xfs: add the xlog_grant_head structure

Add a new data structure to allow sharing code between the log grant and
regrant code.

Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

4 files changed, 74 insertions, 73 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 02a35fba5eae..ad0cac378e9a 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -158,7 +158,7 @@ xlog_reserveq_wake(
         struct xlog_ticket      *tic;
         int                     need_bytes;
 
-        list_for_each_entry(tic, &log->l_reserveq, t_queue) {
+        list_for_each_entry(tic, &log->l_reserve_head.waiters, t_queue) {
                 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
                         need_bytes = tic->t_unit_res * tic->t_cnt;
                 else
@@ -183,7 +183,7 @@ xlog_writeq_wake(
         struct xlog_ticket      *tic;
         int                     need_bytes;
 
-        list_for_each_entry(tic, &log->l_writeq, t_queue) {
+        list_for_each_entry(tic, &log->l_write_head.waiters, t_queue) {
                 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
 
                 need_bytes = tic->t_unit_res;
@@ -205,7 +205,7 @@ xlog_reserveq_wait(
         struct xlog_ticket      *tic,
         int                     need_bytes)
 {
-        list_add_tail(&tic->t_queue, &log->l_reserveq);
+        list_add_tail(&tic->t_queue, &log->l_reserve_head.waiters);
 
         do {
                 if (XLOG_FORCED_SHUTDOWN(log))
@@ -213,7 +213,7 @@ xlog_reserveq_wait(
                 xlog_grant_push_ail(log, need_bytes);
 
                 __set_current_state(TASK_UNINTERRUPTIBLE);
-                spin_unlock(&log->l_grant_reserve_lock);
+                spin_unlock(&log->l_reserve_head.lock);
 
                 XFS_STATS_INC(xs_sleep_logspace);
 
@@ -221,10 +221,10 @@ xlog_reserveq_wait(
                 schedule();
                 trace_xfs_log_grant_wake(log, tic);
 
-                spin_lock(&log->l_grant_reserve_lock);
+                spin_lock(&log->l_reserve_head.lock);
                 if (XLOG_FORCED_SHUTDOWN(log))
                         goto shutdown;
-        } while (xlog_space_left(log, &log->l_grant_reserve_head) < need_bytes);
+        } while (xlog_space_left(log, &log->l_reserve_head.grant) < need_bytes);
 
         list_del_init(&tic->t_queue);
         return 0;
@@ -239,7 +239,7 @@ xlog_writeq_wait(
         struct xlog_ticket      *tic,
         int                     need_bytes)
 {
-        list_add_tail(&tic->t_queue, &log->l_writeq);
+        list_add_tail(&tic->t_queue, &log->l_write_head.waiters);
 
         do {
                 if (XLOG_FORCED_SHUTDOWN(log))
@@ -247,7 +247,7 @@ xlog_writeq_wait(
                 xlog_grant_push_ail(log, need_bytes);
 
                 __set_current_state(TASK_UNINTERRUPTIBLE);
-                spin_unlock(&log->l_grant_write_lock);
+                spin_unlock(&log->l_write_head.lock);
 
                 XFS_STATS_INC(xs_sleep_logspace);
 
@@ -255,10 +255,10 @@ xlog_writeq_wait(
                 schedule();
                 trace_xfs_log_regrant_write_wake(log, tic);
 
-                spin_lock(&log->l_grant_write_lock);
+                spin_lock(&log->l_write_head.lock);
                 if (XLOG_FORCED_SHUTDOWN(log))
                         goto shutdown;
-        } while (xlog_space_left(log, &log->l_grant_write_head) < need_bytes);
+        } while (xlog_space_left(log, &log->l_write_head.grant) < need_bytes);
 
         list_del_init(&tic->t_queue);
         return 0;
@@ -779,22 +779,22 @@ xfs_log_space_wake(
         if (XLOG_FORCED_SHUTDOWN(log))
                 return;
 
