
|
} |
|
} |
|
if (page == NULL) { |
|
ret = -ENOMEM; |
|
goto err; |
|
} |
|
if (!PageUptodate(page)) { |
|
ret = -EIO; |
|
goto err; |
|
} |
|
|
|
/* Pages marked accessed already */ |
|
e4b->bd_buddy_page = page; |
|
e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize); |
|
|
|
return 0; |
|
|
|
err: |
|
if (page) |
|
put_page(page); |
|
if (e4b->bd_bitmap_page) |
|
put_page(e4b->bd_bitmap_page); |
|
if (e4b->bd_buddy_page) |
|
put_page(e4b->bd_buddy_page); |
|
e4b->bd_buddy = NULL; |
|
e4b->bd_bitmap = NULL; |
|
return ret; |
|
} |
|
|
|
static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, |
|
struct ext4_buddy *e4b) |
|
{ |
|
return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS); |
|
} |
|
|
|
static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) |
|
{ |
|
if (e4b->bd_bitmap_page) |
|
put_page(e4b->bd_bitmap_page); |
|
if (e4b->bd_buddy_page) |
|
put_page(e4b->bd_buddy_page); |
|
} |
|
|
|
|
|
static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) |
|
{ |
|
int order = 1, max; |
|
void *bb; |
|
|
|
BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); |
|
BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); |
|
|
|
while (order <= e4b->bd_blkbits + 1) { |
|
bb = mb_find_buddy(e4b, order, &max); |
|
if (!mb_test_bit(block >> order, bb)) { |
|
/* this block is part of buddy of order 'order' */ |
|
return order; |
|
} |
|
order++; |
|
} |
|
return 0; |
|
} |
|
|
|
static void mb_clear_bits(void *bm, int cur, int len) |
|
{ |
|
__u32 *addr; |
|
|
|
len = cur + len; |
|
while (cur < len) { |
|
if ((cur & 31) == 0 && (len - cur) >= 32) { |
|
/* fast path: clear whole word at once */ |
|
addr = bm + (cur >> 3); |
|
*addr = 0; |
|
cur += 32; |
|
continue; |
|
} |
|
mb_clear_bit(cur, bm); |
|
cur++; |
|
} |
|
} |
|
|
|
/* clear bits in given range |
|
* will return first found zero bit if any, -1 otherwise |
|
*/ |
|
static int mb_test_and_clear_bits(void *bm, int cur, int len) |
|
{ |
|
__u32 *addr; |
|
int zero_bit = -1; |
|
|
|
len = cur + len; |
|
while (cur < len) { |
|
if ((cur & 31) == 0 && (len - cur) >= 32) { |
|
/* fast path: clear whole word at once */ |
|
addr = bm + (cur >> 3); |
|
if (*addr != (__u32)(-1) && zero_bit == -1) |
|
zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0); |
|
*addr = 0; |
|
cur += 32; |
|
continue; |
|
} |
|
if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1) |
|
zero_bit = cur; |
|
cur++; |
|
} |
|
|
|
return zero_bit; |
|
} |
|
|
|
void ext4_set_bits(void *bm, int cur, int len) |
|
{ |
|
__u32 *addr; |
|
|
|
len = cur + len; |
|
while (cur < len) { |
|
if ((cur & 31) == 0 && (len - cur) >= 32) { |
|
/* fast path: set whole word at once */ |
|
addr = bm + (cur >> 3); |
|
*addr = 0xffffffff; |
|
cur += 32; |
|
continue; |
|
} |
|
mb_set_bit(cur, bm); |
|
cur++; |
|
} |
|
} |
|
|
|
static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side) |
|
{ |
|
if (mb_test_bit(*bit + side, bitmap)) { |
|
mb_clear_bit(*bit, bitmap); |
|
(*bit) -= side; |
|
return 1; |
|
} |
|
else { |
|
(*bit) += side; |
|
mb_set_bit(*bit, bitmap); |
|
return -1; |
|
} |
|
} |
|
|
|
static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last) |
|
{ |
|
int max; |
|
int order = 1; |
|
void *buddy = mb_find_buddy(e4b, order, &max); |
|
|
|
while (buddy) { |
|
void *buddy2; |
|
|
|
/* Bits in range [first; last] are known to be set since |
|
* corresponding blocks were allocated. Bits in range |
|
* (first; last) will stay set because they form buddies on |
|
* upper layer. We just deal with borders if they don't |
|
* align with upper layer and then go up. |
|
* Releasing entire group is all about clearing |
|
* single bit of highest order buddy. |
|
*/ |
|
|
|
/* Example: |
|
* --------------------------------- |
|
* | 1 | 1 | 1 | 1 | |
|
* --------------------------------- |
|
* | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
|
* --------------------------------- |
|
* 0 1 2 3 4 5 6 7 |
|
* \_____________________/ |
|
* |
|
* Neither [1] nor [6] is aligned to above layer. |
|
* Left neighbour [0] is free, so mark it busy, |
|
* decrease bb_counters and extend range to |
|
* [0; 6] |
|
* Right neighbour [7] is busy. It can't be coaleasced with [6], so |
|
* mark [6] free, increase bb_counters and shrink range to |
|
* [0; 5]. |
|
* Then shift range to [0; 2], go up and do the same. |
|
*/ |
|
|
|
|
|
if (first & 1) |
|
e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1); |
|
if (!(last & 1)) |
|
e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1); |
|
if (first > last) |
|
break; |
|
order++; |
|
|
|
if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) { |
|
mb_clear_bits(buddy, first, last - first + 1); |
|
e4b->bd_info->bb_counters[order - 1] += last - first + 1; |
|
break; |
|
} |
|
first >>= 1; |
|
last >>= 1; |
|
buddy = buddy2; |
|
} |
|
} |
|
|
|
static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, |
|
int first, int count) |
|
{ |
|
int left_is_free = 0; |
|
int right_is_free = 0; |
|
int block; |
|
int last = first + count - 1; |
|
struct super_block *sb = e4b->bd_sb; |
|
|
|
if (WARN_ON(count == 0)) |
|
return; |
|
BUG_ON(last >= (sb->s_blocksize << 3)); |
|
assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); |
|
/* Don't bother if the block group is corrupt. */ |
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) |
|
return; |
|
|
|
mb_check_buddy(e4b); |
|
mb_free_blocks_double(inode, e4b, first, count); |
|
|
|
this_cpu_inc(discard_pa_seq); |
|
e4b->bd_info->bb_free += count; |
|
if (first < e4b->bd_info->bb_first_free) |
|
e4b->bd_info->bb_first_free = first; |
|
|
|
/* access memory sequentially: check left neighbour, |
|
* clear range and then check right neighbour |
|
*/ |
|
if (first != 0) |
|
left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap); |
|
block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count); |
|
if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0]) |
|
right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap); |
|
|
|
if (unlikely(block != -1)) { |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
ext4_fsblk_t blocknr; |
|
|
|
blocknr = ext4_group_first_block_no(sb, e4b->bd_group); |
|
blocknr += EXT4_C2B(sbi, block); |
|
if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) { |
|
ext4_grp_locked_error(sb, e4b->bd_group, |
|
inode ? inode->i_ino : 0, |
|
blocknr, |
|
"freeing already freed block (bit %u); block bitmap corrupt.", |
|
block); |
|
ext4_mark_group_bitmap_corrupted( |
|
sb, e4b->bd_group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
} |
|
goto done; |
|
} |
|
|
|
/* let's maintain fragments counter */ |
|
if (left_is_free && right_is_free) |
|
e4b->bd_info->bb_fragments--; |
|
else if (!left_is_free && !right_is_free) |
|
e4b->bd_info->bb_fragments++; |
|
|
|
/* buddy[0] == bd_bitmap is a special case, so handle |
|
* it right away and let mb_buddy_mark_free stay free of |
|
* zero order checks. |
|
* Check if neighbours are to be coaleasced, |
|
* adjust bitmap bb_counters and borders appropriately. |
|
*/ |
|
if (first & 1) { |
|
first += !left_is_free; |
|
e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1; |
|
} |
|
if (!(last & 1)) { |
|
last -= !right_is_free; |
|
e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1; |
|
} |
|
|
|
if (first <= last) |
|
mb_buddy_mark_free(e4b, first >> 1, last >> 1); |
|
|
|
done: |
|
mb_set_largest_free_order(sb, e4b->bd_info); |
|
mb_update_avg_fragment_size(sb, e4b->bd_info); |
|
mb_check_buddy(e4b); |
|
} |
|
|
|
static int mb_find_extent(struct ext4_buddy *e4b, int block, |
|
int needed, struct ext4_free_extent *ex) |
|
{ |
|
int next = block; |
|
int max, order; |
|
void *buddy; |
|
|
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
|
BUG_ON(ex == NULL); |
|
|
|
buddy = mb_find_buddy(e4b, 0, &max); |
|
BUG_ON(buddy == NULL); |
|
BUG_ON(block >= max); |
|
if (mb_test_bit(block, buddy)) { |
|
ex->fe_len = 0; |
|
ex->fe_start = 0; |
|
ex->fe_group = 0; |
|
return 0; |
|
} |
|
|
|
/* find actual order */ |
|
order = mb_find_order_for_block(e4b, block); |
|
block = block >> order; |
|
|
|
ex->fe_len = 1 << order; |
|
ex->fe_start = block << order; |
|
ex->fe_group = e4b->bd_group; |
|
|
|
/* calc difference from given start */ |
|
next = next - ex->fe_start; |
|
ex->fe_len -= next; |
|
ex->fe_start += next; |
|
|
|
while (needed > ex->fe_len && |
|
mb_find_buddy(e4b, order, &max)) { |
|
|
|
if (block + 1 >= max) |
|
break; |
|
|
|
next = (block + 1) * (1 << order); |
|
if (mb_test_bit(next, e4b->bd_bitmap)) |
|
break; |
|
|
|
order = mb_find_order_for_block(e4b, next); |
|
|
|
block = next >> order; |
|
ex->fe_len += 1 << order; |
|
} |
|
|
|
if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) { |
|
/* Should never happen! (but apparently sometimes does?!?) */ |
|
WARN_ON(1); |
|
ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0, |
|
"corruption or bug in mb_find_extent " |
|
"block=%d, order=%d needed=%d ex=%u/%d/%d@%u", |
|
block, order, needed, ex->fe_group, ex->fe_start, |
|
ex->fe_len, ex->fe_logical); |
|
ex->fe_len = 0; |
|
ex->fe_start = 0; |
|
ex->fe_group = 0; |
|
} |
|
return ex->fe_len; |
|
} |
|
|
|
static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) |
|
{ |
|
int ord; |
|
int mlen = 0; |
|
int max = 0; |
|
int cur; |
|
int start = ex->fe_start; |
|
int len = ex->fe_len; |
|
unsigned ret = 0; |
|
int len0 = len; |
|
void *buddy; |
|
|
|
BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); |
|
BUG_ON(e4b->bd_group != ex->fe_group); |
|
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
|
mb_check_buddy(e4b); |
|
mb_mark_used_double(e4b, start, len); |
|
|
|
this_cpu_inc(discard_pa_seq); |
|
e4b->bd_info->bb_free -= len; |
|
if (e4b->bd_info->bb_first_free == start) |
|
e4b->bd_info->bb_first_free += len; |
|
|
|
/* let's maintain fragments counter */ |
|
if (start != 0) |
|
mlen = !mb_test_bit(start - 1, e4b->bd_bitmap); |
|
if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) |
|
max = !mb_test_bit(start + len, e4b->bd_bitmap); |
|
if (mlen && max) |
|
e4b->bd_info->bb_fragments++; |
|
else if (!mlen && !max) |
|
e4b->bd_info->bb_fragments--; |
|
|
|
/* let's maintain buddy itself */ |
|
while (len) { |
|
ord = mb_find_order_for_block(e4b, start); |
|
|
|
if (((start >> ord) << ord) == start && len >= (1 << ord)) { |
|
/* the whole chunk may be allocated at once! */ |
|
mlen = 1 << ord; |
|
buddy = mb_find_buddy(e4b, ord, &max); |
|
BUG_ON((start >> ord) >= max); |
|
mb_set_bit(start >> ord, buddy); |
|
e4b->bd_info->bb_counters[ord]--; |
|
start += mlen; |
|
len -= mlen; |
|
BUG_ON(len < 0); |
|
continue; |
|
} |
|
|
|
/* store for history */ |
|
if (ret == 0) |
|
ret = len | (ord << 16); |
|
|
|
/* we have to split large buddy */ |
|
BUG_ON(ord <= 0); |
|
buddy = mb_find_buddy(e4b, ord, &max); |
|
mb_set_bit(start >> ord, buddy); |
|
e4b->bd_info->bb_counters[ord]--; |
|
|
|
ord--; |
|
cur = (start >> ord) & ~1U; |
|
buddy = mb_find_buddy(e4b, ord, &max); |
|
mb_clear_bit(cur, buddy); |
|
mb_clear_bit(cur + 1, buddy); |
|
e4b->bd_info->bb_counters[ord]++; |
|
e4b->bd_info->bb_counters[ord]++; |
|
} |
|
mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); |
|
|
|
mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info); |
|
ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0); |
|
mb_check_buddy(e4b); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Must be called under group lock! |
|
*/ |
|
static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
int ret; |
|
|
|
BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); |
|
BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
|
|
|
ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); |
|
ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; |
|
ret = mb_mark_used(e4b, &ac->ac_b_ex); |
|
|
|
/* preallocation can change ac_b_ex, thus we store actually |
|
* allocated blocks for history */ |
|
ac->ac_f_ex = ac->ac_b_ex; |
|
|
|
ac->ac_status = AC_STATUS_FOUND; |
|
ac->ac_tail = ret & 0xffff; |
|
ac->ac_buddy = ret >> 16; |
|
|
|
/* |
|
* take the page reference. We want the page to be pinned |
|
* so that we don't get a ext4_mb_init_cache_call for this |
|
* group until we update the bitmap. That would mean we |
|
* double allocate blocks. The reference is dropped |
|
* in ext4_mb_release_context |
|
*/ |
|
ac->ac_bitmap_page = e4b->bd_bitmap_page; |
|
get_page(ac->ac_bitmap_page); |
|
ac->ac_buddy_page = e4b->bd_buddy_page; |
|
get_page(ac->ac_buddy_page); |
|
/* store last allocated for subsequent stream allocation */ |
|
if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { |
|
spin_lock(&sbi->s_md_lock); |
|
sbi->s_mb_last_group = ac->ac_f_ex.fe_group; |
|
sbi->s_mb_last_start = ac->ac_f_ex.fe_start; |
|
spin_unlock(&sbi->s_md_lock); |
|
} |
|
/* |
|
* As we've just preallocated more space than |
|
* user requested originally, we store allocated |
|
* space in a special descriptor. |
|
*/ |
|
if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) |
|
ext4_mb_new_preallocation(ac); |
|
|
|
} |
|
|
|
static void ext4_mb_check_limits(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b, |
|
int finish_group) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
struct ext4_free_extent *bex = &ac->ac_b_ex; |
|
struct ext4_free_extent *gex = &ac->ac_g_ex; |
|
struct ext4_free_extent ex; |
|
int max; |
|
|
|
if (ac->ac_status == AC_STATUS_FOUND) |
|
return; |
|
/* |
|
* We don't want to scan for a whole year |
|
*/ |
|
if (ac->ac_found > sbi->s_mb_max_to_scan && |
|
!(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
|
ac->ac_status = AC_STATUS_BREAK; |
|
return; |
|
} |
|
|
|
/* |
|
* Haven't found good chunk so far, let's continue |
|
*/ |
|
if (bex->fe_len < gex->fe_len) |
|
return; |
|
|
|
if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) |
|
&& bex->fe_group == e4b->bd_group) { |
|
/* recheck chunk's availability - we don't know |
|
* when it was found (within this lock-unlock |
|
* period or not) */ |
|
max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex); |
|
if (max >= gex->fe_len) { |
|
ext4_mb_use_best_found(ac, e4b); |
|
return; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* The routine checks whether found extent is good enough. If it is, |
|
* then the extent gets marked used and flag is set to the context |
|
* to stop scanning. Otherwise, the extent is compared with the |
|
* previous found extent and if new one is better, then it's stored |
|
* in the context. Later, the best found extent will be used, if |
|
* mballoc can't find good enough extent. |
|
* |
|
* FIXME: real allocation policy is to be designed yet! |
|
*/ |
|
static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, |
|
struct ext4_free_extent *ex, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct ext4_free_extent *bex = &ac->ac_b_ex; |
|
struct ext4_free_extent *gex = &ac->ac_g_ex; |
|
|
|
BUG_ON(ex->fe_len <= 0); |
|
BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); |
|
BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); |
|
BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); |
|
|
|
ac->ac_found++; |
|
|
|
/* |
|
* The special case - take what you catch first |
|
*/ |
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
|
*bex = *ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
return; |
|
} |
|
|
|
/* |
|
* Let's check whether the chuck is good enough |
|
*/ |
|
if (ex->fe_len == gex->fe_len) { |
|
*bex = *ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
return; |
|
} |
|
|
|
/* |
|
* If this is first found extent, just store it in the context |
|
*/ |
|
if (bex->fe_len == 0) { |
|
*bex = *ex; |
|
return; |
|
} |
|
|
|
/* |
|
* If new found extent is better, store it in the context |
|
*/ |
|
if (bex->fe_len < gex->fe_len) { |
|
/* if the request isn't satisfied, any found extent |
|
* larger than previous best one is better */ |
|
if (ex->fe_len > bex->fe_len) |
|
*bex = *ex; |
|
} else if (ex->fe_len > gex->fe_len) { |
|
/* if the request is satisfied, then we try to find |
|
* an extent that still satisfy the request, but is |
|
* smaller than previous one */ |
|
if (ex->fe_len < bex->fe_len) |
|
*bex = *ex; |
|
} |
|
|
|
ext4_mb_check_limits(ac, e4b, 0); |
|
} |
|
|
|
static noinline_for_stack |
|
int ext4_mb_try_best_found(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct ext4_free_extent ex = ac->ac_b_ex; |
|
ext4_group_t group = ex.fe_group; |
|
int max; |
|
int err; |
|
|
|
BUG_ON(ex.fe_len <= 0); |
|
err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
|
if (err) |
|
return err; |
|
|
|
ext4_lock_group(ac->ac_sb, group); |
|
max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex); |
|
|
|
if (max > 0) { |
|
ac->ac_b_ex = ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
} |
|
|
|
ext4_unlock_group(ac->ac_sb, group); |
|
ext4_mb_unload_buddy(e4b); |
|
|
|
return 0; |
|
} |
|
|
|
static noinline_for_stack |
|
int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
ext4_group_t group = ac->ac_g_ex.fe_group; |
|
int max; |
|
int err; |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
|
struct ext4_free_extent ex; |
|
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL)) |
|
return 0; |
|
if (grp->bb_free == 0) |
|
return 0; |
|
|
|
err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
|
if (err) |
|
return err; |
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) { |
|
ext4_mb_unload_buddy(e4b); |
|
return 0; |
|
} |
|
|
|
ext4_lock_group(ac->ac_sb, group); |
|
max = mb_find_extent(e4b, ac->ac_g_ex.fe_start, |
|
ac->ac_g_ex.fe_len, &ex); |
|
ex.fe_logical = 0xDEADFA11; /* debug value */ |
|
|
|
if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) { |
|
ext4_fsblk_t start; |
|
|
|
start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) + |
|
ex.fe_start; |
|
/* use do_div to get remainder (would be 64-bit modulo) */ |
|
if (do_div(start, sbi->s_stripe) == 0) { |
|
ac->ac_found++; |
|
ac->ac_b_ex = ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
} |
|
} else if (max >= ac->ac_g_ex.fe_len) { |
|
BUG_ON(ex.fe_len <= 0); |
|
BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
|
BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
|
ac->ac_found++; |
|
ac->ac_b_ex = ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
} else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { |
|
/* Sometimes, caller may want to merge even small |
|
* number of blocks to an existing extent */ |
|
BUG_ON(ex.fe_len <= 0); |
|
BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
|
BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
|
ac->ac_found++; |
|
ac->ac_b_ex = ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
} |
|
ext4_unlock_group(ac->ac_sb, group); |
|
ext4_mb_unload_buddy(e4b); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* The routine scans buddy structures (not bitmap!) from given order |
|
* to max order and tries to find big enough chunk to satisfy the req |
|
*/ |
|
static noinline_for_stack |
|
void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_group_info *grp = e4b->bd_info; |
|
void *buddy; |
|
int i; |
