GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

btrfs: offline dedupe

Browse source 
This patch adds an ioctl, BTRFS_IOC_FILE_EXTENT_SAME which will try to
de-duplicate a list of extents across a range of files.

Internally, the ioctl re-uses code from the clone ioctl. This avoids
rewriting a large chunk of extent handling code.

Userspace passes in an array of file, offset pairs along with a length
argument. The ioctl will then (for each dedupe) do a byte-by-byte comparison
of the user data before deduping the extent. Status and number of bytes
deduped are returned for each operation.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Mark Fasheh 2013-08-06 11:42:51 -07:00 • committed by Chris Mason
parent 4b384318a7
commit 416161db9b
2 changed files with 307 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

28
include/uapi/linux/btrfs.h
View file

@ -305,6 +305,31 @@ struct btrfs_ioctl_clone_range_args {
#define BTRFS_DEFRAG_RANGE_COMPRESS 1
#define BTRFS_DEFRAG_RANGE_START_IO 2
#define BTRFS_SAME_DATA_DIFFERS 1
/* For extent-same ioctl */
struct btrfs_ioctl_same_extent_info {
__s64 fd; /* in - destination file */
__u64 logical_offset; /* in - start of extent in destination */
__u64 bytes_deduped; /* out - total # of bytes we were able
* to dedupe from this file */
/* status of this dedupe operation:
* 0 if dedup succeeds
* < 0 for error
* == BTRFS_SAME_DATA_DIFFERS if data differs
*/
__s32 status; /* out - see above description */
__u32 reserved;
};
struct btrfs_ioctl_same_args {
__u64 logical_offset; /* in - start of extent in source */
__u64 length; /* in - length of extent */
__u16 dest_count; /* in - total elements in info array */
__u16 reserved1;
__u32 reserved2;
struct btrfs_ioctl_same_extent_info info[0];
};
struct btrfs_ioctl_space_info {
__u64 flags;
__u64 total_bytes;
@ -579,4 +604,7 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
struct btrfs_ioctl_get_dev_stats)
#define BTRFS_IOC_DEV_REPLACE _IOWR(BTRFS_IOCTL_MAGIC, 53, \
struct btrfs_ioctl_dev_replace_args)
#define BTRFS_IOC_FILE_EXTENT_SAME _IOWR(BTRFS_IOCTL_MAGIC, 54, \
struct btrfs_ioctl_same_args)
#endif /* _UAPI_LINUX_BTRFS_H */