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-rw-r--r--ANDROID_3.4.5/drivers/md/dm-thin.c2774
1 files changed, 0 insertions, 2774 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-thin.c b/ANDROID_3.4.5/drivers/md/dm-thin.c
deleted file mode 100644
index eb3d138f..00000000
--- a/ANDROID_3.4.5/drivers/md/dm-thin.c
+++ /dev/null
@@ -1,2774 +0,0 @@
-/*
- * Copyright (C) 2011 Red Hat UK.
- *
- * This file is released under the GPL.
- */
-
-#include "dm-thin-metadata.h"
-
-#include <linux/device-mapper.h>
-#include <linux/dm-io.h>
-#include <linux/dm-kcopyd.h>
-#include <linux/list.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-
-#define DM_MSG_PREFIX "thin"
-
-/*
- * Tunable constants
- */
-#define ENDIO_HOOK_POOL_SIZE 10240
-#define DEFERRED_SET_SIZE 64
-#define MAPPING_POOL_SIZE 1024
-#define PRISON_CELLS 1024
-#define COMMIT_PERIOD HZ
-
-/*
- * The block size of the device holding pool data must be
- * between 64KB and 1GB.
- */
-#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
-#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
-
-/*
- * Device id is restricted to 24 bits.
- */
-#define MAX_DEV_ID ((1 << 24) - 1)
-
-/*
- * How do we handle breaking sharing of data blocks?
- * =================================================
- *
- * We use a standard copy-on-write btree to store the mappings for the
- * devices (note I'm talking about copy-on-write of the metadata here, not
- * the data). When you take an internal snapshot you clone the root node
- * of the origin btree. After this there is no concept of an origin or a
- * snapshot. They are just two device trees that happen to point to the
- * same data blocks.
- *
- * When we get a write in we decide if it's to a shared data block using
- * some timestamp magic. If it is, we have to break sharing.
- *
- * Let's say we write to a shared block in what was the origin. The
- * steps are:
- *
- * i) plug io further to this physical block. (see bio_prison code).
- *
- * ii) quiesce any read io to that shared data block. Obviously
- * including all devices that share this block. (see deferred_set code)
- *
- * iii) copy the data block to a newly allocate block. This step can be
- * missed out if the io covers the block. (schedule_copy).
- *
- * iv) insert the new mapping into the origin's btree
- * (process_prepared_mapping). This act of inserting breaks some
- * sharing of btree nodes between the two devices. Breaking sharing only
- * effects the btree of that specific device. Btrees for the other
- * devices that share the block never change. The btree for the origin
- * device as it was after the last commit is untouched, ie. we're using
- * persistent data structures in the functional programming sense.
- *
- * v) unplug io to this physical block, including the io that triggered
- * the breaking of sharing.
- *
- * Steps (ii) and (iii) occur in parallel.
- *
- * The metadata _doesn't_ need to be committed before the io continues. We
- * get away with this because the io is always written to a _new_ block.
- * If there's a crash, then:
- *
- * - The origin mapping will point to the old origin block (the shared
- * one). This will contain the data as it was before the io that triggered
- * the breaking of sharing came in.
- *
- * - The snap mapping still points to the old block. As it would after
- * the commit.
- *
- * The downside of this scheme is the timestamp magic isn't perfect, and
- * will continue to think that data block in the snapshot device is shared
- * even after the write to the origin has broken sharing. I suspect data
- * blocks will typically be shared by many different devices, so we're
- * breaking sharing n + 1 times, rather than n, where n is the number of
- * devices that reference this data block. At the moment I think the
- * benefits far, far outweigh the disadvantages.
- */
-
-/*----------------------------------------------------------------*/
-
-/*
- * Sometimes we can't deal with a bio straight away. We put them in prison
- * where they can't cause any mischief. Bios are put in a cell identified
- * by a key, multiple bios can be in the same cell. When the cell is
- * subsequently unlocked the bios become available.
- */
-struct bio_prison;
-
-struct cell_key {
- int virtual;
- dm_thin_id dev;
- dm_block_t block;
-};
-
-struct cell {
- struct hlist_node list;
- struct bio_prison *prison;
- struct cell_key key;
- struct bio *holder;
- struct bio_list bios;
-};
-
-struct bio_prison {
- spinlock_t lock;
- mempool_t *cell_pool;
-
- unsigned nr_buckets;
- unsigned hash_mask;
- struct hlist_head *cells;
-};
-
-static uint32_t calc_nr_buckets(unsigned nr_cells)
-{
- uint32_t n = 128;
-
- nr_cells /= 4;
- nr_cells = min(nr_cells, 8192u);
-
- while (n < nr_cells)
- n <<= 1;
-
- return n;
-}
-
-/*
- * @nr_cells should be the number of cells you want in use _concurrently_.
- * Don't confuse it with the number of distinct keys.
- */
-static struct bio_prison *prison_create(unsigned nr_cells)
-{
- unsigned i;
- uint32_t nr_buckets = calc_nr_buckets(nr_cells);
- size_t len = sizeof(struct bio_prison) +
- (sizeof(struct hlist_head) * nr_buckets);
- struct bio_prison *prison = kmalloc(len, GFP_KERNEL);
-
- if (!prison)
- return NULL;
-
- spin_lock_init(&prison->lock);
- prison->cell_pool = mempool_create_kmalloc_pool(nr_cells,
- sizeof(struct cell));
- if (!prison->cell_pool) {
- kfree(prison);
- return NULL;
- }
-
- prison->nr_buckets = nr_buckets;
- prison->hash_mask = nr_buckets - 1;
- prison->cells = (struct hlist_head *) (prison + 1);
- for (i = 0; i < nr_buckets; i++)
- INIT_HLIST_HEAD(prison->cells + i);
-
- return prison;
-}
-
-static void prison_destroy(struct bio_prison *prison)
-{
- mempool_destroy(prison->cell_pool);
- kfree(prison);
-}
-
-static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
-{
- const unsigned long BIG_PRIME = 4294967291UL;
- uint64_t hash = key->block * BIG_PRIME;
-
- return (uint32_t) (hash & prison->hash_mask);
-}
-
-static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
-{
- return (lhs->virtual == rhs->virtual) &&
- (lhs->dev == rhs->dev) &&
- (lhs->block == rhs->block);
-}
-
-static struct cell *__search_bucket(struct hlist_head *bucket,
- struct cell_key *key)
-{
- struct cell *cell;
- struct hlist_node *tmp;
-
- hlist_for_each_entry(cell, tmp, bucket, list)
- if (keys_equal(&cell->key, key))
- return cell;
-
- return NULL;
-}
-
-/*
- * This may block if a new cell needs allocating. You must ensure that
- * cells will be unlocked even if the calling thread is blocked.
