1 files changed, 25 insertions, 31 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 70790eb48336..d118bf804480 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));
         }
 }