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| author | Filipe Manana <fdmanana@suse.com> | 2022-11-21 13:23:24 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-12-05 20:00:59 +0300 |
| commit | 3eb423442483d454937cdc8853e58c399ffe5514 (patch) | |
| tree | dfadb5d97014389be53c73b101b34a069dcdcf3a /fs/btrfs | |
| parent | 3a8d1db341b93e65fa76051ab833b3640842b6eb (diff) | |
| download | linux-3eb423442483d454937cdc8853e58c399ffe5514.tar.xz | |
btrfs: remove outdated logic from overwrite_item() and add assertion
As of commit 193df6245704 ("btrfs: search for last logged dir index if
it's not cached in the inode"), the overwrite_item() function is always
called for a root that is from a fs/subvolume tree. In other words, now
it's only used during log replay to modify a fs/subvolume tree. Therefore
we can remove the logic that checks if we are dealing with a log tree at
overwrite_item().
So remove that logic, replacing it with an assertion and document that if
we ever need to support a log root there, we will need to clone the leaf
from the fs/subvolume tree and then release it before modifying the log
tree, which is needed to avoid a potential deadlock, similar to the one
recently fixed by a patch with the subject:
"btrfs: do not modify log tree while holding a leaf from fs tree locked"
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/tree-log.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index bcc8717f51fd..a3c43f0b1c95 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -391,11 +391,16 @@ static int overwrite_item(struct btrfs_trans_handle *trans, int save_old_i_size = 0; unsigned long src_ptr; unsigned long dst_ptr; - int overwrite_root = 0; bool inode_item = key->type == BTRFS_INODE_ITEM_KEY; - if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) - overwrite_root = 1; + /* + * This is only used during log replay, so the root is always from a + * fs/subvolume tree. In case we ever need to support a log root, then + * we'll have to clone the leaf in the path, release the path and use + * the leaf before writing into the log tree. See the comments at + * copy_items() for more details. + */ + ASSERT(root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID); item_size = btrfs_item_size(eb, slot); src_ptr = btrfs_item_ptr_offset(eb, slot); @@ -548,8 +553,7 @@ insert: goto no_copy; } - if (overwrite_root && - S_ISDIR(btrfs_inode_mode(eb, src_item)) && + if (S_ISDIR(btrfs_inode_mode(eb, src_item)) && S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) { save_old_i_size = 1; saved_i_size = btrfs_inode_size(path->nodes[0], |