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Diffstat (limited to 'fs/hpfs/hpfs.h')
| -rw-r--r-- | fs/hpfs/hpfs.h | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h new file mode 100644 index 000000000..823a32879 --- /dev/null +++ b/fs/hpfs/hpfs.h @@ -0,0 +1,560 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/fs/hpfs/hpfs.h + * + * HPFS structures by Chris Smith, 1993 + * + * a little bit modified by Mikulas Patocka, 1998-1999 + */ + +/* The paper + + Duncan, Roy + Design goals and implementation of the new High Performance File System + Microsoft Systems Journal Sept 1989 v4 n5 p1(13) + + describes what HPFS looked like when it was new, and it is the source + of most of the information given here. The rest is conjecture. + + For definitive information on the Duncan paper, see it, not this file. + For definitive information on HPFS, ask somebody else -- this is guesswork. + There are certain to be many mistakes. */ + +#if !defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN) +#error unknown endian +#endif + +/* Notation */ + +typedef u32 secno; /* sector number, partition relative */ + +typedef secno dnode_secno; /* sector number of a dnode */ +typedef secno fnode_secno; /* sector number of an fnode */ +typedef secno anode_secno; /* sector number of an anode */ + +typedef u32 time32_t; /* 32-bit time_t type */ + +/* sector 0 */ + +/* The boot block is very like a FAT boot block, except that the + 29h signature byte is 28h instead, and the ID string is "HPFS". */ + +#define BB_MAGIC 0xaa55 + +struct hpfs_boot_block +{ + u8 jmp[3]; + u8 oem_id[8]; + u8 bytes_per_sector[2]; /* 512 */ + u8 sectors_per_cluster; + u8 n_reserved_sectors[2]; + u8 n_fats; + u8 n_rootdir_entries[2]; + u8 n_sectors_s[2]; + u8 media_byte; + __le16 sectors_per_fat; + __le16 sectors_per_track; + __le16 heads_per_cyl; + __le32 n_hidden_sectors; + __le32 n_sectors_l; /* size of partition */ + u8 drive_number; + u8 mbz; + u8 sig_28h; /* 28h */ + u8 vol_serno[4]; + u8 vol_label[11]; + u8 sig_hpfs[8]; /* "HPFS " */ + u8 pad[448]; + __le16 magic; /* aa55 */ +}; + + +/* sector 16 */ + +/* The super block has the pointer to the root directory. */ + +#define SB_MAGIC 0xf995e849 + +struct hpfs_super_block +{ + __le32 magic; /* f995 e849 */ + __le32 magic1; /* fa53 e9c5, more magic? */ + u8 version; /* version of a filesystem usually 2 */ + u8 funcversion; /* functional version - oldest version + of filesystem that can understand + this disk */ + __le16 zero; /* 0 */ + __le32 root; /* fnode of root directory */ + __le32 n_sectors; /* size of filesystem */ + __le32 n_badblocks; /* number of bad blocks */ + __le32 bitmaps; /* pointers to free space bit maps */ + __le32 zero1; /* 0 */ + __le32 badblocks; /* bad block list */ + __le32 zero3; /* 0 */ + __le32 last_chkdsk; /* date last checked, 0 if never */ + __le32 last_optimize; /* date last optimized, 0 if never */ + __le32 n_dir_band; /* number of sectors in dir band */ + __le32 dir_band_start; /* first sector in dir band */ + __le32 dir_band_end; /* last sector in dir band */ + __le32 dir_band_bitmap; /* free space map, 1 dnode per bit */ + u8 volume_name[32]; /* not used */ + __le32 user_id_table; /* 8 preallocated sectors - user id */ + u32 zero6[103]; /* 0 */ +}; + + +/* sector 17 */ + +/* The spare block has pointers to spare sectors. */ + +#define SP_MAGIC 0xf9911849 + +struct hpfs_spare_block +{ + __le32 magic; /* f991 1849 */ + __le32 magic1; /* fa52 29c5, more magic? */ + +#ifdef __LITTLE_ENDIAN + u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */ + u8 sparedir_used: 1; /* spare dirblks