Thanks, applied. I reworded the commit description a bit, putting the
explanation first, and cleaning up the text a bit to make it more
readable:
commit 558d6450c7755aa005d89021204b6cdcae5e848f
Author: Ye Bin <yebin10@xxxxxxxxxx>
Date: Tue Jun 15 17:05:37 2021 +0800
ext4: fix WARN_ON_ONCE(!buffer_uptodate) after an error writing the superblock
If a writeback of the superblock fails with an I/O error, the buffer
is marked not uptodate. However, this can cause a WARN_ON to trigger
when we attempt to write superblock a second time. (Which might
succeed this time, for cerrtain types of block devices such as iSCSI
devices over a flaky network.)
Try to detect this case in flush_stashed_error_work(), and also change
__ext4_handle_dirty_metadata() so we always set the uptodate flag, not
just in the nojournal case.
Before this commit, this problem can be repliciated via:
1. dmsetup create dust1 --table '0 2097152 dust /dev/sdc 0 4096'
2. mount /dev/mapper/dust1 /home/test
3. dmsetup message dust1 0 addbadblock 0 10
4. cd /home/test
5. echo "XXXXXXX" > t
After a few seconds, we got following warning:
... <rest of commit description was unchanged, and omitted here>
