Rediffed for RHEL7.4.z.
Conflicts:
The return value of md_make_request is different from RHEL to upstream.
And RHEL7 MD code does not use bio->bi_opf, but bio->bi_rw.
-Nigel Croxon
commit 393debc23c7820211d1c8253dd6a8408a7628fe7
Author: Shaohua Li <shli@xxxxxx>
Date: Thu Sep 21 10:23:35 2017 -0700
md: separate request handling
With commit cc27b0c78c79, pers->make_request could bail out without handling
the bio. If that happens, we should retry. The commit fixes md_make_request
but not other call sites. Separate the request handling part, so other call
sites can use it.
Reported-by: Nate Dailey <nate.dailey@xxxxxxxxxxx>
Fix: cc27b0c78c79(md: fix deadlock between mddev_suspend() and md_write_start())
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
Signed-off-by: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 85fe7a99290..407e15f4bfe 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -248,21 +248,8 @@ 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.
*/
-static void md_make_request(struct request_queue *q, struct bio *bio)
+void md_handle_request(struct mddev *mddev, struct bio *bio)
{
- const int rw = bio_data_dir(bio);
- struct mddev *mddev = q->queuedata;
- int cpu;
- unsigned int sectors;
-
- if (mddev == NULL || mddev->pers == NULL) {
- bio_io_error(bio);
- return;
- }
- if (mddev->ro == 1 && unlikely(rw == WRITE)) {
- bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
- return;
- }
check_suspended:
smp_rmb(); /* Ensure implications of 'active' are visible */
rcu_read_lock();
@@ -282,24 +269,45 @@ check_suspended:
atomic_inc(&mddev->active_io);
rcu_read_unlock();
- /*
- * save the sectors now since our bio can
- * go away inside make_request
- */
- sectors = bio_sectors(bio);
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 void md_make_request(struct request_queue *q, struct bio *bio)
+{
+ const int rw = bio_data_dir(bio);
+ struct mddev *mddev = q->queuedata;
+ int cpu;
+ unsigned int sectors;
+
+ if (mddev == NULL || mddev->pers == NULL) {
+ bio_io_error(bio);
+ return;
+ }
+ if (mddev->ro == 1 && unlikely(rw == WRITE)) {
+ bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
+ return;
+ }
+
+ /*
+ * save the sectors now since our bio can
+ * go away inside make_request
+ */
+ sectors = bio_sectors(bio);
+
+ 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);
}
/* mddev_suspend makes sure no new requests are submitted
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 0d13bf88f41..12e19d6d373 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -679,6 +679,7 @@ extern void md_stop_writes(struct mddev *mddev);
extern int md_rdev_init(struct md_rdev *rdev);
extern void md_rdev_clear(struct md_rdev *rdev);
+extern void md_handle_request(struct mddev *mddev, struct bio *bio);
extern void mddev_suspend(struct mddev *mddev);
extern void mddev_resume(struct mddev *mddev);
extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
--
2.16.2