diff options
Diffstat (limited to 'include/uapi/linux/btrfs.h')
| -rw-r--r-- | include/uapi/linux/btrfs.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index 738619994e26..d956b2993970 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -309,6 +309,7 @@ struct btrfs_ioctl_fs_info_args { #define BTRFS_FEATURE_INCOMPAT_METADATA_UUID (1ULL << 10) #define BTRFS_FEATURE_INCOMPAT_RAID1C34 (1ULL << 11) #define BTRFS_FEATURE_INCOMPAT_ZONED (1ULL << 12) +#define BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 (1ULL << 13) struct btrfs_ioctl_feature_flags { __u64 compat_flags; @@ -868,6 +869,134 @@ struct btrfs_ioctl_get_subvol_rootref_args { __u8 align[7]; }; +/* + * Data and metadata for an encoded read or write. + * + * Encoded I/O bypasses any encoding automatically done by the filesystem (e.g., + * compression). This can be used to read the compressed contents of a file or + * write pre-compressed data directly to a file. + * + * BTRFS_IOC_ENCODED_READ and BTRFS_IOC_ENCODED_WRITE are essentially + * preadv/pwritev with additional metadata about how the data is encoded and the + * size of the unencoded data. + * + * BTRFS_IOC_ENCODED_READ fills the given iovecs with the encoded data, fills + * the metadata fields, and returns the size of the encoded data. It reads one + * extent per call. It can also read data which is not encoded. + * + * BTRFS_IOC_ENCODED_WRITE uses the metadata fields, writes the encoded data + * from the iovecs, and returns the size of the encoded data. Note that the + * encoded data is not validated when it is written; if it is not valid (e.g., + * it cannot be decompressed), then a subsequent read may return an error. + * + * Since the filesystem page cache contains decoded data, encoded I/O bypasses + * the page cache. Encoded I/O requires CAP_SYS_ADMIN. + */ +struct btrfs_ioctl_encoded_io_args { + /* Input parameters for both reads and writes. */ + + /* + * iovecs containing encoded data. + * + * For reads, if the size of the encoded data is larger than the sum of + * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with + * ENOBUFS. + * + * For writes, the size of the encoded data is the sum of iov[n].iov_len + * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may + * increase in the future). This must also be less than or equal to + * unencoded_len. + */ + const struct iovec __user *iov; + /* Number of iovecs. */ + unsigned long iovcnt; + /* + * Offset in file. + * + * For writes, must be aligned to the sector size of the filesystem. + */ + __s64 offset; + /* Currently must be zero. */ + __u64 flags; + + /* + * For reads, the following members are output parameters that will + * contain the returned metadata for the encoded data. + * For writes, the following members must be set to the metadata for the + * encoded data. + */ + + /* + * Length of the data in the file. + * + * Must be less than or equal to unencoded_len - unencoded_offset. For + * writes, must be aligned to the sector size of the filesystem unless + * the data ends at or beyond the current end of the file. + */ + __u64 len; + /* + * Length of the unencoded (i.e., decrypted and decompressed) data. + * + * For writes, must be no more than 128 KiB (this limit may increase in + * the future). If the unencoded data is actually longer than + * unencoded_len, then it is truncated; if it is shorter, then it is + * extended with zeroes. + */ + __u64 unencoded_len; + /* + * Offset from the first byte of the unencoded data to the first byte of + * logical data in the file. + * + * Must be less than unencoded_len. + */ + __u64 unencoded_offset; + /* + * BTRFS_ENCODED_IO_COMPRESSION_* type. + * + * For writes, must not be BTRFS_ENCODED_IO_COMPRESSION_NONE. + */ + __u32 compression; + /* Currently always BTRFS_ENCODED_IO_ENCRYPTION_NONE. */ + __u32 encryption; + /* + * Reserved for future expansion. + * + * For reads, always returned as zero. Users should check for non-zero + * bytes. If there are any, then the kernel has a newer version of this + * structure with additional information that the user definition is + * missing. + * + * For writes, must be zeroed. + */ + __u8 reserved[64]; +}; + +/* Data is not compressed. */ +#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0 +/* Data is compressed as a single zlib stream. */ +#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1 +/* + * Data is compressed as a single zstd frame with the windowLog compression + * parameter set to no more than 17. + */ +#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2 +/* + * Data is compressed sector by sector (using the sector size indicated by the + * name of the constant) with LZO1X and wrapped in the format documented in + * fs/btrfs/lzo.c. For writes, the compression sector size must match the + * filesystem sector size. + */ +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3 +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4 +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5 +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6 +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7 +#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8 + +/* Data is not encrypted. */ +#define BTRFS_ENCODED_IO_ENCRYPTION_NONE 0 +#define BTRFS_ENCODED_IO_ENCRYPTION_TYPES 1 + /* Error codes as returned by the kernel */ enum btrfs_err_code { BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET = 1, @@ -996,5 +1125,9 @@ enum btrfs_err_code { struct btrfs_ioctl_ino_lookup_user_args) #define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \ struct btrfs_ioctl_vol_args_v2) +#define BTRFS_IOC_ENCODED_READ _IOR(BTRFS_IOCTL_MAGIC, 64, \ + struct btrfs_ioctl_encoded_io_args) +#define BTRFS_IOC_ENCODED_WRITE _IOW(BTRFS_IOCTL_MAGIC, 64, \ + struct btrfs_ioctl_encoded_io_args) #endif /* _UAPI_LINUX_BTRFS_H */ |