ocfs2: Avoid unnecessary block mapping when refreshing quota info

The position of global quota file info does not change. So we do not have
to do logical -> physical block translation every time we reread it from
disk. Thus we can also avoid taking ip_alloc_sem.

Acked-by: Joel Becker <Joel.Becker@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index f461f9678f9f..f391b11ea98c 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -325,6 +325,7 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
         struct ocfs2_global_disk_dqinfo dinfo;
         struct mem_dqinfo *info = sb_dqinfo(sb, type);
         struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
+        u64 pcount;
         int status;
 
         mlog_entry_void();
@@ -351,9 +352,19 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
                 mlog_errno(status);
                 goto out_err;
         }
+
+        status = ocfs2_extent_map_get_blocks(gqinode, 0, &oinfo->dqi_giblk,
+                                             &pcount, NULL);
+        if (status < 0)
+                goto out_unlock;
+
+        status = ocfs2_qinfo_lock(oinfo, 0);
+        if (status < 0)
+                goto out_unlock;
         status = sb->s_op->quota_read(sb, type, (char *)&dinfo,
                                       sizeof(struct ocfs2_global_disk_dqinfo),
                                       OCFS2_GLOBAL_INFO_OFF);
+        ocfs2_qinfo_unlock(oinfo, 0);
         ocfs2_unlock_global_qf(oinfo, 0);
         if (status != sizeof(struct ocfs2_global_disk_dqinfo)) {
                 mlog(ML_ERROR, "Cannot read global quota info (%d).\n",
@@ -380,6 +391,10 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
 out_err:
         mlog_exit(status);
         return status;
+out_unlock:
+        ocfs2_unlock_global_qf(oinfo, 0);
+        mlog_errno(status);
+        goto out_err;
 }
 
 /* Write information to global quota file. Expects exlusive lock on quota