add support for multiple csum algorithms

index b5af1fc..770b720 100644
@@ -109,8 +109,12 @@ struct btrfs_ordered_sum;
 
 /* 32 bytes in various csum fields */
 #define BTRFS_CSUM_SIZE 32
+
+/* csum types */
+#define BTRFS_CSUM_TYPE_CRC32	0
+
 /* four bytes for CRC32 */
-#define BTRFS_CRC32_SIZE 4
+//#define BTRFS_CRC32_SIZE 4
 #define BTRFS_EMPTY_DIR_SIZE 0
 
 #define BTRFS_FT_UNKNOWN	0

@@ -308,6 +312,8 @@ struct btrfs_super_block {
 	__le64 compat_flags;
 	__le64 compat_ro_flags;
 	__le64 incompat_flags;
+	__le16 csum_type;
+	__le16 csum_sectorsize;
 	u8 root_level;
 	u8 chunk_root_level;
 	u8 log_root_level;

@@ -1524,6 +1530,10 @@ BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,
 			 compat_flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,
 			 incompat_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct btrfs_super_block,
+			 csum_type, 16);
+BTRFS_SETGET_STACK_FUNCS(super_csum_sectorsize, struct btrfs_super_block,
+			 csum_sectorsize, 16);
 
 static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
 {

index 6047858..1ad9d66 100644
@@ -175,7 +175,9 @@ void btrfs_csum_final(u32 crc, char *result)
 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 			   int verify)
 {
-	char result[BTRFS_CRC32_SIZE];
+	u16 csum_sectorsize =
+		btrfs_super_csum_sectorsize(&root->fs_info->super_copy);
+	char *result;
 	unsigned long len;
 	unsigned long cur_len;
 	unsigned long offset = BTRFS_CSUM_SIZE;

@@ -203,25 +205,31 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 		offset += cur_len;
 		unmap_extent_buffer(buf, map_token, KM_USER0);
 	}
+	result = kzalloc(csum_sectorsize * sizeof(char), GFP_NOFS);
+	if (!result)
+		return 1;
+
 	btrfs_csum_final(crc, result);
 
 	if (verify) {
 		/* FIXME, this is not good */
-		if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
+		if (memcmp_extent_buffer(buf, result, 0, csum_sectorsize)) {
 			u32 val;
 			u32 found = 0;
-			memcpy(&found, result, BTRFS_CRC32_SIZE);
+			memcpy(&found, result, csum_sectorsize);
 
-			read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
+			read_extent_buffer(buf, &val, 0, csum_sectorsize);
 			printk("btrfs: %s checksum verify failed on %llu "
 			       "wanted %X found %X level %d\n",
 			       root->fs_info->sb->s_id,
 			       buf->start, val, found, btrfs_header_level(buf));
+			kfree(result);
 			return 1;
 		}
 	} else {
-		write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
+		write_extent_buffer(buf, result, 0, csum_sectorsize);
 	}
+	kfree(result);
 	return 0;
 }
 

174 lines not on this page · raw message

index 8828109..2c8f18a 100644
@@ -713,7 +713,8 @@ long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, u64 off,
 	u64 len = olen;
 	u64 bs = root->fs_info->sb->s_blocksize;
 	u64 hint_byte;
-
+	u16 csum_sectorsize =
+		btrfs_super_csum_sectorsize(&root->fs_info->super_copy);
 	/*
 	 * TODO:
 	 * - split compressed inline extents.  annoying: we need to

@@ -963,7 +964,7 @@ long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, u64 off,
 			int coff, clen;
 
 			size = btrfs_item_size_nr(leaf, slot);
-			coverslen = (size / BTRFS_CRC32_SIZE) <<
+			coverslen = (size / csum_sectorsize) <<
 				root->fs_info->sb->s_blocksize_bits;
 			printk("csums for %llu~%llu\n",
 			       key.offset, coverslen);

@@ -980,12 +981,12 @@ long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, u64 off,
 			if (off > key.offset)
 				coff = ((off - key.offset) >>
 					root->fs_info->sb->s_blocksize_bits) *
-					BTRFS_CRC32_SIZE;
+					csum_sectorsize;
 			clen = size - coff;
 			if (key.offset + coverslen > off+len)
 				clen -= ((key.offset+coverslen-off-len) >>
 					 root->fs_info->sb->s_blocksize_bits) *
-					BTRFS_CRC32_SIZE;
+					csum_sectorsize;
 			printk(" will dup %d~%d of %d\n",
 			       coff, clen, size);
 

index be4fc30..478b4dc 100644
@@ -928,13 +928,15 @@ static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
 	int ret;
 	u32 item_size = btrfs_item_size_nr(eb, slot);
 	u64 cur_offset;
+	u16 csum_sectorsize =
+		btrfs_super_csum_sectorsize(&root->fs_info->super_copy);
 	unsigned long file_bytes;
 	struct btrfs_ordered_sum *sums;
 	struct btrfs_sector_sum *sector_sum;
 	struct inode *inode;
 	unsigned long ptr;
 
-	file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
+	file_bytes = (item_size / csum_sectorsize) * root->sectorsize;
 	inode = read_one_inode(root, key->objectid);
 	if (!inode) {
 		return -EIO;

@@ -958,10 +960,10 @@ static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
 	ptr = btrfs_item_ptr_offset(eb, slot);
 	while(item_size > 0) {
 		sector_sum->offset = cur_offset;
-		read_extent_buffer(eb, &sector_sum->sum, ptr, BTRFS_CRC32_SIZE);
+		read_extent_buffer(eb, &sector_sum->sum, ptr, csum_sectorsize);
 		sector_sum++;
-		item_size -= BTRFS_CRC32_SIZE;
-		ptr += BTRFS_CRC32_SIZE;
+		item_size -= csum_sectorsize;
+		ptr += csum_sectorsize;
 		cur_offset += root->sectorsize;
 	}