New subject: [PATCH openEuler-5.10-LTS 02/20] md/raid5: avoid redundant bio clone in raid5_read_one_chunk

2 Aug 2022

From: Guoqing Jiang jgq516@gmail.com
mainline inclusion
from mainline-v5.14-rc1
commit 10764815ff4728d2c57da677cd5d3dd6f446cf5f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I587H6
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
-------------------------------
We introduce a new bioset (io_acct_set) for raid0 and raid5 since they
don't own clone infrastructure to accounting io. And the bioset is added
to mddev instead of to raid0 and raid5 layer, because with this way, we
can put common functions to md.h and reuse them in raid0 and raid5.
Also struct md_io_acct is added accordingly which includes io start_time,
the origin bio and cloned bio. Then we can call bio_{start,end}_io_acct
to get related io status.
Signed-off-by: Guoqing Jiang jiangguoqing@kylinos.cn
Signed-off-by: Song Liu song@kernel.org
Conflict:
    drivers/md/md.c
    drivers/md/md.h
Signed-off-by: Zhang Wensheng zhangwensheng5@huawei.com
Reviewed-by: Jason Yan yanaijie@huawei.com
Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com
---
 drivers/md/md.c    | 52 ++++++++++++++++++++++++++++++++++++++++++----
 drivers/md/md.h    |  8 +++++++
 drivers/md/raid0.c |  3 +++
 drivers/md/raid5.c |  9 ++++++++
 4 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index a299fda5b0e9..10d9a8bed604 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2361,7 +2361,8 @@ int md_integrity_register(struct mddev *mddev)
    		       bdev_get_integrity(reference->bdev));
pr_debug("md: data integrity enabled on %s\n", mdname(mddev));
-	if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE)) {
+	if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE) ||
+	    bioset_integrity_create(&mddev->io_acct_set, BIO_POOL_SIZE)) {
    	pr_err("md: failed to create integrity pool for %s\n",
    	       mdname(mddev));
    	return -EINVAL;
@@ -5597,6 +5598,7 @@ static void md_free(struct kobject *ko)
bioset_exit(&mddev->bio_set);
    bioset_exit(&mddev->sync_set);
+	bioset_exit(&mddev->io_acct_set);
    kfree(mddev);
 }
@@ -5885,7 +5887,13 @@ int md_run(struct mddev *mddev)
    if (!bioset_initialized(&mddev->sync_set)) {
    	err = bioset_init(&mddev->sync_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
    	if (err)
-			return err;
+			goto exit_bio_set;
+	}
+	if (!bioset_initialized(&mddev->io_acct_set)) {
+		err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE,
+				  offsetof(struct md_io_acct, bio_clone), 0);
+		if (err)
+			goto exit_sync_set;
    }
spin_lock(&pers_lock);
@@ -6013,6 +6021,7 @@ int md_run(struct mddev *mddev)
    		blk_queue_flag_set(QUEUE_FLAG_NONROT, mddev->queue);
    	else
    		blk_queue_flag_clear(QUEUE_FLAG_NONROT, mddev->queue);
+		blk_queue_flag_set(QUEUE_FLAG_IO_STAT, mddev->queue);
    }
    if (pers->sync_request) {
    	if (mddev->kobj.sd &&
@@ -6062,8 +6071,11 @@ int md_run(struct mddev *mddev)
    module_put(pers->owner);
    md_bitmap_destroy(mddev);
 abort:
-	bioset_exit(&mddev->bio_set);
+	bioset_exit(&mddev->io_acct_set);
+exit_sync_set:
    bioset_exit(&mddev->sync_set);
+exit_bio_set:
+	bioset_exit(&mddev->bio_set);
    return err;
 }
 EXPORT_SYMBOL_GPL(md_run);
@@ -6288,6 +6300,7 @@ void md_stop(struct mddev *mddev)
    __md_stop(mddev);
    bioset_exit(&mddev->bio_set);
    bioset_exit(&mddev->sync_set);
+	bioset_exit(&mddev->io_acct_set);
 }
EXPORT_SYMBOL_GPL(md_stop);
@@ -8571,9 +8584,40 @@ void md_write_end(struct mddev *mddev)
    		  roundup(jiffies, mddev->safemode_delay) +
    		  mddev->safemode_delay);
 }
-
 EXPORT_SYMBOL(md_write_end);
+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;
+
+	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);
