[PATCH -next 01/29] md: use READ_ONCE/WRITE_ONCE for 'suspend_lo' and 'suspend_hi'
From: Yu Kuai <hidden>
Date: 2023-08-03 13:34:28
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
From: Yu Kuai <redacted> Because reading 'suspend_lo' and 'suspend_hi' from md_handle_request() is not protected, use READ_ONCE/WRITE_ONCE to prevent reading abnormal value. Signed-off-by: Yu Kuai <redacted> --- drivers/md/md.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 55a74d9b7457..5aa9f62a7c56 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c@@ -358,11 +358,11 @@ static bool is_suspended(struct mddev *mddev, struct bio *bio) return true; if (bio_data_dir(bio) != WRITE) return false; - if (mddev->suspend_lo >= mddev->suspend_hi) + if (READ_ONCE(mddev->suspend_lo) >= READ_ONCE(mddev->suspend_hi)) return false; - if (bio->bi_iter.bi_sector >= mddev->suspend_hi) + if (bio->bi_iter.bi_sector >= READ_ONCE(mddev->suspend_hi)) return false; - if (bio_end_sector(bio) < mddev->suspend_lo) + if (bio_end_sector(bio) < READ_ONCE(mddev->suspend_lo)) return false; return true; }
@@ -5174,7 +5174,8 @@ __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store); static ssize_t suspend_lo_show(struct mddev *mddev, char *page) { - return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo); + return sprintf(page, "%llu\n", + (unsigned long long)READ_ONCE(mddev->suspend_lo)); } static ssize_t
@@ -5194,7 +5195,7 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len) return err; mddev_suspend(mddev); - mddev->suspend_lo = new; + WRITE_ONCE(mddev->suspend_lo, new); mddev_resume(mddev); mddev_unlock(mddev);
@@ -5206,7 +5207,8 @@ __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store); static ssize_t suspend_hi_show(struct mddev *mddev, char *page) { - return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi); + return sprintf(page, "%llu\n", + (unsigned long long)READ_ONCE(mddev->suspend_hi)); } static ssize_t
@@ -5226,7 +5228,7 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len) return err; mddev_suspend(mddev); - mddev->suspend_hi = new; + WRITE_ONCE(mddev->suspend_hi, new); mddev_resume(mddev); mddev_unlock(mddev);
--
2.39.2