- *
- * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
- */
-static int bio_detain(struct bio_prison *prison, struct cell_key *key,
- struct bio *inmate, struct cell **ref)
-{
- int r = 1;
- unsigned long flags;
- uint32_t hash = hash_key(prison, key);
- struct cell *cell, *cell2;
-
- BUG_ON(hash > prison->nr_buckets);
-
- spin_lock_irqsave(&prison->lock, flags);
-
- cell = __search_bucket(prison->cells + hash, key);
- if (cell) {
- bio_list_add(&cell->bios, inmate);
- goto out;
- }
-
- /*
- * Allocate a new cell
- */
- spin_unlock_irqrestore(&prison->lock, flags);
- cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO);
- spin_lock_irqsave(&prison->lock, flags);
-
- /*
- * We've been unlocked, so we have to double check that
- * nobody else has inserted this cell in the meantime.
- */
- cell = __search_bucket(prison->cells + hash, key);
- if (cell) {
- mempool_free(cell2, prison->cell_pool);
- bio_list_add(&cell->bios, inmate);
- goto out;
- }
-
- /*
- * Use new cell.
- */
- cell = cell2;
-
- cell->prison = prison;
- memcpy(&cell->key, key, sizeof(cell->key));
- cell->holder = inmate;
- bio_list_init(&cell->bios);
- hlist_add_head(&cell->list, prison->cells + hash);
-
- r = 0;
-
-out:
- spin_unlock_irqrestore(&prison->lock, flags);
-
- *ref = cell;
-
- return r;
-}
-
-/*
- * @inmates must have been initialised prior to this call
- */
-static void __cell_release(struct cell *cell, struct bio_list *inmates)
-{
- struct bio_prison *prison = cell->prison;
-
- hlist_del(&cell->list);
-
- if (inmates) {
- bio_list_add(inmates, cell->holder);
- bio_list_merge(inmates, &cell->bios);
- }
-
- mempool_free(cell, prison->cell_pool);
-}
-
-static void cell_release(struct cell *cell, struct bio_list *bios)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release(cell, bios);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-/*
- * There are a couple of places where we put a bio into a cell briefly
- * before taking it out again. In these situations we know that no other
- * bio may be in the cell. This function releases the cell, and also does
- * a sanity check.
- */
-static void __cell_release_singleton(struct cell *cell, struct bio *bio)
-{
- BUG_ON(cell->holder != bio);
- BUG_ON(!bio_list_empty(&cell->bios));
-
- __cell_release(cell, NULL);
-}
-
-static void cell_release_singleton(struct cell *cell, struct bio *bio)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release_singleton(cell, bio);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-/*
- * Sometimes we don't want the holder, just the additional bios.
- */
-static void __cell_release_no_holder(struct cell *cell, struct bio_list *inmates)
-{
- struct bio_prison *prison = cell->prison;
-
- hlist_del(&cell->list);
- bio_list_merge(inmates, &cell->bios);
-
- mempool_free(cell, prison->cell_pool);
-}
-
-static void cell_release_no_holder(struct cell *cell, struct bio_list *inmates)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release_no_holder(cell, inmates);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-static void cell_error(struct cell *cell)
-{
- struct bio_prison *prison = cell->prison;
- struct bio_list bios;
- struct bio *bio;
- unsigned long flags;
-
- bio_list_init(&bios);
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release(cell, &bios);
- spin_unlock_irqrestore(&prison->lock, flags);
-
- while ((bio = bio_list_pop(&bios)))
- bio_io_error(bio);
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * We use the deferred set to keep track of pending reads to shared blocks.
- * We do this to ensure the new mapping caused by a write isn't performed
- * until these prior reads have completed. Otherwise the insertion of the
- * new mapping could free the old block that the read bios are mapped to.
- */
-
-struct deferred_set;
-struct deferred_entry {
- struct deferred_set *ds;
- unsigned count;
- struct list_head work_items;
-};
-
-struct deferred_set {
- spinlock_t lock;
- unsigned current_entry;
- unsigned sweeper;
- struct deferred_entry entries[DEFERRED_SET_SIZE];
-};
-
-static void ds_init(struct deferred_set *ds)
-{
- int i;
-
- spin_lock_init(&ds->lock);
- ds->current_entry = 0;
- ds->sweeper = 0;
- for (i = 0; i < DEFERRED_SET_SIZE; i++) {
- ds->entries[i].ds = ds;
- ds->entries[i].count = 0;
- INIT_LIST_HEAD(&ds->entries[i].work_items);
- }
-}
-
-static struct deferred_entry *ds_inc(struct deferred_set *ds)
-{
- unsigned long flags;
- struct deferred_entry *entry;
-
- spin_lock_irqsave(&ds->lock, flags);
- entry = ds->entries + ds->current_entry;
- entry->count++;
- spin_unlock_irqrestore(&ds->lock, flags);
-
- return entry;
-}
-
-static unsigned ds_next(unsigned index)
-{
- return (index + 1) % DEFERRED_SET_SIZE;
-}
-
-static void __sweep(struct deferred_set *ds, struct list_head *head)
-{
- while ((ds->sweeper != ds->current_entry) &&
- !ds->entries[ds->sweeper].count) {
- list_splice_init(&ds->entries[ds->sweeper].work_items, head);
- ds->sweeper = ds_next(ds->sweeper);
- }
-
- if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count)
- list_splice_init(&ds->entries[ds->sweeper].work_items, head);
-}
-
-static void ds_dec(struct deferred_entry *entry, struct list_head *head)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&entry->ds->lock, flags);
- BUG_ON(!entry->count);
- --entry->count;
- __sweep(entry->ds, head);
- spin_unlock_irqrestore(&entry->ds->lock, flags);
-}
-
-/*
- * Returns 1 if deferred or 0 if no pending items to delay job.