+}
+
+/* used by personalities (raid0 and raid5) to account io stats */
+void md_account_bio(struct mddev *mddev, struct bio **bio)
+{
+	struct md_io_acct *md_io_acct;
+	struct bio *clone;
+
+	if (!blk_queue_io_stat((*bio)->bi_disk->queue))
+		return;
+
+	clone = bio_clone_fast(*bio, GFP_NOIO, &mddev->io_acct_set);
+	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);
+
+	clone->bi_end_io = md_end_io_acct;
+	clone->bi_private = md_io_acct;
+	*bio = clone;
+}
+EXPORT_SYMBOL_GPL(md_account_bio);
+
 /* md_allow_write(mddev)
  * Calling this ensures that the array is marked 'active' so that writes
  * may proceed without blocking.  It is important to call this before
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 85177d068322..20c16cfdd6bb 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -491,6 +491,7 @@ struct mddev {
    struct bio_set			sync_set; /* for sync operations like
    					   * metadata and bitmap writes
    					   */
+	struct bio_set			io_acct_set; /* for raid0 and raid5 io accounting */
/* Generic flush handling.
     * The last to finish preflush schedules a worker to submit
@@ -687,6 +688,12 @@ struct md_thread {
    void			*private;
 };
+struct md_io_acct {
+	struct bio *orig_bio;
+	unsigned long start_time;
+	struct bio bio_clone;
+};
+
 #define THREAD_WAKEUP  0
static inline void safe_put_page(struct page *p)
@@ -716,6 +723,7 @@ extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
 extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
 extern void md_finish_reshape(struct mddev *mddev);
+void md_account_bio(struct mddev *mddev, struct bio **bio);
extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 35843df15b5e..0312b192106a 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -556,6 +556,9 @@ static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
    	bio = split;
    }
+	if (bio->bi_pool != &mddev->bio_set)
+		md_account_bio(mddev, &bio);
+
    orig_sector = sector;
    zone = find_zone(mddev->private, &sector);
    switch (conf->layout) {
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c82953a3299e..35dacc6e754f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5487,6 +5487,7 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
    sector_t sector = raid_bio->bi_iter.bi_sector;
    unsigned chunk_sects = mddev->chunk_sectors;
    unsigned sectors = chunk_sects - (sector & (chunk_sects-1));
+	struct r5conf *conf = mddev->private;
if (sectors < bio_sectors(raid_bio)) {
    	struct r5conf *conf = mddev->private;
@@ -5496,6 +5497,9 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
    	raid_bio = split;
    }
+	if (raid_bio->bi_pool != &conf->bio_split)
+		md_account_bio(mddev, &raid_bio);
+
    if (!raid5_read_one_chunk(mddev, raid_bio))
    	return raid_bio;
@@ -5775,6 +5779,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
    DEFINE_WAIT(w);
    bool do_prepare;
    bool do_flush = false;
+	bool do_clone = false;
if (unlikely(bi->bi_opf & REQ_PREFLUSH)) {
    	int ret = log_handle_flush_request(conf, bi);
@@ -5803,6 +5808,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
    if (rw == READ && mddev->degraded == 0 &&
        mddev->reshape_position == MaxSector) {
    	bi = chunk_aligned_read(mddev, bi);
+		do_clone = true;
    	if (!bi)
    		return true;
    }
@@ -5817,6 +5823,9 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
    last_sector = bio_end_sector(bi);
    bi->bi_next = NULL;
+	if (!do_clone)
+		md_account_bio(mddev, &bi);
+
    prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
    for (; logical_sector < last_sector; logical_sector += RAID5_STRIPE_SECTORS(conf)) {
    	int previous;
-- 
2.20.1

    

[PATCH openEuler-5.10-LTS 01/20] md: add io accounting for raid0 and raid5