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2717 lines
67 KiB
2717 lines
67 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2012 Fusion-io All rights reserved. |
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* Copyright (C) 2012 Intel Corp. All rights reserved. |
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*/ |
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|
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#include <linux/sched.h> |
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#include <linux/bio.h> |
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#include <linux/slab.h> |
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#include <linux/blkdev.h> |
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#include <linux/raid/pq.h> |
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#include <linux/hash.h> |
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#include <linux/list_sort.h> |
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#include <linux/raid/xor.h> |
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#include <linux/mm.h> |
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#include "ctree.h" |
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#include "disk-io.h" |
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#include "volumes.h" |
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#include "raid56.h" |
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#include "async-thread.h" |
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|
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/* set when additional merges to this rbio are not allowed */ |
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#define RBIO_RMW_LOCKED_BIT 1 |
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|
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/* |
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* set when this rbio is sitting in the hash, but it is just a cache |
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* of past RMW |
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*/ |
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#define RBIO_CACHE_BIT 2 |
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|
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/* |
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* set when it is safe to trust the stripe_pages for caching |
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*/ |
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#define RBIO_CACHE_READY_BIT 3 |
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#define RBIO_CACHE_SIZE 1024 |
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#define BTRFS_STRIPE_HASH_TABLE_BITS 11 |
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|
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/* Used by the raid56 code to lock stripes for read/modify/write */ |
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struct btrfs_stripe_hash { |
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struct list_head hash_list; |
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spinlock_t lock; |
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}; |
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|
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/* Used by the raid56 code to lock stripes for read/modify/write */ |
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struct btrfs_stripe_hash_table { |
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struct list_head stripe_cache; |
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spinlock_t cache_lock; |
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int cache_size; |
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struct btrfs_stripe_hash table[]; |
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}; |
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enum btrfs_rbio_ops { |
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BTRFS_RBIO_WRITE, |
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BTRFS_RBIO_READ_REBUILD, |
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BTRFS_RBIO_PARITY_SCRUB, |
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BTRFS_RBIO_REBUILD_MISSING, |
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}; |
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|
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struct btrfs_raid_bio { |
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struct btrfs_fs_info *fs_info; |
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struct btrfs_bio *bbio; |
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|
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/* while we're doing rmw on a stripe |
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* we put it into a hash table so we can |
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* lock the stripe and merge more rbios |
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* into it. |
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*/ |
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struct list_head hash_list; |
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|
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/* |
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* LRU list for the stripe cache |
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*/ |
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struct list_head stripe_cache; |
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|
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/* |
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* for scheduling work in the helper threads |
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*/ |
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struct btrfs_work work; |
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|
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/* |
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* bio list and bio_list_lock are used |
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* to add more bios into the stripe |
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* in hopes of avoiding the full rmw |
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*/ |
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struct bio_list bio_list; |
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spinlock_t bio_list_lock; |
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|
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/* also protected by the bio_list_lock, the |
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* plug list is used by the plugging code |
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* to collect partial bios while plugged. The |
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* stripe locking code also uses it to hand off |
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* the stripe lock to the next pending IO |
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*/ |
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struct list_head plug_list; |
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|
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/* |
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* flags that tell us if it is safe to |
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* merge with this bio |
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*/ |
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unsigned long flags; |
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|
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/* size of each individual stripe on disk */ |
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int stripe_len; |
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|
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/* number of data stripes (no p/q) */ |
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int nr_data; |
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int real_stripes; |
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int stripe_npages; |
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/* |
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* set if we're doing a parity rebuild |
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* for a read from higher up, which is handled |
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* differently from a parity rebuild as part of |
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* rmw |
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*/ |
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enum btrfs_rbio_ops operation; |
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/* first bad stripe */ |
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int faila; |
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/* second bad stripe (for raid6 use) */ |
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int failb; |
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int scrubp; |
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/* |
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* number of pages needed to represent the full |
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* stripe |
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*/ |
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int nr_pages; |
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|
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/* |
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* size of all the bios in the bio_list. This |
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* helps us decide if the rbio maps to a full |
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* stripe or not |
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*/ |
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int bio_list_bytes; |
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|
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int generic_bio_cnt; |
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refcount_t refs; |
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atomic_t stripes_pending; |
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|
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atomic_t error; |
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/* |
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* these are two arrays of pointers. We allocate the |
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* rbio big enough to hold them both and setup their |
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* locations when the rbio is allocated |
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*/ |
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|
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/* pointers to pages that we allocated for |
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* reading/writing stripes directly from the disk (including P/Q) |
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*/ |
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struct page **stripe_pages; |
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|
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/* |
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* pointers to the pages in the bio_list. Stored |
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* here for faster lookup |
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*/ |
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struct page **bio_pages; |
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|
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/* |
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* bitmap to record which horizontal stripe has data |
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*/ |
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unsigned long *dbitmap; |
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|
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/* allocated with real_stripes-many pointers for finish_*() calls */ |
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void **finish_pointers; |
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|
