[PATCH 2/3] xfs: truncate delalloc extents when IO fails in writeback

[Christoph Hellwig]

Btw, I can trigger the new warnings from this patch in xfsqa after
a few full XFSQA runs:

[39829.737139] Filesystem "vdb6": page discard on page c21d7480, inode
0x3f8, offset 0.
[39829.739488] Filesystem "vdb6": page discard failed delalloc mapping
lookup.
[39829.744005] Filesystem "vdb6": page discard on page c206ba80, inode
0x3f9, offset 0.
[39829.746496] Filesystem "vdb6": page discard failed delalloc mapping
lookup.
[39829.748655] Filesystem "vdb6": page discard on page c20e02a0, inode
0x3fa, offset 0.
[39829.751000] Filesystem "vdb6": page discard failed delalloc mapping
lookup.


going on for a few pages of kernel messages.