mirror of https://gitee.com/openkylin/linux.git
3428 lines
84 KiB
C
3428 lines
84 KiB
C
/*
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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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#include "dm-thin-metadata.h"
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#include "dm-bio-prison.h"
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#include "dm.h"
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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/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/rbtree.h>
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#define DM_MSG_PREFIX "thin"
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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 PRISON_CELLS 1024
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#define COMMIT_PERIOD HZ
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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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* 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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* 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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* 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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* Key building.
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*/
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static void build_data_key(struct dm_thin_device *td,
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dm_block_t b, struct dm_cell_key *key)
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{
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key->virtual = 0;
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key->dev = dm_thin_dev_id(td);
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key->block = b;
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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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key->virtual = 1;
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key->dev = dm_thin_dev_id(td);
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key->block = b;
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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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* The pool runs in 4 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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PM_READ_ONLY, /* metadata may not be changed */
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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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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_mapping_fn)(struct dm_thin_new_mapping *m);
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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 *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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struct dm_bio_prison *prison;
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struct dm_kcopyd_client *copier;
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struct workqueue_struct *wq;
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struct work_struct worker;
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struct delayed_work waker;
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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 list_head prepared_mappings;
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struct list_head prepared_discards;
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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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mempool_t *mapping_pool;
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process_bio_fn process_bio;
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process_bio_fn process_discard;
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process_mapping_fn process_prepared_mapping;
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process_mapping_fn process_prepared_discard;
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};
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static enum pool_mode get_pool_mode(struct pool *pool);
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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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* 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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struct dm_target_callbacks callbacks;
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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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* 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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dm_thin_id dev_id;
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struct pool *pool;
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struct dm_thin_device *td;
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bool requeue_mode:1;
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spinlock_t lock;
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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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/*
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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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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_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_defer_no_holder_no_free(struct thin_c *tc,
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struct dm_bio_prison_cell *cell)
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{
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struct pool *pool = tc->pool;
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unsigned long flags;
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spin_lock_irqsave(&tc->lock, flags);
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dm_cell_release_no_holder(pool->prison, cell, &tc->deferred_bio_list);
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spin_unlock_irqrestore(&tc->lock, flags);
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wake_worker(pool);
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}
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static void cell_error(struct pool *pool,
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struct dm_bio_prison_cell *cell)
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{
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dm_cell_error(pool->prison, cell);
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dm_bio_prison_free_cell(pool->prison, cell);
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}
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/*----------------------------------------------------------------*/
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/*
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* A global list of pools that uses a struct mapped_device as a key.
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*/
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static struct dm_thin_pool_table {
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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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{
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mutex_init(&dm_thin_pool_table.mutex);
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INIT_LIST_HEAD(&dm_thin_pool_table.pools);
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}
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static void __pool_table_insert(struct pool *pool)
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{
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BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
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list_add(&pool->list, &dm_thin_pool_table.pools);
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}
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static void __pool_table_remove(struct pool *pool)
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{
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BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
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list_del(&pool->list);
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}
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static struct pool *__pool_table_lookup(struct mapped_device *md)
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{
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struct pool *pool = NULL, *tmp;
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BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
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list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
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if (tmp->pool_md == md) {
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pool = tmp;
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break;
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}
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}
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return pool;
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}
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static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
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{
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struct pool *pool = NULL, *tmp;
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BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
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list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
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if (tmp->md_dev == md_dev) {
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pool = tmp;
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break;
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}
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}
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return pool;
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}
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/*----------------------------------------------------------------*/
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struct dm_thin_endio_hook {
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struct thin_c *tc;
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struct dm_deferred_entry *shared_read_entry;
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struct dm_deferred_entry *all_io_entry;
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struct dm_thin_new_mapping *overwrite_mapping;
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struct rb_node rb_node;
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};
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static void requeue_bio_list(struct thin_c *tc, struct bio_list *master)
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{
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struct bio *bio;
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struct bio_list bios;
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unsigned long flags;
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bio_list_init(&bios);
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spin_lock_irqsave(&tc->lock, flags);
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bio_list_merge(&bios, master);
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bio_list_init(master);
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spin_unlock_irqrestore(&tc->lock, flags);
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while ((bio = bio_list_pop(&bios)))
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bio_endio(bio, DM_ENDIO_REQUEUE);
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}
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static void requeue_io(struct thin_c *tc)
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{
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requeue_bio_list(tc, &tc->deferred_bio_list);
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requeue_bio_list(tc, &tc->retry_on_resume_list);
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}
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static void error_thin_retry_list(struct thin_c *tc)
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{
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struct bio *bio;
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unsigned long flags;
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struct bio_list bios;
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bio_list_init(&bios);
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spin_lock_irqsave(&tc->lock, flags);
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bio_list_merge(&bios, &tc->retry_on_resume_list);
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bio_list_init(&tc->retry_on_resume_list);
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spin_unlock_irqrestore(&tc->lock, flags);
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while ((bio = bio_list_pop(&bios)))
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bio_io_error(bio);
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}
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static void error_retry_list(struct pool *pool)
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{
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struct thin_c *tc;
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rcu_read_lock();
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list_for_each_entry_rcu(tc, &pool->active_thins, list)
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error_thin_retry_list(tc);
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rcu_read_unlock();
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}
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/*
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* This section of code contains the logic for processing a thin device's IO.