used */ + u8 hotfixes_used: 1; /* hotfixes used */ + u8 bad_sector: 1; /* bad sector, corrupted disk (???) */ + u8 bad_bitmap: 1; /* bad bitmap */ + u8 fast: 1; /* partition was fast formatted */ + u8 old_wrote: 1; /* old version wrote to partion */ + u8 old_wrote_1: 1; /* old version wrote to partion (?) */ +#else + u8 old_wrote_1: 1; /* old version wrote to partion (?) */ + u8 old_wrote: 1; /* old version wrote to partion */ + u8 fast: 1; /* partition was fast formatted */ + u8 bad_bitmap: 1; /* bad bitmap */ + u8 bad_sector: 1; /* bad sector, corrupted disk (???) */ + u8 hotfixes_used: 1; /* hotfixes used */ + u8 sparedir_used: 1; /* spare dirblks used */ + u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */ +#endif + +#ifdef __LITTLE_ENDIAN + u8 install_dasd_limits: 1; /* HPFS386 flags */ + u8 resynch_dasd_limits: 1; + u8 dasd_limits_operational: 1; + u8 multimedia_active: 1; + u8 dce_acls_active: 1; + u8 dasd_limits_dirty: 1; + u8 flag67: 2; +#else + u8 flag67: 2; + u8 dasd_limits_dirty: 1; + u8 dce_acls_active: 1; + u8 multimedia_active: 1; + u8 dasd_limits_operational: 1; + u8 resynch_dasd_limits: 1; + u8 install_dasd_limits: 1; /* HPFS386 flags */ +#endif + + u8 mm_contlgulty; + u8 unused; + + __le32 hotfix_map; /* info about remapped bad sectors */ + __le32 n_spares_used; /* number of hotfixes */ + __le32 n_spares; /* number of spares in hotfix map */ + __le32 n_dnode_spares_free; /* spare dnodes unused */ + __le32 n_dnode_spares; /* length of spare_dnodes[] list, + follows in this block*/ + __le32 code_page_dir; /* code page directory block */ + __le32 n_code_pages; /* number of code pages */ + __le32 super_crc; /* on HPFS386 and LAN Server this is + checksum of superblock, on normal + OS/2 unused */ + __le32 spare_crc; /* on HPFS386 checksum of spareblock */ + __le32 zero1[15]; /* unused */ + __le32 spare_dnodes[100]; /* emergency free dnode list */ + __le32 zero2[1]; /* room for more? */ +}; + +/* The bad block list is 4 sectors long. The first word must be zero, + the remaining words give n_badblocks bad block numbers. + I bet you can see it coming... */ + +#define BAD_MAGIC 0 + +/* The hotfix map is 4 sectors long. It looks like + + secno from[n_spares]; + secno to[n_spares]; + + The to[] list is initialized to point to n_spares preallocated empty + sectors. The from[] list contains the sector numbers of bad blocks + which have been remapped to corresponding sectors in the to[] list. + n_spares_used gives the length of the from[] list. */ + + +/* Sectors 18 and 19 are preallocated and unused. + Maybe they're spares for 16 and 17, but simple substitution fails. */ + + +/* The code page info pointed to by the spare block consists of an index + block and blocks containing uppercasing tables. I don't know what + these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them + itself. Linux doesn't use them either. */ + +/* block pointed to by spareblock->code_page_dir */ + +#define CP_DIR_MAGIC 0x494521f7 + +struct code_page_directory +{ + __le32 magic; /* 4945 21f7 */ + __le32 n_code_pages; /* number of pointers following */ + __le32 zero1[2]; + struct { + __le16 ix; /* index */ + __le16 code_page_number; /* code page number */ + __le32 bounds; /* matches corresponding word + in data block */ + __le32 code_page_data; /* sector number of a code_page_data + containing c.p. array */ + __le16 index; /* index in c.p. array in that sector*/ + __le16 unknown; /* some unknown value; usually 0; + 2 in Japanese version */ + } array[31]; /* unknown length */ +}; + +/* blocks pointed to by code_page_directory */ + +#define CP_DATA_MAGIC 