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Diffstat (limited to 'fs/logfs/logfs_abi.h')
| -rw-r--r-- | fs/logfs/logfs_abi.h | 629 |
1 files changed, 0 insertions, 629 deletions
diff --git a/fs/logfs/logfs_abi.h b/fs/logfs/logfs_abi.h deleted file mode 100644 index ae960519c54a..000000000000 --- a/fs/logfs/logfs_abi.h +++ /dev/null @@ -1,629 +0,0 @@ -/* - * fs/logfs/logfs_abi.h - * - * As should be obvious for Linux kernel code, license is GPLv2 - * - * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> - * - * Public header for logfs. - */ -#ifndef FS_LOGFS_LOGFS_ABI_H -#define FS_LOGFS_LOGFS_ABI_H - -/* For out-of-kernel compiles */ -#ifndef BUILD_BUG_ON -#define BUILD_BUG_ON(condition) /**/ -#endif - -#define SIZE_CHECK(type, size) \ -static inline void check_##type(void) \ -{ \ - BUILD_BUG_ON(sizeof(struct type) != (size)); \ -} - -/* - * Throughout the logfs code, we're constantly dealing with blocks at - * various positions or offsets. To remove confusion, we stricly - * distinguish between a "position" - the logical position within a - * file and an "offset" - the physical location within the device. - * - * Any usage of the term offset for a logical location or position for - * a physical one is a bug and should get fixed. - */ - -/* - * Block are allocated in one of several segments depending on their - * level. The following levels are used: - * 0 - regular data block - * 1 - i1 indirect blocks - * 2 - i2 indirect blocks - * 3 - i3 indirect blocks - * 4 - i4 indirect blocks - * 5 - i5 indirect blocks - * 6 - ifile data blocks - * 7 - ifile i1 indirect blocks - * 8 - ifile i2 indirect blocks - * 9 - ifile i3 indirect blocks - * 10 - ifile i4 indirect blocks - * 11 - ifile i5 indirect blocks - * Potential levels to be used in the future: - * 12 - gc recycled blocks, long-lived data - * 13 - replacement blocks, short-lived data - * - * Levels 1-11 are necessary for robust gc operations and help separate - * short-lived metadata from longer-lived file data. In the future, - * file data should get separated into several segments based on simple - * heuristics. Old data recycled during gc operation is expected to be - * long-lived. New data is of uncertain life expectancy. New data - * used to replace older blocks in existing files is expected to be - * short-lived. - */ - - -/* Magic numbers. 64bit for superblock, 32bit for statfs f_type */ -#define LOGFS_MAGIC 0x7a3a8e5cb9d5bf67ull -#define LOGFS_MAGIC_U32 0xc97e8168u - -/* - * Various blocksize related macros. Blocksize is currently fixed at 4KiB. - * Sooner or later that should become configurable and the macros replaced - * by something superblock-dependent. Pointers in indirect blocks are and - * will remain 64bit. - * - * LOGFS_BLOCKSIZE - self-explaining - * LOGFS_BLOCK_FACTOR - number of pointers per indirect block - * LOGFS_BLOCK_BITS - log2 of LOGFS_BLOCK_FACTOR, used for shifts - */ -#define LOGFS_BLOCKSIZE (4096ull) -#define LOGFS_BLOCK_FACTOR (LOGFS_BLOCKSIZE / sizeof(u64)) -#define LOGFS_BLOCK_BITS (9) - -/* - * Number of blocks at various levels of indirection. There are 16 direct - * block pointers plus a single indirect pointer. - */ -#define I0_BLOCKS (16) -#define I1_BLOCKS LOGFS_BLOCK_FACTOR -#define I2_BLOCKS (LOGFS_BLOCK_FACTOR * I1_BLOCKS) -#define I3_BLOCKS (LOGFS_BLOCK_FACTOR * I2_BLOCKS) -#define I4_BLOCKS (LOGFS_BLOCK_FACTOR * I3_BLOCKS) -#define I5_BLOCKS (LOGFS_BLOCK_FACTOR * I4_BLOCKS) - -#define INDIRECT_INDEX I0_BLOCKS -#define LOGFS_EMBEDDED_FIELDS (I0_BLOCKS + 1) - -/* - * Sizes at which files require another level of indirection. Files