erofs: refine on-disk definition comments

Fix some outdated comments and typos, hopefully helpful.

Link: https://lore.kernel.org/r/20220506194612.117120-3-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Gao Xiang 2022-05-07 03:46:12 +08:00
parent 1f7aa6caef
commit 2833f4bb46

View File

@ -58,8 +58,8 @@ struct erofs_super_block {
__le16 root_nid; /* nid of root directory */
__le64 inos; /* total valid ino # (== f_files - f_favail) */
__le64 build_time; /* inode v1 time derivation */
__le32 build_time_nsec; /* inode v1 time derivation in nano scale */
__le64 build_time; /* compact inode time derivation */
__le32 build_time_nsec; /* compact inode time derivation in ns scale */
__le32 blocks; /* used for statfs */
__le32 meta_blkaddr; /* start block address of metadata area */
__le32 xattr_blkaddr; /* start block address of shared xattr area */
@ -79,15 +79,15 @@ struct erofs_super_block {
/*
* erofs inode datalayout (i_format in on-disk inode):
* 0 - inode plain without inline data A:
* 0 - uncompressed flat inode without tail-packing inline data:
* inode, [xattrs], ... | ... | no-holed data
* 1 - inode VLE compression B (legacy):
* inode, [xattrs], extents ... | ...
* 2 - inode plain with inline data C:
* inode, [xattrs], last_inline_data, ... | ... | no-holed data
* 3 - inode compression D:
* 1 - compressed inode with non-compact indexes:
* inode, [xattrs], [map_header], extents ... | ...
* 2 - uncompressed flat inode with tail-packing inline data:
* inode, [xattrs], tailpacking data, ... | ... | no-holed data
* 3 - compressed inode with compact indexes:
* inode, [xattrs], map_header, extents ... | ...
* 4 - inode chunk-based E:
* 4 - chunk-based inode with (optional) multi-device support:
* inode, [xattrs], chunk indexes ... | ...
* 5~7 - reserved
*/
@ -106,7 +106,7 @@ static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY;
}
/* bit definitions of inode i_advise */
/* bit definitions of inode i_format */
#define EROFS_I_VERSION_BITS 1
#define EROFS_I_DATALAYOUT_BITS 3
@ -140,8 +140,9 @@ struct erofs_inode_compact {
__le32 i_size;
__le32 i_reserved;
union {
/* file total compressed blocks for data mapping 1 */
/* total compressed blocks for compressed inodes */
__le32 compressed_blocks;
/* block address for uncompressed flat inodes */
__le32 raw_blkaddr;
/* for device files, used to indicate old/new device # */
@ -156,9 +157,9 @@ struct erofs_inode_compact {
__le32 i_reserved2;
};
/* 32 bytes on-disk inode */
/* 32-byte on-disk inode */
#define EROFS_INODE_LAYOUT_COMPACT 0
/* 64 bytes on-disk inode */
/* 64-byte on-disk inode */
#define EROFS_INODE_LAYOUT_EXTENDED 1
/* 64-byte complete form of an ondisk inode */
@ -171,8 +172,9 @@ struct erofs_inode_extended {
__le16 i_reserved;
__le64 i_size;
union {
/* file total compressed blocks for data mapping 1 */
/* total compressed blocks for compressed inodes */
__le32 compressed_blocks;
/* block address for uncompressed flat inodes */
__le32 raw_blkaddr;
/* for device files, used to indicate old/new device # */
@ -365,17 +367,16 @@ enum {
struct z_erofs_vle_decompressed_index {
__le16 di_advise;
/* where to decompress in the head cluster */
/* where to decompress in the head lcluster */
__le16 di_clusterofs;
union {
/* for the head cluster */
/* for the HEAD lclusters */
__le32 blkaddr;
/*
* for the rest clusters
* eg. for 4k page-sized cluster, maximum 4K*64k = 256M)
* [0] - pointing to the head cluster
* [1] - pointing to the tail cluster
* for the NONHEAD lclusters
* [0] - distance to its HEAD lcluster
* [1] - distance to the next HEAD lcluster
*/
__le16 delta[2];
} di_u;