diff options
| -rw-r--r-- | fs/xfs/xfs_log.c | 36 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 13 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 3 |
3 files changed, 39 insertions, 13 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 82f5996d3889..e8c6c96d4f7c 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -489,12 +489,17 @@ out_error: /* * Flush iclog to disk if this is the last reference to the given iclog and the - * it is in the WANT_SYNC state. + * it is in the WANT_SYNC state. If the caller passes in a non-zero + * @old_tail_lsn and the current log tail does not match, there may be metadata + * on disk that must be persisted before this iclog is written. To satisfy that + * requirement, set the XLOG_ICL_NEED_FLUSH flag as a condition for writing this + * iclog with the new log tail value. */ int xlog_state_release_iclog( struct xlog *log, - struct xlog_in_core *iclog) + struct xlog_in_core *iclog, + xfs_lsn_t old_tail_lsn) { xfs_lsn_t tail_lsn; lockdep_assert_held(&log->l_icloglock); @@ -503,6 +508,19 @@ xlog_state_release_iclog( if (iclog->ic_state == XLOG_STATE_IOERROR) return -EIO; + /* + * Grabbing the current log tail needs to be atomic w.r.t. the writing + * of the tail LSN into the iclog so we guarantee that the log tail does + * not move between deciding if a cache flush is required and writing + * the LSN into the iclog below. + */ + if (old_tail_lsn || iclog->ic_state == XLOG_STATE_WANT_SYNC) { + tail_lsn = xlog_assign_tail_lsn(log->l_mp); + + if (old_tail_lsn && tail_lsn != old_tail_lsn) + iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; + } + if (!atomic_dec_and_test(&iclog->ic_refcnt)) return 0; @@ -511,8 +529,6 @@ xlog_state_release_iclog( return 0; } - /* update tail before writing to iclog */ - tail_lsn = xlog_assign_tail_lsn(log->l_mp); iclog->ic_state = XLOG_STATE_SYNCING; iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn); xlog_verify_tail_lsn(log, iclog, tail_lsn); @@ -858,7 +874,7 @@ out_err: * iclog containing the unmount record is written. */ iclog->ic_flags |= (XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA); - error = xlog_state_release_iclog(log, iclog); + error = xlog_state_release_iclog(log, iclog, 0); xlog_wait_on_iclog(iclog); if (tic) { @@ -2302,7 +2318,7 @@ xlog_write_copy_finish( return 0; release_iclog: - error = xlog_state_release_iclog(log, iclog); + error = xlog_state_release_iclog(log, iclog, 0); spin_unlock(&log->l_icloglock); return error; } @@ -2521,7 +2537,7 @@ next_lv: ASSERT(optype & XLOG_COMMIT_TRANS); *commit_iclog = iclog; } else { - error = xlog_state_release_iclog(log, iclog); + error = xlog_state_release_iclog(log, iclog, 0); } spin_unlock(&log->l_icloglock); @@ -2959,7 +2975,7 @@ restart: * reference to the iclog. */ if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) - error = xlog_state_release_iclog(log, iclog); + error = xlog_state_release_iclog(log, iclog, 0); spin_unlock(&log->l_icloglock); if (error) return error; @@ -3195,7 +3211,7 @@ xfs_log_force( atomic_inc(&iclog->ic_refcnt); lsn = be64_to_cpu(iclog->ic_header.h_lsn); xlog_state_switch_iclogs(log, iclog, 0); - if (xlog_state_release_iclog(log, iclog)) + if (xlog_state_release_iclog(log, iclog, 0)) goto out_error; if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) @@ -3275,7 +3291,7 @@ xlog_force_lsn( } atomic_inc(&iclog->ic_refcnt); xlog_state_switch_iclogs(log, iclog, 0); - if (xlog_state_release_iclog(log, iclog)) + if (xlog_state_release_iclog(log, iclog, 0)) goto out_error; if (log_flushed) *log_flushed = 1; diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index b128aaa9b870..4c44bc3786c0 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -654,8 +654,9 @@ xlog_cil_push_work( struct xfs_trans_header thdr; struct xfs_log_iovec lhdr; struct xfs_log_vec lvhdr = { NULL }; + xfs_lsn_t preflush_tail_lsn; xfs_lsn_t commit_lsn; - xfs_lsn_t push_seq; + xfs_csn_t push_seq; struct bio bio; DECLARE_COMPLETION_ONSTACK(bdev_flush); @@ -730,7 +731,15 @@ xlog_cil_push_work( * because we hold the flush lock exclusively. Hence we can now issue * a cache flush to ensure all the completed metadata in the journal we * are about to overwrite is on stable storage. + * + * Because we are issuing this cache flush before we've written the + * tail lsn to the iclog, we can have metadata IO completions move the + * tail forwards between the completion of this flush and the iclog + * being written. In this case, we need to re-issue the cache flush + * before the iclog write. To detect whether the log tail moves, sample + * the tail LSN *before* we issue the flush. */ + preflush_tail_lsn = atomic64_read(&log->l_tail_lsn); xfs_flush_bdev_async(&bio, log->l_mp->m_ddev_targp->bt_bdev, &bdev_flush); @@ -941,7 +950,7 @@ restart: * storage. */ commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA; - xlog_state_release_iclog(log, commit_iclog); + xlog_state_release_iclog(log, commit_iclog, preflush_tail_lsn); spin_unlock(&log->l_icloglock); return; diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 4c41bbfa33b0..7cbde0b4f990 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -497,7 +497,8 @@ int xlog_commit_record(struct xlog *log, struct xlog_ticket *ticket, void xfs_log_ticket_ungrant(struct xlog *log, struct xlog_ticket *ticket); void xfs_log_ticket_regrant(struct xlog *log, struct xlog_ticket *ticket); -int xlog_state_release_iclog(struct xlog *log, struct xlog_in_core *iclog); +int xlog_state_release_iclog(struct xlog *log, struct xlog_in_core *iclog, + xfs_lsn_t log_tail_lsn); /* * When we crack an atomic LSN, we sample it first so that the value will not |