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4533 lines
112 KiB
4533 lines
112 KiB
/* |
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* Copyright (C) 2011-2012 Red Hat UK. |
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* |
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* This file is released under the GPL. |
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*/ |
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|
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#include "dm-thin-metadata.h" |
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#include "dm-bio-prison-v1.h" |
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#include "dm.h" |
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|
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#include <linux/device-mapper.h> |
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#include <linux/dm-io.h> |
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#include <linux/dm-kcopyd.h> |
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#include <linux/jiffies.h> |
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#include <linux/log2.h> |
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#include <linux/list.h> |
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#include <linux/rculist.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/vmalloc.h> |
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#include <linux/sort.h> |
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#include <linux/rbtree.h> |
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|
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#define DM_MSG_PREFIX "thin" |
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|
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/* |
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* Tunable constants |
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*/ |
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#define ENDIO_HOOK_POOL_SIZE 1024 |
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#define MAPPING_POOL_SIZE 1024 |
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#define COMMIT_PERIOD HZ |
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#define NO_SPACE_TIMEOUT_SECS 60 |
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static unsigned no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS; |
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DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle, |
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"A percentage of time allocated for copy on write"); |
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|
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/* |
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* The block size of the device holding pool data must be |
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* between 64KB and 1GB. |
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*/ |
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#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT) |
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#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) |
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|
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/* |
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* Device id is restricted to 24 bits. |
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*/ |
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#define MAX_DEV_ID ((1 << 24) - 1) |
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|
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/* |
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* How do we handle breaking sharing of data blocks? |
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* ================================================= |
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* |
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* We use a standard copy-on-write btree to store the mappings for the |
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* devices (note I'm talking about copy-on-write of the metadata here, not |
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* the data). When you take an internal snapshot you clone the root node |
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* of the origin btree. After this there is no concept of an origin or a |
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* snapshot. They are just two device trees that happen to point to the |
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* same data blocks. |
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* |
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* When we get a write in we decide if it's to a shared data block using |
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* some timestamp magic. If it is, we have to break sharing. |
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* |
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* Let's say we write to a shared block in what was the origin. The |
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* steps are: |
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* |
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* i) plug io further to this physical block. (see bio_prison code). |
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* |
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* ii) quiesce any read io to that shared data block. Obviously |
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* including all devices that share this block. (see dm_deferred_set code) |
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* |
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* iii) copy the data block to a newly allocate block. This step can be |
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* missed out if the io covers the block. (schedule_copy). |
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* |
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* iv) insert the new mapping into the origin's btree |
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* (process_prepared_mapping). This act of inserting breaks some |
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* sharing of btree nodes between the two devices. Breaking sharing only |
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* effects the btree of that specific device. Btrees for the other |
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* devices that share the block never change. The btree for the origin |
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* device as it was after the last commit is untouched, ie. we're using |
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* persistent data structures in the functional programming sense. |
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* |
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* v) unplug io to this physical block, including the io that triggered |
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* the breaking of sharing. |
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* |
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* Steps (ii) and (iii) occur in parallel. |
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* |
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* The metadata _doesn't_ need to be committed before the io continues. We |
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* get away with this because the io is always written to a _new_ block. |
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* If there's a crash, then: |
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* |
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* - The origin mapping will point to the old origin block (the shared |
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* one). This will contain the data as it was before the io that triggered |
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* the breaking of sharing came in. |
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* |
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* - The snap mapping still points to the old block. As it would after |
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* the commit. |
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* |
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* The downside of this scheme is the timestamp magic isn't perfect, and |
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* will continue to think that data block in the snapshot device is shared |
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* even after the write to the origin has broken sharing. I suspect data |
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* blocks will typically be shared by many different devices, so we're |
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* breaking sharing n + 1 times, rather than n, where n is the number of |
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* devices that reference this data block. At the moment I think the |
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* benefits far, far outweigh the disadvantages. |
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*/ |
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|
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/*----------------------------------------------------------------*/ |
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|
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/* |
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* Key building. |
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*/ |
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enum lock_space { |
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VIRTUAL, |
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PHYSICAL |
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}; |
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|
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static void build_key(struct dm_thin_device *td, enum lock_space ls, |
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dm_block_t b, dm_block_t e, struct dm_cell_key *key) |
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{ |
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key->virtual = (ls == VIRTUAL); |
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key->dev = dm_thin_dev_id(td); |
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key->block_begin = b; |
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key->block_end = e; |
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} |
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|
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static void build_data_key(struct dm_thin_device *td, dm_block_t b, |
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struct dm_cell_key *key) |
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{ |
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build_key(td, PHYSICAL, b, b + 1llu, key); |
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} |
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|
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static void build_virtual_key(struct dm_thin_device *td, dm_block_t b, |
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struct dm_cell_key *key) |
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{ |
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build_key(td, VIRTUAL, b, b + 1llu, key); |
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} |
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|
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/*----------------------------------------------------------------*/ |
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#define THROTTLE_THRESHOLD (1 * HZ) |
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struct throttle { |
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struct rw_semaphore lock; |
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unsigned long threshold; |
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bool throttle_applied; |
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}; |
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static void throttle_init(struct throttle *t) |
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{ |
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init_rwsem(&t->lock); |
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t->throttle_applied = false; |
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} |
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|
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static void throttle_work_start(struct throttle *t) |
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{ |
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t->threshold = jiffies + THROTTLE_THRESHOLD; |
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} |
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|
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static void throttle_work_update(struct throttle *t) |
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{ |
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if (!t->throttle_applied && jiffies > t->threshold) { |
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down_write(&t->lock); |
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t->throttle_applied = true; |
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} |
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} |
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|
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static void throttle_work_complete(struct throttle *t) |
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{ |
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if (t->throttle_applied) { |
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t->throttle_applied = false; |
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up_write(&t->lock); |
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} |
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} |
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|
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static void throttle_lock(struct throttle *t) |
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{ |
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down_read(&t->lock); |
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} |
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|
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static void throttle_unlock(struct throttle *t) |
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{ |
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up_read(&t->lock); |
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} |
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|
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/*----------------------------------------------------------------*/ |
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|
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/* |
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* A pool device ties together a metadata device and a data device. It |
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* also provides the interface for creating and destroying internal |
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* devices. |
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*/ |
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struct dm_thin_new_mapping; |
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|
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/* |
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* The pool runs in various modes. Ordered in degraded order for comparisons. |
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*/ |
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enum pool_mode { |
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PM_WRITE, /* metadata may be changed */ |
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PM_OUT_OF_DATA_SPACE, /* metadata may be changed, though data may not be allocated */ |
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|
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/* |
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* Like READ_ONLY, except may switch back to WRITE on metadata resize. Reported as READ_ONLY. |
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*/ |
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PM_OUT_OF_METADATA_SPACE, |
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PM_READ_ONLY, /* metadata may not be changed */ |
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|
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PM_FAIL, /* all I/O fails */ |
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}; |
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struct pool_features { |
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enum pool_mode mode; |
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|
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bool zero_new_blocks:1; |
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bool discard_enabled:1; |
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bool discard_passdown:1; |
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bool error_if_no_space:1; |
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}; |
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struct thin_c; |
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typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio); |
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typedef void (*process_cell_fn)(struct thin_c *tc, struct dm_bio_prison_cell *cell); |
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typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m); |
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|
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#define CELL_SORT_ARRAY_SIZE 8192 |
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struct pool { |
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struct list_head list; |
