From a69ed03c24d4a336c23b7116127713d5a8c5ac4d Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 21 Dec 2010 12:08:20 +1100 Subject: [PATCH] xfs: combine grant heads into a single 64 bit integer Prepare for switching the grant heads to atomic variables by combining the two 32 bit values that make up the grant head into a single 64 bit variable. Provide wrapper functions to combine and split the grant heads appropriately for calculations and use them as necessary. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_trace.h | 10 ++- fs/xfs/xfs_log.c | 166 ++++++++++++++++++----------------- fs/xfs/xfs_log_priv.h | 26 +++++- fs/xfs/xfs_log_recover.c | 8 +- 4 files changed, 119 insertions(+), 91 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h index 69b9e1f1baaf..3ff6b35f9207 100644 --- a/fs/xfs/linux-2.6/xfs_trace.h +++ b/fs/xfs/linux-2.6/xfs_trace.h @@ -786,10 +786,12 @@ DECLARE_EVENT_CLASS(xfs_loggrant_class, __entry->flags = tic->t_flags; __entry->reserveq = list_empty(&log->l_reserveq); __entry->writeq = list_empty(&log->l_writeq); - __entry->grant_reserve_cycle = log->l_grant_reserve_cycle; - __entry->grant_reserve_bytes = log->l_grant_reserve_bytes; - __entry->grant_write_cycle = log->l_grant_write_cycle; - __entry->grant_write_bytes = log->l_grant_write_bytes; + xlog_crack_grant_head(&log->l_grant_reserve_head, + &__entry->grant_reserve_cycle, + &__entry->grant_reserve_bytes); + xlog_crack_grant_head(&log->l_grant_write_head, + &__entry->grant_write_cycle, + &__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; diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 9a4b9edad847..6bba8b4b8596 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -47,7 +47,7 @@ STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp, xfs_buftarg_t *log_target, xfs_daddr_t blk_offset, int num_bblks); -STATIC int xlog_space_left(xlog_t *log, int cycle, int bytes); +STATIC int xlog_space_left(struct log *log, int64_t *head); STATIC int xlog_sync(xlog_t *log, xlog_in_core_t *iclog); STATIC void xlog_dealloc_log(xlog_t *log); @@ -100,32 +100,44 @@ STATIC int xlog_iclogs_empty(xlog_t *log); static void xlog_grant_sub_space( struct log *log, - int *cycle, - int *space, + int64_t *head, int bytes) { - *space -= bytes; - if (*space < 0) { - *space += log->l_logsize; - (*cycle)--; + int cycle, space; + + xlog_crack_grant_head(head, &cycle, &space); + + space -= bytes; + if (space < 0) { + space += log->l_logsize; + cycle--; } + + xlog_assign_grant_head(head, cycle, space); } static void xlog_grant_add_space( struct log *log, - int *cycle, - int *space, + int64_t *head, int bytes) { - int tmp = log->l_logsize - *space; + int tmp; + int cycle, space; + + xlog_crack_grant_head(head, &cycle, &space); + + tmp = log->l_logsize - space; if (tmp > bytes) - *space += bytes; + space += bytes; else { - *space = bytes - tmp; - (*cycle)++; + space = bytes - tmp; + cycle++; } + + xlog_assign_grant_head(head, cycle, space); } + static void xlog_tic_reset_res(xlog_ticket_t *tic) { @@ -654,7 +666,7 @@ xfs_log_move_tail(xfs_mount_t *mp, { xlog_ticket_t *tic; xlog_t *log = mp->m_log; - int need_bytes, free_bytes, cycle, bytes; + int need_bytes, free_bytes; if (XLOG_FORCED_SHUTDOWN(log)) return; @@ -680,9 +692,7 @@ xfs_log_move_tail(xfs_mount_t *mp, if (log->l_flags & XLOG_ACTIVE_RECOVERY) panic("Recovery problem"); #endif - cycle = log->l_grant_write_cycle; - bytes = log->l_grant_write_bytes; - free_bytes = xlog_space_left(log, cycle, bytes); + free_bytes = xlog_space_left(log, &log->l_grant_write_head); list_for_each_entry(tic, &log->l_writeq, t_queue) { ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV); @@ -699,9 +709,7 @@ xfs_log_move_tail(xfs_mount_t *mp, if (log->l_flags & XLOG_ACTIVE_RECOVERY) panic("Recovery problem"); #endif - cycle = log->l_grant_reserve_cycle; - bytes = log->l_grant_reserve_bytes; - free_bytes = xlog_space_left(log, cycle, bytes); + free_bytes = xlog_space_left(log, &log->l_grant_reserve_head); list_for_each_entry(tic, &log->l_reserveq, t_queue) { if (tic->t_flags & XLOG_TIC_PERM_RESERV) need_bytes = tic->t_unit_res*tic->t_cnt; @@ -814,21 +822,26 @@ xlog_assign_tail_lsn(xfs_mount_t *mp) * result is that we return the size of the log as the amount of space left. */ STATIC int -xlog_space_left(xlog_t *log, int cycle, int bytes) +xlog_space_left( + struct log *log, + int64_t *head) { - int free_bytes; - int tail_bytes; - int tail_cycle; + int free_bytes; + int tail_bytes; + int tail_cycle; + int head_cycle; + 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); - if ((tail_cycle == cycle) && (bytes >= tail_bytes)) { - free_bytes = log->l_logsize - (bytes - tail_bytes); - } else if ((tail_cycle + 1) < cycle) { + 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) return 0; - } else if (tail_cycle < cycle) { - ASSERT(tail_cycle == (cycle - 1)); - free_bytes = tail_bytes - bytes; + else if (tail_cycle < head_cycle) { + ASSERT(tail_cycle == (head_cycle - 1)); + free_bytes = tail_bytes - head_bytes; } else { /* * The reservation head is behind the tail. @@ -839,12 +852,12 @@ xlog_space_left(xlog_t *log, int cycle, int bytes) "xlog_space_left: head behind tail\n" " tail_cycle = %d, tail_bytes = %d\n" " GH cycle = %d, GH bytes = %d", - tail_cycle, tail_bytes, cycle, bytes); + tail_cycle, tail_bytes, head_cycle, head_bytes); ASSERT(0); free_bytes = log->l_logsize; } return free_bytes; -} /* xlog_space_left */ +} /* @@ -1001,8 +1014,8 @@ xlog_alloc_log(xfs_mount_t *mp, /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */ log->l_last_sync_lsn = log->l_tail_lsn; log->l_curr_cycle = 1; /* 0 is bad since this is initial value */ - log->l_grant_reserve_cycle = 1; - log->l_grant_write_cycle = 1; + xlog_assign_grant_head(&log->l_grant_reserve_head, 1, 0); + xlog_assign_grant_head(&log->l_grant_write_head, 1, 0); INIT_LIST_HEAD(&log->l_reserveq); INIT_LIST_HEAD(&log->l_writeq); @@ -1190,9 +1203,7 @@ xlog_grant_push_ail(xfs_mount_t *mp, ASSERT(BTOBB(need_bytes) < log->l_logBBsize); spin_lock(&log->l_grant_lock); - free_bytes = xlog_space_left(log, - log->l_grant_reserve_cycle, - log->l_grant_reserve_bytes); + free_bytes = xlog_space_left(log, &log->l_grant_reserve_head); tail_lsn = log->l_tail_lsn; free_blocks = BTOBBT(free_bytes); @@ -1325,10 +1336,8 @@ xlog_sync(xlog_t *log, /* move grant heads by roundoff in sync */ spin_lock(&log->l_grant_lock); - xlog_grant_add_space(log, &log->l_grant_reserve_cycle, - &log->l_grant_reserve_bytes, roundoff); - xlog_grant_add_space(log, &log->l_grant_write_cycle, - &log->l_grant_write_bytes, roundoff); + xlog_grant_add_space(log, &log->l_grant_reserve_head, roundoff); + xlog_grant_add_space(log, &log->l_grant_write_head, roundoff); spin_unlock(&log->l_grant_lock); /* put