Btrfs-progs: map-logical: introduce print_mapping_info function

The new function will print the mapping info of given range
[logical, logical+len).

Note, caller must ensure the ranges are completely inside an extent.
Or btrfs_map_block can return -ENOENT.

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 15:49:02 +08:00 committed by David Sterba
parent 02454f307b
commit 1e28ed2f84

View File

@ -93,6 +93,69 @@ out:
return ret;
}
static int __print_mapping_info(struct btrfs_fs_info *fs_info, u64 logical,
u64 len, int mirror_num)
{
struct btrfs_multi_bio *multi = NULL;
u64 cur_offset = 0;
u64 cur_len;
int ret = 0;
while (cur_offset < len) {
struct btrfs_device *device;
int i;
cur_len = len - cur_offset;
ret = btrfs_map_block(&fs_info->mapping_tree, READ,
logical + cur_offset, &cur_len,
&multi, mirror_num, NULL);
if (ret) {
fprintf(info_file,
"Error: fails to map mirror%d logical %llu: %s\n",
mirror_num, logical, strerror(-ret));
return ret;
}
for (i = 0; i < multi->num_stripes; i++) {
device = multi->stripes[i].dev;
fprintf(info_file,
"mirror %d logical %Lu physical %Lu device %s\n",
mirror_num, logical + cur_offset,
multi->stripes[0].physical,
device->name);
}
kfree(multi);
multi = NULL;
cur_offset += cur_len;
}
return ret;
}
/*
* Logical and len is the exact value of a extent.
* And offset is the offset inside the extent. It's only used for case
* where user only want to print part of the extent.
*
* Caller *MUST* ensure the range [logical,logical+len) are in one extent.
* Or we can encounter the following case, causing a -ENOENT error:
* |<-----given parameter------>|
* |<------ Extent A ----->|
*/
static int print_mapping_info(struct btrfs_fs_info *fs_info, u64 logical,
u64 len)
{
int num_copies;
int mirror_num;
int ret = 0;
num_copies = btrfs_num_copies(&fs_info->mapping_tree, logical, len);
for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
ret = __print_mapping_info(fs_info, logical, len, mirror_num);
if (ret < 0)
return ret;
}
return ret;
}
static struct extent_buffer * debug_read_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize, u64 copy)
{