- Update to 3.4-rc7.

[linux-flexiantxendom0-3.2.10.git] / drivers / md / dm-mpath.c

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 1aecbf6..6195bff 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -226,6 +226,27 @@ static void free_multipath(struct multipath *m)
        kfree(m);
 }
 
+static int set_mapinfo(struct multipath *m, union map_info *info)
+{
+       struct dm_mpath_io *mpio;
+
+       mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
+       if (!mpio)
+               return -ENOMEM;
+
+       memset(mpio, 0, sizeof(*mpio));
+       info->ptr = mpio;
+
+       return 0;
+}
+
+static void clear_mapinfo(struct multipath *m, union map_info *info)
+{
+       struct dm_mpath_io *mpio = info->ptr;
+
+       info->ptr = NULL;
+       mempool_free(mpio, m->mpio_pool);
+}
 
 /*-----------------------------------------------
  * Path selection
@@ -346,13 +367,14 @@ static int __must_push_back(struct multipath *m)
 }
 
 static int map_io(struct multipath *m, struct request *clone,
-                 struct dm_mpath_io *mpio, unsigned was_queued)
+                 union map_info *map_context, unsigned was_queued)
 {
        int r = DM_MAPIO_REMAPPED;
        size_t nr_bytes = blk_rq_bytes(clone);
        unsigned long flags;
        struct pgpath *pgpath;
        struct block_device *bdev;
+       struct dm_mpath_io *mpio = map_context->ptr;
 
        spin_lock_irqsave(&m->lock, flags);
 
@@ -428,7 +450,6 @@ static void dispatch_queued_ios(struct multipath *m)
 {
        int r;
        unsigned long flags;
-       struct dm_mpath_io *mpio;
        union map_info *info;
        struct request *clone, *n;
        LIST_HEAD(cl);
@@ -441,16 +462,15 @@ static void dispatch_queued_ios(struct multipath *m)
                list_del_init(&clone->queuelist);
 
                info = dm_get_rq_mapinfo(clone);
-               mpio = info->ptr;
 
-               r = map_io(m, clone, mpio, 1);
+               r = map_io(m, clone, info, 1);
                if (r < 0) {
-                       mempool_free(mpio, m->mpio_pool);
+                       clear_mapinfo(m, info);
                        dm_kill_unmapped_request(clone, r);
                } else if (r == DM_MAPIO_REMAPPED)
                        dm_dispatch_request(clone);
                else if (r == DM_MAPIO_REQUEUE) {
-                       mempool_free(mpio, m->mpio_pool);
+                       clear_mapinfo(m, info);
                        dm_requeue_unmapped_request(clone);
                }
        }
@@ -736,8 +756,8 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
                return 0;
 
        m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
-       request_module("scsi_dh_%s", m->hw_handler_name);
-       if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
+       if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name),
+                                    "scsi_dh_%s", m->hw_handler_name)) {
                ti->error = "unknown hardware handler type";
                ret = -EINVAL;
                goto fail;
@@ -950,20 +970,16 @@ static int multipath_map(struct dm_target *ti, struct request *clone,
                         union map_info *map_context)
 {
        int r;
-       struct dm_mpath_io *mpio;
        struct multipath *m = (struct multipath *) ti->private;
 
-       mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
-       if (!mpio)
+       if (set_mapinfo(m, map_context) < 0)
                /* ENOMEM, requeue */
                return DM_MAPIO_REQUEUE;
-       memset(mpio, 0, sizeof(*mpio));
 
-       map_context->ptr = mpio;
        clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
-       r = map_io(m, clone, mpio, 0);
+       r = map_io(m, clone, map_context, 0);
        if (r < 0 || r == DM_MAPIO_REQUEUE)
-               mempool_free(mpio, m->mpio_pool);
+               clear_mapinfo(m, map_context);
 
        return r;
 }
@@ -1105,8 +1121,9 @@ static int switch_pg_num(struct multipath *m, const char *pgstr)
        struct priority_group *pg;
        unsigned pgnum;
        unsigned long flags;
+       char dummy;
 
-       if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum ||
+       if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
            (pgnum > m->nr_priority_groups)) {
                DMWARN("invalid PG number supplied to switch_pg_num");
                return -EINVAL;
@@ -1136,8 +1153,9 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed)
 {
        struct priority_group *pg;
        unsigned pgnum;
+       char dummy;
 
-       if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum ||
+       if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
            (pgnum > m->nr_priority_groups)) {
                DMWARN("invalid PG number supplied to bypass_pg");
                return -EINVAL;
@@ -1319,13 +1337,15 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
        struct path_selector *ps;
        int r;
 
+       BUG_ON(!mpio);
+
        r  = do_end_io(m, clone, error, mpio);
        if (pgpath) {
                ps = &pgpath->pg->ps;
                if (ps->type->end_io)
                        ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
        }
-       mempool_free(mpio, m->mpio_pool);
+       clear_mapinfo(m, map_context);
 
        return r;
 }