From: Dave Chinner <dchinner@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
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 678ca01047e1..fc893d370b91 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3847,11 +3847,7 @@ 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;
/*
@@ -3860,10 +3856,16 @@ 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);
/*
--
2.35.1