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/* allocated with stripe_npages-many bits for finish_*() calls */ |
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unsigned long *finish_pbitmap; |
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}; |
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static int __raid56_parity_recover(struct btrfs_raid_bio *rbio); |
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static noinline void finish_rmw(struct btrfs_raid_bio *rbio); |
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static void rmw_work(struct btrfs_work *work); |
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static void read_rebuild_work(struct btrfs_work *work); |
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static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio); |
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static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed); |
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static void __free_raid_bio(struct btrfs_raid_bio *rbio); |
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static void index_rbio_pages(struct btrfs_raid_bio *rbio); |
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static int alloc_rbio_pages(struct btrfs_raid_bio *rbio); |
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|
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static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, |
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int need_check); |
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static void scrub_parity_work(struct btrfs_work *work); |
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|
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static void start_async_work(struct btrfs_raid_bio *rbio, btrfs_func_t work_func) |
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{ |
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btrfs_init_work(&rbio->work, work_func, NULL, NULL); |
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btrfs_queue_work(rbio->fs_info->rmw_workers, &rbio->work); |
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} |
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|
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/* |
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* the stripe hash table is used for locking, and to collect |
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* bios in hopes of making a full stripe |
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*/ |
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int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info) |
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{ |
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struct btrfs_stripe_hash_table *table; |
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struct btrfs_stripe_hash_table *x; |
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struct btrfs_stripe_hash *cur; |
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struct btrfs_stripe_hash *h; |
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int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS; |
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int i; |
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if (info->stripe_hash_table) |
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return 0; |
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/* |
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* The table is large, starting with order 4 and can go as high as |
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* order 7 in case lock debugging is turned on. |
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* |
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* Try harder to allocate and fallback to vmalloc to lower the chance |
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* of a failing mount. |
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*/ |
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table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL); |
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if (!table) |
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return -ENOMEM; |
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spin_lock_init(&table->cache_lock); |
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INIT_LIST_HEAD(&table->stripe_cache); |
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h = table->table; |
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for (i = 0; i < num_entries; i++) { |
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cur = h + i; |
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INIT_LIST_HEAD(&cur->hash_list); |
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spin_lock_init(&cur->lock); |
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} |
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x = cmpxchg(&info->stripe_hash_table, NULL, table); |
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if (x) |
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kvfree(x); |
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return 0; |
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} |
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|
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/* |
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* caching an rbio means to copy anything from the |
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* bio_pages array into the stripe_pages array. We |
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* use the page uptodate bit in the stripe cache array |
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* to indicate if it has valid data |
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* |
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* once the caching is done, we set the cache ready |
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* bit. |
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*/ |
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static void cache_rbio_pages(struct btrfs_raid_bio *rbio) |
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{ |
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int i; |
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char *s; |
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char *d; |
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int ret; |
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ret = alloc_rbio_pages(rbio); |
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if (ret) |
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return; |
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for (i = 0; i < rbio->nr_pages; i++) { |
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if (!rbio->bio_pages[i]) |
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continue; |
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s = kmap(rbio->bio_pages[i]); |
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d = kmap(rbio->stripe_pages[i]); |
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copy_page(d, s); |
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kunmap(rbio->bio_pages[i]); |
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kunmap(rbio->stripe_pages[i]); |
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SetPageUptodate(rbio->stripe_pages[i]); |
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} |
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set_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
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} |
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|
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/* |
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* we hash on the first logical address of the stripe |
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*/ |
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static int rbio_bucket(struct btrfs_raid_bio *rbio) |
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{ |
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u64 num = rbio->bbio->raid_map[0]; |
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|
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/* |
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* we shift down quite a bit. We're using byte |
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* addressing, and most of the lower bits are zeros. |
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* This tends to upset hash_64, and it consistently |
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* returns just one or two different values. |
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* |
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* shifting off the lower bits fixes things. |
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*/ |
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return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS); |
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} |
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|
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/* |
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* stealing an rbio means taking all the uptodate pages from the stripe |
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* array in the source rbio and putting them into the destination rbio |
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*/ |
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static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest) |
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{ |
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int i; |
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struct page *s; |
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struct page *d; |
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if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags)) |
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return; |
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for (i = 0; i < dest->nr_pages; i++) { |
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s = src->stripe_pages[i]; |
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if (!s || !PageUptodate(s)) { |
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continue; |
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} |
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d = dest->stripe_pages[i]; |
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if (d) |
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__free_page(d); |
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dest->stripe_pages[i] = s; |
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src->stripe_pages[i] = NULL; |
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} |
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} |
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/* |
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* merging means we take the bio_list from the victim and |
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* splice it into the destination. The victim should |
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* be discarded afterwards. |
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* |
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* must be called with dest->rbio_list_lock held |
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*/ |
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static void merge_rbio(struct btrfs_raid_bio *dest, |
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struct btrfs_raid_bio *victim) |
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{ |
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bio_list_merge(&dest->bio_list, &victim->bio_list); |
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dest->bio_list_bytes += victim->bio_list_bytes; |
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dest->generic_bio_cnt += victim->generic_bio_cnt; |
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bio_list_init(&victim->bio_list); |
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} |
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/* |