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struct dm_target *ti; /* Only set if a pool target is bound */ |
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struct mapped_device *pool_md; |
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struct block_device *data_dev; |
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struct block_device *md_dev; |
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struct dm_pool_metadata *pmd; |
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dm_block_t low_water_blocks; |
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uint32_t sectors_per_block; |
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int sectors_per_block_shift; |
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struct pool_features pf; |
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bool low_water_triggered:1; /* A dm event has been sent */ |
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bool suspended:1; |
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bool out_of_data_space:1; |
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struct dm_bio_prison *prison; |
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struct dm_kcopyd_client *copier; |
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|
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struct work_struct worker; |
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struct workqueue_struct *wq; |
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struct throttle throttle; |
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struct delayed_work waker; |
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struct delayed_work no_space_timeout; |
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|
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unsigned long last_commit_jiffies; |
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unsigned ref_count; |
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spinlock_t lock; |
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struct bio_list deferred_flush_bios; |
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struct bio_list deferred_flush_completions; |
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struct list_head prepared_mappings; |
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struct list_head prepared_discards; |
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struct list_head prepared_discards_pt2; |
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struct list_head active_thins; |
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struct dm_deferred_set *shared_read_ds; |
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struct dm_deferred_set *all_io_ds; |
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struct dm_thin_new_mapping *next_mapping; |
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process_bio_fn process_bio; |
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process_bio_fn process_discard; |
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process_cell_fn process_cell; |
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process_cell_fn process_discard_cell; |
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process_mapping_fn process_prepared_mapping; |
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process_mapping_fn process_prepared_discard; |
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process_mapping_fn process_prepared_discard_pt2; |
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struct dm_bio_prison_cell **cell_sort_array; |
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mempool_t mapping_pool; |
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|
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struct bio flush_bio; |
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}; |
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static void metadata_operation_failed(struct pool *pool, const char *op, int r); |
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|
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static enum pool_mode get_pool_mode(struct pool *pool) |
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{ |
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return pool->pf.mode; |
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} |
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|
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static void notify_of_pool_mode_change(struct pool *pool) |
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{ |
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const char *descs[] = { |
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"write", |
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"out-of-data-space", |
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"read-only", |
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"read-only", |
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"fail" |
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}; |
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const char *extra_desc = NULL; |
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enum pool_mode mode = get_pool_mode(pool); |
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|
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if (mode == PM_OUT_OF_DATA_SPACE) { |
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if (!pool->pf.error_if_no_space) |
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extra_desc = " (queue IO)"; |
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else |
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extra_desc = " (error IO)"; |
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} |
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dm_table_event(pool->ti->table); |
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DMINFO("%s: switching pool to %s%s mode", |
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dm_device_name(pool->pool_md), |
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descs[(int)mode], extra_desc ? : ""); |
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} |
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/* |
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* Target context for a pool. |
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*/ |
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struct pool_c { |
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struct dm_target *ti; |
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struct pool *pool; |
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struct dm_dev *data_dev; |
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struct dm_dev *metadata_dev; |
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dm_block_t low_water_blocks; |
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struct pool_features requested_pf; /* Features requested during table load */ |
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struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */ |
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}; |
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|
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/* |
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* Target context for a thin. |
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*/ |
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struct thin_c { |
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struct list_head list; |
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struct dm_dev *pool_dev; |
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struct dm_dev *origin_dev; |
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sector_t origin_size; |
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dm_thin_id dev_id; |
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|
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struct pool *pool; |
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struct dm_thin_device *td; |
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struct mapped_device *thin_md; |
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bool requeue_mode:1; |
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spinlock_t lock; |
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struct list_head deferred_cells; |
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struct bio_list deferred_bio_list; |
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struct bio_list retry_on_resume_list; |
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struct rb_root sort_bio_list; /* sorted list of deferred bios */ |
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|
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/* |
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* Ensures the thin is not destroyed until the worker has finished |
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* iterating the active_thins list. |
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*/ |
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refcount_t refcount; |
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struct completion can_destroy; |
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}; |
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|
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/*----------------------------------------------------------------*/ |
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|
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static bool block_size_is_power_of_two(struct pool *pool) |
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{ |
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return pool->sectors_per_block_shift >= 0; |
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} |
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static sector_t block_to_sectors(struct pool *pool, dm_block_t b) |
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{ |
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return block_size_is_power_of_two(pool) ? |
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(b << pool->sectors_per_block_shift) : |
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(b * pool->sectors_per_block); |
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} |
|
|
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/*----------------------------------------------------------------*/ |
|
|
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struct discard_op { |
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struct thin_c *tc; |
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struct blk_plug plug; |
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struct bio *parent_bio; |
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struct bio *bio; |
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}; |
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|
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static void begin_discard(struct discard_op *op, struct thin_c *tc, struct bio *parent) |
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{ |
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BUG_ON(!parent); |
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|
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op->tc = tc; |
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blk_start_plug(&op->plug); |
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op->parent_bio = parent; |
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op->bio = NULL; |
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} |
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|
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static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e) |
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{ |
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struct thin_c *tc = op->tc; |
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sector_t s = block_to_sectors(tc->pool, data_b); |
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sector_t len = block_to_sectors(tc->pool, data_e - data_b); |
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|
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return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, |
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GFP_NOWAIT, 0, &op->bio); |
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} |
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|
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static void end_discard(struct discard_op *op, int r) |
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{ |
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if (op->bio) { |
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/* |
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* Even if one of the calls to issue_discard failed, we |
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* need to wait for the chain to complete. |
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*/ |
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bio_chain(op->bio, op->parent_bio); |
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bio_set_op_attrs(op->bio, REQ_OP_DISCARD, 0); |
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submit_bio(op->bio); |
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} |
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|
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blk_finish_plug(&op->plug); |
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|
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/* |
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* Even if r is set, there could be sub discards in flight that we |
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* need to wait for. |
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*/ |
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if (r && !op->parent_bio->bi_status) |
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op->parent_bio->bi_status = errno_to_blk_status(r); |
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bio_endio(op->parent_bio); |
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} |
|
|
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/*----------------------------------------------------------------*/ |
|
|
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/* |
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* wake_worker() is used when new work is queued and when pool_resume is |
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* ready to continue deferred IO processing. |
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*/ |
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static void wake_worker(struct pool *pool) |
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{ |
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queue_work(pool->wq, &pool->worker); |
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} |
|
|
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/*----------------------------------------------------------------*/ |
|
|
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static int bio_detain(struct pool *pool, struct dm_cell_key *key, struct bio *bio, |
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struct dm_bio_prison_cell **cell_result) |
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{ |
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int r; |
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struct dm_bio_prison_cell *cell_prealloc; |
|
|
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/* |
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* Allocate a cell from the prison's mempool. |
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* This might block but it can't fail. |
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*/ |
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cell_prealloc = dm_bio_prison_alloc_cell(pool->prison, GFP_NOIO); |
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|
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r = dm_bio_detain(pool->prison, key, bio, cell_prealloc, cell_result); |
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if (r) |
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/* |
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* We reused an old cell; we can get rid of |
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* the new one. |
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*/ |
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dm_bio_prison_free_cell(pool->prison, cell_prealloc); |
|
|
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return r; |
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} |
|
|
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static void cell_release(struct pool *pool, |
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struct dm_bio_prison_cell *cell, |
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struct bio_list *bios) |
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{ |
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dm_cell_release(pool->prison, cell, bios); |
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dm_bio_prison_free_cell(pool->prison, cell); |
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} |
|
|
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static void cell_visit_release(struct pool *pool, |
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void (*fn)(void *, struct dm_bio_prison_cell *), |
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void *context, |
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struct dm_bio_prison_cell *cell) |
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{ |
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dm_cell_visit_release(pool->prison, fn, context, cell); |
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dm_bio_prison_free_cell(pool->prison, cell); |
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} |
|
|
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static void cell_release_no_holder(struct pool *pool, |
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struct dm_bio_prison_cell *cell, |
