@@ -149,20 +149,9 @@ struct mapped_device {
int flush_error;
/*
- * Protect barrier_error from concurrent endio processing
- * in request-based dm.
- */
- spinlock_t barrier_error_lock;
- int barrier_error;
-
- /*
- * Processing queue (flush/barriers)
+ * Processing queue (flush)
*/
struct workqueue_struct *wq;
- struct work_struct barrier_work;
-
- /* A pointer to the currently processing pre/post flush request */
- struct request *flush_request;
/*
* The current mapping.
@@ -750,23 +739,6 @@ static void end_clone_bio(struct bio *clone, int error)
blk_update_request(tio->orig, 0, nr_bytes);
}
-static void store_barrier_error(struct mapped_device *md, int error)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&md->barrier_error_lock, flags);
- /*
- * Basically, the first error is taken, but:
- * -EOPNOTSUPP supersedes any I/O error.
- * Requeue request supersedes any I/O error but -EOPNOTSUPP.
- */
- if (!md->barrier_error || error == -EOPNOTSUPP ||
- (md->barrier_error != -EOPNOTSUPP &&
- error == DM_ENDIO_REQUEUE))
- md->barrier_error = error;
- spin_unlock_irqrestore(&md->barrier_error_lock, flags);
-}
-
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -804,13 +776,11 @@ static void free_rq_clone(struct request *clone)
static void dm_end_request(struct request *clone, int error)
{
int rw = rq_data_dir(clone);
- int run_queue = 1;
- bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER;
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) {
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
rq->errors = clone->errors;
rq->resid_len = clone->resid_len;
@@ -824,15 +794,8 @@ static void dm_end_request(struct request *clone, int error)
}
free_rq_clone(clone);
-
- if (unlikely(is_barrier)) {
- if (unlikely(error))
- store_barrier_error(md, error);
- run_queue = 0;
- } else
- blk_end_request_all(rq, error);
-
- rq_completed(md, rw, run_queue);
+ blk_end_request_all(rq, error);
+ rq_completed(md, rw, true);
}
static void dm_unprep_request(struct request *rq)
@@ -857,16 +820,6 @@ void dm_requeue_unmapped_request(struct request *clone)
struct request_queue *q = rq->q;
unsigned long flags;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- dm_end_request(clone, DM_ENDIO_REQUEUE);
- return;
- }
-
dm_unprep_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
@@ -956,19 +909,6 @@ static void dm_complete_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request. So can't use
- * softirq_done with the original.
- * Pass the clone to dm_done() directly in this special case.
- * It is safe (even if clone->q->queue_lock is held here)
- * because there is no I/O dispatching during the completion
- * of barrier clone.
- */
- dm_done(clone, error, true);
- return;
- }
-
tio->error = error;
rq->completion_data = clone;
blk_complete_request(rq);
@@ -985,17 +925,6 @@ void dm_kill_unmapped_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- BUG_ON(error > 0);
- dm_end_request(clone, error);
- return;
- }
-
rq->cmd_flags |= REQ_FAILED;
dm_complete_request(clone, error);
}
@@ -1536,14 +1465,6 @@ static int dm_request(struct request_queue *q, struct bio *bio)
return _dm_request(q, bio);
}
-static bool dm_rq_is_flush_request(struct request *rq)
-{
- if (rq->cmd_flags & REQ_FLUSH)
- return true;
- else
- return false;
-}
-
void dm_dispatch_request(struct request *rq)
{
int r;
@@ -1591,22 +1512,15 @@ static int setup_clone(struct request *clone, struct request *rq,
{
int r;
- if (dm_rq_is_flush_request(rq)) {
- blk_rq_init(NULL, clone);
- clone->cmd_type = REQ_TYPE_FS;
- clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
- } else {
- r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
- dm_rq_bio_constructor, tio);
- if (r)
- return r;
-
- clone->cmd = rq->cmd;
- clone->cmd_len = rq->cmd_len;
- clone->sense = rq->sense;
- clone->buffer = rq->buffer;
- }
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
