ocfs2: add extent block stealing for ocfs2 v5

This patch add extent block (metadata) stealing mechanism for
extent allocation. This mechanism is same as the inode stealing.
if no room in slot specific extent_alloc, we will try to
allocate extent block from the next slot.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Acked-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 131 insertions, 40 deletions

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index c30b644d957..c3c60bc3e07 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -51,7 +51,7 @@
 #define ALLOC_NEW_GROUP			0x1
 #define ALLOC_GROUPS_FROM_GLOBAL	0x2
 
-#define OCFS2_MAX_INODES_TO_STEAL	1024
+#define OCFS2_MAX_TO_STEAL		1024
 
 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
@@ -637,12 +637,113 @@ bail:
 	return status;
 }
 
+static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
+{
+	spin_lock(&osb->osb_lock);
+	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
+	spin_unlock(&osb->osb_lock);
+	atomic_set(&osb->s_num_inodes_stolen, 0);
+}
+
+static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
+{
+	spin_lock(&osb->osb_lock);
+	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
+	spin_unlock(&osb->osb_lock);
+	atomic_set(&osb->s_num_meta_stolen, 0);
+}
+
+void ocfs2_init_steal_slots(struct ocfs2_super *osb)
+{
+	ocfs2_init_inode_steal_slot(osb);
+	ocfs2_init_meta_steal_slot(osb);
+}
+
+static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
+{
+	spin_lock(&osb->osb_lock);
+	if (type == INODE_ALLOC_SYSTEM_INODE)
+		osb->s_inode_steal_slot = slot;
+	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
+		osb->s_meta_steal_slot = slot;
+	spin_unlock(&osb->osb_lock);
+}
+
+static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
+{
+	int slot = OCFS2_INVALID_SLOT;
+
+	spin_lock(&osb->osb_lock);
+	if (type == INODE_ALLOC_SYSTEM_INODE)
+		slot = osb->s_inode_steal_slot;
+	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
+		slot = osb->s_meta_steal_slot;
+	spin_unlock(&osb->osb_lock);
+
+	return slot;
+}
+
+static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
+{
+	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
+}
+
+static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
+{
+	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
+}
+
+static int ocfs2_steal_resource(struct ocfs2_super *osb,
+				struct ocfs2_alloc_context *ac,
+				int type)
+{
+	int i, status = -ENOSPC;
+	int slot = __ocfs2_get_steal_slot(osb, type);
+
+	/* Start to steal resource from the first slot after ours. */
+	if (slot == OCFS2_INVALID_SLOT)
+		slot = osb->slot_num + 1;
+
+	for (i = 0; i < osb->max_slots; i++, slot++) {
+		if (slot == osb->max_slots)
+			slot = 0;
+
+		if (slot == osb->slot_num)
+			continue;
+
+		status = ocfs2_reserve_suballoc_bits(osb, ac,
+						     type,
+						     (u32)slot, NULL,
+						     NOT_ALLOC_NEW_GROUP);
+		if (status >= 0) {
+			__ocfs2_set_steal_slot(osb, slot, type);
+			break;
+		}
+
+		ocfs2_free_ac_resource(ac);
+	}
+
+	return status;
+}
+
+static int ocfs2_steal_inode(struct ocfs2_super *osb,
+			     struct ocfs2_alloc_context *ac)
+{
+	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
+}
+
+static int ocfs2_steal_meta(struct ocfs2_super *osb,
+			    struct ocfs2_alloc_context *ac)
+{
+	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
+}
+
 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 				      int blocks,
 				      struct ocfs2_alloc_context **ac)
 {
 	int status;
-	u32 slot;
+	int slot = ocfs2_get_meta_steal_slot(osb);
 
 	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 	if (!(*ac)) {
@@ -653,12 +754,34 @@ int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 
 	(*ac)->ac_bits_wanted = blocks;
 	(*ac)->ac_which = OCFS2_AC_USE_META;
-	slot = osb->slot_num;
 	(*ac)->ac_group_search = ocfs2_block_group_search;
 
+	if (slot != OCFS2_INVALID_SLOT &&
+		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
+		goto extent_steal;
+
+	atomic_set(&osb->s_num_meta_stolen, 0);
 	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 					     EXTENT_ALLOC_SYSTEM_INODE,
-					     slot, NULL, ALLOC_NEW_GROUP);
+					     (u32)osb->slot_num, NULL,
+					     ALLOC_NEW_GROUP);
+
+
+	if (status >= 0) {
+		status = 0;
+		if (slot != OCFS2_INVALID_SLOT)
+			ocfs2_init_meta_steal_slot(osb);
+		goto bail;
+	} else if (status < 0 && status != -ENOSPC) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+	ocfs2_free_ac_resource(*ac);
+
+extent_steal:
+	status = ocfs2_steal_meta(osb, *ac);
+	atomic_inc(&osb->s_num_meta_stolen);
 	if (status < 0) {
 		if (status != -ENOSPC)
 			mlog_errno(status);
@@ -685,43 +808,11 @@ int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 					ac);
 }
 
-static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
-					      struct ocfs2_alloc_context *ac)
-{
-	int i, status = -ENOSPC;
-	s16 slot = ocfs2_get_inode_steal_slot(osb);
-
-	/* Start to steal inodes from the first slot after ours. */
-	if (slot == OCFS2_INVALID_SLOT)
-		slot = osb->slot_num + 1;
-
-	for (i = 0; i < osb->max_slots; i++, slot++) {
-		if (slot == osb->max_slots)
-			slot = 0;
-
-		if (slot == osb->slot_num)
-			continue;
-
-		status = ocfs2_reserve_suballoc_bits(osb, ac,
-						     INODE_ALLOC_SYSTEM_INODE,
-						     slot, NULL,
-						     NOT_ALLOC_NEW_GROUP);
-		if (status >= 0) {
-			ocfs2_set_inode_steal_slot(osb, slot);
-			break;
-		}
-
-		ocfs2_free_ac_resource(ac);
-	}
-
-	return status;
-}
-
 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 			    struct ocfs2_alloc_context **ac)
 {
 	int status;
-	s16 slot = ocfs2_get_inode_steal_slot(osb);
+	int slot = ocfs2_get_inode_steal_slot(osb);
 	u64 alloc_group;
 
 	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
@@ -754,14 +845,14 @@ int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 	 * need to check our slots to see whether there is some space for us.
 	 */
 	if (slot != OCFS2_INVALID_SLOT &&
-	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
+	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
 		goto inode_steal;
 
 	atomic_set(&osb->s_num_inodes_stolen, 0);
 	alloc_group = osb->osb_inode_alloc_group;
 	status = ocfs2_reserve_suballoc_bits(osb, *ac,
 					     INODE_ALLOC_SYSTEM_INODE,
-					     osb->slot_num,
+					     (u32)osb->slot_num,
 					     &alloc_group,
 					     ALLOC_NEW_GROUP |
 					     ALLOC_GROUPS_FROM_GLOBAL);
@@ -789,7 +880,7 @@ int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 	ocfs2_free_ac_resource(*ac);
 
 inode_steal:
-	status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
+	status = ocfs2_steal_inode(osb, *ac);
 	atomic_inc(&osb->s_num_inodes_stolen);
 	if (status < 0) {
 		if (status != -ENOSPC)