From: Brian Foster <bfoster@redhat.com>
To: xfs@oss.sgi.com
Subject: [PATCH RFC 2/2] xfs: drop xa_lock around log force in xfs_buf_item push
Date: Tue, 29 Jan 2013 15:42:37 -0500 [thread overview]
Message-ID: <1359492157-30521-3-git-send-email-bfoster@redhat.com> (raw)
In-Reply-To: <1359492157-30521-1-git-send-email-bfoster@redhat.com>
If the trylock fails and the buffer is pinned and stale, the
resulting xfs_log_force() can lead to lock recursion on the ailp
xa_lock. Call __xfs_buf_trylock() to attempt the buf lock with
xa_lock held, but to avoid the log force. We subsequently pull the
check and log force up into xfs_buf_item_push() where we can drop
and reacquire xa_lock appropriately.
Signed-off-by: Brian Foster <bfoster@redhat.com>
---
fs/xfs/xfs_buf_item.c | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletions(-)
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 9c4c050..7b6e98a 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -469,8 +469,16 @@ xfs_buf_item_push(
if (xfs_buf_ispinned(bp))
return XFS_ITEM_PINNED;
- if (!xfs_buf_trylock(bp))
+
+ if (!__xfs_buf_trylock(bp, false)) {
+ if (atomic_read(&bp->b_pin_count) &&
+ (bp->b_flags & XBF_STALE)) {
+ spin_unlock(&lip->li_ailp->xa_lock);
+ xfs_log_force(bp->b_target->bt_mount, 0);
+ spin_lock(&lip->li_ailp->xa_lock);
+ }
return XFS_ITEM_LOCKED;
+ }
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
--
1.7.7.6
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next prev parent reply other threads:[~2013-01-29 20:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-29 20:42 [PATCH RFC 0/2] fix spinlock recursion on xa_lock in xfs_buf_item_push Brian Foster
2013-01-29 20:42 ` [PATCH RFC 1/2] xfs: conditionally force log on trylock failure of pinned/stale buf Brian Foster
2013-01-29 20:42 ` Brian Foster [this message]
2013-01-29 22:41 ` [PATCH RFC 0/2] fix spinlock recursion on xa_lock in xfs_buf_item_push Mark Tinguely
2013-01-30 6:05 ` Dave Chinner
[not found] ` <5109291E.6090303@sgi.com>
2013-01-30 16:02 ` Brian Foster
2013-01-30 21:59 ` Dave Chinner
2013-01-31 17:45 ` Brian Foster
2013-02-01 1:26 ` Dave Chinner
2013-02-01 16:01 ` Brian Foster
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