atomic_t io_count;
struct bio *bio;
unsigned long start_time;
+ spinlock_t endio_lock;
};
/*
int barrier_error;
/*
+ * Protect barrier_error from concurrent endio processing
+ * in request-based dm.
+ */
+ spinlock_t barrier_error_lock;
+
+ /*
* Processing queue (flush/barriers)
*/
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.
/* 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;
dm_target_init,
dm_linear_init,
dm_stripe_init,
+ dm_io_init,
dm_kcopyd_init,
dm_interface_init,
};
dm_target_exit,
dm_linear_exit,
dm_stripe_exit,
+ dm_io_exit,
dm_kcopyd_exit,
dm_interface_exit,
};
/*
* Block device functions
*/
+int dm_deleting_md(struct mapped_device *md)
+{
+ return test_bit(DMF_DELETING, &md->flags);
+}
+
static int dm_blk_open(struct block_device *bdev, fmode_t mode)
{
struct mapped_device *md;
goto out;
if (test_bit(DMF_FREEING, &md->flags) ||
- test_bit(DMF_DELETING, &md->flags)) {
+ dm_deleting_md(md)) {
md = NULL;
goto out;
}
unsigned int cmd, unsigned long arg)
{
struct mapped_device *md = bdev->bd_disk->private_data;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
struct dm_target *tgt;
int r = -ENOTTY;
tgt = dm_table_get_target(map, 0);
- if (dm_suspended(md)) {
+ if (dm_suspended_md(md)) {
r = -EAGAIN;
goto out;
}
mempool_free(tio, md->tio_pool);
}
-static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md)
+static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
+ gfp_t gfp_mask)
{
- return mempool_alloc(md->tio_pool, GFP_ATOMIC);
+ return mempool_alloc(md->tio_pool, gfp_mask);
}
static void free_rq_tio(struct dm_rq_target_io *tio)
mempool_free(info, info->tio->md->io_pool);
}
+static int md_in_flight(struct mapped_device *md)
+{
+ return atomic_read(&md->pending[READ]) +
+ atomic_read(&md->pending[WRITE]);
+}
+
static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
* function to access the md->map field, and make sure they call
* dm_table_put() when finished.
*/
-struct dm_table *dm_get_table(struct mapped_device *md)
+struct dm_table *dm_get_live_table(struct mapped_device *md)
{
struct dm_table *t;
unsigned long flags;
struct mapped_device *md = io->md;
/* Push-back supersedes any I/O errors */
- if (error && !(io->error > 0 && __noflush_suspending(md)))
- io->error = error;
+ if (unlikely(error)) {
+ spin_lock_irqsave(&io->endio_lock, flags);
+ if (!(io->error > 0 && __noflush_suspending(md)))
+ io->error = error;
+ spin_unlock_irqrestore(&io->endio_lock, flags);
+ }
if (atomic_dec_and_test(&io->io_count)) {
if (io->error == DM_ENDIO_REQUEUE) {
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.
* Or do dm_get() before calling this function and dm_put() later.
*/
-static void rq_completed(struct mapped_device *md, int run_queue)
+static void rq_completed(struct mapped_device *md, int rw, 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);
+ atomic_dec(&md->pending[rw]);
/* nudge anyone waiting on suspend queue */
- if (wakeup_waiters)
+ if (!md_in_flight(md))
wake_up(&md->wait);
if (run_queue)
- blk_run_queue(q);
+ blk_run_queue(md->queue);
/*
* dm_put() must be at the end of this function. See the comment above
free_rq_tio(tio);
}
+/*
+ * Complete the clone and the original request.
+ * Must be called without queue lock.