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* Much of the code depends on pool object resources (lists, workqueues, etc)
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* but most is exclusively called from the thin target rather than the thin-pool
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* target.
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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 dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
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{
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struct pool *pool = tc->pool;
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sector_t block_nr = bio->bi_iter.bi_sector;
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if (block_size_is_power_of_two(pool))
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block_nr >>= pool->sectors_per_block_shift;
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else
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(void) sector_div(block_nr, pool->sectors_per_block);
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return block_nr;
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}
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static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
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{
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struct pool *pool = tc->pool;
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sector_t bi_sector = bio->bi_iter.bi_sector;
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bio->bi_bdev = tc->pool_dev->bdev;
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if (block_size_is_power_of_two(pool))
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bio->bi_iter.bi_sector =
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(block << pool->sectors_per_block_shift) |
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(bi_sector & (pool->sectors_per_block - 1));
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else
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bio->bi_iter.bi_sector = (block * pool->sectors_per_block) +
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sector_div(bi_sector, pool->sectors_per_block);
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}
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static void remap_to_origin(struct thin_c *tc, struct bio *bio)
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{
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bio->bi_bdev = tc->origin_dev->bdev;
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}
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static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
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{
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return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) &&
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dm_thin_changed_this_transaction(tc->td);
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}
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static void inc_all_io_entry(struct pool *pool, struct bio *bio)
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{
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struct dm_thin_endio_hook *h;
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if (bio->bi_rw & REQ_DISCARD)
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return;
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h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
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h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
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}
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static void issue(struct thin_c *tc, struct bio *bio)
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{
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struct pool *pool = tc->pool;
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unsigned long flags;
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if (!bio_triggers_commit(tc, bio)) {
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generic_make_request(bio);
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return;
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}
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/*
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* Complete bio with an error if earlier I/O caused changes to
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* the metadata that can't be committed e.g, due to I/O errors
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* on the metadata device.
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*/
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if (dm_thin_aborted_changes(tc->td)) {
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bio_io_error(bio);
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return;
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}
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/*
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* Batch together any bios that trigger commits and then issue a
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* single commit for them in process_deferred_bios().
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*/
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spin_lock_irqsave(&pool->lock, flags);
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bio_list_add(&pool->deferred_flush_bios, bio);
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spin_unlock_irqrestore(&pool->lock, flags);
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}
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static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
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{
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remap_to_origin(tc, bio);
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issue(tc, bio);
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}
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static void remap_and_issue(struct thin_c *tc, struct bio *bio,
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dm_block_t block)
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{
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remap(tc, bio, block);
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issue(tc, bio);
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* Bio endio functions.
|
|
*/
|
|
struct dm_thin_new_mapping {
|
|
struct list_head list;
|
|
|
|
bool quiesced:1;
|
|
bool prepared:1;
|
|
bool pass_discard:1;
|
|
bool definitely_not_shared:1;
|
|
|
|
int err;
|
|
struct thin_c *tc;
|
|
dm_block_t virt_block;
|
|
dm_block_t data_block;
|
|
struct dm_bio_prison_cell *cell, *cell2;
|
|
|
|
/*
|
|
* 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 __maybe_add_mapping(struct dm_thin_new_mapping *m)
|
|
{
|
|
struct pool *pool = m->tc->pool;
|
|
|
|
if (m->quiesced && m->prepared) {
|
|
list_add_tail(&m->list, &pool->prepared_mappings);
|
|
wake_worker(pool);
|
|
}
|
|
}
|
|
|
|
static void copy_complete(int read_err, unsigned long write_err, void *context)
|
|
{
|
|
unsigned long flags;
|
|
struct dm_thin_new_mapping *m = context;
|
|
struct pool *pool = m->tc->pool;
|
|
|
|
m->err = read_err || write_err ? -EIO : 0;
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
m->prepared = true;
|
|
__maybe_add_mapping(m);
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
}
|
|
|
|
static void overwrite_endio(struct bio *bio, int err)
|
|
{
|
|
unsigned long flags;
|
|
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;
|
|
struct pool *pool = m->tc->pool;
|
|
|
|
m->err = err;
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
m->prepared = true;
|
|
__maybe_add_mapping(m);
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* Workqueue.
|
|
*/
|
|
|
|
/*
|
|
* Prepared mapping jobs.
|
|
*/
|
|
|
|
/*
|
|
* This sends the bios in the cell back to the deferred_bios list.
|
|
*/
|
|
static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell)
|
|
{
|
|
struct pool *pool = tc->pool;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
cell_release(pool, cell, &tc->deferred_bio_list);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
|
|
wake_worker(pool);
|
|
}
|
|
|
|
/*
|
|
* Same as cell_defer above, except it omits the original holder of the cell.