cycle number in every block */ @@ -2531,8 +2540,7 @@ xlog_grant_log_space(xlog_t *log, if (XLOG_FORCED_SHUTDOWN(log)) goto error_return; - free_bytes = xlog_space_left(log, log->l_grant_reserve_cycle, - log->l_grant_reserve_bytes); + free_bytes = xlog_space_left(log, &log->l_grant_reserve_head); if (free_bytes < need_bytes) { if (list_empty(&tic->t_queue)) list_add_tail(&tic->t_queue, &log->l_reserveq); @@ -2558,10 +2566,8 @@ xlog_grant_log_space(xlog_t *log, list_del_init(&tic->t_queue); /* we've got enough space */ - xlog_grant_add_space(log, &log->l_grant_reserve_cycle, - &log->l_grant_reserve_bytes, need_bytes); - xlog_grant_add_space(log, &log->l_grant_write_cycle, - &log->l_grant_write_bytes, need_bytes); + xlog_grant_add_space(log, &log->l_grant_reserve_head, need_bytes); + xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes); trace_xfs_log_grant_exit(log, tic); xlog_verify_grant_head(log, 1); xlog_verify_grant_tail(log); @@ -2622,8 +2628,7 @@ xlog_regrant_write_log_space(xlog_t *log, need_bytes = tic->t_unit_res; if (!list_empty(&log->l_writeq)) { struct xlog_ticket *ntic; - free_bytes = xlog_space_left(log, log->l_grant_write_cycle, - log->l_grant_write_bytes); + free_bytes = xlog_space_left(log, &log->l_grant_write_head); list_for_each_entry(ntic, &log->l_writeq, t_queue) { ASSERT(ntic->t_flags & XLOG_TIC_PERM_RESERV); @@ -2662,8 +2667,7 @@ xlog_regrant_write_log_space(xlog_t *log, if (XLOG_FORCED_SHUTDOWN(log)) goto error_return; - free_bytes = xlog_space_left(log, log->l_grant_write_cycle, - log->l_grant_write_bytes); + free_bytes = xlog_space_left(log, &log->l_grant_write_head); if (free_bytes < need_bytes) { if (list_empty(&tic->t_queue)) list_add_tail(&tic->t_queue, &log->l_writeq); @@ -2688,8 +2692,7 @@ xlog_regrant_write_log_space(xlog_t *log, list_del_init(&tic->t_queue); /* we've got enough space */ - xlog_grant_add_space(log, &log->l_grant_write_cycle, - &log->l_grant_write_bytes, need_bytes); + xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes); trace_xfs_log_regrant_write_exit(log, tic); xlog_verify_grant_head(log, 1); xlog_verify_grant_tail(log); @@ -2730,12 +2733,10 @@ xlog_regrant_reserve_log_space(xlog_t *log, ticket->t_cnt--; spin_lock(&log->l_grant_lock); - xlog_grant_sub_space(log, &log->l_grant_reserve_cycle, - &log->l_grant_reserve_bytes, - ticket->t_curr_res); - xlog_grant_sub_space(log, &log->l_grant_write_cycle, - &log->l_grant_write_bytes, - ticket->t_curr_res); + xlog_grant_sub_space(log, &log->l_grant_reserve_head, + ticket->t_curr_res); + xlog_grant_sub_space(log, &log->l_grant_write_head, + ticket->t_curr_res); ticket->t_curr_res = ticket->t_unit_res; xlog_tic_reset_res(ticket); @@ -2749,9 +2750,8 @@ xlog_regrant_reserve_log_space(xlog_t *log, return; } - xlog_grant_add_space(log, &log->l_grant_reserve_cycle, - &log->l_grant_reserve_bytes, - ticket->t_unit_res); + xlog_grant_add_space(log, &log->l_grant_reserve_head, + ticket->t_unit_res); trace_xfs_log_regrant_reserve_exit(log, ticket); @@ -2799,10 +2799,8 @@ xlog_ungrant_log_space(xlog_t *log, bytes += ticket->t_unit_res*ticket->t_cnt; } - xlog_grant_sub_space(log, &log->l_grant_reserve_cycle, - &log->l_grant_reserve_bytes, bytes); - xlog_grant_sub_space(log, &log->l_grant_write_cycle, - &log->l_grant_write_bytes, bytes); + xlog_grant_sub_space(log, &log->l_grant_reserve_head, bytes); + xlog_grant_sub_space(log, &log->l_grant_write_head, bytes); trace_xfs_log_ungrant_exit(log, ticket); @@ -3430,22 +3428,31 @@ xlog_verify_dest_ptr( STATIC void xlog_verify_grant_head(xlog_t *log, int equals) { - if (log->l_grant_reserve_cycle == log->l_grant_write_cycle) { - if (equals) - ASSERT(log->l_grant_reserve_bytes >= log->l_grant_write_bytes); - else - ASSERT(log->l_grant_reserve_bytes > log->l_grant_write_bytes); - } else { - ASSERT(log->l_grant_reserve_cycle-1 == log->l_grant_write_cycle); - ASSERT(log->l_grant_write_bytes >= log->l_grant_reserve_bytes); - } -} /* xlog_verify_grant_head */ + int reserve_cycle, reserve_space; + int write_cycle, write_space; + + xlog_crack_grant_head(&log->l_grant_reserve_head, + &reserve_cycle, &reserve_space); + xlog_crack_grant_head(&log->l_grant_write_head, + &write_cycle, &write_space); + + if (reserve_cycle == write_cycle) { + if (equals) + ASSERT(reserve_space >= write_space); + else + ASSERT(reserve_space > write_space); + } else { + ASSERT(reserve_cycle - 1 == write_cycle); + ASSERT(write_space >= reserve_space); + } +} STATIC void xlog_verify_grant_tail( struct log *log) { xfs_lsn_t tail_lsn = log->l_tail_lsn; + int cycle, space; /* * Check to make sure the grant write head didn't just over lap the @@ -3453,9 +3460,10 @@ xlog_verify_grant_tail( * Otherwise, make sure that the cycles differ by exactly one and * check the byte count. */ - if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) { - ASSERT(log->l_grant_write_cycle - 1 == CYCLE_LSN(tail_lsn)); - ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn))); + 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))); } } diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index a5b3c021a406..2f74c80a7a40 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -518,10 +518,8 @@ typedef struct log { spinlock_t l_grant_lock ____cacheline_aligned_in_smp; struct list_head l_reserveq; struct list_head l_writeq; - int l_grant_reserve_cycle; - int l_grant_reserve_bytes; - int l_grant_write_cycle; - int l_grant_write_bytes; + int64_t l_grant_reserve_head; + int64_t l_grant_write_head; /* The following field are used for debugging; need to hold icloglock */ #ifdef DEBUG @@ -560,6 +558,26 @@ 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 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 + * will always get consistent component values to work from. + */ +static inline void +xlog_crack_grant_head(int64_t *head, int *cycle, int *space) +{ + int64_t val = *head; + + *cycle = val >> 32; + *space = val & 0xffffffff; +} + +static inline void +xlog_assign_grant_head(int64_t *head, int cycle, int space) +{ + *head = ((int64_t)cycle << 32) | space; +} + /* * Committed Item List interfaces */ diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 4abe7a9b380e..1550404a8aeb 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -938,10 +938,10 @@ xlog_find_tail( 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); - log->l_grant_reserve_cycle = log->l_curr_cycle; - log->l_grant_reserve_bytes = BBTOB(log->l_curr_block); - log->l_grant_write_cycle = log->l_curr_cycle; - log->l_grant_write_bytes = BBTOB(log->l_curr_block); + 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, + BBTOB(log->l_curr_block)); /* * Look for unmount record. If we find it, then we know there -- GitLab