Input: ad7877 - keep dma rx buffers in seperate cache lines

[pandora-kernel.git] / drivers / md / dm-mpath.c

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e81345a..826bce7 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -69,6 +69,7 @@ struct multipath {
        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 */
+       wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */
 
        unsigned nr_valid_paths;        /* Total number of usable paths */
        struct pgpath *current_pgpath;
@@ -95,8 +96,6 @@ struct multipath {
        mempool_t *mpio_pool;
 
        struct mutex work_mutex;
-
-       unsigned suspended;     /* Don't create new I/O internally when set. */
 };
 
 /*
@@ -202,6 +201,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
                m->queue_io = 1;
                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);
                m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
                if (!m->mpio_pool) {
@@ -235,6 +235,21 @@ static void free_multipath(struct multipath *m)
  * Path selection
  *-----------------------------------------------*/
 
+static void __pg_init_all_paths(struct multipath *m)
+{
+       struct pgpath *pgpath;
+
+       m->pg_init_count++;
+       m->pg_init_required = 0;
+       list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
+               /* Skip failed paths */
+               if (!pgpath->is_active)
+                       continue;
+               if (queue_work(kmpath_handlerd, &pgpath->activate_path))
+                       m->pg_init_in_progress++;
+       }
+}
+
 static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
 {
        m->current_pg = pgpath->pg;
@@ -439,7 +454,7 @@ static void process_queued_ios(struct work_struct *work)
 {
        struct multipath *m =
                container_of(work, struct multipath, process_queued_ios);
-       struct pgpath *pgpath = NULL, *tmp;
+       struct pgpath *pgpath = NULL;
        unsigned must_queue = 1;
        unsigned long flags;
 
@@ -457,14 +472,9 @@ static void process_queued_ios(struct work_struct *work)
            (!pgpath && !m->queue_if_no_path))
                must_queue = 0;
 
-       if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
-               m->pg_init_count++;
-               m->pg_init_required = 0;
-               list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
-                       if (queue_work(kmpath_handlerd, &tmp->activate_path))
-                               m->pg_init_in_progress++;
-               }
-       }
+       if (m->pg_init_required && !m->pg_init_in_progress && pgpath)
+               __pg_init_all_paths(m);
+
 out:
        spin_unlock_irqrestore(&m->lock, flags);
        if (!must_queue)
@@ -597,8 +607,8 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
        if (!p)
                return ERR_PTR(-ENOMEM);
 
-       r = dm_get_device(ti, shift(as), ti->begin, ti->len,
-                         dm_table_get_mode(ti->table), &p->path.dev);
+       r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table),
+                         &p->path.dev);
        if (r) {
                ti->error = "error getting device";
                goto bad;
@@ -890,9 +900,34 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
        return r;
 }
 
-static void flush_multipath_work(void)
+static void multipath_wait_for_pg_init_completion(struct multipath *m)
+{
+       DECLARE_WAITQUEUE(wait, current);
+       unsigned long flags;
+
+       add_wait_queue(&m->pg_init_wait, &wait);
+
+       while (1) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+
+               spin_lock_irqsave(&m->lock, flags);
+               if (!m->pg_init_in_progress) {
+                       spin_unlock_irqrestore(&m->lock, flags);
+                       break;
+               }
+               spin_unlock_irqrestore(&m->lock, flags);
+
+               io_schedule();
+       }
+       set_current_state(TASK_RUNNING);
+
+       remove_wait_queue(&m->pg_init_wait, &wait);
+}
+
+static void flush_multipath_work(struct multipath *m)
 {
        flush_workqueue(kmpath_handlerd);
+       multipath_wait_for_pg_init_completion(m);
        flush_workqueue(kmultipathd);
        flush_scheduled_work();
 }
@@ -901,7 +936,7 @@ static void multipath_dtr(struct dm_target *ti)
 {
        struct multipath *m = ti->private;
 
-       flush_multipath_work();
+       flush_multipath_work(m);
        free_multipath(m);
 }
 
@@ -1128,8 +1163,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
 
 static void pg_init_done(void *data, int errors)
 {
-       struct dm_path *path = data;
-       struct pgpath *pgpath = path_to_pgpath(path);
+       struct pgpath *pgpath = data;
        struct priority_group *pg = pgpath->pg;
        struct multipath *m = pg->m;
        unsigned long flags;
@@ -1143,8 +1177,8 @@ static void pg_init_done(void *data, int errors)
                        errors = 0;
                        break;
                }
-               DMERR("Cannot failover device because scsi_dh_%s was not "
-                     "loaded.", m->hw_handler_name);
+               DMERR("Could not failover the device: Handler scsi_dh_%s "
+                     "Error %d.", m->hw_handler_name, errors);
                /*
                 * Fail path for now, so we do not ping pong
                 */
@@ -1181,14 +1215,24 @@ static void pg_init_done(void *data, int errors)
                        m->current_pgpath = NULL;
                        m->current_pg = NULL;
                }
-       } else if (!m->pg_init_required) {
-               m->queue_io = 0;
+       } else if (!m->pg_init_required)
                pg->bypassed = 0;
-       }
 
-       m->pg_init_in_progress--;
-       if (!m->pg_init_in_progress)
-               queue_work(kmultipathd, &m->process_queued_ios);
+       if (--m->pg_init_in_progress)
+               /* Activations of other paths are still on going */
+               goto out;
+
+       if (!m->pg_init_required)
+               m->queue_io = 0;
+
+       queue_work(kmultipathd, &m->process_queued_ios);
+
+       /*
+        * Wake up any thread waiting to suspend.
+        */
+       wake_up(&m->pg_init_wait);
+
+out:
        spin_unlock_irqrestore(&m->lock, flags);
 }
 
@@ -1198,7 +1242,7 @@ static void activate_path(struct work_struct *work)
                container_of(work, struct pgpath, activate_path);
 
        scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
-                               pg_init_done, &pgpath->path);
+                               pg_init_done, pgpath);
 }
 
 /*
@@ -1276,8 +1320,7 @@ static void multipath_postsuspend(struct dm_target *ti)
        struct multipath *m = ti->private;
 
        mutex_lock(&m->work_mutex);
-       m->suspended = 1;
-       flush_multipath_work();
+       flush_multipath_work(m);
        mutex_unlock(&m->work_mutex);
 }
 
@@ -1289,10 +1332,6 @@ static void multipath_resume(struct dm_target *ti)
        struct multipath *m = (struct multipath *) ti->private;
        unsigned long flags;
 
-       mutex_lock(&m->work_mutex);
-       m->suspended = 0;
-       mutex_unlock(&m->work_mutex);
-
        spin_lock_irqsave(&m->lock, flags);
        m->queue_if_no_path = m->saved_queue_if_no_path;
        spin_unlock_irqrestore(&m->lock, flags);
@@ -1428,11 +1467,6 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
 
        mutex_lock(&m->work_mutex);
 
-       if (m->suspended) {
-               r = -EBUSY;
-               goto out;
-       }
-
        if (dm_suspended(ti)) {
                r = -EBUSY;
                goto out;
@@ -1471,8 +1505,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
                goto out;
        }
 
-       r = dm_get_device(ti, argv[1], ti->begin, ti->len,
-                         dm_table_get_mode(ti->table), &dev);
+       r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
        if (r) {
                DMWARN("message: error getting device %s",
                       argv[1]);