Prevent more than one priority group initialisation function from being
outstanding at once. Otherwise the completion functions interfere with
each other. Also, reloading the table could reference a freed pointer.
Only reset queue_io in pg_init_complete if another pg_init isn't required.
Skip process_queued_ios if the queue is empty so that we only trigger a
pg_init if there's I/O.
Signed-off-by: Lars Marowsky-Bree <[EMAIL PROTECTED]>
Signed-Off-By: Alasdair G Kergon <[EMAIL PROTECTED]>
--- diff/drivers/md/dm-mpath.c 2005-07-08 20:24:55.000000000 +0100
+++ source/drivers/md/dm-mpath.c 2005-07-08 20:26:10.000000000 +0100
@@ -63,6 +63,7 @@
unsigned nr_priority_groups;
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
+ unsigned pg_init_in_progress; /* Only one pg_init allowed at once */
unsigned nr_valid_paths; /* Total number of usable paths */
struct pgpath *current_pgpath;
@@ -308,7 +309,8 @@
/* Queue for the daemon to resubmit */
bio_list_add(&m->queued_ios, bio);
m->queue_size++;
- if (m->pg_init_required || !m->queue_io)
+ if ((m->pg_init_required && !m->pg_init_in_progress) ||
+ !m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
r = 0;
@@ -335,7 +337,7 @@
m->saved_queue_if_no_path = m->queue_if_no_path;
m->queue_if_no_path = queue_if_no_path;
- if (!m->queue_if_no_path)
+ if (!m->queue_if_no_path && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
@@ -380,25 +382,31 @@
{
struct multipath *m = (struct multipath *) data;
struct hw_handler *hwh = &m->hw_handler;
- struct pgpath *pgpath;
- unsigned init_required, must_queue = 0;
+ struct pgpath *pgpath = NULL;
+ unsigned init_required = 0, must_queue = 1;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
+ if (!m->queue_size)
+ goto out;
+
if (!m->current_pgpath)
__choose_pgpath(m);
pgpath = m->current_pgpath;
- if ((pgpath && m->queue_io) ||
- (!pgpath && m->queue_if_no_path))
- must_queue = 1;
+ if ((pgpath && !m->queue_io) ||
+ (!pgpath && !m->queue_if_no_path))
+ must_queue = 0;
- init_required = m->pg_init_required;
- if (init_required)
+ if (m->pg_init_required && !m->pg_init_in_progress) {
m->pg_init_required = 0;
+ m->pg_init_in_progress = 1;
+ init_required = 1;
+ }
+out:
spin_unlock_irqrestore(&m->lock, flags);
if (init_required)
@@ -843,7 +851,7 @@
pgpath->path.is_active = 1;
m->current_pgpath = NULL;
- if (!m->nr_valid_paths++)
+ if (!m->nr_valid_paths++ && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
queue_work(kmultipathd, &m->trigger_event);
@@ -969,12 +977,13 @@
bypass_pg(m, pg, 1);
spin_lock_irqsave(&m->lock, flags);
- if (!err_flags)
- m->queue_io = 0;
- else {
+ if (err_flags) {
m->current_pgpath = NULL;
m->current_pg = NULL;
- }
+ } else if (!m->pg_init_required)
+ m->queue_io = 0;
+
+ m->pg_init_in_progress = 0;
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
}
-
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