- */
-static int ds_add_work(struct deferred_set *ds, struct list_head *work)
-{
- int r = 1;
- unsigned long flags;
- unsigned next_entry;
-
- spin_lock_irqsave(&ds->lock, flags);
- if ((ds->sweeper == ds->current_entry) &&
- !ds->entries[ds->current_entry].count)
- r = 0;
- else {
- list_add(work, &ds->entries[ds->current_entry].work_items);
- next_entry = ds_next(ds->current_entry);
- if (!ds->entries[next_entry].count)
- ds->current_entry = next_entry;
- }
- spin_unlock_irqrestore(&ds->lock, flags);
-
- return r;
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * Key building.
- */
-static void build_data_key(struct dm_thin_device *td,
- dm_block_t b, struct cell_key *key)
-{
- key->virtual = 0;
- key->dev = dm_thin_dev_id(td);
- key->block = b;
-}
-
-static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
- struct cell_key *key)
-{
- key->virtual = 1;
- key->dev = dm_thin_dev_id(td);
- key->block = b;
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * A pool device ties together a metadata device and a data device. It
- * also provides the interface for creating and destroying internal
- * devices.
- */
-struct new_mapping;
-
-struct pool_features {
- unsigned zero_new_blocks:1;
- unsigned discard_enabled:1;
- unsigned discard_passdown:1;
-};
-
-struct pool {
- struct list_head list;
- struct dm_target *ti; /* Only set if a pool target is bound */
-
- struct mapped_device *pool_md;
- struct block_device *md_dev;
- struct dm_pool_metadata *pmd;
-
- uint32_t sectors_per_block;
- unsigned block_shift;
- dm_block_t offset_mask;
- dm_block_t low_water_blocks;
-
- struct pool_features pf;
- unsigned low_water_triggered:1; /* A dm event has been sent */
- unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
-
- struct bio_prison *prison;
- struct dm_kcopyd_client *copier;
-
- struct workqueue_struct *wq;
- struct work_struct worker;
- struct delayed_work waker;
-
- unsigned ref_count;
- unsigned long last_commit_jiffies;
-
- spinlock_t lock;
- struct bio_list deferred_bios;
- struct bio_list deferred_flush_bios;
- struct list_head prepared_mappings;
- struct list_head prepared_discards;
-
- struct bio_list retry_on_resume_list;
-
- struct deferred_set shared_read_ds;
- struct deferred_set all_io_ds;
-
- struct new_mapping *next_mapping;
- mempool_t *mapping_pool;
- mempool_t *endio_hook_pool;
-};
-
-/*
- * Target context for a pool.
- */
-struct pool_c {
- struct dm_target *ti;
- struct pool *pool;
- struct dm_dev *data_dev;
- struct dm_dev *metadata_dev;
- struct dm_target_callbacks callbacks;
-
- dm_block_t low_water_blocks;
- struct pool_features pf;
-};
-
-/*
- * Target context for a thin.
- */
-struct thin_c {
- struct dm_dev *pool_dev;
- struct dm_dev *origin_dev;
- dm_thin_id dev_id;
-
- struct pool *pool;
- struct dm_thin_device *td;
-};
-
-/*----------------------------------------------------------------*/
-
-/*
- * A global list of pools that uses a struct mapped_device as a key.
- */
-static struct dm_thin_pool_table {
- struct mutex mutex;
- struct list_head pools;
-} dm_thin_pool_table;
-
-static void pool_table_init(void)
-{
- mutex_init(&dm_thin_pool_table.mutex);
- INIT_LIST_HEAD(&dm_thin_pool_table.pools);
-}
-
-static void __pool_table_insert(struct pool *pool)
-{
- BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
- list_add(&pool->list, &dm_thin_pool_table.pools);
-}
-
-static void __pool_table_remove(struct pool *pool)
-{
- BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
- list_del(&pool->list);
-}
-
-static struct pool *__pool_table_lookup(struct mapped_device *md)
-{
- struct pool *pool = NULL, *tmp;
-
- BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
-
- list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
- if (tmp->pool_md == md) {
- pool = tmp;
- break;
- }
- }
-
- return pool;
-}
-
-static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
-{
- struct pool *pool = NULL, *tmp;
-
- BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
-
- list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
- if (tmp->md_dev == md_dev) {
- pool = tmp;
- break;
- }
- }
-
- return pool;
-}
-
-/*----------------------------------------------------------------*/
-
-struct endio_hook {
- struct thin_c *tc;
- struct deferred_entry *shared_read_entry;
- struct deferred_entry *all_io_entry;
- struct new_mapping *overwrite_mapping;
-};
-
-static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
-{
- struct bio *bio;
- struct bio_list bios;
-
- bio_list_init(&bios);
- bio_list_merge(&bios, master);
- bio_list_init(master);
-
- while ((bio = bio_list_pop(&bios))) {
- struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
- if (h->tc == tc)
- bio_endio(bio, DM_ENDIO_REQUEUE);
- else
- bio_list_add(master, bio);
- }
-}
-
-static void requeue_io(struct thin_c *tc)
-{
- struct pool *pool = tc->pool;
- unsigned long flags;
-
- spin_lock_irqsave(&pool->lock, flags);
- __requeue_bio_list(tc, &pool->deferred_bios);
- __requeue_bio_list(tc, &pool->retry_on_resume_list);
- spin_unlock_irqrestore(&pool->lock, flags);
-}
-
-/*
- * This section of code contains the logic for processing a thin device's IO.