|
int k; |
|
int max; |
|
|
|
BUG_ON(ac->ac_2order <= 0); |
|
for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) { |
|
if (grp->bb_counters[i] == 0) |
|
continue; |
|
|
|
buddy = mb_find_buddy(e4b, i, &max); |
|
BUG_ON(buddy == NULL); |
|
|
|
k = mb_find_next_zero_bit(buddy, max, 0); |
|
if (k >= max) { |
|
ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0, |
|
"%d free clusters of order %d. But found 0", |
|
grp->bb_counters[i], i); |
|
ext4_mark_group_bitmap_corrupted(ac->ac_sb, |
|
e4b->bd_group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
break; |
|
} |
|
ac->ac_found++; |
|
|
|
ac->ac_b_ex.fe_len = 1 << i; |
|
ac->ac_b_ex.fe_start = k << i; |
|
ac->ac_b_ex.fe_group = e4b->bd_group; |
|
|
|
ext4_mb_use_best_found(ac, e4b); |
|
|
|
BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len); |
|
|
|
if (EXT4_SB(sb)->s_mb_stats) |
|
atomic_inc(&EXT4_SB(sb)->s_bal_2orders); |
|
|
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* The routine scans the group and measures all found extents. |
|
* In order to optimize scanning, caller must pass number of |
|
* free blocks in the group, so the routine can know upper limit. |
|
*/ |
|
static noinline_for_stack |
|
void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
void *bitmap = e4b->bd_bitmap; |
|
struct ext4_free_extent ex; |
|
int i; |
|
int free; |
|
|
|
free = e4b->bd_info->bb_free; |
|
if (WARN_ON(free <= 0)) |
|
return; |
|
|
|
i = e4b->bd_info->bb_first_free; |
|
|
|
while (free && ac->ac_status == AC_STATUS_CONTINUE) { |
|
i = mb_find_next_zero_bit(bitmap, |
|
EXT4_CLUSTERS_PER_GROUP(sb), i); |
|
if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) { |
|
/* |
|
* IF we have corrupt bitmap, we won't find any |
|
* free blocks even though group info says we |
|
* have free blocks |
|
*/ |
|
ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, |
|
"%d free clusters as per " |
|
"group info. But bitmap says 0", |
|
free); |
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
break; |
|
} |
|
|
|
mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex); |
|
if (WARN_ON(ex.fe_len <= 0)) |
|
break; |
|
if (free < ex.fe_len) { |
|
ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, |
|
"%d free clusters as per " |
|
"group info. But got %d blocks", |
|
free, ex.fe_len); |
|
ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
|
/* |
|
* The number of free blocks differs. This mostly |
|
* indicate that the bitmap is corrupt. So exit |
|
* without claiming the space. |
|
*/ |
|
break; |
|
} |
|
ex.fe_logical = 0xDEADC0DE; /* debug value */ |
|
ext4_mb_measure_extent(ac, &ex, e4b); |
|
|
|
i += ex.fe_len; |
|
free -= ex.fe_len; |
|
} |
|
|
|
ext4_mb_check_limits(ac, e4b, 1); |
|
} |
|
|
|
/* |
|
* This is a special case for storages like raid5 |
|
* we try to find stripe-aligned chunks for stripe-size-multiple requests |
|
*/ |
|
static noinline_for_stack |
|
void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, |
|
struct ext4_buddy *e4b) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
void *bitmap = e4b->bd_bitmap; |
|
struct ext4_free_extent ex; |
|
ext4_fsblk_t first_group_block; |
|
ext4_fsblk_t a; |
|
ext4_grpblk_t i; |
|
int max; |
|
|
|
BUG_ON(sbi->s_stripe == 0); |
|
|
|
/* find first stripe-aligned block in group */ |
|
first_group_block = ext4_group_first_block_no(sb, e4b->bd_group); |
|
|
|
a = first_group_block + sbi->s_stripe - 1; |
|
do_div(a, sbi->s_stripe); |
|
i = (a * sbi->s_stripe) - first_group_block; |
|
|
|
while (i < EXT4_CLUSTERS_PER_GROUP(sb)) { |
|
if (!mb_test_bit(i, bitmap)) { |
|
max = mb_find_extent(e4b, i, sbi->s_stripe, &ex); |
|
if (max >= sbi->s_stripe) { |
|
ac->ac_found++; |
|
ex.fe_logical = 0xDEADF00D; /* debug value */ |
|
ac->ac_b_ex = ex; |
|
ext4_mb_use_best_found(ac, e4b); |
|
break; |
|
} |
|
} |
|
i += sbi->s_stripe; |
|
} |
|
} |
|
|
|
/* |
|
* This is also called BEFORE we load the buddy bitmap. |
|
* Returns either 1 or 0 indicating that the group is either suitable |
|
* for the allocation or not. |
|
*/ |
|
static bool ext4_mb_good_group(struct ext4_allocation_context *ac, |
|
ext4_group_t group, int cr) |
|
{ |
|
ext4_grpblk_t free, fragments; |
|
int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); |
|
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
|
|
|
BUG_ON(cr < 0 || cr >= 4); |
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) |
|
return false; |
|
|
|
free = grp->bb_free; |
|
if (free == 0) |
|
return false; |
|
|
|
fragments = grp->bb_fragments; |
|
if (fragments == 0) |
|
return false; |
|
|
|
switch (cr) { |
|
case 0: |
|
BUG_ON(ac->ac_2order == 0); |
|
|
|
/* Avoid using the first bg of a flexgroup for data files */ |
|
if ((ac->ac_flags & EXT4_MB_HINT_DATA) && |
|
(flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && |
|
((group % flex_size) == 0)) |
|
return false; |
|
|
|
if (free < ac->ac_g_ex.fe_len) |
|
return false; |
|
|
|
if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb)) |
|
return true; |
|
|
|
if (grp->bb_largest_free_order < ac->ac_2order) |
|
return false; |
|
|
|
return true; |
|
case 1: |
|
if ((free / fragments) >= ac->ac_g_ex.fe_len) |
|
return true; |
|
break; |
|
case 2: |
|
if (free >= ac->ac_g_ex.fe_len) |
|
return true; |
|
break; |
|
case 3: |
|
return true; |
|
default: |
|
BUG(); |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* This could return negative error code if something goes wrong |
|
* during ext4_mb_init_group(). This should not be called with |
|
* ext4_lock_group() held. |
|
*/ |
|
static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, |
|
ext4_group_t group, int cr) |
|
{ |
|
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK; |
|
ext4_grpblk_t free; |
|
int ret = 0; |
|
|
|
if (sbi->s_mb_stats) |
|
atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]); |
|
if (should_lock) |
|
ext4_lock_group(sb, group); |
|
free = grp->bb_free; |
|
if (free == 0) |
|
goto out; |
|
if (cr <= 2 && free < ac->ac_g_ex.fe_len) |
|
goto out; |
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) |
|
goto out; |
|
if (should_lock) |
|
ext4_unlock_group(sb, group); |
|
|
|
/* We only do this if the grp has never been initialized */ |
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
|
struct ext4_group_desc *gdp = |
|
ext4_get_group_desc(sb, group, NULL); |
|
int ret; |
|
|
|
/* cr=0/1 is a very optimistic search to find large |
|
* good chunks almost for free. If buddy data is not |
|
* ready, then this optimization makes no sense. But |
|
* we never skip the first block group in a flex_bg, |
|
* since this gets used for metadata block allocation, |
|
* and we want to make sure we locate metadata blocks |
|
* in the first block group in the flex_bg if possible. |
|
*/ |
|
if (cr < 2 && |
|
(!sbi->s_log_groups_per_flex || |
|
((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) && |
|
!(ext4_has_group_desc_csum(sb) && |
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) |
|
return 0; |
|
ret = ext4_mb_init_group(sb, group, GFP_NOFS); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
if (should_lock) |
|
ext4_lock_group(sb, group); |
|
ret = ext4_mb_good_group(ac, group, cr); |
|
out: |
|
if (should_lock) |
|
ext4_unlock_group(sb, group); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Start prefetching @nr block bitmaps starting at @group. |
|
* Return the next group which needs to be prefetched. |
|
*/ |
|
ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group, |
|
unsigned int nr, int *cnt) |
|
{ |
|
ext4_group_t ngroups = ext4_get_groups_count(sb); |
|
struct buffer_head *bh; |
|
struct blk_plug plug; |
|
|
|
blk_start_plug(&plug); |
|
while (nr-- > 0) { |
|
struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, |
|
NULL); |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
|
|
|
/* |
|
* Prefetch block groups with free blocks; but don't |
|
* bother if it is marked uninitialized on disk, since |
|
* it won't require I/O to read. Also only try to |
|
* prefetch once, so we avoid getblk() call, which can |
|
* be expensive. |
|
*/ |
|
if (!EXT4_MB_GRP_TEST_AND_SET_READ(grp) && |
|
EXT4_MB_GRP_NEED_INIT(grp) && |
|
ext4_free_group_clusters(sb, gdp) > 0 && |
|
!(ext4_has_group_desc_csum(sb) && |
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) { |
|
bh = ext4_read_block_bitmap_nowait(sb, group, true); |
|
if (bh && !IS_ERR(bh)) { |
|
if (!buffer_uptodate(bh) && cnt) |
|
(*cnt)++; |
|
brelse(bh); |
|
} |
|
} |
|
if (++group >= ngroups) |
|
group = 0; |
|
} |
|
blk_finish_plug(&plug); |
|
return group; |
|
} |
|
|
|
/* |
|
* Prefetching reads the block bitmap into the buffer cache; but we |
|
* need to make sure that the buddy bitmap in the page cache has been |
|
* initialized. Note that ext4_mb_init_group() will block if the I/O |
|
* is not yet completed, or indeed if it was not initiated by |
|
* ext4_mb_prefetch did not start the I/O. |
|
* |
|
* TODO: We should actually kick off the buddy bitmap setup in a work |
|
* queue when the buffer I/O is completed, so that we don't block |
|
* waiting for the block allocation bitmap read to finish when |
|
* ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator(). |
|
*/ |
|
void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group, |
|
unsigned int nr) |
|
{ |
|
while (nr-- > 0) { |
|
struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, |
|
NULL); |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
|
|
|
if (!group) |
|
group = ext4_get_groups_count(sb); |
|
group--; |
|
grp = ext4_get_group_info(sb, group); |
|
|
|
if (EXT4_MB_GRP_NEED_INIT(grp) && |
|
ext4_free_group_clusters(sb, gdp) > 0 && |
|
!(ext4_has_group_desc_csum(sb) && |
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) { |
|
if (ext4_mb_init_group(sb, group, GFP_NOFS)) |
|
break; |
|
} |
|
} |
|
} |
|
|
|
static noinline_for_stack int |
|
ext4_mb_regular_allocator(struct ext4_allocation_context *ac) |
|
{ |
|
ext4_group_t prefetch_grp = 0, ngroups, group, i; |
|
int cr = -1; |
|
int err = 0, first_err = 0; |
|
unsigned int nr = 0, prefetch_ios = 0; |
|
struct ext4_sb_info *sbi; |
|
struct super_block *sb; |
|
struct ext4_buddy e4b; |
|
int lost; |
|
|
|
sb = ac->ac_sb; |
|
sbi = EXT4_SB(sb); |
|
ngroups = ext4_get_groups_count(sb); |
|
/* non-extent files are limited to low blocks/groups */ |
|
if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))) |
|
ngroups = sbi->s_blockfile_groups; |
|
|
|
BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
|
|
|
/* first, try the goal */ |
|
err = ext4_mb_find_by_goal(ac, &e4b); |
|
if (err || ac->ac_status == AC_STATUS_FOUND) |
|
goto out; |
|
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
|
goto out; |
|
|
|
/* |
|
* ac->ac_2order is set only if the fe_len is a power of 2 |
|
* if ac->ac_2order is set we also set criteria to 0 so that we |
|
* try exact allocation using buddy. |
|
*/ |
|
i = fls(ac->ac_g_ex.fe_len); |
|
ac->ac_2order = 0; |
|
/* |
|
* We search using buddy data only if the order of the request |
|
* is greater than equal to the sbi_s_mb_order2_reqs |
|
* You can tune it via /sys/fs/ext4/<partition>/mb_order2_req |
|
* We also support searching for power-of-two requests only for |
|
* requests upto maximum buddy size we have constructed. |
|
*/ |
|
if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) { |
|
/* |
|
* This should tell if fe_len is exactly power of 2 |
|
*/ |
|
if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0) |
|
ac->ac_2order = array_index_nospec(i - 1, |
|
MB_NUM_ORDERS(sb)); |
|
} |
|
|
|
/* if stream allocation is enabled, use global goal */ |
|
if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { |
|
/* TBD: may be hot point */ |
|
spin_lock(&sbi->s_md_lock); |
|
ac->ac_g_ex.fe_group = sbi->s_mb_last_group; |
|
ac->ac_g_ex.fe_start = sbi->s_mb_last_start; |
|
spin_unlock(&sbi->s_md_lock); |
|
} |
|
|
|
/* Let's just scan groups to find more-less suitable blocks */ |
|
cr = ac->ac_2order ? 0 : 1; |
|
/* |
|
* cr == 0 try to get exact allocation, |
|
* cr == 3 try to get anything |
|
*/ |
|
repeat: |
|
for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) { |
|
ac->ac_criteria = cr; |
|
/* |
|
* searching for the right group start |
|
* from the goal value specified |
|
*/ |
|
group = ac->ac_g_ex.fe_group; |
|
ac->ac_last_optimal_group = group; |
|
ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups; |
|
prefetch_grp = group; |
|
|
|
for (i = 0; i < ngroups; group = next_linear_group(ac, group, ngroups), |
|
i++) { |
|
int ret = 0, new_cr; |
|
|
|
cond_resched(); |
|
|
|
ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups); |
|
if (new_cr != cr) { |
|
cr = new_cr; |
|
goto repeat; |
|
} |
|
|
|
/* |
|
* Batch reads of the block allocation bitmaps |
|
* to get multiple READs in flight; limit |
|
* prefetching at cr=0/1, otherwise mballoc can |
|
* spend a lot of time loading imperfect groups |
|
*/ |
|
if ((prefetch_grp == group) && |
|
(cr > 1 || |
|
prefetch_ios < sbi->s_mb_prefetch_limit)) { |
|
unsigned int curr_ios = prefetch_ios; |
|
|
|
nr = sbi->s_mb_prefetch; |
|
if (ext4_has_feature_flex_bg(sb)) { |
|
nr = 1 << sbi->s_log_groups_per_flex; |
|
nr -= group & (nr - 1); |
|
nr = min(nr, sbi->s_mb_prefetch); |
|
} |
|
prefetch_grp = ext4_mb_prefetch(sb, group, |
|
nr, &prefetch_ios); |
|
if (prefetch_ios == curr_ios) |
|
nr = 0; |
|
} |
|
|
|
/* This now checks without needing the buddy page */ |
|
ret = ext4_mb_good_group_nolock(ac, group, cr); |
|
if (ret <= 0) { |
|
if (!first_err) |
|
first_err = ret; |
|
continue; |
|
} |
|
|
|
err = ext4_mb_load_buddy(sb, group, &e4b); |
|
if (err) |
|
goto out; |
|
|
|
ext4_lock_group(sb, group); |
|
|
|
/* |
|
* We need to check again after locking the |
|
* block group |
|
*/ |
|
ret = ext4_mb_good_group(ac, group, cr); |
|
if (ret == 0) { |
|
ext4_unlock_group(sb, group); |
|
ext4_mb_unload_buddy(&e4b); |
|
continue; |
|
} |
|
|
|
ac->ac_groups_scanned++; |
|
if (cr == 0) |
|
ext4_mb_simple_scan_group(ac, &e4b); |
|
else if (cr == 1 && sbi->s_stripe && |
|
!(ac->ac_g_ex.fe_len % sbi->s_stripe)) |
|
ext4_mb_scan_aligned(ac, &e4b); |
|
else |
|
ext4_mb_complex_scan_group(ac, &e4b); |
|
|
|
ext4_unlock_group(sb, group); |
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
if (ac->ac_status != AC_STATUS_CONTINUE) |
|
break; |
|
} |
|
/* Processed all groups and haven't found blocks */ |
|
if (sbi->s_mb_stats && i == ngroups) |
|
atomic64_inc(&sbi->s_bal_cX_failed[cr]); |
|
} |
|
|
|
if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && |
|
!(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
|
/* |
|
* We've been searching too long. Let's try to allocate |
|
* the best chunk we've found so far |
|
*/ |
|
ext4_mb_try_best_found(ac, &e4b); |
|
if (ac->ac_status != AC_STATUS_FOUND) { |
|
/* |
|
* Someone more lucky has already allocated it. |
|
* The only thing we can do is just take first |
|
* found block(s) |
|
*/ |
|
lost = atomic_inc_return(&sbi->s_mb_lost_chunks); |
|
mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n", |
|
ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start, |
|
ac->ac_b_ex.fe_len, lost); |
|
|
|
ac->ac_b_ex.fe_group = 0; |
|
ac->ac_b_ex.fe_start = 0; |
|
ac->ac_b_ex.fe_len = 0; |
|
ac->ac_status = AC_STATUS_CONTINUE; |
|
ac->ac_flags |= EXT4_MB_HINT_FIRST; |
|
cr = 3; |
|
goto repeat; |
|
} |
|
} |
|
|
|
if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND) |
|
atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]); |
|
out: |
|
if (!err && ac->ac_status != AC_STATUS_FOUND && first_err) |
|
err = first_err; |
|
|
|
mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n", |
|
ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status, |
|
ac->ac_flags, cr, err); |
|
|
|
if (nr) |
|
ext4_mb_prefetch_fini(sb, prefetch_grp, nr); |
|
|
|
return err; |
|
} |
|
|
|
static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
ext4_group_t group; |
|
|
|
if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) |
|
return NULL; |
|
group = *pos + 1; |
|
return (void *) ((unsigned long) group); |
|
} |
|
|
|
static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
ext4_group_t group; |
|
|
|
++*pos; |
|
if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) |
|
return NULL; |
|
group = *pos + 1; |
|
return (void *) ((unsigned long) group); |
|
} |
|
|
|
static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
ext4_group_t group = (ext4_group_t) ((unsigned long) v); |
|
int i; |
|
int err, buddy_loaded = 0; |
|
struct ext4_buddy e4b; |
|
struct ext4_group_info *grinfo; |
|
unsigned char blocksize_bits = min_t(unsigned char, |
|
sb->s_blocksize_bits, |
|
EXT4_MAX_BLOCK_LOG_SIZE); |
|
struct sg { |
|
struct ext4_group_info info; |
|
ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2]; |
|
} sg; |
|
|
|
group--; |
|
if (group == 0) |
|
seq_puts(seq, "#group: free frags first [" |
|
" 2^0 2^1 2^2 2^3 2^4 2^5 2^6 " |
|
" 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n"); |
|
|
|
i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + |
|
sizeof(struct ext4_group_info); |
|
|
|
grinfo = ext4_get_group_info(sb, group); |
|
/* Load the group info in memory only if not already loaded. */ |
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) { |
|
err = ext4_mb_load_buddy(sb, group, &e4b); |
|
if (err) { |
|
seq_printf(seq, "#%-5u: I/O error\n", group); |
|
return 0; |
|
} |
|
buddy_loaded = 1; |
|
} |
|
|
|
memcpy(&sg, ext4_get_group_info(sb, group), i); |
|
|
|
if (buddy_loaded) |
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free, |
|
sg.info.bb_fragments, sg.info.bb_first_free); |
|
for (i = 0; i <= 13; i++) |
|
seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ? |
|
sg.info.bb_counters[i] : 0); |
|
seq_puts(seq, " ]\n"); |
|
|
|
return 0; |
|
} |
|
|
|
static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) |
|
{ |
|
} |
|
|
|
const struct seq_operations ext4_mb_seq_groups_ops = { |
|
.start = ext4_mb_seq_groups_start, |
|
.next = ext4_mb_seq_groups_next, |
|
.stop = ext4_mb_seq_groups_stop, |
|
.show = ext4_mb_seq_groups_show, |
|
}; |
|
|
|
int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset) |
|
{ |
|
struct super_block *sb = (struct super_block *)seq->private; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
|
|
seq_puts(seq, "mballoc:\n"); |
|
if (!sbi->s_mb_stats) { |
|
seq_puts(seq, "\tmb stats collection turned off.\n"); |
|
seq_puts(seq, "\tTo enable, please write \"1\" to sysfs file mb_stats.\n"); |
|
return 0; |
|
} |
|
seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs)); |
|
seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success)); |
|
|
|
seq_printf(seq, "\tgroups_scanned: %u\n", atomic_read(&sbi->s_bal_groups_scanned)); |
|
|
|
seq_puts(seq, "\tcr0_stats:\n"); |
|
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[0])); |
|
seq_printf(seq, "\t\tgroups_considered: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_groups_considered[0])); |
|
seq_printf(seq, "\t\tuseless_loops: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_failed[0])); |
|
seq_printf(seq, "\t\tbad_suggestions: %u\n", |
|
