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| author | Kiyoshi Ueda <k-ueda@ct.jp.nec.com> | 2011-01-13 20:00:00 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-01-13 20:00:00 +0000 |
| commit | 052189a2ec956810feefb6a681416c5e6a207646 (patch) | |
| tree | 52a1fbec2878788c6a2f6565999b97331493bc4c /drivers | |
| parent | dbc883f1570d992ba926a8c9e22140ba473c6cc1 (diff) | |
| download | linux-052189a2ec956810feefb6a681416c5e6a207646.tar.bz2 | |
dm: remove superfluous irq disablement in dm_request_fn
This patch changes spin_lock_irq() to spin_lock() in dm_request_fn().
This patch is just a clean-up and no functional change.
The spin_lock_irq() was leftover from the early request-based dm code,
where map_request() used to enable interrupts.
Since current map_request() never enables interrupts, we can change it
to spin_lock() to match the prior spin_unlock().
Auditing through the dm and block-layer code called from
map_request(), I confirmed all functions save/restore interrupt
status, so no function returning with interrupts enabled.
Also I haven't observed any problem on my test environment which
uses scsi and lpfc driver after heavy I/O testing with occasional
path down/up.
Added BUG_ON() to detect breakage in future.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/dm.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index e504bb40d60e..eaa3af0e0632 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1637,13 +1637,15 @@ static void dm_request_fn(struct request_queue *q) if (map_request(ti, clone, md)) goto requeued; - spin_lock_irq(q->queue_lock); + BUG_ON(!irqs_disabled()); + spin_lock(q->queue_lock); } goto out; requeued: - spin_lock_irq(q->queue_lock); + BUG_ON(!irqs_disabled()); + spin_lock(q->queue_lock); plug_and_out: if (!elv_queue_empty(q)) |