[PATCH v7 23/49] vfs: fix readlinkat to retry on ESTALE

Jeff Layton
2012-10-02T00:17:38Z

fs/stat.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/stat.c b/fs/stat.c
index 7f1602a..ede71cb 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -300,14 +300,21 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
struct path path;
int error;
int empty = 0;
+ unsigned int try = 0;
+ unsigned int lookup_flags = LOOKUP_EMPTY;

if (bufsiz <= 0)
return -EINVAL;

- error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty);
- if (!error) {
- struct inode *inode = path.dentry->d_inode;
+ do {
+ struct inode *inode;
+
+ error = user_path_at_empty(dfd, pathname, lookup_flags,
+ &path, &empty);
+ if (error)
+ break;

+ inode = path.dentry->d_inode;
error = empty ? -ENOENT : -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
@@ -318,7 +325,8 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
}
}
path_put(&path);
- }
+ lookup_flags |= LOOKUP_REVAL;
+ } while (retry_estale(error, try++));
return error;
}

--
1.7.11.4