0x894521f7 + +struct code_page_data +{ + __le32 magic; /* 8945 21f7 */ + __le32 n_used; /* # elements used in c_p_data[] */ + __le32 bounds[3]; /* looks a bit like + (beg1,end1), (beg2,end2) + one byte each */ + __le16 offs[3]; /* offsets from start of sector + to start of c_p_data[ix] */ + struct { + __le16 ix; /* index */ + __le16 code_page_number; /* code page number */ + __le16 unknown; /* the same as in cp directory */ + u8 map[128]; /* upcase table for chars 80..ff */ + __le16 zero2; + } code_page[3]; + u8 incognita[78]; +}; + + +/* Free space bitmaps are 4 sectors long, which is 16384 bits. + 16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap. + Bit order in the maps is little-endian. 0 means taken, 1 means free. + + Bit map sectors are marked allocated in the bit maps, and so are sectors + off the end of the partition. + + Band 0 is sectors 0-3fff, its map is in sectors 18-1b. + Band 1 is 4000-7fff, its map is in 7ffc-7fff. + Band 2 is 8000-ffff, its map is in 8000-8003. + The remaining bands have maps in their first (even) or last (odd) 4 sectors + -- if the last, partial, band is odd its map is in its last 4 sectors. + + The bitmap locations are given in a table pointed to by the super block. + No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is + just where they usually are. + + The "directory band" is a bunch of sectors preallocated for dnodes. + It has a 4-sector free space bitmap of its own. Each bit in the map + corresponds to one 4-sector dnode, bit 0 of the map corresponding to + the first 4 sectors of the directory band. The entire band is marked + allocated in the main bitmap. The super block gives the locations + of the directory band and its bitmap. ("band" doesn't mean it is + 8 meg long; it isn't.) */ + + +/* dnode: directory. 4 sectors long */ + +/* A directory is a tree of dnodes. The fnode for a directory + contains one pointer, to the root dnode of the tree. The fnode + never moves, the dnodes do the B-tree thing, splitting and merging + as files are added and removed. */ + +#define DNODE_MAGIC 0x77e40aae + +struct dnode { + __le32 magic; /* 77e4 0aae */ + __le32 first_free; /* offset from start of dnode to + first free dir entry */ +#ifdef __LITTLE_ENDIAN + u8 root_dnode: 1; /* Is it root dnode? */ + u8 increment_me: 7; /* some kind of activity counter? */ + /* Neither HPFS.IFS nor CHKDSK cares + if you change this word */ +#else + u8 increment_me: 7; /* some kind of activity counter? */ + /* Neither HPFS.IFS nor CHKDSK cares + if you change this word */ + u8 root_dnode: 1; /* Is it root dnode? */ +#endif + u8 increment_me2[3]; + __le32 up; /* (root dnode) directory's fnode + (nonroot) parent dnode */ + __le32 self; /* pointer to this dnode */ + u8 dirent[2028]; /* one or more dirents */ +}; + +struct hpfs_dirent { + __le16 length; /* offset to next dirent */ + +#ifdef __LITTLE_ENDIAN + u8 first: 1; /* set on phony ^A^A (".") entry */ + u8 has_acl: 1; + u8 down: 1; /* down pointer present (after name) */ + u8 last: 1; /* set on phony \377 entry */ + u8 has_ea: 1; /* entry has EA */ + u8 has_xtd_perm: 1; /* has extended perm list (???) */ + u8 has_explicit_acl: 1; + u8 has_needea: 1; /* ?? some EA has NEEDEA set + I have no idea why this is + interesting in a dir entry */ +#else + u8 has_needea: 1; /* ?? some EA has NEEDEA set + I have no idea why this is + interesting in a dir entry */ + u8 has_explicit_acl: 1; + u8 has_xtd_perm: 1; /* has extended perm list (???) */ + u8 has_ea: 1; /* entry has EA */ + u8 last: 1; /* set on phony \377 entry */ + u8 down: 1; /* down pointer present (after