diff options
| -rw-r--r-- | drivers/md/dm-table.c | 14 | ||||
| -rw-r--r-- | drivers/md/dm.c | 705 | ||||
| -rw-r--r-- | drivers/md/dm.h | 1 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 9 |
4 files changed, 725 insertions, 4 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 09a57113955e..c5f784419f23 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1080,6 +1080,20 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits) return r; } +int dm_table_any_busy_target(struct dm_table *t) +{ + unsigned i; + struct dm_target *ti; + + for (i = 0; i < t->num_targets; i++) { + ti = t->targets + i; + if (ti->type->busy && ti->type->busy(ti)) + return 1; + } + + return 0; +} + void dm_table_unplug_all(struct dm_table *t) { struct dm_dev_internal *dd; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f609793a92d0..be003e5fea3d 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -78,7 +78,7 @@ struct dm_rq_target_io { */ struct dm_rq_clone_bio_info { struct bio *orig; - struct request *rq; + struct dm_rq_target_io *tio; }; union map_info *dm_get_mapinfo(struct bio *bio) @@ -88,6 +88,14 @@ union map_info *dm_get_mapinfo(struct bio *bio) return NULL; } +union map_info *dm_get_rq_mapinfo(struct request *rq) +{ + if (rq && rq->end_io_data) + return &((struct dm_rq_target_io *)rq->end_io_data)->info; + return NULL; +} +EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); + #define MINOR_ALLOCED ((void *)-1) /* @@ -169,6 +177,12 @@ struct mapped_device { /* forced geometry settings */ struct hd_geometry geometry; + /* marker of flush suspend for request-based dm */ + struct request suspend_rq; + + /* For saving the address of __make_request for request based dm */ + make_request_fn *saved_make_request_fn; + /* sysfs handle */ struct kobject kobj; @@ -406,6 +420,26 @@ static void free_tio(struct mapped_device *md, struct dm_target_io *tio) mempool_free(tio, md->tio_pool); } +static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md) +{ + return mempool_alloc(md->tio_pool, GFP_ATOMIC); +} + +static void free_rq_tio(struct dm_rq_target_io *tio) +{ + mempool_free(tio, tio->md->tio_pool); +} + +static struct dm_rq_clone_bio_info *alloc_bio_info(struct mapped_device *md) +{ + return mempool_alloc(md->io_pool, GFP_ATOMIC); +} + +static void free_bio_info(struct dm_rq_clone_bio_info *info) +{ + mempool_free(info, info->tio->md->io_pool); +} + static void start_io_acct(struct dm_io *io) { struct mapped_device *md = io->md; @@ -615,6 +649,262 @@ static void clone_endio(struct bio *bio, int error) dec_pending(io, error); } +/* + * Partial completion handling for request-based dm + */ +static void end_clone_bio(struct bio *clone, int error) +{ + struct dm_rq_clone_bio_info *info = clone->bi_private; + struct dm_rq_target_io *tio = info->tio; + struct bio *bio = info->orig; + unsigned int nr_bytes = info->orig->bi_size; + + bio_put(clone); + + if (tio->error) + /* + * An error has already been detected on the request. + * Once error occurred, just let clone->end_io() handle + * the remainder. + */ + return; + else if (error) { + /* + * Don't notice the error to the upper layer yet. + * The error handling decision is made by the target driver, + * when the request is completed. + */ + tio->error = error; + return; + } + + /* + * I/O for the bio successfully completed. + * Notice the data completion to the upper layer. + */ + + /* + * bios are processed from the head of the list. + * So the completing bio should always be rq->bio. + * If it's not, something wrong is happening. + */ + if (tio->orig->bio != bio) + DMERR("bio completion is going in the middle of the request"); + + /* + * Update the original request. + * Do not use blk_end_request() here, because it may complete + * the original request before the clone, and break the ordering. + */ + blk_update_request(tio->orig, 