Merge tag 'xfs-for-linus-3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs fixes from Dave Chinner:
 "The fixes all address recently discovered data corruption issues.

  The original Direct IO issue was discovered by Chris Mason @ Facebook
  on a production workload which mixed buffered reads with direct reads
  and writes IO to the same file.  The fix for that exposed other issues
  with page invalidation (exposed by millions of fsx operations) failing
  due to dirty buffers beyond EOF.

  Finally, the collapse_range code could also cause problems due to
  racing writeback changing the extent map while it was being shifted
  around.  The commits for that problem are simple mitigation fixes that
  prevent the problem from occuring.  A more robust fix for 3.18 that
  addresses the underlying problem is currently being worked on by
  Brian.

  Summary of fixes:
   - a direct IO read/buffered read data corruption
   - the associated fallout from the DIO data corruption fix
   - collapse range bugs that are potential data corruption issues"

* tag 'xfs-for-linus-3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: trim eofblocks before collapse range
  xfs: xfs_file_collapse_range is delalloc challenged
  xfs: don't log inode unless extent shift makes extent modifications
  xfs: use ranged writeback and invalidation for direct IO
  xfs: don't zero partial page cache pages during O_DIRECT writes
  xfs: don't zero partial page cache pages during O_DIRECT writes
  xfs: don't dirty buffers beyond EOF

1 files changed, 20 insertions, 0 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 2f1e30d39a35..1707980f9a4b 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1470,6 +1470,26 @@ xfs_collapse_file_space(
 	start_fsb = XFS_B_TO_FSB(mp, offset + len);
 	shift_fsb = XFS_B_TO_FSB(mp, len);
 
+	/*
+	 * Writeback the entire file and force remove any post-eof blocks. The
+	 * writeback prevents changes to the extent list via concurrent
+	 * writeback and the eofblocks trim prevents the extent shift algorithm
+	 * from running into a post-eof delalloc extent.
+	 *
+	 * XXX: This is a temporary fix until the extent shift loop below is
+	 * converted to use offsets and lookups within the ILOCK rather than
+	 * carrying around the index into the extent list for the next
+	 * iteration.
+	 */
+	error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
+	if (error)
+		return error;
+	if (xfs_can_free_eofblocks(ip, true)) {
+		error = xfs_free_eofblocks(mp, ip, false);
+		if (error)
+			return error;
+	}
+
 	error = xfs_free_file_space(ip, offset, len);
 	if (error)
 		return error;