-        if (!list_empty_careful(&log->l_writeq)) {
+        if (!list_empty_careful(&log->l_write_head.waiters)) {
                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 
-                spin_lock(&log->l_grant_write_lock);
-                free_bytes = xlog_space_left(log, &log->l_grant_write_head);
+                spin_lock(&log->l_write_head.lock);
+                free_bytes = xlog_space_left(log, &log->l_write_head.grant);
                 xlog_writeq_wake(log, &free_bytes);
-                spin_unlock(&log->l_grant_write_lock);
+                spin_unlock(&log->l_write_head.lock);
         }
 
-        if (!list_empty_careful(&log->l_reserveq)) {
+        if (!list_empty_careful(&log->l_reserve_head.waiters)) {
                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 
-                spin_lock(&log->l_grant_reserve_lock);
-                free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
+                spin_lock(&log->l_reserve_head.lock);
+                free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
                 xlog_reserveq_wake(log, &free_bytes);
-                spin_unlock(&log->l_grant_reserve_lock);
+                spin_unlock(&log->l_reserve_head.lock);
         }
 }
 
@@ -1070,12 +1070,12 @@ xlog_alloc_log(xfs_mount_t	*mp,
         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);
-        INIT_LIST_HEAD(&log->l_reserveq);
-        INIT_LIST_HEAD(&log->l_writeq);
-        spin_lock_init(&log->l_grant_reserve_lock);
-        spin_lock_init(&log->l_grant_write_lock);
+        xlog_assign_grant_head(&log->l_reserve_head.grant, 1, 0);
+        xlog_assign_grant_head(&log->l_write_head.grant, 1, 0);
+        INIT_LIST_HEAD(&log->l_reserve_head.waiters);
+        INIT_LIST_HEAD(&log->l_write_head.waiters);
+        spin_lock_init(&log->l_reserve_head.lock);
+        spin_lock_init(&log->l_write_head.lock);
 
         error = EFSCORRUPTED;
         if (xfs_sb_version_hassector(&mp->m_sb)) {
@@ -1250,7 +1250,7 @@ xlog_grant_push_ail(
 
         ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
 
-        free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
+        free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
         free_blocks = BTOBBT(free_bytes);
 
         /*
@@ -1382,8 +1382,8 @@ xlog_sync(xlog_t		*log,
                  roundoff < BBTOB(1)));
 
         /* move grant heads by roundoff in sync */
-        xlog_grant_add_space(log, &log->l_grant_reserve_head, roundoff);
-        xlog_grant_add_space(log, &log->l_grant_write_head, roundoff);
+        xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
+        xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
 
         /* put cycle number in every block */
         xlog_pack_data(log, iclog, roundoff); 
@@ -2547,8 +2547,8 @@ restart:
  * path. Hence any lock will be globally hot if we take it unconditionally on
  * every pass.
  *
- * As tickets are only ever moved on and off the reserveq under the
- * l_grant_reserve_lock, we only need to take that lock if we are going to add
+ * As tickets are only ever moved on and off the l_reserve.waiters under the
+ * l_reserve.lock, we only need to take that lock if we are going to add
  * the ticket to the queue and sleep. We can avoid taking the lock if the ticket
  * was never added to the reserveq because the t_queue list head will be empty
  * and we hold the only reference to it so it can safely be checked unlocked.
@@ -2574,23 +2574,23 @@ xlog_grant_log_space(
         need_bytes = tic->t_unit_res;
         if (tic->t_flags & XFS_LOG_PERM_RESERV)
                 need_bytes *= tic->t_ocnt;
-        free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
-        if (!list_empty_careful(&log->l_reserveq)) {
-                spin_lock(&log->l_grant_reserve_lock);
+        free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
+        if (!list_empty_careful(&log->l_reserve_head.waiters)) {
+                spin_lock(&log->l_reserve_head.lock);
                 if (!xlog_reserveq_wake(log, &free_bytes) ||
                     free_bytes < need_bytes)
                         error = xlog_reserveq_wait(log, tic, need_bytes);
-                spin_unlock(&log->l_grant_reserve_lock);
+                spin_unlock(&log->l_reserve_head.lock);
         } else if (free_bytes < need_bytes) {
-                spin_lock(&log->l_grant_reserve_lock);
+                spin_lock(&log->l_reserve_head.lock);
                 error = xlog_reserveq_wait(log, tic, need_bytes);
-                spin_unlock(&log->l_grant_reserve_lock);
+                spin_unlock(&log->l_reserve_head.lock);
         }
         if (error)
                 return error;
 
