提交 b6cda9bc 编写于 作者: C Chris Mason

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

Signed-off-by: NChris Mason <chris.mason@oracle.com>
上级 e9906a98
......@@ -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);
......
......@@ -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;
......
......@@ -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);
......
......@@ -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;
......@@ -86,7 +92,12 @@ static int parse_options (char * options,
token = match_token(p, tokens, args);
switch (token) {
case Opt_subvol:
*subvol_name = match_strdup(&args[0]);
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)
......
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