On 2023/11/7 19:12, Yu Kuai wrote:
From: Yu Kuai <yukuai3@xxxxxxxxxx>
If one of the underlying disks of raid or dm is set to read-only, then
each io will generate new log, which will cause message storm. This
environment is indeed problematic, however we can't make sure our
naive custormer won't do this, hence use pr_warn_ratelimited() to
prevent message storm in this case.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
block/blk-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 9d51e9894ece..fdf25b8d6e78 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -501,8 +501,8 @@ static inline void bio_check_ro(struct bio *bio)
if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) {
if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
return;
- pr_warn("Trying to write to read-only block-device %pg\n",
- bio->bi_bdev);
+ pr_warn_ratelimited("Trying to write to read-only block-device %pg\n",
+ bio->bi_bdev);
Acctually, before commit 57e95e4670d1 ("block: fix and cleanup
bio_check_ro") , there's only print warning once.
I wrote a patch earlier, set GD_ROWR_WARNED flag for disk after emit
warning. You can look at the patch in the
attachment, Is it possible to solve your problem.
/* Older lvm-tools actually trigger this */
}
}
>From 82b7dd41eb447e9fdd3d7c5d5e3a002a9f284d82 Mon Sep 17 00:00:00 2001
From: Ye Bin <yebin10@xxxxxxxxxx>
Date: Wed, 9 Aug 2023 16:11:39 +0800
Subject: [PATCH] block: only print warning once when write to readonly bdev
After commit 57e95e4670d1 there will print warning unconditionally.As a result,
alarm logs are flooded.
To solve above issue, introduce GD_ROWR_WARNED state for every partition to
record if warning has been printed.
Fixes: 57e95e4670d1 ("block: fix and cleanup bio_check_ro")
Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
---
block/blk-core.c | 3 +++
block/genhd.c | 1 +
block/ioctl.c | 6 +++++-
include/linux/blkdev.h | 1 +
4 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 9d51e9894ece..69d9757a013a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -501,6 +501,9 @@ static inline void bio_check_ro(struct bio *bio)
if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) {
if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
return;
+ if (test_and_set_bit(GD_ROWR_WARNED,
+ &bio->bi_bdev->bd_disk->state))
+ return;
pr_warn("Trying to write to read-only block-device %pg\n",
bio->bi_bdev);
/* Older lvm-tools actually trigger this */
diff --git a/block/genhd.c b/block/genhd.c
index c9d06f72c587..c05d2cd4a87b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1455,6 +1455,7 @@ void set_disk_ro(struct gendisk *disk, bool read_only)
if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
return;
}
+ clear_bit(GD_ROWR_WARNED, &disk->state);
set_disk_ro_uevent(disk, read_only);
}
EXPORT_SYMBOL(set_disk_ro);
diff --git a/block/ioctl.c b/block/ioctl.c
index 4160f4e6bd5b..a2158c5e8e3e 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -394,7 +394,11 @@ static int blkdev_roset(struct block_device *bdev, unsigned cmd,
if (ret)
return ret;
}
- bdev->bd_read_only = n;
+ if (!bdev->bd_read_only != !n) {
+ bdev->bd_read_only = n;
+ clear_bit(GD_ROWR_WARNED, &bdev->bd_disk->state);
+ }
+
return 0;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 51fa7ffdee83..832f7f81e46c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -157,6 +157,7 @@ struct gendisk {
#define GD_ADDED 4
#define GD_SUPPRESS_PART_SCAN 5
#define GD_OWNS_QUEUE 6
+#define GD_ROWR_WARNED 7
struct mutex open_mutex; /* open/close mutex */
unsigned open_partitions; /* number of open partitions */
--
2.31.1