- * Much of the code depends on pool object resources (lists, workqueues, etc)
- * but most is exclusively called from the thin target rather than the thin-pool
- * target.
- */
-
-static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
-{
- return bio->bi_sector >> tc->pool->block_shift;
-}
-
-static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
-{
- struct pool *pool = tc->pool;
-
- bio->bi_bdev = tc->pool_dev->bdev;
- bio->bi_sector = (block << pool->block_shift) +
- (bio->bi_sector & pool->offset_mask);
-}
-
-static void remap_to_origin(struct thin_c *tc, struct bio *bio)
-{
- bio->bi_bdev = tc->origin_dev->bdev;
-}
-
-static void issue(struct thin_c *tc, struct bio *bio)
-{
- struct pool *pool = tc->pool;
- unsigned long flags;
-
- /*
- * Batch together any FUA/FLUSH bios we find and then issue
- * a single commit for them in process_deferred_bios().
- */
- if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_add(&pool->deferred_flush_bios, bio);
- spin_unlock_irqrestore(&pool->lock, flags);
- } else
- generic_make_request(bio);
-}
-
-static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
-{
- remap_to_origin(tc, bio);
- issue(tc, bio);
-}
-
-static void remap_and_issue(struct thin_c *tc, struct bio *bio,
- dm_block_t block)
-{
- remap(tc, bio, block);
- issue(tc, bio);
-}
-
-/*
- * wake_worker() is used when new work is queued and when pool_resume is
- * ready to continue deferred IO processing.
- */
-static void wake_worker(struct pool *pool)
-{
- queue_work(pool->wq, &pool->worker);
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * Bio endio functions.
- */
-struct new_mapping {
- struct list_head list;
-
- unsigned quiesced:1;
- unsigned prepared:1;
- unsigned pass_discard:1;
-
- struct thin_c *tc;
- dm_block_t virt_block;
- dm_block_t data_block;
- struct cell *cell, *cell2;
- int err;
-
- /*
- * 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 new_mapping *m)
-{
- struct pool *pool = m->tc->pool;
-
- if (m->quiesced && m->prepared) {
- list_add(&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 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 = 1;
- __maybe_add_mapping(m);
- spin_unlock_irqrestore(&pool->lock, flags);
-}
-
-static void overwrite_endio(struct bio *bio, int err)
-{
- unsigned long flags;
- struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
- struct new_mapping *m = h->overwrite_mapping;
- struct pool *pool = m->tc->pool;
-
- m->err = err;
-
- spin_lock_irqsave(&pool->lock, flags);
- m->prepared = 1;
- __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 cell *cell,
- dm_block_t data_block)
-{
- struct pool *pool = tc->pool;
- unsigned long flags;
-
- spin_lock_irqsave(&pool->lock, flags);
- cell_release(cell, &pool->deferred_bios);
- spin_unlock_irqrestore(&tc->pool->lock, flags);
-
- wake_worker(pool);
-}
-
-/*
- * Same as cell_defer above, except it omits one particular detainee,
- * a write bio that covers the block and has already been processed.
- */
-static void cell_defer_except(struct thin_c *tc, struct cell *cell)
-{
- struct bio_list bios;
- struct pool *pool = tc->pool;
- unsigned long flags;
-
- bio_list_init(&bios);
-
- spin_lock_irqsave(&pool->lock, flags);
- cell_release_no_holder(cell, &pool->deferred_bios);
- spin_unlock_irqrestore(&pool->lock, flags);
-
- wake_worker(pool);
-}
-
-static void process_prepared_mapping(struct new_mapping *m)
-{
- struct thin_c *tc = m->tc;
- struct bio *bio;
- int r;
-
- bio = m->bio;
- if (bio)
- bio->bi_end_io = m->saved_bi_end_io;
-
- if (m->err) {
- cell_error(m->cell);
- return;
- }
-
- /*
- * 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) {
- DMERR("dm_thin_insert_block() failed");
- cell_error(m->cell);
- return;
- }
-
- /*
- * 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_except(tc, m->cell);
- bio_endio(bio, 0);
- } else
- cell_defer(tc, m->cell, m->data_block);
-
- list_del(&m->list);
- mempool_free(m, tc->pool->mapping_pool);
-}
-
-static void process_prepared_discard(struct new_mapping *m)
-{
- int r;
- struct thin_c *tc = m->tc;
-
- r = dm_thin_remove_block(tc->td, m->virt_block);
- if (r)
- DMERR("dm_thin_remove_block() failed");
-
- /*
- * Pass the discard down to the underlying device?
