diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/ctree.h | 1 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 1 | ||||
| -rw-r--r-- | fs/btrfs/extent-tree.c | 21 |
3 files changed, 22 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 54a66fa6beb1..d3562dd43c66 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1744,6 +1744,7 @@ struct btrfs_fs_info { spinlock_t unused_bgs_lock; struct list_head unused_bgs; + struct mutex unused_bg_unpin_mutex; /* For btrfs to record security options */ struct security_mnt_opts security_opts; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 263d1471d01a..41b320e235d7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2242,6 +2242,7 @@ int open_ctree(struct super_block *sb, spin_lock_init(&fs_info->qgroup_op_lock); spin_lock_init(&fs_info->buffer_lock); spin_lock_init(&fs_info->unused_bgs_lock); + mutex_init(&fs_info->unused_bg_unpin_mutex); rwlock_init(&fs_info->tree_mod_log_lock); mutex_init(&fs_info->reloc_mutex); mutex_init(&fs_info->delalloc_root_mutex); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 53294da0749d..857a859948a3 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5735,10 +5735,13 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, unpin = &fs_info->freed_extents[0]; while (1) { + mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY, NULL); - if (ret) + if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); break; + } if (btrfs_test_opt(root, DISCARD)) ret = btrfs_discard_extent(root, start, @@ -5746,6 +5749,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, clear_extent_dirty(unpin, start, end, GFP_NOFS); unpin_extent_range(root, start, end, true); + mutex_unlock(&fs_info->unused_bg_unpin_mutex); cond_resched(); } @@ -9561,18 +9565,33 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) */ start = block_group->key.objectid; end = start + block_group->key.offset - 1; + /* + * Hold the unused_bg_unpin_mutex lock to avoid racing with + * btrfs_finish_extent_commit(). If we are at transaction N, + * another task might be running finish_extent_commit() for the + * previous transaction N - 1, and have seen a range belonging + * to the block group in freed_extents[] before we were able to + * clear the whole block group range from freed_extents[]. This + * means that task can lookup for the block group after we + * unpinned it from freed_extents[] and removed it, leading to + * a BUG_ON() at btrfs_unpin_extent_range(). + */ + mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = clear_extent_bits(&fs_info->freed_extents[0], start, end, EXTENT_DIRTY, GFP_NOFS); if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); btrfs_set_block_group_rw(root, block_group); goto end_trans; } ret = clear_extent_bits(&fs_info->freed_extents[1], start, end, EXTENT_DIRTY, GFP_NOFS); if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); btrfs_set_block_group_rw(root, block_group); goto end_trans; } + mutex_unlock(&fs_info->unused_bg_unpin_mutex); /* Reset pinned so btrfs_put_block_group doesn't complain */ block_group->pinned = 0; |