atomic_read(&sbi->s_bal_cr0_bad_suggestions)); |
|
|
|
seq_puts(seq, "\tcr1_stats:\n"); |
|
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[1])); |
|
seq_printf(seq, "\t\tgroups_considered: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_groups_considered[1])); |
|
seq_printf(seq, "\t\tuseless_loops: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_failed[1])); |
|
seq_printf(seq, "\t\tbad_suggestions: %u\n", |
|
atomic_read(&sbi->s_bal_cr1_bad_suggestions)); |
|
|
|
seq_puts(seq, "\tcr2_stats:\n"); |
|
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[2])); |
|
seq_printf(seq, "\t\tgroups_considered: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_groups_considered[2])); |
|
seq_printf(seq, "\t\tuseless_loops: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_failed[2])); |
|
|
|
seq_puts(seq, "\tcr3_stats:\n"); |
|
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[3])); |
|
seq_printf(seq, "\t\tgroups_considered: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_groups_considered[3])); |
|
seq_printf(seq, "\t\tuseless_loops: %llu\n", |
|
atomic64_read(&sbi->s_bal_cX_failed[3])); |
|
seq_printf(seq, "\textents_scanned: %u\n", atomic_read(&sbi->s_bal_ex_scanned)); |
|
seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals)); |
|
seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders)); |
|
seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks)); |
|
seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks)); |
|
|
|
seq_printf(seq, "\tbuddies_generated: %u/%u\n", |
|
atomic_read(&sbi->s_mb_buddies_generated), |
|
ext4_get_groups_count(sb)); |
|
seq_printf(seq, "\tbuddies_time_used: %llu\n", |
|
atomic64_read(&sbi->s_mb_generation_time)); |
|
seq_printf(seq, "\tpreallocated: %u\n", |
|
atomic_read(&sbi->s_mb_preallocated)); |
|
seq_printf(seq, "\tdiscarded: %u\n", |
|
atomic_read(&sbi->s_mb_discarded)); |
|
return 0; |
|
} |
|
|
|
static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
unsigned long position; |
|
|
|
read_lock(&EXT4_SB(sb)->s_mb_rb_lock); |
|
|
|
if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1) |
|
return NULL; |
|
position = *pos + 1; |
|
return (void *) ((unsigned long) position); |
|
} |
|
|
|
static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
unsigned long position; |
|
|
|
++*pos; |
|
if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1) |
|
return NULL; |
|
position = *pos + 1; |
|
return (void *) ((unsigned long) position); |
|
} |
|
|
|
static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
unsigned long position = ((unsigned long) v); |
|
struct ext4_group_info *grp; |
|
struct rb_node *n; |
|
unsigned int count, min, max; |
|
|
|
position--; |
|
if (position >= MB_NUM_ORDERS(sb)) { |
|
seq_puts(seq, "fragment_size_tree:\n"); |
|
n = rb_first(&sbi->s_mb_avg_fragment_size_root); |
|
if (!n) { |
|
seq_puts(seq, "\ttree_min: 0\n\ttree_max: 0\n\ttree_nodes: 0\n"); |
|
return 0; |
|
} |
|
grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb); |
|
min = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0; |
|
count = 1; |
|
while (rb_next(n)) { |
|
count++; |
|
n = rb_next(n); |
|
} |
|
grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb); |
|
max = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0; |
|
|
|
seq_printf(seq, "\ttree_min: %u\n\ttree_max: %u\n\ttree_nodes: %u\n", |
|
min, max, count); |
|
return 0; |
|
} |
|
|
|
if (position == 0) { |
|
seq_printf(seq, "optimize_scan: %d\n", |
|
test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0); |
|
seq_puts(seq, "max_free_order_lists:\n"); |
|
} |
|
count = 0; |
|
list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position], |
|
bb_largest_free_order_node) |
|
count++; |
|
seq_printf(seq, "\tlist_order_%u_groups: %u\n", |
|
(unsigned int)position, count); |
|
|
|
return 0; |
|
} |
|
|
|
static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v) |
|
{ |
|
struct super_block *sb = PDE_DATA(file_inode(seq->file)); |
|
|
|
read_unlock(&EXT4_SB(sb)->s_mb_rb_lock); |
|
} |
|
|
|
const struct seq_operations ext4_mb_seq_structs_summary_ops = { |
|
.start = ext4_mb_seq_structs_summary_start, |
|
.next = ext4_mb_seq_structs_summary_next, |
|
.stop = ext4_mb_seq_structs_summary_stop, |
|
.show = ext4_mb_seq_structs_summary_show, |
|
}; |
|
|
|
static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) |
|
{ |
|
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; |
|
struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index]; |
|
|
|
BUG_ON(!cachep); |
|
return cachep; |
|
} |
|
|
|
/* |
|
* Allocate the top-level s_group_info array for the specified number |
|
* of groups |
|
*/ |
|
int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
unsigned size; |
|
struct ext4_group_info ***old_groupinfo, ***new_groupinfo; |
|
|
|
size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >> |
|
EXT4_DESC_PER_BLOCK_BITS(sb); |
|
if (size <= sbi->s_group_info_size) |
|
return 0; |
|
|
|
size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size); |
|
new_groupinfo = kvzalloc(size, GFP_KERNEL); |
|
if (!new_groupinfo) { |
|
ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group"); |
|
return -ENOMEM; |
|
} |
|
rcu_read_lock(); |
|
old_groupinfo = rcu_dereference(sbi->s_group_info); |
|
if (old_groupinfo) |
|
memcpy(new_groupinfo, old_groupinfo, |
|
sbi->s_group_info_size * sizeof(*sbi->s_group_info)); |
|
rcu_read_unlock(); |
|
rcu_assign_pointer(sbi->s_group_info, new_groupinfo); |
|
sbi->s_group_info_size = size / sizeof(*sbi->s_group_info); |
|
if (old_groupinfo) |
|
ext4_kvfree_array_rcu(old_groupinfo); |
|
ext4_debug("allocated s_groupinfo array for %d meta_bg's\n", |
|
sbi->s_group_info_size); |
|
return 0; |
|
} |
|
|
|
/* Create and initialize ext4_group_info data for the given group. */ |
|
int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, |
|
struct ext4_group_desc *desc) |
|
{ |
|
int i; |
|
int metalen = 0; |
|
int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb); |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct ext4_group_info **meta_group_info; |
|
struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
|
|
|
/* |
|
* First check if this group is the first of a reserved block. |
|
* If it's true, we have to allocate a new table of pointers |
|
* to ext4_group_info structures |
|
*/ |
|
if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { |
|
metalen = sizeof(*meta_group_info) << |
|
EXT4_DESC_PER_BLOCK_BITS(sb); |
|
meta_group_info = kmalloc(metalen, GFP_NOFS); |
|
if (meta_group_info == NULL) { |
|
ext4_msg(sb, KERN_ERR, "can't allocate mem " |
|
"for a buddy group"); |
|
goto exit_meta_group_info; |
|
} |
|
rcu_read_lock(); |
|
rcu_dereference(sbi->s_group_info)[idx] = meta_group_info; |
|
rcu_read_unlock(); |
|
} |
|
|
|
meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx); |
|
i = group & (EXT4_DESC_PER_BLOCK(sb) - 1); |
|
|
|
meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS); |
|
if (meta_group_info[i] == NULL) { |
|
ext4_msg(sb, KERN_ERR, "can't allocate buddy mem"); |
|
goto exit_group_info; |
|
} |
|
set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, |
|
&(meta_group_info[i]->bb_state)); |
|
|
|
/* |
|
* initialize bb_free to be able to skip |
|
* empty groups without initialization |
|
*/ |
|
if (ext4_has_group_desc_csum(sb) && |
|
(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { |
|
meta_group_info[i]->bb_free = |
|
ext4_free_clusters_after_init(sb, group, desc); |
|
} else { |
|
meta_group_info[i]->bb_free = |
|
ext4_free_group_clusters(sb, desc); |
|
} |
|
|
|
INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); |
|
init_rwsem(&meta_group_info[i]->alloc_sem); |
|
meta_group_info[i]->bb_free_root = RB_ROOT; |
|
INIT_LIST_HEAD(&meta_group_info[i]->bb_largest_free_order_node); |
|
RB_CLEAR_NODE(&meta_group_info[i]->bb_avg_fragment_size_rb); |
|
meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ |
|
meta_group_info[i]->bb_group = group; |
|
|
|
mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group); |
|
return 0; |
|
|
|
exit_group_info: |
|
/* If a meta_group_info table has been allocated, release it now */ |
|
if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { |
|
struct ext4_group_info ***group_info; |
|
|
|
rcu_read_lock(); |
|
group_info = rcu_dereference(sbi->s_group_info); |
|
kfree(group_info[idx]); |
|
group_info[idx] = NULL; |
|
rcu_read_unlock(); |
|
} |
|
exit_meta_group_info: |
|
return -ENOMEM; |
|
} /* ext4_mb_add_groupinfo */ |
|
|
|
static int ext4_mb_init_backend(struct super_block *sb) |
|
{ |
|
ext4_group_t ngroups = ext4_get_groups_count(sb); |
|
ext4_group_t i; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
int err; |
|
struct ext4_group_desc *desc; |
|
struct ext4_group_info ***group_info; |
|
struct kmem_cache *cachep; |
|
|
|
err = ext4_mb_alloc_groupinfo(sb, ngroups); |
|
if (err) |
|
return err; |
|
|
|
sbi->s_buddy_cache = new_inode(sb); |
|
if (sbi->s_buddy_cache == NULL) { |
|
ext4_msg(sb, KERN_ERR, "can't get new inode"); |
|
goto err_freesgi; |
|
} |
|
/* To avoid potentially colliding with an valid on-disk inode number, |
|
* use EXT4_BAD_INO for the buddy cache inode number. This inode is |
|
* not in the inode hash, so it should never be found by iget(), but |
|
* this will avoid confusion if it ever shows up during debugging. */ |
|
sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; |
|
EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; |
|
for (i = 0; i < ngroups; i++) { |
|
cond_resched(); |
|
desc = ext4_get_group_desc(sb, i, NULL); |
|
if (desc == NULL) { |
|
ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); |
|
goto err_freebuddy; |
|
} |
|
if (ext4_mb_add_groupinfo(sb, i, desc) != 0) |
|
goto err_freebuddy; |
|
} |
|
|
|
if (ext4_has_feature_flex_bg(sb)) { |
|
/* a single flex group is supposed to be read by a single IO. |
|
* 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is |
|
* unsigned integer, so the maximum shift is 32. |
|
*/ |
|
if (sbi->s_es->s_log_groups_per_flex >= 32) { |
|
ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group"); |
|
goto err_freebuddy; |
|
} |
|
sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex, |
|
BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9)); |
|
sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */ |
|
} else { |
|
sbi->s_mb_prefetch = 32; |
|
} |
|
if (sbi->s_mb_prefetch > ext4_get_groups_count(sb)) |
|
sbi->s_mb_prefetch = ext4_get_groups_count(sb); |
|
/* now many real IOs to prefetch within a single allocation at cr=0 |
|
* given cr=0 is an CPU-related optimization we shouldn't try to |
|
* load too many groups, at some point we should start to use what |
|
* we've got in memory. |
|
* with an average random access time 5ms, it'd take a second to get |
|
* 200 groups (* N with flex_bg), so let's make this limit 4 |
|
*/ |
|
sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4; |
|
if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb)) |
|
sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb); |
|
|
|
return 0; |
|
|
|
err_freebuddy: |
|
cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
|
while (i-- > 0) |
|
kmem_cache_free(cachep, ext4_get_group_info(sb, i)); |
|
i = sbi->s_group_info_size; |
|
rcu_read_lock(); |
|
group_info = rcu_dereference(sbi->s_group_info); |
|
while (i-- > 0) |
|
kfree(group_info[i]); |
|
rcu_read_unlock(); |
|
iput(sbi->s_buddy_cache); |
|
err_freesgi: |
|
rcu_read_lock(); |
|
kvfree(rcu_dereference(sbi->s_group_info)); |
|
rcu_read_unlock(); |
|
return -ENOMEM; |
|
} |
|
|
|
static void ext4_groupinfo_destroy_slabs(void) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < NR_GRPINFO_CACHES; i++) { |
|
kmem_cache_destroy(ext4_groupinfo_caches[i]); |
|
ext4_groupinfo_caches[i] = NULL; |
|
} |
|
} |
|
|
|
static int ext4_groupinfo_create_slab(size_t size) |
|
{ |
|
static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex); |
|
int slab_size; |
|
int blocksize_bits = order_base_2(size); |
|
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; |
|
struct kmem_cache *cachep; |
|
|
|
if (cache_index >= NR_GRPINFO_CACHES) |
|
return -EINVAL; |
|
|
|
if (unlikely(cache_index < 0)) |
|
cache_index = 0; |
|
|
|
mutex_lock(&ext4_grpinfo_slab_create_mutex); |
|
if (ext4_groupinfo_caches[cache_index]) { |
|
mutex_unlock(&ext4_grpinfo_slab_create_mutex); |
|
return 0; /* Already created */ |
|
} |
|
|
|
slab_size = offsetof(struct ext4_group_info, |
|
bb_counters[blocksize_bits + 2]); |
|
|
|
cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index], |
|
slab_size, 0, SLAB_RECLAIM_ACCOUNT, |
|
NULL); |
|
|
|
ext4_groupinfo_caches[cache_index] = cachep; |
|
|
|
mutex_unlock(&ext4_grpinfo_slab_create_mutex); |
|
if (!cachep) { |
|
printk(KERN_EMERG |
|
"EXT4-fs: no memory for groupinfo slab cache\n"); |
|
return -ENOMEM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
int ext4_mb_init(struct super_block *sb) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
unsigned i, j; |
|
unsigned offset, offset_incr; |
|
unsigned max; |
|
int ret; |
|
|
|
i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets); |
|
|
|
sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); |
|
if (sbi->s_mb_offsets == NULL) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs); |
|
sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); |
|
if (sbi->s_mb_maxs == NULL) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = ext4_groupinfo_create_slab(sb->s_blocksize); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* order 0 is regular bitmap */ |
|
sbi->s_mb_maxs[0] = sb->s_blocksize << 3; |
|
sbi->s_mb_offsets[0] = 0; |
|
|
|
i = 1; |
|
offset = 0; |
|
offset_incr = 1 << (sb->s_blocksize_bits - 1); |
|
max = sb->s_blocksize << 2; |
|
do { |
|
sbi->s_mb_offsets[i] = offset; |
|
sbi->s_mb_maxs[i] = max; |
|
offset += offset_incr; |
|
offset_incr = offset_incr >> 1; |
|
max = max >> 1; |
|
i++; |
|
} while (i < MB_NUM_ORDERS(sb)); |
|
|
|
sbi->s_mb_avg_fragment_size_root = RB_ROOT; |
|
sbi->s_mb_largest_free_orders = |
|
kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head), |
|
GFP_KERNEL); |
|
if (!sbi->s_mb_largest_free_orders) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
sbi->s_mb_largest_free_orders_locks = |
|
kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t), |
|
GFP_KERNEL); |
|
if (!sbi->s_mb_largest_free_orders_locks) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
for (i = 0; i < MB_NUM_ORDERS(sb); i++) { |
|
INIT_LIST_HEAD(&sbi->s_mb_largest_free_orders[i]); |
|
rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]); |
|
} |
|
rwlock_init(&sbi->s_mb_rb_lock); |
|
|
|
spin_lock_init(&sbi->s_md_lock); |
|
sbi->s_mb_free_pending = 0; |
|
INIT_LIST_HEAD(&sbi->s_freed_data_list); |
|
|
|
sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; |
|
sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; |
|
sbi->s_mb_stats = MB_DEFAULT_STATS; |
|
sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; |
|
sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; |
|
sbi->s_mb_max_inode_prealloc = MB_DEFAULT_MAX_INODE_PREALLOC; |
|
/* |
|
* The default group preallocation is 512, which for 4k block |
|
* sizes translates to 2 megabytes. However for bigalloc file |
|
* systems, this is probably too big (i.e, if the cluster size |
|
* is 1 megabyte, then group preallocation size becomes half a |
|
* gigabyte!). As a default, we will keep a two megabyte |
|
* group pralloc size for cluster sizes up to 64k, and after |
|
* that, we will force a minimum group preallocation size of |
|
* 32 clusters. This translates to 8 megs when the cluster |
|
* size is 256k, and 32 megs when the cluster size is 1 meg, |
|
* which seems reasonable as a default. |
|
*/ |
|
sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >> |
|
sbi->s_cluster_bits, 32); |
|
/* |
|
* If there is a s_stripe > 1, then we set the s_mb_group_prealloc |
|
* to the lowest multiple of s_stripe which is bigger than |
|
* the s_mb_group_prealloc as determined above. We want |
|
* the preallocation size to be an exact multiple of the |
|
* RAID stripe size so that preallocations don't fragment |
|
* the stripes. |
|
*/ |
|
if (sbi->s_stripe > 1) { |
|
sbi->s_mb_group_prealloc = roundup( |
|
sbi->s_mb_group_prealloc, sbi->s_stripe); |
|
} |
|
|
|
sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); |
|
if (sbi->s_locality_groups == NULL) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
for_each_possible_cpu(i) { |
|
struct ext4_locality_group *lg; |
|
lg = per_cpu_ptr(sbi->s_locality_groups, i); |
|
mutex_init(&lg->lg_mutex); |
|
for (j = 0; j < PREALLOC_TB_SIZE; j++) |
|
INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); |
|
spin_lock_init(&lg->lg_prealloc_lock); |
|
} |
|
|
|
if (blk_queue_nonrot(bdev_get_queue(sb->s_bdev))) |
|
sbi->s_mb_max_linear_groups = 0; |
|
else |
|
sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT; |
|
/* init file for buddy data */ |
|
ret = ext4_mb_init_backend(sb); |
|
if (ret != 0) |
|
goto out_free_locality_groups; |
|
|
|
return 0; |
|
|
|
out_free_locality_groups: |
|
free_percpu(sbi->s_locality_groups); |
|
sbi->s_locality_groups = NULL; |
|
out: |
|
kfree(sbi->s_mb_largest_free_orders); |
|
kfree(sbi->s_mb_largest_free_orders_locks); |
|
kfree(sbi->s_mb_offsets); |
|
sbi->s_mb_offsets = NULL; |
|
kfree(sbi->s_mb_maxs); |
|
sbi->s_mb_maxs = NULL; |
|
return ret; |
|
} |
|
|
|
/* need to called with the ext4 group lock held */ |
|
static int ext4_mb_cleanup_pa(struct ext4_group_info *grp) |
|
{ |
|
struct ext4_prealloc_space *pa; |
|
struct list_head *cur, *tmp; |
|
int count = 0; |
|
|
|
list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { |
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
|
list_del(&pa->pa_group_list); |
|
count++; |
|
kmem_cache_free(ext4_pspace_cachep, pa); |
|
} |
|
return count; |
|
} |
|
|
|
int ext4_mb_release(struct super_block *sb) |
|
{ |
|
ext4_group_t ngroups = ext4_get_groups_count(sb); |
|
ext4_group_t i; |
|
int num_meta_group_infos; |
|
struct ext4_group_info *grinfo, ***group_info; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
|
int count; |
|
|
|
if (sbi->s_group_info) { |
|
for (i = 0; i < ngroups; i++) { |
|
cond_resched(); |
|
grinfo = ext4_get_group_info(sb, i); |
|
mb_group_bb_bitmap_free(grinfo); |
|
ext4_lock_group(sb, i); |
|
count = ext4_mb_cleanup_pa(grinfo); |
|
if (count) |
|
mb_debug(sb, "mballoc: %d PAs left\n", |
|
count); |
|
ext4_unlock_group(sb, i); |
|
kmem_cache_free(cachep, grinfo); |
|
} |
|
num_meta_group_infos = (ngroups + |
|
EXT4_DESC_PER_BLOCK(sb) - 1) >> |
|
EXT4_DESC_PER_BLOCK_BITS(sb); |
|
rcu_read_lock(); |
|
group_info = rcu_dereference(sbi->s_group_info); |
|
for (i = 0; i < num_meta_group_infos; i++) |
|
kfree(group_info[i]); |
|
kvfree(group_info); |
|
rcu_read_unlock(); |
|
} |
|
kfree(sbi->s_mb_largest_free_orders); |
|
kfree(sbi->s_mb_largest_free_orders_locks); |
|
kfree(sbi->s_mb_offsets); |
|
kfree(sbi->s_mb_maxs); |
|
iput(sbi->s_buddy_cache); |
|
if (sbi->s_mb_stats) { |
|
ext4_msg(sb, KERN_INFO, |
|
"mballoc: %u blocks %u reqs (%u success)", |