|
|
*/
|
|
static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
|
|
{
|
|
struct pool *pool = tc->pool;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
cell_release_no_holder(pool, cell, &tc->deferred_bio_list);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
|
|
wake_worker(pool);
|
|
}
|
|
|
|
static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
|
|
{
|
|
if (m->bio) {
|
|
m->bio->bi_end_io = m->saved_bi_end_io;
|
|
atomic_inc(&m->bio->bi_remaining);
|
|
}
|
|
cell_error(m->tc->pool, m->cell);
|
|
list_del(&m->list);
|
|
mempool_free(m, m->tc->pool->mapping_pool);
|
|
}
|
|
|
|
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;
|
|
int r;
|
|
|
|
bio = m->bio;
|
|
if (bio) {
|
|
bio->bi_end_io = m->saved_bi_end_io;
|
|
atomic_inc(&bio->bi_remaining);
|
|
}
|
|
|
|
if (m->err) {
|
|
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_block, 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) {
|
|
cell_defer_no_holder(tc, m->cell);
|
|
bio_endio(bio, 0);
|
|
} else
|
|
cell_defer(tc, m->cell);
|
|
|
|
out:
|
|
list_del(&m->list);
|
|
mempool_free(m, pool->mapping_pool);
|
|
}
|
|
|
|
static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
|
|
{
|
|
struct thin_c *tc = m->tc;
|
|
|
|
bio_io_error(m->bio);
|
|
cell_defer_no_holder(tc, m->cell);
|
|
cell_defer_no_holder(tc, m->cell2);
|
|
mempool_free(m, tc->pool->mapping_pool);
|
|
}
|
|
|
|
static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
|
|
{
|
|
struct thin_c *tc = m->tc;
|
|
|
|
inc_all_io_entry(tc->pool, m->bio);
|
|
cell_defer_no_holder(tc, m->cell);
|
|
cell_defer_no_holder(tc, m->cell2);
|
|
|
|
if (m->pass_discard)
|
|
if (m->definitely_not_shared)
|
|
remap_and_issue(tc, m->bio, m->data_block);
|
|
else {
|
|
bool used = false;
|
|
if (dm_pool_block_is_used(tc->pool->pmd, m->data_block, &used) || used)
|
|
bio_endio(m->bio, 0);
|
|
else
|
|
remap_and_issue(tc, m->bio, m->data_block);
|
|
}
|
|
else
|
|
bio_endio(m->bio, 0);
|
|
|
|
mempool_free(m, tc->pool->mapping_pool);
|
|
}
|
|
|
|
static void process_prepared_discard(struct dm_thin_new_mapping *m)
|
|
{
|
|
int r;
|
|
struct thin_c *tc = m->tc;
|
|
|
|
r = dm_thin_remove_block(tc->td, m->virt_block);
|
|
if (r)
|
|
DMERR_LIMIT("dm_thin_remove_block() failed");
|
|
|
|
process_prepared_discard_passdown(m);
|
|
}
|
|
|
|
static void process_prepared(struct pool *pool, struct list_head *head,
|
|
process_mapping_fn *fn)
|
|
{
|
|
unsigned long flags;
|
|
struct list_head maps;
|
|
struct dm_thin_new_mapping *m, *tmp;
|
|
|
|
INIT_LIST_HEAD(&maps);
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
list_splice_init(head, &maps);
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
|
|
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 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)
|
|
{
|
|
int r;
|
|
struct pool *pool = tc->pool;
|
|
struct dm_thin_new_mapping *m = get_next_mapping(pool);
|
|
|
|
m->tc = tc;
|
|
m->virt_block = virt_block;
|
|
m->data_block = data_dest;
|
|
m->cell = cell;
|
|
|
|
if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
|
|
m->quiesced = true;
|
|
|
|
/*
|
|
* 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)) {
|
|
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_dest);
|
|
} else {
|
|
struct dm_io_region from, to;
|
|
|
|
from.bdev = origin->bdev;
|
|
from.sector = data_origin * pool->sectors_per_block;
|
|
from.count = pool->sectors_per_block;
|
|
|
|
to.bdev = tc->pool_dev->bdev;
|
|
to.sector = data_dest * pool->sectors_per_block;
|
|
to.count = pool->sectors_per_block;
|
|
|
|
r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
|
|
0, copy_complete, m);
|
|
if (r < 0) {
|
|
mempool_free(m, pool->mapping_pool);
|
|
DMERR_LIMIT("dm_kcopyd_copy() failed");
|
|
cell_error(pool, cell);
|
|
}
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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)
|
|
{
|
|
schedule_copy(tc, virt_block, tc->origin_dev,
|
|
virt_block, data_dest, cell, bio);
|
|
}
|
|
|
|
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);
|
|
|
|
m->quiesced = true;
|
|
m->prepared = false;
|
|
m->tc = tc;
|
|
m->virt_block = virt_block;
|
|
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)
|
|
