From: "Darrick J. Wong" djwong@kernel.org
mainline inclusion from mainline-v5.13-rc1 commit 8e9800f9f2b89e1efe2a5993361fae4d618a6c26 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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While running generic/050 with an external log, I observed this warning in dmesg:
Trying to write to read-only block-device sda4 (partno 4) WARNING: CPU: 2 PID: 215677 at block/blk-core.c:704 submit_bio_checks+0x256/0x510 Call Trace: submit_bio_noacct+0x2c/0x430 _xfs_buf_ioapply+0x283/0x3c0 [xfs] __xfs_buf_submit+0x6a/0x210 [xfs] xfs_buf_delwri_submit_buffers+0xf8/0x270 [xfs] xfsaild+0x2db/0xc50 [xfs] kthread+0x14b/0x170
I think this happened because we tried to cover the log after a readonly mount, and the AIL tried to write the primary superblock to the data device. The test marks the data device readonly, but it doesn't do the same to the external log device. Therefore, XFS thinks that the log is writable, even though AIL writes whine to dmesg because the data device is read only.
Fix this by amending xfs_log_writable to prevent writes when the AIL can't possible write anything into the filesystem.
Note: As for the external log or the rt devices being readonly-- xfs_blkdev_get will complain about that if we aren't doing a norecovery mount.
Signed-off-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Brian Foster bfoster@redhat.com Signed-off-by: yangerkun yangerkun@huaweicloud.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- fs/xfs/xfs_log.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index e154c0d44f9c..7bf94b1d3dbd 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -349,13 +349,15 @@ xfs_log_writable( struct xfs_mount *mp) { /* - * Never write to the log on norecovery mounts, if the block device is - * read-only, or if the filesystem is shutdown. Read-only mounts still - * allow internal writes for log recovery and unmount purposes, so don't - * restrict that case here. + * Do not write to the log on norecovery mounts, if the data or log + * devices are read-only, or if the filesystem is shutdown. Read-only + * mounts allow internal writes for log recovery and unmount purposes, + * so don't restrict that case. */ if (mp->m_flags & XFS_MOUNT_NORECOVERY) return false; + if (xfs_readonly_buftarg(mp->m_ddev_targp)) + return false; if (xfs_readonly_buftarg(mp->m_log->l_targ)) return false; if (XFS_FORCED_SHUTDOWN(mp))