Messages in this thread Patch in this message | | | Date | Thu, 21 Aug 2008 12:37:23 +0100 | From | Alex Nixon <> | Subject | [PATCH] Xen: Fix warning when hot-unplugging virtual block devices |
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From: Alex Nixon <alex.nixon@citrix.com> Date: Thu, 21 Aug 2008 12:30:54 +0100 Subject: [PATCH] Xen: Fix warning when hot-unplugging virtual block devices
WARNING: at kernel/softirq.c:136 local_bh_enable+0x3f/0x8a()
del_gendisk needs IRQs enabled, as the code path eventually reaches local_bh_enable. blk_stop_queue needs them disabled - so do so temporarily.
It shouldn't matter if an interrupt comes in whilst blkif_io_lock is held, as it will block on the lock. Upon acquisition, it'll realise the device is down and exit cleanly.
Signed-off-by: Alex Nixon <alex.nixon@citrix.com> --- drivers/block/xen-blkfront.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index d5e7532..95cee2c 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -899,16 +899,18 @@ static void blkfront_closing(struct xenbus_device *dev) if (info->rq == NULL) goto out; - spin_lock_irqsave(&blkif_io_lock, flags); + spin_lock(&blkif_io_lock); del_gendisk(info->gd); + local_irq_save(flags); /* No more blkif_request(). */ blk_stop_queue(info->rq); + local_irq_restore(flags); /* No more gnttab callback work. */ gnttab_cancel_free_callback(&info->callback); - spin_unlock_irqrestore(&blkif_io_lock, flags); + spin_unlock(&blkif_io_lock); /* Flush gnttab callback work. Must be done with no locks held. */ flush_scheduled_work(); -- 1.5.4.3
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