process_prepared_mapping(m);
|
|
|
|
else if (io_overwrites_block(pool, bio)) {
|
|
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_block);
|
|
} else {
|
|
int r;
|
|
struct dm_io_region to;
|
|
|
|
to.bdev = tc->pool_dev->bdev;
|
|
to.sector = data_block * pool->sectors_per_block;
|
|
to.count = pool->sectors_per_block;
|
|
|
|
r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
|
|
if (r < 0) {
|
|
mempool_free(m, pool->mapping_pool);
|
|
DMERR_LIMIT("dm_kcopyd_zero() failed");
|
|
cell_error(pool, cell);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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_WRITE)
|
|
return -EINVAL;
|
|
|
|
r = dm_pool_commit_metadata(pool->pmd);
|
|
if (r)
|
|
metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks)
|
|
{
|
|
unsigned long flags;
|
|
|
|
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_irqsave(&pool->lock, flags);
|
|
pool->low_water_triggered = true;
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
dm_table_event(pool->ti->table);
|
|
}
|
|
}
|
|
|
|
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
|
|
|
|
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) {
|
|
metadata_operation_failed(pool, "dm_pool_alloc_data_block", 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;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
bio_list_add(&tc->retry_on_resume_list, bio);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
}
|
|
|
|
static bool 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 true;
|
|
|
|
case PM_OUT_OF_DATA_SPACE:
|
|
return pool->pf.error_if_no_space;
|
|
|
|
case PM_READ_ONLY:
|
|
case PM_FAIL:
|
|
return true;
|
|
default:
|
|
/* Shouldn't get here */
|
|
DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static void handle_unserviceable_bio(struct pool *pool, struct bio *bio)
|
|
{
|
|
if (should_error_unserviceable_bio(pool))
|
|
bio_io_error(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;
|
|
|
|
if (should_error_unserviceable_bio(pool)) {
|
|
cell_error(pool, cell);
|
|
return;
|
|
}
|
|
|
|
bio_list_init(&bios);
|
|
cell_release(pool, cell, &bios);
|
|
|
|
if (should_error_unserviceable_bio(pool))
|
|
while ((bio = bio_list_pop(&bios)))
|
|
bio_io_error(bio);
|
|
else
|
|
while ((bio = bio_list_pop(&bios)))
|
|
retry_on_resume(bio);
|
|
}
|
|
|
|
static void process_discard(struct thin_c *tc, struct bio *bio)
|
|
{
|
|
int r;
|
|
unsigned long flags;
|
|
struct pool *pool = tc->pool;
|
|
struct dm_bio_prison_cell *cell, *cell2;
|
|
struct dm_cell_key key, key2;
|
|
dm_block_t block = get_bio_block(tc, bio);
|
|
struct dm_thin_lookup_result lookup_result;
|
|
struct dm_thin_new_mapping *m;
|
|
|
|
build_virtual_key(tc->td, block, &key);
|
|
if (bio_detain(tc->pool, &key, bio, &cell))
|
|
return;
|
|
|
|
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
|
|
switch (r) {
|
|
case 0:
|
|
/*
|
|
* Check nobody is fiddling with this pool block. This can
|
|
* happen if someone's in the process of breaking sharing
|
|
* on this block.
|
|
*/
|
|
build_data_key(tc->td, lookup_result.block, &key2);
|
|
if (bio_detain(tc->pool, &key2, bio, &cell2)) {
|
|
cell_defer_no_holder(tc, cell);
|
|
break;
|
|
}
|
|
|
|
if (io_overlaps_block(pool, bio)) {
|
|
/*
|
|
* 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->pass_discard = pool->pf.discard_passdown;
|
|
m->definitely_not_shared = !lookup_result.shared;
|
|
m->virt_block = block;
|
|
m->data_block = lookup_result.block;
|
|
m->cell = cell;
|
|
m->cell2 = cell2;
|
|
m->bio = bio;
|
|
|
|
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
list_add_tail(&m->list, &pool->prepared_discards);
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
wake_worker(pool);
|
|
}
|
|
} else {
|
|
inc_all_io_entry(pool, bio);
|
|
cell_defer_no_holder(tc, cell);
|
|
cell_defer_no_holder(tc, cell2);
|
|
|
|
/*
|
|
* The DM core makes sure that the discard doesn't span
|
|
* a block boundary. So we submit the discard of a
|
|
* partial block appropriately.
|
|
*/
|
|
if ((!lookup_result.shared) && pool->pf.discard_passdown)
|
|
remap_and_issue(tc, bio, lookup_result.block);
|
|
else
|
|
bio_endio(bio, 0);
|
|
}
|
|
break;
|
|
|
|
case -ENODATA:
|
|
/*
|
|
* It isn't provisioned, just forget it.