smaller - * than LOGFS_EMBEDDED_SIZE can be completely stored in the inode itself, - * similar like ext2 fast symlinks. - * - * Data at a position smaller than LOGFS_I0_SIZE is accessed through the - * direct pointers, else through the 1x indirect pointer and so forth. - */ -#define LOGFS_EMBEDDED_SIZE (LOGFS_EMBEDDED_FIELDS * sizeof(u64)) -#define LOGFS_I0_SIZE (I0_BLOCKS * LOGFS_BLOCKSIZE) -#define LOGFS_I1_SIZE (I1_BLOCKS * LOGFS_BLOCKSIZE) -#define LOGFS_I2_SIZE (I2_BLOCKS * LOGFS_BLOCKSIZE) -#define LOGFS_I3_SIZE (I3_BLOCKS * LOGFS_BLOCKSIZE) -#define LOGFS_I4_SIZE (I4_BLOCKS * LOGFS_BLOCKSIZE) -#define LOGFS_I5_SIZE (I5_BLOCKS * LOGFS_BLOCKSIZE) - -/* - * Each indirect block pointer must have this flag set, if all block pointers - * behind it are set, i.e. there is no hole hidden in the shadow of this - * indirect block pointer. - */ -#define LOGFS_FULLY_POPULATED (1ULL << 63) -#define pure_ofs(ofs) (ofs & ~LOGFS_FULLY_POPULATED) - -/* - * LogFS needs to separate data into levels. Each level is defined as the - * maximal possible distance from the master inode (inode of the inode file). - * Data blocks reside on level 0, 1x indirect block on level 1, etc. - * Inodes reside on level 6, indirect blocks for the inode file on levels 7-11. - * This effort is necessary to guarantee garbage collection to always make - * progress. - * - * LOGFS_MAX_INDIRECT is the maximal indirection through indirect blocks, - * LOGFS_MAX_LEVELS is one more for the actual data level of a file. It is - * the maximal number of levels for one file. - * LOGFS_NO_AREAS is twice that, as the inode file and regular files are - * effectively stacked on top of each other. - */ -#define LOGFS_MAX_INDIRECT (5) -#define LOGFS_MAX_LEVELS (LOGFS_MAX_INDIRECT + 1) -#define LOGFS_NO_AREAS (2 * LOGFS_MAX_LEVELS) - -/* Maximum size of filenames */ -#define LOGFS_MAX_NAMELEN (255) - -/* Number of segments in the primary journal. */ -#define LOGFS_JOURNAL_SEGS (16) - -/* Maximum number of free/erased/etc. segments in journal entries */ -#define MAX_CACHED_SEGS (64) - - -/* - * LOGFS_OBJECT_HEADERSIZE is the size of a single header in the object store, - * LOGFS_MAX_OBJECTSIZE the size of the largest possible object, including - * its header, - * LOGFS_SEGMENT_RESERVE is the amount of space reserved for each segment for - * its segment header and the padded space at the end when no further objects - * fit. - */ -#define LOGFS_OBJECT_HEADERSIZE (0x1c) -#define LOGFS_SEGMENT_HEADERSIZE (0x18) -#define LOGFS_MAX_OBJECTSIZE (LOGFS_OBJECT_HEADERSIZE + LOGFS_BLOCKSIZE) -#define LOGFS_SEGMENT_RESERVE \ - (LOGFS_SEGMENT_HEADERSIZE + LOGFS_MAX_OBJECTSIZE - 1) - -/* - * Segment types: - * SEG_SUPER - Data or indirect block - * SEG_JOURNAL - Inode - * SEG_OSTORE - Dentry - */ -enum { - SEG_SUPER = 0x01, - SEG_JOURNAL = 0x02, - SEG_OSTORE = 0x03, -}; - -/** - * struct logfs_segment_header - per-segment header in the ostore - * - * @crc: crc32 of header (there is no data) - * @pad: unused, must be 0 - * @type: segment type, see above - * @level: GC level for all objects in this segment - * @segno: segment number - * @ec: erase count for this segment - * @gec: global erase count at time of writing - */ -struct logfs_segment_header { - __be32 crc; - __be16 pad; - __u8 type; - __u8 level; - __be32 segno; - __be32 ec; - __be64 gec; -}; - -SIZE_CHECK(logfs_segment_header, LOGFS_SEGMENT_HEADERSIZE); - -#define LOGFS_FEATURES_INCOMPAT (0ull) -#define LOGFS_FEATURES_RO_COMPAT (0ull) -#define LOGFS_FEATURES_COMPAT (0ull) - -/** - * struct logfs_disk_super - on-medium superblock - * - * @ds_magic: magic number, must equal LOGFS_MAGIC - * @ds_crc: crc32 of structure starting with the next field - * @ds_ifile_levels: maximum number of levels for ifile - * @ds_iblock_levels: maximum number of levels for regular files - * @ds_data_levels: number of separate levels for data - * @pad0: reserved, must be 0 - * @ds_feature_incompat: incompatible filesystem features - * @ds_feature_ro_compat: read-only compatible filesystem features - * @ds_feature_compat: compatible filesystem features - * @ds_flags: flags - * @ds_segment_shift: log2 of segment size - * @ds_block_shift: log2 of block size - * @ds_write_shift: log2 of write size - * @pad1: reserved, must be 0 - * @ds_journal_seg: segments used by primary journal - * @ds_root_reserve: bytes reserved for the superuser - * @ds_speed_reserve: bytes reserved to speed up GC - * @ds_bad_seg_reserve: number of segments reserved to handle bad blocks - * @pad2: reserved, must be 0 - * @pad3: reserved, must be 0 - * - * Contains only read-only fields. Read-write fields like the amount of used - * space is tracked in the dynamic superblock, which is stored in the journal. - */ -struct logfs_disk_super { - struct logfs_segment_header ds_sh; - __be64 ds_magic; - - __be32 ds_crc; - __u8 ds_ifile_levels; - __u8 ds_iblock_levels; - __u8 ds_data_levels; - __u8 ds_segment_shift; - __u8 ds_block_shift; - __u8 ds_write_shift; - __u8 pad0[6]; - - __be64 ds_filesystem_size; - __be32 ds_segment_size; - __be32 ds_bad_seg_reserve; - - __be64 ds_feature_incompat; - __be64 ds_feature_ro_compat; - - __be64 ds_feature_compat; - __be64 ds_feature_flags; - - __be64 ds_root_reserve; - __be64 ds_speed_reserve; - - __be32 ds_journal_seg[LOGFS_JOURNAL_SEGS]; - - __be64 ds_super_ofs[2]; - __be64 pad3[8]; -}; - -SIZE_CHECK(logfs_disk_super, 256); - -/* - * Object types: - * OBJ_BLOCK - Data or indirect block - * OBJ_INODE - Inode - * OBJ_DENTRY - Dentry - */ -enum { - OBJ_BLOCK = 0x04, - OBJ_INODE = 0x05, - OBJ_DENTRY = 0x06, -}; - -/** - * struct logfs_object_header - per-object header in the ostore - * - * @crc: crc32 of header, excluding data_crc - * @len: length of data - * @type: object type, see above - * @compr: compression type - * @ino: inode number - * @bix: block index - * @data_crc: crc32 of payload - */ -struct logfs_object_header { - __be32 crc; - __be16 len; - __u8 type; - __u8 compr; - __be64 ino; - __be64 bix; - __be32 data_crc; -} __attribute__((packed)); - -SIZE_CHECK(logfs_object_header, LOGFS_OBJECT_HEADERSIZE); - -/* - * Reserved inode numbers: - * LOGFS_INO_MASTER - master inode (for inode file) - * LOGFS_INO_ROOT - root directory - * LOGFS_INO_SEGFILE - per-segment used bytes and erase count - */ -enum { - LOGFS_INO_MAPPING = 0x00, - LOGFS_INO_MASTER = 0x01, - LOGFS_INO_ROOT = 0x02, - LOGFS_INO_SEGFILE = 0x03, - LOGFS_RESERVED_INOS = 0x10, -}; - -/* - * Inode flags. High bits should never be written to the medium. They are - * reserved for in-memory usage. - * Low bits should either remain in sync with the corresponding FS_*_FL or - * reuse slots that obviously don't make sense for logfs. - * - * LOGFS_IF_DIRTY Inode must be written back - * LOGFS_IF_ZOMBIE Inode has been deleted - * LOGFS_IF_STILLBORN -ENOSPC happened when creating inode - */ -#define LOGFS_IF_COMPRESSED 0x00000004 /* == FS_COMPR_FL */ -#define LOGFS_IF_DIRTY 0x20000000 -#define LOGFS_IF_ZOMBIE 0x40000000 -#define LOGFS_IF_STILLBORN 0x80000000 - -/* Flags available to chattr */ -#define LOGFS_FL_USER_VISIBLE (LOGFS_IF_COMPRESSED) -#define LOGFS_FL_USER_MODIFIABLE (LOGFS_IF_COMPRESSED) -/* Flags inherited from parent