@@ -1647,9 +1561,6 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
struct mapped_device *md = q->queuedata;
struct request *clone;
- if (unlikely(dm_rq_is_flush_request(rq)))
- return BLKPREP_OK;
-
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
@@ -1726,6 +1637,7 @@ static void dm_request_fn(struct request_queue *q)
struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
struct request *rq, *clone;
+ sector_t pos;
/*
* For suspend, check blk_queue_stopped() and increment
@@ -1738,15 +1650,14 @@ static void dm_request_fn(struct request_queue *q)
if (!rq)
goto plug_and_out;
- if (unlikely(dm_rq_is_flush_request(rq))) {
- BUG_ON(md->flush_request);
- md->flush_request = rq;
- blk_start_request(rq);
- queue_work(md->wq, &md->barrier_work);
- goto out;
- }
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ BUG_ON(!dm_target_is_valid(ti));
- ti = dm_table_find_target(map, blk_rq_pos(rq));
if (ti->type->busy && ti->type->busy(ti))
goto plug_and_out;
@@ -1917,7 +1828,6 @@ out:
static const struct block_device_operations dm_blk_dops;
static void dm_wq_work(struct work_struct *work);
-static void dm_rq_barrier_work(struct work_struct *work);
static void dm_init_md_queue(struct mapped_device *md)
{
@@ -1972,7 +1882,6 @@ static struct mapped_device *alloc_dev(int minor)
mutex_init(&md->suspend_lock);
mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
- spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
@@ -1995,7 +1904,6 @@ static struct mapped_device *alloc_dev(int minor)
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
- INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
@@ -2245,8 +2153,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- /* no flush support for request based dm yet */
- blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2483,73 +2389,6 @@ static void dm_queue_flush(struct mapped_device *md)
queue_work(md->wq, &md->work);
}
-static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr)
-{
- struct dm_rq_target_io *tio = clone->end_io_data;
-
- tio->info.target_request_nr = request_nr;
-}
-
-/* Issue barrier requests to targets and wait for their completion. */
-static int dm_rq_barrier(struct mapped_device *md)
-{
- int i, j;
- struct dm_table *map = dm_get_live_table(md);
- unsigned num_targets = dm_table_get_num_targets(map);
- struct dm_target *ti;
- struct request *clone;
-
- md->barrier_error = 0;
-
- for (i = 0; i < num_targets; i++) {
- ti = dm_table_get_target(map, i);
- for (j = 0; j < ti->num_flush_requests; j++) {
- clone = clone_rq(md->flush_request, md, GFP_NOIO);
- dm_rq_set_target_request_nr(clone, j);
- atomic_inc(&md->pending[rq_data_dir(clone)]);
- map_request(ti, clone, md);
- }
- }
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- dm_table_put(map);
-
- return md->barrier_error;
-}
-
-static void dm_rq_barrier_work(struct work_struct *work)
-{
- int error;
- struct mapped_device *md = container_of(work, struct mapped_device,
- barrier_work);
- struct request_queue *q = md->queue;
- struct request *rq;
- unsigned long flags;
-
- /*
- * Hold the md reference here and leave it at the last part so that
- * the md can't be deleted by device opener when the barrier request
- * completes.
- */
- dm_get(md);
-
- error = dm_rq_barrier(md);
-
- rq = md->flush_request;
- md->flush_request = NULL;
-
- if (error == DM_ENDIO_REQUEUE) {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
- } else
- blk_end_request_all(rq, error);
-
- blk_run_queue(q);
-
- dm_put(md);
-}
-
/*
* Swap in a new table, returning the old one for the caller to destroy.
*/
@@ -2686,9 +2525,8 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
up_write(&md->io_lock);
/*
- * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
- * can be kicked until md->queue is stopped. So stop md->queue before
- * flushing md->wq.
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
*/
if (dm_request_based(md))
stop_queue(md->queue);