Patch "xfs: fix spurious spin_is_locked() assert failures on non-smp kernels" 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: fix spurious spin_is_locked() assert failures on non-smp kernels

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-fix-spurious-spin_is_locked-assert-failures-on-non-smp-kernels.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 95989c46d2a156365867b1d795fdefce71bce378 Mon Sep 17 00:00:00 2001
From: Brian Foster <bfoster@redhat.com>
Date: Thu, 8 Jun 2017 08:23:07 -0700
Subject: xfs: fix spurious spin_is_locked() assert failures on non-smp kernels

From: Brian Foster <bfoster@redhat.com>

commit 95989c46d2a156365867b1d795fdefce71bce378 upstream.

The 0-day kernel test robot reports assertion failures on
!CONFIG_SMP kernels due to failed spin_is_locked() checks. As it
turns out, spin_is_locked() is hardcoded to return zero on
!CONFIG_SMP kernels and so this function cannot be relied on to
verify spinlock state in this configuration.

To avoid this problem, replace the associated asserts with lockdep
variants that do the right thing regardless of kernel configuration.
Drop the one assert that checks for an unlocked lock as there is no
suitable lockdep variant for that case. This moves the spinlock
checks from XFS debug code to lockdep, but generally provides the
same level of protection.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-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/xfs_buf.c    |    2 +-
 fs/xfs/xfs_icache.c |    5 ++---
 2 files changed, 3 insertions(+), 4 deletions(-)

--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -116,7 +116,7 @@ static inline void
 __xfs_buf_ioacct_dec(
 	struct xfs_buf	*bp)
 {
-	ASSERT(spin_is_locked(&bp->b_lock));
+	lockdep_assert_held(&bp->b_lock);
 
 	if (bp->b_state & XFS_BSTATE_IN_FLIGHT) {
 		bp->b_state &= ~XFS_BSTATE_IN_FLIGHT;
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -66,7 +66,6 @@ xfs_inode_alloc(
 
 	XFS_STATS_INC(mp, vn_active);
 	ASSERT(atomic_read(&ip->i_pincount) == 0);
-	ASSERT(!spin_is_locked(&ip->i_flags_lock));
 	ASSERT(!xfs_isiflocked(ip));
 	ASSERT(ip->i_ino == 0);
 
@@ -192,7 +191,7 @@ xfs_perag_set_reclaim_tag(
 {
 	struct xfs_mount	*mp = pag->pag_mount;
 
-	ASSERT(spin_is_locked(&pag->pag_ici_lock));
+	lockdep_assert_held(&pag->pag_ici_lock);
 	if (pag->pag_ici_reclaimable++)
 		return;
 
@@ -214,7 +213,7 @@ xfs_perag_clear_reclaim_tag(
 {
 	struct xfs_mount	*mp = pag->pag_mount;
 
-	ASSERT(spin_is_locked(&pag->pag_ici_lock));
+	lockdep_assert_held(&pag->pag_ici_lock);
 	if (--pag->pag_ici_reclaimable)
 		return;
 


Patches currently in stable-queue which might be from bfoster@redhat.com are

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-push-buffer-of-flush-locked-dquot-to-avoid-quotacheck-deadlock.patch
queue-4.9/xfs-free-uncommitted-transactions-during-log-recovery.patch
queue-4.9/xfs-fix-spurious-spin_is_locked-assert-failures-on-non-smp-kernels.patch
queue-4.9/xfs-move-handling-of-missing-page-into-one-place-in-xfs_find_get_desired_pgoff.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