directory on file/directory creation */ -#define LOGFS_FL_INHERITED (LOGFS_IF_COMPRESSED) - -/** - * struct logfs_disk_inode - on-medium inode - * - * @di_mode: file mode - * @di_pad: reserved, must be 0 - * @di_flags: inode flags, see above - * @di_uid: user id - * @di_gid: group id - * @di_ctime: change time - * @di_mtime: modify time - * @di_refcount: reference count (aka nlink or link count) - * @di_generation: inode generation, for nfs - * @di_used_bytes: number of bytes used - * @di_size: file size - * @di_data: data pointers - */ -struct logfs_disk_inode { - __be16 di_mode; - __u8 di_height; - __u8 di_pad; - __be32 di_flags; - __be32 di_uid; - __be32 di_gid; - - __be64 di_ctime; - __be64 di_mtime; - - __be64 di_atime; - __be32 di_refcount; - __be32 di_generation; - - __be64 di_used_bytes; - __be64 di_size; - - __be64 di_data[LOGFS_EMBEDDED_FIELDS]; -}; - -SIZE_CHECK(logfs_disk_inode, 200); - -#define INODE_POINTER_OFS \ - (offsetof(struct logfs_disk_inode, di_data) / sizeof(__be64)) -#define INODE_USED_OFS \ - (offsetof(struct logfs_disk_inode, di_used_bytes) / sizeof(__be64)) -#define INODE_SIZE_OFS \ - (offsetof(struct logfs_disk_inode, di_size) / sizeof(__be64)) -#define INODE_HEIGHT_OFS (0) - -/** - * struct logfs_disk_dentry - on-medium dentry structure - * - * @ino: inode number - * @namelen: length of file name - * @type: file type, identical to bits 12..15 of mode - * @name: file name - */ -/* FIXME: add 6 bytes of padding to remove the __packed */ -struct logfs_disk_dentry { - __be64 ino; - __be16 namelen; - __u8 type; - __u8 name[LOGFS_MAX_NAMELEN]; -} __attribute__((packed)); - -SIZE_CHECK(logfs_disk_dentry, 266); - -#define RESERVED 0xffffffff -#define BADSEG 0xffffffff -/** - * struct logfs_segment_entry - segment file entry - * - * @ec_level: erase count and level - * @valid: number of valid bytes - * - * Segment file contains one entry for every segment. ec_level contains the - * erasecount in the upper 28 bits and the level in the lower 4 bits. An - * ec_level of BADSEG (-1) identifies bad segments. valid contains the number - * of valid bytes or RESERVED (-1 again) if the segment is used for either the - * superblock or the journal, or when the segment is bad. - */ -struct logfs_segment_entry { - __be32 ec_level; - __be32 valid; -}; - -SIZE_CHECK(logfs_segment_entry, 8); - -/** - * struct logfs_journal_header - header for journal entries (JEs) - * - * @h_crc: crc32 of journal entry - * @h_len: length of compressed journal entry, - * not including header - * @h_datalen: length of uncompressed data - * @h_type: JE type - * @h_compr: compression type - * @h_pad: reserved - */ -struct logfs_journal_header { - __be32 h_crc; - __be16 h_len; - __be16 h_datalen; - __be16 h_type; - __u8 h_compr; - __u8 h_pad[5]; -}; - -SIZE_CHECK(logfs_journal_header, 16); - -/* - * Life expectency of data. - * VIM_DEFAULT - default vim - * VIM_SEGFILE - for segment file only - very short-living - * VIM_GC - GC'd data - likely long-living - */ -enum logfs_vim { - VIM_DEFAULT = 0, - VIM_SEGFILE = 1, -}; - -/** - * struct logfs_je_area - wbuf header - * - * @segno: segment number of area - * @used_bytes: number of bytes already used - * @gc_level: GC level - * @vim: life expectancy of data - * - * "Areas" are segments currently being used for writing. There is at least - * one area per GC level. Several may be used to separate long-living from - * short-living data. If an area with unknown vim is encountered, it can - * simply be closed. - * The write buffer immediately follow this header. - */ -struct logfs_je_area { - __be32 