+ */
+static void dm_end_request(struct request *clone, int error)
+{
+ int rw = rq_data_dir(clone);
+ int run_queue = 1;
+ bool is_barrier = blk_barrier_rq(clone);
+ 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) && !is_barrier) {
+ 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;
+ }
+
+ 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);
+}
+
static void dm_unprep_request(struct request *rq)
{
struct request *clone = rq->special;
*/
void dm_requeue_unmapped_request(struct request *clone)
{
+ int rw = rq_data_dir(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;
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * 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);
blk_requeue_request(q, rq);
spin_unlock_irqrestore(q->queue_lock, flags);
- rq_completed(md, 0);
+ rq_completed(md, rw, 0);
}
EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request);
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)
+static void dm_done(struct request *clone, int error, bool mapped)
{
+ int r = error;
struct dm_rq_target_io *tio = clone->end_io_data;
- struct mapped_device *md = tio->md;
- struct request *rq = tio->orig;
+ dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io;
- if (blk_pc_request(rq)) {
- rq->errors = clone->errors;
- rq->resid_len = clone->resid_len;
+ if (mapped && rq_end_io)
+ r = rq_end_io(tio->ti, clone, error, &tio->info);
- 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;
+ if (r <= 0)
+ /* The target wants to complete the I/O */
+ dm_end_request(clone, r);
+ else if (r == DM_ENDIO_INCOMPLETE)
+ /* The target will handle the I/O */
+ return;
+ else if (r == DM_ENDIO_REQUEUE)
+ /* The target wants to requeue the I/O */
+ dm_requeue_unmapped_request(clone);
+ else {
+ DMWARN("unimplemented target endio return value: %d", r);
+ BUG();
}
-
- free_rq_clone(clone);
-
- blk_end_request_all(rq, error);
-
- rq_completed(md, 1);
}
/*
*/
static void dm_softirq_done(struct request *rq)
{
+ bool mapped = true;
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 (rq->cmd_flags & REQ_FAILED)
+ mapped = false;
- 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();
- }
+ dm_done(clone, tio->error, mapped);
}
/*
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * 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);
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * 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);
}
struct clone_info ci;
int error = 0;
- ci.map = dm_get_table(md);
+ ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
if (!bio_rw_flagged(bio, BIO_RW_BARRIER))
bio_io_error(bio);
atomic_set(&ci.io->io_count, 1);
ci.io->bio = bio;
ci.io->md = md;
+ spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
ci.sector_count = bio_sectors(bio);
if (unlikely(bio_empty_barrier(bio)))
struct bio_vec *biovec)
{
struct mapped_device *md = q->queuedata;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
sector_t max_sectors;
int max_size = 0;
{
struct mapped_device *md = q->queuedata;
- if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
-
return md->saved_make_request_fn(q, bio); /* call __make_request() */
}
return _dm_request(q, bio);
}
+/*
+ * Mark this request as flush request, so that dm_request_fn() can
+ * recognize.
+ */
+static void dm_rq_prepare_flush(struct request_queue *q, struct request *rq)
+{
+ rq->cmd_type = REQ_TYPE_LINUX_BLOCK;
+ rq->cmd[0] = REQ_LB_OP_FLUSH;
+}
+
+static bool dm_rq_is_flush_request(struct request *rq)
+{
+ if (rq->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+ rq->cmd[0] == REQ_LB_OP_FLUSH)
+ return true;
+ else
+ return false;
+}
+
void dm_dispatch_request(struct request *rq)
{
int r;
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);
+ int r;
- if (r)
- return 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;
+ }
- 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)
+static struct request *clone_rq(struct request *rq, struct mapped_device *md,
+ gfp_t gfp_mask)
{
- return !md->suspend_rq.special;
+ struct request *clone;
+ struct dm_rq_target_io *tio;
+
+ tio = alloc_rq_tio(md, gfp_mask);
+ if (!tio)
+ return NULL;
+
+ 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 NULL;
+ }
+
+ return clone;
}
/*
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(dm_rq_is_flush_request(rq)))
+ return BLKPREP_OK;
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 */
+ clone = clone_rq(rq, md, GFP_ATOMIC);
+ if (!clone)
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,
+static void map_request(struct dm_target *ti, struct request *clone,
struct mapped_device *md)
{
int r;
- struct request *clone = rq->special;
struct dm_rq_target_io *tio = clone->end_io_data;
/*
break;
case DM_MAPIO_REMAPPED:
/* The target has remapped the I/O so dispatch it */
+ trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
+ blk_rq_pos(tio->orig));
dm_dispatch_request(clone);
break;
case DM_MAPIO_REQUEUE:
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_table *map = dm_get_live_table(md);
struct dm_target *ti;
- struct request *rq;
+ struct request *rq, *clone;
/*
- * For noflush suspend, check blk_queue_stopped() to immediately
- * quit I/O dispatching.
+ * For suspend, check blk_queue_stopped() and increment
+ * ->pending within a single queue_lock not to increment the
+ * number of in-flight I/Os after the queue is stopped in
+ * dm_suspend().
*/
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);
+ if (unlikely(dm_rq_is_flush_request(rq))) {
+ BUG_ON(md->flush_request);
+ md->flush_request = rq;
blk_start_request(rq);
- __blk_end_request_all(rq, 0);
- wake_up(&md->wait);
+ queue_work(md->wq, &md->barrier_work);
goto out;
}
goto plug_and_out;
blk_start_request(rq);
+ clone = rq->special;
+ atomic_inc(&md->pending[rq_data_dir(clone)]);
+
spin_unlock(q->queue_lock);
- map_request(ti, rq, md);
+ map_request(ti, clone, md);
spin_lock_irq(q->queue_lock);
}
{
int r;
struct mapped_device *md = q->queuedata;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))
r = 1;
static void dm_unplug_all(struct request_queue *q)
{
struct mapped_device *md = q->queuedata;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
if (map) {
if (dm_request_based(md))
struct dm_table *map;
if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
if (map) {
/*
* Request-based dm cares about only own queue for
return r;
}
-static struct block_device_operations dm_blk_dops;
+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);
/*
* Allocate and initialise a blank device with a given minor.
