md: Revert "md: Fix overflow in is_mddev_idle"

This reverts commit 3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e.

Using 64bit for 'sync_io' is unnecessary from the gendisk side. This
overflow will not cause any functional impact, except for a UBSAN
warning. Solving this overflow requires introducing additional
calculations and checks which are not necessary. So just keep using
32bit for 'sync_io'.

Signed-off-by: Li Nan <linan122@huawei.com>
Link: https://lore.kernel.org/r/20240507023103.781816-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 00bbafcd27bbddd18b64434217a759370cdbb23f..aff9118ff69750f294c07bbbb3a9168cb4ba43ae 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8577,7 +8577,7 @@ static int is_mddev_idle(struct mddev *mddev, int init)
 {
        struct md_rdev *rdev;
        int idle;
-       long long curr_events;
+       int curr_events;
 
        idle = 1;
        rcu_read_lock();
@@ -8587,9 +8587,8 @@ static int is_mddev_idle(struct mddev *mddev, int init)
                if (!init && !blk_queue_io_stat(disk->queue))
                        continue;
 
-               curr_events =
-                       (long long)part_stat_read_accum(disk->part0, sectors) -
-                       atomic64_read(&disk->sync_io);
+               curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
+                             atomic_read(&disk->sync_io);
                /* sync IO will cause sync_io to increase before the disk_stats
                 * as sync_io is counted when a request starts, and
                 * disk_stats is counted when it completes.

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 029dd0491a36612bfa38159972e14312cccfbc8a..ca085ecad50449df0d6dca762e6c11e09839c553 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -51,7 +51,7 @@ struct md_rdev {
 
        sector_t sectors;               /* Device size (in 512bytes sectors) */
        struct mddev *mddev;            /* RAID array if running */
-       long long last_events;          /* IO event timestamp */
+       int last_events;                /* IO event timestamp */
 
        /*
         * If meta_bdev is non-NULL, it means that a separate device is
@@ -622,7 +622,7 @@ extern void mddev_unlock(struct mddev *mddev);
 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
 {
        if (blk_queue_io_stat(bdev->bd_disk->queue))
-               atomic64_add(nr_sectors, &bdev->bd_disk->sync_io);
+               atomic_add(nr_sectors, &bdev->bd_disk->sync_io);
 }
 
 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3b18a40a1fc109dbbf94c20385fbd53fdde85c1f..26acf80c50c03de65ff800e12664cf828d9e203b 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -172,7 +172,7 @@ struct gendisk {
        struct list_head slave_bdevs;
 #endif
        struct timer_rand_state *random;
-       atomic64_t sync_io;             /* RAID */
+       atomic_t sync_io;               /* RAID */
        struct disk_events *ev;
 
 #ifdef CONFIG_BLK_DEV_ZONED