Patch "xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write

to the 4.9-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-set-firstfsb-to-nullfsblock-before-feeding-it-to-_bmapi_write.patch
and it can be found in the queue-4.9 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 hch@lst.de  Mon Sep 18 10:08:30 2017
From: Christoph Hellwig <hch@lst.de>
Date: Sun, 17 Sep 2017 14:06:37 -0700
Subject: xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write
To: stable@vger.kernel.org
Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" <darrick.wong@oracle.com>
Message-ID: <20170917210712.10804-13-hch@lst.de>


From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 4c1a67bd3606540b9b42caff34a1d5cd94b1cf65 upstream.

We must initialize the firstfsb parameter to _bmapi_write so that it
doesn't incorrectly treat stack garbage as a restriction on which AGs
it can search for free space.

Fixes-coverity-id: 1402025
Fixes-coverity-id: 1415167
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/xfs/libxfs/xfs_bmap.c |    9 +++++++++
 fs/xfs/xfs_reflink.c     |    2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -6639,6 +6639,15 @@ xfs_bmap_finish_one(
 	bmap.br_blockcount = *blockcount;
 	bmap.br_state = state;
 
+	/*
+	 * firstfsb is tied to the transaction lifetime and is used to
+	 * ensure correct AG locking order and schedule work item
+	 * continuations.  XFS_BUI_MAX_FAST_EXTENTS (== 1) restricts us
+	 * to only making one bmap call per transaction, so it should
+	 * be safe to have it as a local variable here.
+	 */
+	firstfsb = NULLFSBLOCK;
+
 	trace_xfs_bmap_deferred(tp->t_mountp,
 			XFS_FSB_TO_AGNO(tp->t_mountp, startblock), type,
 			XFS_FSB_TO_AGBNO(tp->t_mountp, startblock),
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -333,7 +333,7 @@ xfs_reflink_convert_cow_extent(
 	struct xfs_defer_ops		*dfops)
 {
 	struct xfs_bmbt_irec		irec = *imap;
-	xfs_fsblock_t			first_block;
+	xfs_fsblock_t			first_block = NULLFSBLOCK;
 	int				nimaps = 1;
 
 	if (imap->br_state == XFS_EXT_NORM)


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

queue-4.9/xfs-fix-inobt-inode-allocation-search-optimization.patch
queue-4.9/xfs-try-to-avoid-blowing-out-the-transaction-reservation-when-bunmaping-a-shared-extent.patch
queue-4.9/xfs-free-cowblocks-and-retry-on-buffered-write-enospc.patch
queue-4.9/xfs-set-firstfsb-to-nullfsblock-before-feeding-it-to-_bmapi_write.patch
queue-4.9/xfs-fix-quotacheck-dquot-id-overflow-infinite-loop.patch
queue-4.9/xfs-remove-bli-from-ail-before-release-on-transaction-abort.patch
queue-4.9/xfs-check-_btree_check_block-value.patch
queue-4.9/xfs-don-t-allow-bmap-on-rt-files.patch
queue-4.9/xfs-free-uncommitted-transactions-during-log-recovery.patch
queue-4.9/xfs-don-t-crash-on-unexpected-holes-in-dir-attr-btrees.patch
queue-4.9/xfs-fix-spurious-spin_is_locked-assert-failures-on-non-smp-kernels.patch
queue-4.9/xfs-fix-per-inode-dax-flag-inheritance.patch
queue-4.9/xfs-fix-multi-ag-deadlock-in-xfs_bunmapi.patch
queue-4.9/xfs-release-bli-from-transaction-properly-on-fs-shutdown.patch
queue-4.9/xfs-check-_alloc_read_agf-buffer-pointer-before-using.patch