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struct bio_list *bios) |
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{ |
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dm_cell_release_no_holder(pool->prison, cell, bios); |
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dm_bio_prison_free_cell(pool->prison, cell); |
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} |
|
|
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static void cell_error_with_code(struct pool *pool, |
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struct dm_bio_prison_cell *cell, blk_status_t error_code) |
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{ |
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dm_cell_error(pool->prison, cell, error_code); |
|
dm_bio_prison_free_cell(pool->prison, cell); |
|
} |
|
|
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static blk_status_t get_pool_io_error_code(struct pool *pool) |
|
{ |
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return pool->out_of_data_space ? BLK_STS_NOSPC : BLK_STS_IOERR; |
|
} |
|
|
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static void cell_error(struct pool *pool, struct dm_bio_prison_cell *cell) |
|
{ |
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cell_error_with_code(pool, cell, get_pool_io_error_code(pool)); |
|
} |
|
|
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static void cell_success(struct pool *pool, struct dm_bio_prison_cell *cell) |
|
{ |
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cell_error_with_code(pool, cell, 0); |
|
} |
|
|
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static void cell_requeue(struct pool *pool, struct dm_bio_prison_cell *cell) |
|
{ |
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cell_error_with_code(pool, cell, BLK_STS_DM_REQUEUE); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
/* |
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* A global list of pools that uses a struct mapped_device as a key. |
|
*/ |
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static struct dm_thin_pool_table { |
|
struct mutex mutex; |
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struct list_head pools; |
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} dm_thin_pool_table; |
|
|
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static void pool_table_init(void) |
|
{ |
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mutex_init(&dm_thin_pool_table.mutex); |
|
INIT_LIST_HEAD(&dm_thin_pool_table.pools); |
|
} |
|
|
|
static void pool_table_exit(void) |
|
{ |
|
mutex_destroy(&dm_thin_pool_table.mutex); |
|
} |
|
|
|
static void __pool_table_insert(struct pool *pool) |
|
{ |
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
list_add(&pool->list, &dm_thin_pool_table.pools); |
|
} |
|
|
|
static void __pool_table_remove(struct pool *pool) |
|
{ |
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
list_del(&pool->list); |
|
} |
|
|
|
static struct pool *__pool_table_lookup(struct mapped_device *md) |
|
{ |
|
struct pool *pool = NULL, *tmp; |
|
|
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
|
|
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { |
|
if (tmp->pool_md == md) { |
|
pool = tmp; |
|
break; |
|
} |
|
} |
|
|
|
return pool; |
|
} |
|
|
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static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev) |
|
{ |
|
struct pool *pool = NULL, *tmp; |
|
|
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
|
|
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { |
|
if (tmp->md_dev == md_dev) { |
|
pool = tmp; |
|
break; |
|
} |
|
} |
|
|
|
return pool; |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
struct dm_thin_endio_hook { |
|
struct thin_c *tc; |
|
struct dm_deferred_entry *shared_read_entry; |
|
struct dm_deferred_entry *all_io_entry; |
|
struct dm_thin_new_mapping *overwrite_mapping; |
|
struct rb_node rb_node; |
|
struct dm_bio_prison_cell *cell; |
|
}; |
|
|
|
static void __merge_bio_list(struct bio_list *bios, struct bio_list *master) |
|
{ |
|
bio_list_merge(bios, master); |
|
bio_list_init(master); |
|
} |
|
|
|
static void error_bio_list(struct bio_list *bios, blk_status_t error) |
|
{ |
|
struct bio *bio; |
|
|
|
while ((bio = bio_list_pop(bios))) { |
|
bio->bi_status = error; |
|
bio_endio(bio); |
|
} |
|
} |
|
|
|
static void error_thin_bio_list(struct thin_c *tc, struct bio_list *master, |
|
blk_status_t error) |
|
{ |
|
struct bio_list bios; |
|
|
|
bio_list_init(&bios); |
|
|
|
spin_lock_irq(&tc->lock); |
|
__merge_bio_list(&bios, master); |
|
spin_unlock_irq(&tc->lock); |
|
|
|
error_bio_list(&bios, error); |
|
} |
|
|
|
static void requeue_deferred_cells(struct thin_c *tc) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct list_head cells; |
|
struct dm_bio_prison_cell *cell, *tmp; |
|
|
|
INIT_LIST_HEAD(&cells); |
|
|
|
spin_lock_irq(&tc->lock); |
|
list_splice_init(&tc->deferred_cells, &cells); |
|
spin_unlock_irq(&tc->lock); |
|
|
|
list_for_each_entry_safe(cell, tmp, &cells, user_list) |
|
cell_requeue(pool, cell); |
|
} |
|
|
|
static void requeue_io(struct thin_c *tc) |
|
{ |
|
struct bio_list bios; |
|
|
|
bio_list_init(&bios); |
|
|
|
spin_lock_irq(&tc->lock); |
|
__merge_bio_list(&bios, &tc->deferred_bio_list); |
|
__merge_bio_list(&bios, &tc->retry_on_resume_list); |
|
spin_unlock_irq(&tc->lock); |
|
|
|
error_bio_list(&bios, BLK_STS_DM_REQUEUE); |
|
requeue_deferred_cells(tc); |
|
} |
|
|
|
static void error_retry_list_with_code(struct pool *pool, blk_status_t error) |
|
{ |
|
struct thin_c *tc; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(tc, &pool->active_thins, list) |
|
error_thin_bio_list(tc, &tc->retry_on_resume_list, error); |
|
rcu_read_unlock(); |
|
} |
|
|
|
static void error_retry_list(struct pool *pool) |
|
{ |
|
error_retry_list_with_code(pool, get_pool_io_error_code(pool)); |
|
} |
|
|
|
/* |
|
* This section of code contains the logic for processing a thin device's IO. |
|
* Much of the code depends on pool object resources (lists, workqueues, etc) |
|
* but most is exclusively called from the thin target rather than the thin-pool |
|
* target. |
|
*/ |
|
|
|
static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
sector_t block_nr = bio->bi_iter.bi_sector; |
|
|
|
if (block_size_is_power_of_two(pool)) |
|
block_nr >>= pool->sectors_per_block_shift; |
|
else |
|
(void) sector_div(block_nr, pool->sectors_per_block); |
|
|
|
return block_nr; |
|
} |
|
|
|
/* |
|
* Returns the _complete_ blocks that this bio covers. |
|
*/ |
|
static void get_bio_block_range(struct thin_c *tc, struct bio *bio, |
|
dm_block_t *begin, dm_block_t *end) |
|
{ |
|
struct pool *pool = tc->pool; |
|
sector_t b = bio->bi_iter.bi_sector; |
|
sector_t e = b + (bio->bi_iter.bi_size >> SECTOR_SHIFT); |
|
|
|
b += pool->sectors_per_block - 1ull; /* so we round up */ |
|
|
|
if (block_size_is_power_of_two(pool)) { |
|
b >>= pool->sectors_per_block_shift; |
|
e >>= pool->sectors_per_block_shift; |
|
} else { |
|
(void) sector_div(b, pool->sectors_per_block); |
|
(void) sector_div(e, pool->sectors_per_block); |
|
} |
|
|
|
if (e < b) |
|
/* Can happen if the bio is within a single block. */ |
|
e = b; |
|
|
|
*begin = b; |
|
*end = e; |
|
} |
|
|
|
static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block) |
|
{ |
|
struct pool *pool = tc->pool; |
|
sector_t bi_sector = bio->bi_iter.bi_sector; |
|
|
|
bio_set_dev(bio, tc->pool_dev->bdev); |
|
if (block_size_is_power_of_two(pool)) |
|
bio->bi_iter.bi_sector = |
|
(block << pool->sectors_per_block_shift) | |
|
(bi_sector & (pool->sectors_per_block - 1)); |
|
else |
|
bio->bi_iter.bi_sector = (block * pool->sectors_per_block) + |
|
sector_div(bi_sector, pool->sectors_per_block); |
|
} |
|
|
|
static void remap_to_origin(struct thin_c *tc, struct bio *bio) |
|
{ |
|
bio_set_dev(bio, tc->origin_dev->bdev); |
|
} |
|
|
|
static int bio_triggers_commit(struct thin_c *tc, struct bio *bio) |
|
{ |
|
return op_is_flush(bio->bi_opf) && |
|
dm_thin_changed_this_transaction(tc->td); |
|
} |
|
|
|
static void inc_all_io_entry(struct pool *pool, struct bio *bio) |
|
{ |
|
struct dm_thin_endio_hook *h; |
|
|
|
if (bio_op(bio) == REQ_OP_DISCARD) |
|
return; |
|
|
|
h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds); |
|
} |
|
|
|
static void issue(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
if (!bio_triggers_commit(tc, bio)) { |
|
submit_bio_noacct(bio); |
|
return; |
|
} |
|
|
|
/* |
|
* Complete bio with an error if earlier I/O caused changes to |
|
* the metadata that can't be committed e.g, due to I/O errors |
|
* on the metadata device. |
|
*/ |
|
if (dm_thin_aborted_changes(tc->td)) { |
|
bio_io_error(bio); |
|
return; |
|
} |
|
|
|
/* |
|
* Batch together any bios that trigger commits and then issue a |
|
* single commit for them in process_deferred_bios(). |
|
*/ |
|
spin_lock_irq(&pool->lock); |
|
bio_list_add(&pool->deferred_flush_bios, bio); |
|
spin_unlock_irq(&pool->lock); |
|
} |
|
|
|
static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio) |
|
{ |
|
remap_to_origin(tc, bio); |
|
issue(tc, bio); |
|
} |
|
|
|
static void remap_and_issue(struct thin_c *tc, struct bio *bio, |
|
dm_block_t block) |
|
{ |
|
remap(tc, bio, block); |
|
issue(tc, bio); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
/* |
|
* Bio endio functions. |
|
*/ |
|
struct dm_thin_new_mapping { |
|
struct list_head list; |
|
|
|
bool pass_discard:1; |
|
bool maybe_shared:1; |
|
|
|
/* |
|
* Track quiescing, copying and zeroing preparation actions. When this |
|
* counter hits zero the block is prepared and can be inserted into the |
|
* btree. |
|
*/ |
|
atomic_t prepare_actions; |
|
|
|
blk_status_t status; |
|
struct thin_c *tc; |
|
dm_block_t virt_begin, virt_end; |
|
dm_block_t data_block; |
|
struct dm_bio_prison_cell *cell; |
|
|
|
/* |
|
* If the bio covers the whole area of a block then we can avoid |
|
* zeroing or copying. Instead this bio is hooked. The bio will |
|
* still be in the cell, so care has to be taken to avoid issuing |
|
* the bio twice. |
|
*/ |
|
struct bio *bio; |
|
bio_end_io_t *saved_bi_end_io; |
|
}; |
|
|
|
static void __complete_mapping_preparation(struct dm_thin_new_mapping *m) |
|
{ |
|
struct pool *pool = m->tc->pool; |
|
|
|
if (atomic_dec_and_test(&m->prepare_actions)) { |
|
list_add_tail(&m->list, &pool->prepared_mappings); |
|
wake_worker(pool); |
|
} |
|
} |
|
|
|
static void complete_mapping_preparation(struct dm_thin_new_mapping *m) |
|
{ |
|
unsigned long flags; |
|
struct pool *pool = m->tc->pool; |
|
|
|
spin_lock_irqsave(&pool->lock, flags); |
|
__complete_mapping_preparation(m); |
|
spin_unlock_irqrestore(&pool->lock, flags); |
|
} |
|
|
|
static void copy_complete(int read_err, unsigned long write_err, void *context) |
|
{ |
|
struct dm_thin_new_mapping *m = context; |
|
|
|
m->status = read_err || write_err ? BLK_STS_IOERR : 0; |
|
complete_mapping_preparation(m); |
|
} |
|
|
|
static void overwrite_endio(struct bio *bio) |
|
{ |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
struct dm_thin_new_mapping *m = h->overwrite_mapping; |
|
|
|
bio->bi_end_io = m->saved_bi_end_io; |
|
|
|
m->status = bio->bi_status; |
|
complete_mapping_preparation(m); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
/* |
|
* Workqueue. |
|
*/ |
|
|
|
/* |
|
* Prepared mapping jobs. |
|
*/ |
|
|
|
/* |
|
* This sends the bios in the cell, except the original holder, back |
|
* to the deferred_bios list. |
|
*/ |
|
static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
struct pool *pool = tc->pool; |
|
unsigned long flags; |
|
int has_work; |
|
|
|
spin_lock_irqsave(&tc->lock, flags); |
|
cell_release_no_holder(pool, cell, &tc->deferred_bio_list); |
|
has_work = !bio_list_empty(&tc->deferred_bio_list); |
|
spin_unlock_irqrestore(&tc->lock, flags); |
|
|
|
if (has_work) |
|
wake_worker(pool); |
|
} |
|
|
|
static void thin_defer_bio(struct thin_c *tc, struct bio *bio); |
|
|
|
struct remap_info { |
|
struct thin_c *tc; |
|
struct bio_list defer_bios; |
|
struct bio_list issue_bios; |
|
}; |
|
|
|
static void __inc_remap_and_issue_cell(void *context, |
|
struct dm_bio_prison_cell *cell) |
|
{ |
|
struct remap_info *info = context; |
|
struct bio *bio; |
|
|
|
while ((bio = bio_list_pop(&cell->bios))) { |
|
if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) |
|
bio_list_add(&info->defer_bios, bio); |
|
else { |
|
inc_all_io_entry(info->tc->pool, bio); |
|
|
|
/* |
|
* We can't issue the bios with the bio prison lock |
|
* held, so we add them to a list to issue on |
|
* return from this function. |
|
*/ |
|
bio_list_add(&info->issue_bios, bio); |
|
} |
|
} |
|
} |
|
|
|
static void inc_remap_and_issue_cell(struct thin_c *tc, |
|
struct dm_bio_prison_cell *cell, |
|
dm_block_t block) |
|
{ |
|
struct bio *bio; |
|
struct remap_info info; |
|
|
|
info.tc = tc; |
|
bio_list_init(&info.defer_bios); |
|
bio_list_init(&info.issue_bios); |
|
|
|
/* |
|
* We have to be careful to inc any bios we're about to issue |
|
* before the cell is released, and avoid a race with new bios |
|
* being added to the cell. |
|
*/ |
|
cell_visit_release(tc->pool, __inc_remap_and_issue_cell, |
|
&info, cell); |
|
|
|
while ((bio = bio_list_pop(&info.defer_bios))) |
|
thin_defer_bio(tc, bio); |
|
|
|
while ((bio = bio_list_pop(&info.issue_bios))) |
|
remap_and_issue(info.tc, bio, block); |
|
} |
|
|
|
static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m) |
|
{ |
|
cell_error(m->tc->pool, m->cell); |
|
list_del(&m->list); |
|
mempool_free(m, &m->tc->pool->mapping_pool); |
|
} |
|
|
|
static void complete_overwrite_bio(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
/* |
|
* If the bio has the REQ_FUA flag set we must commit the metadata |
|
* before signaling its completion. |
|
*/ |
|
if (!bio_triggers_commit(tc, bio)) { |
|
bio_endio(bio); |
|
return; |
|
} |
|
|
|
/* |
|
* Complete bio with an error if earlier I/O caused changes to the |
|
* metadata that can't be committed, e.g, due to I/O errors on the |
|
* metadata device. |
|
*/ |
|
if (dm_thin_aborted_changes(tc->td)) { |
|
bio_io_error(bio); |
|
return; |
|
} |
|
|
|
/* |
|
* Batch together any bios that trigger commits and then issue a |
|
* single commit for them in process_deferred_bios(). |
|
*/ |
|
spin_lock_irq(&pool->lock); |
|
bio_list_add(&pool->deferred_flush_completions, bio); |
|
spin_unlock_irq(&pool->lock); |
|
} |
|
|
|
static void process_prepared_mapping(struct dm_thin_new_mapping *m) |
|
{ |
|
struct thin_c *tc = m->tc; |
|
struct pool *pool = tc->pool; |
|
struct bio *bio = m->bio; |
|
int r; |
|
|
|
if (m->status) { |
|
cell_error(pool, m->cell); |
|
goto out; |
|
} |
|
|
|
/* |
|
* Commit the prepared block into the mapping btree. |
|
* Any I/O for this block arriving after this point will get |
|
* remapped to it directly. |
|
*/ |
|
r = dm_thin_insert_block(tc->td, m->virt_begin, m->data_block); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_thin_insert_block", r); |
|
cell_error(pool, m->cell); |
|
goto out; |
|
} |
|
|
|
/* |
|
* Release any bios held while the block was being provisioned. |
|
* If we are processing a write bio that completely covers the block, |
|
* we already processed it so can ignore it now when processing |
|
* the bios in the cell. |
|
*/ |
|
if (bio) { |
|
inc_remap_and_issue_cell(tc, m->cell, m->data_block); |
|
complete_overwrite_bio(tc, bio); |
|
} else { |
|
inc_all_io_entry(tc->pool, m->cell->holder); |
|
remap_and_issue(tc, m->cell->holder, m->data_block); |
|
inc_remap_and_issue_cell(tc, m->cell, m->data_block); |
|
} |
|
|
|
out: |
|
list_del(&m->list); |
|
mempool_free(m, &pool->mapping_pool); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static void free_discard_mapping(struct dm_thin_new_mapping *m) |
|
{ |
|
struct thin_c *tc = m->tc; |
|
if (m->cell) |
|
cell_defer_no_holder(tc, m->cell); |
|
mempool_free(m, &tc->pool->mapping_pool); |
|
} |
|
|
|
static void process_prepared_discard_fail(struct dm_thin_new_mapping *m) |
|
{ |
|
bio_io_error(m->bio); |
|
free_discard_mapping(m); |
|
} |
|
|
|
static void process_prepared_discard_success(struct dm_thin_new_mapping *m) |
|
{ |
|
bio_endio(m->bio); |
|
free_discard_mapping(m); |
|
} |
|
|
|
static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping *m) |
|
{ |
|
int r; |
|
struct thin_c *tc = m->tc; |
|
|
|
r = dm_thin_remove_range(tc->td, m->cell->key.block_begin, m->cell->key.block_end); |
|
if (r) { |
|
metadata_operation_failed(tc->pool, "dm_thin_remove_range", r); |
|
bio_io_error(m->bio); |
|
} else |
|
bio_endio(m->bio); |
|
|
|
cell_defer_no_holder(tc, m->cell); |
|
mempool_free(m, &tc->pool->mapping_pool); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m, |
|
struct bio *discard_parent) |
|
{ |
|
/* |
|
* We've already unmapped this range of blocks, but before we |
|
* passdown we have to check that these blocks are now unused. |
|
*/ |
|
int r = 0; |
|
bool shared = true; |
|
struct thin_c *tc = m->tc; |
|
struct pool *pool = tc->pool; |
|
dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin; |
|
struct discard_op op; |
|
|
|
begin_discard(&op, tc, discard_parent); |
|
while (b != end) { |
|
/* find start of unmapped run */ |
|
for (; b < end; b++) { |
|
r = dm_pool_block_is_shared(pool->pmd, b, &shared); |
|
if (r) |
|
goto out; |
|
|
|
if (!shared) |
|
break; |
|
} |
|
|
|
if (b == end) |
|
break; |
|
|
|
/* find end of run */ |
|
for (e = b + 1; e != end; e++) { |
|
r = dm_pool_block_is_shared(pool->pmd, e, &shared); |
|
if (r) |
|
goto out; |
|
|
|
if (shared) |
|
break; |
|
} |
|
|
|
r = issue_discard(&op, b, e); |
|
if (r) |
|
goto out; |
|
|
|
b = e; |
|
} |
|
out: |
|
end_discard(&op, r); |
|
} |
|
|
|
static void queue_passdown_pt2(struct dm_thin_new_mapping *m) |
|
{ |
|
unsigned long flags; |
|
struct pool *pool = m->tc->pool; |
|
|
|
spin_lock_irqsave(&pool->lock, flags); |
|
list_add_tail(&m->list, &pool->prepared_discards_pt2); |
|
spin_unlock_irqrestore(&pool->lock, flags); |
|
wake_worker(pool); |
|
} |
|
|
|
static void passdown_endio(struct bio *bio) |
|
{ |
|
/* |
|
* It doesn't matter if the passdown discard failed, we still want |
|
* to unmap (we ignore err). |
|
*/ |
|
queue_passdown_pt2(bio->bi_private); |
|
bio_put(bio); |
|
} |
|
|
|
