From c37366742baa2bb3225be507d283baef151c5f8a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 12 Mar 2018 20:30:43 -0400 Subject: [PATCH 1/3] dm mpath: fix uninitialized 'pg_init_wait' waitqueue_head NULL pointer Initialize all the scsi_dh related 'struct multipath' members regardless of whether a scsi_dh is in use or not. The subtle (and fragile) SCSI-assuming legacy code clearly needs further decoupling from non-SCSI (and/or developer understanding). Fixes: 8d47e65948dd ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks") Reported-by: Bart Van Assche Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 3fde9e9faddd..87c404eebe9f 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -223,6 +223,16 @@ static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m) dm_table_set_type(ti->table, m->queue_mode); + /* + * Init fields that are only used when a scsi_dh is attached + * - must do this unconditionally (really doesn't hurt non-SCSI uses) + */ + set_bit(MPATHF_QUEUE_IO, &m->flags); + atomic_set(&m->pg_init_in_progress, 0); + atomic_set(&m->pg_init_count, 0); + m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; + init_waitqueue_head(&m->pg_init_wait); + return 0; } @@ -331,7 +341,6 @@ static void __switch_pg(struct multipath *m, struct priority_group *pg) set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); set_bit(MPATHF_QUEUE_IO, &m->flags); } else { - /* FIXME: not needed if no scsi_dh is attached */ clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); clear_bit(MPATHF_QUEUE_IO, &m->flags); } @@ -823,16 +832,6 @@ retain: */ kfree(m->hw_handler_name); m->hw_handler_name = attached_handler_name; - - /* - * Init fields that are only used when a scsi_dh is attached - */ - if (!test_and_set_bit(MPATHF_QUEUE_IO, &m->flags)) { - atomic_set(&m->pg_init_in_progress, 0); - atomic_set(&m->pg_init_count, 0); - m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; - init_waitqueue_head(&m->pg_init_wait); - } } } From e8f74a0f00113d74ac18d6de13096f9e2f95618a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 12 Mar 2018 19:49:25 -0400 Subject: [PATCH 2/3] dm mpath: eliminate need to use scsi_device_from_queue Instead of scsi_device_from_queue(), use scsi_dh_attached_handler_name() -- whose implementation uses scsi_device_from_queue() to avoid trying to access SCSI-specific resources from non-SCSI devices. Fixes buildbot reported issue when CONFIG_SCSI isn't set: ERROR: "scsi_device_from_queue" [drivers/md/dm-multipath.ko] undefined! Fixes: 8d47e65948dd ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks") Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 87c404eebe9f..2481c4794ed6 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include #include @@ -805,15 +804,14 @@ static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, return 0; } -static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, char **error) +static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, + const char *attached_handler_name, char **error) { struct request_queue *q = bdev_get_queue(bdev); - const char *attached_handler_name; int r; if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) { retain: - attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); if (attached_handler_name) { /* * Clear any hw_handler_params associated with a @@ -867,7 +865,8 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps int r; struct pgpath *p; struct multipath *m = ti->private; - struct scsi_device *sdev; + struct request_queue *q; + const char *attached_handler_name; /* we need at least a path arg */ if (as->argc < 1) { @@ -886,11 +885,11 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps goto bad; } - sdev = scsi_device_from_queue(bdev_get_queue(p->path.dev->bdev)); - if (sdev) { - put_device(&sdev->sdev_gendev); + q = bdev_get_queue(p->path.dev->bdev); + attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); + if (attached_handler_name) { INIT_DELAYED_WORK(&p->activate_path, activate_path_work); - r = setup_scsi_dh(p->path.dev->bdev, m, &ti->error); + r = setup_scsi_dh(p->path.dev->bdev, m, attached_handler_name, &ti->error); if (r) { dm_put_device(ti, p->path.dev); goto bad; From 8c5c147339d2e201108169327b1f99aa6d57d2cd Mon Sep 17 00:00:00 2001 From: Steffen Maier Date: Wed, 14 Mar 2018 15:33:06 +0100 Subject: [PATCH 3/3] dm mpath: fix passing integrity data After v4.12 commit e2460f2a4bc7 ("dm: mark targets that pass integrity data"), dm-multipath, e.g. on DIF+DIX SCSI disk paths, does not support block integrity any more. So add it to the whitelist. This is also a pre-requisite to use block integrity with other dm layer(s) on top of multipath, such as kpartx partitions (dm-linear) or LVM. Also, bump target version to reflect this fix. Fixes: e2460f2a4bc7 ("dm: mark targets that pass integrity data") Cc: #4.12+ Bisected-by: Fedor Loshakov Signed-off-by: Steffen Maier Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 2481c4794ed6..a05a560d3cba 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -2020,8 +2020,9 @@ static int multipath_busy(struct dm_target *ti) *---------------------------------------------------------------*/ static struct target_type multipath_target = { .name = "multipath", - .version = {1, 12, 0}, - .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE, + .version = {1, 13, 0}, + .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE | + DM_TARGET_PASSES_INTEGRITY, .module = THIS_MODULE, .ctr = multipath_ctr, .dtr = multipath_dtr,