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* used to prune items that are in the cache. The caller |
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* must hold the hash table lock. |
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*/ |
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static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio) |
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{ |
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int bucket = rbio_bucket(rbio); |
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struct btrfs_stripe_hash_table *table; |
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struct btrfs_stripe_hash *h; |
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int freeit = 0; |
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/* |
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* check the bit again under the hash table lock. |
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*/ |
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) |
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return; |
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table = rbio->fs_info->stripe_hash_table; |
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h = table->table + bucket; |
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|
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/* hold the lock for the bucket because we may be |
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* removing it from the hash table |
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*/ |
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spin_lock(&h->lock); |
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|
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/* |
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* hold the lock for the bio list because we need |
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* to make sure the bio list is empty |
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*/ |
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spin_lock(&rbio->bio_list_lock); |
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if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) { |
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list_del_init(&rbio->stripe_cache); |
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table->cache_size -= 1; |
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freeit = 1; |
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|
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/* if the bio list isn't empty, this rbio is |
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* still involved in an IO. We take it out |
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* of the cache list, and drop the ref that |
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* was held for the list. |
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* |
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* If the bio_list was empty, we also remove |
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* the rbio from the hash_table, and drop |
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* the corresponding ref |
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*/ |
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if (bio_list_empty(&rbio->bio_list)) { |
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if (!list_empty(&rbio->hash_list)) { |
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list_del_init(&rbio->hash_list); |
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refcount_dec(&rbio->refs); |
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BUG_ON(!list_empty(&rbio->plug_list)); |
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} |
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} |
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} |
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spin_unlock(&rbio->bio_list_lock); |
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spin_unlock(&h->lock); |
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|
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if (freeit) |
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__free_raid_bio(rbio); |
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} |
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|
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/* |
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* prune a given rbio from the cache |
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*/ |
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static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio) |
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{ |
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struct btrfs_stripe_hash_table *table; |
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unsigned long flags; |
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|
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) |
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return; |
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table = rbio->fs_info->stripe_hash_table; |
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spin_lock_irqsave(&table->cache_lock, flags); |
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__remove_rbio_from_cache(rbio); |
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spin_unlock_irqrestore(&table->cache_lock, flags); |
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} |
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|
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/* |
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* remove everything in the cache |
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*/ |
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static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info) |
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{ |
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struct btrfs_stripe_hash_table *table; |
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unsigned long flags; |
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struct btrfs_raid_bio *rbio; |
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|
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table = info->stripe_hash_table; |
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|
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spin_lock_irqsave(&table->cache_lock, flags); |
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while (!list_empty(&table->stripe_cache)) { |
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rbio = list_entry(table->stripe_cache.next, |
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struct btrfs_raid_bio, |
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stripe_cache); |
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__remove_rbio_from_cache(rbio); |
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} |
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spin_unlock_irqrestore(&table->cache_lock, flags); |
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} |
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|
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/* |
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* remove all cached entries and free the hash table |
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* used by unmount |
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*/ |
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void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info) |
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{ |
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if (!info->stripe_hash_table) |
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return; |
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btrfs_clear_rbio_cache(info); |
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kvfree(info->stripe_hash_table); |
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info->stripe_hash_table = NULL; |
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} |
|
|
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/* |
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* insert an rbio into the stripe cache. It |
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* must have already been prepared by calling |
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* cache_rbio_pages |
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* |
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* If this rbio was already cached, it gets |
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* moved to the front of the lru. |
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* |
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* If the size of the rbio cache is too big, we |
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* prune an item. |
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*/ |
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static void cache_rbio(struct btrfs_raid_bio *rbio) |
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{ |
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struct btrfs_stripe_hash_table *table; |
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unsigned long flags; |
|
|
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if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags)) |
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return; |
|
|
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table = rbio->fs_info->stripe_hash_table; |
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|
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spin_lock_irqsave(&table->cache_lock, flags); |
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spin_lock(&rbio->bio_list_lock); |
|
|
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/* bump our ref if we were not in the list before */ |
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if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags)) |
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refcount_inc(&rbio->refs); |
|
|
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if (!list_empty(&rbio->stripe_cache)){ |
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list_move(&rbio->stripe_cache, &table->stripe_cache); |
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} else { |
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list_add(&rbio->stripe_cache, &table->stripe_cache); |
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table->cache_size += 1; |
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} |
|
|
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spin_unlock(&rbio->bio_list_lock); |
|
|
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if (table->cache_size > RBIO_CACHE_SIZE) { |
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struct btrfs_raid_bio *found; |
|
|
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found = list_entry(table->stripe_cache.prev, |
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struct btrfs_raid_bio, |
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stripe_cache); |
|
|
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if (found != rbio) |
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__remove_rbio_from_cache(found); |
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} |
|
|
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spin_unlock_irqrestore(&table->cache_lock, flags); |
|
} |
|
|
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/* |
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* helper function to run the xor_blocks api. It is only |
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* able to do MAX_XOR_BLOCKS at a time, so we need to |
|
* loop through. |
|
*/ |
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static void run_xor(void **pages, int src_cnt, ssize_t len) |
|
{ |
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int src_off = 0; |
|
int xor_src_cnt = 0; |
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void *dest = pages[src_cnt]; |
|
|
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while(src_cnt > 0) { |
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xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS); |
