diff options
| -rw-r--r-- | fs/xfs/xfs_log.c | 55 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 9 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_recover.c | 6 |
3 files changed, 36 insertions, 34 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 1e2020d..70790eb 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -675,12 +675,8 @@ xfs_log_move_tail(xfs_mount_t *mp, if (XLOG_FORCED_SHUTDOWN(log)) return; - if (tail_lsn == 0) { - /* needed since sync_lsn is 64 bits */ - spin_lock(&log->l_icloglock); - tail_lsn = log->l_last_sync_lsn; - spin_unlock(&log->l_icloglock); - } + if (tail_lsn == 0) + tail_lsn = atomic64_read(&log->l_last_sync_lsn); spin_lock(&log->l_grant_lock); @@ -800,11 +796,9 @@ xlog_assign_tail_lsn(xfs_mount_t *mp) tail_lsn = xfs_trans_ail_tail(mp->m_ail); spin_lock(&log->l_grant_lock); - if (tail_lsn != 0) { - log->l_tail_lsn = tail_lsn; - } else { - tail_lsn = log->l_tail_lsn = log->l_last_sync_lsn; - } + if (!tail_lsn) + tail_lsn = atomic64_read(&log->l_last_sync_lsn); + log->l_tail_lsn = tail_lsn; spin_unlock(&log->l_grant_lock); return tail_lsn; @@ -1014,9 +1008,9 @@ xlog_alloc_log(xfs_mount_t *mp, log->l_flags |= XLOG_ACTIVE_RECOVERY; log->l_prev_block = -1; - log->l_tail_lsn = xlog_assign_lsn(1, 0); /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */ - log->l_last_sync_lsn = log->l_tail_lsn; + log->l_tail_lsn = xlog_assign_lsn(1, 0); + atomic64_set(&log->l_last_sync_lsn, xlog_assign_lsn(1, 0)); log->l_curr_cycle = 1; /* 0 is bad since this is initial value */ xlog_assign_grant_head(&log->l_grant_reserve_head, 1, 0); xlog_assign_grant_head(&log->l_grant_write_head, 1, 0); @@ -1194,6 +1188,7 @@ xlog_grant_push_ail( int need_bytes) { xfs_lsn_t threshold_lsn = 0; + xfs_lsn_t last_sync_lsn; xfs_lsn_t tail_lsn; int free_blocks; int free_bytes; @@ -1228,10 +1223,12 @@ xlog_grant_push_ail( threshold_block); /* * Don't pass in an lsn greater than the lsn of the last - * log record known to be on disk. + * log record known to be on disk. Use a snapshot of the last sync lsn + * so that it doesn't change between the compare and the set. */ - if (XFS_LSN_CMP(threshold_lsn, log->l_last_sync_lsn) > 0) - threshold_lsn = log->l_last_sync_lsn; + last_sync_lsn = atomic64_read(&log->l_last_sync_lsn); + if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0) + threshold_lsn = last_sync_lsn; /* * Get the transaction layer to kick the dirty buffers out to @@ -2194,7 +2191,7 @@ xlog_state_do_callback( lowest_lsn = xlog_get_lowest_lsn(log); if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, - be64_to_cpu(iclog->ic_header.h_lsn)) < 0) { + be64_to_cpu(iclog->ic_header.h_lsn)) < 0) { iclog = iclog->ic_next; continue; /* Leave this iclog for * another thread */ @@ -2202,23 +2199,21 @@ xlog_state_do_callback( iclog->ic_state = XLOG_STATE_CALLBACK; - spin_unlock(&log->l_icloglock); - /* l_last_sync_lsn field protected by - * l_grant_lock. Don't worry about iclog's lsn. - * No one else can be here except us. + /* + * update the last_sync_lsn before we drop the + * icloglock to ensure we are the only one that + * can update it. */ - spin_lock(&log->l_grant_lock); - ASSERT(XFS_LSN_CMP(log->l_last_sync_lsn, - be64_to_cpu(iclog->ic_header.h_lsn)) <= 0); - log->l_last_sync_lsn = - be64_to_cpu(iclog->ic_header.h_lsn); - spin_unlock(&log->l_grant_lock); + ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn), + be64_to_cpu(iclog->ic_header.h_lsn)) <= 0); + atomic64_set(&log->l_last_sync_lsn, + be64_to_cpu(iclog->ic_header.h_lsn)); - } else { - spin_unlock(&log->l_icloglock); + } else ioerrors++; - } + + spin_unlock(&log->l_icloglock); /* * Keep processing entries in the callback list until diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index e2bb276..958f356 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -507,7 +507,6 @@ typedef struct log { spinlock_t l_icloglock; /* grab to change iclog state */ xfs_lsn_t l_tail_lsn; /* lsn of 1st LR with unflushed * buffers */ - xfs_lsn_t l_last_sync_lsn;/* lsn of last LR on disk */ int l_curr_cycle; /* Cycle number of log writes */ int l_prev_cycle; /* Cycle number before last * block increment */ @@ -521,6 +520,14 @@ typedef struct log { int64_t l_grant_reserve_head; int64_t l_grant_write_head; + /* + * l_last_sync_lsn is an atomic so it can be set and read without + * needing to hold specific locks. To avoid operations contending with + * other hot objects, place it on a separate cacheline. + */ + /* lsn of last LR on disk */ + atomic64_t l_last_sync_lsn ____cacheline_aligned_in_smp; + /* The following field are used for debugging; need to hold icloglock */ #ifdef DEBUG char *l_iclog_bak[XLOG_MAX_ICLOGS]; diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 1550404..18e1e18 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -937,7 +937,7 @@ xlog_find_tail( if (found == 2) log->l_curr_cycle++; log->l_tail_lsn = be64_to_cpu(rhead->h_tail_lsn); - log->l_last_sync_lsn = be64_to_cpu(rhead->h_lsn); + atomic64_set(&log->l_last_sync_lsn, be64_to_cpu(rhead->h_lsn)); xlog_assign_grant_head(&log->l_grant_reserve_head, log->l_curr_cycle, BBTOB(log->l_curr_block)); xlog_assign_grant_head(&log->l_grant_write_head, log->l_curr_cycle, @@ -989,9 +989,9 @@ xlog_find_tail( log->l_tail_lsn = xlog_assign_lsn(log->l_curr_cycle, after_umount_blk); - log->l_last_sync_lsn = + atomic64_set(&log->l_last_sync_lsn, xlog_assign_lsn(log->l_curr_cycle, - after_umount_blk); + after_umount_blk)); *tail_blk = after_umount_blk; /* |
