Commit 2833f4bb authored by Gao Xiang's avatar Gao Xiang
Browse files

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Fix some outdated comments and typos, hopefully helpful.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: default avatarYue Hu <huyue2@coolpad.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 1f7aa6ca

fs/erofs/erofs_fs.h

+21 −20
Original line number Diff line number Diff line
@@ -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;