A DM device's first table_load will establish the immutable md->type. But md->queue initialization, based on md->type, may fail at that time (if blk_init_allocated_queue cannot allocate memory). Therefore any subsequent table_load must (re)try dm_setup_md_queue independent of establishing md->type. Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- drivers/md/dm-ioctl.c | 18 +++++++++--------- drivers/md/dm.c | 3 ++- 2 files changed, 11 insertions(+), 10 deletions(-) NOTE: coping with blk_init_allocated_queue failure was mistakenly "optimized" away during review of the patch that introduced dm_setup_md_queue: https://www.redhat.com/archives/dm-devel/2010-May/msg00173.html Index: linux-2.6/drivers/md/dm-ioctl.c =================================================================== --- linux-2.6.orig/drivers/md/dm-ioctl.c +++ linux-2.6/drivers/md/dm-ioctl.c @@ -1181,15 +1181,6 @@ static int table_load(struct dm_ioctl *p if (dm_get_md_type(md) == DM_TYPE_NONE) { /* initial table load, set md's type based on table's type */ dm_set_md_type(md, dm_table_get_type(t)); - - /* setup md->queue to reflect md's type (may block) */ - r = dm_setup_md_queue(md); - if (r) { - DMWARN("unable to setup device queue for this table."); - dm_table_destroy(t); - dm_unlock_md_type(md); - goto out; - } } else if (dm_get_md_type(md) != dm_table_get_type(t)) { DMWARN("can't change device type after initial table load."); dm_table_destroy(t); @@ -1197,6 +1188,15 @@ static int table_load(struct dm_ioctl *p r = -EINVAL; goto out; } + + /* setup md->queue to reflect md's type (may block) */ + r = dm_setup_md_queue(md); + if (r) { + DMWARN("unable to setup device queue for this table."); + dm_table_destroy(t); + dm_unlock_md_type(md); + goto out; + } dm_unlock_md_type(md); /* stage inactive table */ Index: linux-2.6/drivers/md/dm.c =================================================================== --- linux-2.6.orig/drivers/md/dm.c +++ linux-2.6/drivers/md/dm.c @@ -2164,7 +2164,8 @@ static int dm_init_request_based_queue(s { struct request_queue *q = NULL; - BUG_ON(md->queue->elevator); + if (unlikely(md->queue->elevator)) + return 1; /* Fully initialize the queue */ q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