-        xlog_grant_add_space(log, &log->l_grant_reserve_head, need_bytes);
-        xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
+        xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
+        xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
         trace_xfs_log_grant_exit(log, tic);
         xlog_verify_grant_tail(log);
         return 0;
@@ -2627,23 +2627,23 @@ xlog_regrant_write_log_space(
          * otherwise try to get some space for this transaction.
          */
         need_bytes = tic->t_unit_res;
-        free_bytes = xlog_space_left(log, &log->l_grant_write_head);
-        if (!list_empty_careful(&log->l_writeq)) {
-                spin_lock(&log->l_grant_write_lock);
+        free_bytes = xlog_space_left(log, &log->l_write_head.grant);
+        if (!list_empty_careful(&log->l_write_head.waiters)) {
+                spin_lock(&log->l_write_head.lock);
                 if (!xlog_writeq_wake(log, &free_bytes) ||
                     free_bytes < need_bytes)
                         error = xlog_writeq_wait(log, tic, need_bytes);
-                spin_unlock(&log->l_grant_write_lock);
+                spin_unlock(&log->l_write_head.lock);
         } else if (free_bytes < need_bytes) {
-                spin_lock(&log->l_grant_write_lock);
+                spin_lock(&log->l_write_head.lock);
                 error = xlog_writeq_wait(log, tic, need_bytes);
-                spin_unlock(&log->l_grant_write_lock);
+                spin_unlock(&log->l_write_head.lock);
         }
 
         if (error)
                 return error;
 
-        xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
+        xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
         trace_xfs_log_regrant_write_exit(log, tic);
         xlog_verify_grant_tail(log);
         return 0;
@@ -2665,9 +2665,9 @@ xlog_regrant_reserve_log_space(xlog_t	     *log,
         if (ticket->t_cnt > 0)
                 ticket->t_cnt--;
 
-        xlog_grant_sub_space(log, &log->l_grant_reserve_head,
+        xlog_grant_sub_space(log, &log->l_reserve_head.grant,
                                         ticket->t_curr_res);
-        xlog_grant_sub_space(log, &log->l_grant_write_head,
+        xlog_grant_sub_space(log, &log->l_write_head.grant,
                                         ticket->t_curr_res);
         ticket->t_curr_res = ticket->t_unit_res;
         xlog_tic_reset_res(ticket);
@@ -2678,7 +2678,7 @@ xlog_regrant_reserve_log_space(xlog_t	     *log,
         if (ticket->t_cnt > 0)
                 return;
 
-        xlog_grant_add_space(log, &log->l_grant_reserve_head,
+        xlog_grant_add_space(log, &log->l_reserve_head.grant,
                                         ticket->t_unit_res);
 
         trace_xfs_log_regrant_reserve_exit(log, ticket);
@@ -2724,8 +2724,8 @@ xlog_ungrant_log_space(xlog_t	     *log,
                 bytes += ticket->t_unit_res*ticket->t_cnt;
         }
 
-        xlog_grant_sub_space(log, &log->l_grant_reserve_head, bytes);
-        xlog_grant_sub_space(log, &log->l_grant_write_head, bytes);
+        xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
+        xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
 
         trace_xfs_log_ungrant_exit(log, ticket);
 
@@ -3349,7 +3349,7 @@ xlog_verify_grant_tail(
         int             tail_cycle, tail_blocks;
         int             cycle, space;
 
-        xlog_crack_grant_head(&log->l_grant_write_head, &cycle, &space);
+        xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
         if (tail_cycle != cycle) {
                 if (cycle - 1 != tail_cycle &&
@@ -3619,15 +3619,15 @@ xfs_log_force_umount(
          * we don't enqueue anything once the SHUTDOWN flag is set, and this
          * action is protected by the grant locks.
          */
-        spin_lock(&log->l_grant_reserve_lock);
-        list_for_each_entry(tic, &log->l_reserveq, t_queue)
+        spin_lock(&log->l_reserve_head.lock);
+        list_for_each_entry(tic, &log->l_reserve_head.waiters, t_queue)
                 wake_up_process(tic->t_task);
-        spin_unlock(&log->l_grant_reserve_lock);
+        spin_unlock(&log->l_reserve_head.lock);
 
