It has added io_acct_set for raid0/raid5 io accounting and it needs to
alloc md_io_acct in the i/o path. They are free when the bios come back
from member disks. Now we don't have a method to monitor if those bios
are all come back. In the takeover process, it needs to free the raid0
memory resource including the memory pool for md_io_acct. But maybe some
bios are still not returned. When those bios are returned, it can cause
panic bcause of introducing NULL pointer or invalid address.
This patch adds io_acct_cnt. So when stopping raid0, it can use this
to wait until all bios come back.
Reported-by: Fine Fan <ffan@xxxxxxxxxx>
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
---
drivers/md/md.c | 13 ++++++++++++-
drivers/md/md.h | 11 ++++++++---
drivers/md/raid0.c | 6 ++++++
3 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9dc0175280b4..57dc2ddf1e11 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -673,6 +673,7 @@ void mddev_init(struct mddev *mddev)
atomic_set(&mddev->flush_pending, 0);
init_waitqueue_head(&mddev->sb_wait);
init_waitqueue_head(&mddev->recovery_wait);
+ init_waitqueue_head(&mddev->wait_io_acct);
mddev->reshape_position = MaxSector;
mddev->reshape_backwards = 0;
mddev->last_sync_action = "none";
@@ -8600,15 +8601,18 @@ int acct_bioset_init(struct mddev *mddev)
{
int err = 0;
- if (!bioset_initialized(&mddev->io_acct_set))
+ if (!bioset_initialized(&mddev->io_acct_set)) {
+ atomic_set(&mddev->io_acct_cnt, 0);
err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE,
offsetof(struct md_io_acct, bio_clone), 0);
+ }
return err;
}
EXPORT_SYMBOL_GPL(acct_bioset_init);
void acct_bioset_exit(struct mddev *mddev)
{
+ WARN_ON(atomic_read(&mddev->io_acct_cnt) != 0);
bioset_exit(&mddev->io_acct_set);
}
EXPORT_SYMBOL_GPL(acct_bioset_exit);
@@ -8617,12 +8621,17 @@ static void md_end_io_acct(struct bio *bio)
{
struct md_io_acct *md_io_acct = bio->bi_private;
struct bio *orig_bio = md_io_acct->orig_bio;
+ struct mddev *mddev = md_io_acct->mddev;
orig_bio->bi_status = bio->bi_status;
bio_end_io_acct(orig_bio, md_io_acct->start_time);
bio_put(bio);
bio_endio(orig_bio);
+
+ if (atomic_dec_and_test(&mddev->io_acct_cnt))
+ if (unlikely(test_bit(MD_QUIESCE, &mddev->flags)))
+ wake_up(&mddev->wait_io_acct);
}
/*
@@ -8642,6 +8651,8 @@ void md_account_bio(struct mddev *mddev, struct bio **bio)
md_io_acct = container_of(clone, struct md_io_acct, bio_clone);
md_io_acct->orig_bio = *bio;
md_io_acct->start_time = bio_start_io_acct(*bio);
+ md_io_acct->mddev = mddev;
+ atomic_inc(&mddev->io_acct_cnt);
clone->bi_end_io = md_end_io_acct;
clone->bi_private = md_io_acct;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b4e2d8b87b61..061176ff325f 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -255,6 +255,7 @@ struct md_cluster_info;
* array is ready yet.
* @MD_BROKEN: This is used to stop writes and mark array as failed.
* @MD_DELETED: This device is being deleted
+ * @MD_QUIESCE: This device is being quiesced. Now only raid0 use this flag
*
* change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added
*/
@@ -272,6 +273,7 @@ enum mddev_flags {
MD_NOT_READY,
MD_BROKEN,
MD_DELETED,
+ MD_QUIESCE,
};
enum mddev_sb_flags {
@@ -513,6 +515,8 @@ struct mddev {
* metadata and bitmap writes
*/
struct bio_set io_acct_set; /* for raid0 and raid5 io accounting */
+ atomic_t io_acct_cnt;
+ wait_queue_head_t wait_io_acct;
/* Generic flush handling.
* The last to finish preflush schedules a worker to submit
@@ -710,9 +714,10 @@ struct md_thread {
};
struct md_io_acct {
- struct bio *orig_bio;
- unsigned long start_time;
- struct bio bio_clone;
+ struct bio *orig_bio;
+ unsigned long start_time;
+ struct bio bio_clone;
+ struct mddev *mddev;
};
#define THREAD_WAKEUP 0
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 857c49399c28..aced0ad8cdab 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -754,6 +754,12 @@ static void *raid0_takeover(struct mddev *mddev)
static void raid0_quiesce(struct mddev *mddev, int quiesce)
{
+ /* It doesn't use a separate struct to count how many bios are submitted
+ * to member disks to avoid memory alloc and performance decrease
+ */
+ set_bit(MD_QUIESCE, &mddev->flags);
+ wait_event(mddev->wait_io_acct, !atomic_read(&mddev->io_acct_cnt));
+ clear_bit(MD_QUIESCE, &mddev->flags);
}
static struct md_personality raid0_personality=
--
2.32.0 (Apple Git-132)