0, nr_bytes); +} + +/* + * 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. + * Or do dm_get() before calling this function and dm_put() later. + */ +static void rq_completed(struct mapped_device *md, int run_queue) +{ + int wakeup_waiters = 0; + struct request_queue *q = md->queue; + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + if (!queue_in_flight(q)) + wakeup_waiters = 1; + spin_unlock_irqrestore(q->queue_lock, flags); + + /* nudge anyone waiting on suspend queue */ + if (wakeup_waiters) + wake_up(&md->wait); + + if (run_queue) + blk_run_queue(q); + + /* + * dm_put() must be at the end of this function. See the comment above + */ + dm_put(md); +} + +static void dm_unprep_request(struct request *rq) +{ + struct request *clone = rq->special; + struct dm_rq_target_io *tio = clone->end_io_data; + + rq->special = NULL; + rq->cmd_flags &= ~REQ_DONTPREP; + + blk_rq_unprep_clone(clone); + free_rq_tio(tio); +} + +/* + * Requeue the original request of a clone. + */ +void dm_requeue_unmapped_request(struct request *clone) +{ + struct dm_rq_target_io *tio = clone->end_io_data; + struct mapped_device *md = tio->md; + struct request *rq = tio->orig; + struct request_queue *q = rq->q; + unsigned long flags; + + dm_unprep_request(rq); + + spin_lock_irqsave(q->queue_lock, flags); + if (elv_queue_empty(q)) + blk_plug_device(q); + blk_requeue_request(q, rq); + spin_unlock_irqrestore(q->queue_lock, flags); + + rq_completed(md, 0); +} +EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request); + +static void __stop_queue(struct request_queue *q) +{ + blk_stop_queue(q); +} + +static void stop_queue(struct request_queue *q) +{ + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + __stop_queue(q); + spin_unlock_irqrestore(q->queue_lock, flags); +} + +static void __start_queue(struct request_queue *q) +{ + if (blk_queue_stopped(q)) + blk_start_queue(q); +} + +static void start_queue(struct request_queue *q) +{ + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + __start_queue(q); + spin_unlock_irqrestore(q->queue_lock, flags); +} + +/* + * Complete the clone and the original request. + * Must be called without queue lock. + */ +static void dm_end_request(struct request *clone, int error) +{ + struct dm_rq_target_io *tio = clone->end_io_data; + struct mapped_device *md = tio->md; + struct request *rq = tio->orig; + + if (blk_pc_request(rq)) { + rq->errors = clone->errors; + rq->resid_len = clone->resid_len; + + if (rq->sense) + /* + * We are using the sense buffer of the original + * request. + * So setting the length of the sense data is enough. + */ + rq->sense_len = clone->sense_len; + } + + BUG_ON(clone->bio); + free_rq_tio(tio); + + blk_end_request_all(rq, error); + + rq_completed(md, 1); +} + +/* + * Request completion handler for request-based dm + */ +static void dm_softirq_done(struct request *rq) +{ + struct request *clone = rq->completion_data; + struct dm_rq_target_io *tio = clone->end_io_data; + dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io; + int error = tio->error; + + if (!(rq->cmd_flags & REQ_FAILED) && rq_end_io) + error = rq_end_io(tio->ti, clone, error, &tio->info); + + if (error <= 0) + /* The target wants to complete the I/O */ + dm_end_request(clone, error); + else if (error == DM_ENDIO_INCOMPLETE) + /* The target will handle the I/O */ + return; + else if (error == DM_ENDIO_REQUEUE) + /* The target wants to requeue the I/O */ + dm_requeue_unmapped_request(clone); + else { + DMWARN("unimplemented target endio return value: %d", error); + BUG(); + } +} + +/* + * Complete the clone and the original request with the error status + * through softirq context. + */ +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; + + tio->error = error; + rq->completion_data = clone; + blk_complete_request(rq); +} + +/* + * Complete the not-mapped clone and the original