|
atomic_read(&sbi->s_bal_allocated), |
|
atomic_read(&sbi->s_bal_reqs), |
|
atomic_read(&sbi->s_bal_success)); |
|
ext4_msg(sb, KERN_INFO, |
|
"mballoc: %u extents scanned, %u groups scanned, %u goal hits, " |
|
"%u 2^N hits, %u breaks, %u lost", |
|
atomic_read(&sbi->s_bal_ex_scanned), |
|
atomic_read(&sbi->s_bal_groups_scanned), |
|
atomic_read(&sbi->s_bal_goals), |
|
atomic_read(&sbi->s_bal_2orders), |
|
atomic_read(&sbi->s_bal_breaks), |
|
atomic_read(&sbi->s_mb_lost_chunks)); |
|
ext4_msg(sb, KERN_INFO, |
|
"mballoc: %u generated and it took %llu", |
|
atomic_read(&sbi->s_mb_buddies_generated), |
|
atomic64_read(&sbi->s_mb_generation_time)); |
|
ext4_msg(sb, KERN_INFO, |
|
"mballoc: %u preallocated, %u discarded", |
|
atomic_read(&sbi->s_mb_preallocated), |
|
atomic_read(&sbi->s_mb_discarded)); |
|
} |
|
|
|
free_percpu(sbi->s_locality_groups); |
|
|
|
return 0; |
|
} |
|
|
|
static inline int ext4_issue_discard(struct super_block *sb, |
|
ext4_group_t block_group, ext4_grpblk_t cluster, int count, |
|
struct bio **biop) |
|
{ |
|
ext4_fsblk_t discard_block; |
|
|
|
discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) + |
|
ext4_group_first_block_no(sb, block_group)); |
|
count = EXT4_C2B(EXT4_SB(sb), count); |
|
trace_ext4_discard_blocks(sb, |
|
(unsigned long long) discard_block, count); |
|
if (biop) { |
|
return __blkdev_issue_discard(sb->s_bdev, |
|
(sector_t)discard_block << (sb->s_blocksize_bits - 9), |
|
(sector_t)count << (sb->s_blocksize_bits - 9), |
|
GFP_NOFS, 0, biop); |
|
} else |
|
return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0); |
|
} |
|
|
|
static void ext4_free_data_in_buddy(struct super_block *sb, |
|
struct ext4_free_data *entry) |
|
{ |
|
struct ext4_buddy e4b; |
|
struct ext4_group_info *db; |
|
int err, count = 0, count2 = 0; |
|
|
|
mb_debug(sb, "gonna free %u blocks in group %u (0x%p):", |
|
entry->efd_count, entry->efd_group, entry); |
|
|
|
err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b); |
|
/* we expect to find existing buddy because it's pinned */ |
|
BUG_ON(err != 0); |
|
|
|
spin_lock(&EXT4_SB(sb)->s_md_lock); |
|
EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count; |
|
spin_unlock(&EXT4_SB(sb)->s_md_lock); |
|
|
|
db = e4b.bd_info; |
|
/* there are blocks to put in buddy to make them really free */ |
|
count += entry->efd_count; |
|
count2++; |
|
ext4_lock_group(sb, entry->efd_group); |
|
/* Take it out of per group rb tree */ |
|
rb_erase(&entry->efd_node, &(db->bb_free_root)); |
|
mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count); |
|
|
|
/* |
|
* Clear the trimmed flag for the group so that the next |
|
* ext4_trim_fs can trim it. |
|
* If the volume is mounted with -o discard, online discard |
|
* is supported and the free blocks will be trimmed online. |
|
*/ |
|
if (!test_opt(sb, DISCARD)) |
|
EXT4_MB_GRP_CLEAR_TRIMMED(db); |
|
|
|
if (!db->bb_free_root.rb_node) { |
|
/* No more items in the per group rb tree |
|
* balance refcounts from ext4_mb_free_metadata() |
|
*/ |
|
put_page(e4b.bd_buddy_page); |
|
put_page(e4b.bd_bitmap_page); |
|
} |
|
ext4_unlock_group(sb, entry->efd_group); |
|
kmem_cache_free(ext4_free_data_cachep, entry); |
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
mb_debug(sb, "freed %d blocks in %d structures\n", count, |
|
count2); |
|
} |
|
|
|
/* |
|
* This function is called by the jbd2 layer once the commit has finished, |
|
* so we know we can free the blocks that were released with that commit. |
|
*/ |
|
void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct ext4_free_data *entry, *tmp; |
|
struct bio *discard_bio = NULL; |
|
struct list_head freed_data_list; |
|
struct list_head *cut_pos = NULL; |
|
int err; |
|
|
|
INIT_LIST_HEAD(&freed_data_list); |
|
|
|
spin_lock(&sbi->s_md_lock); |
|
list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) { |
|
if (entry->efd_tid != commit_tid) |
|
break; |
|
cut_pos = &entry->efd_list; |
|
} |
|
if (cut_pos) |
|
list_cut_position(&freed_data_list, &sbi->s_freed_data_list, |
|
cut_pos); |
|
spin_unlock(&sbi->s_md_lock); |
|
|
|
if (test_opt(sb, DISCARD)) { |
|
list_for_each_entry(entry, &freed_data_list, efd_list) { |
|
err = ext4_issue_discard(sb, entry->efd_group, |
|
entry->efd_start_cluster, |
|
entry->efd_count, |
|
&discard_bio); |
|
if (err && err != -EOPNOTSUPP) { |
|
ext4_msg(sb, KERN_WARNING, "discard request in" |
|
" group:%d block:%d count:%d failed" |
|
" with %d", entry->efd_group, |
|
entry->efd_start_cluster, |
|
entry->efd_count, err); |
|
} else if (err == -EOPNOTSUPP) |
|
break; |
|
} |
|
|
|
if (discard_bio) { |
|
submit_bio_wait(discard_bio); |
|
bio_put(discard_bio); |
|
} |
|
} |
|
|
|
list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list) |
|
ext4_free_data_in_buddy(sb, entry); |
|
} |
|
|
|
int __init ext4_init_mballoc(void) |
|
{ |
|
ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space, |
|
SLAB_RECLAIM_ACCOUNT); |
|
if (ext4_pspace_cachep == NULL) |
|
goto out; |
|
|
|
ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context, |
|
SLAB_RECLAIM_ACCOUNT); |
|
if (ext4_ac_cachep == NULL) |
|
goto out_pa_free; |
|
|
|
ext4_free_data_cachep = KMEM_CACHE(ext4_free_data, |
|
SLAB_RECLAIM_ACCOUNT); |
|
if (ext4_free_data_cachep == NULL) |
|
goto out_ac_free; |
|
|
|
return 0; |
|
|
|
out_ac_free: |
|
kmem_cache_destroy(ext4_ac_cachep); |
|
out_pa_free: |
|
kmem_cache_destroy(ext4_pspace_cachep); |
|
out: |
|
return -ENOMEM; |
|
} |
|
|
|
void ext4_exit_mballoc(void) |
|
{ |
|
/* |
|
* Wait for completion of call_rcu()'s on ext4_pspace_cachep |
|
* before destroying the slab cache. |
|
*/ |
|
rcu_barrier(); |
|
kmem_cache_destroy(ext4_pspace_cachep); |
|
kmem_cache_destroy(ext4_ac_cachep); |
|
kmem_cache_destroy(ext4_free_data_cachep); |
|
ext4_groupinfo_destroy_slabs(); |
|
} |
|
|
|
|
|
/* |
|
* Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps |
|
* Returns 0 if success or error code |
|
*/ |
|
static noinline_for_stack int |
|
ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, |
|
handle_t *handle, unsigned int reserv_clstrs) |
|
{ |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct ext4_group_desc *gdp; |
|
struct buffer_head *gdp_bh; |
|
struct ext4_sb_info *sbi; |
|
struct super_block *sb; |
|
ext4_fsblk_t block; |
|
int err, len; |
|
|
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
|
BUG_ON(ac->ac_b_ex.fe_len <= 0); |
|
|
|
sb = ac->ac_sb; |
|
sbi = EXT4_SB(sb); |
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
bitmap_bh = NULL; |
|
goto out_err; |
|
} |
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access"); |
|
err = ext4_journal_get_write_access(handle, bitmap_bh); |
|
if (err) |
|
goto out_err; |
|
|
|
err = -EIO; |
|
gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh); |
|
if (!gdp) |
|
goto out_err; |
|
|
|
ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group, |
|
ext4_free_group_clusters(sb, gdp)); |
|
|
|
BUFFER_TRACE(gdp_bh, "get_write_access"); |
|
err = ext4_journal_get_write_access(handle, gdp_bh); |
|
if (err) |
|
goto out_err; |
|
|
|
block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
|
|
|
len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
|
if (!ext4_inode_block_valid(ac->ac_inode, block, len)) { |
|
ext4_error(sb, "Allocating blocks %llu-%llu which overlap " |
|
"fs metadata", block, block+len); |
|
/* File system mounted not to panic on error |
|
* Fix the bitmap and return EFSCORRUPTED |
|
* We leak some of the blocks here. |
|
*/ |
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
|
ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, |
|
ac->ac_b_ex.fe_len); |
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
|
if (!err) |
|
err = -EFSCORRUPTED; |
|
goto out_err; |
|
} |
|
|
|
ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
|
#ifdef AGGRESSIVE_CHECK |
|
{ |
|
int i; |
|
for (i = 0; i < ac->ac_b_ex.fe_len; i++) { |
|
BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i, |
|
bitmap_bh->b_data)); |
|
} |
|
} |
|
#endif |
|
ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, |
|
ac->ac_b_ex.fe_len); |
|
if (ext4_has_group_desc_csum(sb) && |
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { |
|
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
|
ext4_free_group_clusters_set(sb, gdp, |
|
ext4_free_clusters_after_init(sb, |
|
ac->ac_b_ex.fe_group, gdp)); |
|
} |
|
len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len; |
|
ext4_free_group_clusters_set(sb, gdp, len); |
|
ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh); |
|
ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp); |
|
|
|
ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
|
percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); |
|
/* |
|
* Now reduce the dirty block count also. Should not go negative |
|
*/ |
|
if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) |
|
/* release all the reserved blocks if non delalloc */ |
|
percpu_counter_sub(&sbi->s_dirtyclusters_counter, |
|
reserv_clstrs); |
|
|
|
if (sbi->s_log_groups_per_flex) { |
|
ext4_group_t flex_group = ext4_flex_group(sbi, |
|
ac->ac_b_ex.fe_group); |
|
atomic64_sub(ac->ac_b_ex.fe_len, |
|
&sbi_array_rcu_deref(sbi, s_flex_groups, |
|
flex_group)->free_clusters); |
|
} |
|
|
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
|
if (err) |
|
goto out_err; |
|
err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh); |
|
|
|
out_err: |
|
brelse(bitmap_bh); |
|
return err; |
|
} |
|
|
|
/* |
|
* Idempotent helper for Ext4 fast commit replay path to set the state of |
|
* blocks in bitmaps and update counters. |
|
*/ |
|
void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, |
|
int len, int state) |
|
{ |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct ext4_group_desc *gdp; |
|
struct buffer_head *gdp_bh; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
ext4_group_t group; |
|
ext4_grpblk_t blkoff; |
|
int i, clen, err; |
|
int already; |
|
|
|
clen = EXT4_B2C(sbi, len); |
|
|
|
ext4_get_group_no_and_offset(sb, block, &group, &blkoff); |
|
bitmap_bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
bitmap_bh = NULL; |
|
goto out_err; |
|
} |
|
|
|
err = -EIO; |
|
gdp = ext4_get_group_desc(sb, group, &gdp_bh); |
|
if (!gdp) |
|
goto out_err; |
|
|
|
ext4_lock_group(sb, group); |
|
already = 0; |
|
for (i = 0; i < clen; i++) |
|
if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state) |
|
already++; |
|
|
|
if (state) |
|
ext4_set_bits(bitmap_bh->b_data, blkoff, clen); |
|
else |
|
mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen); |
|
if (ext4_has_group_desc_csum(sb) && |
|
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { |
|
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
|
ext4_free_group_clusters_set(sb, gdp, |
|
ext4_free_clusters_after_init(sb, |
|
group, gdp)); |
|
} |
|
if (state) |
|
clen = ext4_free_group_clusters(sb, gdp) - clen + already; |
|
else |
|
clen = ext4_free_group_clusters(sb, gdp) + clen - already; |
|
|
|
ext4_free_group_clusters_set(sb, gdp, clen); |
|
ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh); |
|
ext4_group_desc_csum_set(sb, group, gdp); |
|
|
|
ext4_unlock_group(sb, group); |
|
|
|
if (sbi->s_log_groups_per_flex) { |
|
ext4_group_t flex_group = ext4_flex_group(sbi, group); |
|
|
|
atomic64_sub(len, |
|
&sbi_array_rcu_deref(sbi, s_flex_groups, |
|
flex_group)->free_clusters); |
|
} |
|
|
|
err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh); |
|
if (err) |
|
goto out_err; |
|
sync_dirty_buffer(bitmap_bh); |
|
err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh); |
|
sync_dirty_buffer(gdp_bh); |
|
|
|
out_err: |
|
brelse(bitmap_bh); |
|
} |
|
|
|
/* |
|
* here we normalize request for locality group |
|
* Group request are normalized to s_mb_group_prealloc, which goes to |
|
* s_strip if we set the same via mount option. |
|
* s_mb_group_prealloc can be configured via |
|
* /sys/fs/ext4/<partition>/mb_group_prealloc |
|
* |
|
* XXX: should we try to preallocate more than the group has now? |
|
*/ |
|
static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_locality_group *lg = ac->ac_lg; |
|
|
|
BUG_ON(lg == NULL); |
|
ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; |
|
mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len); |
|
} |
|
|
|
/* |
|
* Normalization means making request better in terms of |
|
* size and alignment |
|
*/ |
|
static noinline_for_stack void |
|
ext4_mb_normalize_request(struct ext4_allocation_context *ac, |
|
struct ext4_allocation_request *ar) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
int bsbits, max; |
|
ext4_lblk_t end; |
|
loff_t size, start_off; |
|
loff_t orig_size __maybe_unused; |
|
ext4_lblk_t start; |
|
struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
|
struct ext4_prealloc_space *pa; |
|
|
|
/* do normalize only data requests, metadata requests |
|
do not need preallocation */ |
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
|
return; |
|
|
|
/* sometime caller may want exact blocks */ |
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
|
return; |
|
|
|
/* caller may indicate that preallocation isn't |
|
* required (it's a tail, for example) */ |
|
if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) |
|
return; |
|
|
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { |
|
ext4_mb_normalize_group_request(ac); |
|
return ; |
|
} |
|
|
|
bsbits = ac->ac_sb->s_blocksize_bits; |
|
|
|
/* first, let's learn actual file size |
|
* given current request is allocated */ |
|
size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); |
|
size = size << bsbits; |
|
if (size < i_size_read(ac->ac_inode)) |
|
size = i_size_read(ac->ac_inode); |
|
orig_size = size; |
|
|
|
/* max size of free chunks */ |
|
max = 2 << bsbits; |
|
|
|
#define NRL_CHECK_SIZE(req, size, max, chunk_size) \ |
|
(req <= (size) || max <= (chunk_size)) |
|
|
|
/* first, try to predict filesize */ |
|
/* XXX: should this table be tunable? */ |
|
start_off = 0; |
|
if (size <= 16 * 1024) { |
|
size = 16 * 1024; |
|
} else if (size <= 32 * 1024) { |
|
size = 32 * 1024; |
|
} else if (size <= 64 * 1024) { |
|
size = 64 * 1024; |
|
} else if (size <= 128 * 1024) { |
|
size = 128 * 1024; |
|
} else if (size <= 256 * 1024) { |
|
size = 256 * 1024; |
|
} else if (size <= 512 * 1024) { |
|
size = 512 * 1024; |
|
} else if (size <= 1024 * 1024) { |
|
size = 1024 * 1024; |
|
} else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { |
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
|
(21 - bsbits)) << 21; |
|
size = 2 * 1024 * 1024; |
|
} else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { |
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
|
(22 - bsbits)) << 22; |
|
size = 4 * 1024 * 1024; |
|
} else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, |
|
(8<<20)>>bsbits, max, 8 * 1024)) { |
|
start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
|
(23 - bsbits)) << 23; |
|
size = 8 * 1024 * 1024; |
|
} else { |
|
start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits; |
|
size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb), |
|
ac->ac_o_ex.fe_len) << bsbits; |
|
} |
|
size = size >> bsbits; |
|
start = start_off >> bsbits; |
|
|
|
/* don't cover already allocated blocks in selected range */ |
|
if (ar->pleft && start <= ar->lleft) { |
|
size -= ar->lleft + 1 - start; |
|
start = ar->lleft + 1; |
|
} |
|
if (ar->pright && start + size - 1 >= ar->lright) |
|
size -= start + size - ar->lright; |
|
|
|
/* |
|
* Trim allocation request for filesystems with artificially small |
|
* groups. |
|
*/ |
|
if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) |
|
size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb); |
|
|
|
end = start + size; |
|
|
|
/* check we don't cross already preallocated blocks */ |
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
|
ext4_lblk_t pa_end; |
|
|
|
if (pa->pa_deleted) |
|
continue; |
|
spin_lock(&pa->pa_lock); |
|
if (pa->pa_deleted) { |
|
spin_unlock(&pa->pa_lock); |
|
continue; |
|
} |
|
|
|
pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), |
|
pa->pa_len); |
|
|
|
/* PA must not overlap original request */ |
|
BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || |
|
ac->ac_o_ex.fe_logical < pa->pa_lstart)); |
|
|
|
/* skip PAs this normalized request doesn't overlap with */ |
|
if (pa->pa_lstart >= end || pa_end <= start) { |
|
spin_unlock(&pa->pa_lock); |
|
continue; |
|
} |
|
BUG_ON(pa->pa_lstart <= start && pa_end >= end); |
|
|
|
/* adjust start or end to be adjacent to this pa */ |
|
if (pa_end <= ac->ac_o_ex.fe_logical) { |
|
BUG_ON(pa_end < start); |
|
start = pa_end; |
|
} else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) { |
|
BUG_ON(pa->pa_lstart > end); |
|
end = pa->pa_lstart; |
|
} |
|
spin_unlock(&pa->pa_lock); |
|
} |
|
rcu_read_unlock(); |
|
size = end - start; |
|
|
|
/* XXX: extra loop to check we really don't overlap preallocations */ |
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
|
ext4_lblk_t pa_end; |
|
|
|
spin_lock(&pa->pa_lock); |
|
if (pa->pa_deleted == 0) { |
|
pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), |
|
pa->pa_len); |
|
BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); |
|
} |
|
spin_unlock(&pa->pa_lock); |
|
} |
|
rcu_read_unlock(); |
|
|
|
if (start + size <= ac->ac_o_ex.fe_logical && |
|
start > ac->ac_o_ex.fe_logical) { |
|
ext4_msg(ac->ac_sb, KERN_ERR, |
|
"start %lu, size %lu, fe_logical %lu", |
|
(unsigned long) start, (unsigned long) size, |
|
(unsigned long) ac->ac_o_ex.fe_logical); |
|
BUG(); |
|
} |
|
BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
|
|
|
/* now prepare goal request */ |
|
|
|
/* XXX: is it better to align blocks WRT to logical |
|
* placement or satisfy big request as is */ |
|
ac->ac_g_ex.fe_logical = start; |
|
ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size); |
|
|
|
/* define goal start in order to merge */ |
|
if (ar->pright && (ar->lright == (start + size))) { |
|
/* merge to the right */ |
|
ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, |
|
&ac->ac_f_ex.fe_group, |
|
&ac->ac_f_ex.fe_start); |
|
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
|
} |
|
if (ar->pleft && (ar->lleft + 1 == start)) { |
|
/* merge to the left */ |
|
ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, |
|
&ac->ac_f_ex.fe_group, |
|
&ac->ac_f_ex.fe_start); |
|
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
|
} |
|
|
|
mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size, |
|
orig_size, start); |
|
} |
|
|
|
static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
|
|
if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) { |
|
atomic_inc(&sbi->s_bal_reqs); |
|
atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); |
|
if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) |
|
atomic_inc(&sbi->s_bal_success); |
|
atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); |
|
atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned); |
|
if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
|
ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
