Patch "xfs: tune down agno asserts in the bmap code" has been added to the 4.10-stable tree

Patch "xfs: tune down agno asserts in the bmap code" has been added to the 4.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    xfs: tune down agno asserts in the bmap code

to the 4.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfs-tune-down-agno-asserts-in-the-bmap-code.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 410d17f67e583559be3a922f8b6cc336331893f3 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 16 Feb 2017 17:12:51 -0800
Subject: xfs: tune down agno asserts in the bmap code

From: Christoph Hellwig <hch@lst.de>

commit 410d17f67e583559be3a922f8b6cc336331893f3 upstream.

In various places we currently assert that xfs_bmap_btalloc allocates
from the same as the firstblock value passed in, unless it's either
NULLAGNO or the dop_low flag is set.  But the reflink code does not
fully follow this convention as it passes in firstblock purely as
a hint for the allocator without actually having previous allocations
in the transaction, and without having a minleft check on the current
AG, leading to the assert firing on a very full and heavily used
file system.  As even the reflink code only allocates from equal or
higher AGs for now we can simply the check to always allow for equal
or higher AGs.

Note that we need to eventually split the two meanings of the firstblock
value.  At that point we can also allow the reflink code to allocate
from any AG instead of limiting it in any way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/xfs/libxfs/xfs_bmap.c |   22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -804,9 +804,7 @@ try_another_ag:
 	 */
 	ASSERT(args.fsbno != NULLFSBLOCK);
 	ASSERT(*firstblock == NULLFSBLOCK ||
-	       args.agno == XFS_FSB_TO_AGNO(mp, *firstblock) ||
-	       (dfops->dop_low &&
-		args.agno > XFS_FSB_TO_AGNO(mp, *firstblock)));
+	       args.agno >= XFS_FSB_TO_AGNO(mp, *firstblock));
 	*firstblock = cur->bc_private.b.firstblock = args.fsbno;
 	cur->bc_private.b.allocated++;
 	ip->i_d.di_nblocks++;
@@ -3832,17 +3830,13 @@ xfs_bmap_btalloc(
 		 * the first block that was allocated.
 		 */
 		ASSERT(*ap->firstblock == NULLFSBLOCK ||
-		       XFS_FSB_TO_AGNO(mp, *ap->firstblock) ==
-		       XFS_FSB_TO_AGNO(mp, args.fsbno) ||
-		       (ap->dfops->dop_low &&
-			XFS_FSB_TO_AGNO(mp, *ap->firstblock) <
-			XFS_FSB_TO_AGNO(mp, args.fsbno)));
+		       XFS_FSB_TO_AGNO(mp, *ap->firstblock) <=
+		       XFS_FSB_TO_AGNO(mp, args.fsbno));
 
 		ap->blkno = args.fsbno;
 		if (*ap->firstblock == NULLFSBLOCK)
 			*ap->firstblock = args.fsbno;
-		ASSERT(nullfb || fb_agno == args.agno ||
-		       (ap->dfops->dop_low && fb_agno < args.agno));
+		ASSERT(nullfb || fb_agno <= args.agno);
 		ap->length = args.len;
 		if (!(ap->flags & XFS_BMAPI_COWFORK))
 			ap->ip->i_d.di_nblocks += args.len;
@@ -4764,13 +4758,9 @@ error0:
 	if (bma.cur) {
 		if (!error) {
 			ASSERT(*firstblock == NULLFSBLOCK ||
-			       XFS_FSB_TO_AGNO(mp, *firstblock) ==
+			       XFS_FSB_TO_AGNO(mp, *firstblock) <=
 			       XFS_FSB_TO_AGNO(mp,
-				       bma.cur->bc_private.b.firstblock) ||
-			       (dfops->dop_low &&
-				XFS_FSB_TO_AGNO(mp, *firstblock) <
-				XFS_FSB_TO_AGNO(mp,
-					bma.cur->bc_private.b.firstblock)));
+				       bma.cur->bc_private.b.firstblock));
 			*firstblock = bma.cur->bc_private.b.firstblock;
 		}
 		xfs_btree_del_cursor(bma.cur,


Patches currently in stable-queue which might be from hch@lst.de are

queue-4.10/xfs-mark-speculative-prealloc-cow-fork-extents-unwritten.patch
queue-4.10/xfs-fix-toctou-race-when-locking-an-inode-to-access-the-data-map.patch
queue-4.10/xfs-use-iomap-new-flag-for-newly-allocated-delalloc-blocks.patch
queue-4.10/xfs-reject-all-unaligned-direct-writes-to-reflinked-files.patch
queue-4.10/xfs-allow-unwritten-extents-in-the-cow-fork.patch
queue-4.10/xfs-tune-down-agno-asserts-in-the-bmap-code.patch
queue-4.10/xfs-verify-free-block-header-fields.patch
queue-4.10/xfs-check-for-obviously-bad-level-values-in-the-bmbt-root.patch
queue-4.10/xfs-don-t-fail-xfs_extent_busy-allocation.patch
queue-4.10/xfs-sync-eofblocks-scans-under-iolock-are-livelock-prone.patch
queue-4.10/xfs-pull-up-iolock-from-xfs_free_eofblocks.patch
queue-4.10/xfs-fail-_dir_open-when-readahead-fails.patch
queue-4.10/xfs-update-ctime-and-mtime-on-clone-destinatation-inodes.patch
queue-4.10/xfs-use-xfs_icluster_size_fsb-to-calculate-inode-chunk-alignment.patch
queue-4.10/xfs-only-reclaim-unwritten-cow-extents-periodically.patch
queue-4.10/xfs-try-any-ag-when-allocating-the-first-btree-block-when-reflinking.patch
queue-4.10/xfs-fix-and-streamline-error-handling-in-xfs_end_io.patch
queue-4.10/xfs-fix-eofblocks-race-with-file-extending-async-dio-writes.patch