linux-kernel - [PATCH v8 02/32] vfs: make fstatat retry on ESTALE errors from getattr call

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Date:	Sat, 27 Oct 2012 08:33:09 -0400
From:	Jeff Layton <jlayton@...hat.com>
To:	viro@...iv.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org, michael.brantley@...haw.com,
	hch@...radead.org, miklos@...redi.hu, pstaubach@...grid.com
Subject: [PATCH v8 02/32] vfs: make fstatat retry on ESTALE errors from getattr call

Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
 fs/stat.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fs/stat.c b/fs/stat.c
index eae4946..c97a17e 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -74,7 +74,8 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
 {
 	struct path path;
 	int error = -EINVAL;
-	int lookup_flags = 0;
+	unsigned int try = 0;
+	unsigned int lookup_flags = 0;
 
 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
 		      AT_EMPTY_PATH)) != 0)
@@ -85,12 +86,15 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
 	if (flag & AT_EMPTY_PATH)
 		lookup_flags |= LOOKUP_EMPTY;
 
-	error = user_path_at(dfd, filename, lookup_flags, &path);
-	if (error)
-		goto out;
+	do {
+		error = user_path_at(dfd, filename, lookup_flags, &path);
+		if (error)
+			break;
 
-	error = vfs_getattr(path.mnt, path.dentry, stat);
-	path_put(&path);
+		error = vfs_getattr(path.mnt, path.dentry, stat);
+		path_put(&path);
+		lookup_flags |= LOOKUP_REVAL;
+	} while (retry_estale(error, try++));
 out:
 	return error;
 }
-- 
1.7.11.7

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