|
|
*/
|
|
cell_defer_no_holder(tc, cell);
|
|
bio_endio(bio, 0);
|
|
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 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 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 *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, &cell))
|
|
return;
|
|
|
|
if (bio_data_dir(bio) == WRITE && bio->bi_iter.bi_size)
|
|
break_sharing(tc, bio, block, &key, lookup_result, 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);
|
|
cell_defer_no_holder(tc, cell);
|
|
|
|
remap_and_issue(tc, bio, 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, 0);
|
|
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_bio(struct thin_c *tc, struct bio *bio)
|
|
{
|
|
int r;
|
|
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;
|
|
struct dm_thin_lookup_result lookup_result;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
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_defer_no_holder(tc, cell); /* FIXME: pass this cell into process_shared? */
|
|
} else {
|
|
inc_all_io_entry(pool, bio);
|
|
cell_defer_no_holder(tc, cell);
|
|
|
|
remap_and_issue(tc, bio, 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);
|
|
|
|
remap_to_origin_and_issue(tc, 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_read_only(struct thin_c *tc, struct bio *bio)
|
|
{
|
|
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);
|
|
else {
|
|
inc_all_io_entry(tc->pool, bio);
|
|
remap_and_issue(tc, bio, lookup_result.block);
|
|
}
|
|
break;
|
|
|
|
case -ENODATA:
|
|
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, 0);
|
|
break;
|
|
|
|
default:
|
|
DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
|
|
__func__, r);
|
|
bio_io_error(bio);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void process_bio_success(struct thin_c *tc, struct bio *bio)
|
|
{
|
|
bio_endio(bio, 0);
|
|
}
|
|
|
|
static void process_bio_fail(struct thin_c *tc, struct bio *bio)
|
|
{
|
|
bio_io_error(bio);
|
|
}
|
|
|
|
/*
|
|
* 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 jiffies < pool->last_commit_jiffies ||
|
|
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;
|
|
unsigned long flags;
|
|
struct bio *bio;
|
|
struct bio_list bios;
|
|
struct blk_plug plug;
|
|
|
|
if (tc->requeue_mode) {
|
|
requeue_bio_list(tc, &tc->deferred_bio_list);
|
|
return;
|
|
}
|
|
|
|
bio_list_init(&bios);
|
|
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
|
|
if (bio_list_empty(&tc->deferred_bio_list)) {
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
return;
|
|
}
|
|
|
|
__sort_thin_deferred_bios(tc);
|
|
|
|
bio_list_merge(&bios, &tc->deferred_bio_list);
|
|
bio_list_init(&tc->deferred_bio_list);
|
|
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
|
|
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_irqsave(&tc->lock, flags);
|
|
bio_list_add(&tc->deferred_bio_list, bio);
|
|
bio_list_merge(&tc->deferred_bio_list, &bios);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
break;
|
|
}
|
|
|
|
if (bio->bi_rw & REQ_DISCARD)
|
|
pool->process_discard(tc, bio);
|
|
else
|
|
pool->process_bio(tc, bio);
|
|
}
|
|
blk_finish_plug(&plug);
|
|
}
|
|
|
|
static void process_deferred_bios(struct pool *pool)
|
|
{
|
|
unsigned long flags;
|
|
struct bio *bio;
|
|
struct bio_list bios;
|
|
struct thin_c *tc;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(tc, &pool->active_thins, list)
|
|
process_thin_deferred_bios(tc);
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* If there are any deferred flush bios, we must commit
|
|
* the metadata before issuing them.
|
|
*/
|
|
bio_list_init(&bios);
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
bio_list_merge(&bios, &pool->deferred_flush_bios);
|
|
bio_list_init(&pool->deferred_flush_bios);
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
|
|
if (bio_list_empty(&bios) &&
|
|
!(dm_pool_changed_this_transaction(pool->pmd) && need_commit_due_to_time(pool)))
|
|
return;
|
|
|
|
if (commit(pool)) {
|
|
while ((bio = bio_list_pop(&bios)))
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
pool->last_commit_jiffies = jiffies;
|
|
|
|
while ((bio = bio_list_pop(&bios)))
|
|
generic_make_request(bio);
|
|
}
|
|
|
|
static void do_worker(struct work_struct *ws)
|
|
{
|
|
struct pool *pool = container_of(ws, struct pool, worker);
|
|
|
|
process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
|
|
process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
|
|
process_deferred_bios(pool);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
struct noflush_work {
|
|
struct work_struct worker;
|
|
struct thin_c *tc;
|
|
|
|
atomic_t complete;
|
|
wait_queue_head_t wait;
|
|
};
|
|
|
|
static void complete_noflush_work(struct noflush_work *w)
|
|
{
|
|
