btrfs: Handle btrfs_set_extent_delalloc failure in fixup worker

BugLink: http://bugs.launchpad.net/bugs/1751064
commit f3038ee3a3f1017a1cbe9907e31fa12d366c5dcb upstream.

This function was introduced by 247e743cbe6e ("Btrfs: Use async helpers
to deal with pages that have been improperly dirtied") and it didn't do
any error handling then. This function might very well fail in ENOMEM
situation, yet it's not handled, this could lead to inconsistent state.
So let's handle the failure by setting the mapping error bit.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e1a7f3cb5be940561af3ec855b6657c3fce7c850..0f57602092cfe01a9f456400b0961c8684ec7182 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2098,8 +2098,15 @@ again:
                goto out;
         }
 
-       btrfs_set_extent_delalloc(inode, page_start, page_end, 0, &cached_state,
-                                 0);
+       ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
+                                       &cached_state, 0);
+       if (ret) {
+               mapping_set_error(page->mapping, ret);
+               end_extent_writepage(page, ret, page_start, page_end);
+               ClearPageChecked(page);
+               goto out;
+       }
+
        ClearPageChecked(page);
        set_page_dirty(page);
        btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);