|
atomic_inc(&sbi->s_bal_goals); |
|
if (ac->ac_found > sbi->s_mb_max_to_scan) |
|
atomic_inc(&sbi->s_bal_breaks); |
|
} |
|
|
|
if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) |
|
trace_ext4_mballoc_alloc(ac); |
|
else |
|
trace_ext4_mballoc_prealloc(ac); |
|
} |
|
|
|
/* |
|
* Called on failure; free up any blocks from the inode PA for this |
|
* context. We don't need this for MB_GROUP_PA because we only change |
|
* pa_free in ext4_mb_release_context(), but on failure, we've already |
|
* zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed. |
|
*/ |
|
static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_prealloc_space *pa = ac->ac_pa; |
|
struct ext4_buddy e4b; |
|
int err; |
|
|
|
if (pa == NULL) { |
|
if (ac->ac_f_ex.fe_len == 0) |
|
return; |
|
err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b); |
|
if (err) { |
|
/* |
|
* This should never happen since we pin the |
|
* pages in the ext4_allocation_context so |
|
* ext4_mb_load_buddy() should never fail. |
|
*/ |
|
WARN(1, "mb_load_buddy failed (%d)", err); |
|
return; |
|
} |
|
ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group); |
|
mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start, |
|
ac->ac_f_ex.fe_len); |
|
ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group); |
|
ext4_mb_unload_buddy(&e4b); |
|
return; |
|
} |
|
if (pa->pa_type == MB_INODE_PA) |
|
pa->pa_free += ac->ac_b_ex.fe_len; |
|
} |
|
|
|
/* |
|
* use blocks preallocated to inode |
|
*/ |
|
static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, |
|
struct ext4_prealloc_space *pa) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
ext4_fsblk_t start; |
|
ext4_fsblk_t end; |
|
int len; |
|
|
|
/* found preallocated blocks, use them */ |
|
start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); |
|
end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len), |
|
start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len)); |
|
len = EXT4_NUM_B2C(sbi, end - start); |
|
ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, |
|
&ac->ac_b_ex.fe_start); |
|
ac->ac_b_ex.fe_len = len; |
|
ac->ac_status = AC_STATUS_FOUND; |
|
ac->ac_pa = pa; |
|
|
|
BUG_ON(start < pa->pa_pstart); |
|
BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len)); |
|
BUG_ON(pa->pa_free < len); |
|
pa->pa_free -= len; |
|
|
|
mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa); |
|
} |
|
|
|
/* |
|
* use blocks preallocated to locality group |
|
*/ |
|
static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, |
|
struct ext4_prealloc_space *pa) |
|
{ |
|
unsigned int len = ac->ac_o_ex.fe_len; |
|
|
|
ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, |
|
&ac->ac_b_ex.fe_group, |
|
&ac->ac_b_ex.fe_start); |
|
ac->ac_b_ex.fe_len = len; |
|
ac->ac_status = AC_STATUS_FOUND; |
|
ac->ac_pa = pa; |
|
|
|
/* we don't correct pa_pstart or pa_plen here to avoid |
|
* possible race when the group is being loaded concurrently |
|
* instead we correct pa later, after blocks are marked |
|
* in on-disk bitmap -- see ext4_mb_release_context() |
|
* Other CPUs are prevented from allocating from this pa by lg_mutex |
|
*/ |
|
mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n", |
|
pa->pa_lstart-len, len, pa); |
|
} |
|
|
|
/* |
|
* Return the prealloc space that have minimal distance |
|
* from the goal block. @cpa is the prealloc |
|
* space that is having currently known minimal distance |
|
* from the goal block. |
|
*/ |
|
static struct ext4_prealloc_space * |
|
ext4_mb_check_group_pa(ext4_fsblk_t goal_block, |
|
struct ext4_prealloc_space *pa, |
|
struct ext4_prealloc_space *cpa) |
|
{ |
|
ext4_fsblk_t cur_distance, new_distance; |
|
|
|
if (cpa == NULL) { |
|
atomic_inc(&pa->pa_count); |
|
return pa; |
|
} |
|
cur_distance = abs(goal_block - cpa->pa_pstart); |
|
new_distance = abs(goal_block - pa->pa_pstart); |
|
|
|
if (cur_distance <= new_distance) |
|
return cpa; |
|
|
|
/* drop the previous reference */ |
|
atomic_dec(&cpa->pa_count); |
|
atomic_inc(&pa->pa_count); |
|
return pa; |
|
} |
|
|
|
/* |
|
* search goal blocks in preallocated space |
|
*/ |
|
static noinline_for_stack bool |
|
ext4_mb_use_preallocated(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
int order, i; |
|
struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
|
struct ext4_locality_group *lg; |
|
struct ext4_prealloc_space *pa, *cpa = NULL; |
|
ext4_fsblk_t goal_block; |
|
|
|
/* only data can be preallocated */ |
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
|
return false; |
|
|
|
/* first, try per-file preallocation */ |
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
|
|
|
/* all fields in this condition don't change, |
|
* so we can skip locking for them */ |
|
if (ac->ac_o_ex.fe_logical < pa->pa_lstart || |
|
ac->ac_o_ex.fe_logical >= (pa->pa_lstart + |
|
EXT4_C2B(sbi, pa->pa_len))) |
|
continue; |
|
|
|
/* non-extent files can't have physical blocks past 2^32 */ |
|
if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) && |
|
(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) > |
|
EXT4_MAX_BLOCK_FILE_PHYS)) |
|
continue; |
|
|
|
/* found preallocated blocks, use them */ |
|
spin_lock(&pa->pa_lock); |
|
if (pa->pa_deleted == 0 && pa->pa_free) { |
|
atomic_inc(&pa->pa_count); |
|
ext4_mb_use_inode_pa(ac, pa); |
|
spin_unlock(&pa->pa_lock); |
|
ac->ac_criteria = 10; |
|
rcu_read_unlock(); |
|
return true; |
|
} |
|
spin_unlock(&pa->pa_lock); |
|
} |
|
rcu_read_unlock(); |
|
|
|
/* can we use group allocation? */ |
|
if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) |
|
return false; |
|
|
|
/* inode may have no locality group for some reason */ |
|
lg = ac->ac_lg; |
|
if (lg == NULL) |
|
return false; |
|
order = fls(ac->ac_o_ex.fe_len) - 1; |
|
if (order > PREALLOC_TB_SIZE - 1) |
|
/* The max size of hash table is PREALLOC_TB_SIZE */ |
|
order = PREALLOC_TB_SIZE - 1; |
|
|
|
goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex); |
|
/* |
|
* search for the prealloc space that is having |
|
* minimal distance from the goal block. |
|
*/ |
|
for (i = order; i < PREALLOC_TB_SIZE; i++) { |
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i], |
|
pa_inode_list) { |
|
spin_lock(&pa->pa_lock); |
|
if (pa->pa_deleted == 0 && |
|
pa->pa_free >= ac->ac_o_ex.fe_len) { |
|
|
|
cpa = ext4_mb_check_group_pa(goal_block, |
|
pa, cpa); |
|
} |
|
spin_unlock(&pa->pa_lock); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
if (cpa) { |
|
ext4_mb_use_group_pa(ac, cpa); |
|
ac->ac_criteria = 20; |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
/* |
|
* the function goes through all block freed in the group |
|
* but not yet committed and marks them used in in-core bitmap. |
|
* buddy must be generated from this bitmap |
|
* Need to be called with the ext4 group lock held |
|
*/ |
|
static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, |
|
ext4_group_t group) |
|
{ |
|
struct rb_node *n; |
|
struct ext4_group_info *grp; |
|
struct ext4_free_data *entry; |
|
|
|
grp = ext4_get_group_info(sb, group); |
|
n = rb_first(&(grp->bb_free_root)); |
|
|
|
while (n) { |
|
entry = rb_entry(n, struct ext4_free_data, efd_node); |
|
ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count); |
|
n = rb_next(n); |
|
} |
|
return; |
|
} |
|
|
|
/* |
|
* the function goes through all preallocation in this group and marks them |
|
* used in in-core bitmap. buddy must be generated from this bitmap |
|
* Need to be called with ext4 group lock held |
|
*/ |
|
static noinline_for_stack |
|
void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
|
ext4_group_t group) |
|
{ |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
|
struct ext4_prealloc_space *pa; |
|
struct list_head *cur; |
|
ext4_group_t groupnr; |
|
ext4_grpblk_t start; |
|
int preallocated = 0; |
|
int len; |
|
|
|
/* all form of preallocation discards first load group, |
|
* so the only competing code is preallocation use. |
|
* we don't need any locking here |
|
* notice we do NOT ignore preallocations with pa_deleted |
|
* otherwise we could leave used blocks available for |
|
* allocation in buddy when concurrent ext4_mb_put_pa() |
|
* is dropping preallocation |
|
*/ |
|
list_for_each(cur, &grp->bb_prealloc_list) { |
|
pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
|
spin_lock(&pa->pa_lock); |
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
|
&groupnr, &start); |
|
len = pa->pa_len; |
|
spin_unlock(&pa->pa_lock); |
|
if (unlikely(len == 0)) |
|
continue; |
|
BUG_ON(groupnr != group); |
|
ext4_set_bits(bitmap, start, len); |
|
preallocated += len; |
|
} |
|
mb_debug(sb, "preallocated %d for group %u\n", preallocated, group); |
|
} |
|
|
|
static void ext4_mb_mark_pa_deleted(struct super_block *sb, |
|
struct ext4_prealloc_space *pa) |
|
{ |
|
struct ext4_inode_info *ei; |
|
|
|
if (pa->pa_deleted) { |
|
ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n", |
|
pa->pa_type, pa->pa_pstart, pa->pa_lstart, |
|
pa->pa_len); |
|
return; |
|
} |
|
|
|
pa->pa_deleted = 1; |
|
|
|
if (pa->pa_type == MB_INODE_PA) { |
|
ei = EXT4_I(pa->pa_inode); |
|
atomic_dec(&ei->i_prealloc_active); |
|
} |
|
} |
|
|
|
static void ext4_mb_pa_callback(struct rcu_head *head) |
|
{ |
|
struct ext4_prealloc_space *pa; |
|
pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); |
|
|
|
BUG_ON(atomic_read(&pa->pa_count)); |
|
BUG_ON(pa->pa_deleted == 0); |
|
kmem_cache_free(ext4_pspace_cachep, pa); |
|
} |
|
|
|
/* |
|
* drops a reference to preallocated space descriptor |
|
* if this was the last reference and the space is consumed |
|
*/ |
|
static void ext4_mb_put_pa(struct ext4_allocation_context *ac, |
|
struct super_block *sb, struct ext4_prealloc_space *pa) |
|
{ |
|
ext4_group_t grp; |
|
ext4_fsblk_t grp_blk; |
|
|
|
/* in this short window concurrent discard can set pa_deleted */ |
|
spin_lock(&pa->pa_lock); |
|
if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) { |
|
spin_unlock(&pa->pa_lock); |
|
return; |
|
} |
|
|
|
if (pa->pa_deleted == 1) { |
|
spin_unlock(&pa->pa_lock); |
|
return; |
|
} |
|
|
|
ext4_mb_mark_pa_deleted(sb, pa); |
|
spin_unlock(&pa->pa_lock); |
|
|
|
grp_blk = pa->pa_pstart; |
|
/* |
|
* If doing group-based preallocation, pa_pstart may be in the |
|
* next group when pa is used up |
|
*/ |
|
if (pa->pa_type == MB_GROUP_PA) |
|
grp_blk--; |
|
|
|
grp = ext4_get_group_number(sb, grp_blk); |
|
|
|
/* |
|
* possible race: |
|
* |
|
* P1 (buddy init) P2 (regular allocation) |
|
* find block B in PA |
|
* copy on-disk bitmap to buddy |
|
* mark B in on-disk bitmap |
|
* drop PA from group |
|
* mark all PAs in buddy |
|
* |
|
* thus, P1 initializes buddy with B available. to prevent this |
|
* we make "copy" and "mark all PAs" atomic and serialize "drop PA" |
|
* against that pair |
|
*/ |
|
ext4_lock_group(sb, grp); |
|
list_del(&pa->pa_group_list); |
|
ext4_unlock_group(sb, grp); |
|
|
|
spin_lock(pa->pa_obj_lock); |
|
list_del_rcu(&pa->pa_inode_list); |
|
spin_unlock(pa->pa_obj_lock); |
|
|
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
|
} |
|
|
|
/* |
|
* creates new preallocated space for given inode |
|
*/ |
|
static noinline_for_stack void |
|
ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct ext4_prealloc_space *pa; |
|
struct ext4_group_info *grp; |
|
struct ext4_inode_info *ei; |
|
|
|
/* preallocate only when found space is larger then requested */ |
|
BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
|
BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
|
BUG_ON(ac->ac_pa == NULL); |
|
|
|
pa = ac->ac_pa; |
|
|
|
if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { |
|
int winl; |
|
int wins; |
|
int win; |
|
int offs; |
|
|
|
/* we can't allocate as much as normalizer wants. |
|
* so, found space must get proper lstart |
|
* to cover original request */ |
|
BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); |
|
BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); |
|
|
|
/* we're limited by original request in that |
|
* logical block must be covered any way |
|
* winl is window we can move our chunk within */ |
|
winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical; |
|
|
|
/* also, we should cover whole original request */ |
|
wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len); |
|
|
|
/* the smallest one defines real window */ |
|
win = min(winl, wins); |
|
|
|
offs = ac->ac_o_ex.fe_logical % |
|
EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
|
if (offs && offs < win) |
|
win = offs; |
|
|
|
ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - |
|
EXT4_NUM_B2C(sbi, win); |
|
BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); |
|
BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); |
|
} |
|
|
|
/* preallocation can change ac_b_ex, thus we store actually |
|
* allocated blocks for history */ |
|
ac->ac_f_ex = ac->ac_b_ex; |
|
|
|
pa->pa_lstart = ac->ac_b_ex.fe_logical; |
|
pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
|
pa->pa_len = ac->ac_b_ex.fe_len; |
|
pa->pa_free = pa->pa_len; |
|
spin_lock_init(&pa->pa_lock); |
|
INIT_LIST_HEAD(&pa->pa_inode_list); |
|
INIT_LIST_HEAD(&pa->pa_group_list); |
|
pa->pa_deleted = 0; |
|
pa->pa_type = MB_INODE_PA; |
|
|
|
mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, |
|
pa->pa_len, pa->pa_lstart); |
|
trace_ext4_mb_new_inode_pa(ac, pa); |
|
|
|
ext4_mb_use_inode_pa(ac, pa); |
|
atomic_add(pa->pa_free, &sbi->s_mb_preallocated); |
|
|
|
ei = EXT4_I(ac->ac_inode); |
|
grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
|
|
|
pa->pa_obj_lock = &ei->i_prealloc_lock; |
|
pa->pa_inode = ac->ac_inode; |
|
|
|
list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
|
|
|
spin_lock(pa->pa_obj_lock); |
|
list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list); |
|
spin_unlock(pa->pa_obj_lock); |
|
atomic_inc(&ei->i_prealloc_active); |
|
} |
|
|
|
/* |
|
* creates new preallocated space for locality group inodes belongs to |
|
*/ |
|
static noinline_for_stack void |
|
ext4_mb_new_group_pa(struct ext4_allocation_context *ac) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_locality_group *lg; |
|
struct ext4_prealloc_space *pa; |
|
struct ext4_group_info *grp; |
|
|
|
/* preallocate only when found space is larger then requested */ |
|
BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
|
BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
|
BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
|
BUG_ON(ac->ac_pa == NULL); |
|
|
|
pa = ac->ac_pa; |
|
|
|
/* preallocation can change ac_b_ex, thus we store actually |
|
* allocated blocks for history */ |
|
ac->ac_f_ex = ac->ac_b_ex; |
|
|
|
pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
|
pa->pa_lstart = pa->pa_pstart; |
|
pa->pa_len = ac->ac_b_ex.fe_len; |
|
pa->pa_free = pa->pa_len; |
|
spin_lock_init(&pa->pa_lock); |
|
INIT_LIST_HEAD(&pa->pa_inode_list); |
|
INIT_LIST_HEAD(&pa->pa_group_list); |
|
pa->pa_deleted = 0; |
|
pa->pa_type = MB_GROUP_PA; |
|
|
|
mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, |
|
pa->pa_len, pa->pa_lstart); |
|
trace_ext4_mb_new_group_pa(ac, pa); |
|
|
|
ext4_mb_use_group_pa(ac, pa); |
|
atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
|
|
|
grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
|
lg = ac->ac_lg; |
|
BUG_ON(lg == NULL); |
|
|
|
pa->pa_obj_lock = &lg->lg_prealloc_lock; |
|
pa->pa_inode = NULL; |
|
|
|
list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
|
|
|
/* |
|
* We will later add the new pa to the right bucket |
|
* after updating the pa_free in ext4_mb_release_context |
|
*/ |
|
} |
|
|
|
static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) |
|
{ |
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
|
ext4_mb_new_group_pa(ac); |
|
else |
|
ext4_mb_new_inode_pa(ac); |
|
} |
|
|
|
/* |
|
* finds all unused blocks in on-disk bitmap, frees them in |
|
* in-core bitmap and buddy. |
|
* @pa must be unlinked from inode and group lists, so that |
|
* nobody else can find/use it. |
|
* the caller MUST hold group/inode locks. |
|
* TODO: optimize the case when there are no in-core structures yet |
|
*/ |
|
static noinline_for_stack int |
|
ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, |
|
struct ext4_prealloc_space *pa) |
|
{ |
|
struct super_block *sb = e4b->bd_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
unsigned int end; |
|
unsigned int next; |
|
ext4_group_t group; |
|
ext4_grpblk_t bit; |
|
unsigned long long grp_blk_start; |
|
int free = 0; |
|
|
|
BUG_ON(pa->pa_deleted == 0); |
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
|
grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit); |
|
BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
|
end = bit + pa->pa_len; |
|
|
|
while (bit < end) { |
|
bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); |
|
if (bit >= end) |
|
break; |
|
next = mb_find_next_bit(bitmap_bh->b_data, end, bit); |
|
mb_debug(sb, "free preallocated %u/%u in group %u\n", |
|
(unsigned) ext4_group_first_block_no(sb, group) + bit, |
|
(unsigned) next - bit, (unsigned) group); |
|
free += next - bit; |
|
|
|
trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit); |
|
trace_ext4_mb_release_inode_pa(pa, (grp_blk_start + |
|
EXT4_C2B(sbi, bit)), |
|
next - bit); |
|
mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); |
|
bit = next + 1; |
|
} |
|
if (free != pa->pa_free) { |
|
ext4_msg(e4b->bd_sb, KERN_CRIT, |
|
"pa %p: logic %lu, phys. %lu, len %d", |
|
pa, (unsigned long) pa->pa_lstart, |
|
(unsigned long) pa->pa_pstart, |
|
pa->pa_len); |
|
ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u", |
|
free, pa->pa_free); |
|
/* |
|
* pa is already deleted so we use the value obtained |
|
* from the bitmap and continue. |
|
*/ |
|
} |
|
atomic_add(free, &sbi->s_mb_discarded); |
|
|
|
return 0; |
|
} |
|
|
|
static noinline_for_stack int |
|
ext4_mb_release_group_pa(struct ext4_buddy *e4b, |
|
struct ext4_prealloc_space *pa) |
|
{ |
|
struct super_block *sb = e4b->bd_sb; |
|
ext4_group_t group; |
|
ext4_grpblk_t bit; |
|
|
|
trace_ext4_mb_release_group_pa(sb, pa); |
|
BUG_ON(pa->pa_deleted == 0); |
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
|
BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
|
mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); |
|
atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); |
|
trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* releases all preallocations in given group |
|
* |
|
* first, we need to decide discard policy: |
|
* - when do we discard |
|
* 1) ENOSPC |
|
* - how many do we discard |
|
* 1) how many requested |
|
*/ |
|
static noinline_for_stack int |
|
ext4_mb_discard_group_preallocations(struct super_block *sb, |
|
ext4_group_t group, int needed) |
|
{ |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct ext4_prealloc_space *pa, *tmp; |
|
struct list_head list; |
|
struct ext4_buddy e4b; |
|
int err; |
|
int busy = 0; |
|
int free, free_total = 0; |
|
|
|
mb_debug(sb, "discard preallocation for group %u\n", group); |
|
if (list_empty(&grp->bb_prealloc_list)) |
|
goto out_dbg; |
