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path: root/drivers/md/md.c
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Diffstat (limited to 'drivers/md/md.c')
-rw-r--r--drivers/md/md.c72
1 files changed, 43 insertions, 29 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 08fcaebc61bd..0ff1bbf6c90e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -266,6 +266,37 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
* call has finished, the bio has been linked into some internal structure
* and so is visible to ->quiesce(), so we don't need the refcount any more.
*/
+void md_handle_request(struct mddev *mddev, struct bio *bio)
+{
+check_suspended:
+ rcu_read_lock();
+ if (mddev->suspended) {
+ DEFINE_WAIT(__wait);
+ for (;;) {
+ prepare_to_wait(&mddev->sb_wait, &__wait,
+ TASK_UNINTERRUPTIBLE);
+ if (!mddev->suspended)
+ break;
+ rcu_read_unlock();
+ schedule();
+ rcu_read_lock();
+ }
+ finish_wait(&mddev->sb_wait, &__wait);
+ }
+ atomic_inc(&mddev->active_io);
+ rcu_read_unlock();
+
+ if (!mddev->pers->make_request(mddev, bio)) {
+ atomic_dec(&mddev->active_io);
+ wake_up(&mddev->sb_wait);
+ goto check_suspended;
+ }
+
+ if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
+ wake_up(&mddev->sb_wait);
+}
+EXPORT_SYMBOL(md_handle_request);
+
static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
{
const int rw = bio_data_dir(bio);
@@ -285,23 +316,6 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
bio_endio(bio);
return BLK_QC_T_NONE;
}
-check_suspended:
- rcu_read_lock();
- if (mddev->suspended) {
- DEFINE_WAIT(__wait);
- for (;;) {
- prepare_to_wait(&mddev->sb_wait, &__wait,
- TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended)
- break;
- rcu_read_unlock();
- schedule();
- rcu_read_lock();
- }
- finish_wait(&mddev->sb_wait, &__wait);
- }
- atomic_inc(&mddev->active_io);
- rcu_read_unlock();
/*
* save the sectors now since our bio can
@@ -310,20 +324,14 @@ check_suspended:
sectors = bio_sectors(bio);
/* bio could be mergeable after passing to underlayer */
bio->bi_opf &= ~REQ_NOMERGE;
- if (!mddev->pers->make_request(mddev, bio)) {
- atomic_dec(&mddev->active_io);
- wake_up(&mddev->sb_wait);
- goto check_suspended;
- }
+
+ md_handle_request(mddev, bio);
cpu = part_stat_lock();
part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
part_stat_unlock();
- if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
- wake_up(&mddev->sb_wait);
-
return BLK_QC_T_NONE;
}
@@ -439,16 +447,22 @@ static void md_submit_flush_data(struct work_struct *ws)
struct mddev *mddev = container_of(ws, struct mddev, flush_work);
struct bio *bio = mddev->flush_bio;
+ /*
+ * must reset flush_bio before calling into md_handle_request to avoid a
+ * deadlock, because other bios passed md_handle_request suspend check
+ * could wait for this and below md_handle_request could wait for those
+ * bios because of suspend check
+ */
+ mddev->flush_bio = NULL;
+ wake_up(&mddev->sb_wait);
+
if (bio->bi_iter.bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio);
else {
bio->bi_opf &= ~REQ_PREFLUSH;
- mddev->pers->make_request(mddev, bio);
+ md_handle_request(mddev, bio);
}
-
- mddev->flush_bio = NULL;
- wake_up(&mddev->sb_wait);
}
void md_flush_request(struct mddev *mddev, struct bio *bio)