Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block

[linux-2.6-omap-h63xx.git] / drivers / md / dm-mpath.c

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index fea966d66f9838c140176a7dbd0ed8223e908f44..3d3848132c6925ae711734d45efc2380c23c9784 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -33,6 +33,7 @@ struct pgpath {
        unsigned fail_count;            /* Cumulative failure count */
 
        struct dm_path path;
+       struct work_struct deactivate_path;
 };
 
 #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
@@ -63,6 +64,7 @@ struct multipath {
 
        const char *hw_handler_name;
        struct work_struct activate_path;
+       struct pgpath *pgpath_to_activate;
        unsigned nr_priority_groups;
        struct list_head priority_groups;
        unsigned pg_init_required;      /* pg_init needs calling? */
@@ -111,6 +113,7 @@ 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 void deactivate_path(struct work_struct *work);
 
 
 /*-----------------------------------------------
@@ -121,8 +124,10 @@ static struct pgpath *alloc_pgpath(void)
 {
        struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL);
 
-       if (pgpath)
+       if (pgpath) {
                pgpath->path.is_active = 1;
+               INIT_WORK(&pgpath->deactivate_path, deactivate_path);
+       }
 
        return pgpath;
 }
@@ -132,6 +137,14 @@ static void free_pgpath(struct pgpath *pgpath)
        kfree(pgpath);
 }
 
+static void deactivate_path(struct work_struct *work)
+{
+       struct pgpath *pgpath =
+               container_of(work, struct pgpath, deactivate_path);
+
+       blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
+}
+
 static struct priority_group *alloc_priority_group(void)
 {
        struct priority_group *pg;
@@ -146,11 +159,19 @@ static struct priority_group *alloc_priority_group(void)
 
 static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
 {
+       unsigned long flags;
        struct pgpath *pgpath, *tmp;
+       struct multipath *m = ti->private;
 
        list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
                list_del(&pgpath->list);
+               if (m->hw_handler_name)
+                       scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev));
                dm_put_device(ti, pgpath->path.dev);
+               spin_lock_irqsave(&m->lock, flags);
+               if (m->pgpath_to_activate == pgpath)
+                       m->pgpath_to_activate = NULL;
+               spin_unlock_irqrestore(&m->lock, flags);
                free_pgpath(pgpath);
        }
 }
@@ -418,6 +439,7 @@ static void process_queued_ios(struct work_struct *work)
                __choose_pgpath(m);
 
        pgpath = m->current_pgpath;
+       m->pgpath_to_activate = m->current_pgpath;
 
        if ((pgpath && !m->queue_io) ||
            (!pgpath && !m->queue_if_no_path))
@@ -548,6 +570,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
 {
        int r;
        struct pgpath *p;
+       struct multipath *m = ti->private;
 
        /* we need at least a path arg */
        if (as->argc < 1) {
@@ -566,6 +589,15 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
                goto bad;
        }
 
+       if (m->hw_handler_name) {
+               r = scsi_dh_attach(bdev_get_queue(p->path.dev->bdev),
+                                  m->hw_handler_name);
+               if (r < 0) {
+                       dm_put_device(ti, p->path.dev);
+                       goto bad;
+               }
+       }
+
        r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error);
        if (r) {
                dm_put_device(ti, p->path.dev);
@@ -850,6 +882,7 @@ static int fail_path(struct pgpath *pgpath)
                      pgpath->path.dev->name, m->nr_valid_paths);
 
        queue_work(kmultipathd, &m->trigger_event);
+       queue_work(kmultipathd, &pgpath->deactivate_path);
 
 out:
        spin_unlock_irqrestore(&m->lock, flags);
@@ -1080,8 +1113,15 @@ static void activate_path(struct work_struct *work)
        int ret;
        struct multipath *m =
                container_of(work, struct multipath, activate_path);
-       struct dm_path *path = &m->current_pgpath->path;
+       struct dm_path *path;
+       unsigned long flags;
 
+       spin_lock_irqsave(&m->lock, flags);
+       path = &m->pgpath_to_activate->path;
+       m->pgpath_to_activate = NULL;
+       spin_unlock_irqrestore(&m->lock, flags);
+       if (!path)
+               return;
        ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev));
        pg_init_done(path, ret);
 }