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xor_blocks(xor_src_cnt, len, dest, pages + src_off); |
|
|
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src_cnt -= xor_src_cnt; |
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src_off += xor_src_cnt; |
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} |
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} |
|
|
|
/* |
|
* Returns true if the bio list inside this rbio covers an entire stripe (no |
|
* rmw required). |
|
*/ |
|
static int rbio_is_full(struct btrfs_raid_bio *rbio) |
|
{ |
|
unsigned long flags; |
|
unsigned long size = rbio->bio_list_bytes; |
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int ret = 1; |
|
|
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spin_lock_irqsave(&rbio->bio_list_lock, flags); |
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if (size != rbio->nr_data * rbio->stripe_len) |
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ret = 0; |
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BUG_ON(size > rbio->nr_data * rbio->stripe_len); |
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spin_unlock_irqrestore(&rbio->bio_list_lock, flags); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* returns 1 if it is safe to merge two rbios together. |
|
* The merging is safe if the two rbios correspond to |
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* the same stripe and if they are both going in the same |
|
* direction (read vs write), and if neither one is |
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* locked for final IO |
|
* |
|
* The caller is responsible for locking such that |
|
* rmw_locked is safe to test |
|
*/ |
|
static int rbio_can_merge(struct btrfs_raid_bio *last, |
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struct btrfs_raid_bio *cur) |
|
{ |
|
if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) || |
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test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) |
|
return 0; |
|
|
|
/* |
|
* we can't merge with cached rbios, since the |
|
* idea is that when we merge the destination |
|
* rbio is going to run our IO for us. We can |
|
* steal from cached rbios though, other functions |
|
* handle that. |
|
*/ |
|
if (test_bit(RBIO_CACHE_BIT, &last->flags) || |
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test_bit(RBIO_CACHE_BIT, &cur->flags)) |
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return 0; |
|
|
|
if (last->bbio->raid_map[0] != |
|
cur->bbio->raid_map[0]) |
|
return 0; |
|
|
|
/* we can't merge with different operations */ |
|
if (last->operation != cur->operation) |
|
return 0; |
|
/* |
|
* We've need read the full stripe from the drive. |
|
* check and repair the parity and write the new results. |
|
* |
|
* We're not allowed to add any new bios to the |
|
* bio list here, anyone else that wants to |
|
* change this stripe needs to do their own rmw. |
|
*/ |
|
if (last->operation == BTRFS_RBIO_PARITY_SCRUB) |
|
return 0; |
|
|
|
if (last->operation == BTRFS_RBIO_REBUILD_MISSING) |
|
return 0; |
|
|
|
if (last->operation == BTRFS_RBIO_READ_REBUILD) { |
|
int fa = last->faila; |
|
int fb = last->failb; |
|
int cur_fa = cur->faila; |
|
int cur_fb = cur->failb; |
|
|
|
if (last->faila >= last->failb) { |
|
fa = last->failb; |
|
fb = last->faila; |
|
} |
|
|
|
if (cur->faila >= cur->failb) { |
|
cur_fa = cur->failb; |
|
cur_fb = cur->faila; |
|
} |
|
|
|
if (fa != cur_fa || fb != cur_fb) |
|
return 0; |
|
} |
|
return 1; |
|
} |
|
|
|
static int rbio_stripe_page_index(struct btrfs_raid_bio *rbio, int stripe, |
|
int index) |
|
{ |
|
return stripe * rbio->stripe_npages + index; |
|
} |
|
|
|
/* |
|
* these are just the pages from the rbio array, not from anything |
|
* the FS sent down to us |
|
*/ |
|
static struct page *rbio_stripe_page(struct btrfs_raid_bio *rbio, int stripe, |
|
int index) |
|
{ |
|
return rbio->stripe_pages[rbio_stripe_page_index(rbio, stripe, index)]; |
|
} |
|
|
|
/* |
|
* helper to index into the pstripe |
|
*/ |
|
static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index) |
|
{ |
|
return rbio_stripe_page(rbio, rbio->nr_data, index); |
|
} |
|
|
|
/* |
|
* helper to index into the qstripe, returns null |
|
* if there is no qstripe |
|
*/ |
|
static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index) |
|
{ |
|
if (rbio->nr_data + 1 == rbio->real_stripes) |
|
return NULL; |
|
return rbio_stripe_page(rbio, rbio->nr_data + 1, index); |
|
} |
|
|
|
/* |
|
* The first stripe in the table for a logical address |
|
* has the lock. rbios are added in one of three ways: |
|
* |
|
* 1) Nobody has the stripe locked yet. The rbio is given |
|
* the lock and 0 is returned. The caller must start the IO |
|
* themselves. |
|
* |
|
* 2) Someone has the stripe locked, but we're able to merge |
|
* with the lock owner. The rbio is freed and the IO will |
|
* start automatically along with the existing rbio. 1 is returned. |
|
* |
|
* 3) Someone has the stripe locked, but we're not able to merge. |
|
* The rbio is added to the lock owner's plug list, or merged into |
|
* an rbio already on the plug list. When the lock owner unlocks, |
|
* the next rbio on the list is run and the IO is started automatically. |
|
* 1 is returned |
|
* |
|
* If we return 0, the caller still owns the rbio and must continue with |
|
* IO submission. If we return 1, the caller must assume the rbio has |
|
* already been freed. |
|
*/ |
|
static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio) |
|
{ |
|
struct btrfs_stripe_hash *h; |
|
struct btrfs_raid_bio *cur; |
|
struct btrfs_raid_bio *pending; |
|
unsigned long flags; |
|
struct btrfs_raid_bio *freeit = NULL; |
|
struct btrfs_raid_bio *cache_drop = NULL; |
|
int ret = 0; |
|
|
|
h = rbio->fs_info->stripe_hash_table->table + rbio_bucket(rbio); |
|
|
|
spin_lock_irqsave(&h->lock, flags); |
|
list_for_each_entry(cur, &h->hash_list, hash_list) { |
|
if (cur->bbio->raid_map[0] != rbio->bbio->raid_map[0]) |
|
continue; |
|
|
|
spin_lock(&cur->bio_list_lock); |
|
|
|
/* Can we steal this cached rbio's pages? */ |
|
if (bio_list_empty(&cur->bio_list) && |
|
list_empty(&cur->plug_list) && |
|
test_bit(RBIO_CACHE_BIT, &cur->flags) && |
|
!test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) { |
|
list_del_init(&cur->hash_list); |
|
refcount_dec(&cur->refs); |
|
|
|
steal_rbio(cur, rbio); |
|
cache_drop = cur; |
|
spin_unlock(&cur->bio_list_lock); |
|
|
|
goto lockit; |
|
} |
|
|
|
/* Can we merge into the lock owner? */ |
|
if (rbio_can_merge(cur, rbio)) { |
|
merge_rbio(cur, rbio); |
|
spin_unlock(&cur->bio_list_lock); |
|
freeit = rbio; |
|
ret = 1; |
|
goto out; |
|
} |
|
|
|
|
|
/* |
|
* We couldn't merge with the running rbio, see if we can merge |
|
* with the pending ones. We don't have to check for rmw_locked |
|
* because there is no way they are inside finish_rmw right now |
|
*/ |
|
list_for_each_entry(pending, &cur->plug_list, plug_list) { |
|
if (rbio_can_merge(pending, rbio)) { |
|
merge_rbio(pending, rbio); |
|
spin_unlock(&cur->bio_list_lock); |
|
freeit = rbio; |
|
ret = 1; |
|
goto out; |
|
} |
|
} |
|
|
|
/* |
|
* No merging, put us on the tail of the plug list, our rbio |
|
* will be started with the currently running rbio unlocks |
|
*/ |
|
list_add_tail(&rbio->plug_list, &cur->plug_list); |
|
spin_unlock(&cur->bio_list_lock); |
|
ret = 1; |
|
goto out; |
|
} |
|
lockit: |
|
refcount_inc(&rbio->refs); |
|
list_add(&rbio->hash_list, &h->hash_list); |
|
out: |
|
spin_unlock_irqrestore(&h->lock, flags); |
|
if (cache_drop) |
|
remove_rbio_from_cache(cache_drop); |
|
if (freeit) |
|
__free_raid_bio(freeit); |
|
return ret; |
|
} |
|
|
|
/* |
|
* called as rmw or parity rebuild is completed. If the plug list has more |
|
* rbios waiting for this stripe, the next one on the list will be started |
|
*/ |
|
static noinline void unlock_stripe(struct btrfs_raid_bio *rbio) |
|
{ |
|
int bucket; |
|
struct btrfs_stripe_hash *h; |
|
unsigned long flags; |
|
int keep_cache = 0; |
|
|
|
bucket = rbio_bucket(rbio); |
|
h = rbio->fs_info->stripe_hash_table->table + bucket; |
|
|
|
if (list_empty(&rbio->plug_list)) |
|
cache_rbio(rbio); |
|
|
|
spin_lock_irqsave(&h->lock, flags); |
|
spin_lock(&rbio->bio_list_lock); |
|
|
|
if (!list_empty(&rbio->hash_list)) { |
|
/* |
|
* if we're still cached and there is no other IO |
|
* to perform, just leave this rbio here for others |
|
* to steal from later |
|
*/ |
|
if (list_empty(&rbio->plug_list) && |
|
test_bit(RBIO_CACHE_BIT, &rbio->flags)) { |
|
keep_cache = 1; |
|
clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
|
BUG_ON(!bio_list_empty(&rbio->bio_list)); |
|
goto done; |
|
} |
|
|
|
list_del_init(&rbio->hash_list); |
|
refcount_dec(&rbio->refs); |
|
|
|
/* |
|
* we use the plug list to hold all the rbios |
|
* waiting for the chance to lock this stripe. |
|
* hand the lock over to one of them. |
|
*/ |
|
if (!list_empty(&rbio->plug_list)) { |
|
struct btrfs_raid_bio *next; |
|
struct list_head *head = rbio->plug_list.next; |
|
|
|
next = list_entry(head, struct btrfs_raid_bio, |
|
plug_list); |
|
|
|
list_del_init(&rbio->plug_list); |
|
|
|
list_add(&next->hash_list, &h->hash_list); |
|
refcount_inc(&next->refs); |
|
spin_unlock(&rbio->bio_list_lock); |
|
spin_unlock_irqrestore(&h->lock, flags); |
|
|
|
if (next->operation == BTRFS_RBIO_READ_REBUILD) |
|
start_async_work(next, read_rebuild_work); |
|
else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) { |
|
steal_rbio(rbio, next); |
|
start_async_work(next, read_rebuild_work); |
|
} else if (next->operation == BTRFS_RBIO_WRITE) { |
|
steal_rbio(rbio, next); |
|
start_async_work(next, rmw_work); |
|
} else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) { |
|
steal_rbio(rbio, next); |
|
start_async_work(next, scrub_parity_work); |
|
} |
|
|
|
goto done_nolock; |
|
} |
|
} |
|
done: |
|
spin_unlock(&rbio->bio_list_lock); |
|
spin_unlock_irqrestore(&h->lock, flags); |
|
|
|
done_nolock: |
|
if (!keep_cache) |
|
remove_rbio_from_cache(rbio); |
|
} |
|
|
|
static void __free_raid_bio(struct btrfs_raid_bio *rbio) |
|
{ |
|
int i; |
|
|
|
if (!refcount_dec_and_test(&rbio->refs)) |
|
return; |
|
|
|
WARN_ON(!list_empty(&rbio->stripe_cache)); |
|
WARN_ON(!list_empty(&rbio->hash_list)); |
|
WARN_ON(!bio_list_empty(&rbio->bio_list)); |
|
|
|
for (i = 0; i < rbio->nr_pages; i++) { |
|
if (rbio->stripe_pages[i]) { |
|
__free_page(rbio->stripe_pages[i]); |
|
rbio->stripe_pages[i] = NULL; |
|
} |
|
} |
|
|
|
btrfs_put_bbio(rbio->bbio); |
|
kfree(rbio); |
|
} |
|
|
|
static void rbio_endio_bio_list(struct bio *cur, blk_status_t err) |
|
{ |
|
struct bio *next; |
|
|
|
while (cur) { |
|
next = cur->bi_next; |
|
cur->bi_next = NULL; |
|
cur->bi_status = err; |
|
bio_endio(cur); |
|
cur = next; |
|
} |
|
} |
|
|
|
/* |
|
* this frees the rbio and runs through all the bios in the |
|
* bio_list and calls end_io on them |
|
*/ |
|
static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err) |
|
{ |
|
struct bio *cur = bio_list_get(&rbio->bio_list); |
|
struct bio *extra; |
|
|
|
if (rbio->generic_bio_cnt) |
|
btrfs_bio_counter_sub(rbio->fs_info, rbio->generic_bio_cnt); |
|
|
|
/* |
|
* At this moment, rbio->bio_list is empty, however since rbio does not |
|
* always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the |
|
* hash list, rbio may be merged with others so that rbio->bio_list |
|
* becomes non-empty. |
|
* Once unlock_stripe() is done, rbio->bio_list will not be updated any |
|
* more and we can call bio_endio() on all queued bios. |
|
*/ |
|
unlock_stripe(rbio); |
|
extra = bio_list_get(&rbio->bio_list); |
|
__free_raid_bio(rbio); |
|
|
|
rbio_endio_bio_list(cur, err); |
|
if (extra) |
|
rbio_endio_bio_list(extra, err); |
|
} |
|
|
|
/* |
|
* end io function used by finish_rmw. When we finally |
|
* get here, we've written a full stripe |
|
*/ |
|
static void raid_write_end_io(struct bio *bio) |
|
{ |
|
struct btrfs_raid_bio *rbio = bio->bi_private; |
|
blk_status_t err = bio->bi_status; |
|
int max_errors; |
|
|
|
if (err) |
|
fail_bio_stripe(rbio, bio); |
|
|
|
bio_put(bio); |
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending)) |
|
return; |
|
|
|
err = BLK_STS_OK; |
|
|
|
/* OK, we have read all the stripes we need to. */ |
