[dm-devel] [PATCH 3/5] dm-multipath: remove process_queued_ios()
Hannes Reinecke
hare at suse.de
Fri Jan 31 09:10:42 UTC 2014
Doesn't serve any real purpose anymore; dm_table_run_queue()
will already move things to a workqueue, so we don't need
to do it ourselves.
Signed-off-by: Hannes Reinecke <hare at suse.de>
---
drivers/md/dm-mpath.c | 67 ++++++++++++++++++++-------------------------------
1 file changed, 26 insertions(+), 41 deletions(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 39fd166..7122ac3 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -93,8 +93,6 @@ struct multipath {
unsigned pg_init_count; /* Number of times pg_init called */
unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */
- struct work_struct process_queued_ios;
-
struct work_struct trigger_event;
/*
@@ -119,7 +117,6 @@ typedef int (*action_fn) (struct pgpath *pgpath);
static struct kmem_cache *_mpio_cache;
static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
-static void process_queued_ios(struct work_struct *work);
static void trigger_event(struct work_struct *work);
static void activate_path(struct work_struct *work);
static int __pgpath_busy(struct pgpath *pgpath);
@@ -197,7 +194,6 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
spin_lock_init(&m->lock);
m->queue_io = 1;
m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
- INIT_WORK(&m->process_queued_ios, process_queued_ios);
INIT_WORK(&m->trigger_event, trigger_event);
init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
@@ -438,41 +434,13 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path,
m->saved_queue_if_no_path = queue_if_no_path;
m->queue_if_no_path = queue_if_no_path;
if (!m->queue_if_no_path)
- queue_work(kmultipathd, &m->process_queued_ios);
+ dm_table_run_queue(m->ti->table);
spin_unlock_irqrestore(&m->lock, flags);
return 0;
}
-static void process_queued_ios(struct work_struct *work)
-{
- struct multipath *m =
- container_of(work, struct multipath, process_queued_ios);
- struct pgpath *pgpath = NULL;
- unsigned must_queue = 1;
- unsigned long flags;
-
- spin_lock_irqsave(&m->lock, flags);
-
- if (!m->current_pgpath)
- __choose_pgpath(m, 0);
-
- pgpath = m->current_pgpath;
-
- if ((pgpath && !m->queue_io) ||
- (!pgpath && !m->queue_if_no_path))
- must_queue = 0;
-
- if (m->pg_init_required && !m->pg_init_in_progress && pgpath &&
- !m->pg_init_disabled)
- __pg_init_all_paths(m);
-
- spin_unlock_irqrestore(&m->lock, flags);
- if (!must_queue)
- dm_table_run_queue(m->ti->table);
-}
-
/*
* An event is triggered whenever a path is taken out of use.
* Includes path failure and PG bypass.
@@ -1019,7 +987,7 @@ static int reinstate_path(struct pgpath *pgpath)
if (!m->nr_valid_paths++) {
m->current_pgpath = NULL;
- queue_work(kmultipathd, &m->process_queued_ios);
+ dm_table_run_queue(m->ti->table);
} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
if (queue_work(kmpath_handlerd, &pgpath->activate_path.work))
m->pg_init_in_progress++;
@@ -1158,7 +1126,7 @@ static void pg_init_done(void *data, int errors)
struct priority_group *pg = pgpath->pg;
struct multipath *m = pg->m;
unsigned long flags;
- unsigned delay_retry = 0;
+ unsigned long pg_init_delay = 0;
/* device or driver problems */
switch (errors) {
@@ -1185,7 +1153,7 @@ static void pg_init_done(void *data, int errors)
break;
case SCSI_DH_RETRY:
/* Wait before retrying. */
- delay_retry = 1;
+ pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs);
case SCSI_DH_IMM_RETRY:
case SCSI_DH_RES_TEMP_UNAVAIL:
if (pg_init_limit_reached(m, pgpath))
@@ -1217,9 +1185,21 @@ static void pg_init_done(void *data, int errors)
if (!m->pg_init_required)
m->queue_io = 0;
-
- m->pg_init_delay_retry = delay_retry;
- queue_work(kmultipathd, &m->process_queued_ios);
+ else {
+ if (!pg_init_delay) {
+ m->pg_init_delay_retry = 0;
+ /*
+ * Add a small delay to move the
+ * activation to a workqueue
+ */
+ pg_init_delay = HZ / 50;
+ } else
+ m->pg_init_delay_retry = 1;
+ if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path,
+ pg_init_delay))
+ m->pg_init_in_progress++;
+ goto out;
+ }
/*
* Wake up any thread waiting to suspend.
@@ -1593,8 +1573,13 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
r = scsi_verify_blk_ioctl(NULL, cmd);
- if (r == -ENOTCONN && !fatal_signal_pending(current))
- queue_work(kmultipathd, &m->process_queued_ios);
+ if (r == -ENOTCONN && !fatal_signal_pending(current)) {
+ spin_lock_irqsave(&m->lock, flags);
+ if (m->current_pgpath && m->pg_init_required)
+ __pg_init_all_paths(m);
+ spin_unlock_irqrestore(&m->lock, flags);
+ dm_table_run_queue(m->ti->table);
+ }
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
}
--
1.7.12.4
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