From c830821ddf963037cee381fa004b3df0a5296a1b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 29 Oct 2008 14:37:41 -0400 Subject: Add disk format elements for compression Signed-off-by: Chris Mason --- ctree.h | 51 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 4 deletions(-) (limited to 'ctree.h') diff --git a/ctree.h b/ctree.h index 860b89b7..9b16275b 100644 --- a/ctree.h +++ b/ctree.h @@ -377,10 +377,18 @@ struct btrfs_timespec { __le32 nsec; } __attribute__ ((__packed__)); -/* - * there is no padding here on purpose. If you want to extent the inode, - * make a new item type - */ +typedef enum { + BTRFS_COMPRESS_NONE = 0, + BTRFS_COMPRESS_ZLIB = 1, + BTRFS_COMPRESS_LAST = 2, +} btrfs_compression_type; + +/* we don't understand any encryption methods right now */ +typedef enum { + BTRFS_ENCRYPTION_NONE = 0, + BTRFS_ENCRYPTION_LAST = 1, +} btrfs_encryption_type; + struct btrfs_inode_item { /* nfs style generation number */ __le64 generation; @@ -396,6 +404,7 @@ struct btrfs_inode_item { __le64 rdev; __le16 flags; __le16 compat_flags; + struct btrfs_timespec atime; struct btrfs_timespec ctime; struct btrfs_timespec mtime; @@ -427,8 +436,33 @@ struct btrfs_root_item { #define BTRFS_FILE_EXTENT_INLINE 1 struct btrfs_file_extent_item { + /* + * transaction id that created this extent + */ __le64 generation; + /* + * max number of bytes to hold this extent in ram + * when we split a compressed extent we can't know how big + * each of the resulting pieces will be. So, this is + * an upper limit on the size of the extent in ram instead of + * an exact limit. + */ + __le64 ram_bytes; + + /* + * 32 bits for the various ways we might encode the data, + * including compression and encryption. If any of these + * are set to something a given disk format doesn't understand + * it is treated like an incompat flag for reading and writing, + * but not for stat. + */ + u8 compression; + u8 encryption; + __le16 other_encoding; /* spare for later use */ + + /* are we inline data or a real extent? */ u8 type; + /* * disk space consumed by the extent, checksum blocks are included * in these numbers @@ -447,6 +481,7 @@ struct btrfs_file_extent_item { * the logical number of file blocks (no csums included) */ __le64 num_bytes; + } __attribute__ ((__packed__)); struct btrfs_csum_item { @@ -1284,6 +1319,14 @@ BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item, offset, 64); BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item, num_bytes, 64); +BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item, + ram_bytes, 64); +BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item, + compression, 8); +BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item, + encryption, 8); +BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item, + other_encoding, 16); static inline u32 btrfs_level_size(struct btrfs_root *root, int level) { if (level == 0) -- cgit v1.2.3