|
max_errors = (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) ? |
|
0 : rbio->bbio->max_errors; |
|
if (atomic_read(&rbio->error) > max_errors) |
|
err = BLK_STS_IOERR; |
|
|
|
rbio_orig_end_io(rbio, err); |
|
} |
|
|
|
/* |
|
* the read/modify/write code wants to use the original bio for |
|
* any pages it included, and then use the rbio for everything |
|
* else. This function decides if a given index (stripe number) |
|
* and page number in that stripe fall inside the original bio |
|
* or the rbio. |
|
* |
|
* if you set bio_list_only, you'll get a NULL back for any ranges |
|
* that are outside the bio_list |
|
* |
|
* This doesn't take any refs on anything, you get a bare page pointer |
|
* and the caller must bump refs as required. |
|
* |
|
* You must call index_rbio_pages once before you can trust |
|
* the answers from this function. |
|
*/ |
|
static struct page *page_in_rbio(struct btrfs_raid_bio *rbio, |
|
int index, int pagenr, int bio_list_only) |
|
{ |
|
int chunk_page; |
|
struct page *p = NULL; |
|
|
|
chunk_page = index * (rbio->stripe_len >> PAGE_SHIFT) + pagenr; |
|
|
|
spin_lock_irq(&rbio->bio_list_lock); |
|
p = rbio->bio_pages[chunk_page]; |
|
spin_unlock_irq(&rbio->bio_list_lock); |
|
|
|
if (p || bio_list_only) |
|
return p; |
|
|
|
return rbio->stripe_pages[chunk_page]; |
|
} |
|
|
|
/* |
|
* number of pages we need for the entire stripe across all the |
|
* drives |
|
*/ |
|
static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes) |
|
{ |
|
return DIV_ROUND_UP(stripe_len, PAGE_SIZE) * nr_stripes; |
|
} |
|
|
|
/* |
|
* allocation and initial setup for the btrfs_raid_bio. Not |
|
* this does not allocate any pages for rbio->pages. |
|
*/ |
|
static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info, |
|
struct btrfs_bio *bbio, |
|
u64 stripe_len) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
int nr_data = 0; |
|
int real_stripes = bbio->num_stripes - bbio->num_tgtdevs; |
|
int num_pages = rbio_nr_pages(stripe_len, real_stripes); |
|
int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE); |
|
void *p; |
|
|
|
rbio = kzalloc(sizeof(*rbio) + |
|
sizeof(*rbio->stripe_pages) * num_pages + |
|
sizeof(*rbio->bio_pages) * num_pages + |
|
sizeof(*rbio->finish_pointers) * real_stripes + |
|
sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_npages) + |
|
sizeof(*rbio->finish_pbitmap) * |
|
BITS_TO_LONGS(stripe_npages), |
|
GFP_NOFS); |
|
if (!rbio) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
bio_list_init(&rbio->bio_list); |
|
INIT_LIST_HEAD(&rbio->plug_list); |
|
spin_lock_init(&rbio->bio_list_lock); |
|
INIT_LIST_HEAD(&rbio->stripe_cache); |
|
INIT_LIST_HEAD(&rbio->hash_list); |
|
rbio->bbio = bbio; |
|
rbio->fs_info = fs_info; |
|
rbio->stripe_len = stripe_len; |
|
rbio->nr_pages = num_pages; |
|
rbio->real_stripes = real_stripes; |
|
rbio->stripe_npages = stripe_npages; |
|
rbio->faila = -1; |
|
rbio->failb = -1; |
|
refcount_set(&rbio->refs, 1); |
|
atomic_set(&rbio->error, 0); |
|
atomic_set(&rbio->stripes_pending, 0); |
|
|
|
/* |
|
* the stripe_pages, bio_pages, etc arrays point to the extra |
|
* memory we allocated past the end of the rbio |
|
*/ |
|
p = rbio + 1; |
|
#define CONSUME_ALLOC(ptr, count) do { \ |
|
ptr = p; \ |
|
p = (unsigned char *)p + sizeof(*(ptr)) * (count); \ |
|
} while (0) |
|
CONSUME_ALLOC(rbio->stripe_pages, num_pages); |
|
CONSUME_ALLOC(rbio->bio_pages, num_pages); |
|
CONSUME_ALLOC(rbio->finish_pointers, real_stripes); |
|
CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_npages)); |
|
CONSUME_ALLOC(rbio->finish_pbitmap, BITS_TO_LONGS(stripe_npages)); |
|
#undef CONSUME_ALLOC |
|
|
|
if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5) |
|
nr_data = real_stripes - 1; |
|
else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) |
|
nr_data = real_stripes - 2; |
|
else |
|
BUG(); |
|
|
|
rbio->nr_data = nr_data; |
|
return rbio; |
|
} |
|
|
|
/* allocate pages for all the stripes in the bio, including parity */ |
|
static int alloc_rbio_pages(struct btrfs_raid_bio *rbio) |
|
{ |
|
int i; |
|
struct page *page; |
|
|
|
for (i = 0; i < rbio->nr_pages; i++) { |
|
if (rbio->stripe_pages[i]) |
|
continue; |
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
|
if (!page) |
|
return -ENOMEM; |
|
rbio->stripe_pages[i] = page; |
|
} |
|
return 0; |
|
} |
|
|
|
/* only allocate pages for p/q stripes */ |
|
static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio) |
|
{ |
|
int i; |
|
struct page *page; |
|
|
|
i = rbio_stripe_page_index(rbio, rbio->nr_data, 0); |
|
|
|
for (; i < rbio->nr_pages; i++) { |
|
if (rbio->stripe_pages[i]) |
|
continue; |
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
|
if (!page) |
|
return -ENOMEM; |
|
rbio->stripe_pages[i] = page; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* add a single page from a specific stripe into our list of bios for IO |
|
* this will try to merge into existing bios if possible, and returns |
|
* zero if all went well. |
|
*/ |
|
static int rbio_add_io_page(struct btrfs_raid_bio *rbio, |
|
struct bio_list *bio_list, |
|
struct page *page, |
|
int stripe_nr, |
|
unsigned long page_index, |
|
unsigned long bio_max_len) |
|
{ |
|
struct bio *last = bio_list->tail; |
|
int ret; |
|
struct bio *bio; |
|
struct btrfs_bio_stripe *stripe; |
|
u64 disk_start; |
|
|
|
stripe = &rbio->bbio->stripes[stripe_nr]; |
|
disk_start = stripe->physical + (page_index << PAGE_SHIFT); |
|
|
|
/* if the device is missing, just fail this stripe */ |
|
if (!stripe->dev->bdev) |
|
return fail_rbio_index(rbio, stripe_nr); |
|
|
|
/* see if we can add this page onto our existing bio */ |
|
if (last) { |
|
u64 last_end = (u64)last->bi_iter.bi_sector << 9; |
|
last_end += last->bi_iter.bi_size; |
|
|
|
/* |
|
* we can't merge these if they are from different |
|
* devices or if they are not contiguous |
|
*/ |
|
if (last_end == disk_start && !last->bi_status && |
|
last->bi_disk == stripe->dev->bdev->bd_disk && |
|
last->bi_partno == stripe->dev->bdev->bd_partno) { |
|
ret = bio_add_page(last, page, PAGE_SIZE, 0); |
|
if (ret == PAGE_SIZE) |
|
return 0; |
|
} |
|
} |
|
|
|
/* put a new bio on the list */ |
|
bio = btrfs_io_bio_alloc(bio_max_len >> PAGE_SHIFT ?: 1); |
|
btrfs_io_bio(bio)->device = stripe->dev; |
|
bio->bi_iter.bi_size = 0; |
|
bio_set_dev(bio, stripe->dev->bdev); |
|
bio->bi_iter.bi_sector = disk_start >> 9; |
|
|
|
bio_add_page(bio, page, PAGE_SIZE, 0); |
|
bio_list_add(bio_list, bio); |
|
return 0; |
|
} |
|
|
|
/* |
|
* while we're doing the read/modify/write cycle, we could |
|
* have errors in reading pages off the disk. This checks |
|
* for errors and if we're not able to read the page it'll |
|
* trigger parity reconstruction. The rmw will be finished |
|
* after we've reconstructed the failed stripes |
|
*/ |
|
static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio) |
|
{ |
|
if (rbio->faila >= 0 || rbio->failb >= 0) { |
|
BUG_ON(rbio->faila == rbio->real_stripes - 1); |
|
__raid56_parity_recover(rbio); |
|
} else { |
|
finish_rmw(rbio); |
|
} |
|
} |
|
|
|
/* |
|
* helper function to walk our bio list and populate the bio_pages array with |
|
* the result. This seems expensive, but it is faster than constantly |
|
* searching through the bio list as we setup the IO in finish_rmw or stripe |
|
* reconstruction. |
|
* |
|
* This must be called before you trust the answers from page_in_rbio |
|
*/ |
|
static void index_rbio_pages(struct btrfs_raid_bio *rbio) |
|
{ |
|
struct bio *bio; |
|
u64 start; |
|
unsigned long stripe_offset; |
|
unsigned long page_index; |
|
|
|
spin_lock_irq(&rbio->bio_list_lock); |
|
bio_list_for_each(bio, &rbio->bio_list) { |
|
struct bio_vec bvec; |
|
struct bvec_iter iter; |
|
int i = 0; |
|
|
|
start = (u64)bio->bi_iter.bi_sector << 9; |
|
stripe_offset = start - rbio->bbio->raid_map[0]; |
|
page_index = stripe_offset >> PAGE_SHIFT; |
|
|
|
if (bio_flagged(bio, BIO_CLONED)) |
|
bio->bi_iter = btrfs_io_bio(bio)->iter; |
|
|
|
bio_for_each_segment(bvec, bio, iter) { |
|
rbio->bio_pages[page_index + i] = bvec.bv_page; |
|
i++; |
|
} |
|
} |
|
spin_unlock_irq(&rbio->bio_list_lock); |
|
} |
|
|
|
/* |
|
* this is called from one of two situations. We either |
|
* have a full stripe from the higher layers, or we've read all |
|
* the missing bits off disk. |
|
* |
|
* This will calculate the parity and then send down any |
|
* changed blocks. |
|
*/ |
|
static noinline void finish_rmw(struct btrfs_raid_bio *rbio) |
|
{ |
|
struct btrfs_bio *bbio = rbio->bbio; |
|
void **pointers = rbio->finish_pointers; |
|
int nr_data = rbio->nr_data; |
|
int stripe; |
|
int pagenr; |
|
bool has_qstripe; |
|
struct bio_list bio_list; |
|
struct bio *bio; |
|
int ret; |
|
|
|
bio_list_init(&bio_list); |
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1) |
|
has_qstripe = false; |
|
else if (rbio->real_stripes - rbio->nr_data == 2) |
|
has_qstripe = true; |
|
else |
|
BUG(); |
|
|
|
/* at this point we either have a full stripe, |
|
* or we've read the full stripe from the drive. |
|
* recalculate the parity and write the new results. |
|
* |
|
* We're not allowed to add any new bios to the |
|
* bio list here, anyone else that wants to |
|
* change this stripe needs to do their own rmw. |
|
*/ |
|
spin_lock_irq(&rbio->bio_list_lock); |
|
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
|
spin_unlock_irq(&rbio->bio_list_lock); |
|
|
|
atomic_set(&rbio->error, 0); |
|
|
|
/* |
|
* now that we've set rmw_locked, run through the |
|
* bio list one last time and map the page pointers |
|
* |
|
* We don't cache full rbios because we're assuming |
|
* the higher layers are unlikely to use this area of |
|
* the disk again soon. If they do use it again, |
|
* hopefully they will send another full bio. |
|
*/ |
|
index_rbio_pages(rbio); |
|
if (!rbio_is_full(rbio)) |
|
cache_rbio_pages(rbio); |
|
else |
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
struct page *p; |
|
/* first collect one page from each data stripe */ |
|
for (stripe = 0; stripe < nr_data; stripe++) { |
|
p = page_in_rbio(rbio, stripe, pagenr, 0); |
|
pointers[stripe] = kmap(p); |
|
} |
|
|
|
/* then add the parity stripe */ |
|
p = rbio_pstripe_page(rbio, pagenr); |
|
SetPageUptodate(p); |
|
pointers[stripe++] = kmap(p); |
|
|
|
if (has_qstripe) { |
|
|
|
/* |
|
* raid6, add the qstripe and call the |
|
* library function to fill in our p/q |
|
*/ |
|
p = rbio_qstripe_page(rbio, pagenr); |
|
SetPageUptodate(p); |
|
pointers[stripe++] = kmap(p); |
|
|
|
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE, |
|
pointers); |
|
} else { |
|
/* raid5 */ |
|
copy_page(pointers[nr_data], pointers[0]); |
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE); |
|
} |
|
|
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) |
|
kunmap(page_in_rbio(rbio, stripe, pagenr, 0)); |
|
} |
|
|
|
/* |
|
* time to start writing. Make bios for everything from the |
|
* higher layers (the bio_list in our rbio) and our p/q. Ignore |
|
* everything else. |
|
*/ |
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
struct page *page; |
|
if (stripe < rbio->nr_data) { |
|
page = page_in_rbio(rbio, stripe, pagenr, 1); |
|
if (!page) |
|
continue; |
|
} else { |
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
} |
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, |
|
page, stripe, pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
} |
|
|
|
if (likely(!bbio->num_tgtdevs)) |
|
goto write_data; |
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
if (!bbio->tgtdev_map[stripe]) |
|
continue; |
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
struct page *page; |
|
if (stripe < rbio->nr_data) { |
|
page = page_in_rbio(rbio, stripe, pagenr, 1); |
|
if (!page) |
|
continue; |
|
} else { |
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
} |
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page, |
|
rbio->bbio->tgtdev_map[stripe], |
|
pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
} |
|
|
|
write_data: |
|
atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list)); |
|
BUG_ON(atomic_read(&rbio->stripes_pending) == 0); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) { |
|
bio->bi_private = rbio; |
|
bio->bi_end_io = raid_write_end_io; |
|
bio->bi_opf = REQ_OP_WRITE; |
|
|
|
submit_bio(bio); |
|
} |
|
return; |
|
|
|