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_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);
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);
+ blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH,
+ dm_rq_prepare_flush);
md->disk = alloc_disk(1);
if (!md->disk)
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;
bad_bdev:
destroy_workqueue(md->wq);
bad_thread:
+ del_gendisk(md->disk);
put_disk(md->disk);
bad_disk:
blk_cleanup_queue(md->queue);
mutex_unlock(&md->bdev->bd_inode->i_mutex);
}
-static int __bind(struct mapped_device *md, struct dm_table *t,
- struct queue_limits *limits)
+/*
+ * Returns old map, which caller must destroy.
+ */
+static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
+ struct queue_limits *limits)
{
+ struct dm_table *old_map;
struct request_queue *q = md->queue;
sector_t size;
unsigned long flags;
__set_size(md, size);
- if (!size) {
- dm_table_destroy(t);
- return 0;
- }
-
dm_table_event_callback(t, event_callback, md);
/*
__bind_mempools(md, t);
write_lock_irqsave(&md->map_lock, flags);
+ old_map = md->map;
md->map = t;
dm_table_set_restrictions(t, q, limits);
write_unlock_irqrestore(&md->map_lock, flags);
- return 0;
+ return old_map;
}
-static void __unbind(struct mapped_device *md)
+/*
+ * Returns unbound table for the caller to free.
+ */
+static struct dm_table *__unbind(struct mapped_device *md)
{
struct dm_table *map = md->map;
unsigned long flags;
if (!map)
- return;
+ return NULL;
dm_table_event_callback(map, NULL, NULL);
write_lock_irqsave(&md->map_lock, flags);
md->map = NULL;
write_unlock_irqrestore(&md->map_lock, flags);
- dm_table_destroy(map);
+
+ return map;
}
/*
BUG_ON(test_bit(DMF_FREEING, &md->flags));
if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
idr_replace(&_minor_idr, MINOR_ALLOCED,
MINOR(disk_devt(dm_disk(md))));
set_bit(DMF_FREEING, &md->flags);
spin_unlock(&_minor_lock);
- if (!dm_suspended(md)) {
+ if (!dm_suspended_md(md)) {
dm_table_presuspend_targets(map);
dm_table_postsuspend_targets(map);
}
dm_sysfs_exit(md);
dm_table_put(map);
- __unbind(md);
+ dm_table_destroy(__unbind(md));
free_dev(md);
}
}
{
int r = 0;
DECLARE_WAITQUEUE(wait, current);
- struct request_queue *q = md->queue;
- unsigned long flags;
dm_unplug_all(md->queue);
set_current_state(interruptible);
smp_mb();
- 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[0]) &&
- !atomic_read(&md->pending[1]))
+ if (!md_in_flight(md))
break;
if (interruptible == TASK_INTERRUPTIBLE &&
queue_work(md->wq, &md->work);
}
-/*
- * Swap in a new table (destroying old one).
- */
-int dm_swap_table(struct mapped_device *md, struct dm_table *table)
+static void dm_rq_set_flush_nr(struct request *clone, unsigned flush_nr)
{
- struct queue_limits limits;
- int r = -EINVAL;
+ struct dm_rq_target_io *tio = clone->end_io_data;
- mutex_lock(&md->suspend_lock);
+ tio->info.flush_request = flush_nr;
+}
- /* device must be suspended */
- if (!dm_suspended(md))
- goto out;
+/* 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;
- r = dm_calculate_queue_limits(table, &limits);
- if (r)
- goto out;
+ md->barrier_error = 0;
- /* cannot change the device type, once a table is bound */
- if (md->map &&
- (dm_table_get_type(md->map) != dm_table_get_type(table))) {
- DMWARN("can't change the device type after a table is bound");
- goto out;
+ 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_flush_nr(clone, j);
+ atomic_inc(&md->pending[rq_data_dir(clone)]);
+ map_request(ti, clone, md);
+ }
}
- __unbind(md);
- r = __bind(md, table, &limits);
-
-out:
- mutex_unlock(&md->suspend_lock);
- return r;
-}
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
+ dm_table_put(map);
-static void dm_rq_invalidate_suspend_marker(struct mapped_device *md)
-{
- md->suspend_rq.special = (void *)0x1;
+ return md->barrier_error;
}
-static void dm_rq_abort_suspend(struct mapped_device *md, int noflush)
+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;
- 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);
-}
+ /*
+ * 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);
-static void dm_rq_start_suspend(struct mapped_device *md, int noflush)
-{
- struct request *rq = &md->suspend_rq;
- struct request_queue *q = md->queue;
+ error = dm_rq_barrier(md);
- if (noflush)
- stop_queue(q);
- else {
- blk_rq_init(q, rq);
- blk_insert_request(q, rq, 0, NULL);
- }
+ 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);
}
-static int dm_rq_suspend_available(struct mapped_device *md, int noflush)
+/*
+ * Swap in a new table, returning the old one for the caller to destroy.
