Quite a few fixes for DM's blk-mq support thanks to extra DM multipath

testing from Junichi Nomura and Bart Van Assche.
 
 Also fix a casting bug in dm_merge_bvec() that could cause only a single
 page to be added to a bio (Joe identified this while testing dm-cache
 writeback).
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Merge tag 'dm-4.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "Quite a few fixes for DM's blk-mq support thanks to extra DM multipath
  testing from Junichi Nomura and Bart Van Assche.

  Also fix a casting bug in dm_merge_bvec() that could cause only a
  single page to be added to a bio (Joe identified this while testing
  dm-cache writeback)"

* tag 'dm-4.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix casting bug in dm_merge_bvec()
  dm: fix reload failure of 0 path multipath mapping on blk-mq devices
  dm: fix false warning in free_rq_clone() for unmapped requests
  dm: requeue from blk-mq dm_mq_queue_rq() using BLK_MQ_RQ_QUEUE_BUSY
  dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error path
  dm: fix NULL pointer when clone_and_map_rq returns !DM_MAPIO_REMAPPED
  dm: run queue on re-queue
This commit is contained in:
Linus Torvalds 2015-05-29 14:39:24 -07:00
commit 0f1e5b5d19
3 changed files with 36 additions and 24 deletions

View file

@ -429,9 +429,11 @@ static int __multipath_map(struct dm_target *ti, struct request *clone,
/* blk-mq request-based interface */
*__clone = blk_get_request(bdev_get_queue(bdev),
rq_data_dir(rq), GFP_ATOMIC);
if (IS_ERR(*__clone))
if (IS_ERR(*__clone)) {
/* ENOMEM, requeue */
clear_mapinfo(m, map_context);
return r;
}
(*__clone)->bio = (*__clone)->biotail = NULL;
(*__clone)->rq_disk = bdev->bd_disk;
(*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT;

View file

@ -820,6 +820,12 @@ void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
}
EXPORT_SYMBOL(dm_consume_args);
static bool __table_type_request_based(unsigned table_type)
{
return (table_type == DM_TYPE_REQUEST_BASED ||
table_type == DM_TYPE_MQ_REQUEST_BASED);
}
static int dm_table_set_type(struct dm_table *t)
{
unsigned i;
@ -852,8 +858,7 @@ static int dm_table_set_type(struct dm_table *t)
* Determine the type from the live device.
* Default to bio-based if device is new.
*/
if (live_md_type == DM_TYPE_REQUEST_BASED ||
live_md_type == DM_TYPE_MQ_REQUEST_BASED)
if (__table_type_request_based(live_md_type))
request_based = 1;
else
bio_based = 1;
@ -903,7 +908,7 @@ static int dm_table_set_type(struct dm_table *t)
}
t->type = DM_TYPE_MQ_REQUEST_BASED;
} else if (hybrid && list_empty(devices) && live_md_type != DM_TYPE_NONE) {
} else if (list_empty(devices) && __table_type_request_based(live_md_type)) {
/* inherit live MD type */
t->type = live_md_type;
@ -925,10 +930,7 @@ struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
bool dm_table_request_based(struct dm_table *t)
{
unsigned table_type = dm_table_get_type(t);
return (table_type == DM_TYPE_REQUEST_BASED ||
table_type == DM_TYPE_MQ_REQUEST_BASED);
return __table_type_request_based(dm_table_get_type(t));
}
bool dm_table_mq_request_based(struct dm_table *t)

View file

@ -1082,13 +1082,11 @@ static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
dm_put(md);
}
static void free_rq_clone(struct request *clone, bool must_be_mapped)
static void free_rq_clone(struct request *clone)
{
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
WARN_ON_ONCE(must_be_mapped && !clone->q);
blk_rq_unprep_clone(clone);
if (md->type == DM_TYPE_MQ_REQUEST_BASED)
@ -1132,7 +1130,7 @@ static void dm_end_request(struct request *clone, int error)
rq->sense_len = clone->sense_len;
}
free_rq_clone(clone, true);
free_rq_clone(clone);
if (!rq->q->mq_ops)
blk_end_request_all(rq, error);
else
@ -1151,7 +1149,7 @@ static void dm_unprep_request(struct request *rq)
}
if (clone)
free_rq_clone(clone, false);
free_rq_clone(clone);
}
/*
@ -1164,6 +1162,7 @@ static void old_requeue_request(struct request *rq)
spin_lock_irqsave(q->queue_lock, flags);
blk_requeue_request(q, rq);
blk_run_queue_async(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
@ -1724,8 +1723,7 @@ static int dm_merge_bvec(struct request_queue *q,
struct mapped_device *md = q->queuedata;
struct dm_table *map = dm_get_live_table_fast(md);
struct dm_target *ti;
sector_t max_sectors;
int max_size = 0;
sector_t max_sectors, max_size = 0;
if (unlikely(!map))
goto out;
@ -1740,8 +1738,16 @@ static int dm_merge_bvec(struct request_queue *q,
max_sectors = min(max_io_len(bvm->bi_sector, ti),
(sector_t) queue_max_sectors(q));
max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
if (unlikely(max_size < 0)) /* this shouldn't _ever_ happen */
max_size = 0;
/*
* FIXME: this stop-gap fix _must_ be cleaned up (by passing a sector_t
* to the targets' merge function since it holds sectors not bytes).
* Just doing this as an interim fix for stable@ because the more
* comprehensive cleanup of switching to sector_t will impact every
* DM target that implements a ->merge hook.
*/
if (max_size > INT_MAX)
max_size = INT_MAX;
/*
* merge_bvec_fn() returns number of bytes
@ -1749,7 +1755,7 @@ static int dm_merge_bvec(struct request_queue *q,
* max is precomputed maximal io size
*/
if (max_size && ti->type->merge)
max_size = ti->type->merge(ti, bvm, biovec, max_size);
max_size = ti->type->merge(ti, bvm, biovec, (int) max_size);
/*
* If the target doesn't support merge method and some of the devices
* provided their merge_bvec method (we know this by looking for the
@ -1971,8 +1977,8 @@ static int map_request(struct dm_rq_target_io *tio, struct request *rq,
dm_kill_unmapped_request(rq, r);
return r;
}
if (IS_ERR(clone))
return DM_MAPIO_REQUEUE;
if (r != DM_MAPIO_REMAPPED)
return r;
if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
/* -ENOMEM */
ti->type->release_clone_rq(clone);
@ -2753,13 +2759,15 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
if (dm_table_get_type(map) == DM_TYPE_REQUEST_BASED) {
/* clone request is allocated at the end of the pdu */
tio->clone = (void *)blk_mq_rq_to_pdu(rq) + sizeof(struct dm_rq_target_io);
if (!clone_rq(rq, md, tio, GFP_ATOMIC))
return BLK_MQ_RQ_QUEUE_BUSY;
(void) clone_rq(rq, md, tio, GFP_ATOMIC);
queue_kthread_work(&md->kworker, &tio->work);
} else {
/* Direct call is fine since .queue_rq allows allocations */
if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE)
dm_requeue_unmapped_original_request(md, rq);
if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
/* Undo dm_start_request() before requeuing */
rq_completed(md, rq_data_dir(rq), false);
return BLK_MQ_RQ_QUEUE_BUSY;
}
}
return BLK_MQ_RQ_QUEUE_OK;