cleanup: |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) |
|
bio_put(bio); |
|
} |
|
|
|
/* |
|
* helper to find the stripe number for a given bio. Used to figure out which |
|
* stripe has failed. This expects the bio to correspond to a physical disk, |
|
* so it looks up based on physical sector numbers. |
|
*/ |
|
static int find_bio_stripe(struct btrfs_raid_bio *rbio, |
|
struct bio *bio) |
|
{ |
|
u64 physical = bio->bi_iter.bi_sector; |
|
int i; |
|
struct btrfs_bio_stripe *stripe; |
|
|
|
physical <<= 9; |
|
|
|
for (i = 0; i < rbio->bbio->num_stripes; i++) { |
|
stripe = &rbio->bbio->stripes[i]; |
|
if (in_range(physical, stripe->physical, rbio->stripe_len) && |
|
stripe->dev->bdev && |
|
bio->bi_disk == stripe->dev->bdev->bd_disk && |
|
bio->bi_partno == stripe->dev->bdev->bd_partno) { |
|
return i; |
|
} |
|
} |
|
return -1; |
|
} |
|
|
|
/* |
|
* helper to find the stripe number for a given |
|
* bio (before mapping). Used to figure out which stripe has |
|
* failed. This looks up based on logical block numbers. |
|
*/ |
|
static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio, |
|
struct bio *bio) |
|
{ |
|
u64 logical = (u64)bio->bi_iter.bi_sector << 9; |
|
int i; |
|
|
|
for (i = 0; i < rbio->nr_data; i++) { |
|
u64 stripe_start = rbio->bbio->raid_map[i]; |
|
|
|
if (in_range(logical, stripe_start, rbio->stripe_len)) |
|
return i; |
|
} |
|
return -1; |
|
} |
|
|
|
/* |
|
* returns -EIO if we had too many failures |
|
*/ |
|
static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed) |
|
{ |
|
unsigned long flags; |
|
int ret = 0; |
|
|
|
spin_lock_irqsave(&rbio->bio_list_lock, flags); |
|
|
|
/* we already know this stripe is bad, move on */ |
|
if (rbio->faila == failed || rbio->failb == failed) |
|
goto out; |
|
|
|
if (rbio->faila == -1) { |
|
/* first failure on this rbio */ |
|
rbio->faila = failed; |
|
atomic_inc(&rbio->error); |
|
} else if (rbio->failb == -1) { |
|
/* second failure on this rbio */ |
|
rbio->failb = failed; |
|
atomic_inc(&rbio->error); |
|
} else { |
|
ret = -EIO; |
|
} |
|
out: |
|
spin_unlock_irqrestore(&rbio->bio_list_lock, flags); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to fail a stripe based on a physical disk |
|
* bio. |
|
*/ |
|
static int fail_bio_stripe(struct btrfs_raid_bio *rbio, |
|
struct bio *bio) |
|
{ |
|
int failed = find_bio_stripe(rbio, bio); |
|
|
|
if (failed < 0) |
|
return -EIO; |
|
|
|
return fail_rbio_index(rbio, failed); |
|
} |
|
|
|
/* |
|
* this sets each page in the bio uptodate. It should only be used on private |
|
* rbio pages, nothing that comes in from the higher layers |
|
*/ |
|
static void set_bio_pages_uptodate(struct bio *bio) |
|
{ |
|
struct bio_vec *bvec; |
|
struct bvec_iter_all iter_all; |
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED)); |
|
|
|
bio_for_each_segment_all(bvec, bio, iter_all) |
|
SetPageUptodate(bvec->bv_page); |
|
} |
|
|
|
/* |
|
* end io for the read phase of the rmw cycle. All the bios here are physical |
|
* stripe bios we've read from the disk so we can recalculate the parity of the |
|
* stripe. |
|
* |
|
* This will usually kick off finish_rmw once all the bios are read in, but it |
|
* may trigger parity reconstruction if we had any errors along the way |
|
*/ |
|
static void raid_rmw_end_io(struct bio *bio) |
|
{ |
|
struct btrfs_raid_bio *rbio = bio->bi_private; |
|
|
|
if (bio->bi_status) |
|
fail_bio_stripe(rbio, bio); |
|
else |
|
set_bio_pages_uptodate(bio); |
|
|
|
bio_put(bio); |
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending)) |
|
return; |
|
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors) |
|
goto cleanup; |
|
|
|
/* |
|
* this will normally call finish_rmw to start our write |
|
* but if there are any failed stripes we'll reconstruct |
|
* from parity first |
|
*/ |
|
validate_rbio_for_rmw(rbio); |
|
return; |
|
|
|
cleanup: |
|
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
} |
|
|
|
/* |
|
* the stripe must be locked by the caller. It will |
|
* unlock after all the writes are done |
|
*/ |
|
static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio) |
|
{ |
|
int bios_to_read = 0; |
|
struct bio_list bio_list; |
|
int ret; |
|
int pagenr; |
|
int stripe; |
|
struct bio *bio; |
|
|
|
bio_list_init(&bio_list); |
|
|
|
ret = alloc_rbio_pages(rbio); |
|
if (ret) |
|
goto cleanup; |
|
|
|
index_rbio_pages(rbio); |
|
|
|
atomic_set(&rbio->error, 0); |
|
/* |
|
* build a list of bios to read all the missing parts of this |
|
* stripe |
|
*/ |
|
for (stripe = 0; stripe < rbio->nr_data; stripe++) { |
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
struct page *page; |
|
/* |
|
* we want to find all the pages missing from |
|
* the rbio and read them from the disk. If |
|
* page_in_rbio finds a page in the bio list |
|
* we don't need to read it off the stripe. |
|
*/ |
|
page = page_in_rbio(rbio, stripe, pagenr, 1); |
|
if (page) |
|
continue; |
|
|
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
/* |
|
* the bio cache may have handed us an uptodate |
|
* page. If so, be happy and use it |
|
*/ |
|
if (PageUptodate(page)) |
|
continue; |
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page, |
|
stripe, pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
} |
|
|
|
bios_to_read = bio_list_size(&bio_list); |
|
if (!bios_to_read) { |
|
/* |
|
* this can happen if others have merged with |
|
* us, it means there is nothing left to read. |
|
* But if there are missing devices it may not be |
|
* safe to do the full stripe write yet. |
|
*/ |
|
goto finish; |
|
} |
|
|
|
/* |
|
* the bbio may be freed once we submit the last bio. Make sure |
|
* not to touch it after that |
|
*/ |
|
atomic_set(&rbio->stripes_pending, bios_to_read); |
|
while ((bio = bio_list_pop(&bio_list))) { |
|
bio->bi_private = rbio; |
|
bio->bi_end_io = raid_rmw_end_io; |
|
bio->bi_opf = REQ_OP_READ; |
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); |
|
|
|
submit_bio(bio); |
|
} |
|
/* the actual write will happen once the reads are done */ |
|
return 0; |
|
|
|
cleanup: |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) |
|
bio_put(bio); |
|
|
|
return -EIO; |
|
|
|
finish: |
|
validate_rbio_for_rmw(rbio); |
|
return 0; |
|
} |
|
|
|
/* |
|
* if the upper layers pass in a full stripe, we thank them by only allocating |
|
* enough pages to hold the parity, and sending it all down quickly. |
|
*/ |
|
static int full_stripe_write(struct btrfs_raid_bio *rbio) |
|
{ |
|
int ret; |
|
|
|
ret = alloc_rbio_parity_pages(rbio); |
|
if (ret) { |
|
__free_raid_bio(rbio); |
|
return ret; |
|
} |
|
|
|
ret = lock_stripe_add(rbio); |
|
if (ret == 0) |
|
finish_rmw(rbio); |
|
return 0; |
|
} |
|
|
|
/* |
|
* partial stripe writes get handed over to async helpers. |
|
* We're really hoping to merge a few more writes into this |
|
* rbio before calculating new parity |
|
*/ |
|
static int partial_stripe_write(struct btrfs_raid_bio *rbio) |
|
{ |
|
int ret; |
|
|
|
ret = lock_stripe_add(rbio); |
|
if (ret == 0) |
|
start_async_work(rbio, rmw_work); |
|
return 0; |
|
} |
|
|
|
/* |
|
* sometimes while we were reading from the drive to |
|
* recalculate parity, enough new bios come into create |
|
* a full stripe. So we do a check here to see if we can |
|
* go directly to finish_rmw |
|
*/ |
|
static int __raid56_parity_write(struct btrfs_raid_bio *rbio) |
|
{ |
|
/* head off into rmw land if we don't have a full stripe */ |
|
if (!rbio_is_full(rbio)) |
|
return partial_stripe_write(rbio); |
|
return full_stripe_write(rbio); |
|
} |
|
|
|
/* |
|
* We use plugging call backs to collect full stripes. |
|
* Any time we get a partial stripe write while plugged |
|
* we collect it into a list. When the unplug comes down, |
|
* we sort the list by logical block number and merge |
|
* everything we can into the same rbios |
|
*/ |
|
struct btrfs_plug_cb { |
|
struct blk_plug_cb cb; |
|
struct btrfs_fs_info *info; |
|
struct list_head rbio_list; |
|
struct btrfs_work work; |
|
}; |
|
|
|
/* |
|
* rbios on the plug list are sorted for easier merging. |
|
*/ |
|
static int plug_cmp(void *priv, struct list_head *a, struct list_head *b) |
|
{ |
|
struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio, |
|
plug_list); |
|
struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio, |
|
plug_list); |
|
u64 a_sector = ra->bio_list.head->bi_iter.bi_sector; |
|
u64 b_sector = rb->bio_list.head->bi_iter.bi_sector; |
|
|
|
if (a_sector < b_sector) |
|
return -1; |
|
if (a_sector > b_sector) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static void run_plug(struct btrfs_plug_cb *plug) |
|
{ |
|
struct btrfs_raid_bio *cur; |
|
struct btrfs_raid_bio *last = NULL; |
|
|
|
/* |
|
* sort our plug list then try to merge |
|
* everything we can in hopes of creating full |
|
* stripes. |
|
*/ |
|
list_sort(NULL, &plug->rbio_list, plug_cmp); |
|
while (!list_empty(&plug->rbio_list)) { |
|
cur = list_entry(plug->rbio_list.next, |
|
struct btrfs_raid_bio, plug_list); |
|
list_del_init(&cur->plug_list); |
|
|
|
if (rbio_is_full(cur)) { |
|
int ret; |
|
|
|
/* we have a full stripe, send it down */ |
|
ret = full_stripe_write(cur); |
|
BUG_ON(ret); |
|
continue; |
|
} |
|
if (last) { |
|
if (rbio_can_merge(last, cur)) { |
|
merge_rbio(last, cur); |
|
__free_raid_bio(cur); |
|
continue; |
|
|
|
} |
|
__raid56_parity_write(last); |
|
} |
|
last = cur; |
|
} |
|
if (last) { |
|
__raid56_parity_write(last); |
|
} |
|
kfree(plug); |
|
} |
|
|
|
/* |
|
* if the unplug comes from schedule, we have to push the |
|
* work off to a helper thread |
|
*/ |
|
static void unplug_work(struct btrfs_work *work) |
|
{ |
|
struct btrfs_plug_cb *plug; |
|
plug = container_of(work, struct btrfs_plug_cb, work); |
|
run_plug(plug); |
|
} |
|
|
|
static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule) |
|
{ |
|
struct btrfs_plug_cb *plug; |
|
plug = container_of(cb, struct btrfs_plug_cb, cb); |
|
|
|
if (from_schedule) { |
|
btrfs_init_work(&plug->work, unplug_work, NULL, NULL); |
|
btrfs_queue_work(plug->info->rmw_workers, |
|
&plug->work); |
|
return; |
|
} |
|
run_plug(plug); |
|
} |
|
|
|
/* |
|
* our main entry point for writes from the rest of the FS. |
|
*/ |
|
int raid56_parity_write(struct btrfs_fs_info *fs_info, struct bio *bio, |
|
struct btrfs_bio *bbio, u64 stripe_len) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
struct btrfs_plug_cb *plug = NULL; |
|
struct blk_plug_cb *cb; |
|
int ret; |
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len); |
|
if (IS_ERR(rbio)) { |
|
btrfs_put_bbio(bbio); |
|
return PTR_ERR(rbio); |
|
} |
|
bio_list_add(&rbio->bio_list, bio); |
|
rbio->bio_list_bytes = bio->bi_iter.bi_size; |
|
rbio->operation = BTRFS_RBIO_WRITE; |
|
|
|
btrfs_bio_counter_inc_noblocked(fs_info); |
|
rbio->generic_bio_cnt = 1; |
|
|
|
/* |
|
* don't plug on full rbios, just get them out the door |
|
* as quickly as we can |
|
*/ |
|
if (rbio_is_full(rbio)) { |
|
ret = full_stripe_write(rbio); |
|
if (ret) |
|
btrfs_bio_counter_dec(fs_info); |
|
return ret; |
|
} |
|
|
|
cb = blk_check_plugged(btrfs_raid_unplug, fs_info, sizeof(*plug)); |
|
if (cb) { |
|
plug = container_of(cb, struct btrfs_plug_cb, cb); |
|
if (!plug->info) { |
|
plug->info = fs_info; |
|
INIT_LIST_HEAD(&plug->rbio_list); |
|
} |
|
list_add_tail(&rbio->plug_list, &plug->rbio_list); |
|
ret = 0; |
|
} else { |
|
ret = __raid56_parity_write(rbio); |
|
if (ret) |
|
btrfs_bio_counter_dec(fs_info); |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* all parity reconstruction happens here. We've read in everything |
|
* we can find from the drives and this does the heavy lifting of |
|
* sorting the good from the bad. |
|
*/ |
|
static void __raid_recover_end_io(struct btrfs_raid_bio *rbio) |
|
{ |
|
int pagenr, stripe; |
|
void **pointers; |
|
int faila = -1, failb = -1; |
|
struct page *page; |
|
blk_status_t err; |
|
int i; |
|
|
|
pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS); |
|
if (!pointers) { |
|
err = BLK_STS_RESOURCE; |
|
goto cleanup_io; |
|
} |
|
|
|
faila = rbio->faila; |
|
failb = rbio->failb; |
|
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD || |
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) { |
|
spin_lock_irq(&rbio->bio_list_lock); |
|
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
|
spin_unlock_irq(&rbio->bio_list_lock); |
|
} |
|
|
|