request with the error status + * through softirq context. + * Target's rq_end_io() function isn't called. + * This may be used when the target's map_rq() function fails. + */ +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; + + rq->cmd_flags |= REQ_FAILED; + dm_complete_request(clone, error); +} +EXPORT_SYMBOL_GPL(dm_kill_unmapped_request); + +/* + * Called with the queue lock held + */ +static void end_clone_request(struct request *clone, int error) +{ + /* + * For just cleaning up the information of the queue in which + * the clone was dispatched. + * The clone is *NOT* freed actually here because it is alloced from + * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags. + */ + __blk_put_request(clone->q, clone); + + /* + * Actual request completion is done in a softirq context which doesn't + * hold the queue lock. Otherwise, deadlock could occur because: + * - another request may be submitted by the upper level driver + * of the stacking during the completion + * - the submission which requires queue lock may be done + * against this queue + */ + dm_complete_request(clone, error); +} + static sector_t max_io_len(struct mapped_device *md, sector_t sector, struct dm_target *ti) { @@ -998,7 +1288,7 @@ out: * The request function that just remaps the bio built up by * dm_merge_bvec. */ -static int dm_request(struct request_queue *q, struct bio *bio) +static int _dm_request(struct request_queue *q, struct bio *bio) { int rw = bio_data_dir(bio); struct mapped_device *md = q->queuedata; @@ -1035,12 +1325,274 @@ static int dm_request(struct request_queue *q, struct bio *bio) return 0; } +static int dm_make_request(struct request_queue *q, struct bio *bio) +{ + struct mapped_device *md = q->queuedata; + + if (unlikely(bio_barrier(bio))) { + bio_endio(bio, -EOPNOTSUPP); + return 0; + } + + return md->saved_make_request_fn(q, bio); /* call __make_request() */ +} + +static int dm_request_based(struct mapped_device *md) +{ + return blk_queue_stackable(md->queue); +} + +static int dm_request(struct request_queue *q, struct bio *bio) +{ + struct mapped_device *md = q->queuedata; + + if (dm_request_based(md)) + return dm_make_request(q, bio); + + return _dm_request(q, bio); +} + +void dm_dispatch_request(struct request *rq) +{ + int r; + + if (blk_queue_io_stat(rq->q)) + rq->cmd_flags |= REQ_IO_STAT; + + rq->start_time = jiffies; + r = blk_insert_cloned_request(rq->q, rq); + if (r) + dm_complete_request(rq, r); +} +EXPORT_SYMBOL_GPL(dm_dispatch_request); + +static void dm_rq_bio_destructor(struct bio *bio) +{ + struct dm_rq_clone_bio_info *info = bio->bi_private; + struct mapped_device *md = info->tio->md; + + free_bio_info(info); + bio_free(bio, md->bs); +} + +static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, + void *data) +{ + struct dm_rq_target_io *tio = data; + struct mapped_device *md = tio->md; + struct dm_rq_clone_bio_info *info = alloc_bio_info(md); + + if (!info) + return -ENOMEM; + + info->orig = bio_orig; + info->tio = tio; + bio->bi_end_io = end_clone_bio; + bio->bi_private = info; + bio->bi_destructor = dm_rq_bio_destructor; + + return 0; +} + +static int setup_clone(struct request *clone, struct request *rq, + struct dm_rq_target_io *tio) +{ + int 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; + + return 0; +} + +static int dm_rq_flush_suspending(struct mapped_device *md) +{ + return !md->suspend_rq.special; +} + +/* + * Called with the queue lock held. + */ +static int dm_prep_fn(struct request_queue *q, struct request *rq) +{ + struct mapped_device *md = q->queuedata; + struct dm_rq_target_io *tio; + struct request *clone; + + if (unlikely(rq == &md->suspend_rq)) { + if (dm_rq_flush_suspending(md)) + return BLKPREP_OK; + else + /* The flush suspend was interrupted */ + return BLKPREP_KILL; + } + + if (unlikely(rq->special)) { + DMWARN("Already