vfs: make fstatat retry on ESTALE errors from getattr call

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/stat.c b/fs/stat.c
index eae494630a36507e03defe8bdf836ee6b337b4ee..d221995278803c20f91aa089dcc9823cc3c34da8 100644 (file)
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -74,7 +74,7 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
 {
        struct path path;
        int error = -EINVAL;
 {
        struct path path;
        int error = -EINVAL;

-       int lookup_flags = 0;
+       unsigned int lookup_flags = 0;

 
        if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
                      AT_EMPTY_PATH)) != 0)
 
        if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
                      AT_EMPTY_PATH)) != 0)


@@ -84,13 +84,17 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
                lookup_flags |= LOOKUP_FOLLOW;
        if (flag & AT_EMPTY_PATH)
                lookup_flags |= LOOKUP_EMPTY;
                lookup_flags |= LOOKUP_FOLLOW;
        if (flag & AT_EMPTY_PATH)
                lookup_flags |= LOOKUP_EMPTY;

-
+retry:

        error = user_path_at(dfd, filename, lookup_flags, &path);
        if (error)
                goto out;
 
        error = vfs_getattr(path.mnt, path.dentry, stat);
        path_put(&path);
        error = user_path_at(dfd, filename, lookup_flags, &path);
        if (error)
                goto out;
 
        error = vfs_getattr(path.mnt, path.dentry, stat);
        path_put(&path);

+       if (retry_estale(error, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }

 out:
        return error;
 }
 out:
        return error;
 }