name) */ + u8 has_acl: 1; + u8 first: 1; /* set on phony ^A^A (".") entry */ +#endif + +#ifdef __LITTLE_ENDIAN + u8 read_only: 1; /* dos attrib */ + u8 hidden: 1; /* dos attrib */ + u8 system: 1; /* dos attrib */ + u8 flag11: 1; /* would be volume label dos attrib */ + u8 directory: 1; /* dos attrib */ + u8 archive: 1; /* dos attrib */ + u8 not_8x3: 1; /* name is not 8.3 */ + u8 flag15: 1; +#else + u8 flag15: 1; + u8 not_8x3: 1; /* name is not 8.3 */ + u8 archive: 1; /* dos attrib */ + u8 directory: 1; /* dos attrib */ + u8 flag11: 1; /* would be volume label dos attrib */ + u8 system: 1; /* dos attrib */ + u8 hidden: 1; /* dos attrib */ + u8 read_only: 1; /* dos attrib */ +#endif + + __le32 fnode; /* fnode giving allocation info */ + __le32 write_date; /* mtime */ + __le32 file_size; /* file length, bytes */ + __le32 read_date; /* atime */ + __le32 creation_date; /* ctime */ + __le32 ea_size; /* total EA length, bytes */ + u8 no_of_acls; /* number of ACL's (low 3 bits) */ + u8 ix; /* code page index (of filename), see + struct code_page_data */ + u8 namelen, name[1]; /* file name */ + /* dnode_secno down; btree down pointer, if present, + follows name on next word boundary, or maybe it + precedes next dirent, which is on a word boundary. */ +}; + + +/* B+ tree: allocation info in fnodes and anodes */ + +/* dnodes point to fnodes which are responsible for listing the sectors + assigned to the file. This is done with trees of (length,address) + pairs. (Actually triples, of (length, file-address, disk-address) + which can represent holes. Find out if HPFS does that.) + At any rate, fnodes contain a small tree; if subtrees are needed + they occupy essentially a full block in anodes. A leaf-level tree node + has 3-word entries giving sector runs, a non-leaf node has 2-word + entries giving subtree pointers. A flag in the header says which. */ + +struct bplus_leaf_node +{ + __le32 file_secno; /* first file sector in extent */ + __le32 length; /* length, sectors */ + __le32 disk_secno; /* first corresponding disk sector */ +}; + +struct bplus_internal_node +{ + __le32 file_secno; /* subtree maps sectors < this */ + __le32 down; /* pointer to subtree */ +}; + +enum { + BP_hbff = 1, + BP_fnode_parent = 0x20, + BP_binary_search = 0x40, + BP_internal = 0x80 +}; +struct bplus_header +{ + u8 flags; /* bit 0 - high bit of first free entry offset + bit 5 - we're pointed to by an fnode, + the data btree or some ea or the + main ea bootage pointer ea_secno + bit 6 - suggest binary search (unused) + bit 7 - 1 -> (internal) tree of anodes + 0 -> (leaf) list of extents */ + u8 fill[3]; + u8 n_free_nodes; /* free nodes in following array */ + u8 n_used_nodes; /* used nodes in following array */ + __le16 first_free; /* offset from start of header to + first free node in array */ + union { + struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving + subtree pointers */ + struct bplus_leaf_node external[0]; /* (external) 3-word entries giving + sector runs */ + } u; +}; + +static inline bool bp_internal(struct bplus_header *bp) +{ + return bp->flags & BP_internal; +} + +static inline bool bp_fnode_parent(struct bplus_header *bp) +{ + return bp->flags & BP_fnode_parent; +} + +/* fnode: root of allocation b+ tree, and EA's */ + +/* Every file and every directory has one fnode, pointed to by the directory + entry and pointing to the file's sectors or directory's root dnode. EA's + are also stored here, and there are said to be ACL's somewhere here too. */ + +#define FNODE_MAGIC 0xf7e40aae + +enum {FNODE_anode = cpu_to_le16(2), FNODE_dir = cpu_to_le16(256)}; +struct