index_rbio_pages(rbio); |
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
/* |
|
* Now we just use bitmap to mark the horizontal stripes in |
|
* which we have data when doing parity scrub. |
|
*/ |
|
if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB && |
|
!test_bit(pagenr, rbio->dbitmap)) |
|
continue; |
|
|
|
/* setup our array of pointers with pages |
|
* from each stripe |
|
*/ |
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
/* |
|
* if we're rebuilding a read, we have to use |
|
* pages from the bio list |
|
*/ |
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD || |
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) && |
|
(stripe == faila || stripe == failb)) { |
|
page = page_in_rbio(rbio, stripe, pagenr, 0); |
|
} else { |
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
} |
|
pointers[stripe] = kmap(page); |
|
} |
|
|
|
/* all raid6 handling here */ |
|
if (rbio->bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) { |
|
/* |
|
* single failure, rebuild from parity raid5 |
|
* style |
|
*/ |
|
if (failb < 0) { |
|
if (faila == rbio->nr_data) { |
|
/* |
|
* Just the P stripe has failed, without |
|
* a bad data or Q stripe. |
|
* TODO, we should redo the xor here. |
|
*/ |
|
err = BLK_STS_IOERR; |
|
goto cleanup; |
|
} |
|
/* |
|
* a single failure in raid6 is rebuilt |
|
* in the pstripe code below |
|
*/ |
|
goto pstripe; |
|
} |
|
|
|
/* make sure our ps and qs are in order */ |
|
if (faila > failb) |
|
swap(faila, failb); |
|
|
|
/* if the q stripe is failed, do a pstripe reconstruction |
|
* from the xors. |
|
* If both the q stripe and the P stripe are failed, we're |
|
* here due to a crc mismatch and we can't give them the |
|
* data they want |
|
*/ |
|
if (rbio->bbio->raid_map[failb] == RAID6_Q_STRIPE) { |
|
if (rbio->bbio->raid_map[faila] == |
|
RAID5_P_STRIPE) { |
|
err = BLK_STS_IOERR; |
|
goto cleanup; |
|
} |
|
/* |
|
* otherwise we have one bad data stripe and |
|
* a good P stripe. raid5! |
|
*/ |
|
goto pstripe; |
|
} |
|
|
|
if (rbio->bbio->raid_map[failb] == RAID5_P_STRIPE) { |
|
raid6_datap_recov(rbio->real_stripes, |
|
PAGE_SIZE, faila, pointers); |
|
} else { |
|
raid6_2data_recov(rbio->real_stripes, |
|
PAGE_SIZE, faila, failb, |
|
pointers); |
|
} |
|
} else { |
|
void *p; |
|
|
|
/* rebuild from P stripe here (raid5 or raid6) */ |
|
BUG_ON(failb != -1); |
|
pstripe: |
|
/* Copy parity block into failed block to start with */ |
|
copy_page(pointers[faila], pointers[rbio->nr_data]); |
|
|
|
/* rearrange the pointer array */ |
|
p = pointers[faila]; |
|
for (stripe = faila; stripe < rbio->nr_data - 1; stripe++) |
|
pointers[stripe] = pointers[stripe + 1]; |
|
pointers[rbio->nr_data - 1] = p; |
|
|
|
/* xor in the rest */ |
|
run_xor(pointers, rbio->nr_data - 1, PAGE_SIZE); |
|
} |
|
/* if we're doing this rebuild as part of an rmw, go through |
|
* and set all of our private rbio pages in the |
|
* failed stripes as uptodate. This way finish_rmw will |
|
* know they can be trusted. If this was a read reconstruction, |
|
* other endio functions will fiddle the uptodate bits |
|
*/ |
|
if (rbio->operation == BTRFS_RBIO_WRITE) { |
|
for (i = 0; i < rbio->stripe_npages; i++) { |
|
if (faila != -1) { |
|
page = rbio_stripe_page(rbio, faila, i); |
|
SetPageUptodate(page); |
|
} |
|
if (failb != -1) { |
|
page = rbio_stripe_page(rbio, failb, i); |
|
SetPageUptodate(page); |
|
} |
|
} |
|
} |
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
/* |
|
* if we're rebuilding a read, we have to use |
|
* pages from the bio list |
|
*/ |
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD || |
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) && |
|
(stripe == faila || stripe == failb)) { |
|
page = page_in_rbio(rbio, stripe, pagenr, 0); |
|
} else { |
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
} |
|
kunmap(page); |
|
} |
|
} |
|
|
|
err = BLK_STS_OK; |
|
cleanup: |
|
kfree(pointers); |
|
|
|
cleanup_io: |
|
/* |
|
* Similar to READ_REBUILD, REBUILD_MISSING at this point also has a |
|
* valid rbio which is consistent with ondisk content, thus such a |
|
* valid rbio can be cached to avoid further disk reads. |
|
*/ |
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD || |
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) { |
|
/* |
|
* - In case of two failures, where rbio->failb != -1: |
|
* |
|
* Do not cache this rbio since the above read reconstruction |
|
* (raid6_datap_recov() or raid6_2data_recov()) may have |
|
* changed some content of stripes which are not identical to |
|
* on-disk content any more, otherwise, a later write/recover |
|
* may steal stripe_pages from this rbio and end up with |
|
* corruptions or rebuild failures. |
|
* |
|
* - In case of single failure, where rbio->failb == -1: |
|
* |
|
* Cache this rbio iff the above read reconstruction is |
|
* executed without problems. |
|
*/ |
|
if (err == BLK_STS_OK && rbio->failb < 0) |
|
cache_rbio_pages(rbio); |
|
else |
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
|
|
|
rbio_orig_end_io(rbio, err); |
|
} else if (err == BLK_STS_OK) { |
|
rbio->faila = -1; |
|
rbio->failb = -1; |
|
|
|
if (rbio->operation == BTRFS_RBIO_WRITE) |
|
finish_rmw(rbio); |
|
else if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) |
|
finish_parity_scrub(rbio, 0); |
|
else |
|
BUG(); |
|
} else { |
|
rbio_orig_end_io(rbio, err); |
|
} |
|
} |
|
|
|
/* |
|
* This is called only for stripes we've read from disk to |
|
* reconstruct the parity. |
|
*/ |
|
static void raid_recover_end_io(struct bio *bio) |
|
{ |
|
struct btrfs_raid_bio *rbio = bio->bi_private; |
|
|
|
/* |
|
* we only read stripe pages off the disk, set them |
|
* up to date if there were no errors |
|
*/ |
|
if (bio->bi_status) |
|
fail_bio_stripe(rbio, bio); |
|
else |
|
set_bio_pages_uptodate(bio); |
|
bio_put(bio); |
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending)) |
|
return; |
|
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors) |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
else |
|
__raid_recover_end_io(rbio); |
|
} |
|
|
|
/* |
|
* reads everything we need off the disk to reconstruct |
|
* the parity. endio handlers trigger final reconstruction |
|
* when the IO is done. |
|
* |
|
* This is used both for reads from the higher layers and for |
|
* parity construction required to finish a rmw cycle. |
|
*/ |
|
static int __raid56_parity_recover(struct btrfs_raid_bio *rbio) |
|
{ |
|
int bios_to_read = 0; |
|
struct bio_list bio_list; |
|
int ret; |
|
int pagenr; |
|
int stripe; |
|
struct bio *bio; |
|
|
|
bio_list_init(&bio_list); |
|
|
|
ret = alloc_rbio_pages(rbio); |
|
if (ret) |
|
goto cleanup; |
|
|
|
atomic_set(&rbio->error, 0); |
|
|
|
/* |
|
* read everything that hasn't failed. Thanks to the |
|
* stripe cache, it is possible that some or all of these |
|
* pages are going to be uptodate. |
|
*/ |
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
if (rbio->faila == stripe || rbio->failb == stripe) { |
|
atomic_inc(&rbio->error); |
|
continue; |
|
} |
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) { |
|
struct page *p; |
|
|
|
/* |
|
* the rmw code may have already read this |
|
* page in |
|
*/ |
|
p = rbio_stripe_page(rbio, stripe, pagenr); |
|
if (PageUptodate(p)) |
|
continue; |
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, |
|
rbio_stripe_page(rbio, stripe, pagenr), |
|
stripe, pagenr, rbio->stripe_len); |
|
if (ret < 0) |
|
goto cleanup; |
|
} |
|
} |
|
|
|
bios_to_read = bio_list_size(&bio_list); |
|
if (!bios_to_read) { |
|
/* |
|
* we might have no bios to read just because the pages |
|
* were up to date, or we might have no bios to read because |
|
* the devices were gone. |
|
*/ |
|
if (atomic_read(&rbio->error) <= rbio->bbio->max_errors) { |
|
__raid_recover_end_io(rbio); |
|
return 0; |
|
} else { |
|
goto cleanup; |
|
} |
|
} |
|
|
|
/* |
|
* the bbio may be freed once we submit the last bio. Make sure |
|
* not to touch it after that |
|
*/ |
|
atomic_set(&rbio->stripes_pending, bios_to_read); |
|
while ((bio = bio_list_pop(&bio_list))) { |
|
bio->bi_private = rbio; |
|
bio->bi_end_io = raid_recover_end_io; |
|
bio->bi_opf = REQ_OP_READ; |
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); |
|
|
|
submit_bio(bio); |
|
} |
|
|
|
return 0; |
|
|
|
cleanup: |
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD || |
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) |
|
bio_put(bio); |
|
|
|
return -EIO; |
|
} |
|
|
|
/* |
|
* the main entry point for reads from the higher layers. This |
|
* is really only called when the normal read path had a failure, |
|
* so we assume the bio they send down corresponds to a failed part |
|
* of the drive. |
|
*/ |
|
int raid56_parity_recover(struct btrfs_fs_info *fs_info, struct bio *bio, |
|
struct btrfs_bio *bbio, u64 stripe_len, |
|
int mirror_num, int generic_io) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
int ret; |
|
|
|
if (generic_io) { |
|
ASSERT(bbio->mirror_num == mirror_num); |
|
btrfs_io_bio(bio)->mirror_num = mirror_num; |
|
} |
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len); |
|
if (IS_ERR(rbio)) { |
|
if (generic_io) |
|
btrfs_put_bbio(bbio); |
|
return PTR_ERR(rbio); |
|
} |
|
|
|
rbio->operation = BTRFS_RBIO_READ_REBUILD; |
|
bio_list_add(&rbio->bio_list, bio); |
|
rbio->bio_list_bytes = bio->bi_iter.bi_size; |
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio); |
|
if (rbio->faila == -1) { |
|
btrfs_warn(fs_info, |
|
"%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)", |
|
__func__, (u64)bio->bi_iter.bi_sector << 9, |
|
(u64)bio->bi_iter.bi_size, bbio->map_type); |
|
if (generic_io) |
|
btrfs_put_bbio(bbio); |
|
kfree(rbio); |
|
return -EIO; |
|
} |
|
|
|
if (generic_io) { |
|
btrfs_bio_counter_inc_noblocked(fs_info); |
|
rbio->generic_bio_cnt = 1; |
|
} else { |
|
btrfs_get_bbio(bbio); |
|
} |
|
|
|
/* |
|
* Loop retry: |
|
* for 'mirror == 2', reconstruct from all other stripes. |
|
* for 'mirror_num > 2', select a stripe to fail on every retry. |
|
*/ |
|
if (mirror_num > 2) { |
|
/* |
|
* 'mirror == 3' is to fail the p stripe and |
|
* reconstruct from the q stripe. 'mirror > 3' is to |
|
* fail a data stripe and reconstruct from p+q stripe. |
|
*/ |
|
rbio->failb = rbio->real_stripes - (mirror_num - 1); |
|
ASSERT(rbio->failb > 0); |
|
if (rbio->failb <= rbio->faila) |
|
rbio->failb--; |
|
} |
|
|
|
ret = lock_stripe_add(rbio); |
|
|
|
/* |
|
* __raid56_parity_recover will end the bio with |
|
* any errors it hits. We don't want to return |
|
* its error value up the stack because our caller |
|
* will end up calling bio_endio with any nonzero |
|
* return |
|
*/ |
|
if (ret == 0) |
|
__raid56_parity_recover(rbio); |
|
/* |
|
* our rbio has been added to the list of |
|
* rbios that will be handled after the |
|
* currently lock owner is done |
|
*/ |
|
return 0; |
|
|
|
} |
|
|
|
static void rmw_work(struct btrfs_work *work) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work); |
|
raid56_rmw_stripe(rbio); |
|
} |
|
|
|
static void read_rebuild_work(struct btrfs_work *work) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work); |
|
__raid56_parity_recover(rbio); |
|
} |
|
|
|
/* |
|
* The following code is used to scrub/replace the parity stripe |
|
* |
|
* Caller must have already increased bio_counter for getting @bbio. |
|
* |
|
* Note: We need make sure all the pages that add into the scrub/replace |
|
* raid bio are correct and not be changed during the scrub/replace. That |
|
* is those pages just hold metadata or file data with checksum. |
|
*/ |
|
|
|
struct btrfs_raid_bio * |
|
raid56_parity_alloc_scrub_rbio(struct btrfs_fs_info *fs_info, struct bio *bio, |
|
struct btrfs_bio *bbio, u64 stripe_len, |
|
struct btrfs_device *scrub_dev, |
|
unsigned long *dbitmap, int stripe_nsectors) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
int i; |
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len); |
|
if (IS_ERR(rbio)) |
|
return NULL; |
|
bio_list_add(&rbio->bio_list, bio); |
|
/* |
|
* This is a special bio which is used to hold the completion handler |
|
* and make the scrub rbio is similar to the other types |
|
*/ |
|
ASSERT(!bio->bi_iter.bi_size); |
|
rbio->operation = BTRFS_RBIO_PARITY_SCRUB; |
|
|
|
/* |
|
* After mapping bbio with BTRFS_MAP_WRITE, parities have been sorted |
|