has something in rq->special."); + return BLKPREP_KILL; + } + + tio = alloc_rq_tio(md); /* Only one for each original request */ + if (!tio) + /* -ENOMEM */ + return BLKPREP_DEFER; + + tio->md = md; + tio->ti = NULL; + tio->orig = rq; + tio->error = 0; + memset(&tio->info, 0, sizeof(tio->info)); + + clone = &tio->clone; + if (setup_clone(clone, rq, tio)) { + /* -ENOMEM */ + free_rq_tio(tio); + return BLKPREP_DEFER; + } + + rq->special = clone; + rq->cmd_flags |= REQ_DONTPREP; + + return BLKPREP_OK; +} + +static void map_request(struct dm_target *ti, struct request *rq, + struct mapped_device *md) +{ + int r; + struct request *clone = rq->special; + struct dm_rq_target_io *tio = clone->end_io_data; + + /* + * Hold the md reference here for the in-flight I/O. + * We can't rely on the reference count by device opener, + * because the device may be closed during the request completion + * when all bios are completed. + * See the comment in rq_completed() too. + */ + dm_get(md); + + tio->ti = ti; + r = ti->type->map_rq(ti, clone, &tio->info); + switch (r) { + case DM_MAPIO_SUBMITTED: + /* The target has taken the I/O to submit by itself later */ + break; + case DM_MAPIO_REMAPPED: + /* The target has remapped the I/O so dispatch it */ + dm_dispatch_request(clone); + break; + case DM_MAPIO_REQUEUE: + /* The target wants to requeue the I/O */ + dm_requeue_unmapped_request(clone); + break; + default: + if (r > 0) { + DMWARN("unimplemented target map return value: %d", r); + BUG(); + } + + /* The target wants to complete the I/O */ + dm_kill_unmapped_request(clone, r); + break; + } +} + +/* + * q->request_fn for request-based dm. + * Called with the queue lock held. + */ +static void dm_request_fn(struct request_queue *q) +{ + struct mapped_device *md = q->queuedata; + struct dm_table *map = dm_get_table(md); + struct dm_target *ti; + struct request *rq; + + /* + * For noflush suspend, check blk_queue_stopped() to immediately + * quit I/O dispatching. + */ + while (!blk_queue_plugged(q) && !blk_queue_stopped(q)) { + rq = blk_peek_request(q); + if (!rq) + goto plug_and_out; + + if (unlikely(rq == &md->suspend_rq)) { /* Flush suspend maker */ + if (queue_in_flight(q)) + /* Not quiet yet. Wait more */ + goto plug_and_out; + + /* This device should be quiet now */ + __stop_queue(q); + blk_start_request(rq); + __blk_end_request_all(rq, 0); + wake_up(&md->wait); + goto out; + } + + ti = dm_table_find_target(map, blk_rq_pos(rq)); + if (ti->type->busy && ti->type->busy(ti)) + goto plug_and_out; + + blk_start_request(rq); + spin_unlock(q->queue_lock); + map_request(ti, rq, md); + spin_lock_irq(q->queue_lock); + } + + goto out; + +plug_and_out: + if (!elv_queue_empty(q)) + /* Some requests still remain, retry later */ + blk_plug_device(q); + +out: + dm_table_put(map); + + return; +} + +int dm_underlying_device_busy(struct request_queue *q) +{ + return blk_lld_busy(q); +} +EXPORT_SYMBOL_GPL(dm_underlying_device_busy); + +static int dm_lld_busy(struct request_queue *q) +{ + int r; + struct mapped_device *md = q->queuedata; + struct dm_table *map = dm_get_table(md); + + if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) + r = 1; + else + r = dm_table_any_busy_target(map); + + dm_table_put(map); + + return r; +} + static void dm_unplug_all(struct request_queue *q) { struct mapped_device *md = q->queuedata; struct dm_table *map = dm_get_table(md); if (map) { + if (dm_request_based(md)) + generic_unplug_device(q); + dm_table_unplug_all(map); dm_table_put(map); } @@ -1055,7 +1607,16 @@ static int dm_any_congested(void *congested_data, int bdi_bits) if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { map = dm_get_table(md); if (map) { - r = dm_table_any_congested(map, bdi_bits); + /* + * Request-based dm cares about only own queue for + * the query about congestion status of request_queue + */ + if (dm_request_based(md)) + r = md->queue->backing_dev_info.state & + bdi_bits; + else + r = dm_table_any_congested(map, bdi_bits); + dm_table_put(map); } } @@ -1458,6 +2019,8 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible) { int r = 0; DECLARE_WAITQUEUE(wait, current); + struct request_queue *q = md->queue; + unsigned long flags; dm_unplug_all(md->queue); @@ -1467,7 +2030,14 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible) set_current_state(interruptible); smp_mb(); - if (!atomic_read(&md->pending)) + if (dm_request_based(md)) { + spin_lock_irqsave(q->queue_lock, flags); + if (!queue_in_flight(q) && blk_queue_stopped(q)) { + spin_unlock_irqrestore(q->queue_lock, flags); + break; + } + spin_unlock_irqrestore(q->queue_lock, flags); + } else if (!atomic_read(&md->pending)) break; if (interruptible == TASK_INTERRUPTIBLE && @@ -1584,6 +2154,67 @@ out: return r; } +static void dm_rq_invalidate_suspend_marker(struct mapped_device *md) +{ + md->suspend_rq.special = (void *)0x1; +} + +static void dm_rq_abort_suspend(struct mapped_device *md, int noflush) +{ + struct request_queue *q = md->queue; + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + if (!noflush) + dm_rq_invalidate_suspend_marker(md); + __start_queue(q); + spin_unlock_irqrestore(q->queue_lock, flags); +} + +static void dm_rq_start_suspend(struct mapped_device *md, int noflush) +{ + struct request *rq = &md->suspend_rq; + struct request_queue *q = md->queue; + + if (noflush) + stop_queue(q); + else { + blk_rq_init(q, rq); + blk_insert_request(q, rq, 0, NULL); + } +} + +static int dm_rq_suspend_available(struct mapped_device *md, int noflush) +{ + int r = 1; + struct request *rq = &md->suspend_rq; + struct request_queue *q = md->queue; + unsigned long flags; + + if (noflush) + return r; + + /* The marker must be protected by queue lock if it is in use */ + spin_lock_irqsave(q->queue_lock, flags); + if (unlikely(rq->ref_count)) { + /* + * This can happen, when the previous flush suspend was + * interrupted, the marker is still in the queue and + * this flush suspend has been invoked, because we don't + * remove the marker at the time of suspend interruption. + * We have only one marker per mapped_device, so we can't + * start another flush suspend while it is in use. + */ + BUG_ON(!rq->special); /* The marker should be invalidated */ + DMWARN("Invalidating the previous flush suspend is still in" + " progress. Please retry later."); + r = 0; + } + spin_unlock_irqrestore(q->queue_lock, flags); + + return r; +} + /* * Functions to lock and unlock any filesystem running on the * device. @@ -1623,6 +2254,53 @@ static void unlock_fs(struct mapped_device *md) * dm_bind_table, dm_suspend must be called to flush any in * flight bios and ensure that any further io gets deferred. */ +/* + * Suspend mechanism in request-based dm. + * + * After the suspend starts, further incoming requests are kept in + * the request_queue and deferred. + * Remaining requests in the request_queue at the start of suspend are flushed + * if it is flush suspend. + * The suspend completes when the following conditions have been satisfied, + * so wait for it: + * 1. q->in_flight is 0 (which means no in_flight request) + * 2. queue has been stopped (which means no request dispatching) + * + * + * Noflush suspend + * --------------- + * Noflush suspend doesn't need to dispatch remaining requests. + * So stop the queue immediately. Then, wait for all in_flight requests + * to be completed or requeued. + * + * To abort noflush suspend, start the queue. + * + * + * Flush suspend + * ------------- + * Flush suspend needs to dispatch remaining requests. So stop the queue + * after the remaining requests are completed. (Requeued request must be also + * re-dispatched and completed. Until then, we can't stop the queue.) + * + * During flushing