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[1/3] NFS: Optimise away the close-to-open GETATTR when we have NFSv4 OPEN

Message ID 20180510192858.18539-1-trond.myklebust@hammerspace.com (mailing list archive)
State New, archived
Headers show

Commit Message

Trond Myklebust May 10, 2018, 7:28 p.m. UTC
NFSv4 should not need to perform an extra close-to-open GETATTR as part
of the process of looking up a regular file, since the OPEN call will
do that for us.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 73f8b43d988c..4a73bd8b4517 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1012,13 +1012,25 @@  int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
 
 	if (IS_AUTOMOUNT(inode))
 		return 0;
+
+	if (flags & LOOKUP_OPEN) {
+		switch (inode->i_mode & S_IFMT) {
+		case S_IFREG:
+			/* A NFSv4 OPEN will revalidate later */
+			if (server->caps & NFS_CAP_ATOMIC_OPEN)
+				goto out;
+			/* Fallthrough */
+		case S_IFDIR:
+			if (server->flags & NFS_MOUNT_NOCTO)
+				break;
+			/* NFS close-to-open cache consistency validation */
+			goto out_force;
+		}
+	}
+
 	/* VFS wants an on-the-wire revalidation */
 	if (flags & LOOKUP_REVAL)
 		goto out_force;
-	/* This is an open(2) */
-	if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
-	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
-		goto out_force;
 out:
 	return (inode->i_nlink == 0) ? -ENOENT : 0;
 out_force: