md: check level before create and exit io_acct_set

The bio_set (io_acct_set) is used by personalities to clone bio and
trace the timestamp of bio. Some personalities such as raid1/10 don't
need the bio_set, so add check to not create it unconditionally.

Also update the comment for md_account_bio to make it more clear.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 32abcfb8bcadb735342fdb1336ab64a1b605e9dd..56b606184c87f2f4830c560421fe4021f271f805 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2341,7 +2341,8 @@ int md_integrity_register(struct mddev *mddev)
 
        pr_debug("md: data integrity enabled on %s\n", mdname(mddev));
        if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE) ||
-           bioset_integrity_create(&mddev->io_acct_set, BIO_POOL_SIZE)) {
+           (mddev->level != 1 && mddev->level != 10 &&
+            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;
@@ -5570,7 +5571,8 @@ static void md_free(struct kobject *ko)
 
        bioset_exit(&mddev->bio_set);
        bioset_exit(&mddev->sync_set);
-       bioset_exit(&mddev->io_acct_set);
+       if (mddev->level != 1 && mddev->level != 10)
+               bioset_exit(&mddev->io_acct_set);
        kfree(mddev);
 }
 
@@ -5866,7 +5868,8 @@ int md_run(struct mddev *mddev)
                if (err)
                        goto exit_bio_set;
        }
-       if (!bioset_initialized(&mddev->io_acct_set)) {
+       if (mddev->level != 1 && mddev->level != 10 &&
+           !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)
@@ -6048,7 +6051,8 @@ bitmap_abort:
        module_put(pers->owner);
        md_bitmap_destroy(mddev);
 abort:
-       bioset_exit(&mddev->io_acct_set);
+       if (mddev->level != 1 && mddev->level != 10)
+               bioset_exit(&mddev->io_acct_set);
 exit_sync_set:
        bioset_exit(&mddev->sync_set);
 exit_bio_set:
@@ -6276,7 +6280,8 @@ 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);
+       if (mddev->level != 1 && mddev->level != 10)
+               bioset_exit(&mddev->io_acct_set);
 }
 
 EXPORT_SYMBOL_GPL(md_stop);
@@ -8593,7 +8598,10 @@ static void md_end_io_acct(struct bio *bio)
        bio_endio(orig_bio);
 }
 
-/* used by personalities (raid0 and raid5) to account io stats */
+/*
+ * Used by personalities that don't already clone the bio and thus can't
+ * easily add the timestamp to their extended bio structure.
+ */
 void md_account_bio(struct mddev *mddev, struct bio **bio)
 {
        struct md_io_acct *md_io_acct;