*/
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)
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)
/*
/* 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;
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;
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)
{
* 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;
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);
}
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);
}
}
{
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 (!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 &&
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.
* 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;
goto out_unlock;
}
+ if (dm_request_based(md) && !dm_rq_suspend_available(md, noflush)) {
+ r = -EBUSY;
+ goto out_unlock;
+ }
+
map = dm_get_table(md);
/*
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
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 */
}
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);
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff