diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 406c33876605f617e856ad832a788c2de91d0de4..9f6f342900c91470d8eac0fa20bf3b7c80fe9da6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -767,7 +767,6 @@ struct btrfs_space_info { struct list_head block_groups[BTRFS_NR_RAID_TYPES]; spinlock_t lock; struct rw_semaphore groups_sem; - atomic_t caching_threads; wait_queue_head_t wait; }; @@ -828,6 +827,7 @@ struct btrfs_caching_control { struct list_head list; struct mutex mutex; wait_queue_head_t wait; + struct btrfs_work work; struct btrfs_block_group_cache *block_group; u64 progress; atomic_t count; @@ -1036,6 +1036,8 @@ struct btrfs_fs_info { struct btrfs_workers endio_write_workers; struct btrfs_workers endio_freespace_worker; struct btrfs_workers submit_workers; + struct btrfs_workers caching_workers; + /* * fixup workers take dirty pages that didn't properly go through * the cow mechanism and make them safe to write. It happens diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 1ac8db5dc0a31b9a742099956b121cd75ba0a1a6..234a08404fc210eac38cacb5087ad06339360703 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1807,6 +1807,9 @@ struct btrfs_root *open_ctree(struct super_block *sb, fs_info->thread_pool_size), &fs_info->generic_worker); + btrfs_init_workers(&fs_info->caching_workers, "cache", + 2, &fs_info->generic_worker); + /* a higher idle thresh on the submit workers makes it much more * likely that bios will be send down in a sane order to the * devices @@ -1860,6 +1863,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, btrfs_start_workers(&fs_info->endio_write_workers, 1); btrfs_start_workers(&fs_info->endio_freespace_worker, 1); btrfs_start_workers(&fs_info->delayed_workers, 1); + btrfs_start_workers(&fs_info->caching_workers, 1); fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super); fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages, @@ -2117,6 +2121,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, btrfs_stop_workers(&fs_info->endio_freespace_worker); btrfs_stop_workers(&fs_info->submit_workers); btrfs_stop_workers(&fs_info->delayed_workers); + btrfs_stop_workers(&fs_info->caching_workers); fail_alloc: kfree(fs_info->delayed_root); fail_iput: @@ -2584,6 +2589,7 @@ int close_ctree(struct btrfs_root *root) btrfs_stop_workers(&fs_info->endio_freespace_worker); btrfs_stop_workers(&fs_info->submit_workers); btrfs_stop_workers(&fs_info->delayed_workers); + btrfs_stop_workers(&fs_info->caching_workers); btrfs_close_devices(fs_info->fs_devices); btrfs_mapping_tree_free(&fs_info->mapping_tree); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 340c14715091a94c5b1d0e4358d9ec74571cccde..5ab31f70ff5b08dd568db35681c7e796c4f6e266 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -320,12 +320,12 @@ static u64 add_new_free_space(struct btrfs_block_group_cache *block_group, return total_added; } -static int caching_kthread(void *data) +static noinline void caching_thread(struct btrfs_work *work) { - struct btrfs_block_group_cache *block_group = data; - struct btrfs_fs_info *fs_info = block_group->fs_info; - struct btrfs_caching_control *caching_ctl = block_group->caching_ctl; - struct btrfs_root *extent_root = fs_info->extent_root; + struct btrfs_block_group_cache *block_group; + struct btrfs_fs_info *fs_info; + struct btrfs_caching_control *caching_ctl; + struct btrfs_root *extent_root; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key key; @@ -334,9 +334,14 @@ static int caching_kthread(void *data) u32 nritems; int ret = 0; + caching_ctl = container_of(work, struct btrfs_caching_control, work); + block_group = caching_ctl->block_group; + fs_info = block_group->fs_info; + extent_root = fs_info->extent_root; + path = btrfs_alloc_path(); if (!path) - return -ENOMEM; + goto out; last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); @@ -433,13 +438,11 @@ static int caching_kthread(void *data) free_excluded_extents(extent_root, block_group); mutex_unlock(&caching_ctl->mutex); +out: wake_up(&caching_ctl->wait); put_caching_control(caching_ctl); - atomic_dec(&block_group->space_info->caching_threads); btrfs_put_block_group(block_group); - - return 0; } static int cache_block_group(struct btrfs_block_group_cache *cache, @@ -449,7 +452,6 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, { struct btrfs_fs_info *fs_info = cache->fs_info; struct btrfs_caching_control *caching_ctl; - struct task_struct *tsk; int ret = 0; smp_mb(); @@ -501,6 +503,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, caching_ctl->progress = cache->key.objectid; /* one for caching kthread, one for caching block group list */ atomic_set(&caching_ctl->count, 2); + caching_ctl->work.func = caching_thread; spin_lock(&cache->lock); if (cache->cached != BTRFS_CACHE_NO) { @@ -516,16 +519,9 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); up_write(&fs_info->extent_commit_sem); - atomic_inc(&cache->space_info->caching_threads); btrfs_get_block_group(cache); - tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n", - cache->key.objectid); - if (IS_ERR(tsk)) { - ret = PTR_ERR(tsk); - printk(KERN_ERR "error running thread %d\n", ret); - BUG(); - } + btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work); return ret; } @@ -2936,7 +2932,6 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, init_waitqueue_head(&found->wait); *space_info = found; list_add_rcu(&found->list, &info->space_info); - atomic_set(&found->caching_threads, 0); return 0; } @@ -4997,14 +4992,10 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans, } /* - * We only want to start kthread caching if we are at - * the point where we will wait for caching to make - * progress, or if our ideal search is over and we've - * found somebody to start caching. + * The caching workers are limited to 2 threads, so we + * can queue as much work as we care to. */ - if (loop > LOOP_CACHING_NOWAIT || - (loop > LOOP_FIND_IDEAL && - atomic_read(&space_info->caching_threads) < 2)) { + if (loop > LOOP_FIND_IDEAL) { ret = cache_block_group(block_group, trans, orig_root, 0); BUG_ON(ret); @@ -5226,8 +5217,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans, if (loop == LOOP_FIND_IDEAL && found_uncached_bg) { found_uncached_bg = false; loop++; - if (!ideal_cache_percent && - atomic_read(&space_info->caching_threads)) + if (!ideal_cache_percent) goto search; /*