- */
- if (m->pass_discard)
- remap_and_issue(tc, m->bio, m->data_block);
- else
- bio_endio(m->bio, 0);
-
- cell_defer_except(tc, m->cell);
- cell_defer_except(tc, m->cell2);
- mempool_free(m, tc->pool->mapping_pool);
-}
-
-static void process_prepared(struct pool *pool, struct list_head *head,
- void (*fn)(struct new_mapping *))
-{
- unsigned long flags;
- struct list_head maps;
- struct 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_sector & pool->offset_mask) &&
- (bio->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 new_mapping *get_next_mapping(struct pool *pool)
-{
- struct new_mapping *r = pool->next_mapping;
-
- BUG_ON(!pool->next_mapping);
-
- pool->next_mapping = NULL;
-
- return r;
-}
-
-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 cell *cell, struct bio *bio)
-{
- int r;
- struct pool *pool = tc->pool;
- struct new_mapping *m = get_next_mapping(pool);
-
- INIT_LIST_HEAD(&m->list);
- m->quiesced = 0;
- m->prepared = 0;
- m->tc = tc;
- m->virt_block = virt_block;
- m->data_block = data_dest;
- m->cell = cell;
- m->err = 0;
- m->bio = NULL;
-
- if (!ds_add_work(&pool->shared_read_ds, &m->list))
- m->quiesced = 1;
-
- /*
- * 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 endio_hook *h = dm_get_mapinfo(bio)->ptr;
- h->overwrite_mapping = m;
- m->bio = bio;
- save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
- 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("dm_kcopyd_copy() failed");
- cell_error(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 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 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 cell *cell,
- struct bio *bio)
-{
- struct pool *pool = tc->pool;
- struct new_mapping *m = get_next_mapping(pool);
-
- INIT_LIST_HEAD(&m->list);
- m->quiesced = 1;
- m->prepared = 0;
- m->tc = tc;
- m->virt_block = virt_block;
- m->data_block = data_block;
- m->cell = cell;
- m->err = 0;
- m->bio = NULL;
-
- /*
- * 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 endio_hook *h = dm_get_mapinfo(bio)->ptr;
- h->overwrite_mapping = m;
- m->bio = bio;
- save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
- 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("dm_kcopyd_zero() failed");
- cell_error(cell);
- }
- }
-}
-
-static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
-{
- int r;
- dm_block_t free_blocks;
- unsigned long flags;
- struct pool *pool = tc->pool;
-
- r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
- if (r)
- return r;
-
- if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
- DMWARN("%s: reached low water mark, sending event.",
- dm_device_name(pool->pool_md));
- spin_lock_irqsave(&pool->lock, flags);
- pool->low_water_triggered = 1;
- spin_unlock_irqrestore(&pool->lock, flags);
- dm_table_event(pool->ti->table);
- }
-
- if (!free_blocks) {
- if (pool->no_free_space)
- return -ENOSPC;
- else {
- /*
- * Try to commit to see if that will free up some
- * more space.
- */
- r = dm_pool_commit_metadata(pool->pmd);
- if (r) {
- DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
- __func__, r);
- return r;
- }
-
- r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
- if (r)
- return r;
-
- /*
- * If we still have no space we set a flag to avoid
- * doing all this checking and return -ENOSPC.
- */
- if (!free_blocks) {
- DMWARN("%s: no free space available.",
- dm_device_name(pool->pool_md));
- spin_lock_irqsave(&pool->lock, flags);
- pool->no_free_space = 1;
- spin_unlock_irqrestore(&pool->lock, flags);
- return -ENOSPC;
- }
- }
- }
-
- r = dm_pool_alloc_data_block(pool->pmd, result);
- if (r)
- return r;
-
- return 0;
-}
-
-/*
- * If we have run out of space, queue bios until the device is
- * resumed, presumably after having been reloaded with more space.
- */
-static void retry_on_resume(struct bio *bio)
-{
- struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
- struct thin_c *tc = h->tc;
- struct pool *pool = tc->pool;
- unsigned long flags;
-
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_add(&pool->retry_on_resume_list, bio);
- spin_unlock_irqrestore(&pool->lock, flags);
-}
-
-static void no_space(struct cell *cell)
-{
- struct bio *bio;
- struct bio_list bios;
-
- bio_list_init(&bios);
- cell_release(cell, &bios);
-
- 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 cell *cell, *cell2;
- struct cell_key key, key2;
- dm_block_t block = get_bio_block(tc, bio);
- struct dm_thin_lookup_result lookup_result;
- struct new_mapping *m;
-
- build_virtual_key(tc->td, block, &key);
- if (bio_detain(tc->pool->prison, &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->prison, &key2, bio, &cell2)) {
- cell_release_singleton(cell, bio);
- 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 = (!lookup_result.shared) & pool->pf.discard_passdown;
- m->virt_block = block;
- m->data_block = lookup_result.block;
- m->cell = cell;
- m->cell2 = cell2;
- m->err = 0;
- m->bio = bio;
-
- if (!ds_add_work(&pool->all_io_ds, &m->list)) {
- spin_lock_irqsave(&pool->lock, flags);
- list_add(&m->list, &pool->prepared_discards);
- spin_unlock_irqrestore(&pool->lock, flags);
- wake_worker(pool);
- }
- } else {
- /*
- * This path is hit if people are ignoring
- * limits->discard_granularity. It ignores any
- * part of the discard that is in a subsequent
- * block.
- */
- sector_t offset = bio->bi_sector - (block << pool->block_shift);
- unsigned remaining = (pool->sectors_per_block - offset) << 9;
- bio->bi_size = min(bio->bi_size, remaining);
-
- cell_release_singleton(cell, bio);
- cell_release_singleton(cell2, bio);
- remap_and_issue(tc, bio, lookup_result.block);
- }
- break;
-
- case -ENODATA:
- /*
- * It isn't provisioned, just forget it.
- */
- cell_release_singleton(cell, bio);
- bio_endio(bio, 0);
- break;
-
- default:
- DMERR("discard: find block unexpectedly returned %d", r);
- cell_release_singleton(cell, bio);
- bio_io_error(bio);
- break;
- }
-}
-
-static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
- struct cell_key *key,
- struct dm_thin_lookup_result *lookup_result,
- struct cell *cell)
-{
- int r;
- dm_block_t data_block;
-
- 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:
- no_space(cell);
- break;
-
- default:
- DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
- cell_error(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 cell *cell;
- struct pool *pool = tc->pool;
- struct 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->prison, &key, bio, &cell))
- return;
-
- if (bio_data_dir(bio) == WRITE)
- break_sharing(tc, bio, block, &key, lookup_result, cell);
- else {
- struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
-
- h->shared_read_entry = ds_inc(&pool->shared_read_ds);
-
- cell_release_singleton(cell, bio);
- remap_and_issue(tc, bio, lookup_result->block);
- }
-}
-
-static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
- struct cell *cell)
-{
- int r;
- dm_block_t data_block;
-
- /*
- * Remap empty bios (flushes) immediately, without provisioning.
