ocfs2: Add "preferred slot" mount option
ocfs2 will attempt to assign the node the slot# provided in the mount
option. Failure to assign the preferred slot is not an error. This small
feature can be useful for automated testing.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index d8b7906..af4882b 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -121,17 +121,25 @@
return ret;
}
-static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si)
+static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si, s16 preferred)
{
int i;
s16 ret = OCFS2_INVALID_SLOT;
+ if (preferred >= 0 && preferred < si->si_num_slots) {
+ if (OCFS2_INVALID_SLOT == si->si_global_node_nums[preferred]) {
+ ret = preferred;
+ goto out;
+ }
+ }
+
for(i = 0; i < si->si_num_slots; i++) {
if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
ret = (s16) i;
break;
}
}
+out:
return ret;
}
@@ -248,7 +256,7 @@
if (slot == OCFS2_INVALID_SLOT) {
/* if no slot yet, then just take 1st available
* one. */
- slot = __ocfs2_find_empty_slot(si);
+ slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
if (slot == OCFS2_INVALID_SLOT) {
spin_unlock(&si->si_lock);
mlog(ML_ERROR, "no free slots available!\n");