From: Dave Chinner dchinner@redhat.com
mainline inclusion from mainline-v5.17-rc6 commit 5652ef31705f240e1528fe5a45d99229752e1ec8 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I76JSK CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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When a checkpoint writeback is run by log recovery, corruption propagated from the log can result in writeback verifiers failing and calling xfs_force_shutdown() from xfs_buf_delwri_submit_buffers().
This results in the mount being marked as shutdown, but the log does not get marked as shut down because:
/* * If this happens during log recovery then we aren't using the runtime * log mechanisms yet so there's nothing to shut down. */ if (!log || xlog_in_recovery(log)) return false;
If there are other buffers that then fail (say due to detecting the mount shutdown), they will now hang in xfs_do_force_shutdown() waiting for the log to shut down like this:
__schedule+0x30d/0x9e0 schedule+0x55/0xd0 xfs_do_force_shutdown+0x1cd/0x200 ? init_wait_var_entry+0x50/0x50 xfs_buf_ioend+0x47e/0x530 __xfs_buf_submit+0xb0/0x240 xfs_buf_delwri_submit_buffers+0xfe/0x270 xfs_buf_delwri_submit+0x3a/0xc0 xlog_do_recovery_pass+0x474/0x7b0 ? do_raw_spin_unlock+0x30/0xb0 xlog_do_log_recovery+0x91/0x140 xlog_do_recover+0x38/0x1e0 xlog_recover+0xdd/0x170 xfs_log_mount+0x17e/0x2e0 xfs_mountfs+0x457/0x930 xfs_fs_fill_super+0x476/0x830
xlog_force_shutdown() always needs to mark the log as shut down, regardless of whether recovery is in progress or not, so that multiple calls to xfs_force_shutdown() during recovery don't end up waiting for the log to be shut down like this.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Long Li leo.lilong@huawei.com --- fs/xfs/xfs_log.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 544539ab3c94..506bb43b1eda 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3755,11 +3755,7 @@ xlog_force_shutdown( { bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
- /* - * If this happens during log recovery then we aren't using the runtime - * log mechanisms yet so there's nothing to shut down. - */ - if (!log || xlog_in_recovery(log)) + if (!log) return false;
/* @@ -3768,10 +3764,16 @@ xlog_force_shutdown( * before the force will prevent the log force from flushing the iclogs * to disk. * - * Re-entry due to a log IO error shutdown during the log force is - * prevented by the atomicity of higher level shutdown code. + * When we are in recovery, there are no transactions to flush, and + * we don't want to touch the log because we don't want to perturb the + * current head/tail for future recovery attempts. Hence we need to + * avoid a log force in this case. + * + * If we are shutting down due to a log IO error, then we must avoid + * trying to write the log as that may just result in more IO errors and + * an endless shutdown/force loop. */ - if (!log_error) + if (!log_error && !xlog_in_recovery(log)) xfs_log_force(log->l_mp, XFS_LOG_SYNC);
/*