diff options
author | Ye Bin <yebin10@huawei.com> | 2021-06-15 17:05:37 +0800 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2021-07-01 10:58:04 -0400 |
commit | 558d6450c7755aa005d89021204b6cdcae5e848f (patch) | |
tree | fae68b29b1e6d56a6ed17df8f9ec255c1280ef5f /fs/ext4/super.c | |
parent | 8813587a996e7d2ae160be3b79f9f70d9fef4583 (diff) | |
download | linux-558d6450c7755aa005d89021204b6cdcae5e848f.tar.bz2 |
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:
[ 80.654487] end_buffer_async_write: bh=0xffff88842f18bdd0
[ 80.656134] Buffer I/O error on dev dm-0, logical block 0, lost async page write
[ 85.774450] EXT4-fs error (device dm-0): ext4_check_bdev_write_error:193: comm kworker/u16:8: Error while async write back metadata
[ 91.415513] mark_buffer_dirty: bh=0xffff88842f18bdd0
[ 91.417038] ------------[ cut here ]------------
[ 91.418450] WARNING: CPU: 1 PID: 1944 at fs/buffer.c:1092 mark_buffer_dirty.cold+0x1c/0x5e
[ 91.440322] Call Trace:
[ 91.440652] __jbd2_journal_temp_unlink_buffer+0x135/0x220
[ 91.441354] __jbd2_journal_unfile_buffer+0x24/0x90
[ 91.441981] __jbd2_journal_refile_buffer+0x134/0x1d0
[ 91.442628] jbd2_journal_commit_transaction+0x249a/0x3240
[ 91.443336] ? put_prev_entity+0x2a/0x200
[ 91.443856] ? kjournald2+0x12e/0x510
[ 91.444324] kjournald2+0x12e/0x510
[ 91.444773] ? woken_wake_function+0x30/0x30
[ 91.445326] kthread+0x150/0x1b0
[ 91.445739] ? commit_timeout+0x20/0x20
[ 91.446258] ? kthread_flush_worker+0xb0/0xb0
[ 91.446818] ret_from_fork+0x1f/0x30
[ 91.447293] ---[ end trace 66f0b6bf3d1abade ]---
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20210615090537.3423231-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
-rw-r--r-- | fs/ext4/super.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 20344633bdd9..cdbe71d935e8 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -705,15 +705,23 @@ static void flush_stashed_error_work(struct work_struct *work) * ext4 error handling code during handling of previous errors. */ if (!sb_rdonly(sbi->s_sb) && journal) { + struct buffer_head *sbh = sbi->s_sbh; handle = jbd2_journal_start(journal, 1); if (IS_ERR(handle)) goto write_directly; - if (jbd2_journal_get_write_access(handle, sbi->s_sbh)) { + if (jbd2_journal_get_write_access(handle, sbh)) { jbd2_journal_stop(handle); goto write_directly; } ext4_update_super(sbi->s_sb); - if (jbd2_journal_dirty_metadata(handle, sbi->s_sbh)) { + if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) { + ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to " + "superblock detected"); + clear_buffer_write_io_error(sbh); + set_buffer_uptodate(sbh); + } + + if (jbd2_journal_dirty_metadata(handle, sbh)) { jbd2_journal_stop(handle); goto write_directly; } |