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Commit b6cda9bc authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Add mount -o nodatasum to turn of file data checksumming 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent e9906a98

fs/btrfs/ctree.h

+8 −6
Original line number Diff line number Diff line
@@ -321,6 +321,7 @@ struct btrfs_fs_info { 


	u64 generation;

	u64 last_trans_committed;

	unsigned long mount_opt;

	struct btrfs_transaction *running_transaction;

	struct btrfs_super_block super_copy;

	struct extent_buffer *sb_buffer;
@@ -429,6 +430,13 @@ struct btrfs_root { 
 */

#define BTRFS_STRING_ITEM_KEY	253



#define BTRFS_MOUNT_NODATASUM		0x1



#define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)

#define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)

#define btrfs_test_opt(root, opt)	((root)->fs_info->mount_opt & \

					 BTRFS_MOUNT_##opt)



/* some macros to generate set/get funcs for the struct fields.  This

 * assumes there is a lefoo_to_cpu for every type, so lets make a simple

 * one for u8:
@@ -906,12 +914,6 @@ static inline u32 btrfs_level_size(struct btrfs_root *root, int level) { 
	((unsigned long)(btrfs_leaf_data(leaf) + \

	btrfs_item_offset_nr(leaf, slot)))



/* mount option defines and helpers */

#define BTRFS_MOUNT_SUBVOL		0x000001

#define btrfs_clear_opt(o, opt)		o &= ~BTRFS_MOUNT_##opt

#define btrfs_set_opt(o, opt)		o |= BTRFS_MOUNT_##opt

#define btrfs_test_opt(sb, opt)		(BTRFS_SB(sb)->s_mount_opt & \

					 BTRFS_MOUNT_##opt)

/* extent-tree.c */

int btrfs_extent_post_op(struct btrfs_trans_handle *trans,

			 struct btrfs_root *root);

fs/btrfs/disk-io.c

+1 −0
Original line number Diff line number Diff line
@@ -568,6 +568,7 @@ struct btrfs_root *open_ctree(struct super_block *sb) 
	fs_info->tree_root = tree_root;

	fs_info->extent_root = extent_root;

	fs_info->sb = sb;

	fs_info->mount_opt = 0;

	fs_info->btree_inode = new_inode(sb);

	fs_info->btree_inode->i_ino = 1;

	fs_info->btree_inode->i_nlink = 1;

fs/btrfs/inode.c

+10 −1
Original line number Diff line number Diff line
@@ -116,10 +116,13 @@ int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end) 
	struct btrfs_root *root = BTRFS_I(inode)->root;

	struct btrfs_trans_handle *trans;

	char *kaddr;

	int ret;

	int ret = 0;

	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;

	size_t offset = start - page_start;



	if (btrfs_test_opt(root, NODATASUM))

		return 0;



	mutex_lock(&root->fs_info->fs_mutex);

	trans = btrfs_start_transaction(root, 1);

	btrfs_set_trans_block_group(trans, inode);
@@ -143,6 +146,9 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end) 
	struct btrfs_path *path = NULL;

	u32 csum;



	if (btrfs_test_opt(root, NODATASUM))

		return 0;



	mutex_lock(&root->fs_info->fs_mutex);

	path = btrfs_alloc_path();

	item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
@@ -176,6 +182,9 @@ int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end) 
	u32 csum = ~(u32)0;

	unsigned long flags;



	if (btrfs_test_opt(root, NODATASUM))

		return 0;



	ret = get_state_private(em_tree, start, &private);

	local_irq_save(flags);

	kaddr = kmap_atomic(page, KM_IRQ0);

fs/btrfs/super.c

+15 −2
Original line number Diff line number Diff line
@@ -61,11 +61,12 @@ static void btrfs_put_super (struct super_block * sb) 
}



enum {

	Opt_subvol, Opt_err,

	Opt_subvol, Opt_nodatasum, Opt_err,

};



static match_table_t tokens = {

	{Opt_subvol, "subvol=%s"},

	{Opt_nodatasum, "nodatasum"},

	{Opt_err, NULL}

};
@@ -74,7 +75,12 @@ static int parse_options (char * options, 
			  char **subvol_name)

{

	char * p;

	struct btrfs_fs_info *info = NULL;

	substring_t args[MAX_OPT_ARGS];



	if (root)

		info = root->fs_info;



	if (!options)

		return 1;
@@ -86,8 +92,13 @@ static int parse_options (char * options, 
		token = match_token(p, tokens, args);

		switch (token) {

		case Opt_subvol:

			if (subvol_name)

				*subvol_name = match_strdup(&args[0]);

			break;

		case Opt_nodatasum:

			if (root)

				btrfs_set_opt(info->mount_opt, NODATASUM);

			break;

		default:

			return 0;

		}
@@ -143,6 +154,8 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent) 
		goto fail_close;

	}



	parse_options((char *)data, tree_root, NULL);



	/* this does the super kobj at the same time */

	err = btrfs_sysfs_add_super(tree_root->fs_info);

	if (err)