segno; - __be32 used_bytes; - __u8 gc_level; - __u8 vim; -} __attribute__((packed)); - -SIZE_CHECK(logfs_je_area, 10); - -#define MAX_JOURNAL_HEADER \ - (sizeof(struct logfs_journal_header) + sizeof(struct logfs_je_area)) - -/** - * struct logfs_je_dynsb - dynamic superblock - * - * @ds_gec: global erase count - * @ds_sweeper: current position of GC "sweeper" - * @ds_rename_dir: source directory ino (see dir.c documentation) - * @ds_rename_pos: position of source dd (see dir.c documentation) - * @ds_victim_ino: victims of incomplete dir operation (see dir.c) - * @ds_victim_ino: parent inode of victim (see dir.c) - * @ds_used_bytes: number of used bytes - */ -struct logfs_je_dynsb { - __be64 ds_gec; - __be64 ds_sweeper; - - __be64 ds_rename_dir; - __be64 ds_rename_pos; - - __be64 ds_victim_ino; - __be64 ds_victim_parent; /* XXX */ - - __be64 ds_used_bytes; - __be32 ds_generation; - __be32 pad; -}; - -SIZE_CHECK(logfs_je_dynsb, 64); - -/** - * struct logfs_je_anchor - anchor of filesystem tree, aka master inode - * - * @da_size: size of inode file - * @da_last_ino: last created inode - * @da_used_bytes: number of bytes used - * @da_data: data pointers - */ -struct logfs_je_anchor { - __be64 da_size; - __be64 da_last_ino; - - __be64 da_used_bytes; - u8 da_height; - u8 pad[7]; - - __be64 da_data[LOGFS_EMBEDDED_FIELDS]; -}; - -SIZE_CHECK(logfs_je_anchor, 168); - -/** - * struct logfs_je_spillout - spillout entry (from 1st to 2nd journal) - * - * @so_segment: segments used for 2nd journal - * - * Length of the array is given by h_len field in the header. - */ -struct logfs_je_spillout { - __be64 so_segment[0]; -}; - -SIZE_CHECK(logfs_je_spillout, 0); - -/** - * struct logfs_je_journal_ec - erase counts for all journal segments - * - * @ec: erase count - * - * Length of the array is given by h_len field in the header. - */ -struct logfs_je_journal_ec { - __be32 ec[0]; -}; - -SIZE_CHECK(logfs_je_journal_ec, 0); - -/** - * struct logfs_je_free_segments - list of free segmetns with erase count - */ -struct logfs_je_free_segments { - __be32 segno; - __be32 ec; -}; - -SIZE_CHECK(logfs_je_free_segments, 8); - -/** - * struct logfs_seg_alias - list of segment aliases - */ -struct logfs_seg_alias { - __be32 old_segno; - __be32 new_segno; -}; - -SIZE_CHECK(logfs_seg_alias, 8); - -/** - * struct logfs_obj_alias - list of object aliases - */ -struct logfs_obj_alias { - __be64 ino; - __be64 bix; - __be64 val; - u8 level; - u8 pad[5]; - __be16 child_no; -}; - -SIZE_CHECK(logfs_obj_alias, 32); - -/** - * Compression types. - * - * COMPR_NONE - uncompressed - * COMPR_ZLIB - compressed with zlib - */ -enum { - COMPR_NONE = 0, - COMPR_ZLIB = 1, -}; - -/* - * Journal entries come in groups of 16. First group contains unique - * entries, next groups contain one entry per level - * - * JE_FIRST - smallest possible journal entry number - * - * JEG_BASE - base group, containing unique entries - * JE_COMMIT - commit entry, validates all previous entries - * JE_DYNSB - dynamic superblock, anything that ought to be in the - * superblock but cannot because it is read-write data - * JE_ANCHOR - anchor aka master inode aka inode file's inode - * JE_ERASECOUNT erasecounts for all journal segments - * JE_SPILLOUT - unused - * JE_SEG_ALIAS - aliases segments - * JE_AREA - area description - * - * JE_LAST - largest possible journal entry number - */ -enum { - JE_FIRST = 0x01, - - JEG_BASE = 0x00, - JE_COMMIT = 0x02, - JE_DYNSB = 0x03, - JE_ANCHOR = 0x04, - JE_ERASECOUNT = 0x05, - JE_SPILLOUT = 0x06, - JE_OBJ_ALIAS = 0x0d, - JE_AREA = 0x0e, - - JE_LAST = 0x0e, -}; - -#endif |