From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Thornber Subject: [PATCH 2/4] Fix a race between reading a new block and having it recycled. Date: Tue, 2 Aug 2011 15:36:46 +0100 Message-ID: <1312295808-4323-2-git-send-email-ejt@redhat.com> References: <1312295808-4323-1-git-send-email-ejt@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1312295808-4323-1-git-send-email-ejt@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: mpatocka@redhat.com Cc: dm-devel@redhat.com, Joe Thornber List-Id: dm-devel.ids --- drivers/md/persistent-data/dm-block-manager.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c index c9fb132..b68be88 100644 --- a/drivers/md/persistent-data/dm-block-manager.c +++ b/drivers/md/persistent-data/dm-block-manager.c @@ -447,6 +447,7 @@ static int recycle_block(struct dm_block_manager *bm, dm_block_t where, * Wait for a block to appear on the empty or clean lists. */ spin_lock_irqsave(&bm->lock, flags); +retry: while (1) { /* * Once we can lock and do io concurrently then we should @@ -486,7 +487,11 @@ static int recycle_block(struct dm_block_manager *bm, dm_block_t where, spin_lock_irqsave(&bm->lock, flags); __wait_io(b, &flags); - /* FIXME: Can b have been recycled between io completion and here? */ + /* + * Has b been recycled whilst we were unlocked? + */ + if (b->where != where) + goto retry; /* * Did the io succeed? -- 1.7.4.1