static void process_prepared_discard_passdown_pt1(struct dm_thin_new_mapping *m) |
|
{ |
|
int r; |
|
struct thin_c *tc = m->tc; |
|
struct pool *pool = tc->pool; |
|
struct bio *discard_parent; |
|
dm_block_t data_end = m->data_block + (m->virt_end - m->virt_begin); |
|
|
|
/* |
|
* Only this thread allocates blocks, so we can be sure that the |
|
* newly unmapped blocks will not be allocated before the end of |
|
* the function. |
|
*/ |
|
r = dm_thin_remove_range(tc->td, m->virt_begin, m->virt_end); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_thin_remove_range", r); |
|
bio_io_error(m->bio); |
|
cell_defer_no_holder(tc, m->cell); |
|
mempool_free(m, &pool->mapping_pool); |
|
return; |
|
} |
|
|
|
/* |
|
* Increment the unmapped blocks. This prevents a race between the |
|
* passdown io and reallocation of freed blocks. |
|
*/ |
|
r = dm_pool_inc_data_range(pool->pmd, m->data_block, data_end); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_inc_data_range", r); |
|
bio_io_error(m->bio); |
|
cell_defer_no_holder(tc, m->cell); |
|
mempool_free(m, &pool->mapping_pool); |
|
return; |
|
} |
|
|
|
discard_parent = bio_alloc(GFP_NOIO, 1); |
|
if (!discard_parent) { |
|
DMWARN("%s: unable to allocate top level discard bio for passdown. Skipping passdown.", |
|
dm_device_name(tc->pool->pool_md)); |
|
queue_passdown_pt2(m); |
|
|
|
} else { |
|
discard_parent->bi_end_io = passdown_endio; |
|
discard_parent->bi_private = m; |
|
|
|
if (m->maybe_shared) |
|
passdown_double_checking_shared_status(m, discard_parent); |
|
else { |
|
struct discard_op op; |
|
|
|
begin_discard(&op, tc, discard_parent); |
|
r = issue_discard(&op, m->data_block, data_end); |
|
end_discard(&op, r); |
|
} |
|
} |
|
} |
|
|
|
static void process_prepared_discard_passdown_pt2(struct dm_thin_new_mapping *m) |
|
{ |
|
int r; |
|
struct thin_c *tc = m->tc; |
|
struct pool *pool = tc->pool; |
|
|
|
/* |
|
* The passdown has completed, so now we can decrement all those |
|
* unmapped blocks. |
|
*/ |
|
r = dm_pool_dec_data_range(pool->pmd, m->data_block, |
|
m->data_block + (m->virt_end - m->virt_begin)); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_dec_data_range", r); |
|
bio_io_error(m->bio); |
|
} else |
|
bio_endio(m->bio); |
|
|
|
cell_defer_no_holder(tc, m->cell); |
|
mempool_free(m, &pool->mapping_pool); |
|
} |
|
|
|
static void process_prepared(struct pool *pool, struct list_head *head, |
|
process_mapping_fn *fn) |
|
{ |
|
struct list_head maps; |
|
struct dm_thin_new_mapping *m, *tmp; |
|
|
|
INIT_LIST_HEAD(&maps); |
|
spin_lock_irq(&pool->lock); |
|
list_splice_init(head, &maps); |
|
spin_unlock_irq(&pool->lock); |
|
|
|
list_for_each_entry_safe(m, tmp, &maps, list) |
|
(*fn)(m); |
|
} |
|
|
|
/* |
|
* Deferred bio jobs. |
|
*/ |
|
static int io_overlaps_block(struct pool *pool, struct bio *bio) |
|
{ |
|
return bio->bi_iter.bi_size == |
|
(pool->sectors_per_block << SECTOR_SHIFT); |
|
} |
|
|
|
static int io_overwrites_block(struct pool *pool, struct bio *bio) |
|
{ |
|
return (bio_data_dir(bio) == WRITE) && |
|
io_overlaps_block(pool, bio); |
|
} |
|
|
|
static void save_and_set_endio(struct bio *bio, bio_end_io_t **save, |
|
bio_end_io_t *fn) |
|
{ |
|
*save = bio->bi_end_io; |
|
bio->bi_end_io = fn; |
|
} |
|
|
|
static int ensure_next_mapping(struct pool *pool) |
|
{ |
|
if (pool->next_mapping) |
|
return 0; |
|
|
|
pool->next_mapping = mempool_alloc(&pool->mapping_pool, GFP_ATOMIC); |
|
|
|
return pool->next_mapping ? 0 : -ENOMEM; |
|
} |
|
|
|
static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool) |
|
{ |
|
struct dm_thin_new_mapping *m = pool->next_mapping; |
|
|
|
BUG_ON(!pool->next_mapping); |
|
|
|
memset(m, 0, sizeof(struct dm_thin_new_mapping)); |
|
INIT_LIST_HEAD(&m->list); |
|
m->bio = NULL; |
|
|
|
pool->next_mapping = NULL; |
|
|
|
return m; |
|
} |
|
|
|
static void ll_zero(struct thin_c *tc, struct dm_thin_new_mapping *m, |
|
sector_t begin, sector_t end) |
|
{ |
|
struct dm_io_region to; |
|
|
|
to.bdev = tc->pool_dev->bdev; |
|
to.sector = begin; |
|
to.count = end - begin; |
|
|
|
dm_kcopyd_zero(tc->pool->copier, 1, &to, 0, copy_complete, m); |
|
} |
|
|
|
static void remap_and_issue_overwrite(struct thin_c *tc, struct bio *bio, |
|
dm_block_t data_begin, |
|
struct dm_thin_new_mapping *m) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
|
|
h->overwrite_mapping = m; |
|
m->bio = bio; |
|
save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); |
|
inc_all_io_entry(pool, bio); |
|
remap_and_issue(tc, bio, data_begin); |
|
} |
|
|
|
/* |
|
* A partial copy also needs to zero the uncopied region. |
|
*/ |
|
static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, |
|
struct dm_dev *origin, dm_block_t data_origin, |
|
dm_block_t data_dest, |
|
struct dm_bio_prison_cell *cell, struct bio *bio, |
|
sector_t len) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct dm_thin_new_mapping *m = get_next_mapping(pool); |
|
|
|
m->tc = tc; |
|
m->virt_begin = virt_block; |
|
m->virt_end = virt_block + 1u; |
|
m->data_block = data_dest; |
|
m->cell = cell; |
|
|
|
/* |
|
* quiesce action + copy action + an extra reference held for the |
|
* duration of this function (we may need to inc later for a |
|
* partial zero). |
|
*/ |
|
atomic_set(&m->prepare_actions, 3); |
|
|
|
if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list)) |
|
complete_mapping_preparation(m); /* already quiesced */ |
|
|
|
/* |
|
* IO to pool_dev remaps to the pool target's data_dev. |
|
* |
|
* If the whole block of data is being overwritten, we can issue the |
|
* bio immediately. Otherwise we use kcopyd to clone the data first. |
|
*/ |
|
if (io_overwrites_block(pool, bio)) |
|
remap_and_issue_overwrite(tc, bio, data_dest, m); |
|
else { |
|
struct dm_io_region from, to; |
|
|
|
from.bdev = origin->bdev; |
|
from.sector = data_origin * pool->sectors_per_block; |
|
from.count = len; |
|
|
|
to.bdev = tc->pool_dev->bdev; |
|
to.sector = data_dest * pool->sectors_per_block; |
|
to.count = len; |
|
|
|
dm_kcopyd_copy(pool->copier, &from, 1, &to, |
|
0, copy_complete, m); |
|
|
|
/* |
|
* Do we need to zero a tail region? |
|
*/ |
|
if (len < pool->sectors_per_block && pool->pf.zero_new_blocks) { |
|
atomic_inc(&m->prepare_actions); |
|
ll_zero(tc, m, |
|
data_dest * pool->sectors_per_block + len, |
|
(data_dest + 1) * pool->sectors_per_block); |
|
} |
|
} |
|
|
|
complete_mapping_preparation(m); /* drop our ref */ |
|
} |
|
|
|
static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block, |
|
dm_block_t data_origin, dm_block_t data_dest, |
|
struct dm_bio_prison_cell *cell, struct bio *bio) |
|
{ |
|
schedule_copy(tc, virt_block, tc->pool_dev, |
|
data_origin, data_dest, cell, bio, |
|
tc->pool->sectors_per_block); |
|
} |
|
|
|
static void schedule_zero(struct thin_c *tc, dm_block_t virt_block, |
|
dm_block_t data_block, struct dm_bio_prison_cell *cell, |
|
struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct dm_thin_new_mapping *m = get_next_mapping(pool); |
|
|
|
atomic_set(&m->prepare_actions, 1); /* no need to quiesce */ |
|
m->tc = tc; |
|
m->virt_begin = virt_block; |
|
m->virt_end = virt_block + 1u; |
|
m->data_block = data_block; |
|
m->cell = cell; |
|
|
|
/* |
|
* If the whole block of data is being overwritten or we are not |
|
* zeroing pre-existing data, we can issue the bio immediately. |
|
* Otherwise we use kcopyd to zero the data first. |
|
*/ |
|
if (pool->pf.zero_new_blocks) { |
|
if (io_overwrites_block(pool, bio)) |
|
remap_and_issue_overwrite(tc, bio, data_block, m); |
|
else |
|
ll_zero(tc, m, data_block * pool->sectors_per_block, |
|
(data_block + 1) * pool->sectors_per_block); |
|
} else |
|
process_prepared_mapping(m); |
|
} |
|
|
|
static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block, |
|
dm_block_t data_dest, |
|
struct dm_bio_prison_cell *cell, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
sector_t virt_block_begin = virt_block * pool->sectors_per_block; |
|
sector_t virt_block_end = (virt_block + 1) * pool->sectors_per_block; |
|
|
|
if (virt_block_end <= tc->origin_size) |
|
schedule_copy(tc, virt_block, tc->origin_dev, |
|
virt_block, data_dest, cell, bio, |
|
pool->sectors_per_block); |
|
|
|
else if (virt_block_begin < tc->origin_size) |
|
schedule_copy(tc, virt_block, tc->origin_dev, |
|
virt_block, data_dest, cell, bio, |
|
tc->origin_size - virt_block_begin); |
|
|
|
else |
|
schedule_zero(tc, virt_block, data_dest, cell, bio); |
|
} |
|
|
|
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode); |
|
|
|
static void requeue_bios(struct pool *pool); |
|
|
|
static bool is_read_only_pool_mode(enum pool_mode mode) |
|
{ |
|
return (mode == PM_OUT_OF_METADATA_SPACE || mode == PM_READ_ONLY); |
|
} |
|
|
|
static bool is_read_only(struct pool *pool) |
|
{ |
|
return is_read_only_pool_mode(get_pool_mode(pool)); |
|
} |
|
|
|
static void check_for_metadata_space(struct pool *pool) |
|
{ |
|
int r; |
|
const char *ooms_reason = NULL; |
|
dm_block_t nr_free; |
|
|
|
r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free); |
|
if (r) |
|
ooms_reason = "Could not get free metadata blocks"; |
|
else if (!nr_free) |
|
ooms_reason = "No free metadata blocks"; |
|
|
|
if (ooms_reason && !is_read_only(pool)) { |
|
DMERR("%s", ooms_reason); |
|
set_pool_mode(pool, PM_OUT_OF_METADATA_SPACE); |
|
} |
|
} |
|
|
|
static void check_for_data_space(struct pool *pool) |
|
{ |
|
int r; |
|
dm_block_t nr_free; |
|
|
|
if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE) |
|
return; |
|
|
|
r = dm_pool_get_free_block_count(pool->pmd, &nr_free); |
|
if (r) |
|
return; |
|
|
|
if (nr_free) { |
|
set_pool_mode(pool, PM_WRITE); |
|
requeue_bios(pool); |
|
} |
|
} |
|
|
|
/* |
|
* A non-zero return indicates read_only or fail_io mode. |
|
* Many callers don't care about the return value. |
|
*/ |
|
static int commit(struct pool *pool) |
|
{ |
|
int r; |
|
|
|
if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE) |
|
return -EINVAL; |
|
|
|
r = dm_pool_commit_metadata(pool->pmd); |
|
if (r) |
|
metadata_operation_failed(pool, "dm_pool_commit_metadata", r); |
|
else { |
|
check_for_metadata_space(pool); |
|
check_for_data_space(pool); |
|
} |
|
|
|
return r; |
|
} |
|
|
|
static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks) |
|
{ |
|
if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) { |
|
DMWARN("%s: reached low water mark for data device: sending event.", |
|
dm_device_name(pool->pool_md)); |
|
spin_lock_irq(&pool->lock); |
|
pool->low_water_triggered = true; |
|
spin_unlock_irq(&pool->lock); |
|
dm_table_event(pool->ti->table); |
|
} |
|
} |
|
|
|
static int alloc_data_block(struct thin_c *tc, dm_block_t *result) |
|
{ |
|
int r; |
|
dm_block_t free_blocks; |
|
struct pool *pool = tc->pool; |
|
|
|
if (WARN_ON(get_pool_mode(pool) != PM_WRITE)) |
|
return -EINVAL; |
|
|
|
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_get_free_block_count", r); |
|
return r; |
|
} |
|
|
|
check_low_water_mark(pool, free_blocks); |
|
|
|
if (!free_blocks) { |
|
/* |
|
* Try to commit to see if that will free up some |
|
* more space. |
|
*/ |
|
r = commit(pool); |
|
if (r) |
|
return r; |
|
|
|
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_get_free_block_count", r); |
|
return r; |
|
} |
|
|
|
if (!free_blocks) { |
|
set_pool_mode(pool, PM_OUT_OF_DATA_SPACE); |
|
return -ENOSPC; |
|
} |
|
} |
|
|
|
r = dm_pool_alloc_data_block(pool->pmd, result); |
|
if (r) { |
|
if (r == -ENOSPC) |
|
set_pool_mode(pool, PM_OUT_OF_DATA_SPACE); |
|
else |
|
metadata_operation_failed(pool, "dm_pool_alloc_data_block", r); |
|
return r; |
|
} |
|
|
|
r = dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_get_free_metadata_block_count", r); |
|
return r; |
|
} |
|
|
|
if (!free_blocks) { |
|
/* Let's commit before we use up the metadata reserve. */ |
|
r = commit(pool); |
|
if (r) |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* If we have run out of space, queue bios until the device is |
|
* resumed, presumably after having been reloaded with more space. |
|
*/ |
|
static void retry_on_resume(struct bio *bio) |
|
{ |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
struct thin_c *tc = h->tc; |
|
|
|
spin_lock_irq(&tc->lock); |
|
bio_list_add(&tc->retry_on_resume_list, bio); |
|
spin_unlock_irq(&tc->lock); |
|
} |
|
|
|
static blk_status_t should_error_unserviceable_bio(struct pool *pool) |
|
{ |
|
enum pool_mode m = get_pool_mode(pool); |
|
|
|
switch (m) { |
|
case PM_WRITE: |
|
/* Shouldn't get here */ |
|
DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode"); |
|
return BLK_STS_IOERR; |
|
|
|
case PM_OUT_OF_DATA_SPACE: |
|
return pool->pf.error_if_no_space ? BLK_STS_NOSPC : 0; |
|
|
|
case PM_OUT_OF_METADATA_SPACE: |
|
case PM_READ_ONLY: |
|
case PM_FAIL: |
|
return BLK_STS_IOERR; |
|
default: |
|
/* Shouldn't get here */ |
|
DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode"); |
|
return BLK_STS_IOERR; |
|
} |
|
} |
|
|
|
static void handle_unserviceable_bio(struct pool *pool, struct bio *bio) |
|
{ |
|
blk_status_t error = should_error_unserviceable_bio(pool); |
|
|
|
if (error) { |
|
bio->bi_status = error; |
|
bio_endio(bio); |
|
} else |
|
retry_on_resume(bio); |
|
} |
|
|
|
static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell) |
|
{ |
|
struct bio *bio; |
|
struct bio_list bios; |
|
blk_status_t error; |
|
|
|
error = should_error_unserviceable_bio(pool); |
|
if (error) { |
|
cell_error_with_code(pool, cell, error); |
|
return; |
|
} |
|
|
|
bio_list_init(&bios); |
|
cell_release(pool, cell, &bios); |
|
|
|
while ((bio = bio_list_pop(&bios))) |
|
retry_on_resume(bio); |
|
} |
|
|
|
static void process_discard_cell_no_passdown(struct thin_c *tc, |
|
struct dm_bio_prison_cell *virt_cell) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct dm_thin_new_mapping *m = get_next_mapping(pool); |
|
|
|
/* |
|
* We don't need to lock the data blocks, since there's no |
|
* passdown. We only lock data blocks for allocation and breaking sharing. |
|
*/ |
|
m->tc = tc; |
|
m->virt_begin = virt_cell->key.block_begin; |
|
m->virt_end = virt_cell->key.block_end; |
|
m->cell = virt_cell; |
|
m->bio = virt_cell->holder; |
|
|
|
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) |
|
pool->process_prepared_discard(m); |
|
} |
|
|
|
static void break_up_discard_bio(struct thin_c *tc, dm_block_t begin, dm_block_t end, |
|
struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
int r; |
|
bool maybe_shared; |
|
struct dm_cell_key data_key; |
|
struct dm_bio_prison_cell *data_cell; |
|
struct dm_thin_new_mapping *m; |
|
dm_block_t virt_begin, virt_end, data_begin; |
|
|
|
while (begin != end) { |
|
r = ensure_next_mapping(pool); |
|
if (r) |
|
/* we did our best */ |
|
return; |
|
|
|
r = dm_thin_find_mapped_range(tc->td, begin, end, &virt_begin, &virt_end, |
|
&data_begin, &maybe_shared); |
|
if (r) |
|
/* |
|
* Silently fail, letting any mappings we've |
|
* created complete. |
|
*/ |
|
break; |
|
|
|
build_key(tc->td, PHYSICAL, data_begin, data_begin + (virt_end - virt_begin), &data_key); |
|
if (bio_detain(tc->pool, &data_key, NULL, &data_cell)) { |
|
/* contention, we'll give up with this range */ |
|
begin = virt_end; |
|
continue; |
|
} |
|
|
|
/* |
|
* IO may still be going to the destination block. We must |
|
* quiesce before we can do the removal. |
|
*/ |
|
m = get_next_mapping(pool); |
|
m->tc = tc; |
|
m->maybe_shared = maybe_shared; |
|
m->virt_begin = virt_begin; |
|
m->virt_end = virt_end; |
|
m->data_block = data_begin; |
|
m->cell = data_cell; |
|
m->bio = bio; |
|
|
|
/* |
|
* The parent bio must not complete before sub discard bios are |
|
* chained to it (see end_discard's bio_chain)! |
|
* |
|
* This per-mapping bi_remaining increment is paired with |
|
* the implicit decrement that occurs via bio_endio() in |
|
* end_discard(). |
|
*/ |
|
bio_inc_remaining(bio); |
|
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) |
|
pool->process_prepared_discard(m); |
|
|
|
begin = virt_end; |
|
} |
|
} |
|
|
|
static void process_discard_cell_passdown(struct thin_c *tc, struct dm_bio_prison_cell *virt_cell) |
|
{ |
|
struct bio *bio = virt_cell->holder; |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
|
|
/* |
|
* The virt_cell will only get freed once the origin bio completes. |
|
* This means it will remain locked while all the individual |
|
* passdown bios are in flight. |
|
*/ |
|
h->cell = virt_cell; |
|
break_up_discard_bio(tc, virt_cell->key.block_begin, virt_cell->key.block_end, bio); |
|
|
|
/* |
|
* We complete the bio now, knowing that the bi_remaining field |
|
* will prevent completion until the sub range discards have |
|
* completed. |
|
*/ |
|
bio_endio(bio); |
|
} |
|
|
|
static void process_discard_bio(struct thin_c *tc, struct bio *bio) |
|
{ |
|
dm_block_t begin, end; |
|
struct dm_cell_key virt_key; |
|
struct dm_bio_prison_cell *virt_cell; |
|
|
|
get_bio_block_range(tc, bio, &begin, &end); |
|
if (begin == end) { |
|
/* |
|
* The discard covers less than a block. |
|
*/ |
|
bio_endio(bio); |
|
return; |
|
} |
|
|
|
build_key(tc->td, VIRTUAL, begin, end, &virt_key); |
|
if (bio_detain(tc->pool, &virt_key, bio, &virt_cell)) |
|
/* |
|
* Potential starvation issue: We're relying on the |
|
* fs/application being well behaved, and not trying to |
|
* send IO to a region at the same time as discarding it. |
|
* If they do this persistently then it's possible this |
|
* cell will never be granted. |
|
*/ |
|
return; |
|
|
|
tc->pool->process_discard_cell(tc, virt_cell); |
|
} |
|
|
|
static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block, |
|
struct dm_cell_key *key, |
|
struct dm_thin_lookup_result *lookup_result, |
|
struct dm_bio_prison_cell *cell) |
|
{ |
|
int r; |
|
dm_block_t data_block; |
|
struct pool *pool = tc->pool; |
|
|
|
r = alloc_data_block(tc, &data_block); |
|
switch (r) { |
|
case 0: |
|
schedule_internal_copy(tc, block, lookup_result->block, |
|
data_block, cell, bio); |
|
break; |
|
|
|
case -ENOSPC: |
|
retry_bios_on_resume(pool, cell); |
|
break; |
|
|
|
default: |
|
DMERR_LIMIT("%s: alloc_data_block() failed: error = %d", |
|
__func__, r); |
|
cell_error(pool, cell); |
|
break; |
|
} |
|
} |
|
|
|
static void __remap_and_issue_shared_cell(void *context, |
|
struct dm_bio_prison_cell *cell) |
|
{ |
|
struct remap_info *info = context; |
|
