diff options
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/dm-cache-target.c | 28 | ||||
-rw-r--r-- | drivers/md/dm-clone-target.c | 4 | ||||
-rw-r--r-- | drivers/md/dm-snap.c | 94 | ||||
-rw-r--r-- | drivers/md/raid0.c | 2 |
4 files changed, 82 insertions, 46 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index d249cf8ac277..8346e6d1816c 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -542,7 +542,7 @@ static void wake_migration_worker(struct cache *cache) static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache) { - return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOWAIT); + return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOIO); } static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell) @@ -554,9 +554,7 @@ static struct dm_cache_migration *alloc_migration(struct cache *cache) { struct dm_cache_migration *mg; - mg = mempool_alloc(&cache->migration_pool, GFP_NOWAIT); - if (!mg) - return NULL; + mg = mempool_alloc(&cache->migration_pool, GFP_NOIO); memset(mg, 0, sizeof(*mg)); @@ -664,10 +662,6 @@ static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bi struct dm_bio_prison_cell_v2 *cell_prealloc, *cell; cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */ - if (!cell_prealloc) { - defer_bio(cache, bio); - return false; - } build_key(oblock, end, &key); r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell); @@ -1493,11 +1487,6 @@ static int mg_lock_writes(struct dm_cache_migration *mg) struct dm_bio_prison_cell_v2 *prealloc; prealloc = alloc_prison_cell(cache); - if (!prealloc) { - DMERR_LIMIT("%s: alloc_prison_cell failed", cache_device_name(cache)); - mg_complete(mg, false); - return -ENOMEM; - } /* * Prevent writes to the block, but allow reads to continue. @@ -1535,11 +1524,6 @@ static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio } mg = alloc_migration(cache); - if (!mg) { - policy_complete_background_work(cache->policy, op, false); - background_work_end(cache); - return -ENOMEM; - } mg->op = op; mg->overwrite_bio = bio; @@ -1628,10 +1612,6 @@ static int invalidate_lock(struct dm_cache_migration *mg) struct dm_bio_prison_cell_v2 *prealloc; prealloc = alloc_prison_cell(cache); - if (!prealloc) { - invalidate_complete(mg, false); - return -ENOMEM; - } build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key); r = dm_cell_lock_v2(cache->prison, &key, @@ -1669,10 +1649,6 @@ static int invalidate_start(struct cache *cache, dm_cblock_t cblock, return -EPERM; mg = alloc_migration(cache); - if (!mg) { - background_work_end(cache); - return -ENOMEM; - } mg->overwrite_bio = bio; mg->invalidate_cblock = cblock; diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c index cd6f9e9fc98e..4ca8f1977222 100644 --- a/drivers/md/dm-clone-target.c +++ b/drivers/md/dm-clone-target.c @@ -591,8 +591,8 @@ static struct hash_table_bucket *get_hash_table_bucket(struct clone *clone, * * NOTE: Must be called with the bucket lock held */ -struct dm_clone_region_hydration *__hash_find(struct hash_table_bucket *bucket, - unsigned long region_nr) +static struct dm_clone_region_hydration *__hash_find(struct hash_table_bucket *bucket, + unsigned long region_nr) { struct dm_clone_region_hydration *hd; diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index f150f5c5492b..4fb1a40e68a0 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -18,7 +18,6 @@ #include <linux/vmalloc.h> #include <linux/log2.h> #include <linux/dm-kcopyd.h> -#include <linux/semaphore.h> #include "dm.h" @@ -107,8 +106,8 @@ struct dm_snapshot { /* The on disk metadata handler */ struct dm_exception_store *store; - /* Maximum number of in-flight COW jobs. */ - struct semaphore cow_count; + unsigned in_progress; + struct wait_queue_head in_progress_wait; struct dm_kcopyd_client *kcopyd_client; @@ -162,8 +161,8 @@ struct dm_snapshot { */ #define DEFAULT_COW_THRESHOLD 2048 -static int cow_threshold = DEFAULT_COW_THRESHOLD; -module_param_named(snapshot_cow_threshold, cow_threshold, int, 0644); +static unsigned cow_threshold = DEFAULT_COW_THRESHOLD; +module_param_named(snapshot_cow_threshold, cow_threshold, uint, 0644); MODULE_PARM_DESC(snapshot_cow_threshold, "Maximum number of chunks being copied on write"); DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle, @@ -1327,7 +1326,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto bad_hash_tables; } - sema_init(&s->cow_count, (cow_threshold > 0) ? cow_threshold : INT_MAX); + init_waitqueue_head(&s->in_progress_wait); s->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle); if (IS_ERR(s->kcopyd_client)) { @@ -1509,9 +1508,56 @@ static void snapshot_dtr(struct dm_target *ti) dm_put_device(ti, s->origin); + WARN_ON(s->in_progress); + kfree(s); } +static void account_start_copy(struct dm_snapshot *s) +{ + spin_lock(&s->in_progress_wait.lock); + s->in_progress++; + spin_unlock(&s->in_progress_wait.lock); +} + +static void account_end_copy(struct dm_snapshot *s) +{ + spin_lock(&s->in_progress_wait.lock); + BUG_ON(!s->in_progress); + s->in_progress--; + if (likely(s->in_progress <= cow_threshold) && + unlikely(waitqueue_active(&s->in_progress_wait))) + wake_up_locked(&s->in_progress_wait); + spin_unlock(&s->in_progress_wait.lock); +} + +static bool wait_for_in_progress(struct dm_snapshot *s, bool unlock_origins) +{ + if (unlikely(s->in_progress > cow_threshold)) { + spin_lock(&s->in_progress_wait.lock); + if (likely(s->in_progress > cow_threshold)) { + /* + * NOTE: this throttle doesn't account for whether + * the caller is servicing an IO that will trigger a COW + * so excess throttling may result for chunks not required + * to be COW'd. But if cow_threshold was reached, extra + * throttling is unlikely to negatively impact performance. + */ + DECLARE_WAITQUEUE(wait, current); + __add_wait_queue(&s->in_progress_wait, &wait); + __set_current_state(TASK_UNINTERRUPTIBLE); + spin_unlock(&s->in_progress_wait.lock); + if (unlock_origins) + up_read(&_origins_lock); + io_schedule(); + remove_wait_queue(&s->in_progress_wait, &wait); + return false; + } + spin_unlock(&s->in_progress_wait.lock); + } + return true; +} + /* * Flush a list of buffers. */ @@ -1527,7 +1573,7 @@ static void flush_bios(struct bio *bio) } } -static int do_origin(struct dm_dev *origin, struct bio *bio); +static int do_origin(struct dm_dev *origin, struct bio *bio, bool limit); /* * Flush a list of buffers. @@ -1540,7 +1586,7 @@ static void retry_origin_bios(struct dm_snapshot *s, struct bio *bio) while (bio) { n = bio->bi_next; bio->bi_next = NULL; - r = do_origin(s->origin, bio); + r = do_origin(s->origin, bio, false); if (r == DM_MAPIO_REMAPPED) generic_make_request(bio); bio = n; @@ -1732,7 +1778,7 @@ static void copy_callback(int read_err, unsigned long write_err, void *context) rb_link_node(&pe->out_of_order_node, parent, p); rb_insert_color(&pe->out_of_order_node, &s->out_of_order_tree); } - up(&s->cow_count); + account_end_copy(s); } /* @@ -1756,7 +1802,7 @@ static void start_copy(struct dm_snap_pending_exception *pe) dest.count = src.count; /* Hand over to kcopyd */ - down(&s->cow_count); + account_start_copy(s); dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, copy_callback, pe); } @@ -1776,7 +1822,7 @@ static void start_full_bio(struct dm_snap_pending_exception *pe, pe->full_bio = bio; pe->full_bio_end_io = bio->bi_end_io; - down(&s->cow_count); + account_start_copy(s); callback_data = dm_kcopyd_prepare_callback(s->kcopyd_client, copy_callback, pe); @@ -1866,7 +1912,7 @@ static void zero_callback(int read_err, unsigned long write_err, void *context) struct bio *bio = context; struct dm_snapshot *s = bio->bi_private; - up(&s->cow_count); + account_end_copy(s); bio->bi_status = write_err ? BLK_STS_IOERR : 0; bio_endio(bio); } @@ -1880,7 +1926,7 @@ static void zero_exception(struct dm_snapshot *s, struct dm_exception *e, dest.sector = bio->bi_iter.bi_sector; dest.count = s->store->chunk_size; - down(&s->cow_count); + account_start_copy(s); WARN_ON_ONCE(bio->bi_private); bio->bi_private = s; dm_kcopyd_zero(s->kcopyd_client, 1, &dest, 0, zero_callback, bio); @@ -1916,6 +1962,11 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio) if (!s->valid) return DM_MAPIO_KILL; + if (bio_data_dir(bio) == WRITE) { + while (unlikely(!wait_for_in_progress(s, false))) + ; /* wait_for_in_progress() has slept */ + } + down_read(&s->lock); dm_exception_table_lock(&lock); @@ -2112,7 +2163,7 @@ redirect_to_origin: if (bio_data_dir(bio) == WRITE) { up_write(&s->lock); - return do_origin(s->origin, bio); + return do_origin(s->origin, bio, false); } out_unlock: @@ -2487,15 +2538,24 @@ next_snapshot: /* * Called on a write from the origin driver. */ -static int do_origin(struct dm_dev *origin, struct bio *bio) +static int do_origin(struct dm_dev *origin, struct bio *bio, bool limit) { struct origin *o; int r = DM_MAPIO_REMAPPED; +again: down_read(&_origins_lock); o = __lookup_origin(origin->bdev); - if (o) + if (o) { + if (limit) { + struct dm_snapshot *s; + list_for_each_entry(s, &o->snapshots, list) + if (unlikely(!wait_for_in_progress(s, true))) + goto again; + } + r = __origin_write(&o->snapshots, bio->bi_iter.bi_sector, bio); + } up_read(&_origins_lock); return r; @@ -2608,7 +2668,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio) dm_accept_partial_bio(bio, available_sectors); /* Only tell snapshots if this is a write */ - return do_origin(o->dev, bio); + return do_origin(o->dev, bio, true); } /* diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index f2b83bd2fee6..b7c20979bd19 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -154,7 +154,7 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) } else { pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", mdname(mddev)); - pr_err("md/raid0: please set raid.default_layout to 1 or 2\n"); + pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n"); err = -ENOTSUPP; goto abort; } |