- */
- if (!bio->bi_size) {
- cell_release_singleton(cell, bio);
- 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_release_singleton(cell, bio);
- 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:
- no_space(cell);
- break;
-
- default:
- DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
- cell_error(cell);
- break;
- }
-}
-
-static void process_bio(struct thin_c *tc, struct bio *bio)
-{
- int r;
- dm_block_t block = get_bio_block(tc, bio);
- struct cell *cell;
- struct 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(tc->pool->prison, &key, bio, &cell))
- return;
-
- r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
- switch (r) {
- case 0:
- /*
- * We can release this cell now. This thread is the only
- * one that puts bios into a cell, and we know there were
- * no preceding bios.
- */
- /*
- * TODO: this will probably have to change when discard goes
- * back in.
- */
- cell_release_singleton(cell, bio);
-
- if (lookup_result.shared)
- process_shared_bio(tc, bio, block, &lookup_result);
- else
- remap_and_issue(tc, bio, lookup_result.block);
- break;
-
- case -ENODATA:
- if (bio_data_dir(bio) == READ && tc->origin_dev) {
- cell_release_singleton(cell, bio);
- remap_to_origin_and_issue(tc, bio);
- } else
- provision_block(tc, bio, block, cell);
- break;
-
- default:
- DMERR("dm_thin_find_block() failed, error = %d", r);
- cell_release_singleton(cell, bio);
- bio_io_error(bio);
- break;
- }
-}
-
-static int need_commit_due_to_time(struct pool *pool)
-{
- return jiffies < pool->last_commit_jiffies ||
- jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
-}
-
-static void process_deferred_bios(struct pool *pool)
-{
- unsigned long flags;
- struct bio *bio;
- struct bio_list bios;
- int r;
-
- bio_list_init(&bios);
-
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_merge(&bios, &pool->deferred_bios);
- bio_list_init(&pool->deferred_bios);
- spin_unlock_irqrestore(&pool->lock, flags);
-
- while ((bio = bio_list_pop(&bios))) {
- struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
- struct thin_c *tc = h->tc;
-
- /*
- * 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(&pool->lock, flags);
- bio_list_merge(&pool->deferred_bios, &bios);
- spin_unlock_irqrestore(&pool->lock, flags);
-
- break;
- }
-
- if (bio->bi_rw & REQ_DISCARD)
- process_discard(tc, bio);
- else
- process_bio(tc, bio);
- }
-
- /*
- * 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) && !need_commit_due_to_time(pool))
- return;
-
- r = dm_pool_commit_metadata(pool->pmd);
- if (r) {
- DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
- __func__, r);
- 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, process_prepared_mapping);
- process_prepared(pool, &pool->prepared_discards, 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);
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * 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(&pool->lock, flags);
- bio_list_add(&pool->deferred_bios, bio);
- spin_unlock_irqrestore(&pool->lock, flags);
-
- wake_worker(pool);
-}
-
-static struct endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *bio)
-{
- struct pool *pool = tc->pool;
- struct endio_hook *h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO);
-
- h->tc = tc;
- h->shared_read_entry = NULL;
- h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds);
- h->overwrite_mapping = NULL;
-
- return h;
-}
-
-/*
- * Non-blocking function called from the thin target's map function.
- */
-static int thin_bio_map(struct dm_target *ti, struct bio *bio,
- union map_info *map_context)
-{
- 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;
-
- map_context->ptr = thin_hook_bio(tc, bio);
- 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);
- r = DM_MAPIO_SUBMITTED;
- } else {
- remap(tc, bio, result.block);
- r = DM_MAPIO_REMAPPED;
- }
- break;
-
- case -ENODATA:
- /*
- * In future, the failed dm_thin_find_block above could
- * provide the hint to load the metadata into cache.
- */
- case -EWOULDBLOCK:
- thin_defer_bio(tc, bio);
- r = DM_MAPIO_SUBMITTED;
- break;
- }
-
- return r;
-}
-
-static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
-{
- int r;
- unsigned long flags;
- struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
-
- spin_lock_irqsave(&pt->pool->lock, flags);
- r = !bio_list_empty(&pt->pool->retry_on_resume_list);
- spin_unlock_irqrestore(&pt->pool->lock, flags);
-
- if (!r) {
- struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
- r = bdi_congested(&q->backing_dev_info, bdi_bits);
- }
-
- return r;
-}
-
-static void __requeue_bios(struct pool *pool)
-{
- bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
- bio_list_init(&pool->retry_on_resume_list);
-}
-
-/*----------------------------------------------------------------
- * Binding of control targets to a pool object
- *--------------------------------------------------------------*/
-static int bind_control_target(struct pool *pool, struct dm_target *ti)
-{
- struct pool_c *pt = ti->private;
-
- pool->ti = ti;
- pool->low_water_blocks = pt->low_water_blocks;
- pool->pf = pt->pf;
-
- /*
- * If discard_passdown was enabled verify that the data device
- * supports discards. Disable discard_passdown if not; otherwise
- * -EOPNOTSUPP will be returned.