+ */
+struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
{
- int r = 1;
- struct request *rq = &md->suspend_rq;
- struct request_queue *q = md->queue;
- unsigned long flags;
+ struct dm_table *map = ERR_PTR(-EINVAL);
+ struct queue_limits limits;
+ int r;
- if (noflush)
- return r;
+ mutex_lock(&md->suspend_lock);
- /* 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;
+ /* device must be suspended */
+ if (!dm_suspended_md(md))
+ goto out;
+
+ r = dm_calculate_queue_limits(table, &limits);
+ if (r) {
+ map = ERR_PTR(r);
+ goto out;
}
- spin_unlock_irqrestore(q->queue_lock, flags);
- return r;
+ /* cannot change the device type, once a table is bound */
+ if (md->map &&
+ (dm_table_get_type(md->map) != dm_table_get_type(table))) {
+ DMWARN("can't change the device type after a table is bound");
+ goto out;
+ }
+
+ map = __bind(md, table, &limits);
+
+out:
+ mutex_unlock(&md->suspend_lock);
+ return map;
}
/*
/*
* 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)
- *
+ * 1. Flush all I/Os by lock_fs() if needed.
+ * 2. Stop dispatching any I/O by stopping the request_queue.
+ * 3. Wait for all in-flight I/Os to be completed or requeued.
*
- * 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.
+ * To abort suspend, start the request_queue.
*/
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
{
mutex_lock(&md->suspend_lock);
- if (dm_suspended(md)) {
+ if (dm_suspended_md(md)) {
r = -EINVAL;
goto out_unlock;
}
- if (dm_request_based(md) && !dm_rq_suspend_available(md, noflush)) {
- r = -EBUSY;
- goto out_unlock;
- }
-
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
/*
* DMF_NOFLUSH_SUSPENDING must be set before presuspend.
dm_table_presuspend_targets(map);
/*
- * Flush I/O to the device. noflush supersedes do_lockfs,
- * because lock_fs() needs to flush I/Os.
+ * Flush I/O to the device.
+ * Any I/O submitted after lock_fs() may not be flushed.
+ * noflush takes precedence over do_lockfs.
+ * (lock_fs() flushes I/Os and waits for them to complete.)
*/
if (!noflush && do_lockfs) {
r = lock_fs(md);
set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
- flush_workqueue(md->wq);
-
+ /*
+ * 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.
+ */
if (dm_request_based(md))
- dm_rq_start_suspend(md, noflush);
+ stop_queue(md->queue);
+
+ flush_workqueue(md->wq);
/*
* At this point no more requests are entering target request routines.
dm_queue_flush(md);
if (dm_request_based(md))
- dm_rq_abort_suspend(md, noflush);
+ start_queue(md->queue);
unlock_fs(md);
goto out; /* pushback list is already flushed, so skip flush */
* requests are being added to md->deferred list.
*/
- dm_table_postsuspend_targets(map);
-
set_bit(DMF_SUSPENDED, &md->flags);
+ dm_table_postsuspend_targets(map);
+
out:
dm_table_put(map);
struct dm_table *map = NULL;
mutex_lock(&md->suspend_lock);
- if (!dm_suspended(md))
+ if (!dm_suspended_md(md))
goto out;
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
if (!map || !dm_table_get_size(map))
goto out;
return NULL;
if (test_bit(DMF_FREEING, &md->flags) ||
- test_bit(DMF_DELETING, &md->flags))
+ dm_deleting_md(md))
return NULL;
dm_get(md);
return md;
}
-int dm_suspended(struct mapped_device *md)
+int dm_suspended_md(struct mapped_device *md)
{
return test_bit(DMF_SUSPENDED, &md->flags);
}
+int dm_suspended(struct dm_target *ti)
+{
+ struct mapped_device *md = dm_table_get_md(ti->table);
+ int r = dm_suspended_md(md);
+
+ dm_put(md);
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(dm_suspended);
+
int dm_noflush_suspending(struct dm_target *ti)
{
struct mapped_device *md = dm_table_get_md(ti->table);
kfree(pools);
}
-static struct block_device_operations dm_blk_dops = {
+static const struct block_device_operations dm_blk_dops = {
.open = dm_blk_open,
.release = dm_blk_close,
.ioctl = dm_blk_ioctl,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff