/spare/repo/netdev-2.6 branch 'master'

[linux-2.6] / drivers / md / dm-mpath.c

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 98da8eee2d2c308156c124ed18dcd3d3a16090b8..785806bdb2485d8c5d5d8b0249b9b63bb8b5a750 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -63,6 +63,7 @@ struct multipath {
        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 @@ static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio,
                /* 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 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path)
 
        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 @@ static void process_queued_ios(void *data)
 {
        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 @@ static int reinstate_path(struct pgpath *pgpath)
        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 @@ void dm_pg_init_complete(struct path *path, unsigned err_flags)
                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);
 }