struct bio *bio; |
|
|
|
while ((bio = bio_list_pop(&cell->bios))) { |
|
if (bio_data_dir(bio) == WRITE || op_is_flush(bio->bi_opf) || |
|
bio_op(bio) == REQ_OP_DISCARD) |
|
bio_list_add(&info->defer_bios, bio); |
|
else { |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
|
|
h->shared_read_entry = dm_deferred_entry_inc(info->tc->pool->shared_read_ds); |
|
inc_all_io_entry(info->tc->pool, bio); |
|
bio_list_add(&info->issue_bios, bio); |
|
} |
|
} |
|
} |
|
|
|
static void remap_and_issue_shared_cell(struct thin_c *tc, |
|
struct dm_bio_prison_cell *cell, |
|
dm_block_t block) |
|
{ |
|
struct bio *bio; |
|
struct remap_info info; |
|
|
|
info.tc = tc; |
|
bio_list_init(&info.defer_bios); |
|
bio_list_init(&info.issue_bios); |
|
|
|
cell_visit_release(tc->pool, __remap_and_issue_shared_cell, |
|
&info, cell); |
|
|
|
while ((bio = bio_list_pop(&info.defer_bios))) |
|
thin_defer_bio(tc, bio); |
|
|
|
while ((bio = bio_list_pop(&info.issue_bios))) |
|
remap_and_issue(tc, bio, block); |
|
} |
|
|
|
static void process_shared_bio(struct thin_c *tc, struct bio *bio, |
|
dm_block_t block, |
|
struct dm_thin_lookup_result *lookup_result, |
|
struct dm_bio_prison_cell *virt_cell) |
|
{ |
|
struct dm_bio_prison_cell *data_cell; |
|
struct pool *pool = tc->pool; |
|
struct dm_cell_key key; |
|
|
|
/* |
|
* If cell is already occupied, then sharing is already in the process |
|
* of being broken so we have nothing further to do here. |
|
*/ |
|
build_data_key(tc->td, lookup_result->block, &key); |
|
if (bio_detain(pool, &key, bio, &data_cell)) { |
|
cell_defer_no_holder(tc, virt_cell); |
|
return; |
|
} |
|
|
|
if (bio_data_dir(bio) == WRITE && bio->bi_iter.bi_size) { |
|
break_sharing(tc, bio, block, &key, lookup_result, data_cell); |
|
cell_defer_no_holder(tc, virt_cell); |
|
} else { |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
|
|
h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds); |
|
inc_all_io_entry(pool, bio); |
|
remap_and_issue(tc, bio, lookup_result->block); |
|
|
|
remap_and_issue_shared_cell(tc, data_cell, lookup_result->block); |
|
remap_and_issue_shared_cell(tc, virt_cell, lookup_result->block); |
|
} |
|
} |
|
|
|
static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block, |
|
struct dm_bio_prison_cell *cell) |
|
{ |
|
int r; |
|
dm_block_t data_block; |
|
struct pool *pool = tc->pool; |
|
|
|
/* |
|
* Remap empty bios (flushes) immediately, without provisioning. |
|
*/ |
|
if (!bio->bi_iter.bi_size) { |
|
inc_all_io_entry(pool, bio); |
|
cell_defer_no_holder(tc, cell); |
|
|
|
remap_and_issue(tc, bio, 0); |
|
return; |
|
} |
|
|
|
/* |
|
* Fill read bios with zeroes and complete them immediately. |
|
*/ |
|
if (bio_data_dir(bio) == READ) { |
|
zero_fill_bio(bio); |
|
cell_defer_no_holder(tc, cell); |
|
bio_endio(bio); |
|
return; |
|
} |
|
|
|
r = alloc_data_block(tc, &data_block); |
|
switch (r) { |
|
case 0: |
|
if (tc->origin_dev) |
|
schedule_external_copy(tc, block, data_block, cell, bio); |
|
else |
|
schedule_zero(tc, block, data_block, cell, bio); |
|
break; |
|
|
|
case -ENOSPC: |
|
retry_bios_on_resume(pool, cell); |
|
break; |
|
|
|
default: |
|
DMERR_LIMIT("%s: alloc_data_block() failed: error = %d", |
|
__func__, r); |
|
cell_error(pool, cell); |
|
break; |
|
} |
|
} |
|
|
|
static void process_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
int r; |
|
struct pool *pool = tc->pool; |
|
struct bio *bio = cell->holder; |
|
dm_block_t block = get_bio_block(tc, bio); |
|
struct dm_thin_lookup_result lookup_result; |
|
|
|
if (tc->requeue_mode) { |
|
cell_requeue(pool, cell); |
|
return; |
|
} |
|
|
|
r = dm_thin_find_block(tc->td, block, 1, &lookup_result); |
|
switch (r) { |
|
case 0: |
|
if (lookup_result.shared) |
|
process_shared_bio(tc, bio, block, &lookup_result, cell); |
|
else { |
|
inc_all_io_entry(pool, bio); |
|
remap_and_issue(tc, bio, lookup_result.block); |
|
inc_remap_and_issue_cell(tc, cell, lookup_result.block); |
|
} |
|
break; |
|
|
|
case -ENODATA: |
|
if (bio_data_dir(bio) == READ && tc->origin_dev) { |
|
inc_all_io_entry(pool, bio); |
|
cell_defer_no_holder(tc, cell); |
|
|
|
if (bio_end_sector(bio) <= tc->origin_size) |
|
remap_to_origin_and_issue(tc, bio); |
|
|
|
else if (bio->bi_iter.bi_sector < tc->origin_size) { |
|
zero_fill_bio(bio); |
|
bio->bi_iter.bi_size = (tc->origin_size - bio->bi_iter.bi_sector) << SECTOR_SHIFT; |
|
remap_to_origin_and_issue(tc, bio); |
|
|
|
} else { |
|
zero_fill_bio(bio); |
|
bio_endio(bio); |
|
} |
|
} else |
|
provision_block(tc, bio, block, cell); |
|
break; |
|
|
|
default: |
|
DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d", |
|
__func__, r); |
|
cell_defer_no_holder(tc, cell); |
|
bio_io_error(bio); |
|
break; |
|
} |
|
} |
|
|
|
static void process_bio(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
dm_block_t block = get_bio_block(tc, bio); |
|
struct dm_bio_prison_cell *cell; |
|
struct dm_cell_key key; |
|
|
|
/* |
|
* If cell is already occupied, then the block is already |
|
* being provisioned so we have nothing further to do here. |
|
*/ |
|
build_virtual_key(tc->td, block, &key); |
|
if (bio_detain(pool, &key, bio, &cell)) |
|
return; |
|
|
|
process_cell(tc, cell); |
|
} |
|
|
|
static void __process_bio_read_only(struct thin_c *tc, struct bio *bio, |
|
struct dm_bio_prison_cell *cell) |
|
{ |
|
int r; |
|
int rw = bio_data_dir(bio); |
|
dm_block_t block = get_bio_block(tc, bio); |
|
struct dm_thin_lookup_result lookup_result; |
|
|
|
r = dm_thin_find_block(tc->td, block, 1, &lookup_result); |
|
switch (r) { |
|
case 0: |
|
if (lookup_result.shared && (rw == WRITE) && bio->bi_iter.bi_size) { |
|
handle_unserviceable_bio(tc->pool, bio); |
|
if (cell) |
|
cell_defer_no_holder(tc, cell); |
|
} else { |
|
inc_all_io_entry(tc->pool, bio); |
|
remap_and_issue(tc, bio, lookup_result.block); |
|
if (cell) |
|
inc_remap_and_issue_cell(tc, cell, lookup_result.block); |
|
} |
|
break; |
|
|
|
case -ENODATA: |
|
if (cell) |
|
cell_defer_no_holder(tc, cell); |
|
if (rw != READ) { |
|
handle_unserviceable_bio(tc->pool, bio); |
|
break; |
|
} |
|
|
|
if (tc->origin_dev) { |
|
inc_all_io_entry(tc->pool, bio); |
|
remap_to_origin_and_issue(tc, bio); |
|
break; |
|
} |
|
|
|
zero_fill_bio(bio); |
|
bio_endio(bio); |
|
break; |
|
|
|
default: |
|
DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d", |
|
__func__, r); |
|
if (cell) |
|
cell_defer_no_holder(tc, cell); |
|
bio_io_error(bio); |
|
break; |
|
} |
|
} |
|
|
|
static void process_bio_read_only(struct thin_c *tc, struct bio *bio) |
|
{ |
|
__process_bio_read_only(tc, bio, NULL); |
|
} |
|
|
|
static void process_cell_read_only(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
__process_bio_read_only(tc, cell->holder, cell); |
|
} |
|
|
|
static void process_bio_success(struct thin_c *tc, struct bio *bio) |
|
{ |
|
bio_endio(bio); |
|
} |
|
|
|
static void process_bio_fail(struct thin_c *tc, struct bio *bio) |
|
{ |
|
bio_io_error(bio); |
|
} |
|
|
|
static void process_cell_success(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
cell_success(tc->pool, cell); |
|
} |
|
|
|
static void process_cell_fail(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
cell_error(tc->pool, cell); |
|
} |
|
|
|
/* |
|
* FIXME: should we also commit due to size of transaction, measured in |
|
* metadata blocks? |
|
*/ |
|
static int need_commit_due_to_time(struct pool *pool) |
|
{ |
|
return !time_in_range(jiffies, pool->last_commit_jiffies, |
|
pool->last_commit_jiffies + COMMIT_PERIOD); |
|
} |
|
|
|
#define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node) |
|
#define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook)) |
|
|
|
static void __thin_bio_rb_add(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct rb_node **rbp, *parent; |
|
struct dm_thin_endio_hook *pbd; |
|
sector_t bi_sector = bio->bi_iter.bi_sector; |
|
|
|
rbp = &tc->sort_bio_list.rb_node; |
|
parent = NULL; |
|
while (*rbp) { |
|
parent = *rbp; |
|
pbd = thin_pbd(parent); |
|
|
|
if (bi_sector < thin_bio(pbd)->bi_iter.bi_sector) |
|
rbp = &(*rbp)->rb_left; |
|
else |
|
rbp = &(*rbp)->rb_right; |
|
} |
|
|
|
pbd = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
rb_link_node(&pbd->rb_node, parent, rbp); |
|
rb_insert_color(&pbd->rb_node, &tc->sort_bio_list); |
|
} |
|
|
|
static void __extract_sorted_bios(struct thin_c *tc) |
|
{ |
|
struct rb_node *node; |
|
struct dm_thin_endio_hook *pbd; |
|
struct bio *bio; |
|
|
|
for (node = rb_first(&tc->sort_bio_list); node; node = rb_next(node)) { |
|
pbd = thin_pbd(node); |
|
bio = thin_bio(pbd); |
|
|
|
bio_list_add(&tc->deferred_bio_list, bio); |
|
rb_erase(&pbd->rb_node, &tc->sort_bio_list); |
|
} |
|
|
|
WARN_ON(!RB_EMPTY_ROOT(&tc->sort_bio_list)); |
|
} |
|
|
|
static void __sort_thin_deferred_bios(struct thin_c *tc) |
|
{ |
|
struct bio *bio; |
|
struct bio_list bios; |
|
|
|
bio_list_init(&bios); |
|
bio_list_merge(&bios, &tc->deferred_bio_list); |
|
bio_list_init(&tc->deferred_bio_list); |
|
|
|
/* Sort deferred_bio_list using rb-tree */ |
|
while ((bio = bio_list_pop(&bios))) |
|
__thin_bio_rb_add(tc, bio); |
|
|
|
/* |
|
* Transfer the sorted bios in sort_bio_list back to |
|
* deferred_bio_list to allow lockless submission of |
|
* all bios. |
|
*/ |
|
__extract_sorted_bios(tc); |
|
} |
|
|
|
static void process_thin_deferred_bios(struct thin_c *tc) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct bio *bio; |
|
struct bio_list bios; |
|
struct blk_plug plug; |
|
unsigned count = 0; |
|
|
|
if (tc->requeue_mode) { |
|
error_thin_bio_list(tc, &tc->deferred_bio_list, |
|
BLK_STS_DM_REQUEUE); |
|
return; |
|
} |
|
|
|
bio_list_init(&bios); |
|
|
|
spin_lock_irq(&tc->lock); |
|
|
|
if (bio_list_empty(&tc->deferred_bio_list)) { |
|
spin_unlock_irq(&tc->lock); |
|
return; |
|
} |
|
|
|
__sort_thin_deferred_bios(tc); |
|
|
|
bio_list_merge(&bios, &tc->deferred_bio_list); |
|
bio_list_init(&tc->deferred_bio_list); |
|
|
|
spin_unlock_irq(&tc->lock); |
|
|
|
blk_start_plug(&plug); |
|
while ((bio = bio_list_pop(&bios))) { |
|
/* |
|
* If we've got no free new_mapping structs, and processing |
|
* this bio might require one, we pause until there are some |
|
* prepared mappings to process. |
|
*/ |
|
if (ensure_next_mapping(pool)) { |
|
spin_lock_irq(&tc->lock); |
|
bio_list_add(&tc->deferred_bio_list, bio); |
|
bio_list_merge(&tc->deferred_bio_list, &bios); |
|
spin_unlock_irq(&tc->lock); |
|
break; |
|
} |
|
|
|
if (bio_op(bio) == REQ_OP_DISCARD) |
|
pool->process_discard(tc, bio); |
|
else |
|
pool->process_bio(tc, bio); |
|
|
|
if ((count++ & 127) == 0) { |
|
throttle_work_update(&pool->throttle); |
|
dm_pool_issue_prefetches(pool->pmd); |
|
} |
|
} |
|
blk_finish_plug(&plug); |
|
} |
|
|
|
static int cmp_cells(const void *lhs, const void *rhs) |
|
{ |
|
struct dm_bio_prison_cell *lhs_cell = *((struct dm_bio_prison_cell **) lhs); |
|
struct dm_bio_prison_cell *rhs_cell = *((struct dm_bio_prison_cell **) rhs); |
|
|
|
BUG_ON(!lhs_cell->holder); |
|
BUG_ON(!rhs_cell->holder); |
|
|
|
if (lhs_cell->holder->bi_iter.bi_sector < rhs_cell->holder->bi_iter.bi_sector) |
|
return -1; |
|
|
|
if (lhs_cell->holder->bi_iter.bi_sector > rhs_cell->holder->bi_iter.bi_sector) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
static unsigned sort_cells(struct pool *pool, struct list_head *cells) |
|
{ |
|
unsigned count = 0; |
|
struct dm_bio_prison_cell *cell, *tmp; |
|
|
|
list_for_each_entry_safe(cell, tmp, cells, user_list) { |
|
if (count >= CELL_SORT_ARRAY_SIZE) |
|
break; |
|
|
|
pool->cell_sort_array[count++] = cell; |
|
list_del(&cell->user_list); |
|
} |
|
|
|
sort(pool->cell_sort_array, count, sizeof(cell), cmp_cells, NULL); |
|
|
|
return count; |
|
} |
|
|
|
static void process_thin_deferred_cells(struct thin_c *tc) |
|
{ |
|
struct pool *pool = tc->pool; |
|
struct list_head cells; |
|
struct dm_bio_prison_cell *cell; |
|
unsigned i, j, count; |
|
|
|
INIT_LIST_HEAD(&cells); |
|
|
|
spin_lock_irq(&tc->lock); |
|
list_splice_init(&tc->deferred_cells, &cells); |
|
spin_unlock_irq(&tc->lock); |
|
|
|
if (list_empty(&cells)) |
|
return; |
|
|
|
do { |
|
count = sort_cells(tc->pool, &cells); |
|
|
|
for (i = 0; i < count; i++) { |
|
cell = pool->cell_sort_array[i]; |
|
BUG_ON(!cell->holder); |
|
|
|
/* |
|
* If we've got no free new_mapping structs, and processing |
|
* this bio might require one, we pause until there are some |
|
* prepared mappings to process. |
|
*/ |
|
if (ensure_next_mapping(pool)) { |
|
for (j = i; j < count; j++) |
|
list_add(&pool->cell_sort_array[j]->user_list, &cells); |
|
|
|
spin_lock_irq(&tc->lock); |
|
list_splice(&cells, &tc->deferred_cells); |
|
spin_unlock_irq(&tc->lock); |
|
return; |
|
} |
|
|
|
if (bio_op(cell->holder) == REQ_OP_DISCARD) |
|
pool->process_discard_cell(tc, cell); |
|
else |
|
pool->process_cell(tc, cell); |
|
} |
|
} while (!list_empty(&cells)); |
|
} |
|
|
|
static void thin_get(struct thin_c *tc); |
|
static void thin_put(struct thin_c *tc); |
|
|
|
/* |
|
* We can't hold rcu_read_lock() around code that can block. So we |
|
* find a thin with the rcu lock held; bump a refcount; then drop |
|
* the lock. |
|
*/ |
|
static struct thin_c *get_first_thin(struct pool *pool) |
|
{ |
|
struct thin_c *tc = NULL; |
|
|
|
rcu_read_lock(); |
|
if (!list_empty(&pool->active_thins)) { |
|
tc = list_entry_rcu(pool->active_thins.next, struct thin_c, list); |
|
thin_get(tc); |
|
} |
|
rcu_read_unlock(); |
|
|
|
return tc; |
|
} |
|
|
|
static struct thin_c *get_next_thin(struct pool *pool, struct thin_c *tc) |
|
{ |
|
struct thin_c *old_tc = tc; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_continue_rcu(tc, &pool->active_thins, list) { |
|
thin_get(tc); |
|
thin_put(old_tc); |
|
rcu_read_unlock(); |
|
return tc; |
|
} |
|
thin_put(old_tc); |
|
rcu_read_unlock(); |
|
|
|
return NULL; |
|
} |
|
|
|
static void process_deferred_bios(struct pool *pool) |
|
{ |
|
struct bio *bio; |
|
struct bio_list bios, bio_completions; |
|
struct thin_c *tc; |
|
|
|
tc = get_first_thin(pool); |
|
while (tc) { |
|
process_thin_deferred_cells(tc); |
|
process_thin_deferred_bios(tc); |
|
tc = get_next_thin(pool, tc); |
|
} |
|
|
|
/* |
|
* If there are any deferred flush bios, we must commit the metadata |
|
* before issuing them or signaling their completion. |
|
*/ |
|
bio_list_init(&bios); |
|
bio_list_init(&bio_completions); |
|
|
|
spin_lock_irq(&pool->lock); |
|
bio_list_merge(&bios, &pool->deferred_flush_bios); |
|
bio_list_init(&pool->deferred_flush_bios); |
|
|
|
bio_list_merge(&bio_completions, &pool->deferred_flush_completions); |
|
bio_list_init(&pool->deferred_flush_completions); |
|
spin_unlock_irq(&pool->lock); |
|
|
|
if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) && |
|
!(dm_pool_changed_this_transaction(pool->pmd) && need_commit_due_to_time(pool))) |
|
return; |
|
|
|
if (commit(pool)) { |
|
bio_list_merge(&bios, &bio_completions); |
|
|
|
while ((bio = bio_list_pop(&bios))) |
|
bio_io_error(bio); |
|
return; |
|
} |
|
pool->last_commit_jiffies = jiffies; |
|
|
|
while ((bio = bio_list_pop(&bio_completions))) |
|
bio_endio(bio); |
|
|
|
while ((bio = bio_list_pop(&bios))) { |
|
/* |
|
* The data device was flushed as part of metadata commit, |
|
* so complete redundant flushes immediately. |
|
*/ |
|
if (bio->bi_opf & REQ_PREFLUSH) |
|
bio_endio(bio); |
|
else |
|
submit_bio_noacct(bio); |
|
} |
|
} |
|
|
|
static void do_worker(struct work_struct *ws) |
|
{ |
|
struct pool *pool = container_of(ws, struct pool, worker); |
|
|
|
throttle_work_start(&pool->throttle); |
|
dm_pool_issue_prefetches(pool->pmd); |
|
throttle_work_update(&pool->throttle); |
|
process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping); |
|
throttle_work_update(&pool->throttle); |
|
process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard); |
|
throttle_work_update(&pool->throttle); |
|
process_prepared(pool, &pool->prepared_discards_pt2, &pool->process_prepared_discard_pt2); |
|
throttle_work_update(&pool->throttle); |
|
process_deferred_bios(pool); |
|
throttle_work_complete(&pool->throttle); |
|
} |
|
|
|
/* |
|
* We want to commit periodically so that not too much |
|
* unwritten data builds up. |
|
*/ |
|
static void do_waker(struct work_struct *ws) |
|
{ |
|
struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker); |
|
wake_worker(pool); |
|
queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD); |
|
} |
|
|
|
/* |
|
* We're holding onto IO to allow userland time to react. After the |
|
* timeout either the pool will have been resized (and thus back in |
|
* PM_WRITE mode), or we degrade to PM_OUT_OF_DATA_SPACE w/ error_if_no_space. |
|
*/ |
|
static void do_no_space_timeout(struct work_struct *ws) |
|
{ |
|
struct pool *pool = container_of(to_delayed_work(ws), struct pool, |
|
no_space_timeout); |
|
|
|
if (get_pool_mode(pool) == PM_OUT_OF_DATA_SPACE && !pool->pf.error_if_no_space) { |
|
pool->pf.error_if_no_space = true; |
|
notify_of_pool_mode_change(pool); |
|
error_retry_list_with_code(pool, BLK_STS_NOSPC); |
|
} |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
struct pool_work { |
|
struct work_struct worker; |
|
struct completion complete; |
|
}; |
|
|
|
static struct pool_work *to_pool_work(struct work_struct *ws) |
|
{ |
|
return container_of(ws, struct pool_work, worker); |
|
} |
|
|
|
static void pool_work_complete(struct pool_work *pw) |
|
{ |
|
complete(&pw->complete); |
|
} |
|
|
|
static void pool_work_wait(struct pool_work *pw, struct pool *pool, |
|
void (*fn)(struct work_struct *)) |
|
{ |
|
INIT_WORK_ONSTACK(&pw->worker, fn); |
|
init_completion(&pw->complete); |
|
queue_work(pool->wq, &pw->worker); |
|
wait_for_completion(&pw->complete); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
struct noflush_work { |
|
struct pool_work pw; |
|
struct thin_c *tc; |
|
}; |
|
|
|
static struct noflush_work *to_noflush(struct work_struct *ws) |
|
{ |
|
return container_of(to_pool_work(ws), struct noflush_work, pw); |
|
} |
|
|
|
static void do_noflush_start(struct work_struct *ws) |
|
{ |
|
struct noflush_work *w = to_noflush(ws); |
|
w->tc->requeue_mode = true; |
|
requeue_io(w->tc); |
|
pool_work_complete(&w->pw); |
|
} |
|
|
|
static void do_noflush_stop(struct work_struct *ws) |
|
{ |
|
struct noflush_work *w = to_noflush(ws); |
|
w->tc->requeue_mode = false; |
|
pool_work_complete(&w->pw); |
