Merge tag 'xfs-4.15-fixes-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "Here are some XFS fixes for 4.15-rc5. Apologies for the unusually
  large number of patches this late, but I wanted to make sure the
  corruption fixes were really ready to go.

  Changes since last update:

   - Fix a locking problem during xattr block conversion that could lead
     to the log checkpointing thread to try to write an incomplete
     buffer to disk, which leads to a corruption shutdown

   - Fix a null pointer dereference when removing delayed allocation
     extents

   - Remove post-eof speculative allocations when reflinking a block
     past current inode size so that we don't just leave them there and
     assert on inode reclaim

   - Relax an assert which didn't accurately reflect the way locking
     works and would trigger under heavy io load

   - Avoid infinite loop when cancelling copy on write extents after a
     writeback failure

   - Try to avoid copy on write transaction reservation overflows when
     remapping after a successful write

   - Fix various problems with the copy-on-write reservation automatic
     garbage collection not being cleaned up properly during a ro
     remount

   - Fix problems with rmap log items being processed in the wrong
     order, leading to corruption shutdowns

   - Fix problems with EFI recovery wherein the "remove any rmapping if
     present" mechanism wasn't actually doing anything, which would lead
     to corruption problems later when the extent is reallocated,
     leading to multiple rmaps for the same extent"

* tag 'xfs-4.15-fixes-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: only skip rmap owner checks for unknown-owner rmap removal
  xfs: always honor OWN_UNKNOWN rmap removal requests
  xfs: queue deferred rmap ops for cow staging extent alloc/free in the right order
  xfs: set cowblocks tag for direct cow writes too
  xfs: remove leftover CoW reservations when remounting ro
  xfs: don't be so eager to clear the cowblocks tag on truncate
  xfs: track cowblocks separately in i_flags
  xfs: allow CoW remap transactions to use reserve blocks
  xfs: avoid infinite loop when cancelling CoW blocks after writeback failure
  xfs: relax is_reflink_inode assert in xfs_reflink_find_cow_mapping
  xfs: remove dest file's post-eof preallocations before reflinking
  xfs: move xfs_iext_insert tracepoint to report useful information
  xfs: account for null transactions in bunmapi
  xfs: hold xfs_buf locked between shortform->leaf conversion and the addition of an attribute
  xfs: add the ability to join a held buffer to a defer_ops

diff --cc fs/xfs/xfs_super.c
index 5122d3021117f00e20d6dd1e195c28666cc71076,2db6a40a96bd89b35e6896d397a731d1434de150..1dacccc367f81725a678ea3a6ed50528a731920d
--- 1/fs/xfs/xfs_super.c
--- 2/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@@ -1368,7 -1369,15 +1369,15 @@@ xfs_fs_remount
        }
  
        /* rw -> ro */
 -      if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) {
 +      if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & SB_RDONLY)) {
+               /* Get rid of any leftover CoW reservations... */
+               cancel_delayed_work_sync(&mp->m_cowblocks_work);
+               error = xfs_icache_free_cowblocks(mp, NULL);
+               if (error) {
+                       xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+                       return error;
+               }
+ 
                /* Free the per-AG metadata reservation pool. */
                error = xfs_fs_unreserve_ag_blocks(mp);
                if (error) {