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>
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index d17bdc7..2bbe1ecc 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -1050,7 +1050,8 @@
 			strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
 			eb->h_blkno = cpu_to_le64(first_blkno);
 			eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
-			eb->h_suballoc_slot = cpu_to_le16(osb->slot_num);
+			eb->h_suballoc_slot =
+				cpu_to_le16(meta_ac->ac_alloc_slot);
 			eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 			eb->h_list.l_count =
 				cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
@@ -6037,7 +6038,7 @@
 	if (status < 0)
 		mlog_errno(status);
 	else
-		ocfs2_init_inode_steal_slot(osb);
+		ocfs2_init_steal_slots(osb);
 
 	mlog_exit(status);
 }
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 28c3ec2..765d66c 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -2439,7 +2439,7 @@
 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
 	memset(dx_root, 0, osb->sb->s_blocksize);
 	strcpy(dx_root->dr_signature, OCFS2_DX_ROOT_SIGNATURE);
-	dx_root->dr_suballoc_slot = cpu_to_le16(osb->slot_num);
+	dx_root->dr_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 	dx_root->dr_suballoc_bit = cpu_to_le16(dr_suballoc_bit);
 	dx_root->dr_fs_generation = cpu_to_le32(osb->fs_generation);
 	dx_root->dr_blkno = cpu_to_le64(dr_blkno);
diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index ac10f83..ca992d9 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -476,7 +476,7 @@
 
 out:
 	if (!status)
-		ocfs2_init_inode_steal_slot(osb);
+		ocfs2_init_steal_slots(osb);
 	mlog_exit(status);
 	return status;
 }
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 740f448..8857dd7 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -305,7 +305,9 @@
 	u32 s_next_generation;
 	unsigned long osb_flags;
 	s16 s_inode_steal_slot;
+	s16 s_meta_steal_slot;
 	atomic_t s_num_inodes_stolen;
+	atomic_t s_num_meta_stolen;
 
 	unsigned long s_mount_opt;
 	unsigned int s_atime_quantum;
@@ -760,33 +762,6 @@
 	return megs << (20 - OCFS2_SB(sb)->s_clustersize_bits);
 }
 
-static inline 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 inline void ocfs2_set_inode_steal_slot(struct ocfs2_super *osb,
-					      s16 slot)
-{
-	spin_lock(&osb->osb_lock);
-	osb->s_inode_steal_slot = slot;
-	spin_unlock(&osb->osb_lock);
-}
-
-static inline s16 ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
-{
-	s16 slot;
-
-	spin_lock(&osb->osb_lock);
-	slot = osb->s_inode_steal_slot;
-	spin_unlock(&osb->osb_lock);
-
-	return slot;
-}
-
 #define ocfs2_set_bit ext2_set_bit
 #define ocfs2_clear_bit ext2_clear_bit
 #define ocfs2_test_bit ext2_test_bit
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 8ae65c9..fb6aa7a 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -626,7 +626,7 @@
 	rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 	memset(rb, 0, inode->i_sb->s_blocksize);
 	strcpy((void *)rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
-	rb->rf_suballoc_slot = cpu_to_le16(osb->slot_num);
+	rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 	rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 	rb->rf_fs_generation = cpu_to_le32(osb->fs_generation);
 	rb->rf_blkno = cpu_to_le64(first_blkno);
@@ -1330,7 +1330,7 @@
 	memcpy(new_bh->b_data, ref_root_bh->b_data, sb->s_blocksize);
 
 	new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
-	new_rb->rf_suballoc_slot = cpu_to_le16(OCFS2_SB(sb)->slot_num);
+	new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 	new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 	new_rb->rf_blkno = cpu_to_le64(blkno);
 	new_rb->rf_cpos = cpu_to_le32(0);
@@ -1576,7 +1576,7 @@
 	new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 	memset(new_rb, 0, sb->s_blocksize);
 	strcpy((void *)new_rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
-	new_rb->rf_suballoc_slot = cpu_to_le16(OCFS2_SB(sb)->slot_num);
+	new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 	new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 	new_rb->rf_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 	new_rb->rf_blkno = cpu_to_le64(blkno);
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index c30b644..c3c60bc 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 @@
 	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 @@
 
 	(*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 @@
 					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 @@
 	 * 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 @@
 	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)
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index 8c9a78a..fa60723 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -56,6 +56,7 @@
 				 is the same as ~0 - unlimited */
 };
 
+void ocfs2_init_steal_slots(struct ocfs2_super *osb);
 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
 {
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 755cd49..dee0319 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -69,6 +69,7 @@
 #include "xattr.h"
 #include "quota.h"
 #include "refcounttree.h"
+#include "suballoc.h"
 
 #include "buffer_head_io.h"
 
@@ -301,9 +302,12 @@
 
 	spin_lock(&osb->osb_lock);
 	out += snprintf(buf + out, len - out,
-			"%10s => Slot: %d  NumStolen: %d\n", "Steal",
+			"%10s => InodeSlot: %d  StolenInodes: %d, "
+			"MetaSlot: %d  StolenMeta: %d\n", "Steal",
 			osb->s_inode_steal_slot,
-			atomic_read(&osb->s_num_inodes_stolen));
+			atomic_read(&osb->s_num_inodes_stolen),
+			osb->s_meta_steal_slot,
+			atomic_read(&osb->s_num_meta_stolen));
 	spin_unlock(&osb->osb_lock);
 
 	out += snprintf(buf + out, len - out, "OrphanScan => ");
@@ -1997,7 +2001,7 @@
 	osb->blocked_lock_count = 0;
 	spin_lock_init(&osb->osb_lock);
 	spin_lock_init(&osb->osb_xattr_lock);
-	ocfs2_init_inode_steal_slot(osb);
+	ocfs2_init_steal_slots(osb);
 
 	atomic_set(&osb->alloc_stats.moves, 0);
 	atomic_set(&osb->alloc_stats.local_data, 0);
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 8fc6fb0..8ae4e5d1 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -2282,7 +2282,7 @@
 	xblk = (struct ocfs2_xattr_block *)new_bh->b_data;
 	memset(xblk, 0, inode->i_sb->s_blocksize);
 	strcpy((void *)xblk, OCFS2_XATTR_BLOCK_SIGNATURE);
-	xblk->xb_suballoc_slot = cpu_to_le16(osb->slot_num);
+	xblk->xb_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 	xblk->xb_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 	xblk->xb_fs_generation = cpu_to_le32(osb->fs_generation);
 	xblk->xb_blkno = cpu_to_le64(first_blkno);