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
ext4_error_err(sb, -err, |
|
"Error %d reading block bitmap for %u", |
|
err, group); |
|
goto out_dbg; |
|
} |
|
|
|
err = ext4_mb_load_buddy(sb, group, &e4b); |
|
if (err) { |
|
ext4_warning(sb, "Error %d loading buddy information for %u", |
|
err, group); |
|
put_bh(bitmap_bh); |
|
goto out_dbg; |
|
} |
|
|
|
if (needed == 0) |
|
needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; |
|
|
|
INIT_LIST_HEAD(&list); |
|
repeat: |
|
free = 0; |
|
ext4_lock_group(sb, group); |
|
list_for_each_entry_safe(pa, tmp, |
|
&grp->bb_prealloc_list, pa_group_list) { |
|
spin_lock(&pa->pa_lock); |
|
if (atomic_read(&pa->pa_count)) { |
|
spin_unlock(&pa->pa_lock); |
|
busy = 1; |
|
continue; |
|
} |
|
if (pa->pa_deleted) { |
|
spin_unlock(&pa->pa_lock); |
|
continue; |
|
} |
|
|
|
/* seems this one can be freed ... */ |
|
ext4_mb_mark_pa_deleted(sb, pa); |
|
|
|
if (!free) |
|
this_cpu_inc(discard_pa_seq); |
|
|
|
/* we can trust pa_free ... */ |
|
free += pa->pa_free; |
|
|
|
spin_unlock(&pa->pa_lock); |
|
|
|
list_del(&pa->pa_group_list); |
|
list_add(&pa->u.pa_tmp_list, &list); |
|
} |
|
|
|
/* now free all selected PAs */ |
|
list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
|
|
|
/* remove from object (inode or locality group) */ |
|
spin_lock(pa->pa_obj_lock); |
|
list_del_rcu(&pa->pa_inode_list); |
|
spin_unlock(pa->pa_obj_lock); |
|
|
|
if (pa->pa_type == MB_GROUP_PA) |
|
ext4_mb_release_group_pa(&e4b, pa); |
|
else |
|
ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
|
|
|
list_del(&pa->u.pa_tmp_list); |
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
|
} |
|
|
|
free_total += free; |
|
|
|
/* if we still need more blocks and some PAs were used, try again */ |
|
if (free_total < needed && busy) { |
|
ext4_unlock_group(sb, group); |
|
cond_resched(); |
|
busy = 0; |
|
goto repeat; |
|
} |
|
ext4_unlock_group(sb, group); |
|
ext4_mb_unload_buddy(&e4b); |
|
put_bh(bitmap_bh); |
|
out_dbg: |
|
mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n", |
|
free_total, group, grp->bb_free); |
|
return free_total; |
|
} |
|
|
|
/* |
|
* releases all non-used preallocated blocks for given inode |
|
* |
|
* It's important to discard preallocations under i_data_sem |
|
* We don't want another block to be served from the prealloc |
|
* space when we are discarding the inode prealloc space. |
|
* |
|
* FIXME!! Make sure it is valid at all the call sites |
|
*/ |
|
void ext4_discard_preallocations(struct inode *inode, unsigned int needed) |
|
{ |
|
struct ext4_inode_info *ei = EXT4_I(inode); |
|
struct super_block *sb = inode->i_sb; |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct ext4_prealloc_space *pa, *tmp; |
|
ext4_group_t group = 0; |
|
struct list_head list; |
|
struct ext4_buddy e4b; |
|
int err; |
|
|
|
if (!S_ISREG(inode->i_mode)) { |
|
/*BUG_ON(!list_empty(&ei->i_prealloc_list));*/ |
|
return; |
|
} |
|
|
|
if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) |
|
return; |
|
|
|
mb_debug(sb, "discard preallocation for inode %lu\n", |
|
inode->i_ino); |
|
trace_ext4_discard_preallocations(inode, |
|
atomic_read(&ei->i_prealloc_active), needed); |
|
|
|
INIT_LIST_HEAD(&list); |
|
|
|
if (needed == 0) |
|
needed = UINT_MAX; |
|
|
|
repeat: |
|
/* first, collect all pa's in the inode */ |
|
spin_lock(&ei->i_prealloc_lock); |
|
while (!list_empty(&ei->i_prealloc_list) && needed) { |
|
pa = list_entry(ei->i_prealloc_list.prev, |
|
struct ext4_prealloc_space, pa_inode_list); |
|
BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); |
|
spin_lock(&pa->pa_lock); |
|
if (atomic_read(&pa->pa_count)) { |
|
/* this shouldn't happen often - nobody should |
|
* use preallocation while we're discarding it */ |
|
spin_unlock(&pa->pa_lock); |
|
spin_unlock(&ei->i_prealloc_lock); |
|
ext4_msg(sb, KERN_ERR, |
|
"uh-oh! used pa while discarding"); |
|
WARN_ON(1); |
|
schedule_timeout_uninterruptible(HZ); |
|
goto repeat; |
|
|
|
} |
|
if (pa->pa_deleted == 0) { |
|
ext4_mb_mark_pa_deleted(sb, pa); |
|
spin_unlock(&pa->pa_lock); |
|
list_del_rcu(&pa->pa_inode_list); |
|
list_add(&pa->u.pa_tmp_list, &list); |
|
needed--; |
|
continue; |
|
} |
|
|
|
/* someone is deleting pa right now */ |
|
spin_unlock(&pa->pa_lock); |
|
spin_unlock(&ei->i_prealloc_lock); |
|
|
|
/* we have to wait here because pa_deleted |
|
* doesn't mean pa is already unlinked from |
|
* the list. as we might be called from |
|
* ->clear_inode() the inode will get freed |
|
* and concurrent thread which is unlinking |
|
* pa from inode's list may access already |
|
* freed memory, bad-bad-bad */ |
|
|
|
/* XXX: if this happens too often, we can |
|
* add a flag to force wait only in case |
|
* of ->clear_inode(), but not in case of |
|
* regular truncate */ |
|
schedule_timeout_uninterruptible(HZ); |
|
goto repeat; |
|
} |
|
spin_unlock(&ei->i_prealloc_lock); |
|
|
|
list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
|
BUG_ON(pa->pa_type != MB_INODE_PA); |
|
group = ext4_get_group_number(sb, pa->pa_pstart); |
|
|
|
err = ext4_mb_load_buddy_gfp(sb, group, &e4b, |
|
GFP_NOFS|__GFP_NOFAIL); |
|
if (err) { |
|
ext4_error_err(sb, -err, "Error %d loading buddy information for %u", |
|
err, group); |
|
continue; |
|
} |
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
ext4_error_err(sb, -err, "Error %d reading block bitmap for %u", |
|
err, group); |
|
ext4_mb_unload_buddy(&e4b); |
|
continue; |
|
} |
|
|
|
ext4_lock_group(sb, group); |
|
list_del(&pa->pa_group_list); |
|
ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
|
ext4_unlock_group(sb, group); |
|
|
|
ext4_mb_unload_buddy(&e4b); |
|
put_bh(bitmap_bh); |
|
|
|
list_del(&pa->u.pa_tmp_list); |
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
|
} |
|
} |
|
|
|
static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_prealloc_space *pa; |
|
|
|
BUG_ON(ext4_pspace_cachep == NULL); |
|
pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS); |
|
if (!pa) |
|
return -ENOMEM; |
|
atomic_set(&pa->pa_count, 1); |
|
ac->ac_pa = pa; |
|
return 0; |
|
} |
|
|
|
static void ext4_mb_pa_free(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_prealloc_space *pa = ac->ac_pa; |
|
|
|
BUG_ON(!pa); |
|
ac->ac_pa = NULL; |
|
WARN_ON(!atomic_dec_and_test(&pa->pa_count)); |
|
kmem_cache_free(ext4_pspace_cachep, pa); |
|
} |
|
|
|
#ifdef CONFIG_EXT4_DEBUG |
|
static inline void ext4_mb_show_pa(struct super_block *sb) |
|
{ |
|
ext4_group_t i, ngroups; |
|
|
|
if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) |
|
return; |
|
|
|
ngroups = ext4_get_groups_count(sb); |
|
mb_debug(sb, "groups: "); |
|
for (i = 0; i < ngroups; i++) { |
|
struct ext4_group_info *grp = ext4_get_group_info(sb, i); |
|
struct ext4_prealloc_space *pa; |
|
ext4_grpblk_t start; |
|
struct list_head *cur; |
|
ext4_lock_group(sb, i); |
|
list_for_each(cur, &grp->bb_prealloc_list) { |
|
pa = list_entry(cur, struct ext4_prealloc_space, |
|
pa_group_list); |
|
spin_lock(&pa->pa_lock); |
|
ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
|
NULL, &start); |
|
spin_unlock(&pa->pa_lock); |
|
mb_debug(sb, "PA:%u:%d:%d\n", i, start, |
|
pa->pa_len); |
|
} |
|
ext4_unlock_group(sb, i); |
|
mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free, |
|
grp->bb_fragments); |
|
} |
|
} |
|
|
|
static void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
|
{ |
|
struct super_block *sb = ac->ac_sb; |
|
|
|
if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) |
|
return; |
|
|
|
mb_debug(sb, "Can't allocate:" |
|
" Allocation context details:"); |
|
mb_debug(sb, "status %u flags 0x%x", |
|
ac->ac_status, ac->ac_flags); |
|
mb_debug(sb, "orig %lu/%lu/%lu@%lu, " |
|
"goal %lu/%lu/%lu@%lu, " |
|
"best %lu/%lu/%lu@%lu cr %d", |
|
(unsigned long)ac->ac_o_ex.fe_group, |
|
(unsigned long)ac->ac_o_ex.fe_start, |
|
(unsigned long)ac->ac_o_ex.fe_len, |
|
(unsigned long)ac->ac_o_ex.fe_logical, |
|
(unsigned long)ac->ac_g_ex.fe_group, |
|
(unsigned long)ac->ac_g_ex.fe_start, |
|
(unsigned long)ac->ac_g_ex.fe_len, |
|
(unsigned long)ac->ac_g_ex.fe_logical, |
|
(unsigned long)ac->ac_b_ex.fe_group, |
|
(unsigned long)ac->ac_b_ex.fe_start, |
|
(unsigned long)ac->ac_b_ex.fe_len, |
|
(unsigned long)ac->ac_b_ex.fe_logical, |
|
(int)ac->ac_criteria); |
|
mb_debug(sb, "%u found", ac->ac_found); |
|
ext4_mb_show_pa(sb); |
|
} |
|
#else |
|
static inline void ext4_mb_show_pa(struct super_block *sb) |
|
{ |
|
return; |
|
} |
|
static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
|
{ |
|
ext4_mb_show_pa(ac->ac_sb); |
|
return; |
|
} |
|
#endif |
|
|
|
/* |
|
* We use locality group preallocation for small size file. The size of the |
|
* file is determined by the current size or the resulting size after |
|
* allocation which ever is larger |
|
* |
|
* One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req |
|
*/ |
|
static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) |
|
{ |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
int bsbits = ac->ac_sb->s_blocksize_bits; |
|
loff_t size, isize; |
|
|
|
if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
|
return; |
|
|
|
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
|
return; |
|
|
|
size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); |
|
isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) |
|
>> bsbits; |
|
|
|
if ((size == isize) && !ext4_fs_is_busy(sbi) && |
|
!inode_is_open_for_write(ac->ac_inode)) { |
|
ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; |
|
return; |
|
} |
|
|
|
if (sbi->s_mb_group_prealloc <= 0) { |
|
ac->ac_flags |= EXT4_MB_STREAM_ALLOC; |
|
return; |
|
} |
|
|
|
/* don't use group allocation for large files */ |
|
size = max(size, isize); |
|
if (size > sbi->s_mb_stream_request) { |
|
ac->ac_flags |= EXT4_MB_STREAM_ALLOC; |
|
return; |
|
} |
|
|
|
BUG_ON(ac->ac_lg != NULL); |
|
/* |
|
* locality group prealloc space are per cpu. The reason for having |
|
* per cpu locality group is to reduce the contention between block |
|
* request from multiple CPUs. |
|
*/ |
|
ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups); |
|
|
|
/* we're going to use group allocation */ |
|
ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; |
|
|
|
/* serialize all allocations in the group */ |
|
mutex_lock(&ac->ac_lg->lg_mutex); |
|
} |
|
|
|
static noinline_for_stack int |
|
ext4_mb_initialize_context(struct ext4_allocation_context *ac, |
|
struct ext4_allocation_request *ar) |
|
{ |
|
struct super_block *sb = ar->inode->i_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct ext4_super_block *es = sbi->s_es; |
|
ext4_group_t group; |
|
unsigned int len; |
|
ext4_fsblk_t goal; |
|
ext4_grpblk_t block; |
|
|
|
/* we can't allocate > group size */ |
|
len = ar->len; |
|
|
|
/* just a dirty hack to filter too big requests */ |
|
if (len >= EXT4_CLUSTERS_PER_GROUP(sb)) |
|
len = EXT4_CLUSTERS_PER_GROUP(sb); |
|
|
|
/* start searching from the goal */ |
|
goal = ar->goal; |
|
if (goal < le32_to_cpu(es->s_first_data_block) || |
|
goal >= ext4_blocks_count(es)) |
|
goal = le32_to_cpu(es->s_first_data_block); |
|
ext4_get_group_no_and_offset(sb, goal, &group, &block); |
|
|
|
/* set up allocation goals */ |
|
ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical); |
|
ac->ac_status = AC_STATUS_CONTINUE; |
|
ac->ac_sb = sb; |
|
ac->ac_inode = ar->inode; |
|
ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical; |
|
ac->ac_o_ex.fe_group = group; |
|
ac->ac_o_ex.fe_start = block; |
|
ac->ac_o_ex.fe_len = len; |
|
ac->ac_g_ex = ac->ac_o_ex; |
|
ac->ac_flags = ar->flags; |
|
|
|
/* we have to define context: we'll work with a file or |
|
* locality group. this is a policy, actually */ |
|
ext4_mb_group_or_file(ac); |
|
|
|
mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, " |
|
"left: %u/%u, right %u/%u to %swritable\n", |
|
(unsigned) ar->len, (unsigned) ar->logical, |
|
(unsigned) ar->goal, ac->ac_flags, ac->ac_2order, |
|
(unsigned) ar->lleft, (unsigned) ar->pleft, |
|
(unsigned) ar->lright, (unsigned) ar->pright, |
|
inode_is_open_for_write(ar->inode) ? "" : "non-"); |
|
return 0; |
|
|
|
} |
|
|
|
static noinline_for_stack void |
|
ext4_mb_discard_lg_preallocations(struct super_block *sb, |
|
struct ext4_locality_group *lg, |
|
int order, int total_entries) |
|
{ |
|
ext4_group_t group = 0; |
|
struct ext4_buddy e4b; |
|
struct list_head discard_list; |
|
struct ext4_prealloc_space *pa, *tmp; |
|
|
|
mb_debug(sb, "discard locality group preallocation\n"); |
|
|
|
INIT_LIST_HEAD(&discard_list); |
|
|
|
spin_lock(&lg->lg_prealloc_lock); |
|
list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order], |
|
pa_inode_list, |
|
lockdep_is_held(&lg->lg_prealloc_lock)) { |
|
spin_lock(&pa->pa_lock); |
|
if (atomic_read(&pa->pa_count)) { |
|
/* |
|
* This is the pa that we just used |
|
* for block allocation. So don't |
|
* free that |
|
*/ |
|
spin_unlock(&pa->pa_lock); |
|
continue; |
|
} |
|
if (pa->pa_deleted) { |
|
spin_unlock(&pa->pa_lock); |
|
continue; |
|
} |
|
/* only lg prealloc space */ |
|
BUG_ON(pa->pa_type != MB_GROUP_PA); |
|
|
|
/* seems this one can be freed ... */ |
|
ext4_mb_mark_pa_deleted(sb, pa); |
|
spin_unlock(&pa->pa_lock); |
|
|
|
list_del_rcu(&pa->pa_inode_list); |
|
list_add(&pa->u.pa_tmp_list, &discard_list); |
|
|
|
total_entries--; |
|
if (total_entries <= 5) { |
|
/* |
|
* we want to keep only 5 entries |
|
* allowing it to grow to 8. This |
|
* mak sure we don't call discard |
|
* soon for this list. |
|
*/ |
|
break; |
|
} |
|
} |
|
spin_unlock(&lg->lg_prealloc_lock); |
|
|
|
list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { |
|
int err; |
|
|
|
group = ext4_get_group_number(sb, pa->pa_pstart); |
|
err = ext4_mb_load_buddy_gfp(sb, group, &e4b, |
|
GFP_NOFS|__GFP_NOFAIL); |
|
if (err) { |
|
ext4_error_err(sb, -err, "Error %d loading buddy information for %u", |
|
err, group); |
|
continue; |
|
} |
|
ext4_lock_group(sb, group); |
|
list_del(&pa->pa_group_list); |
|
ext4_mb_release_group_pa(&e4b, pa); |
|
ext4_unlock_group(sb, group); |
|
|
|
ext4_mb_unload_buddy(&e4b); |
|
list_del(&pa->u.pa_tmp_list); |
|
call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
|
} |
|
} |
|
|
|
/* |
|
* We have incremented pa_count. So it cannot be freed at this |
|
* point. Also we hold lg_mutex. So no parallel allocation is |
|
* possible from this lg. That means pa_free cannot be updated. |
|
* |
|
* A parallel ext4_mb_discard_group_preallocations is possible. |
|
* which can cause the lg_prealloc_list to be updated. |
|
*/ |
|
|
|
static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) |
|
{ |
|
int order, added = 0, lg_prealloc_count = 1; |
|
struct super_block *sb = ac->ac_sb; |
|
struct ext4_locality_group *lg = ac->ac_lg; |
|
struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa; |
|
|
|
order = fls(pa->pa_free) - 1; |
|
if (order > PREALLOC_TB_SIZE - 1) |
|
/* The max size of hash table is PREALLOC_TB_SIZE */ |
|
order = PREALLOC_TB_SIZE - 1; |
|
/* Add the prealloc space to lg */ |
|
spin_lock(&lg->lg_prealloc_lock); |
|
list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], |
|
pa_inode_list, |
|
lockdep_is_held(&lg->lg_prealloc_lock)) { |
|
spin_lock(&tmp_pa->pa_lock); |
|
if (tmp_pa->pa_deleted) { |
|
spin_unlock(&tmp_pa->pa_lock); |
|
continue; |
|
} |
|
if (!added && pa->pa_free < tmp_pa->pa_free) { |
|
/* Add to the tail of the previous entry */ |
|
list_add_tail_rcu(&pa->pa_inode_list, |
|
&tmp_pa->pa_inode_list); |
|
added = 1; |
|
/* |
|
* we want to count the total |
|
* number of entries in the list |
|
*/ |
|
} |
|
spin_unlock(&tmp_pa->pa_lock); |
|
lg_prealloc_count++; |
|
} |
|
if (!added) |
|
list_add_tail_rcu(&pa->pa_inode_list, |
|
&lg->lg_prealloc_list[order]); |
|
spin_unlock(&lg->lg_prealloc_lock); |
|
|
|
/* Now trim the list to be not more than 8 elements */ |
|
if (lg_prealloc_count > 8) { |
|
ext4_mb_discard_lg_preallocations(sb, lg, |
|
order, lg_prealloc_count); |
|
return; |
|
} |
|
return ; |
|
} |
|
|
|
/* |
|
* if per-inode prealloc list is too long, trim some PA |
|
*/ |
|
static void ext4_mb_trim_inode_pa(struct inode *inode) |
|
{ |
|
struct ext4_inode_info *ei = EXT4_I(inode); |
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
|
int count, delta; |
|
|
|
count = atomic_read(&ei->i_prealloc_active); |
|
delta = (sbi->s_mb_max_inode_prealloc >> 2) + 1; |
|
if (count > sbi->s_mb_max_inode_prealloc + delta) { |
|
count -= sbi->s_mb_max_inode_prealloc; |
|
ext4_discard_preallocations(inode, count); |
|
} |
|
} |
|
|
|
/* |
|
* release all resource we used in allocation |
|
*/ |
|
static int ext4_mb_release_context(struct ext4_allocation_context *ac) |
|
{ |
|
struct inode *inode = ac->ac_inode; |
|
struct ext4_inode_info *ei = EXT4_I(inode); |
|
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
|
struct ext4_prealloc_space *pa = ac->ac_pa; |
|
if (pa) { |
|
if (pa->pa_type == MB_GROUP_PA) { |
|
/* see comment in ext4_mb_use_group_pa() */ |
|
spin_lock(&pa->pa_lock); |
|
pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
|
pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
|
pa->pa_free -= ac->ac_b_ex.fe_len; |
|
pa->pa_len -= ac->ac_b_ex.fe_len; |
|
spin_unlock(&pa->pa_lock); |
|
|
|
/* |
|
* We want to add the pa to the right bucket. |
|
* Remove it from the list and while adding |
|
* make sure the list to which we are adding |
|
* doesn't grow big. |
|
*/ |
|
if (likely(pa->pa_free)) { |
|
spin_lock(pa->pa_obj_lock); |
|
list_del_rcu(&pa->pa_inode_list); |
|
spin_unlock(pa->pa_obj_lock); |
|
ext4_mb_add_n_trim(ac); |
|
} |
|
} |
|
|
|
if (pa->pa_type == MB_INODE_PA) { |
|
/* |
|
* treat per-inode prealloc list as a lru list, then try |
|
* to trim the least recently used PA. |
|
*/ |
|
spin_lock(pa->pa_obj_lock); |
|
list_move(&pa->pa_inode_list, &ei->i_prealloc_list); |
|
spin_unlock(pa->pa_obj_lock); |
|
} |
|
|
|
ext4_mb_put_pa(ac, ac->ac_sb, pa); |
|
} |
|
if (ac->ac_bitmap_page) |
|
put_page(ac->ac_bitmap_page); |
|
if (ac->ac_buddy_page) |
|
put_page(ac->ac_buddy_page); |
|
if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
|
mutex_unlock(&ac->ac_lg->lg_mutex); |
|
ext4_mb_collect_stats(ac); |
|
ext4_mb_trim_inode_pa(inode); |
|
return 0; |
|
} |
|
|
|
static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) |
|
{ |
|
ext4_group_t i, ngroups = ext4_get_groups_count(sb); |
|
int ret; |
|
int freed = 0; |
|
|
|
trace_ext4_mb_discard_preallocations(sb, needed); |
|
for (i = 0; i < ngroups && needed > 0; i++) { |
|
ret = ext4_mb_discard_group_preallocations(sb, i, needed); |
|
freed += ret; |
|
needed -= ret; |
|
} |
|
|
|
return freed; |
|
} |
|
|
|
static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb, |
|
struct ext4_allocation_context *ac, u64 *seq) |
|
{ |
|
int freed; |
|
u64 seq_retry = 0; |
|
bool ret = false; |
|
|
|
freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); |
|
if (freed) { |
|
ret = true; |
|
goto out_dbg; |
|
} |
|
seq_retry = ext4_get_discard_pa_seq_sum(); |
|
if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) { |
|
ac->ac_flags |= EXT4_MB_STRICT_CHECK; |
|
*seq = seq_retry; |
