mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 02:17:36 -04:00
Code Issues Packages Projects Releases Wiki Activity

btrfs: fix reloc root cleanup in merge_reloc_roots()

Browse Source 
If the root we got has zero root refs in its root item, we are resetting
the root's ->reloc_root without using barriers like we do everywhere else.
Sashiko complained about this while reviewing another patch, and it's
correct (see the Link tag below).

Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless
the root points to the reloc root we have.

Fix this by using clear_reloc_root(), which issues the memory barrier
after setting the root's ->reloc_root to NULL and before clearing the bit
BTRFS_ROOT_DEAD_RELOC_TREE from the root.

Link: https://sashiko.dev/#/patchset/cf84f1a217c719e25b6b69e4298dd7afd36c9427.1781194426.git.fdmanana%40suse.com
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Filipe Manana
2026-06-12 11:52:55 +01:00
committed by David Sterba
parent 83201804ef
commit b78fe9563e
1 changed files with 2 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
fs/btrfs/relocation.c
View File

@@ -1948,11 +1948,10 @@ void merge_reloc_roots(struct reloc_control *rc)
} else {
if (!IS_ERR(root)) {
if (root->reloc_root == reloc_root) {
root->reloc_root = NULL;
clear_reloc_root(root);
/* Drop the ref for root->reloc_root. */
btrfs_put_root(reloc_root);
}
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE,
&root->state);
btrfs_put_root(root);
}