These changes are the raw update to linux-4.4.6-rt14. Kernel sources

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

diff --git a/kernel/drivers/md/dm-mpath.c b/kernel/drivers/md/dm-mpath.c
index eff7bdd..cfa29f5 100644 (file)
--- a/kernel/drivers/md/dm-mpath.c
+++ b/kernel/drivers/md/dm-mpath.c
@@ -159,12 +159,9 @@ static struct priority_group *alloc_priority_group(void)
 static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
 {
        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);
                free_pgpath(pgpath);
        }
@@ -580,6 +577,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
                q = bdev_get_queue(p->path.dev->bdev);
 
        if (m->retain_attached_hw_handler) {
+retain:
                attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
                if (attached_handler_name) {
                        /*
@@ -599,20 +597,14 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
        }
 
        if (m->hw_handler_name) {
-               /*
-                * Increments scsi_dh reference, even when using an
-                * already-attached handler.
-                */
                r = scsi_dh_attach(q, m->hw_handler_name);
                if (r == -EBUSY) {
-                       /*
-                        * Already attached to different hw_handler:
-                        * try to reattach with correct one.
-                        */
-                       scsi_dh_detach(q);
-                       r = scsi_dh_attach(q, m->hw_handler_name);
-               }
+                       char b[BDEVNAME_SIZE];
 
+                       printk(KERN_INFO "dm-mpath: retaining handler on device %s\n",
+                               bdevname(p->path.dev->bdev, b));
+                       goto retain;
+               }
                if (r < 0) {
                        ti->error = "error attaching hardware handler";
                        dm_put_device(ti, p->path.dev);
@@ -624,7 +616,6 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
                        if (r < 0) {
                                ti->error = "unable to set hardware "
                                                        "handler parameters";
-                               scsi_dh_detach(q);
                                dm_put_device(ti, p->path.dev);
                                goto bad;
                        }
@@ -734,12 +725,6 @@ 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);
-       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;
-       }
 
        if (hw_argc > 1) {
                char *p;
@@ -1548,49 +1533,38 @@ out:
        return r;
 }
 
-static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
-                          unsigned long arg)
+static int multipath_prepare_ioctl(struct dm_target *ti,
+               struct block_device **bdev, fmode_t *mode)
 {
        struct multipath *m = ti->private;
-       struct pgpath *pgpath;
-       struct block_device *bdev;
-       fmode_t mode;
        unsigned long flags;
        int r;
 
-       bdev = NULL;
-       mode = 0;
-       r = 0;
-
        spin_lock_irqsave(&m->lock, flags);
 
        if (!m->current_pgpath)
                __choose_pgpath(m, 0);
 
-       pgpath = m->current_pgpath;
-
-       if (pgpath) {
-               bdev = pgpath->path.dev->bdev;
-               mode = pgpath->path.dev->mode;
+       if (m->current_pgpath) {
+               if (!m->queue_io) {
+                       *bdev = m->current_pgpath->path.dev->bdev;
+                       *mode = m->current_pgpath->path.dev->mode;
+                       r = 0;
+               } else {
+                       /* pg_init has not started or completed */
+                       r = -ENOTCONN;
+               }
+       } else {
+               /* No path is available */
+               if (m->queue_if_no_path)
+                       r = -ENOTCONN;
+               else
+                       r = -EIO;
        }
 
-       if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path))
-               r = -ENOTCONN;
-       else if (!bdev)
-               r = -EIO;
-
        spin_unlock_irqrestore(&m->lock, flags);
 
-       /*
-        * Only pass ioctls through if the device sizes match exactly.
-        */
-       if (!bdev || ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) {
-               int err = scsi_verify_blk_ioctl(NULL, cmd);
-               if (err)
-                       r = err;
-       }
-
-       if (r == -ENOTCONN && !fatal_signal_pending(current)) {
+       if (r == -ENOTCONN) {
                spin_lock_irqsave(&m->lock, flags);
                if (!m->current_pg) {
                        /* Path status changed, redo selection */
@@ -1602,7 +1576,12 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
                dm_table_run_md_queue_async(m->ti->table);
        }
 
-       return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+       /*
+        * Only pass ioctls through if the device sizes match exactly.
+        */
+       if (!r && ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
+               return 1;
+       return r;
 }
 
 static int multipath_iterate_devices(struct dm_target *ti,
@@ -1705,7 +1684,7 @@ out:
  *---------------------------------------------------------------*/
 static struct target_type multipath_target = {
        .name = "multipath",
-       .version = {1, 9, 0},
+       .version = {1, 10, 0},
        .module = THIS_MODULE,
        .ctr = multipath_ctr,
        .dtr = multipath_dtr,
@@ -1718,7 +1697,7 @@ static struct target_type multipath_target = {
        .resume = multipath_resume,
        .status = multipath_status,
        .message = multipath_message,
-       .ioctl  = multipath_ioctl,
+       .prepare_ioctl = multipath_prepare_ioctl,
        .iterate_devices = multipath_iterate_devices,
        .busy = multipath_busy,
 };