[v5,10/19] vfs: fix symlinkat to retry on ESTALE errors

Commit Message

Jeff Layton Aug. 8, 2012, 1:21 p.m. UTC

Signed-off-by: Jeff Layton <[e-mail]>
---
 fs/namei.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

Patch

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;
 }