* to the end position, so this search can start from the first parity |
|
* stripe. |
|
*/ |
|
for (i = rbio->nr_data; i < rbio->real_stripes; i++) { |
|
if (bbio->stripes[i].dev == scrub_dev) { |
|
rbio->scrubp = i; |
|
break; |
|
} |
|
} |
|
ASSERT(i < rbio->real_stripes); |
|
|
|
/* Now we just support the sectorsize equals to page size */ |
|
ASSERT(fs_info->sectorsize == PAGE_SIZE); |
|
ASSERT(rbio->stripe_npages == stripe_nsectors); |
|
bitmap_copy(rbio->dbitmap, dbitmap, stripe_nsectors); |
|
|
|
/* |
|
* We have already increased bio_counter when getting bbio, record it |
|
* so we can free it at rbio_orig_end_io(). |
|
*/ |
|
rbio->generic_bio_cnt = 1; |
|
|
|
return rbio; |
|
} |
|
|
|
/* Used for both parity scrub and missing. */ |
|
void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page, |
|
u64 logical) |
|
{ |
|
int stripe_offset; |
|
int index; |
|
|
|
ASSERT(logical >= rbio->bbio->raid_map[0]); |
|
ASSERT(logical + PAGE_SIZE <= rbio->bbio->raid_map[0] + |
|
rbio->stripe_len * rbio->nr_data); |
|
stripe_offset = (int)(logical - rbio->bbio->raid_map[0]); |
|
index = stripe_offset >> PAGE_SHIFT; |
|
rbio->bio_pages[index] = page; |
|
} |
|
|
|
/* |
|
* We just scrub the parity that we have correct data on the same horizontal, |
|
* so we needn't allocate all pages for all the stripes. |
|
*/ |
|
static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio) |
|
{ |
|
int i; |
|
int bit; |
|
int index; |
|
struct page *page; |
|
|
|
for_each_set_bit(bit, rbio->dbitmap, rbio->stripe_npages) { |
|
for (i = 0; i < rbio->real_stripes; i++) { |
|
index = i * rbio->stripe_npages + bit; |
|
if (rbio->stripe_pages[index]) |
|
continue; |
|
|
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
|
if (!page) |
|
return -ENOMEM; |
|
rbio->stripe_pages[index] = page; |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, |
|
int need_check) |
|
{ |
|
struct btrfs_bio *bbio = rbio->bbio; |
|
void **pointers = rbio->finish_pointers; |
|
unsigned long *pbitmap = rbio->finish_pbitmap; |
|
int nr_data = rbio->nr_data; |
|
int stripe; |
|
int pagenr; |
|
bool has_qstripe; |
|
struct page *p_page = NULL; |
|
struct page *q_page = NULL; |
|
struct bio_list bio_list; |
|
struct bio *bio; |
|
int is_replace = 0; |
|
int ret; |
|
|
|
bio_list_init(&bio_list); |
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1) |
|
has_qstripe = false; |
|
else if (rbio->real_stripes - rbio->nr_data == 2) |
|
has_qstripe = true; |
|
else |
|
BUG(); |
|
|
|
if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) { |
|
is_replace = 1; |
|
bitmap_copy(pbitmap, rbio->dbitmap, rbio->stripe_npages); |
|
} |
|
|
|
/* |
|
* Because the higher layers(scrubber) are unlikely to |
|
* use this area of the disk again soon, so don't cache |
|
* it. |
|
*/ |
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
|
|
|
if (!need_check) |
|
goto writeback; |
|
|
|
p_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
|
if (!p_page) |
|
goto cleanup; |
|
SetPageUptodate(p_page); |
|
|
|
if (has_qstripe) { |
|
/* RAID6, allocate and map temp space for the Q stripe */ |
|
q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
|
if (!q_page) { |
|
__free_page(p_page); |
|
goto cleanup; |
|
} |
|
SetPageUptodate(q_page); |
|
pointers[rbio->real_stripes - 1] = kmap(q_page); |
|
} |
|
|
|
atomic_set(&rbio->error, 0); |
|
|
|
/* Map the parity stripe just once */ |
|
pointers[nr_data] = kmap(p_page); |
|
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) { |
|
struct page *p; |
|
void *parity; |
|
/* first collect one page from each data stripe */ |
|
for (stripe = 0; stripe < nr_data; stripe++) { |
|
p = page_in_rbio(rbio, stripe, pagenr, 0); |
|
pointers[stripe] = kmap(p); |
|
} |
|
|
|
if (has_qstripe) { |
|
/* RAID6, call the library function to fill in our P/Q */ |
|
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE, |
|
pointers); |
|
} else { |
|
/* raid5 */ |
|
copy_page(pointers[nr_data], pointers[0]); |
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE); |
|
} |
|
|
|
/* Check scrubbing parity and repair it */ |
|
p = rbio_stripe_page(rbio, rbio->scrubp, pagenr); |
|
parity = kmap(p); |
|
if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE)) |
|
copy_page(parity, pointers[rbio->scrubp]); |
|
else |
|
/* Parity is right, needn't writeback */ |
|
bitmap_clear(rbio->dbitmap, pagenr, 1); |
|
kunmap(p); |
|
|
|
for (stripe = 0; stripe < nr_data; stripe++) |
|
kunmap(page_in_rbio(rbio, stripe, pagenr, 0)); |
|
} |
|
|
|
kunmap(p_page); |
|
__free_page(p_page); |
|
if (q_page) { |
|
kunmap(q_page); |
|
__free_page(q_page); |
|
} |
|
|
|
writeback: |
|
/* |
|
* time to start writing. Make bios for everything from the |
|
* higher layers (the bio_list in our rbio) and our p/q. Ignore |
|
* everything else. |
|
*/ |
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) { |
|
struct page *page; |
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr); |
|
ret = rbio_add_io_page(rbio, &bio_list, |
|
page, rbio->scrubp, pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
|
|
if (!is_replace) |
|
goto submit_write; |
|
|
|
for_each_set_bit(pagenr, pbitmap, rbio->stripe_npages) { |
|
struct page *page; |
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr); |
|
ret = rbio_add_io_page(rbio, &bio_list, page, |
|
bbio->tgtdev_map[rbio->scrubp], |
|
pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
|
|
submit_write: |
|
nr_data = bio_list_size(&bio_list); |
|
if (!nr_data) { |
|
/* Every parity is right */ |
|
rbio_orig_end_io(rbio, BLK_STS_OK); |
|
return; |
|
} |
|
|
|
atomic_set(&rbio->stripes_pending, nr_data); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) { |
|
bio->bi_private = rbio; |
|
bio->bi_end_io = raid_write_end_io; |
|
bio->bi_opf = REQ_OP_WRITE; |
|
|
|
submit_bio(bio); |
|
} |
|
return; |
|
|
|
cleanup: |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) |
|
bio_put(bio); |
|
} |
|
|
|
static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe) |
|
{ |
|
if (stripe >= 0 && stripe < rbio->nr_data) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/* |
|
* While we're doing the parity check and repair, we could have errors |
|
* in reading pages off the disk. This checks for errors and if we're |
|
* not able to read the page it'll trigger parity reconstruction. The |
|
* parity scrub will be finished after we've reconstructed the failed |
|
* stripes |
|
*/ |
|
static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio) |
|
{ |
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors) |
|
goto cleanup; |
|
|
|
if (rbio->faila >= 0 || rbio->failb >= 0) { |
|
int dfail = 0, failp = -1; |
|
|
|
if (is_data_stripe(rbio, rbio->faila)) |
|
dfail++; |
|
else if (is_parity_stripe(rbio->faila)) |
|
failp = rbio->faila; |
|
|
|
if (is_data_stripe(rbio, rbio->failb)) |
|
dfail++; |
|
else if (is_parity_stripe(rbio->failb)) |
|
failp = rbio->failb; |
|
|
|
/* |
|
* Because we can not use a scrubbing parity to repair |
|
* the data, so the capability of the repair is declined. |
|
* (In the case of RAID5, we can not repair anything) |
|
*/ |
|
if (dfail > rbio->bbio->max_errors - 1) |
|
goto cleanup; |
|
|
|
/* |
|
* If all data is good, only parity is correctly, just |
|
* repair the parity. |
|
*/ |
|
if (dfail == 0) { |
|
finish_parity_scrub(rbio, 0); |
|
return; |
|
} |
|
|
|
/* |
|
* Here means we got one corrupted data stripe and one |
|
* corrupted parity on RAID6, if the corrupted parity |
|
* is scrubbing parity, luckily, use the other one to repair |
|
* the data, or we can not repair the data stripe. |
|
*/ |
|
if (failp != rbio->scrubp) |
|
goto cleanup; |
|
|
|
__raid_recover_end_io(rbio); |
|
} else { |
|
finish_parity_scrub(rbio, 1); |
|
} |
|
return; |
|
|
|
cleanup: |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
} |
|
|
|
/* |
|
* end io for the read phase of the rmw cycle. All the bios here are physical |
|
* stripe bios we've read from the disk so we can recalculate the parity of the |
|
* stripe. |
|
* |
|
* This will usually kick off finish_rmw once all the bios are read in, but it |
|
* may trigger parity reconstruction if we had any errors along the way |
|
*/ |
|
static void raid56_parity_scrub_end_io(struct bio *bio) |
|
{ |
|
struct btrfs_raid_bio *rbio = bio->bi_private; |
|
|
|
if (bio->bi_status) |
|
fail_bio_stripe(rbio, bio); |
|
else |
|
set_bio_pages_uptodate(bio); |
|
|
|
bio_put(bio); |
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending)) |
|
return; |
|
|
|
/* |
|
* this will normally call finish_rmw to start our write |
|
* but if there are any failed stripes we'll reconstruct |
|
* from parity first |
|
*/ |
|
validate_rbio_for_parity_scrub(rbio); |
|
} |
|
|
|
static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio) |
|
{ |
|
int bios_to_read = 0; |
|
struct bio_list bio_list; |
|
int ret; |
|
int pagenr; |
|
int stripe; |
|
struct bio *bio; |
|
|
|
bio_list_init(&bio_list); |
|
|
|
ret = alloc_rbio_essential_pages(rbio); |
|
if (ret) |
|
goto cleanup; |
|
|
|
atomic_set(&rbio->error, 0); |
|
/* |
|
* build a list of bios to read all the missing parts of this |
|
* stripe |
|
*/ |
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) { |
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) { |
|
struct page *page; |
|
/* |
|
* we want to find all the pages missing from |
|
* the rbio and read them from the disk. If |
|
* page_in_rbio finds a page in the bio list |
|
* we don't need to read it off the stripe. |
|
*/ |
|
page = page_in_rbio(rbio, stripe, pagenr, 1); |
|
if (page) |
|
continue; |
|
|
|
page = rbio_stripe_page(rbio, stripe, pagenr); |
|
/* |
|
* the bio cache may have handed us an uptodate |
|
* page. If so, be happy and use it |
|
*/ |
|
if (PageUptodate(page)) |
|
continue; |
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page, |
|
stripe, pagenr, rbio->stripe_len); |
|
if (ret) |
|
goto cleanup; |
|
} |
|
} |
|
|
|
bios_to_read = bio_list_size(&bio_list); |
|
if (!bios_to_read) { |
|
/* |
|
* this can happen if others have merged with |
|
* us, it means there is nothing left to read. |
|
* But if there are missing devices it may not be |
|
* safe to do the full stripe write yet. |
|
*/ |
|
goto finish; |
|
} |
|
|
|
/* |
|
* the bbio may be freed once we submit the last bio. Make sure |
|
* not to touch it after that |
|
*/ |
|
atomic_set(&rbio->stripes_pending, bios_to_read); |
|
while ((bio = bio_list_pop(&bio_list))) { |
|
bio->bi_private = rbio; |
|
bio->bi_end_io = raid56_parity_scrub_end_io; |
|
bio->bi_opf = REQ_OP_READ; |
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); |
|
|
|
submit_bio(bio); |
|
} |
|
/* the actual write will happen once the reads are done */ |
|
return; |
|
|
|
cleanup: |
|
rbio_orig_end_io(rbio, BLK_STS_IOERR); |
|
|
|
while ((bio = bio_list_pop(&bio_list))) |
|
bio_put(bio); |
|
|
|
return; |
|
|
|
finish: |
|
validate_rbio_for_parity_scrub(rbio); |
|
} |
|
|
|
static void scrub_parity_work(struct btrfs_work *work) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work); |
|
raid56_parity_scrub_stripe(rbio); |
|
} |
|
|
|
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio) |
|
{ |
|
if (!lock_stripe_add(rbio)) |
|
start_async_work(rbio, scrub_parity_work); |
|
} |
|
|
|
/* The following code is used for dev replace of a missing RAID 5/6 device. */ |
|
|
|
struct btrfs_raid_bio * |
|
raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio, |
|
struct btrfs_bio *bbio, u64 length) |
|
{ |
|
struct btrfs_raid_bio *rbio; |
|
|
|
rbio = alloc_rbio(fs_info, bbio, length); |
|
if (IS_ERR(rbio)) |
|
return NULL; |
|
|
|
rbio->operation = BTRFS_RBIO_REBUILD_MISSING; |
|
bio_list_add(&rbio->bio_list, bio); |
|
/* |
|
* This is a special bio which is used to hold the completion handler |
|
* and make the scrub rbio is similar to the other types |
|
*/ |
|
ASSERT(!bio->bi_iter.bi_size); |
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio); |
|
if (rbio->faila == -1) { |
|
BUG(); |
|
kfree(rbio); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* When we get bbio, we have already increased bio_counter, record it |
|
* so we can free it at rbio_orig_end_io() |
|
*/ |
|
rbio->generic_bio_cnt = 1; |
|
|
|
return rbio; |
|
} |
|
|
|
void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio) |
|
{ |
|
if (!lock_stripe_add(rbio)) |
|
start_async_work(rbio, read_rebuild_work); |
|
}
|
|
|