linux-kernel - [PATCH v5 10/19] vfs: fix symlinkat to retry on ESTALE errors

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Date:	Wed,  8 Aug 2012 09:21:33 -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 v5 10/19] vfs: fix symlinkat to retry on ESTALE errors

Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
 fs/namei.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 9fd5163..9986117 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3468,24 +3468,34 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
 		int, newdfd, const char __user *, newname)
 {
 	int error;
-	char *from;
+	char *from, *to;
 	struct dentry *dentry;
 	struct path path;
+	unsigned int try = 0;
 
 	from = getname(oldname);
 	if (IS_ERR(from))
 		return PTR_ERR(from);
 
-	dentry = user_path_create(newdfd, newname, &path, 0);
-	error = PTR_ERR(dentry);
-	if (IS_ERR(dentry))
-		goto out_putname;
+	to = getname(newname);
+	if (IS_ERR(to)) {
+		putname(from);
+		return PTR_ERR(to);
+	}
 
-	error = security_path_symlink(&path, dentry, from);
-	if (!error)
-		error = vfs_symlink(path.dentry->d_inode, dentry, from);
-	done_path_create(&path, dentry);
-out_putname:
+	do {
+		dentry = kern_path_create(newdfd, to, &path, 0, try);
+		if (IS_ERR(dentry)) {
+			error = PTR_ERR(dentry);
+			break;
+		}
+
+		error = security_path_symlink(&path, dentry, from);
+		if (!error)
+			error = vfs_symlink(path.dentry->d_inode, dentry, from);
+		done_path_create(&path, dentry);
+	} while (retry_estale(error, try++));
+	putname(to);
 	putname(from);
 	return error;
 }
-- 
1.7.11.2

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