- */
- if (pt->pf.discard_passdown) {
- struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
- if (!q || !blk_queue_discard(q)) {
- char buf[BDEVNAME_SIZE];
- DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.",
- bdevname(pt->data_dev->bdev, buf));
- pool->pf.discard_passdown = 0;
- }
- }
-
- 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->zero_new_blocks = 1;
- pf->discard_enabled = 1;
- pf->discard_passdown = 1;
-}
-
-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__);
-
- 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);
- mempool_destroy(pool->endio_hook_pool);
- kfree(pool);
-}
-
-static struct pool *pool_create(struct mapped_device *pool_md,
- struct block_device *metadata_dev,
- unsigned long block_size, char **error)
-{
- int r;
- void *err_p;
- struct pool *pool;
- struct dm_pool_metadata *pmd;
-
- pmd = dm_pool_metadata_open(metadata_dev, block_size);
- 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;
- pool->block_shift = ffs(block_size) - 1;
- pool->offset_mask = block_size - 1;
- pool->low_water_blocks = 0;
- pool_features_init(&pool->pf);
- pool->prison = 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();
- 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_bios);
- bio_list_init(&pool->deferred_flush_bios);
- INIT_LIST_HEAD(&pool->prepared_mappings);
- INIT_LIST_HEAD(&pool->prepared_discards);
- pool->low_water_triggered = 0;
- pool->no_free_space = 0;
- bio_list_init(&pool->retry_on_resume_list);
- ds_init(&pool->shared_read_ds);
- ds_init(&pool->all_io_ds);
-
- pool->next_mapping = NULL;
- pool->mapping_pool =
- mempool_create_kmalloc_pool(MAPPING_POOL_SIZE, sizeof(struct new_mapping));
- if (!pool->mapping_pool) {
- *error = "Error creating pool's mapping mempool";
- err_p = ERR_PTR(-ENOMEM);
- goto bad_mapping_pool;
- }
-
- pool->endio_hook_pool =
- mempool_create_kmalloc_pool(ENDIO_HOOK_POOL_SIZE, sizeof(struct endio_hook));
- if (!pool->endio_hook_pool) {
- *error = "Error creating pool's endio_hook mempool";
- err_p = ERR_PTR(-ENOMEM);
- goto bad_endio_hook_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_endio_hook_pool:
- mempool_destroy(pool->mapping_pool);
-bad_mapping_pool:
- destroy_workqueue(pool->wq);
-bad_wq:
- dm_kcopyd_client_destroy(pool->copier);
-bad_kcopyd_client:
- 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, char **error,
- int *created)
-{
- struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
-
- if (pool) {
- if (pool->pool_md != pool_md)
- return ERR_PTR(-EBUSY);
- __pool_inc(pool);
-
- } else {
- pool = __pool_table_lookup(pool_md);
- if (pool) {
- if (pool->md_dev != metadata_dev)
- return ERR_PTR(-EINVAL);
- __pool_inc(pool);
-
- } else {
- pool = pool_create(pool_md, metadata_dev, block_size, 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, 3, "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 = 0;
- continue;
- } else if (!strcasecmp(arg_name, "ignore_discard")) {
- pf->discard_enabled = 0;
- continue;
- } else if (!strcasecmp(arg_name, "no_discard_passdown")) {
- pf->discard_passdown = 0;
- continue;
- }
-
- ti->error = "Unrecognised pool feature requested";
- r = -EINVAL;
- }
-
- return r;
-}
-
-/*
- * 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
- */
-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;
- sector_t metadata_dev_size;
- char b[BDEVNAME_SIZE];
-
- /*
- * 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;
-
- r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev);
- if (r) {
- ti->error = "Error opening metadata block device";
- goto out_unlock;
- }
-
- metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;
- 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(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS);
-
- 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 ||
- !is_power_of_2(block_size)) {
- 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;
- }
-
- /*
- * Set default pool features.
- */
- pool_features_init(&pf);
-
- dm_consume_args(&as, 4);
- r = parse_pool_features(&as, &pf, ti);
- if (r)
- 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, &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->pf = pf;
- ti->num_flush_requests = 1;
- /*
- * Only need to enable discards if the pool should pass
- * them down to the data device. The thin device's discard
- * processing will cause mappings to be removed from the btree.
- */
- if (pf.discard_enabled && pf.discard_passdown) {
- ti->num_discard_requests = 1;
- /*
- * Setting 'discards_supported' circumvents the normal
- * stacking of discard limits (this keeps the pool and
- * thin devices' discard limits consistent).
- */
- ti->discards_supported = 1;
- }
- ti->private = 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,
- union map_info *map_context)
-{
- 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;
-}
-
-/*
- * 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;
- struct pool_c *pt = ti->private;
- struct pool *pool = pt->pool;
- dm_block_t data_size, sb_data_size;
-
- /*
- * Take control of the pool object.
- */
- r = bind_control_target(pool, ti);
- if (r)
- return r;
-
- data_size = ti->len >> pool->block_shift;
- r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
- if (r) {
- DMERR("failed to retrieve data device size");
- return r;
- }
-
- if (data_size < sb_data_size) {
- DMERR("pool target too small, is %llu blocks (expected %llu)",
- data_size, sb_data_size);
- return -EINVAL;
-
- } else if (data_size > sb_data_size) {
- r = dm_pool_resize_data_dev(pool->pmd, data_size);
- if (r) {
- DMERR("failed to resize data device");
- return r;
- }
-
- r = dm_pool_commit_metadata(pool->pmd);
- if (r) {
- DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
- __func__, r);
- return r;
- }
- }
-
- 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 = 0;
- pool->no_free_space = 0;
- __requeue_bios(pool);
- spin_unlock_irqrestore(&pool->lock, flags);
-
- do_waker(&pool->waker.work);
-}
-
-static void pool_postsuspend(struct dm_target *ti)
-{
- int r;
- struct pool_c *pt = ti->private;
- struct pool *pool = pt->pool;
-
- cancel_delayed_work(&pool->waker);
- flush_workqueue(pool->wq);
-
- r = dm_pool_commit_metadata(pool->pmd);
- if (r < 0) {
- DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
- __func__, r);
- /* FIXME: invalidate device? error the next FUA or FLUSH bio ?*/
- }
-}
-
-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;
-}
-
-/*
- * 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>
- */
-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
- DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
-
- if (!r) {
- r = dm_pool_commit_metadata(pool->pmd);
- if (r)
- DMERR("%s message: dm_pool_commit_metadata() failed, error = %d",
- argv[0], r);
- }
-
- return r;
-}
-
-/*
- * Status line is:
- * <transaction id> <used metadata sectors>/<total metadata sectors>
- * <used data sectors>/<total data sectors> <held metadata root>
- */
-static int pool_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
-{
- int r, count;
- 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:
- r = dm_pool_get_metadata_transaction_id(pool->pmd,
- &transaction_id);
- if (r)
- return r;
-
- r = dm_pool_get_free_metadata_block_count(pool->pmd,
- &nr_free_blocks_metadata);
- if (r)
- return r;
-
- r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
- if (r)
- return r;
-
- r = dm_pool_get_free_block_count(pool->pmd,
- &nr_free_blocks_data);
- if (r)
- return r;
-
- r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
- if (r)
- return r;
-
- r = dm_pool_get_held_metadata_root(pool->pmd, &held_root);
- if (r)
- return r;
-
- 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("-");
-
- 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);
-
- count = !pool->pf.zero_new_blocks + !pool->pf.discard_enabled +
- !pt->pf.discard_passdown;
- DMEMIT("%u ", count);
-
- if (!pool->pf.zero_new_blocks)
- DMEMIT("skip_block_zeroing ");
-
- if (!pool->pf.discard_enabled)
- DMEMIT("ignore_discard ");
-
- if (!pt->pf.discard_passdown)
- DMEMIT("no_discard_passdown ");
-
- break;
- }
-
- return 0;
-}
-
-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 *pool, struct queue_limits *limits)
-{
- /*
- * FIXME: these limits may be incompatible with the pool's data device
- */
- limits->max_discard_sectors = pool->sectors_per_block;
-
- /*
- * This is just a hint, and not enforced. We have to cope with
- * bios that overlap 2 blocks.
- */
- limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
- limits->discard_zeroes_data = pool->pf.zero_new_blocks;
-}
-
-static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
-{
- struct pool_c *pt = ti->private;
- struct pool *pool = pt->pool;
-
- blk_limits_io_min(limits, 0);
- blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- if (pool->pf.discard_enabled)
- set_discard_limits(pool, limits);
-}
-
-static struct target_type pool_target = {
- .name = "thin-pool",
- .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
- DM_TARGET_IMMUTABLE,
- .version = {1, 1, 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;
-
- 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;
- }
-
- 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);
-
- 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;
- }
-
- ti->split_io = tc->pool->sectors_per_block;
- ti->num_flush_requests = 1;
-
- /* In case the pool supports discards, pass them on. */
- if (tc->pool->pf.discard_enabled) {
- ti->discards_supported = 1;
- ti->num_discard_requests = 1;
- }
-
- dm_put(pool_md);
-
- mutex_unlock(&dm_thin_pool_table.mutex);
-
- return 0;
-
-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,
- union map_info *map_context)
-{
- bio->bi_sector = dm_target_offset(ti, bio->bi_sector);
-
- return thin_bio_map(ti, bio, map_context);
-}
-
-static int thin_endio(struct dm_target *ti,
- struct bio *bio, int err,
- union map_info *map_context)
-{
- unsigned long flags;
- struct endio_hook *h = map_context->ptr;
- struct list_head work;
- struct new_mapping *m, *tmp;
- struct pool *pool = h->tc->pool;
-
- if (h->shared_read_entry) {
- INIT_LIST_HEAD(&work);
- ds_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 = 1;
- __maybe_add_mapping(m);
- }
- spin_unlock_irqrestore(&pool->lock, flags);
- }
-
- if (h->all_io_entry) {
- INIT_LIST_HEAD(&work);
- ds_dec(h->all_io_entry, &work);
- spin_lock_irqsave(&pool->lock, flags);
- list_for_each_entry_safe(m, tmp, &work, list)
- list_add(&m->list, &pool->prepared_discards);
- spin_unlock_irqrestore(&pool->lock, flags);
- }
-
- mempool_free(h, pool->endio_hook_pool);
-
- return 0;
-}
-
-static void thin_postsuspend(struct dm_target *ti)
-{
- if (dm_noflush_suspending(ti))
- requeue_io((struct thin_c *)ti->private);
-}
-
-/*
- * <nr mapped sectors> <highest mapped sector>
- */
-static int thin_status(struct dm_target *ti, status_type_t type,
- 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 (!tc->td)
- DMEMIT("-");
- else {
- switch (type) {
- case STATUSTYPE_INFO:
- r = dm_thin_get_mapped_count(tc->td, &mapped);
- if (r)
- return r;
-
- r = dm_thin_get_highest_mapped_block(tc->td, &highest);
- if (r < 0)
- return r;
-
- 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 0;
-}
-
-static int thin_iterate_devices(struct dm_target *ti,
- iterate_devices_callout_fn fn, void *data)
-{
- dm_block_t blocks;
- struct thin_c *tc = ti->private;
-
- /*
- * 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 (!tc->pool->ti)
- return 0; /* nothing is bound */
-
- blocks = tc->pool->ti->len >> tc->pool->block_shift;
- if (blocks)
- return fn(ti, tc->pool_dev, 0, tc->pool->sectors_per_block * blocks, data);
-
- return 0;
-}
-
-static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
-{
- struct thin_c *tc = ti->private;
- struct pool *pool = tc->pool;
-
- blk_limits_io_min(limits, 0);
- blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- set_discard_limits(pool, limits);
-}
-
-static struct target_type thin_target = {
- .name = "thin",
- .version = {1, 1, 0},
- .module = THIS_MODULE,
- .ctr = thin_ctr,
- .dtr = thin_dtr,
- .map = thin_map,
- .end_io = thin_endio,
- .postsuspend = thin_postsuspend,
- .status = thin_status,
- .iterate_devices = thin_iterate_devices,
- .io_hints = thin_io_hints,
-};
-
-/*----------------------------------------------------------------*/
-
-static int __init dm_thin_init(void)
-{
- int r;
-
- pool_table_init();
-
- r = dm_register_target(&thin_target);
- if (r)
- return r;
-
- r = dm_register_target(&pool_target);
- if (r)
- dm_unregister_target(&thin_target);
-
- return r;
-}
-
-static void dm_thin_exit(void)
-{
- dm_unregister_target(&thin_target);
- dm_unregister_target(&pool_target);
-}
-
-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");
generated by cgit (git 2.34.1) at 2025-07-08 07:49:43 +0000