From: Benjamin Coddington <bcodding@redhat.com>
To: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH v2] NFS: Don't skip lookup when holding a delegation
Date: Thu, 19 Sep 2019 10:49:00 -0400 [thread overview]
Message-ID: <77be993185fa7f114f6856f74f2f7affb5bd411d.1568904510.git.bcodding@redhat.com> (raw)
If we skip lookup revalidation while holding a delegation, we might miss
that the file has changed directories on the server. The directory's
change attribute should still be checked against the dentry's d_time to
perform a complete revalidation.
V2 - Add some commentary as suggested-by J. Bruce Fields.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
fs/nfs/dir.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 0adfd8840110..8723e82f5c9d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1197,12 +1197,20 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
goto out_bad;
}
- if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
- return nfs_lookup_revalidate_delegated(dir, dentry, inode);
-
/* Force a full look up iff the parent directory has changed */
if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) &&
nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
+
+ /*
+ * Note that the file can't move while we hold a
+ * delegation. But this dentry could have been cached
+ * before we got a delegation. So it's only safe to
+ * skip revalidation when the parent directory is
+ * unchanged:
+ */
+ if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
+ return nfs_lookup_revalidate_delegated(dir, dentry, inode);
+
error = nfs_lookup_verify_inode(inode, flags);
if (error) {
if (error == -ESTALE)
@@ -1635,9 +1643,6 @@ nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
if (inode == NULL)
goto full_reval;
- if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
- return nfs_lookup_revalidate_delegated(dir, dentry, inode);
-
/* NFS only supports OPEN on regular files */
if (!S_ISREG(inode->i_mode))
goto full_reval;
--
2.20.1
next reply other threads:[~2019-09-19 14:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 14:49 Benjamin Coddington [this message]
2020-01-16 15:19 ` [PATCH v2] NFS: Don't skip lookup when holding a delegation Benjamin Coddington
2020-01-16 16:02 ` Trond Myklebust
2020-01-16 16:32 ` Benjamin Coddington
2020-01-16 16:44 ` Trond Myklebust
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