|
ret = true; |
|
} |
|
|
|
out_dbg: |
|
mb_debug(sb, "freed %d, retry ? %s\n", freed, ret ? "yes" : "no"); |
|
return ret; |
|
} |
|
|
|
static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, |
|
struct ext4_allocation_request *ar, int *errp); |
|
|
|
/* |
|
* Main entry point into mballoc to allocate blocks |
|
* it tries to use preallocation first, then falls back |
|
* to usual allocation |
|
*/ |
|
ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, |
|
struct ext4_allocation_request *ar, int *errp) |
|
{ |
|
struct ext4_allocation_context *ac = NULL; |
|
struct ext4_sb_info *sbi; |
|
struct super_block *sb; |
|
ext4_fsblk_t block = 0; |
|
unsigned int inquota = 0; |
|
unsigned int reserv_clstrs = 0; |
|
u64 seq; |
|
|
|
might_sleep(); |
|
sb = ar->inode->i_sb; |
|
sbi = EXT4_SB(sb); |
|
|
|
trace_ext4_request_blocks(ar); |
|
if (sbi->s_mount_state & EXT4_FC_REPLAY) |
|
return ext4_mb_new_blocks_simple(handle, ar, errp); |
|
|
|
/* Allow to use superuser reservation for quota file */ |
|
if (ext4_is_quota_file(ar->inode)) |
|
ar->flags |= EXT4_MB_USE_ROOT_BLOCKS; |
|
|
|
if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) { |
|
/* Without delayed allocation we need to verify |
|
* there is enough free blocks to do block allocation |
|
* and verify allocation doesn't exceed the quota limits. |
|
*/ |
|
while (ar->len && |
|
ext4_claim_free_clusters(sbi, ar->len, ar->flags)) { |
|
|
|
/* let others to free the space */ |
|
cond_resched(); |
|
ar->len = ar->len >> 1; |
|
} |
|
if (!ar->len) { |
|
ext4_mb_show_pa(sb); |
|
*errp = -ENOSPC; |
|
return 0; |
|
} |
|
reserv_clstrs = ar->len; |
|
if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) { |
|
dquot_alloc_block_nofail(ar->inode, |
|
EXT4_C2B(sbi, ar->len)); |
|
} else { |
|
while (ar->len && |
|
dquot_alloc_block(ar->inode, |
|
EXT4_C2B(sbi, ar->len))) { |
|
|
|
ar->flags |= EXT4_MB_HINT_NOPREALLOC; |
|
ar->len--; |
|
} |
|
} |
|
inquota = ar->len; |
|
if (ar->len == 0) { |
|
*errp = -EDQUOT; |
|
goto out; |
|
} |
|
} |
|
|
|
ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS); |
|
if (!ac) { |
|
ar->len = 0; |
|
*errp = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
*errp = ext4_mb_initialize_context(ac, ar); |
|
if (*errp) { |
|
ar->len = 0; |
|
goto out; |
|
} |
|
|
|
ac->ac_op = EXT4_MB_HISTORY_PREALLOC; |
|
seq = this_cpu_read(discard_pa_seq); |
|
if (!ext4_mb_use_preallocated(ac)) { |
|
ac->ac_op = EXT4_MB_HISTORY_ALLOC; |
|
ext4_mb_normalize_request(ac, ar); |
|
|
|
*errp = ext4_mb_pa_alloc(ac); |
|
if (*errp) |
|
goto errout; |
|
repeat: |
|
/* allocate space in core */ |
|
*errp = ext4_mb_regular_allocator(ac); |
|
/* |
|
* pa allocated above is added to grp->bb_prealloc_list only |
|
* when we were able to allocate some block i.e. when |
|
* ac->ac_status == AC_STATUS_FOUND. |
|
* And error from above mean ac->ac_status != AC_STATUS_FOUND |
|
* So we have to free this pa here itself. |
|
*/ |
|
if (*errp) { |
|
ext4_mb_pa_free(ac); |
|
ext4_discard_allocated_blocks(ac); |
|
goto errout; |
|
} |
|
if (ac->ac_status == AC_STATUS_FOUND && |
|
ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len) |
|
ext4_mb_pa_free(ac); |
|
} |
|
if (likely(ac->ac_status == AC_STATUS_FOUND)) { |
|
*errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); |
|
if (*errp) { |
|
ext4_discard_allocated_blocks(ac); |
|
goto errout; |
|
} else { |
|
block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
|
ar->len = ac->ac_b_ex.fe_len; |
|
} |
|
} else { |
|
if (ext4_mb_discard_preallocations_should_retry(sb, ac, &seq)) |
|
goto repeat; |
|
/* |
|
* If block allocation fails then the pa allocated above |
|
* needs to be freed here itself. |
|
*/ |
|
ext4_mb_pa_free(ac); |
|
*errp = -ENOSPC; |
|
} |
|
|
|
errout: |
|
if (*errp) { |
|
ac->ac_b_ex.fe_len = 0; |
|
ar->len = 0; |
|
ext4_mb_show_ac(ac); |
|
} |
|
ext4_mb_release_context(ac); |
|
out: |
|
if (ac) |
|
kmem_cache_free(ext4_ac_cachep, ac); |
|
if (inquota && ar->len < inquota) |
|
dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); |
|
if (!ar->len) { |
|
if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) |
|
/* release all the reserved blocks if non delalloc */ |
|
percpu_counter_sub(&sbi->s_dirtyclusters_counter, |
|
reserv_clstrs); |
|
} |
|
|
|
trace_ext4_allocate_blocks(ar, (unsigned long long)block); |
|
|
|
return block; |
|
} |
|
|
|
/* |
|
* We can merge two free data extents only if the physical blocks |
|
* are contiguous, AND the extents were freed by the same transaction, |
|
* AND the blocks are associated with the same group. |
|
*/ |
|
static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi, |
|
struct ext4_free_data *entry, |
|
struct ext4_free_data *new_entry, |
|
struct rb_root *entry_rb_root) |
|
{ |
|
if ((entry->efd_tid != new_entry->efd_tid) || |
|
(entry->efd_group != new_entry->efd_group)) |
|
return; |
|
if (entry->efd_start_cluster + entry->efd_count == |
|
new_entry->efd_start_cluster) { |
|
new_entry->efd_start_cluster = entry->efd_start_cluster; |
|
new_entry->efd_count += entry->efd_count; |
|
} else if (new_entry->efd_start_cluster + new_entry->efd_count == |
|
entry->efd_start_cluster) { |
|
new_entry->efd_count += entry->efd_count; |
|
} else |
|
return; |
|
spin_lock(&sbi->s_md_lock); |
|
list_del(&entry->efd_list); |
|
spin_unlock(&sbi->s_md_lock); |
|
rb_erase(&entry->efd_node, entry_rb_root); |
|
kmem_cache_free(ext4_free_data_cachep, entry); |
|
} |
|
|
|
static noinline_for_stack int |
|
ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, |
|
struct ext4_free_data *new_entry) |
|
{ |
|
ext4_group_t group = e4b->bd_group; |
|
ext4_grpblk_t cluster; |
|
ext4_grpblk_t clusters = new_entry->efd_count; |
|
struct ext4_free_data *entry; |
|
struct ext4_group_info *db = e4b->bd_info; |
|
struct super_block *sb = e4b->bd_sb; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct rb_node **n = &db->bb_free_root.rb_node, *node; |
|
struct rb_node *parent = NULL, *new_node; |
|
|
|
BUG_ON(!ext4_handle_valid(handle)); |
|
BUG_ON(e4b->bd_bitmap_page == NULL); |
|
BUG_ON(e4b->bd_buddy_page == NULL); |
|
|
|
new_node = &new_entry->efd_node; |
|
cluster = new_entry->efd_start_cluster; |
|
|
|
if (!*n) { |
|
/* first free block exent. We need to |
|
protect buddy cache from being freed, |
|
* otherwise we'll refresh it from |
|
* on-disk bitmap and lose not-yet-available |
|
* blocks */ |
|
get_page(e4b->bd_buddy_page); |
|
get_page(e4b->bd_bitmap_page); |
|
} |
|
while (*n) { |
|
parent = *n; |
|
entry = rb_entry(parent, struct ext4_free_data, efd_node); |
|
if (cluster < entry->efd_start_cluster) |
|
n = &(*n)->rb_left; |
|
else if (cluster >= (entry->efd_start_cluster + entry->efd_count)) |
|
n = &(*n)->rb_right; |
|
else { |
|
ext4_grp_locked_error(sb, group, 0, |
|
ext4_group_first_block_no(sb, group) + |
|
EXT4_C2B(sbi, cluster), |
|
"Block already on to-be-freed list"); |
|
kmem_cache_free(ext4_free_data_cachep, new_entry); |
|
return 0; |
|
} |
|
} |
|
|
|
rb_link_node(new_node, parent, n); |
|
rb_insert_color(new_node, &db->bb_free_root); |
|
|
|
/* Now try to see the extent can be merged to left and right */ |
|
node = rb_prev(new_node); |
|
if (node) { |
|
entry = rb_entry(node, struct ext4_free_data, efd_node); |
|
ext4_try_merge_freed_extent(sbi, entry, new_entry, |
|
&(db->bb_free_root)); |
|
} |
|
|
|
node = rb_next(new_node); |
|
if (node) { |
|
entry = rb_entry(node, struct ext4_free_data, efd_node); |
|
ext4_try_merge_freed_extent(sbi, entry, new_entry, |
|
&(db->bb_free_root)); |
|
} |
|
|
|
spin_lock(&sbi->s_md_lock); |
|
list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list); |
|
sbi->s_mb_free_pending += clusters; |
|
spin_unlock(&sbi->s_md_lock); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Simple allocator for Ext4 fast commit replay path. It searches for blocks |
|
* linearly starting at the goal block and also excludes the blocks which |
|
* are going to be in use after fast commit replay. |
|
*/ |
|
static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, |
|
struct ext4_allocation_request *ar, int *errp) |
|
{ |
|
struct buffer_head *bitmap_bh; |
|
struct super_block *sb = ar->inode->i_sb; |
|
ext4_group_t group; |
|
ext4_grpblk_t blkoff; |
|
int i = sb->s_blocksize; |
|
ext4_fsblk_t goal, block; |
|
struct ext4_super_block *es = EXT4_SB(sb)->s_es; |
|
|
|
goal = ar->goal; |
|
if (goal < le32_to_cpu(es->s_first_data_block) || |
|
goal >= ext4_blocks_count(es)) |
|
goal = le32_to_cpu(es->s_first_data_block); |
|
|
|
ar->len = 0; |
|
ext4_get_group_no_and_offset(sb, goal, &group, &blkoff); |
|
for (; group < ext4_get_groups_count(sb); group++) { |
|
bitmap_bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR(bitmap_bh)) { |
|
*errp = PTR_ERR(bitmap_bh); |
|
pr_warn("Failed to read block bitmap\n"); |
|
return 0; |
|
} |
|
|
|
ext4_get_group_no_and_offset(sb, |
|
max(ext4_group_first_block_no(sb, group), goal), |
|
NULL, &blkoff); |
|
i = mb_find_next_zero_bit(bitmap_bh->b_data, sb->s_blocksize, |
|
blkoff); |
|
brelse(bitmap_bh); |
|
if (i >= sb->s_blocksize) |
|
continue; |
|
if (ext4_fc_replay_check_excluded(sb, |
|
ext4_group_first_block_no(sb, group) + i)) |
|
continue; |
|
break; |
|
} |
|
|
|
if (group >= ext4_get_groups_count(sb) && i >= sb->s_blocksize) |
|
return 0; |
|
|
|
block = ext4_group_first_block_no(sb, group) + i; |
|
ext4_mb_mark_bb(sb, block, 1, 1); |
|
ar->len = 1; |
|
|
|
return block; |
|
} |
|
|
|
static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block, |
|
unsigned long count) |
|
{ |
|
struct buffer_head *bitmap_bh; |
|
struct super_block *sb = inode->i_sb; |
|
struct ext4_group_desc *gdp; |
|
struct buffer_head *gdp_bh; |
|
ext4_group_t group; |
|
ext4_grpblk_t blkoff; |
|
int already_freed = 0, err, i; |
|
|
|
ext4_get_group_no_and_offset(sb, block, &group, &blkoff); |
|
bitmap_bh = ext4_read_block_bitmap(sb, group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
pr_warn("Failed to read block bitmap\n"); |
|
return; |
|
} |
|
gdp = ext4_get_group_desc(sb, group, &gdp_bh); |
|
if (!gdp) |
|
return; |
|
|
|
for (i = 0; i < count; i++) { |
|
if (!mb_test_bit(blkoff + i, bitmap_bh->b_data)) |
|
already_freed++; |
|
} |
|
mb_clear_bits(bitmap_bh->b_data, blkoff, count); |
|
err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh); |
|
if (err) |
|
return; |
|
ext4_free_group_clusters_set( |
|
sb, gdp, ext4_free_group_clusters(sb, gdp) + |
|
count - already_freed); |
|
ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh); |
|
ext4_group_desc_csum_set(sb, group, gdp); |
|
ext4_handle_dirty_metadata(NULL, NULL, gdp_bh); |
|
sync_dirty_buffer(bitmap_bh); |
|
sync_dirty_buffer(gdp_bh); |
|
brelse(bitmap_bh); |
|
} |
|
|
|
/** |
|
* ext4_free_blocks() -- Free given blocks and update quota |
|
* @handle: handle for this transaction |
|
* @inode: inode |
|
* @bh: optional buffer of the block to be freed |
|
* @block: starting physical block to be freed |
|
* @count: number of blocks to be freed |
|
* @flags: flags used by ext4_free_blocks |
|
*/ |
|
void ext4_free_blocks(handle_t *handle, struct inode *inode, |
|
struct buffer_head *bh, ext4_fsblk_t block, |
|
unsigned long count, int flags) |
|
{ |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct super_block *sb = inode->i_sb; |
|
struct ext4_group_desc *gdp; |
|
unsigned int overflow; |
|
ext4_grpblk_t bit; |
|
struct buffer_head *gd_bh; |
|
ext4_group_t block_group; |
|
struct ext4_sb_info *sbi; |
|
struct ext4_buddy e4b; |
|
unsigned int count_clusters; |
|
int err = 0; |
|
int ret; |
|
|
|
sbi = EXT4_SB(sb); |
|
|
|
if (sbi->s_mount_state & EXT4_FC_REPLAY) { |
|
ext4_free_blocks_simple(inode, block, count); |
|
return; |
|
} |
|
|
|
might_sleep(); |
|
if (bh) { |
|
if (block) |
|
BUG_ON(block != bh->b_blocknr); |
|
else |
|
block = bh->b_blocknr; |
|
} |
|
|
|
if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && |
|
!ext4_inode_block_valid(inode, block, count)) { |
|
ext4_error(sb, "Freeing blocks not in datazone - " |
|
"block = %llu, count = %lu", block, count); |
|
goto error_return; |
|
} |
|
|
|
ext4_debug("freeing block %llu\n", block); |
|
trace_ext4_free_blocks(inode, block, count, flags); |
|
|
|
if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { |
|
BUG_ON(count > 1); |
|
|
|
ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, |
|
inode, bh, block); |
|
} |
|
|
|
/* |
|
* If the extent to be freed does not begin on a cluster |
|
* boundary, we need to deal with partial clusters at the |
|
* beginning and end of the extent. Normally we will free |
|
* blocks at the beginning or the end unless we are explicitly |
|
* requested to avoid doing so. |
|
*/ |
|
overflow = EXT4_PBLK_COFF(sbi, block); |
|
if (overflow) { |
|
if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) { |
|
overflow = sbi->s_cluster_ratio - overflow; |
|
block += overflow; |
|
if (count > overflow) |
|
count -= overflow; |
|
else |
|
return; |
|
} else { |
|
block -= overflow; |
|
count += overflow; |
|
} |
|
} |
|
overflow = EXT4_LBLK_COFF(sbi, count); |
|
if (overflow) { |
|
if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) { |
|
if (count > overflow) |
|
count -= overflow; |
|
else |
|
return; |
|
} else |
|
count += sbi->s_cluster_ratio - overflow; |
|
} |
|
|
|
if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { |
|
int i; |
|
int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA; |
|
|
|
for (i = 0; i < count; i++) { |
|
cond_resched(); |
|
if (is_metadata) |
|
bh = sb_find_get_block(inode->i_sb, block + i); |
|
ext4_forget(handle, is_metadata, inode, bh, block + i); |
|
} |
|
} |
|
|
|
do_more: |
|
overflow = 0; |
|
ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
|
|
|
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT( |
|
ext4_get_group_info(sb, block_group)))) |
|
return; |
|
|
|
/* |
|
* Check to see if we are freeing blocks across a group |
|
* boundary. |
|
*/ |
|
if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) { |
|
overflow = EXT4_C2B(sbi, bit) + count - |
|
EXT4_BLOCKS_PER_GROUP(sb); |
|
count -= overflow; |
|
} |
|
count_clusters = EXT4_NUM_B2C(sbi, count); |
|
bitmap_bh = ext4_read_block_bitmap(sb, block_group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
bitmap_bh = NULL; |
|
goto error_return; |
|
} |
|
gdp = ext4_get_group_desc(sb, block_group, &gd_bh); |
|
if (!gdp) { |
|
err = -EIO; |
|
goto error_return; |
|
} |
|
|
|
if (in_range(ext4_block_bitmap(sb, gdp), block, count) || |
|
in_range(ext4_inode_bitmap(sb, gdp), block, count) || |
|
in_range(block, ext4_inode_table(sb, gdp), |
|
sbi->s_itb_per_group) || |
|
in_range(block + count - 1, ext4_inode_table(sb, gdp), |
|
sbi->s_itb_per_group)) { |
|
|
|
ext4_error(sb, "Freeing blocks in system zone - " |
|
"Block = %llu, count = %lu", block, count); |
|
/* err = 0. ext4_std_error should be a no op */ |
|
goto error_return; |
|
} |
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access"); |
|
err = ext4_journal_get_write_access(handle, bitmap_bh); |
|
if (err) |
|
goto error_return; |
|
|
|
/* |
|
* We are about to modify some metadata. Call the journal APIs |
|
* to unshare ->b_data if a currently-committing transaction is |
|
* using it |
|
*/ |
|
BUFFER_TRACE(gd_bh, "get_write_access"); |
|
err = ext4_journal_get_write_access(handle, gd_bh); |
|
if (err) |
|
goto error_return; |
|
#ifdef AGGRESSIVE_CHECK |
|
{ |
|
int i; |
|
for (i = 0; i < count_clusters; i++) |
|
BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data)); |
|
} |
|
#endif |
|
trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters); |
|
|
|
/* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */ |
|
err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b, |
|
GFP_NOFS|__GFP_NOFAIL); |
|
if (err) |
|
goto error_return; |
|
|
|
/* |
|
* We need to make sure we don't reuse the freed block until after the |
|
* transaction is committed. We make an exception if the inode is to be |
|
* written in writeback mode since writeback mode has weak data |
|
* consistency guarantees. |
|
*/ |
|
if (ext4_handle_valid(handle) && |
|
((flags & EXT4_FREE_BLOCKS_METADATA) || |
|
!ext4_should_writeback_data(inode))) { |
|
struct ext4_free_data *new_entry; |
|
/* |
|
* We use __GFP_NOFAIL because ext4_free_blocks() is not allowed |
|
* to fail. |
|
*/ |
|
new_entry = kmem_cache_alloc(ext4_free_data_cachep, |
|
GFP_NOFS|__GFP_NOFAIL); |
|
new_entry->efd_start_cluster = bit; |
|
new_entry->efd_group = block_group; |
|
new_entry->efd_count = count_clusters; |
|
new_entry->efd_tid = handle->h_transaction->t_tid; |
|
|
|
ext4_lock_group(sb, block_group); |
|
mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); |
|
ext4_mb_free_metadata(handle, &e4b, new_entry); |
|
} else { |
|
/* need to update group_info->bb_free and bitmap |
|
* with group lock held. generate_buddy look at |
|
* them with group lock_held |
|
*/ |
|
if (test_opt(sb, DISCARD)) { |
|
err = ext4_issue_discard(sb, block_group, bit, count, |
|
NULL); |
|
if (err && err != -EOPNOTSUPP) |
|
ext4_msg(sb, KERN_WARNING, "discard request in" |
|
" group:%d block:%d count:%lu failed" |
|
" with %d", block_group, bit, count, |
|
err); |
|
} else |
|
EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info); |
|
|
|
ext4_lock_group(sb, block_group); |
|
mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); |
|
mb_free_blocks(inode, &e4b, bit, count_clusters); |
|
} |
|
|
|
ret = ext4_free_group_clusters(sb, gdp) + count_clusters; |
|
ext4_free_group_clusters_set(sb, gdp, ret); |
|
ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh); |
|
ext4_group_desc_csum_set(sb, block_group, gdp); |
|
ext4_unlock_group(sb, block_group); |
|
|
|
if (sbi->s_log_groups_per_flex) { |
|
ext4_group_t flex_group = ext4_flex_group(sbi, block_group); |
|
atomic64_add(count_clusters, |
|
&sbi_array_rcu_deref(sbi, s_flex_groups, |
|
flex_group)->free_clusters); |
|
} |
|
|
|
/* |
|
* on a bigalloc file system, defer the s_freeclusters_counter |
|
* update to the caller (ext4_remove_space and friends) so they |
|
* can determine if a cluster freed here should be rereserved |
|
*/ |
|
if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) { |
|
if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) |
|
dquot_free_block(inode, EXT4_C2B(sbi, count_clusters)); |
|
percpu_counter_add(&sbi->s_freeclusters_counter, |
|
count_clusters); |
|
} |
|
|
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
/* We dirtied the bitmap block */ |
|
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); |
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
|
|
|
/* And the group descriptor block */ |
|
BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); |
|
ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); |
|
if (!err) |
|
err = ret; |
|
|
|
if (overflow && !err) { |
|
block += count; |
|
count = overflow; |
|
put_bh(bitmap_bh); |
|
goto do_more; |
|
} |
|
error_return: |
|
brelse(bitmap_bh); |
|
ext4_std_error(sb, err); |
|
return; |
|
} |
|
|
|
/** |
|
* ext4_group_add_blocks() -- Add given blocks to an existing group |
|
* @handle: handle to this transaction |
