在 2023/12/22 2:58, Song Liu 写道:
Hi,
On Wed, Dec 20, 2023 at 11:13 PM <linan666@xxxxxxxxxxxxxxx> wrote:
From: Li Nan <linan122@xxxxxxxxxx>
Removing a device can trigger WARN_ON in bd_unlink_disk_holder() if creating
symlink failed while adding device.
WARNING: CPU: 0 PID: 742 at block/holder.c:145 bd_unlink_disk_holder+0x17b/0x1a0
Fix it by adding the flag 'SymlinkCreated', which only be set after
creating symlink success.
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
drivers/md/md.h | 3 +++
drivers/md/md.c | 8 ++++++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 8d881cc59799..427d17713a8c 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -207,6 +207,9 @@ enum flag_bits {
* check if there is collision between raid1
* serial bios.
*/
+ SymlinkCreated, /* This device has created the symlink
+ * with gendisk.
+ */
In general, I would like to avoid adding flags if possible.
This flag is mainly used to fix deadlock in next patch. Or should we
export bd_find_holder_disk()? Link hodler if it return NULL.
just like:
rdev_for_each_rcu
if (!bd_find_holder_disk)
bd_link_disk_holder
};
static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
diff --git a/drivers/md/md.c b/drivers/md/md.c
index e05858653a41..d6612b922c76 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2526,7 +2526,8 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
sysfs_get_dirent_safe(rdev->kobj.sd, "bad_blocks");
list_add_rcu(&rdev->same_set, &mddev->disks);
- bd_link_disk_holder(rdev->bdev, mddev->gendisk);
+ if (!bd_link_disk_holder(rdev->bdev, mddev->gendisk))
+ set_bit(SymlinkCreated, &rdev->flags);
Shall we just fail bind_rdev_to_array() if bd_link_disk_holder()
returns non-zero?
I keep this action because of commit 00bcb4ac7ee7 ("md: reduce
dependence on sysfs."). Fail bind_rdev_to_array is good to me.
Thanks,
Song
.
--
Thanks,
Nan
