Btrfs: add a new "type" field into the block reservation structure

Sometimes we need choose the method of the reservation according to the type
of the block reservation, such as the reservation for the delayed inode update.
Now we identify the type just by comparing the address of the reservation
variants, it is very ugly if it is a temporary one because we need compare it
with all the common reservation variants. So we add a new "type" field to keep
the type the reservation variants.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

fs/btrfs/ctree.h

@@ -1028,13 +1028,22 @@ struct btrfs_space_info {
 	wait_queue_head_t wait;
 };
 
+#define	BTRFS_BLOCK_RSV_GLOBAL		1
+#define	BTRFS_BLOCK_RSV_DELALLOC	2
+#define	BTRFS_BLOCK_RSV_TRANS		3
+#define	BTRFS_BLOCK_RSV_CHUNK		4
+#define	BTRFS_BLOCK_RSV_DELOPS		5
+#define	BTRFS_BLOCK_RSV_EMPTY		6
+#define	BTRFS_BLOCK_RSV_TEMP		7
+
 struct btrfs_block_rsv {
 	u64 size;
 	u64 reserved;
 	struct btrfs_space_info *space_info;
 	spinlock_t lock;
-	unsigned int full;
-	unsigned int failfast;
+	unsigned short full;
+	unsigned short type;
+	unsigned short failfast;
 };
 
 /*
@@ -2875,8 +2884,9 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes);
 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes);
 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes);
 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes);
-void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv);
-struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root);
+void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type);
+struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
+					      unsigned short type);
 void btrfs_free_block_rsv(struct btrfs_root *root,
 			  struct btrfs_block_rsv *rsv);
 int btrfs_block_rsv_add(struct btrfs_root *root,

fs/btrfs/delayed-inode.c

@@ -650,7 +650,7 @@ static int btrfs_delayed_inode_reserve_metadata(
 	 * we're accounted for.
 	 */
 	if (!src_rsv || (!trans->bytes_reserved &&
-	    src_rsv != &root->fs_info->delalloc_block_rsv)) {
+			 src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 		ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
 		/*
 		 * Since we're under a transaction reserve_metadata_bytes could
@@ -668,7 +668,7 @@ static int btrfs_delayed_inode_reserve_metadata(
 						      num_bytes, 1);
 		}
 		return ret;
-	} else if (src_rsv == &root->fs_info->delalloc_block_rsv) {
+	} else if (src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
 		spin_lock(&BTRFS_I(inode)->lock);
 		if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
 				       &BTRFS_I(inode)->runtime_flags)) {

fs/btrfs/disk-io.c

@@ -2014,12 +2014,15 @@ int open_ctree(struct super_block *sb,
 	INIT_LIST_HEAD(&fs_info->space_info);
 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
 	btrfs_mapping_init(&fs_info->mapping_tree);
-	btrfs_init_block_rsv(&fs_info->global_block_rsv);
-	btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
-	btrfs_init_block_rsv(&fs_info->trans_block_rsv);
-	btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
-	btrfs_init_block_rsv(&fs_info->empty_block_rsv);
-	btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
+	btrfs_init_block_rsv(&fs_info->global_block_rsv,
+			     BTRFS_BLOCK_RSV_GLOBAL);
+	btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
+			     BTRFS_BLOCK_RSV_DELALLOC);
+	btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
+	btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
+	btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
+	btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
+			     BTRFS_BLOCK_RSV_DELOPS);
 	atomic_set(&fs_info->nr_async_submits, 0);
 	atomic_set(&fs_info->async_delalloc_pages, 0);
 	atomic_set(&fs_info->async_submit_draining, 0);

fs/btrfs/extent-tree.c

@@ -4108,13 +4108,15 @@ static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
 	return 0;
 }
 
-void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
+void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
 {
 	memset(rsv, 0, sizeof(*rsv));
 	spin_lock_init(&rsv->lock);
+	rsv->type = type;
 }
 
-struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
+struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
+					      unsigned short type)
 {
 	struct btrfs_block_rsv *block_rsv;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -4123,7 +4125,7 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
 	if (!block_rsv)
 		return NULL;
 
-	btrfs_init_block_rsv(block_rsv);
+	btrfs_init_block_rsv(block_rsv, type);
 	block_rsv->space_info = __find_space_info(fs_info,
 						  BTRFS_BLOCK_GROUP_METADATA);
 	return block_rsv;

fs/btrfs/file.c

@@ -1874,7 +1874,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 		goto out;
 	}
 
-	rsv = btrfs_alloc_block_rsv(root);
+	rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
 	if (!rsv) {
 		ret = -ENOMEM;
 		goto out_free;

fs/btrfs/inode.c

@@ -2195,7 +2195,7 @@ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
 	int ret;
 
 	if (!root->orphan_block_rsv) {
-		block_rsv = btrfs_alloc_block_rsv(root);
+		block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
 		if (!block_rsv)
 			return -ENOMEM;
 	}
@@ -3070,7 +3070,7 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root)
 {
-	if (trans->block_rsv == &root->fs_info->global_block_rsv) {
+	if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
 		btrfs_block_rsv_release(root, trans->block_rsv,
 					trans->bytes_reserved);
 		trans->block_rsv = &root->fs_info->trans_block_rsv;
@@ -3821,7 +3821,7 @@ void btrfs_evict_inode(struct inode *inode)
 		goto no_delete;
 	}
 
-	rsv = btrfs_alloc_block_rsv(root);
+	rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
 	if (!rsv) {
 		btrfs_orphan_del(NULL, inode);
 		goto no_delete;
@@ -6851,7 +6851,7 @@ static int btrfs_truncate(struct inode *inode)
 	 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
 	 * updating the inode.
 	 */
-	rsv = btrfs_alloc_block_rsv(root);
+	rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
 	if (!rsv)
 		return -ENOMEM;
 	rsv->size = min_size;

fs/btrfs/ioctl.c

@@ -516,7 +516,8 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 	if (!pending_snapshot)
 		return -ENOMEM;
 
-	btrfs_init_block_rsv(&pending_snapshot->block_rsv);
+	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
+			     BTRFS_BLOCK_RSV_TEMP);
 	pending_snapshot->dentry = dentry;
 	pending_snapshot->root = root;
 	pending_snapshot->readonly = readonly;

fs/btrfs/relocation.c

@@ -3674,7 +3674,8 @@ int prepare_to_relocate(struct reloc_control *rc)
 	struct btrfs_trans_handle *trans;
 	int ret;
 
-	rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
+	rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
+					      BTRFS_BLOCK_RSV_TEMP);
 	if (!rc->block_rsv)
 		return -ENOMEM;