[PATCH] NFS: Fix inverted cross-directory rename check

[Avi Weiss]

nfs_rename_is_unsafe_cross_dir() returns false for cross-directory
renames, causing nfs_rename() to skip nfs_sync_inode() even when
filehandles may expire on rename. Same-directory renames may instead
trigger unnecessary synchronization.

Current condition directly contradicts the function name/comments.

Return false for same-directory renames so cross-directory renames
reach the existing filehandle-volatility check. Keep the conservative
fallback unchanged..

Fixes: dcd21b609d4ab ("NFS: Avoid flushing data while holding directory locks in nfs_rename()")
Signed-off-by: Avi Weiss <thnkslprpt@xxxxxxxxx>
---
 fs/nfs/dir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 49394123bd09..aff6b9d45523 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2740,7 +2740,7 @@ static bool nfs_rename_is_unsafe_cross_dir(struct dentry *old_dentry,
 {
 	struct nfs_server *server = NFS_SB(old_dentry->d_sb);
 
-	if (old_dentry->d_parent != new_dentry->d_parent)
+	if (old_dentry->d_parent == new_dentry->d_parent)
 		return false;
 	if (server->fh_expire_type & NFS_FH_RENAME_UNSAFE)
 		return !(server->fh_expire_type & NFS_FH_NOEXPIRE_WITH_OPEN);

base-commit: 32c52ec87d6245ee2d12ed5dd509e40062939b50
-- 
2.43.0