[XFS] Ensure that 2 GiB xfs logs work properly.

We found this while experimenting with 2GiB xfs logs. The previous code
never assumed that xfs logs would ever get so large.

SGI-PV: 981502
SGI-Modid: xfs-linux-melb:xfs-kern:31058a

Signed-off-by: Michael Nishimoto <miken@agami.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 16a01abe2490..6195cc880101 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -226,20 +226,24 @@ xlog_grant_sub_space(struct log *log, int bytes)
 static void
 xlog_grant_add_space_write(struct log *log, int bytes)
 {
-        log->l_grant_write_bytes += bytes;
-        if (log->l_grant_write_bytes > log->l_logsize) {
-                log->l_grant_write_bytes -= log->l_logsize;
+        int tmp = log->l_logsize - log->l_grant_write_bytes;
+        if (tmp > bytes)
+                log->l_grant_write_bytes += bytes;
+        else {
                 log->l_grant_write_cycle++;
+                log->l_grant_write_bytes = bytes - tmp;
         }
 }
 
 static void
 xlog_grant_add_space_reserve(struct log *log, int bytes)
 {
-        log->l_grant_reserve_bytes += bytes;
-        if (log->l_grant_reserve_bytes > log->l_logsize) {
-                log->l_grant_reserve_bytes -= log->l_logsize;
+        int tmp = log->l_logsize - log->l_grant_reserve_bytes;
+        if (tmp > bytes)
+                log->l_grant_reserve_bytes += bytes;
+        else {
                 log->l_grant_reserve_cycle++;
+                log->l_grant_reserve_bytes = bytes - tmp;
         }
 }