btrfs-progs: export read_extent_data function

Export it for later btrfs-map-logical cleanup.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
Qu Wenruo 2015-06-17 15:49:00 +08:00 committed by David Sterba
parent cf4eb9a90e
commit 0074cd315c
3 changed files with 36 additions and 34 deletions

View File

@ -5235,40 +5235,6 @@ static int check_space_cache(struct btrfs_root *root)
return error ? -EINVAL : 0;
}
static int read_extent_data(struct btrfs_root *root, char *data,
u64 logical, u64 *len, int mirror)
{
u64 offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_device *device;
int ret = 0;
u64 max_len = *len;
ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
&multi, mirror, NULL);
if (ret) {
fprintf(stderr, "Couldn't map the block %llu\n",
logical + offset);
goto err;
}
device = multi->stripes[0].dev;
if (device->fd == 0)
goto err;
if (*len > max_len)
*len = max_len;
ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
if (ret != *len)
ret = -EIO;
else
ret = 0;
err:
kfree(multi);
return ret;
}
static int check_extent_csums(struct btrfs_root *root, u64 bytenr,
u64 num_bytes, unsigned long leaf_offset,
struct extent_buffer *eb) {

View File

@ -366,6 +366,40 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
return ERR_PTR(ret);
}
int read_extent_data(struct btrfs_root *root, char *data,
u64 logical, u64 *len, int mirror)
{
u64 offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_device *device;
int ret = 0;
u64 max_len = *len;
ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
&multi, mirror, NULL);
if (ret) {
fprintf(stderr, "Couldn't map the block %llu\n",
logical + offset);
goto err;
}
device = multi->stripes[0].dev;
if (device->fd == 0)
goto err;
if (*len > max_len)
*len = max_len;
ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
if (ret != *len)
ret = -EIO;
else
ret = 0;
err:
kfree(multi);
return ret;
}
int write_and_map_eb(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)

View File

@ -69,6 +69,8 @@ struct btrfs_device;
int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror);
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid);
int read_extent_data(struct btrfs_root *root, char *data, u64 logical,
u64 *len, int mirror);
void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
u64 parent_transid);
struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,