path: root/include/linux/raid
diff options
authorNeilBrown <neilb@suse.de>2006-03-27 01:18:07 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-27 08:45:01 -0800
commitad01c9e3752f4ba4f3d99c89b7370fa4983a25b5 (patch)
tree856868aa97332d6d15d4cad412e0ebe3576bb571 /include/linux/raid
parent[PATCH] md: Split disks array out of raid5 conf structure so it is easier to grow (diff)
[PATCH] md: Allow stripes to be expanded in preparation for expanding an array
Before a RAID-5 can be expanded, we need to be able to expand the stripe-cache data structure. This requires allocating new stripes in a new kmem_cache. If this succeeds, we copy cache pages over and release the old stripes and kmem_cache. We then allocate new pages. If that fails, we leave the stripe cache at it's new size. It isn't worth the effort to shrink it back again. Unfortuanately this means we need two kmem_cache names as we, for a short period of time, we have two kmem_caches. So they are raid5/%s and raid5/%s-alt Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/raid')
1 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 94dbdd406f12..b7b2653af7bb 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -216,7 +216,11 @@ struct raid5_private_data {
struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */
atomic_t preread_active_stripes; /* stripes with scheduled io */
- char cache_name[20];
+ /* unfortunately we need two cache names as we temporarily have
+ * two caches.
+ */
+ int active_name;
+ char cache_name[2][20];
kmem_cache_t *slab_cache; /* for allocating stripes */
int seq_flush, seq_write;
@@ -238,7 +242,8 @@ struct raid5_private_data {
wait_queue_head_t wait_for_overlap;
int inactive_blocked; /* release of inactive stripes blocked,
* waiting for 25% to be free
- */
+ */
+ int pool_size; /* number of disks in stripeheads in pool */
spinlock_t device_lock;
struct disk_info *disks;