xfs: Refactor xfs_ticket_alloc() to extract a new helper

Refactor xlog_ticket_alloc() to extract a new helper, i.e.
xfs_log_calc_unit_res().

This helper would be used to calculate the total log reservation
size by adding extra log operation/transation headers for a new
log ticket.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 38 insertions, 22 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index bf89eb97fefd..704f0959e9c6 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3391,24 +3391,17 @@ xfs_log_ticket_get(
 }
 
 /*
- * Allocate and initialise a new log ticket.
+ * Figure out the total log space unit (in bytes) that would be
+ * required for a log ticket.
  */
-struct xlog_ticket *
-xlog_ticket_alloc(
-        struct xlog     *log,
-        int             unit_bytes,
-        int             cnt,
-        char            client,
-        bool            permanent,
-        xfs_km_flags_t  alloc_flags)
+int
+xfs_log_calc_unit_res(
+        struct xfs_mount        *mp,
+        int                     unit_bytes)
 {
-        struct xlog_ticket *tic;
-        uint            num_headers;
-        int             iclog_space;
-
-        tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
-        if (!tic)
-                return NULL;
+        struct xlog             *log = mp->m_log;
+        int                     iclog_space;
+        uint                    num_headers;
 
         /*
          * Permanent reservations have up to 'cnt'-1 active log operations
@@ -3483,20 +3476,43 @@ xlog_ticket_alloc(
         unit_bytes += log->l_iclog_hsize;
 
         /* for roundoff padding for transaction data and one for commit record */
-        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
-            log->l_mp->m_sb.sb_logsunit > 1) {
+        if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
                 /* log su roundoff */
-                unit_bytes += 2*log->l_mp->m_sb.sb_logsunit;
+                unit_bytes += 2 * mp->m_sb.sb_logsunit;
         } else {
                 /* BB roundoff */
-                unit_bytes += 2*BBSIZE;
+                unit_bytes += 2 * BBSIZE;
         }
 
+        return unit_bytes;
+}
+
+/*
+ * Allocate and initialise a new log ticket.
+ */
+struct xlog_ticket *
+xlog_ticket_alloc(
+        struct xlog             *log,
+        int                     unit_bytes,
+        int                     cnt,
+        char                    client,
+        bool                    permanent,
+        xfs_km_flags_t          alloc_flags)
+{
+        struct xlog_ticket      *tic;
+        int                     unit_res;
+
+        tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
+        if (!tic)
+                return NULL;
+
+        unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
+
         atomic_set(&tic->t_ref, 1);
         tic->t_task             = current;
         INIT_LIST_HEAD(&tic->t_queue);
-        tic->t_unit_res         = unit_bytes;
-        tic->t_curr_res         = unit_bytes;
+        tic->t_unit_res         = unit_res;
+        tic->t_curr_res         = unit_res;
         tic->t_cnt              = cnt;
         tic->t_ocnt             = cnt;
         tic->t_tid              = prandom_u32();