atomic_set(&w->complete, 1);
|
|
wake_up(&w->wait);
|
|
}
|
|
|
|
static void do_noflush_start(struct work_struct *ws)
|
|
{
|
|
struct noflush_work *w = container_of(ws, struct noflush_work, worker);
|
|
w->tc->requeue_mode = true;
|
|
requeue_io(w->tc);
|
|
complete_noflush_work(w);
|
|
}
|
|
|
|
static void do_noflush_stop(struct work_struct *ws)
|
|
{
|
|
struct noflush_work *w = container_of(ws, struct noflush_work, worker);
|
|
w->tc->requeue_mode = false;
|
|
complete_noflush_work(w);
|
|
}
|
|
|
|
static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *))
|
|
{
|
|
struct noflush_work w;
|
|
|
|
INIT_WORK(&w.worker, fn);
|
|
w.tc = tc;
|
|
atomic_set(&w.complete, 0);
|
|
init_waitqueue_head(&w.wait);
|
|
|
|
queue_work(tc->pool->wq, &w.worker);
|
|
|
|
wait_event(w.wait, atomic_read(&w.complete));
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
static enum pool_mode get_pool_mode(struct pool *pool)
|
|
{
|
|
return pool->pf.mode;
|
|
}
|
|
|
|
static void notify_of_pool_mode_change(struct pool *pool, const char *new_mode)
|
|
{
|
|
dm_table_event(pool->ti->table);
|
|
DMINFO("%s: switching pool to %s mode",
|
|
dm_device_name(pool->pool_md), new_mode);
|
|
}
|
|
|
|
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);
|
|
|
|
/*
|
|
* 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:
|
|
if (old_mode != new_mode)
|
|
notify_of_pool_mode_change(pool, "failure");
|
|
dm_pool_metadata_read_only(pool->pmd);
|
|
pool->process_bio = process_bio_fail;
|
|
pool->process_discard = process_bio_fail;
|
|
pool->process_prepared_mapping = process_prepared_mapping_fail;
|
|
pool->process_prepared_discard = process_prepared_discard_fail;
|
|
|
|
error_retry_list(pool);
|
|
break;
|
|
|
|
case PM_READ_ONLY:
|
|
if (old_mode != new_mode)
|
|
notify_of_pool_mode_change(pool, "read-only");
|
|
dm_pool_metadata_read_only(pool->pmd);
|
|
pool->process_bio = process_bio_read_only;
|
|
pool->process_discard = process_bio_success;
|
|
pool->process_prepared_mapping = process_prepared_mapping_fail;
|
|
pool->process_prepared_discard = process_prepared_discard_passdown;
|
|
|
|
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.
|
|
*/
|
|
if (old_mode != new_mode)
|
|
notify_of_pool_mode_change(pool, "out-of-data-space");
|
|
pool->process_bio = process_bio_read_only;
|
|
pool->process_discard = process_discard;
|
|
pool->process_prepared_mapping = process_prepared_mapping;
|
|
pool->process_prepared_discard = process_prepared_discard_passdown;
|
|
break;
|
|
|
|
case PM_WRITE:
|
|
if (old_mode != new_mode)
|
|
notify_of_pool_mode_change(pool, "write");
|
|
dm_pool_metadata_read_write(pool->pmd);
|
|
pool->process_bio = process_bio;
|
|
pool->process_discard = process_discard;
|
|
pool->process_prepared_mapping = process_prepared_mapping;
|
|
pool->process_prepared_discard = process_prepared_discard;
|
|
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;
|
|
}
|
|
|
|
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)
|
|
{
|
|
unsigned long flags;
|
|
struct pool *pool = tc->pool;
|
|
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
bio_list_add(&tc->deferred_bio_list, bio);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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 cell1, cell2;
|
|
struct dm_bio_prison_cell *cell_result;
|
|
struct dm_cell_key key;
|
|
|
|
thin_hook_bio(tc, bio);
|
|
|
|
if (tc->requeue_mode) {
|
|
bio_endio(bio, DM_ENDIO_REQUEUE);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
if (get_pool_mode(tc->pool) == PM_FAIL) {
|
|
bio_io_error(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) {
|
|
thin_defer_bio(tc, bio);
|
|
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_bio(tc, bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
build_virtual_key(tc->td, block, &key);
|
|
if (dm_bio_detain(tc->pool->prison, &key, bio, &cell1, &cell_result))
|
|
return DM_MAPIO_SUBMITTED;
|
|
|
|
build_data_key(tc->td, result.block, &key);
|
|
if (dm_bio_detain(tc->pool->prison, &key, bio, &cell2, &cell_result)) {
|
|
cell_defer_no_holder_no_free(tc, &cell1);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
inc_all_io_entry(tc->pool, bio);
|
|
cell_defer_no_holder_no_free(tc, &cell2);
|
|
cell_defer_no_holder_no_free(tc, &cell1);
|
|
|
|
remap(tc, bio, result.block);
|
|
return DM_MAPIO_REMAPPED;
|
|
|
|
case -ENODATA:
|
|
if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
|
|
/*
|
|
* This block isn't provisioned, and we have no way
|
|
* of doing so.
|
|
*/
|
|
handle_unserviceable_bio(tc->pool, bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
/* fall through */
|
|
|
|
case -EWOULDBLOCK:
|
|
/*
|
|
* In future, the failed dm_thin_find_block above could
|
|
* provide the hint to load the metadata into cache.
