iget: introduce a function to register iget failure

Introduce a function to register failure in an inode construction path.  This
includes marking the inode under construction as bad, unlocking it and
releasing it.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 5 deletions

diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 0f33c77bc14b..fbd3815a5f57 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -184,11 +184,19 @@ just takes the superblock and inode number as arguments and does the
 test and set for you.
 
 e.g.
-       inode = iget_locked(sb, ino);
-       if (inode->i_state & I_NEW) {
-               read_inode_from_disk(inode);
-               unlock_new_inode(inode);
-       }
+        inode = iget_locked(sb, ino);
+        if (inode->i_state & I_NEW) {
+                err = read_inode_from_disk(inode);
+                if (err < 0) {
+                        iget_failed(inode);
+                        return err;
+                }
+                unlock_new_inode(inode);
+        }
+
+Note that if the process of setting up a new inode fails, then iget_failed()
+should be called on the inode to render it dead, and an appropriate error
+should be passed back to the caller.
 
 ---
 [recommended]