diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h index 3ff6b35f92072b1fe1c0d96fc357fbaea06198d7..b180e1bf8257a0f1fce9da0e7c62b2284e21ee54 100644 --- a/fs/xfs/linux-2.6/xfs_trace.h +++ b/fs/xfs/linux-2.6/xfs_trace.h @@ -794,7 +794,7 @@ DECLARE_EVENT_CLASS(xfs_loggrant_class, &__entry->grant_write_bytes); __entry->curr_cycle = log->l_curr_cycle; __entry->curr_block = log->l_curr_block; - __entry->tail_lsn = log->l_tail_lsn; + __entry->tail_lsn = atomic64_read(&log->l_tail_lsn); ), TP_printk("dev %d:%d type %s t_ocnt %u t_cnt %u t_curr_res %u " "t_unit_res %u t_flags %s reserveq %s " diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 70790eb48336b78a683192338ae36efc3ef392d5..d118bf8044809734d75c77a99244014062ecebc6 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -678,15 +678,11 @@ xfs_log_move_tail(xfs_mount_t *mp, if (tail_lsn == 0) tail_lsn = atomic64_read(&log->l_last_sync_lsn); - spin_lock(&log->l_grant_lock); - - /* Also an invalid lsn. 1 implies that we aren't passing in a valid - * tail_lsn. - */ - if (tail_lsn != 1) { - log->l_tail_lsn = tail_lsn; - } + /* tail_lsn == 1 implies that we weren't passed a valid value. */ + if (tail_lsn != 1) + atomic64_set(&log->l_tail_lsn, tail_lsn); + spin_lock(&log->l_grant_lock); if (!list_empty(&log->l_writeq)) { #ifdef DEBUG if (log->l_flags & XLOG_ACTIVE_RECOVERY) @@ -789,21 +785,19 @@ xfs_log_need_covered(xfs_mount_t *mp) * We may be holding the log iclog lock upon entering this routine. */ xfs_lsn_t -xlog_assign_tail_lsn(xfs_mount_t *mp) +xlog_assign_tail_lsn( + struct xfs_mount *mp) { - xfs_lsn_t tail_lsn; - xlog_t *log = mp->m_log; + xfs_lsn_t tail_lsn; + struct log *log = mp->m_log; tail_lsn = xfs_trans_ail_tail(mp->m_ail); - spin_lock(&log->l_grant_lock); if (!tail_lsn) tail_lsn = atomic64_read(&log->l_last_sync_lsn); - log->l_tail_lsn = tail_lsn; - spin_unlock(&log->l_grant_lock); + atomic64_set(&log->l_tail_lsn, tail_lsn); return tail_lsn; -} /* xlog_assign_tail_lsn */ - +} /* * Return the space in the log between the tail and the head. The head @@ -831,8 +825,8 @@ xlog_space_left( int head_bytes; xlog_crack_grant_head(head, &head_cycle, &head_bytes); - tail_bytes = BBTOB(BLOCK_LSN(log->l_tail_lsn)); - tail_cycle = CYCLE_LSN(log->l_tail_lsn); + xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes); + tail_bytes = BBTOB(tail_bytes); if (tail_cycle == head_cycle && head_bytes >= tail_bytes) free_bytes = log->l_logsize - (head_bytes - tail_bytes); else if (tail_cycle + 1 < head_cycle) @@ -1009,8 +1003,8 @@ xlog_alloc_log(xfs_mount_t *mp, log->l_prev_block = -1; /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */ - log->l_tail_lsn = xlog_assign_lsn(1, 0); - atomic64_set(&log->l_last_sync_lsn, xlog_assign_lsn(1, 0)); + xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0); + xlog_assign_atomic_lsn(&log->l_last_sync_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); @@ -1189,7 +1183,6 @@ xlog_grant_push_ail( { xfs_lsn_t threshold_lsn = 0; xfs_lsn_t last_sync_lsn; - xfs_lsn_t tail_lsn; int free_blocks; int free_bytes; int threshold_block; @@ -1198,7 +1191,6 @@ xlog_grant_push_ail( ASSERT(BTOBB(need_bytes) < log->l_logBBsize); - tail_lsn = log->l_tail_lsn; free_bytes = xlog_space_left(log, &log->l_grant_reserve_head); free_blocks = BTOBBT(free_bytes); @@ -1213,8 +1205,9 @@ xlog_grant_push_ail( if (free_blocks >= free_threshold) return; - threshold_block = BLOCK_LSN(tail_lsn) + free_threshold; - threshold_cycle = CYCLE_LSN(tail_lsn); + xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle, + &threshold_block); + threshold_block += free_threshold; if (threshold_block >= log->l_logBBsize) { threshold_block -= log->l_logBBsize; threshold_cycle += 1; @@ -2828,11 +2821,11 @@ xlog_state_release_iclog( if (iclog->ic_state == XLOG_STATE_WANT_SYNC) { /* update tail before writing to iclog */ - xlog_assign_tail_lsn(log->l_mp); + xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp); sync++; iclog->ic_state = XLOG_STATE_SYNCING; - iclog->ic_header.h_tail_lsn = cpu_to_be64(log->l_tail_lsn); - xlog_verify_tail_lsn(log, iclog, log->l_tail_lsn); + iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn); + xlog_verify_tail_lsn(log, iclog, tail_lsn); /* cycle incremented when incrementing curr_block */ } spin_unlock(&log->l_icloglock); @@ -3435,7 +3428,7 @@ STATIC void xlog_verify_grant_tail( struct