|
|
*/
|
|
thin_defer_bio(tc, bio);
|
|
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);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
}
|
|
|
|
static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
|
|
{
|
|
struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
|
|
struct request_queue *q;
|
|
|
|
if (get_pool_mode(pt->pool) == PM_OUT_OF_DATA_SPACE)
|
|
return 1;
|
|
|
|
q = bdev_get_queue(pt->data_dev->bdev);
|
|
return bdi_congested(&q->backing_dev_info, bdi_bits);
|
|
}
|
|
|
|
static void requeue_bios(struct pool *pool)
|
|
{
|
|
unsigned long flags;
|
|
struct thin_c *tc;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(tc, &pool->active_thins, list) {
|
|
spin_lock_irqsave(&tc->lock, flags);
|
|
bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list);
|
|
bio_list_init(&tc->retry_on_resume_list);
|
|
spin_unlock_irqrestore(&tc->lock, flags);
|
|
}
|
|
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 q && 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;
|
|
sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
|
|
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";
|
|
|
|
else if (data_limits->discard_granularity > block_size)
|
|
reason = "discard granularity larger than a block";
|
|
|
|
else if (!is_factor(block_size, data_limits->discard_granularity))
|
|
reason = "discard granularity not a factor of block size";
|
|
|
|
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);
|
|
|
|
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_destroy(pool->mapping_pool);
|
|
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,
|
|
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 = kmalloc(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(PRISON_CELLS);
|
|
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;
|
|
}
|
|
|
|
INIT_WORK(&pool->worker, do_worker);
|
|
INIT_DELAYED_WORK(&pool->waker, do_waker);
|
|
spin_lock_init(&pool->lock);
|
|
bio_list_init(&pool->deferred_flush_bios);
|
|
INIT_LIST_HEAD(&pool->prepared_mappings);
|
|
INIT_LIST_HEAD(&pool->prepared_discards);
|
|
INIT_LIST_HEAD(&pool->active_thins);
|
|
pool->low_water_triggered = false;
|
|
|
|
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;
|
|
pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
|
|
_new_mapping_cache);
|
|
if (!pool->mapping_pool) {
|
|
*error = "Error creating pool's mapping mempool";
|
|
err_p = ERR_PTR(-ENOMEM);
|
|
goto bad_mapping_pool;
|
|
}
|
|
|
|
pool->ref_count = 1;
|
|
pool->last_commit_jiffies = jiffies;
|
|
pool->pool_md = pool_md;
|
|
pool->md_dev = metadata_dev;
|
|
__pool_table_insert(pool);
|
|
|
|
return 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,
|
|
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);
|
|
}
|
|
__pool_inc(pool);
|
|
|
|
} else {
|
|
pool = __pool_table_lookup(pool_md);
|
|
if (pool) {
|
|
if (pool->md_dev != metadata_dev) {
|
|
*error = "different pool cannot replace a pool";
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
__pool_inc(pool);
|
|
|
|
} else {
|
|
pool = pool_create(pool_md, metadata_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 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);
|
|
}
|
|
|
|
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;
|
|
|
|
/*
|
|
* 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,
|
|
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.
|
|
*/
|
|
ti->discard_zeroes_data_unsupported = true;
|
|
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_free_pt;
|
|
|
|
pt->callbacks.congested_fn = pool_is_congested;
|
|
dm_table_add_target_callbacks(ti->table, &pt->callbacks);
|
|
|
|
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;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* As this is a singleton target, ti->begin is always zero.
|
|
*/
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
bio->bi_bdev = pt->data_dev->bdev;
|
|
r = DM_MAPIO_REMAPPED;
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
|
|
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);
|
|
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_resume(struct dm_target *ti)
|
|
{
|
|
struct pool_c *pt = ti->private;
|
|
struct pool *pool = pt->pool;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
pool->low_water_triggered = false;
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
requeue_bios(pool);
|
|
|
|
do_waker(&pool->waker.work);
|
|
}
|
|
|
|
static void pool_postsuspend(struct dm_target *ti)
|
|
{
|
|
struct pool_c *pt = ti->private;
|
|
struct pool *pool = pt->pool;
|
|
|
|
cancel_delayed_work(&pool->waker);
|
|
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>
|
|
* trim <dev_id> <new_size_in_sectors>
|
|
* 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)
|
|
{
|
|
int r = -EINVAL;
|
|
struct pool_c *pt = ti->private;
|
|
struct pool *pool = pt->pool;
|
|
|
|
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>
|
|
*/
|
|
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;
|
|
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("- ");
|
|
|
|
if (pool->pf.mode == PM_OUT_OF_DATA_SPACE)
|
|
DMEMIT("out_of_data_space ");
|
|
else if (pool->pf.mode == PM_READ_ONLY)
|
|
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 ");
|
|
|
|
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 int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
|
|
struct bio_vec *biovec, int max_size)
|
|
{
|
|
struct pool_c *pt = ti->private;
|
|
struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
|
|
|
|
if (!q->merge_bvec_fn)
|
|
return max_size;
|
|
|
|
bvm->bi_bdev = pt->data_dev->bdev;
|
|
|
|
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
|
|
}
|
|
|
|
static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
|
|
{
|
|
struct pool *pool = pt->pool;
|
|
struct queue_limits *data_limits;
|
|
|
|
limits->max_discard_sectors = pool->sectors_per_block;
|
|
|
|
/*
|
|
* discard_granularity is just a hint, and not enforced.