|
} |
|
|
|
static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *)) |
|
{ |
|
struct noflush_work w; |
|
|
|
w.tc = tc; |
|
pool_work_wait(&w.pw, tc->pool, fn); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static bool passdown_enabled(struct pool_c *pt) |
|
{ |
|
return pt->adjusted_pf.discard_passdown; |
|
} |
|
|
|
static void set_discard_callbacks(struct pool *pool) |
|
{ |
|
struct pool_c *pt = pool->ti->private; |
|
|
|
if (passdown_enabled(pt)) { |
|
pool->process_discard_cell = process_discard_cell_passdown; |
|
pool->process_prepared_discard = process_prepared_discard_passdown_pt1; |
|
pool->process_prepared_discard_pt2 = process_prepared_discard_passdown_pt2; |
|
} else { |
|
pool->process_discard_cell = process_discard_cell_no_passdown; |
|
pool->process_prepared_discard = process_prepared_discard_no_passdown; |
|
} |
|
} |
|
|
|
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode) |
|
{ |
|
struct pool_c *pt = pool->ti->private; |
|
bool needs_check = dm_pool_metadata_needs_check(pool->pmd); |
|
enum pool_mode old_mode = get_pool_mode(pool); |
|
unsigned long no_space_timeout = READ_ONCE(no_space_timeout_secs) * HZ; |
|
|
|
/* |
|
* Never allow the pool to transition to PM_WRITE mode if user |
|
* intervention is required to verify metadata and data consistency. |
|
*/ |
|
if (new_mode == PM_WRITE && needs_check) { |
|
DMERR("%s: unable to switch pool to write mode until repaired.", |
|
dm_device_name(pool->pool_md)); |
|
if (old_mode != new_mode) |
|
new_mode = old_mode; |
|
else |
|
new_mode = PM_READ_ONLY; |
|
} |
|
/* |
|
* If we were in PM_FAIL mode, rollback of metadata failed. We're |
|
* not going to recover without a thin_repair. So we never let the |
|
* pool move out of the old mode. |
|
*/ |
|
if (old_mode == PM_FAIL) |
|
new_mode = old_mode; |
|
|
|
switch (new_mode) { |
|
case PM_FAIL: |
|
dm_pool_metadata_read_only(pool->pmd); |
|
pool->process_bio = process_bio_fail; |
|
pool->process_discard = process_bio_fail; |
|
pool->process_cell = process_cell_fail; |
|
pool->process_discard_cell = process_cell_fail; |
|
pool->process_prepared_mapping = process_prepared_mapping_fail; |
|
pool->process_prepared_discard = process_prepared_discard_fail; |
|
|
|
error_retry_list(pool); |
|
break; |
|
|
|
case PM_OUT_OF_METADATA_SPACE: |
|
case PM_READ_ONLY: |
|
dm_pool_metadata_read_only(pool->pmd); |
|
pool->process_bio = process_bio_read_only; |
|
pool->process_discard = process_bio_success; |
|
pool->process_cell = process_cell_read_only; |
|
pool->process_discard_cell = process_cell_success; |
|
pool->process_prepared_mapping = process_prepared_mapping_fail; |
|
pool->process_prepared_discard = process_prepared_discard_success; |
|
|
|
error_retry_list(pool); |
|
break; |
|
|
|
case PM_OUT_OF_DATA_SPACE: |
|
/* |
|
* Ideally we'd never hit this state; the low water mark |
|
* would trigger userland to extend the pool before we |
|
* completely run out of data space. However, many small |
|
* IOs to unprovisioned space can consume data space at an |
|
* alarming rate. Adjust your low water mark if you're |
|
* frequently seeing this mode. |
|
*/ |
|
pool->out_of_data_space = true; |
|
pool->process_bio = process_bio_read_only; |
|
pool->process_discard = process_discard_bio; |
|
pool->process_cell = process_cell_read_only; |
|
pool->process_prepared_mapping = process_prepared_mapping; |
|
set_discard_callbacks(pool); |
|
|
|
if (!pool->pf.error_if_no_space && no_space_timeout) |
|
queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout); |
|
break; |
|
|
|
case PM_WRITE: |
|
if (old_mode == PM_OUT_OF_DATA_SPACE) |
|
cancel_delayed_work_sync(&pool->no_space_timeout); |
|
pool->out_of_data_space = false; |
|
pool->pf.error_if_no_space = pt->requested_pf.error_if_no_space; |
|
dm_pool_metadata_read_write(pool->pmd); |
|
pool->process_bio = process_bio; |
|
pool->process_discard = process_discard_bio; |
|
pool->process_cell = process_cell; |
|
pool->process_prepared_mapping = process_prepared_mapping; |
|
set_discard_callbacks(pool); |
|
break; |
|
} |
|
|
|
pool->pf.mode = new_mode; |
|
/* |
|
* The pool mode may have changed, sync it so bind_control_target() |
|
* doesn't cause an unexpected mode transition on resume. |
|
*/ |
|
pt->adjusted_pf.mode = new_mode; |
|
|
|
if (old_mode != new_mode) |
|
notify_of_pool_mode_change(pool); |
|
} |
|
|
|
static void abort_transaction(struct pool *pool) |
|
{ |
|
const char *dev_name = dm_device_name(pool->pool_md); |
|
|
|
DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
|
if (dm_pool_abort_metadata(pool->pmd)) { |
|
DMERR("%s: failed to abort metadata transaction", dev_name); |
|
set_pool_mode(pool, PM_FAIL); |
|
} |
|
|
|
if (dm_pool_metadata_set_needs_check(pool->pmd)) { |
|
DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
|
set_pool_mode(pool, PM_FAIL); |
|
} |
|
} |
|
|
|
static void metadata_operation_failed(struct pool *pool, const char *op, int r) |
|
{ |
|
DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
|
dm_device_name(pool->pool_md), op, r); |
|
|
|
abort_transaction(pool); |
|
set_pool_mode(pool, PM_READ_ONLY); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
/* |
|
* Mapping functions. |
|
*/ |
|
|
|
/* |
|
* Called only while mapping a thin bio to hand it over to the workqueue. |
|
*/ |
|
static void thin_defer_bio(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
spin_lock_irq(&tc->lock); |
|
bio_list_add(&tc->deferred_bio_list, bio); |
|
spin_unlock_irq(&tc->lock); |
|
|
|
wake_worker(pool); |
|
} |
|
|
|
static void thin_defer_bio_with_throttle(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
throttle_lock(&pool->throttle); |
|
thin_defer_bio(tc, bio); |
|
throttle_unlock(&pool->throttle); |
|
} |
|
|
|
static void thin_defer_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
|
{ |
|
struct pool *pool = tc->pool; |
|
|
|
throttle_lock(&pool->throttle); |
|
spin_lock_irq(&tc->lock); |
|
list_add_tail(&cell->user_list, &tc->deferred_cells); |
|
spin_unlock_irq(&tc->lock); |
|
throttle_unlock(&pool->throttle); |
|
|
|
wake_worker(pool); |
|
} |
|
|
|
static void thin_hook_bio(struct thin_c *tc, struct bio *bio) |
|
{ |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
|
|
h->tc = tc; |
|
h->shared_read_entry = NULL; |
|
h->all_io_entry = NULL; |
|
h->overwrite_mapping = NULL; |
|
h->cell = NULL; |
|
} |
|
|
|
/* |
|
* Non-blocking function called from the thin target's map function. |
|
*/ |
|
static int thin_bio_map(struct dm_target *ti, struct bio *bio) |
|
{ |
|
int r; |
|
struct thin_c *tc = ti->private; |
|
dm_block_t block = get_bio_block(tc, bio); |
|
struct dm_thin_device *td = tc->td; |
|
struct dm_thin_lookup_result result; |
|
struct dm_bio_prison_cell *virt_cell, *data_cell; |
|
struct dm_cell_key key; |
|
|
|
thin_hook_bio(tc, bio); |
|
|
|
if (tc->requeue_mode) { |
|
bio->bi_status = BLK_STS_DM_REQUEUE; |
|
bio_endio(bio); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
if (get_pool_mode(tc->pool) == PM_FAIL) { |
|
bio_io_error(bio); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) { |
|
thin_defer_bio_with_throttle(tc, bio); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
/* |
|
* We must hold the virtual cell before doing the lookup, otherwise |
|
* there's a race with discard. |
|
*/ |
|
build_virtual_key(tc->td, block, &key); |
|
if (bio_detain(tc->pool, &key, bio, &virt_cell)) |
|
return DM_MAPIO_SUBMITTED; |
|
|
|
r = dm_thin_find_block(td, block, 0, &result); |
|
|
|
/* |
|
* Note that we defer readahead too. |
|
*/ |
|
switch (r) { |
|
case 0: |
|
if (unlikely(result.shared)) { |
|
/* |
|
* We have a race condition here between the |
|
* result.shared value returned by the lookup and |
|
* snapshot creation, which may cause new |
|
* sharing. |
|
* |
|
* To avoid this always quiesce the origin before |
|
* taking the snap. You want to do this anyway to |
|
* ensure a consistent application view |
|
* (i.e. lockfs). |
|
* |
|
* More distant ancestors are irrelevant. The |
|
* shared flag will be set in their case. |
|
*/ |
|
thin_defer_cell(tc, virt_cell); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
build_data_key(tc->td, result.block, &key); |
|
if (bio_detain(tc->pool, &key, bio, &data_cell)) { |
|
cell_defer_no_holder(tc, virt_cell); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
inc_all_io_entry(tc->pool, bio); |
|
cell_defer_no_holder(tc, data_cell); |
|
cell_defer_no_holder(tc, virt_cell); |
|
|
|
remap(tc, bio, result.block); |
|
return DM_MAPIO_REMAPPED; |
|
|
|
case -ENODATA: |
|
case -EWOULDBLOCK: |
|
thin_defer_cell(tc, virt_cell); |
|
return DM_MAPIO_SUBMITTED; |
|
|
|
default: |
|
/* |
|
* Must always call bio_io_error on failure. |
|
* dm_thin_find_block can fail with -EINVAL if the |
|
* pool is switched to fail-io mode. |
|
*/ |
|
bio_io_error(bio); |
|
cell_defer_no_holder(tc, virt_cell); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
} |
|
|
|
static void requeue_bios(struct pool *pool) |
|
{ |
|
struct thin_c *tc; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(tc, &pool->active_thins, list) { |
|
spin_lock_irq(&tc->lock); |
|
bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list); |
|
bio_list_init(&tc->retry_on_resume_list); |
|
spin_unlock_irq(&tc->lock); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Binding of control targets to a pool object |
|
*--------------------------------------------------------------*/ |
|
static bool data_dev_supports_discard(struct pool_c *pt) |
|
{ |
|
struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); |
|
|
|
return blk_queue_discard(q); |
|
} |
|
|
|
static bool is_factor(sector_t block_size, uint32_t n) |
|
{ |
|
return !sector_div(block_size, n); |
|
} |
|
|
|
/* |
|
* If discard_passdown was enabled verify that the data device |
|
* supports discards. Disable discard_passdown if not. |
|
*/ |
|
static void disable_passdown_if_not_supported(struct pool_c *pt) |
|
{ |
|
struct pool *pool = pt->pool; |
|
struct block_device *data_bdev = pt->data_dev->bdev; |
|
struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits; |
|
const char *reason = NULL; |
|
char buf[BDEVNAME_SIZE]; |
|
|
|
if (!pt->adjusted_pf.discard_passdown) |
|
return; |
|
|
|
if (!data_dev_supports_discard(pt)) |
|
reason = "discard unsupported"; |
|
|
|
else if (data_limits->max_discard_sectors < pool->sectors_per_block) |
|
reason = "max discard sectors smaller than a block"; |
|
|
|
if (reason) { |
|
DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason); |
|
pt->adjusted_pf.discard_passdown = false; |
|
} |
|
} |
|
|
|
static int bind_control_target(struct pool *pool, struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
|
|
/* |
|
* We want to make sure that a pool in PM_FAIL mode is never upgraded. |
|
*/ |
|
enum pool_mode old_mode = get_pool_mode(pool); |
|
enum pool_mode new_mode = pt->adjusted_pf.mode; |
|
|
|
/* |
|
* Don't change the pool's mode until set_pool_mode() below. |
|
* Otherwise the pool's process_* function pointers may |
|
* not match the desired pool mode. |
|
*/ |
|
pt->adjusted_pf.mode = old_mode; |
|
|
|
pool->ti = ti; |
|
pool->pf = pt->adjusted_pf; |
|
pool->low_water_blocks = pt->low_water_blocks; |
|
|
|
set_pool_mode(pool, new_mode); |
|
|
|
return 0; |
|
} |
|
|
|
static void unbind_control_target(struct pool *pool, struct dm_target *ti) |
|
{ |
|
if (pool->ti == ti) |
|
pool->ti = NULL; |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Pool creation |
|
*--------------------------------------------------------------*/ |
|
/* Initialize pool features. */ |
|
static void pool_features_init(struct pool_features *pf) |
|
{ |
|
pf->mode = PM_WRITE; |
|
pf->zero_new_blocks = true; |
|
pf->discard_enabled = true; |
|
pf->discard_passdown = true; |
|
pf->error_if_no_space = false; |
|
} |
|
|
|
static void __pool_destroy(struct pool *pool) |
|
{ |
|
__pool_table_remove(pool); |
|
|
|
vfree(pool->cell_sort_array); |
|
if (dm_pool_metadata_close(pool->pmd) < 0) |
|
DMWARN("%s: dm_pool_metadata_close() failed.", __func__); |
|
|
|
dm_bio_prison_destroy(pool->prison); |
|
dm_kcopyd_client_destroy(pool->copier); |
|
|
|
if (pool->wq) |
|
destroy_workqueue(pool->wq); |
|
|
|
if (pool->next_mapping) |
|
mempool_free(pool->next_mapping, &pool->mapping_pool); |
|
mempool_exit(&pool->mapping_pool); |
|
bio_uninit(&pool->flush_bio); |
|
dm_deferred_set_destroy(pool->shared_read_ds); |
|
dm_deferred_set_destroy(pool->all_io_ds); |
|
kfree(pool); |
|
} |
|
|
|
static struct kmem_cache *_new_mapping_cache; |
|
|
|
static struct pool *pool_create(struct mapped_device *pool_md, |
|
struct block_device *metadata_dev, |
|
struct block_device *data_dev, |
|
unsigned long block_size, |
|
int read_only, char **error) |
|
{ |
|
int r; |
|
void *err_p; |
|
struct pool *pool; |
|
struct dm_pool_metadata *pmd; |
|
bool format_device = read_only ? false : true; |
|
|
|
pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device); |
|
if (IS_ERR(pmd)) { |
|
*error = "Error creating metadata object"; |
|
return (struct pool *)pmd; |
|
} |
|
|
|
pool = kzalloc(sizeof(*pool), GFP_KERNEL); |
|
if (!pool) { |
|
*error = "Error allocating memory for pool"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_pool; |
|
} |
|
|
|
pool->pmd = pmd; |
|
pool->sectors_per_block = block_size; |
|
if (block_size & (block_size - 1)) |
|
pool->sectors_per_block_shift = -1; |
|
else |
|
pool->sectors_per_block_shift = __ffs(block_size); |
|
pool->low_water_blocks = 0; |
|
pool_features_init(&pool->pf); |
|
pool->prison = dm_bio_prison_create(); |
|
if (!pool->prison) { |
|
*error = "Error creating pool's bio prison"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_prison; |
|
} |
|
|
|
pool->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); |
|
if (IS_ERR(pool->copier)) { |
|
r = PTR_ERR(pool->copier); |
|
*error = "Error creating pool's kcopyd client"; |
|
err_p = ERR_PTR(r); |
|
goto bad_kcopyd_client; |
|
} |
|
|
|
/* |
|
* Create singlethreaded workqueue that will service all devices |
|
* that use this metadata. |
|
*/ |
|
pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); |
|
if (!pool->wq) { |
|
*error = "Error creating pool's workqueue"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_wq; |
|
} |
|
|
|
throttle_init(&pool->throttle); |
|
INIT_WORK(&pool->worker, do_worker); |
|
INIT_DELAYED_WORK(&pool->waker, do_waker); |
|
INIT_DELAYED_WORK(&pool->no_space_timeout, do_no_space_timeout); |
|
spin_lock_init(&pool->lock); |
|
bio_list_init(&pool->deferred_flush_bios); |
|
bio_list_init(&pool->deferred_flush_completions); |
|
INIT_LIST_HEAD(&pool->prepared_mappings); |
|
INIT_LIST_HEAD(&pool->prepared_discards); |
|
INIT_LIST_HEAD(&pool->prepared_discards_pt2); |
|
INIT_LIST_HEAD(&pool->active_thins); |
|
pool->low_water_triggered = false; |
|
pool->suspended = true; |
|
pool->out_of_data_space = false; |
|
bio_init(&pool->flush_bio, NULL, 0); |
|
|
|
pool->shared_read_ds = dm_deferred_set_create(); |
|
if (!pool->shared_read_ds) { |
|
*error = "Error creating pool's shared read deferred set"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_shared_read_ds; |
|
} |
|
|
|
pool->all_io_ds = dm_deferred_set_create(); |
|
if (!pool->all_io_ds) { |
|
*error = "Error creating pool's all io deferred set"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_all_io_ds; |
|
} |
|
|
|
pool->next_mapping = NULL; |
|
r = mempool_init_slab_pool(&pool->mapping_pool, MAPPING_POOL_SIZE, |
|
_new_mapping_cache); |
|
if (r) { |
|
*error = "Error creating pool's mapping mempool"; |
|
err_p = ERR_PTR(r); |
|
goto bad_mapping_pool; |
|
} |
|
|
|
pool->cell_sort_array = |
|
vmalloc(array_size(CELL_SORT_ARRAY_SIZE, |
|
sizeof(*pool->cell_sort_array))); |
|
if (!pool->cell_sort_array) { |
|
*error = "Error allocating cell sort array"; |
|
err_p = ERR_PTR(-ENOMEM); |
|
goto bad_sort_array; |
|
} |
|
|
|
pool->ref_count = 1; |
|
pool->last_commit_jiffies = jiffies; |
|
pool->pool_md = pool_md; |
|
pool->md_dev = metadata_dev; |
|
pool->data_dev = data_dev; |
|
__pool_table_insert(pool); |
|
|
|
return pool; |
|
|
|
bad_sort_array: |
|
mempool_exit(&pool->mapping_pool); |
|
bad_mapping_pool: |
|
dm_deferred_set_destroy(pool->all_io_ds); |
|
bad_all_io_ds: |
|
dm_deferred_set_destroy(pool->shared_read_ds); |
|
bad_shared_read_ds: |
|
destroy_workqueue(pool->wq); |
|
bad_wq: |
|
dm_kcopyd_client_destroy(pool->copier); |
|
bad_kcopyd_client: |
|
dm_bio_prison_destroy(pool->prison); |
|
bad_prison: |
|
kfree(pool); |
|
bad_pool: |
|
if (dm_pool_metadata_close(pmd)) |
|
DMWARN("%s: dm_pool_metadata_close() failed.", __func__); |
|
|
|
return err_p; |
|
} |
|
|
|
static void __pool_inc(struct pool *pool) |
|
{ |
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
pool->ref_count++; |
|
} |
|
|
|
static void __pool_dec(struct pool *pool) |
|
{ |
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); |
|
BUG_ON(!pool->ref_count); |
|
if (!--pool->ref_count) |
|
__pool_destroy(pool); |
|
} |
|
|
|
static struct pool *__pool_find(struct mapped_device *pool_md, |
|
struct block_device *metadata_dev, |
|
struct block_device *data_dev, |
|
unsigned long block_size, int read_only, |
|
char **error, int *created) |
|
{ |
|
struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev); |
|
|
|
if (pool) { |
|
if (pool->pool_md != pool_md) { |
|
*error = "metadata device already in use by a pool"; |
|
return ERR_PTR(-EBUSY); |
|
} |
|
if (pool->data_dev != data_dev) { |
|
*error = "data device already in use by a pool"; |
|
return ERR_PTR(-EBUSY); |
|
} |
|
__pool_inc(pool); |
|
|
|
} else { |
|
pool = __pool_table_lookup(pool_md); |
|
if (pool) { |
|
if (pool->md_dev != metadata_dev || pool->data_dev != data_dev) { |
|
*error = "different pool cannot replace a pool"; |
|
return ERR_PTR(-EINVAL); |
|
} |
|
__pool_inc(pool); |
|
|
|
} else { |
|
pool = pool_create(pool_md, metadata_dev, data_dev, block_size, read_only, error); |
|
*created = 1; |
|
} |
|
} |
|
|
|
return pool; |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Pool target methods |
|
*--------------------------------------------------------------*/ |
|
static void pool_dtr(struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
|
|
mutex_lock(&dm_thin_pool_table.mutex); |
|
|
|
unbind_control_target(pt->pool, ti); |
|
__pool_dec(pt->pool); |
|
dm_put_device(ti, pt->metadata_dev); |
