udf: Properly detect stale inodes

NFS can easily ask for inodes that are already deleted. Currently UDF
happily returns such inodes which is a bug. Return -ESTALE if
udf_read_inode() is asked to read deleted inode.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 788fc58ea78e..3a44d9187aad 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1435,8 +1435,10 @@ reread:
         read_unlock(&sbi->s_cred_lock);
 
         link_count = le16_to_cpu(fe->fileLinkCount);
-        if (!link_count)
-                link_count = 1;
+        if (!link_count) {
+                ret = -ESTALE;
+                goto out;
+        }
         set_nlink(inode, link_count);
 
         inode->i_size = le64_to_cpu(fe->informationLength);