|
|
*/
|
|
if (pt->adjusted_pf.discard_passdown) {
|
|
data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
|
|
limits->discard_granularity = data_limits->discard_granularity;
|
|
} else
|
|
limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
|
|
}
|
|
|
|
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
|
|
{
|
|
struct pool_c *pt = ti->private;
|
|
struct pool *pool = pt->pool;
|
|
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
|
|
|
|
/*
|
|
* 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 ||
|
|
do_div(io_opt_sectors, pool->sectors_per_block)) {
|
|
blk_limits_io_min(limits, 0);
|
|
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);
|
|
|
|
set_discard_limits(pt, limits);
|
|
}
|
|
|
|
static struct target_type pool_target = {
|
|
.name = "thin-pool",
|
|
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
|
|
DM_TARGET_IMMUTABLE,
|
|
.version = {1, 12, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = pool_ctr,
|
|
.dtr = pool_dtr,
|
|
.map = pool_map,
|
|
.postsuspend = pool_postsuspend,
|
|
.preresume = pool_preresume,
|
|
.resume = pool_resume,
|
|
.message = pool_message,
|
|
.status = pool_status,
|
|
.merge = pool_merge,
|
|
.iterate_devices = pool_iterate_devices,
|
|
.io_hints = pool_io_hints,
|
|
};
|
|
|
|
/*----------------------------------------------------------------
|
|
* Thin target methods
|
|
*--------------------------------------------------------------*/
|
|
static void thin_dtr(struct dm_target *ti)
|
|
{
|
|
struct thin_c *tc = ti->private;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&tc->pool->lock, flags);
|
|
list_del_rcu(&tc->list);
|
|
spin_unlock_irqrestore(&tc->pool->lock, flags);
|
|
synchronize_rcu();
|
|
|
|
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;
|
|
}
|
|
spin_lock_init(&tc->lock);
|
|
bio_list_init(&tc->deferred_bio_list);
|
|
bio_list_init(&tc->retry_on_resume_list);
|
|
tc->sort_bio_list = RB_ROOT;
|
|
|
|
if (argc == 3) {
|
|
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_thin_open;
|
|
}
|
|
|
|
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_thin_open;
|
|
}
|
|
|
|
r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
|
|
if (r)
|
|
goto bad_target_max_io_len;
|
|
|
|
ti->num_flush_bios = 1;
|
|
ti->flush_supported = true;
|
|
ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook);
|
|
|
|
/* In case the pool supports discards, pass them on. */
|
|
ti->discard_zeroes_data_unsupported = true;
|
|
if (tc->pool->pf.discard_enabled) {
|
|
ti->discards_supported = true;
|
|
ti->num_discard_bios = 1;
|
|
/* Discard bios must be split on a block boundary */
|
|
ti->split_discard_bios = true;
|
|
}
|
|
|
|
dm_put(pool_md);
|
|
|
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
|
|
|
spin_lock(&tc->pool->lock);
|
|
list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
|
|
spin_unlock(&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();
|
|
|
|
return 0;
|
|
|
|
bad_target_max_io_len:
|
|
dm_pool_close_thin_device(tc->td);
|
|
bad_thin_open:
|
|
__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, int 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);
|
|
m->quiesced = true;
|
|
__maybe_add_mapping(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);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* <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 struct target_type thin_target = {
|
|
.name = "thin",
|
|
.version = {1, 12, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = thin_ctr,
|
|
.dtr = thin_dtr,
|
|
.map = thin_map,
|
|
.end_io = thin_endio,
|
|
.presuspend = thin_presuspend,
|
|
.postsuspend = thin_postsuspend,
|
|
.status = thin_status,
|
|
.iterate_devices = thin_iterate_devices,
|
|
};
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
static int __init dm_thin_init(void)
|
|
{
|
|
int r;
|
|
|
|
pool_table_init();
|
|
|
|
r = dm_register_target(&thin_target);
|
|
if (r)
|
|
return r;
|
|
|
|
r = dm_register_target(&pool_target);
|
|
if (r)
|
|
goto bad_pool_target;
|
|
|
|
r = -ENOMEM;
|
|
|
|
_new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
|
|
if (!_new_mapping_cache)
|
|
goto bad_new_mapping_cache;
|
|
|
|
return 0;
|
|
|
|
bad_new_mapping_cache:
|
|
dm_unregister_target(&pool_target);
|
|
bad_pool_target:
|
|
dm_unregister_target(&thin_target);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void dm_thin_exit(void)
|
|
{
|
|
dm_unregister_target(&thin_target);
|
|
dm_unregister_target(&pool_target);
|
|
|
|
kmem_cache_destroy(_new_mapping_cache);
|
|
}
|
|
|
|
module_init(dm_thin_init);
|
|
module_exit(dm_thin_exit);
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
|
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|