the remaining requests, further incoming requests are also + * inserted to the same queue. To distinguish which requests are to be + * flushed, we insert a marker request to the queue at the time of starting + * flush suspend, like a barrier. + * The dispatching is blocked when the marker is found on the top of the queue. + * And the queue is stopped when all in_flight requests are completed, since + * that means the remaining requests are completely flushed. + * Then, the marker is removed from the queue. + * + * To abort flush suspend, we also need to take care of the marker, not only + * starting the queue. + * We don't remove the marker forcibly from the queue since it's against + * the block-layer manner. Instead, we put a invalidated mark on the marker. + * When the invalidated marker is found on the top of the queue, it is + * immediately removed from the queue, so it doesn't block dispatching. + * Because we have only one marker per mapped_device, we can't start another + * flush suspend until the invalidated marker is removed from the queue. + * So fail and return with -EBUSY in such a case. + */ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) { struct dm_table *map = NULL; @@ -1637,6 +2315,11 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) goto out_unlock; } + if (dm_request_based(md) && !dm_rq_suspend_available(md, noflush)) { + r = -EBUSY; + goto out_unlock; + } + map = dm_get_table(md); /* @@ -1682,6 +2365,9 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) flush_workqueue(md->wq); + if (dm_request_based(md)) + dm_rq_start_suspend(md, noflush); + /* * At this point no more requests are entering target request routines. * We call dm_wait_for_completion to wait for all existing requests @@ -1698,6 +2384,9 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) if (r < 0) { dm_queue_flush(md); + if (dm_request_based(md)) + dm_rq_abort_suspend(md, noflush); + unlock_fs(md); goto out; /* pushback list is already flushed, so skip flush */ } @@ -1739,6 +2428,14 @@ int dm_resume(struct mapped_device *md) dm_queue_flush(md); + /* + * Flushing deferred I/Os must be done after targets are resumed + * so that mapping of targets can work correctly. + * Request-based dm is queueing the deferred I/Os in its request_queue. + */ + if (dm_request_based(md)) + start_queue(md->queue); + unlock_fs(md); clear_bit(DMF_SUSPENDED, &md->flags); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 604e85caadf6..8dcabb1caff1 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -50,6 +50,7 @@ void dm_table_presuspend_targets(struct dm_table *t); void dm_table_postsuspend_targets(struct dm_table *t); int dm_table_resume_targets(struct dm_table *t); int dm_table_any_congested(struct dm_table *t, int bdi_bits); +int dm_table_any_busy_target(struct dm_table *t); /* * To check the return value from dm_table_find_target(). diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index e6bf3b8c7bf2..0d6310657f32 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -234,6 +234,7 @@ struct gendisk *dm_disk(struct mapped_device *md); int dm_suspended(struct mapped_device *md); int dm_noflush_suspending(struct dm_target *ti); union map_info *dm_get_mapinfo(struct bio *bio); +union map_info *dm_get_rq_mapinfo(struct request *rq); /* * Geometry functions. @@ -396,4 +397,12 @@ static inline unsigned long to_bytes(sector_t n) return (n << SECTOR_SHIFT); } +/*----------------------------------------------------------------- + * Helper for block layer and dm core operations + *---------------------------------------------------------------*/ +void dm_dispatch_request(struct request *rq); +void dm_requeue_unmapped_request(struct request *rq); +void dm_kill_unmapped_request(struct request *rq, int error); +int dm_underlying_device_busy(struct request_queue *q); + #endif /* _LINUX_DEVICE_MAPPER_H */ |