btrfs-progs: add table for checksum type and name

Adding this table will make extending btrfs-progs with new checksum types
easier.

Also add accessor functions to access the table fields.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>

cmds/inspect-dump-super.c

@@ -339,12 +339,8 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
 	if (!is_valid_csum_type(csum_type)) {
 		printf("INVALID");
 	} else {
-		if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
-			printf("crc32c");
-			csum_size = btrfs_csum_sizes[csum_type];
-		} else {
-			printf("unknown");
-		}
+		printf("%s", btrfs_super_csum_name(csum_type));
+		csum_size = btrfs_super_csum_size(sb);
 	}
 	printf(")\n");
 	printf("csum_size\t\t%llu\n", (unsigned long long)csum_size);

convert/common.c

@@ -224,7 +224,7 @@ static inline int write_temp_extent_buffer(int fd, struct extent_buffer *buf,
 {
 	int ret;
 
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 
 	/* Temporary extent buffer is always mapped 1:1 on disk */

convert/main.c

@@ -1058,8 +1058,8 @@ static int migrate_super_block(int fd, u64 old_bytenr)
 	BUG_ON(btrfs_super_bytenr(super) != old_bytenr);
 	btrfs_set_super_bytenr(super, BTRFS_SUPER_INFO_OFFSET);
 
-	csum_tree_block_size(buf, btrfs_csum_sizes[BTRFS_CSUM_TYPE_CRC32], 0,
-			     btrfs_super_csum_type(super));
+	csum_tree_block_size(buf, btrfs_super_csum_size(super),
+			     0, btrfs_super_csum_type(super));
 	ret = pwrite(fd, buf->data, BTRFS_SUPER_INFO_SIZE,
 		BTRFS_SUPER_INFO_OFFSET);
 	if (ret != BTRFS_SUPER_INFO_SIZE)

ctree.c

@@ -38,6 +38,35 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct extent_buffer *dst_buf,
 			      struct extent_buffer *src_buf);
 
+static struct btrfs_csum {
+	u16 size;
+	const char *name;
+} btrfs_csums[] = {
+	[BTRFS_CSUM_TYPE_CRC32]		= {  4, "crc32c" },
+};
+
+u16 btrfs_super_csum_size(const struct btrfs_super_block *sb)
+{
+	const u16 csum_type = btrfs_super_csum_type(sb);
+
+	return btrfs_csums[csum_type].size;
+}
+
+const char *btrfs_super_csum_name(u16 csum_type)
+{
+	return btrfs_csums[csum_type].name;
+}
+
+size_t btrfs_super_num_csums(void)
+{
+	return ARRAY_SIZE(btrfs_csums);
+}
+
+u16 btrfs_csum_type_size(u16 csum_type)
+{
+	return btrfs_csums[csum_type].size;
+}
+
 inline void btrfs_init_path(struct btrfs_path *p)
 {
 	memset(p, 0, sizeof(*p));

ctree.h

@@ -169,9 +169,6 @@ enum btrfs_csum_type {
 	BTRFS_CSUM_TYPE_CRC32		= 0,
 };
 
-/* four bytes for CRC32 */
-static int btrfs_csum_sizes[] = { 4 };
-
 #define BTRFS_EMPTY_DIR_SIZE 0
 
 #define BTRFS_FT_UNKNOWN	0
@@ -2263,13 +2260,6 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
 			 uuid_tree_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
 
-static inline int btrfs_super_csum_size(struct btrfs_super_block *s)
-{
-	int t = btrfs_super_csum_type(s);
-	BUG_ON(t >= ARRAY_SIZE(btrfs_csum_sizes));
-	return btrfs_csum_sizes[t];
-}
-
 static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
 {
 	return offsetof(struct btrfs_leaf, items);
@@ -2700,6 +2690,11 @@ void btrfs_set_item_key_unsafe(struct btrfs_root *root,
 			       struct btrfs_path *path,
 			       struct btrfs_key *new_key);
 
+u16 btrfs_super_csum_size(const struct btrfs_super_block *s);
+const char *btrfs_super_csum_name(u16 csum_type);
+u16 btrfs_csum_type_size(u16 csum_type);
+size_t btrfs_super_num_csums(void);
+
 /* root-item.c */
 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *tree_root,

disk-io.c

@@ -1377,11 +1377,11 @@ int btrfs_check_super(struct btrfs_super_block *sb, unsigned sbflags)
 	}
 
 	csum_type = btrfs_super_csum_type(sb);
-	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
+	if (csum_type >= btrfs_super_num_csums()) {
 		error("unsupported checksum algorithm %u", csum_type);
 		return -EIO;
 	}
-	csum_size = btrfs_csum_sizes[csum_type];
+	csum_size = btrfs_super_csum_size(sb);
 
 	btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE,
 			result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);

image/main.c

@@ -121,11 +121,12 @@ static struct extent_buffer *alloc_dummy_eb(u64 bytenr, u32 size);
 
 static void csum_block(u8 *buf, size_t len)
 {
-	u8 result[btrfs_csum_sizes[BTRFS_CSUM_TYPE_CRC32]];
+	u16 csum_size = btrfs_csum_type_size(BTRFS_CSUM_TYPE_CRC32);
+	u8 result[csum_size];
 	u32 crc = ~(u32)0;
 	crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len - BTRFS_CSUM_SIZE);
 	put_unaligned_le32(~crc, result);
-	memcpy(buf, result, btrfs_csum_sizes[BTRFS_CSUM_TYPE_CRC32]);
+	memcpy(buf, result, csum_size);
 }
 
 static int has_name(struct btrfs_key *key)

mkfs/common.c

@@ -101,7 +101,7 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 	}
 
 	/* generate checksum */
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 
 	/* write back root tree */
@@ -293,7 +293,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_EXTENT_TREE]);
 	btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
 	btrfs_set_header_nritems(buf, nritems);
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_EXTENT_TREE]);
 	if (ret != cfg->nodesize) {
@@ -382,7 +382,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_CHUNK_TREE]);
 	btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
 	btrfs_set_header_nritems(buf, nritems);
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_CHUNK_TREE]);
 	if (ret != cfg->nodesize) {
@@ -423,7 +423,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_DEV_TREE]);
 	btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
 	btrfs_set_header_nritems(buf, nritems);
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_DEV_TREE]);
 	if (ret != cfg->nodesize) {
@@ -437,7 +437,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_FS_TREE]);
 	btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
 	btrfs_set_header_nritems(buf, 0);
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_FS_TREE]);
 	if (ret != cfg->nodesize) {
@@ -450,7 +450,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_CSUM_TREE]);
 	btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
 	btrfs_set_header_nritems(buf, 0);
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_CSUM_TREE]);
 	if (ret != cfg->nodesize) {
@@ -462,7 +462,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
 	memcpy(buf->data, &super, sizeof(super));
 	buf->len = BTRFS_SUPER_INFO_SIZE;
-	csum_tree_block_size(buf, btrfs_csum_sizes[cfg->csum_type], 0,
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
 	ret = pwrite(fd, buf->data, BTRFS_SUPER_INFO_SIZE,
 			cfg->blocks[MKFS_SUPER_BLOCK]);