diff options
| author | Christoph Hellwig <hch@lst.de> | 2015-08-27 14:16:54 +0200 |
|---|---|---|
| committer | James Bottomley <JBottomley@Odin.com> | 2015-08-28 13:14:54 -0700 |
| commit | 1bab0de0274fbe8c8ac92179e6705584c55ed169 (patch) | |
| tree | 3a2bbd51706e6ec0a279cbc0011d996de7320aa7 /drivers/md | |
| parent | 36dd5acd196574d41de3e81d8264df475bbb7123 (diff) | |
| download | linux-1bab0de0274fbe8c8ac92179e6705584c55ed169.tar.bz2 | |
dm-mpath, scsi_dh: don't let dm detach device handlers
While allowing dm-mpath to attach device handlers is a functionality we need
for backwards compatibility reason there is no reason to reference count
them and detach them if dm-mpath stops using the device for some reason.
If the device handler works for the given device it can just stay attached,
and we can take the retain_hw_handler codepath.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-mpath.c | 21 |
1 files changed, 6 insertions, 15 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index eff7bdd7731d..a9f58fdb5d69 100644 --- a/drivers/md/dm-mpath.c +++ b/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; } |