diff mbox series

[5/5] NFS: Fix dentry verifier races

Message ID 20210929134944.632844-5-trondmy@kernel.org (mailing list archive)
State New, archived
Headers show
Series [1/5] NFS: Don't set NFS_INO_DATA_INVAL_DEFER and NFS_INO_INVALID_DATA | expand

Commit Message

Trond Myklebust Sept. 29, 2021, 1:49 p.m. UTC 
From: Trond Myklebust <trond.myklebust@hammerspace.com>

If the directory changed while we were revalidating the dentry, then
don't update the dentry verifier. There is no value in setting the
verifier to an older value, and we could end up overwriting a more up to
date verifier from a parallel revalidation.

Fixes: efeda80da38d ("NFSv4: Fix revalidation of dentries with delegations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 358033aea235..033e9b145627 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1276,13 +1276,12 @@  static bool nfs_verifier_is_delegated(struct dentry *dentry)
 static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf)
 {
 	struct inode *inode = d_inode(dentry);
+	struct inode *dir = d_inode(dentry->d_parent);
 
-	if (!nfs_verifier_is_delegated(dentry) &&
-	    !nfs_verify_change_attribute(d_inode(dentry->d_parent), verf))
-		goto out;
+	if (!nfs_verify_change_attribute(dir, verf))
+		return;
 	if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
 		nfs_set_verifier_delegated(&verf);
-out:
 	dentry->d_time = verf;
 }