ocfs2: Define the contents of the slot_map file.

The slot map file is merely an array of __le16.  Wrap it in a structure for
cleaner reference.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

2 files changed, 20 insertions, 7 deletions

diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index 3633edd3982f..3299116b8021 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -475,6 +475,18 @@ struct ocfs2_extent_block
 };
 
 /*
+ * On disk slot map for OCFS2.  This defines the contents of the "slot_map"
+ * system file.
+ */
+struct ocfs2_slot_map {
+/*00*/  __le16 sm_slots[0];
+/*
+ * Actual on-disk size is one block.  OCFS2_MAX_SLOTS is 255,
+ * 255 * sizeof(__le16) == 512B, within the 512B block minimum blocksize.
+ */
+};
+
+/*
  * On disk superblock for OCFS2
  * Note that it is contained inside an ocfs2_dinode, so all offsets
  * are relative to the start of ocfs2_dinode.id2.
diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index 65a61bfa3f2e..e7e7a74156b1 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -85,17 +85,17 @@ static void ocfs2_set_slot(struct ocfs2_slot_info *si,
 static void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
 {
         int i;
-        __le16 *disk_info;
+        struct ocfs2_slot_map *sm;
 
         /* we don't read the slot block here as ocfs2_super_lock
          * should've made sure we have the most recent copy. */
-        disk_info = (__le16 *) si->si_bh[0]->b_data;
+        sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
 
         for (i = 0; i < si->si_num_slots; i++) {
-                if (le16_to_cpu(disk_info[i]) == (u16)OCFS2_INVALID_SLOT)
+                if (le16_to_cpu(sm->sm_slots[i]) == (u16)OCFS2_INVALID_SLOT)
                         ocfs2_invalidate_slot(si, i);
                 else
-                        ocfs2_set_slot(si, i, le16_to_cpu(disk_info[i]));
+                        ocfs2_set_slot(si, i, le16_to_cpu(sm->sm_slots[i]));
         }
 }
 
@@ -135,15 +135,16 @@ static int ocfs2_update_disk_slots(struct ocfs2_super *osb,
                                    struct ocfs2_slot_info *si)
 {
         int status, i;
-        __le16 *disk_info = (__le16 *) si->si_bh[0]->b_data;
+        struct ocfs2_slot_map *sm;
 
         spin_lock(&osb->osb_lock);
+        sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
         for (i = 0; i < si->si_num_slots; i++) {
                 if (si->si_slots[i].sl_valid)
-                        disk_info[i] =
+                        sm->sm_slots[i] =
                                 cpu_to_le16(si->si_slots[i].sl_node_num);
                 else
-                        disk_info[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
+                        sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
         }
         spin_unlock(&osb->osb_lock);