log *log) { - xfs_lsn_t tail_lsn = log->l_tail_lsn; + int tail_cycle, tail_blocks; int cycle, space; /* @@ -3445,9 +3438,10 @@ xlog_verify_grant_tail( * check the byte count. */ xlog_crack_grant_head(&log->l_grant_write_head, &cycle, &space); - if (CYCLE_LSN(tail_lsn) != cycle) { - ASSERT(cycle - 1 == CYCLE_LSN(tail_lsn)); - ASSERT(space <= BBTOB(BLOCK_LSN(tail_lsn))); + xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks); + if (tail_cycle != cycle) { + ASSERT(cycle - 1 == tail_cycle); + ASSERT(space <= BBTOB(tail_blocks)); } } diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 958f356df10ed51cb6c33297554adc127c3b7657..d34af1c21ed275036e94594853d2d5827c54f8ac 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -53,7 +53,6 @@ struct xfs_mount; BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \ XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT)) - static inline xfs_lsn_t xlog_assign_lsn(uint cycle, uint block) { return ((xfs_lsn_t)cycle << 32) | block; @@ -505,8 +504,6 @@ typedef struct log { * log entries" */ xlog_in_core_t *l_iclog; /* head log queue */ spinlock_t l_icloglock; /* grab to change iclog state */ - xfs_lsn_t l_tail_lsn; /* lsn of 1st LR with unflushed - * buffers */ int l_curr_cycle; /* Cycle number of log writes */ int l_prev_cycle; /* Cycle number before last * block increment */ @@ -521,12 +518,15 @@ typedef struct log { 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. + * l_last_sync_lsn and l_tail_lsn are atomics so they can be set and + * read without needing to hold specific locks. To avoid operations + * contending with other hot objects, place each of them on a separate + * cacheline. */ /* lsn of last LR on disk */ atomic64_t l_last_sync_lsn ____cacheline_aligned_in_smp; + /* lsn of 1st LR with unflushed * buffers */ + atomic64_t l_tail_lsn ____cacheline_aligned_in_smp; /* The following field are used for debugging; need to hold icloglock */ #ifdef DEBUG @@ -565,6 +565,31 @@ int xlog_write(struct log *log, struct xfs_log_vec *log_vector, struct xlog_ticket *tic, xfs_lsn_t *start_lsn, xlog_in_core_t **commit_iclog, uint flags); +/* + * When we crack an atomic LSN, we sample it first so that the value will not + * change while we are cracking it into the component values. This means we + * will always get consistent component values to work from. This should always + * be used to smaple and crack LSNs taht are stored and updated in atomic + * variables. + */ +static inline void +xlog_crack_atomic_lsn(atomic64_t *lsn, uint *cycle, uint *block) +{ + xfs_lsn_t val = atomic64_read(lsn); + + *cycle = CYCLE_LSN(val); + *block = BLOCK_LSN(val); +} + +/* + * Calculate and assign a value to an atomic LSN variable from component pieces. + */ +static inline void +xlog_assign_atomic_lsn(atomic64_t *lsn, uint cycle, uint block) +{ + atomic64_set(lsn, xlog_assign_lsn(cycle, block)); +} + /* * When we crack the grrant head, we sample it first so that the value will not * change while we are cracking it into the component values. This means we diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 18e1e18d7147173731df2a279f7fd43313016454..204d8e5fa7faf63ada5fc2135fefc2b7330d34ec 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -936,7 +936,7 @@ xlog_find_tail( log->l_curr_cycle = be32_to_cpu(rhead->h_cycle); if (found == 2) log->l_curr_cycle++; - log->l_tail_lsn = be64_to_cpu(rhead->h_tail_lsn); + atomic64_set(&log->l_tail_lsn, be64_to_cpu(rhead->h_tail_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)); @@ -971,7 +971,7 @@ xlog_find_tail( } after_umount_blk = (i + hblks + (int) BTOBB(be32_to_cpu(rhead->h_len))) % log->l_logBBsize; - tail_lsn = log->l_tail_lsn; + tail_lsn = atomic64_read(&log->l_tail_lsn); if (*head_blk == after_umount_blk && be32_to_cpu(rhead->h_num_logops) == 1) { umount_data_blk = (i + hblks) % log->l_logBBsize; @@ -986,12 +986,10 @@ xlog_find_tail( * log records will point recovery to after the * current unmount record. */ - log->l_tail_lsn = - xlog_assign_lsn(log->l_curr_cycle, - after_umount_blk); - atomic64_set(&log->l_last_sync_lsn, - xlog_assign_lsn(log->l_curr_cycle, - after_umount_blk)); + xlog_assign_atomic_lsn(&log->l_tail_lsn, + log->l_curr_cycle, after_umount_blk); + xlog_assign_atomic_lsn(&log->l_last_sync_lsn, + log->l_curr_cycle, after_umount_blk); *tail_blk = after_umount_blk; /*