fnode +{ + __le32 magic; /* f7e4 0aae */ + __le32 zero1[2]; /* read history */ + u8 len, name[15]; /* true length, truncated name */ + __le32 up; /* pointer to file's directory fnode */ + __le32 acl_size_l; + __le32 acl_secno; + __le16 acl_size_s; + u8 acl_anode; + u8 zero2; /* history bit count */ + __le32 ea_size_l; /* length of disk-resident ea's */ + __le32 ea_secno; /* first sector of disk-resident ea's*/ + __le16 ea_size_s; /* length of fnode-resident ea's */ + + __le16 flags; /* bit 1 set -> ea_secno is an anode */ + /* bit 8 set -> directory. first & only extent + points to dnode. */ + struct bplus_header btree; /* b+ tree, 8 extents or 12 subtrees */ + union { + struct bplus_leaf_node external[8]; + struct bplus_internal_node internal[12]; + } u; + + __le32 file_size; /* file length, bytes */ + __le32 n_needea; /* number of EA's with NEEDEA set */ + u8 user_id[16]; /* unused */ + __le16 ea_offs; /* offset from start of fnode + to first fnode-resident ea */ + u8 dasd_limit_treshhold; + u8 dasd_limit_delta; + __le32 dasd_limit; + __le32 dasd_usage; + u8 ea[316]; /* zero or more EA's, packed together + with no alignment padding. + (Do not use this name, get here + via fnode + ea_offs. I think.) */ +}; + +static inline bool fnode_in_anode(struct fnode *p) +{ + return (p->flags & FNODE_anode) != 0; +} + +static inline bool fnode_is_dir(struct fnode *p) +{ + return (p->flags & FNODE_dir) != 0; +} + + +/* anode: 99.44% pure allocation tree */ + +#define ANODE_MAGIC 0x37e40aae + +struct anode +{ + __le32 magic; /* 37e4 0aae */ + __le32 self; /* pointer to this anode */ + __le32 up; /* parent anode or fnode */ + + struct bplus_header btree; /* b+tree, 40 extents or 60 subtrees */ + union { + struct bplus_leaf_node external[40]; + struct bplus_internal_node internal[60]; + } u; + + __le32 fill[3]; /* unused */ +}; + + +/* extended attributes. + + A file's EA info is stored as a list of (name,value) pairs. It is + usually in the fnode, but (if it's large) it is moved to a single + sector run outside the fnode, or to multiple runs with an anode tree + that points to them. + + The value of a single EA is stored along with the name, or (if large) + it is moved to a single sector run, or multiple runs pointed to by an + anode tree, pointed to by the value field of the (name,value) pair. + + Flags in the EA tell whether the value is immediate, in a single sector + run, or in multiple runs. Flags in the fnode tell whether the EA list + is immediate, in a single run, or in multiple runs. */ + +enum {EA_indirect = 1, EA_anode = 2, EA_needea = 128 }; +struct extended_attribute +{ + u8 flags; /* bit 0 set -> value gives sector number + where real value starts */ + /* bit 1 set -> sector is an anode + that points to fragmented value */ + /* bit 7 set -> required ea */ + u8 namelen; /* length of name, bytes */ + u8 valuelen_lo; /* length of value, bytes */ + u8 valuelen_hi; /* length of value, bytes */ + u8 name[]; + /* + u8 name[namelen]; ascii attrib name + u8 nul; terminating '\0', not counted + u8 value[valuelen]; value, arbitrary + if this.flags & 1, valuelen is 8 and the value is + u32 length; real length of value, bytes + secno secno; sector address where it starts + if this.anode, the above sector number is the root of an anode tree + which points to the value. + */ +}; + +static inline bool ea_indirect(struct extended_attribute *ea) +{ + return ea->flags & EA_indirect; +} + +static inline bool ea_in_anode(struct extended_attribute *ea) +{ + return ea->flags & EA_anode; +} + +/* + Local Variables: + comment-column: 40 + End: +*/ |