tree 54a0a2b42e3a6ce7dfe097d0240ed27e8d50ce2a
parent b2acdddfad13c38a1e8b927d83c3cf321f63601a
author Josef Bacik <jbacik@fb.com> 1445540709 -0400
committer David Sterba <dsterba@suse.com> 1452173218 +0100

Btrfs: igrab inode in writepage

We hit this panic on a few of our boxes this week where we have an
ordered_extent with an NULL inode.  We do an igrab() of the inode in writepages,
but weren't doing it in writepage which can be called directly from the VM on
dirty pages.  If the inode has been unlinked then we could have I_FREEING set
which means igrab() would return NULL and we get this panic.  Fix this by trying
to igrab in btrfs_writepage, and if it returns NULL then just redirty the page
and return AOP_WRITEPAGE_ACTIVATE; so the VM knows it wasn't successful.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>