-        spin_lock(&log->l_grant_write_lock);
-        list_for_each_entry(tic, &log->l_writeq, t_queue)
+        spin_lock(&log->l_write_head.lock);
+        list_for_each_entry(tic, &log->l_write_head.waiters, t_queue)
                 wake_up_process(tic->t_task);
-        spin_unlock(&log->l_grant_write_lock);
+        spin_unlock(&log->l_write_head.lock);
 
         if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
                 ASSERT(!logerror);
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index d8c5e47bbc2f..eba4ec925a45 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -470,6 +470,16 @@ struct xfs_cil {
 #define XLOG_CIL_HARD_SPACE_LIMIT(log)  (3 * (log->l_logsize >> 4))
 
 /*
+ * ticket grant locks, queues and accounting have their own cachlines
+ * as these are quite hot and can be operated on concurrently.
+ */
+struct xlog_grant_head {
+        spinlock_t              lock ____cacheline_aligned_in_smp;
+        struct list_head        waiters;
+        atomic64_t              grant;
+};
+
+/*
  * The reservation head lsn is not made up of a cycle number and block number.
  * Instead, it uses a cycle number and byte number.  Logs don't expect to
  * overflow 31 bits worth of byte offset, so using a byte number will mean
@@ -520,17 +530,8 @@ typedef struct log {
         /* lsn of 1st LR with unflushed * buffers */
         atomic64_t              l_tail_lsn ____cacheline_aligned_in_smp;
 
-        /*
-         * ticket grant locks, queues and accounting have their own cachlines
-         * as these are quite hot and can be operated on concurrently.
-         */
-        spinlock_t              l_grant_reserve_lock ____cacheline_aligned_in_smp;
-        struct list_head        l_reserveq;
-        atomic64_t              l_grant_reserve_head;
-
-        spinlock_t              l_grant_write_lock ____cacheline_aligned_in_smp;
-        struct list_head        l_writeq;
-        atomic64_t              l_grant_write_head;
+        struct xlog_grant_head  l_reserve_head;
+        struct xlog_grant_head  l_write_head;
 
         /* The following field are used for debugging; need to hold icloglock */
 #ifdef DEBUG
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 8a3d8aedd1f4..7c75c7374d5a 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -965,9 +965,9 @@ xlog_find_tail(
                 log->l_curr_cycle++;
         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,
+        xlog_assign_grant_head(&log->l_reserve_head.grant, log->l_curr_cycle,
                                         BBTOB(log->l_curr_block));
-        xlog_assign_grant_head(&log->l_grant_write_head, log->l_curr_cycle,
+        xlog_assign_grant_head(&log->l_write_head.grant, log->l_curr_cycle,
                                         BBTOB(log->l_curr_block));
 
         /*
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb134a819930..a80e30854fce 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -782,12 +782,12 @@ DECLARE_EVENT_CLASS(xfs_loggrant_class,
                 __entry->curr_res = tic->t_curr_res;
                 __entry->unit_res = tic->t_unit_res;
                 __entry->flags = tic->t_flags;
-                __entry->reserveq = list_empty(&log->l_reserveq);
-                __entry->writeq = list_empty(&log->l_writeq);
-                xlog_crack_grant_head(&log->l_grant_reserve_head,
+                __entry->reserveq = list_empty(&log->l_reserve_head.waiters);
+                __entry->writeq = list_empty(&log->l_write_head.waiters);
+                xlog_crack_grant_head(&log->l_reserve_head.grant,
                                 &__entry->grant_reserve_cycle,
                                 &__entry->grant_reserve_bytes);
-                xlog_crack_grant_head(&log->l_grant_write_head,
+                xlog_crack_grant_head(&log->l_write_head.grant,
                                 &__entry->grant_write_cycle,
                                 &__entry->grant_write_bytes);
                 __entry->curr_cycle = log->l_curr_cycle;