|
dm_put_device(ti, pt->data_dev); |
|
kfree(pt); |
|
|
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
} |
|
|
|
static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, |
|
struct dm_target *ti) |
|
{ |
|
int r; |
|
unsigned argc; |
|
const char *arg_name; |
|
|
|
static const struct dm_arg _args[] = { |
|
{0, 4, "Invalid number of pool feature arguments"}, |
|
}; |
|
|
|
/* |
|
* No feature arguments supplied. |
|
*/ |
|
if (!as->argc) |
|
return 0; |
|
|
|
r = dm_read_arg_group(_args, as, &argc, &ti->error); |
|
if (r) |
|
return -EINVAL; |
|
|
|
while (argc && !r) { |
|
arg_name = dm_shift_arg(as); |
|
argc--; |
|
|
|
if (!strcasecmp(arg_name, "skip_block_zeroing")) |
|
pf->zero_new_blocks = false; |
|
|
|
else if (!strcasecmp(arg_name, "ignore_discard")) |
|
pf->discard_enabled = false; |
|
|
|
else if (!strcasecmp(arg_name, "no_discard_passdown")) |
|
pf->discard_passdown = false; |
|
|
|
else if (!strcasecmp(arg_name, "read_only")) |
|
pf->mode = PM_READ_ONLY; |
|
|
|
else if (!strcasecmp(arg_name, "error_if_no_space")) |
|
pf->error_if_no_space = true; |
|
|
|
else { |
|
ti->error = "Unrecognised pool feature requested"; |
|
r = -EINVAL; |
|
break; |
|
} |
|
} |
|
|
|
return r; |
|
} |
|
|
|
static void metadata_low_callback(void *context) |
|
{ |
|
struct pool *pool = context; |
|
|
|
DMWARN("%s: reached low water mark for metadata device: sending event.", |
|
dm_device_name(pool->pool_md)); |
|
|
|
dm_table_event(pool->ti->table); |
|
} |
|
|
|
/* |
|
* We need to flush the data device **before** committing the metadata. |
|
* |
|
* This ensures that the data blocks of any newly inserted mappings are |
|
* properly written to non-volatile storage and won't be lost in case of a |
|
* crash. |
|
* |
|
* Failure to do so can result in data corruption in the case of internal or |
|
* external snapshots and in the case of newly provisioned blocks, when block |
|
* zeroing is enabled. |
|
*/ |
|
static int metadata_pre_commit_callback(void *context) |
|
{ |
|
struct pool *pool = context; |
|
struct bio *flush_bio = &pool->flush_bio; |
|
|
|
bio_reset(flush_bio); |
|
bio_set_dev(flush_bio, pool->data_dev); |
|
flush_bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; |
|
|
|
return submit_bio_wait(flush_bio); |
|
} |
|
|
|
static sector_t get_dev_size(struct block_device *bdev) |
|
{ |
|
return i_size_read(bdev->bd_inode) >> SECTOR_SHIFT; |
|
} |
|
|
|
static void warn_if_metadata_device_too_big(struct block_device *bdev) |
|
{ |
|
sector_t metadata_dev_size = get_dev_size(bdev); |
|
char buffer[BDEVNAME_SIZE]; |
|
|
|
if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) |
|
DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", |
|
bdevname(bdev, buffer), THIN_METADATA_MAX_SECTORS); |
|
} |
|
|
|
static sector_t get_metadata_dev_size(struct block_device *bdev) |
|
{ |
|
sector_t metadata_dev_size = get_dev_size(bdev); |
|
|
|
if (metadata_dev_size > THIN_METADATA_MAX_SECTORS) |
|
metadata_dev_size = THIN_METADATA_MAX_SECTORS; |
|
|
|
return metadata_dev_size; |
|
} |
|
|
|
static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev) |
|
{ |
|
sector_t metadata_dev_size = get_metadata_dev_size(bdev); |
|
|
|
sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE); |
|
|
|
return metadata_dev_size; |
|
} |
|
|
|
/* |
|
* When a metadata threshold is crossed a dm event is triggered, and |
|
* userland should respond by growing the metadata device. We could let |
|
* userland set the threshold, like we do with the data threshold, but I'm |
|
* not sure they know enough to do this well. |
|
*/ |
|
static dm_block_t calc_metadata_threshold(struct pool_c *pt) |
|
{ |
|
/* |
|
* 4M is ample for all ops with the possible exception of thin |
|
* device deletion which is harmless if it fails (just retry the |
|
* delete after you've grown the device). |
|
*/ |
|
dm_block_t quarter = get_metadata_dev_size_in_blocks(pt->metadata_dev->bdev) / 4; |
|
return min((dm_block_t)1024ULL /* 4M */, quarter); |
|
} |
|
|
|
/* |
|
* thin-pool <metadata dev> <data dev> |
|
* <data block size (sectors)> |
|
* <low water mark (blocks)> |
|
* [<#feature args> [<arg>]*] |
|
* |
|
* Optional feature arguments are: |
|
* skip_block_zeroing: skips the zeroing of newly-provisioned blocks. |
|
* ignore_discard: disable discard |
|
* no_discard_passdown: don't pass discards down to the data device |
|
* read_only: Don't allow any changes to be made to the pool metadata. |
|
* error_if_no_space: error IOs, instead of queueing, if no space. |
|
*/ |
|
static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) |
|
{ |
|
int r, pool_created = 0; |
|
struct pool_c *pt; |
|
struct pool *pool; |
|
struct pool_features pf; |
|
struct dm_arg_set as; |
|
struct dm_dev *data_dev; |
|
unsigned long block_size; |
|
dm_block_t low_water_blocks; |
|
struct dm_dev *metadata_dev; |
|
fmode_t metadata_mode; |
|
|
|
/* |
|
* FIXME Remove validation from scope of lock. |
|
*/ |
|
mutex_lock(&dm_thin_pool_table.mutex); |
|
|
|
if (argc < 4) { |
|
ti->error = "Invalid argument count"; |
|
r = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
as.argc = argc; |
|
as.argv = argv; |
|
|
|
/* make sure metadata and data are different devices */ |
|
if (!strcmp(argv[0], argv[1])) { |
|
ti->error = "Error setting metadata or data device"; |
|
r = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
/* |
|
* Set default pool features. |
|
*/ |
|
pool_features_init(&pf); |
|
|
|
dm_consume_args(&as, 4); |
|
r = parse_pool_features(&as, &pf, ti); |
|
if (r) |
|
goto out_unlock; |
|
|
|
metadata_mode = FMODE_READ | ((pf.mode == PM_READ_ONLY) ? 0 : FMODE_WRITE); |
|
r = dm_get_device(ti, argv[0], metadata_mode, &metadata_dev); |
|
if (r) { |
|
ti->error = "Error opening metadata block device"; |
|
goto out_unlock; |
|
} |
|
warn_if_metadata_device_too_big(metadata_dev->bdev); |
|
|
|
r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev); |
|
if (r) { |
|
ti->error = "Error getting data device"; |
|
goto out_metadata; |
|
} |
|
|
|
if (kstrtoul(argv[2], 10, &block_size) || !block_size || |
|
block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || |
|
block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || |
|
block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { |
|
ti->error = "Invalid block size"; |
|
r = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) { |
|
ti->error = "Invalid low water mark"; |
|
r = -EINVAL; |
|
goto out; |
|
} |
|
|
|
pt = kzalloc(sizeof(*pt), GFP_KERNEL); |
|
if (!pt) { |
|
r = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, data_dev->bdev, |
|
block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created); |
|
if (IS_ERR(pool)) { |
|
r = PTR_ERR(pool); |
|
goto out_free_pt; |
|
} |
|
|
|
/* |
|
* 'pool_created' reflects whether this is the first table load. |
|
* Top level discard support is not allowed to be changed after |
|
* initial load. This would require a pool reload to trigger thin |
|
* device changes. |
|
*/ |
|
if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) { |
|
ti->error = "Discard support cannot be disabled once enabled"; |
|
r = -EINVAL; |
|
goto out_flags_changed; |
|
} |
|
|
|
pt->pool = pool; |
|
pt->ti = ti; |
|
pt->metadata_dev = metadata_dev; |
|
pt->data_dev = data_dev; |
|
pt->low_water_blocks = low_water_blocks; |
|
pt->adjusted_pf = pt->requested_pf = pf; |
|
ti->num_flush_bios = 1; |
|
|
|
/* |
|
* Only need to enable discards if the pool should pass |
|
* them down to the data device. The thin device's discard |
|
* processing will cause mappings to be removed from the btree. |
|
*/ |
|
if (pf.discard_enabled && pf.discard_passdown) { |
|
ti->num_discard_bios = 1; |
|
|
|
/* |
|
* Setting 'discards_supported' circumvents the normal |
|
* stacking of discard limits (this keeps the pool and |
|
* thin devices' discard limits consistent). |
|
*/ |
|
ti->discards_supported = true; |
|
} |
|
ti->private = pt; |
|
|
|
r = dm_pool_register_metadata_threshold(pt->pool->pmd, |
|
calc_metadata_threshold(pt), |
|
metadata_low_callback, |
|
pool); |
|
if (r) |
|
goto out_flags_changed; |
|
|
|
dm_pool_register_pre_commit_callback(pool->pmd, |
|
metadata_pre_commit_callback, pool); |
|
|
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
|
|
return 0; |
|
|
|
out_flags_changed: |
|
__pool_dec(pool); |
|
out_free_pt: |
|
kfree(pt); |
|
out: |
|
dm_put_device(ti, data_dev); |
|
out_metadata: |
|
dm_put_device(ti, metadata_dev); |
|
out_unlock: |
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
|
|
return r; |
|
} |
|
|
|
static int pool_map(struct dm_target *ti, struct bio *bio) |
|
{ |
|
int r; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
/* |
|
* As this is a singleton target, ti->begin is always zero. |
|
*/ |
|
spin_lock_irq(&pool->lock); |
|
bio_set_dev(bio, pt->data_dev->bdev); |
|
r = DM_MAPIO_REMAPPED; |
|
spin_unlock_irq(&pool->lock); |
|
|
|
return r; |
|
} |
|
|
|
static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit) |
|
{ |
|
int r; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
sector_t data_size = ti->len; |
|
dm_block_t sb_data_size; |
|
|
|
*need_commit = false; |
|
|
|
(void) sector_div(data_size, pool->sectors_per_block); |
|
|
|
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size); |
|
if (r) { |
|
DMERR("%s: failed to retrieve data device size", |
|
dm_device_name(pool->pool_md)); |
|
return r; |
|
} |
|
|
|
if (data_size < sb_data_size) { |
|
DMERR("%s: pool target (%llu blocks) too small: expected %llu", |
|
dm_device_name(pool->pool_md), |
|
(unsigned long long)data_size, sb_data_size); |
|
return -EINVAL; |
|
|
|
} else if (data_size > sb_data_size) { |
|
if (dm_pool_metadata_needs_check(pool->pmd)) { |
|
DMERR("%s: unable to grow the data device until repaired.", |
|
dm_device_name(pool->pool_md)); |
|
return 0; |
|
} |
|
|
|
if (sb_data_size) |
|
DMINFO("%s: growing the data device from %llu to %llu blocks", |
|
dm_device_name(pool->pool_md), |
|
sb_data_size, (unsigned long long)data_size); |
|
r = dm_pool_resize_data_dev(pool->pmd, data_size); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_resize_data_dev", r); |
|
return r; |
|
} |
|
|
|
*need_commit = true; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit) |
|
{ |
|
int r; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
dm_block_t metadata_dev_size, sb_metadata_dev_size; |
|
|
|
*need_commit = false; |
|
|
|
metadata_dev_size = get_metadata_dev_size_in_blocks(pool->md_dev); |
|
|
|
r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size); |
|
if (r) { |
|
DMERR("%s: failed to retrieve metadata device size", |
|
dm_device_name(pool->pool_md)); |
|
return r; |
|
} |
|
|
|
if (metadata_dev_size < sb_metadata_dev_size) { |
|
DMERR("%s: metadata device (%llu blocks) too small: expected %llu", |
|
dm_device_name(pool->pool_md), |
|
metadata_dev_size, sb_metadata_dev_size); |
|
return -EINVAL; |
|
|
|
} else if (metadata_dev_size > sb_metadata_dev_size) { |
|
if (dm_pool_metadata_needs_check(pool->pmd)) { |
|
DMERR("%s: unable to grow the metadata device until repaired.", |
|
dm_device_name(pool->pool_md)); |
|
return 0; |
|
} |
|
|
|
warn_if_metadata_device_too_big(pool->md_dev); |
|
DMINFO("%s: growing the metadata device from %llu to %llu blocks", |
|
dm_device_name(pool->pool_md), |
|
sb_metadata_dev_size, metadata_dev_size); |
|
|
|
if (get_pool_mode(pool) == PM_OUT_OF_METADATA_SPACE) |
|
set_pool_mode(pool, PM_WRITE); |
|
|
|
r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size); |
|
if (r) { |
|
metadata_operation_failed(pool, "dm_pool_resize_metadata_dev", r); |
|
return r; |
|
} |
|
|
|
*need_commit = true; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Retrieves the number of blocks of the data device from |
|
* the superblock and compares it to the actual device size, |
|
* thus resizing the data device in case it has grown. |
|
* |
|
* This both copes with opening preallocated data devices in the ctr |
|
* being followed by a resume |
|
* -and- |
|
* calling the resume method individually after userspace has |
|
* grown the data device in reaction to a table event. |
|
*/ |
|
static int pool_preresume(struct dm_target *ti) |
|
{ |
|
int r; |
|
bool need_commit1, need_commit2; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
/* |
|
* Take control of the pool object. |
|
*/ |
|
r = bind_control_target(pool, ti); |
|
if (r) |
|
return r; |
|
|
|
r = maybe_resize_data_dev(ti, &need_commit1); |
|
if (r) |
|
return r; |
|
|
|
r = maybe_resize_metadata_dev(ti, &need_commit2); |
|
if (r) |
|
return r; |
|
|
|
if (need_commit1 || need_commit2) |
|
(void) commit(pool); |
|
|
|
return 0; |
|
} |
|
|
|
static void pool_suspend_active_thins(struct pool *pool) |
|
{ |
|
struct thin_c *tc; |
|
|
|
/* Suspend all active thin devices */ |
|
tc = get_first_thin(pool); |
|
while (tc) { |
|
dm_internal_suspend_noflush(tc->thin_md); |
|
tc = get_next_thin(pool, tc); |
|
} |
|
} |
|
|
|
static void pool_resume_active_thins(struct pool *pool) |
|
{ |
|
struct thin_c *tc; |
|
|
|
/* Resume all active thin devices */ |
|
tc = get_first_thin(pool); |
|
while (tc) { |
|
dm_internal_resume(tc->thin_md); |
|
tc = get_next_thin(pool, tc); |
|
} |
|
} |
|
|
|
static void pool_resume(struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
/* |
|
* Must requeue active_thins' bios and then resume |
|
* active_thins _before_ clearing 'suspend' flag. |
|
*/ |
|
requeue_bios(pool); |
|
pool_resume_active_thins(pool); |
|
|
|
spin_lock_irq(&pool->lock); |
|
pool->low_water_triggered = false; |
|
pool->suspended = false; |
|
spin_unlock_irq(&pool->lock); |
|
|
|
do_waker(&pool->waker.work); |
|
} |
|
|
|
static void pool_presuspend(struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
spin_lock_irq(&pool->lock); |
|
pool->suspended = true; |
|
spin_unlock_irq(&pool->lock); |
|
|
|
pool_suspend_active_thins(pool); |
|
} |
|
|
|
static void pool_presuspend_undo(struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
pool_resume_active_thins(pool); |
|
|
|
spin_lock_irq(&pool->lock); |
|
pool->suspended = false; |
|
spin_unlock_irq(&pool->lock); |
|
} |
|
|
|
static void pool_postsuspend(struct dm_target *ti) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
cancel_delayed_work_sync(&pool->waker); |
|
cancel_delayed_work_sync(&pool->no_space_timeout); |
|
flush_workqueue(pool->wq); |
|
(void) commit(pool); |
|
} |
|
|
|
static int check_arg_count(unsigned argc, unsigned args_required) |
|
{ |
|
if (argc != args_required) { |
|
DMWARN("Message received with %u arguments instead of %u.", |
|
argc, args_required); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning) |
|
{ |
|
if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) && |
|
*dev_id <= MAX_DEV_ID) |
|
return 0; |
|
|
|
if (warning) |
|
DMWARN("Message received with invalid device id: %s", arg); |
|
|
|
return -EINVAL; |
|
} |
|
|
|
static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
dm_thin_id dev_id; |
|
int r; |
|
|
|
r = check_arg_count(argc, 2); |
|
if (r) |
|
return r; |
|
|
|
r = read_dev_id(argv[1], &dev_id, 1); |
|
if (r) |
|
return r; |
|
|
|
r = dm_pool_create_thin(pool->pmd, dev_id); |
|
if (r) { |
|
DMWARN("Creation of new thinly-provisioned device with id %s failed.", |
|
argv[1]); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
dm_thin_id dev_id; |
|
dm_thin_id origin_dev_id; |
|
int r; |
|
|
|
r = check_arg_count(argc, 3); |
|
if (r) |
|
return r; |
|
|
|
r = read_dev_id(argv[1], &dev_id, 1); |
|
if (r) |
|
return r; |
|
|
|
r = read_dev_id(argv[2], &origin_dev_id, 1); |
|
if (r) |
|
return r; |
|
|
|
r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id); |
|
if (r) { |
|
DMWARN("Creation of new snapshot %s of device %s failed.", |
|
argv[1], argv[2]); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
dm_thin_id dev_id; |
|
int r; |
|
|
|
r = check_arg_count(argc, 2); |
|
if (r) |
|
return r; |
|
|
|
r = read_dev_id(argv[1], &dev_id, 1); |
|
if (r) |
|
return r; |
|
|
|
r = dm_pool_delete_thin_device(pool->pmd, dev_id); |
|
if (r) |
|
DMWARN("Deletion of thin device %s failed.", argv[1]); |
|
|
|
return r; |
|
} |
|
|
|
static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
dm_thin_id old_id, new_id; |
|
int r; |
|
|
|
r = check_arg_count(argc, 3); |
|
if (r) |
|
return r; |
|
|
|
if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) { |
|
DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]); |
|
return -EINVAL; |
|
} |
|
|
|
if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) { |
|
DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]); |
|
return -EINVAL; |
|
} |
|
|
|
r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id); |
|
if (r) { |
|
DMWARN("Failed to change transaction id from %s to %s.", |
|
argv[1], argv[2]); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
int r; |
|
|
|
r = check_arg_count(argc, 1); |
|
if (r) |
|
return r; |
|
|
|
(void) commit(pool); |
|
|
|
r = dm_pool_reserve_metadata_snap(pool->pmd); |
|
if (r) |
|
DMWARN("reserve_metadata_snap message failed."); |
|
|
|
return r; |
|
} |
|
|
|
static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool) |
|
{ |
|
int r; |
|
|
|
r = check_arg_count(argc, 1); |
|
if (r) |
|
return r; |
|
|
|
r = dm_pool_release_metadata_snap(pool->pmd); |
|
if (r) |
|
DMWARN("release_metadata_snap message failed."); |
|
|
|
return r; |
|
} |
|
|
|
/* |
|
* Messages supported: |
|
* create_thin <dev_id> |
|
* create_snap <dev_id> <origin_id> |
|
* delete <dev_id> |
|
* set_transaction_id <current_trans_id> <new_trans_id> |
|
* reserve_metadata_snap |
|
* release_metadata_snap |
|
*/ |
|
static int pool_message(struct dm_target *ti, unsigned argc, char **argv, |
|
char *result, unsigned maxlen) |
|
{ |
|
int r = -EINVAL; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE) { |
|
DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode", |
|
dm_device_name(pool->pool_md)); |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
if (!strcasecmp(argv[0], "create_thin")) |
|
r = process_create_thin_mesg(argc, argv, pool); |
|
|
|
else if (!strcasecmp(argv[0], "create_snap")) |
|
r = process_create_snap_mesg(argc, argv, pool); |
|
|
|
else if (!strcasecmp(argv[0], "delete")) |
|
r = process_delete_mesg(argc, argv, pool); |
|
|
|
else if (!strcasecmp(argv[0], "set_transaction_id")) |
|
r = process_set_transaction_id_mesg(argc, argv, pool); |