|
* @sb: super block |
|
* @block: start physical block to add to the block group |
|
* @count: number of blocks to free |
|
* |
|
* This marks the blocks as free in the bitmap and buddy. |
|
*/ |
|
int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, |
|
ext4_fsblk_t block, unsigned long count) |
|
{ |
|
struct buffer_head *bitmap_bh = NULL; |
|
struct buffer_head *gd_bh; |
|
ext4_group_t block_group; |
|
ext4_grpblk_t bit; |
|
unsigned int i; |
|
struct ext4_group_desc *desc; |
|
struct ext4_sb_info *sbi = EXT4_SB(sb); |
|
struct ext4_buddy e4b; |
|
int err = 0, ret, free_clusters_count; |
|
ext4_grpblk_t clusters_freed; |
|
ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block); |
|
ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1); |
|
unsigned long cluster_count = last_cluster - first_cluster + 1; |
|
|
|
ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); |
|
|
|
if (count == 0) |
|
return 0; |
|
|
|
ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
|
/* |
|
* Check to see if we are freeing blocks across a group |
|
* boundary. |
|
*/ |
|
if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) { |
|
ext4_warning(sb, "too many blocks added to group %u", |
|
block_group); |
|
err = -EINVAL; |
|
goto error_return; |
|
} |
|
|
|
bitmap_bh = ext4_read_block_bitmap(sb, block_group); |
|
if (IS_ERR(bitmap_bh)) { |
|
err = PTR_ERR(bitmap_bh); |
|
bitmap_bh = NULL; |
|
goto error_return; |
|
} |
|
|
|
desc = ext4_get_group_desc(sb, block_group, &gd_bh); |
|
if (!desc) { |
|
err = -EIO; |
|
goto error_return; |
|
} |
|
|
|
if (in_range(ext4_block_bitmap(sb, desc), block, count) || |
|
in_range(ext4_inode_bitmap(sb, desc), block, count) || |
|
in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) || |
|
in_range(block + count - 1, ext4_inode_table(sb, desc), |
|
sbi->s_itb_per_group)) { |
|
ext4_error(sb, "Adding blocks in system zones - " |
|
"Block = %llu, count = %lu", |
|
block, count); |
|
err = -EINVAL; |
|
goto error_return; |
|
} |
|
|
|
BUFFER_TRACE(bitmap_bh, "getting write access"); |
|
err = ext4_journal_get_write_access(handle, bitmap_bh); |
|
if (err) |
|
goto error_return; |
|
|
|
/* |
|
* We are about to modify some metadata. Call the journal APIs |
|
* to unshare ->b_data if a currently-committing transaction is |
|
* using it |
|
*/ |
|
BUFFER_TRACE(gd_bh, "get_write_access"); |
|
err = ext4_journal_get_write_access(handle, gd_bh); |
|
if (err) |
|
goto error_return; |
|
|
|
for (i = 0, clusters_freed = 0; i < cluster_count; i++) { |
|
BUFFER_TRACE(bitmap_bh, "clear bit"); |
|
if (!mb_test_bit(bit + i, bitmap_bh->b_data)) { |
|
ext4_error(sb, "bit already cleared for block %llu", |
|
(ext4_fsblk_t)(block + i)); |
|
BUFFER_TRACE(bitmap_bh, "bit already cleared"); |
|
} else { |
|
clusters_freed++; |
|
} |
|
} |
|
|
|
err = ext4_mb_load_buddy(sb, block_group, &e4b); |
|
if (err) |
|
goto error_return; |
|
|
|
/* |
|
* need to update group_info->bb_free and bitmap |
|
* with group lock held. generate_buddy look at |
|
* them with group lock_held |
|
*/ |
|
ext4_lock_group(sb, block_group); |
|
mb_clear_bits(bitmap_bh->b_data, bit, cluster_count); |
|
mb_free_blocks(NULL, &e4b, bit, cluster_count); |
|
free_clusters_count = clusters_freed + |
|
ext4_free_group_clusters(sb, desc); |
|
ext4_free_group_clusters_set(sb, desc, free_clusters_count); |
|
ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh); |
|
ext4_group_desc_csum_set(sb, block_group, desc); |
|
ext4_unlock_group(sb, block_group); |
|
percpu_counter_add(&sbi->s_freeclusters_counter, |
|
clusters_freed); |
|
|
|
if (sbi->s_log_groups_per_flex) { |
|
ext4_group_t flex_group = ext4_flex_group(sbi, block_group); |
|
atomic64_add(clusters_freed, |
|
&sbi_array_rcu_deref(sbi, s_flex_groups, |
|
flex_group)->free_clusters); |
|
} |
|
|
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
/* We dirtied the bitmap block */ |
|
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); |
|
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
|
|
|
/* And the group descriptor block */ |
|
BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); |
|
ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); |
|
if (!err) |
|
err = ret; |
|
|
|
error_return: |
|
brelse(bitmap_bh); |
|
ext4_std_error(sb, err); |
|
return err; |
|
} |
|
|
|
/** |
|
* ext4_trim_extent -- function to TRIM one single free extent in the group |
|
* @sb: super block for the file system |
|
* @start: starting block of the free extent in the alloc. group |
|
* @count: number of blocks to TRIM |
|
* @group: alloc. group we are working with |
|
* @e4b: ext4 buddy for the group |
|
* |
|
* Trim "count" blocks starting at "start" in the "group". To assure that no |
|
* one will allocate those blocks, mark it as used in buddy bitmap. This must |
|
* be called with under the group lock. |
|
*/ |
|
static int ext4_trim_extent(struct super_block *sb, int start, int count, |
|
ext4_group_t group, struct ext4_buddy *e4b) |
|
__releases(bitlock) |
|
__acquires(bitlock) |
|
{ |
|
struct ext4_free_extent ex; |
|
int ret = 0; |
|
|
|
trace_ext4_trim_extent(sb, group, start, count); |
|
|
|
assert_spin_locked(ext4_group_lock_ptr(sb, group)); |
|
|
|
ex.fe_start = start; |
|
ex.fe_group = group; |
|
ex.fe_len = count; |
|
|
|
/* |
|
* Mark blocks used, so no one can reuse them while |
|
* being trimmed. |
|
*/ |
|
mb_mark_used(e4b, &ex); |
|
ext4_unlock_group(sb, group); |
|
ret = ext4_issue_discard(sb, group, start, count, NULL); |
|
ext4_lock_group(sb, group); |
|
mb_free_blocks(NULL, e4b, start, ex.fe_len); |
|
return ret; |
|
} |
|
|
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/** |
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* ext4_trim_all_free -- function to trim all free space in alloc. group |
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* @sb: super block for file system |
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* @group: group to be trimmed |
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* @start: first group block to examine |
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* @max: last group block to examine |
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* @minblocks: minimum extent block count |
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* |
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* ext4_trim_all_free walks through group's buddy bitmap searching for free |
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* extents. When the free block is found, ext4_trim_extent is called to TRIM |
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* the extent. |
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* |
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* |
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* ext4_trim_all_free walks through group's block bitmap searching for free |
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* extents. When the free extent is found, mark it as used in group buddy |
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* bitmap. Then issue a TRIM command on this extent and free the extent in |
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* the group buddy bitmap. This is done until whole group is scanned. |
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*/ |
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static ext4_grpblk_t |
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ext4_trim_all_free(struct super_block *sb, ext4_group_t group, |
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ext4_grpblk_t start, ext4_grpblk_t max, |
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ext4_grpblk_t minblocks) |
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{ |
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void *bitmap; |
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ext4_grpblk_t next, count = 0, free_count = 0; |
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struct ext4_buddy e4b; |
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int ret = 0; |
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|
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trace_ext4_trim_all_free(sb, group, start, max); |
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|
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ret = ext4_mb_load_buddy(sb, group, &e4b); |
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if (ret) { |
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ext4_warning(sb, "Error %d loading buddy information for %u", |
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ret, group); |
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return ret; |
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} |
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bitmap = e4b.bd_bitmap; |
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|
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ext4_lock_group(sb, group); |
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if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) && |
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minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) |
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goto out; |
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|
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start = (e4b.bd_info->bb_first_free > start) ? |
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e4b.bd_info->bb_first_free : start; |
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|
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while (start <= max) { |
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start = mb_find_next_zero_bit(bitmap, max + 1, start); |
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if (start > max) |
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break; |
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next = mb_find_next_bit(bitmap, max + 1, start); |
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|
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if ((next - start) >= minblocks) { |
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ret = ext4_trim_extent(sb, start, |
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next - start, group, &e4b); |
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if (ret && ret != -EOPNOTSUPP) |
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break; |
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ret = 0; |
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count += next - start; |
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} |
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free_count += next - start; |
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start = next + 1; |
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|
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if (fatal_signal_pending(current)) { |
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count = -ERESTARTSYS; |
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break; |
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} |
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|
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if (need_resched()) { |
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ext4_unlock_group(sb, group); |
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cond_resched(); |
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ext4_lock_group(sb, group); |
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} |
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|
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if ((e4b.bd_info->bb_free - free_count) < minblocks) |
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break; |
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} |
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|
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if (!ret) { |
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ret = count; |
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EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info); |
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} |
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out: |
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ext4_unlock_group(sb, group); |
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ext4_mb_unload_buddy(&e4b); |
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|
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ext4_debug("trimmed %d blocks in the group %d\n", |
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count, group); |
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|
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return ret; |
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} |
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|
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/** |
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* ext4_trim_fs() -- trim ioctl handle function |
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* @sb: superblock for filesystem |
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* @range: fstrim_range structure |
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* |
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* start: First Byte to trim |
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* len: number of Bytes to trim from start |
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* minlen: minimum extent length in Bytes |
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* ext4_trim_fs goes through all allocation groups containing Bytes from |
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* start to start+len. For each such a group ext4_trim_all_free function |
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* is invoked to trim all free space. |
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*/ |
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int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) |
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{ |
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struct ext4_group_info *grp; |
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ext4_group_t group, first_group, last_group; |
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ext4_grpblk_t cnt = 0, first_cluster, last_cluster; |
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uint64_t start, end, minlen, trimmed = 0; |
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ext4_fsblk_t first_data_blk = |
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le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
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ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es); |
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int ret = 0; |
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|
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start = range->start >> sb->s_blocksize_bits; |
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end = start + (range->len >> sb->s_blocksize_bits) - 1; |
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minlen = EXT4_NUM_B2C(EXT4_SB(sb), |
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range->minlen >> sb->s_blocksize_bits); |
|
|
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if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) || |
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start >= max_blks || |
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range->len < sb->s_blocksize) |
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return -EINVAL; |
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if (end >= max_blks) |
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end = max_blks - 1; |
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if (end <= first_data_blk) |
|
goto out; |
|
if (start < first_data_blk) |
|
start = first_data_blk; |
|
|
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/* Determine first and last group to examine based on start and end */ |
|
ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start, |
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&first_group, &first_cluster); |
|
ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end, |
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&last_group, &last_cluster); |
|
|
|
/* end now represents the last cluster to discard in this group */ |
|
end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; |
|
|
|
for (group = first_group; group <= last_group; group++) { |
|
grp = ext4_get_group_info(sb, group); |
|
/* We only do this if the grp has never been initialized */ |
|
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
|
ret = ext4_mb_init_group(sb, group, GFP_NOFS); |
|
if (ret) |
|
break; |
|
} |
|
|
|
/* |
|
* For all the groups except the last one, last cluster will |
|
* always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to |
|
* change it for the last group, note that last_cluster is |
|
* already computed earlier by ext4_get_group_no_and_offset() |
|
*/ |
|
if (group == last_group) |
|
end = last_cluster; |
|
|
|
if (grp->bb_free >= minlen) { |
|
cnt = ext4_trim_all_free(sb, group, first_cluster, |
|
end, minlen); |
|
if (cnt < 0) { |
|
ret = cnt; |
|
break; |
|
} |
|
trimmed += cnt; |
|
} |
|
|
|
/* |
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* For every group except the first one, we are sure |
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* that the first cluster to discard will be cluster #0. |
|
*/ |
|
first_cluster = 0; |
|
} |
|
|
|
if (!ret) |
|
atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen); |
|
|
|
out: |
|
range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits; |
|
return ret; |
|
} |
|
|
|
/* Iterate all the free extents in the group. */ |
|
int |
|
ext4_mballoc_query_range( |
|
struct super_block *sb, |
|
ext4_group_t group, |
|
ext4_grpblk_t start, |
|
ext4_grpblk_t end, |
|
ext4_mballoc_query_range_fn formatter, |
|
void *priv) |
|
{ |
|
void *bitmap; |
|
ext4_grpblk_t next; |
|
struct ext4_buddy e4b; |
|
int error; |
|
|
|
error = ext4_mb_load_buddy(sb, group, &e4b); |
|
if (error) |
|
return error; |
|
bitmap = e4b.bd_bitmap; |
|
|
|
ext4_lock_group(sb, group); |
|
|
|
start = (e4b.bd_info->bb_first_free > start) ? |
|
e4b.bd_info->bb_first_free : start; |
|
if (end >= EXT4_CLUSTERS_PER_GROUP(sb)) |
|
end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; |
|
|
|
while (start <= end) { |
|
start = mb_find_next_zero_bit(bitmap, end + 1, start); |
|
if (start > end) |
|
break; |
|
next = mb_find_next_bit(bitmap, end + 1, start); |
|
|
|
ext4_unlock_group(sb, group); |
|
error = formatter(sb, group, start, next - start, priv); |
|
if (error) |
|
goto out_unload; |
|
ext4_lock_group(sb, group); |
|
|
|
start = next + 1; |
|
} |
|
|
|
ext4_unlock_group(sb, group); |
|
out_unload: |
|
ext4_mb_unload_buddy(&e4b); |
|
|
|
return error; |
|
}
|
|
|