|
|
|
else if (!strcasecmp(argv[0], "reserve_metadata_snap")) |
|
r = process_reserve_metadata_snap_mesg(argc, argv, pool); |
|
|
|
else if (!strcasecmp(argv[0], "release_metadata_snap")) |
|
r = process_release_metadata_snap_mesg(argc, argv, pool); |
|
|
|
else |
|
DMWARN("Unrecognised thin pool target message received: %s", argv[0]); |
|
|
|
if (!r) |
|
(void) commit(pool); |
|
|
|
return r; |
|
} |
|
|
|
static void emit_flags(struct pool_features *pf, char *result, |
|
unsigned sz, unsigned maxlen) |
|
{ |
|
unsigned count = !pf->zero_new_blocks + !pf->discard_enabled + |
|
!pf->discard_passdown + (pf->mode == PM_READ_ONLY) + |
|
pf->error_if_no_space; |
|
DMEMIT("%u ", count); |
|
|
|
if (!pf->zero_new_blocks) |
|
DMEMIT("skip_block_zeroing "); |
|
|
|
if (!pf->discard_enabled) |
|
DMEMIT("ignore_discard "); |
|
|
|
if (!pf->discard_passdown) |
|
DMEMIT("no_discard_passdown "); |
|
|
|
if (pf->mode == PM_READ_ONLY) |
|
DMEMIT("read_only "); |
|
|
|
if (pf->error_if_no_space) |
|
DMEMIT("error_if_no_space "); |
|
} |
|
|
|
/* |
|
* Status line is: |
|
* <transaction id> <used metadata sectors>/<total metadata sectors> |
|
* <used data sectors>/<total data sectors> <held metadata root> |
|
* <pool mode> <discard config> <no space config> <needs_check> |
|
*/ |
|
static void pool_status(struct dm_target *ti, status_type_t type, |
|
unsigned status_flags, char *result, unsigned maxlen) |
|
{ |
|
int r; |
|
unsigned sz = 0; |
|
uint64_t transaction_id; |
|
dm_block_t nr_free_blocks_data; |
|
dm_block_t nr_free_blocks_metadata; |
|
dm_block_t nr_blocks_data; |
|
dm_block_t nr_blocks_metadata; |
|
dm_block_t held_root; |
|
enum pool_mode mode; |
|
char buf[BDEVNAME_SIZE]; |
|
char buf2[BDEVNAME_SIZE]; |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
|
|
switch (type) { |
|
case STATUSTYPE_INFO: |
|
if (get_pool_mode(pool) == PM_FAIL) { |
|
DMEMIT("Fail"); |
|
break; |
|
} |
|
|
|
/* Commit to ensure statistics aren't out-of-date */ |
|
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) |
|
(void) commit(pool); |
|
|
|
r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_metadata_transaction_id returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_free_metadata_block_count returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_metadata_dev_size returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_free_block_count returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_data_dev_size returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
r = dm_pool_get_metadata_snap(pool->pmd, &held_root); |
|
if (r) { |
|
DMERR("%s: dm_pool_get_metadata_snap returned %d", |
|
dm_device_name(pool->pool_md), r); |
|
goto err; |
|
} |
|
|
|
DMEMIT("%llu %llu/%llu %llu/%llu ", |
|
(unsigned long long)transaction_id, |
|
(unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
|
(unsigned long long)nr_blocks_metadata, |
|
(unsigned long long)(nr_blocks_data - nr_free_blocks_data), |
|
(unsigned long long)nr_blocks_data); |
|
|
|
if (held_root) |
|
DMEMIT("%llu ", held_root); |
|
else |
|
DMEMIT("- "); |
|
|
|
mode = get_pool_mode(pool); |
|
if (mode == PM_OUT_OF_DATA_SPACE) |
|
DMEMIT("out_of_data_space "); |
|
else if (is_read_only_pool_mode(mode)) |
|
DMEMIT("ro "); |
|
else |
|
DMEMIT("rw "); |
|
|
|
if (!pool->pf.discard_enabled) |
|
DMEMIT("ignore_discard "); |
|
else if (pool->pf.discard_passdown) |
|
DMEMIT("discard_passdown "); |
|
else |
|
DMEMIT("no_discard_passdown "); |
|
|
|
if (pool->pf.error_if_no_space) |
|
DMEMIT("error_if_no_space "); |
|
else |
|
DMEMIT("queue_if_no_space "); |
|
|
|
if (dm_pool_metadata_needs_check(pool->pmd)) |
|
DMEMIT("needs_check "); |
|
else |
|
DMEMIT("- "); |
|
|
|
DMEMIT("%llu ", (unsigned long long)calc_metadata_threshold(pt)); |
|
|
|
break; |
|
|
|
case STATUSTYPE_TABLE: |
|
DMEMIT("%s %s %lu %llu ", |
|
format_dev_t(buf, pt->metadata_dev->bdev->bd_dev), |
|
format_dev_t(buf2, pt->data_dev->bdev->bd_dev), |
|
(unsigned long)pool->sectors_per_block, |
|
(unsigned long long)pt->low_water_blocks); |
|
emit_flags(&pt->requested_pf, result, sz, maxlen); |
|
break; |
|
} |
|
return; |
|
|
|
err: |
|
DMEMIT("Error"); |
|
} |
|
|
|
static int pool_iterate_devices(struct dm_target *ti, |
|
iterate_devices_callout_fn fn, void *data) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
|
|
return fn(ti, pt->data_dev, 0, ti->len, data); |
|
} |
|
|
|
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) |
|
{ |
|
struct pool_c *pt = ti->private; |
|
struct pool *pool = pt->pool; |
|
sector_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
|
|
|
/* |
|
* If max_sectors is smaller than pool->sectors_per_block adjust it |
|
* to the highest possible power-of-2 factor of pool->sectors_per_block. |
|
* This is especially beneficial when the pool's data device is a RAID |
|
* device that has a full stripe width that matches pool->sectors_per_block |
|
* -- because even though partial RAID stripe-sized IOs will be issued to a |
|
* single RAID stripe; when aggregated they will end on a full RAID stripe |
|
* boundary.. which avoids additional partial RAID stripe writes cascading |
|
*/ |
|
if (limits->max_sectors < pool->sectors_per_block) { |
|
while (!is_factor(pool->sectors_per_block, limits->max_sectors)) { |
|
if ((limits->max_sectors & (limits->max_sectors - 1)) == 0) |
|
limits->max_sectors--; |
|
limits->max_sectors = rounddown_pow_of_two(limits->max_sectors); |
|
} |
|
} |
|
|
|
/* |
|
* If the system-determined stacked limits are compatible with the |
|
* pool's blocksize (io_opt is a factor) do not override them. |
|
*/ |
|
if (io_opt_sectors < pool->sectors_per_block || |
|
!is_factor(io_opt_sectors, pool->sectors_per_block)) { |
|
if (is_factor(pool->sectors_per_block, limits->max_sectors)) |
|
blk_limits_io_min(limits, limits->max_sectors << SECTOR_SHIFT); |
|
else |
|
blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT); |
|
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); |
|
} |
|
|
|
/* |
|
* pt->adjusted_pf is a staging area for the actual features to use. |
|
* They get transferred to the live pool in bind_control_target() |
|
* called from pool_preresume(). |
|
*/ |
|
if (!pt->adjusted_pf.discard_enabled) { |
|
/* |
|
* Must explicitly disallow stacking discard limits otherwise the |
|
* block layer will stack them if pool's data device has support. |
|
* QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the |
|
* user to see that, so make sure to set all discard limits to 0. |
|
*/ |
|
limits->discard_granularity = 0; |
|
return; |
|
} |
|
|
|
disable_passdown_if_not_supported(pt); |
|
|
|
/* |
|
* The pool uses the same discard limits as the underlying data |
|
* device. DM core has already set this up. |
|
*/ |
|
} |
|
|
|
static struct target_type pool_target = { |
|
.name = "thin-pool", |
|
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE | |
|
DM_TARGET_IMMUTABLE, |
|
.version = {1, 22, 0}, |
|
.module = THIS_MODULE, |
|
.ctr = pool_ctr, |
|
.dtr = pool_dtr, |
|
.map = pool_map, |
|
.presuspend = pool_presuspend, |
|
.presuspend_undo = pool_presuspend_undo, |
|
.postsuspend = pool_postsuspend, |
|
.preresume = pool_preresume, |
|
.resume = pool_resume, |
|
.message = pool_message, |
|
.status = pool_status, |
|
.iterate_devices = pool_iterate_devices, |
|
.io_hints = pool_io_hints, |
|
}; |
|
|
|
/*---------------------------------------------------------------- |
|
* Thin target methods |
|
*--------------------------------------------------------------*/ |
|
static void thin_get(struct thin_c *tc) |
|
{ |
|
refcount_inc(&tc->refcount); |
|
} |
|
|
|
static void thin_put(struct thin_c *tc) |
|
{ |
|
if (refcount_dec_and_test(&tc->refcount)) |
|
complete(&tc->can_destroy); |
|
} |
|
|
|
static void thin_dtr(struct dm_target *ti) |
|
{ |
|
struct thin_c *tc = ti->private; |
|
|
|
spin_lock_irq(&tc->pool->lock); |
|
list_del_rcu(&tc->list); |
|
spin_unlock_irq(&tc->pool->lock); |
|
synchronize_rcu(); |
|
|
|
thin_put(tc); |
|
wait_for_completion(&tc->can_destroy); |
|
|
|
mutex_lock(&dm_thin_pool_table.mutex); |
|
|
|
__pool_dec(tc->pool); |
|
dm_pool_close_thin_device(tc->td); |
|
dm_put_device(ti, tc->pool_dev); |
|
if (tc->origin_dev) |
|
dm_put_device(ti, tc->origin_dev); |
|
kfree(tc); |
|
|
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
} |
|
|
|
/* |
|
* Thin target parameters: |
|
* |
|
* <pool_dev> <dev_id> [origin_dev] |
|
* |
|
* pool_dev: the path to the pool (eg, /dev/mapper/my_pool) |
|
* dev_id: the internal device identifier |
|
* origin_dev: a device external to the pool that should act as the origin |
|
* |
|
* If the pool device has discards disabled, they get disabled for the thin |
|
* device as well. |
|
*/ |
|
static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) |
|
{ |
|
int r; |
|
struct thin_c *tc; |
|
struct dm_dev *pool_dev, *origin_dev; |
|
struct mapped_device *pool_md; |
|
|
|
mutex_lock(&dm_thin_pool_table.mutex); |
|
|
|
if (argc != 2 && argc != 3) { |
|
ti->error = "Invalid argument count"; |
|
r = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL); |
|
if (!tc) { |
|
ti->error = "Out of memory"; |
|
r = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
tc->thin_md = dm_table_get_md(ti->table); |
|
spin_lock_init(&tc->lock); |
|
INIT_LIST_HEAD(&tc->deferred_cells); |
|
bio_list_init(&tc->deferred_bio_list); |
|
bio_list_init(&tc->retry_on_resume_list); |
|
tc->sort_bio_list = RB_ROOT; |
|
|
|
if (argc == 3) { |
|
if (!strcmp(argv[0], argv[2])) { |
|
ti->error = "Error setting origin device"; |
|
r = -EINVAL; |
|
goto bad_origin_dev; |
|
} |
|
|
|
r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev); |
|
if (r) { |
|
ti->error = "Error opening origin device"; |
|
goto bad_origin_dev; |
|
} |
|
tc->origin_dev = origin_dev; |
|
} |
|
|
|
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev); |
|
if (r) { |
|
ti->error = "Error opening pool device"; |
|
goto bad_pool_dev; |
|
} |
|
tc->pool_dev = pool_dev; |
|
|
|
if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) { |
|
ti->error = "Invalid device id"; |
|
r = -EINVAL; |
|
goto bad_common; |
|
} |
|
|
|
pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev); |
|
if (!pool_md) { |
|
ti->error = "Couldn't get pool mapped device"; |
|
r = -EINVAL; |
|
goto bad_common; |
|
} |
|
|
|
tc->pool = __pool_table_lookup(pool_md); |
|
if (!tc->pool) { |
|
ti->error = "Couldn't find pool object"; |
|
r = -EINVAL; |
|
goto bad_pool_lookup; |
|
} |
|
__pool_inc(tc->pool); |
|
|
|
if (get_pool_mode(tc->pool) == PM_FAIL) { |
|
ti->error = "Couldn't open thin device, Pool is in fail mode"; |
|
r = -EINVAL; |
|
goto bad_pool; |
|
} |
|
|
|
r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td); |
|
if (r) { |
|
ti->error = "Couldn't open thin internal device"; |
|
goto bad_pool; |
|
} |
|
|
|
r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block); |
|
if (r) |
|
goto bad; |
|
|
|
ti->num_flush_bios = 1; |
|
ti->flush_supported = true; |
|
ti->per_io_data_size = sizeof(struct dm_thin_endio_hook); |
|
|
|
/* In case the pool supports discards, pass them on. */ |
|
if (tc->pool->pf.discard_enabled) { |
|
ti->discards_supported = true; |
|
ti->num_discard_bios = 1; |
|
} |
|
|
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
|
|
spin_lock_irq(&tc->pool->lock); |
|
if (tc->pool->suspended) { |
|
spin_unlock_irq(&tc->pool->lock); |
|
mutex_lock(&dm_thin_pool_table.mutex); /* reacquire for __pool_dec */ |
|
ti->error = "Unable to activate thin device while pool is suspended"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
refcount_set(&tc->refcount, 1); |
|
init_completion(&tc->can_destroy); |
|
list_add_tail_rcu(&tc->list, &tc->pool->active_thins); |
|
spin_unlock_irq(&tc->pool->lock); |
|
/* |
|
* This synchronize_rcu() call is needed here otherwise we risk a |
|
* wake_worker() call finding no bios to process (because the newly |
|
* added tc isn't yet visible). So this reduces latency since we |
|
* aren't then dependent on the periodic commit to wake_worker(). |
|
*/ |
|
synchronize_rcu(); |
|
|
|
dm_put(pool_md); |
|
|
|
return 0; |
|
|
|
bad: |
|
dm_pool_close_thin_device(tc->td); |
|
bad_pool: |
|
__pool_dec(tc->pool); |
|
bad_pool_lookup: |
|
dm_put(pool_md); |
|
bad_common: |
|
dm_put_device(ti, tc->pool_dev); |
|
bad_pool_dev: |
|
if (tc->origin_dev) |
|
dm_put_device(ti, tc->origin_dev); |
|
bad_origin_dev: |
|
kfree(tc); |
|
out_unlock: |
|
mutex_unlock(&dm_thin_pool_table.mutex); |
|
|
|
return r; |
|
} |
|
|
|
static int thin_map(struct dm_target *ti, struct bio *bio) |
|
{ |
|
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector); |
|
|
|
return thin_bio_map(ti, bio); |
|
} |
|
|
|
static int thin_endio(struct dm_target *ti, struct bio *bio, |
|
blk_status_t *err) |
|
{ |
|
unsigned long flags; |
|
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); |
|
struct list_head work; |
|
struct dm_thin_new_mapping *m, *tmp; |
|
struct pool *pool = h->tc->pool; |
|
|
|
if (h->shared_read_entry) { |
|
INIT_LIST_HEAD(&work); |
|
dm_deferred_entry_dec(h->shared_read_entry, &work); |
|
|
|
spin_lock_irqsave(&pool->lock, flags); |
|
list_for_each_entry_safe(m, tmp, &work, list) { |
|
list_del(&m->list); |
|
__complete_mapping_preparation(m); |
|
} |
|
spin_unlock_irqrestore(&pool->lock, flags); |
|
} |
|
|
|
if (h->all_io_entry) { |
|
INIT_LIST_HEAD(&work); |
|
dm_deferred_entry_dec(h->all_io_entry, &work); |
|
if (!list_empty(&work)) { |
|
spin_lock_irqsave(&pool->lock, flags); |
|
list_for_each_entry_safe(m, tmp, &work, list) |
|
list_add_tail(&m->list, &pool->prepared_discards); |
|
spin_unlock_irqrestore(&pool->lock, flags); |
|
wake_worker(pool); |
|
} |
|
} |
|
|
|
if (h->cell) |
|
cell_defer_no_holder(h->tc, h->cell); |
|
|
|
return DM_ENDIO_DONE; |
|
} |
|
|
|
static void thin_presuspend(struct dm_target *ti) |
|
{ |
|
struct thin_c *tc = ti->private; |
|
|
|
if (dm_noflush_suspending(ti)) |
|
noflush_work(tc, do_noflush_start); |
|
} |
|
|
|
static void thin_postsuspend(struct dm_target *ti) |
|
{ |
|
struct thin_c *tc = ti->private; |
|
|
|
/* |
|
* The dm_noflush_suspending flag has been cleared by now, so |
|
* unfortunately we must always run this. |
|
*/ |
|
noflush_work(tc, do_noflush_stop); |
|
} |
|
|
|
static int thin_preresume(struct dm_target *ti) |
|
{ |
|
struct thin_c *tc = ti->private; |
|
|
|
if (tc->origin_dev) |
|
tc->origin_size = get_dev_size(tc->origin_dev->bdev); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* <nr mapped sectors> <highest mapped sector> |
|
*/ |
|
static void thin_status(struct dm_target *ti, status_type_t type, |
|
unsigned status_flags, char *result, unsigned maxlen) |
|
{ |
|
int r; |
|
ssize_t sz = 0; |
|
dm_block_t mapped, highest; |
|
char buf[BDEVNAME_SIZE]; |
|
struct thin_c *tc = ti->private; |
|
|
|
if (get_pool_mode(tc->pool) == PM_FAIL) { |
|
DMEMIT("Fail"); |
|
return; |
|
} |
|
|
|
if (!tc->td) |
|
DMEMIT("-"); |
|
else { |
|
switch (type) { |
|
case STATUSTYPE_INFO: |
|
r = dm_thin_get_mapped_count(tc->td, &mapped); |
|
if (r) { |
|
DMERR("dm_thin_get_mapped_count returned %d", r); |
|
goto err; |
|
} |
|
|
|
r = dm_thin_get_highest_mapped_block(tc->td, &highest); |
|
if (r < 0) { |
|
DMERR("dm_thin_get_highest_mapped_block returned %d", r); |
|
goto err; |
|
} |
|
|
|
DMEMIT("%llu ", mapped * tc->pool->sectors_per_block); |
|
if (r) |
|
DMEMIT("%llu", ((highest + 1) * |
|
tc->pool->sectors_per_block) - 1); |
|
else |
|
DMEMIT("-"); |
|
break; |
|
|
|
case STATUSTYPE_TABLE: |
|
DMEMIT("%s %lu", |
|
format_dev_t(buf, tc->pool_dev->bdev->bd_dev), |
|
(unsigned long) tc->dev_id); |
|
if (tc->origin_dev) |
|
DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev)); |
|
break; |
|
} |
|
} |
|
|
|
return; |
|
|
|
err: |
|
DMEMIT("Error"); |
|
} |
|
|
|
static int thin_iterate_devices(struct dm_target *ti, |
|
iterate_devices_callout_fn fn, void *data) |
|
{ |
|
sector_t blocks; |
|
struct thin_c *tc = ti->private; |
|
struct pool *pool = tc->pool; |
|
|
|
/* |
|
* We can't call dm_pool_get_data_dev_size() since that blocks. So |
|
* we follow a more convoluted path through to the pool's target. |
|
*/ |
|
if (!pool->ti) |
|
return 0; /* nothing is bound */ |
|
|
|
blocks = pool->ti->len; |
|
(void) sector_div(blocks, pool->sectors_per_block); |
|
if (blocks) |
|
return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data); |
|
|
|
return 0; |
|
} |
|
|
|
static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits) |
|
{ |
|
struct thin_c *tc = ti->private; |
|
struct pool *pool = tc->pool; |
|
|
|
if (!pool->pf.discard_enabled) |
|
return; |
|
|
|
limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT; |
|
limits->max_discard_sectors = 2048 * 1024 * 16; /* 16G */ |
|
} |
|
|
|
static struct target_type thin_target = { |
|
.name = "thin", |
|
.version = {1, 22, 0}, |
|
.module = THIS_MODULE, |
|
.ctr = thin_ctr, |
|
.dtr = thin_dtr, |
|
.map = thin_map, |
|
.end_io = thin_endio, |
|
.preresume = thin_preresume, |
|
.presuspend = thin_presuspend, |
|
.postsuspend = thin_postsuspend, |
|
.status = thin_status, |
|
.iterate_devices = thin_iterate_devices, |
|
.io_hints = thin_io_hints, |
|
}; |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static int __init dm_thin_init(void) |
|
{ |
|
int r = -ENOMEM; |
|
|
|
pool_table_init(); |
|
|
|
_new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0); |
|
if (!_new_mapping_cache) |
|
return r; |
|
|
|
r = dm_register_target(&thin_target); |
|
if (r) |
|
goto bad_new_mapping_cache; |
|
|
|
r = dm_register_target(&pool_target); |
|
if (r) |
|
goto bad_thin_target; |
|
|
|
return 0; |
|
|
|
bad_thin_target: |
|
dm_unregister_target(&thin_target); |
|
bad_new_mapping_cache: |
|
kmem_cache_destroy(_new_mapping_cache); |
|
|
|
return r; |
|
} |
|
|
|
static void dm_thin_exit(void) |
|
{ |
|
dm_unregister_target(&thin_target); |
|
dm_unregister_target(&pool_target); |
|
|
|
kmem_cache_destroy(_new_mapping_cache); |
|
|
|
pool_table_exit(); |
|
} |
|
|
|
module_init(dm_thin_init); |
|
module_exit(dm_thin_exit); |
|
|
|
module_param_named(no_space_timeout, no_space_timeout_secs, uint, S_IRUGO | S_IWUSR); |
|
MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds"); |
|
|
|
MODULE_DESCRIPTION(DM_NAME " thin provisioning target"); |
|
MODULE_AUTHOR("Joe Thornber <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|