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+/*
+ * 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. */
+
+/* Notation */
+
+typedef unsigned 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
+{
+ unsigned char jmp[3];
+ unsigned char oem_id[8];
+ unsigned char bytes_per_sector[2]; /* 512 */
+ unsigned char sectors_per_cluster;
+ unsigned char n_reserved_sectors[2];
+ unsigned char n_fats;
+ unsigned char n_rootdir_entries[2];
+ unsigned char n_sectors_s[2];
+ unsigned char media_byte;
+ unsigned short sectors_per_fat;
+ unsigned short sectors_per_track;
+ unsigned short heads_per_cyl;
+ unsigned int n_hidden_sectors;
+ unsigned int n_sectors_l; /* size of partition */
+ unsigned char drive_number;
+ unsigned char mbz;
+ unsigned char sig_28h; /* 28h */
+ unsigned char vol_serno[4];
+ unsigned char vol_label[11];
+ unsigned char sig_hpfs[8]; /* "HPFS " */
+ unsigned char pad[448];
+ unsigned short magic; /* aa55 */
+};
+
+
+/* sector 16 */
+
+/* The super block has the pointer to the root directory. */
+
+#define SB_MAGIC 0xf995e849
+
+struct hpfs_super_block
+{
+ unsigned magic; /* f995 e849 */
+ unsigned magic1; /* fa53 e9c5, more magic? */
+ /*unsigned huh202;*/ /* ?? 202 = N. of B. in 1.00390625 S.*/
+ char version; /* version of a filesystem usually 2 */
+ char funcversion; /* functional version - oldest version
+ of filesystem that can understand
+ this disk */
+ unsigned short int zero; /* 0 */
+ fnode_secno root; /* fnode of root directory */
+ secno n_sectors; /* size of filesystem */
+ unsigned n_badblocks; /* number of bad blocks */
+ secno bitmaps; /* pointers to free space bit maps */
+ unsigned zero1; /* 0 */
+ secno badblocks; /* bad block list */
+ unsigned zero3; /* 0 */
+ time32_t last_chkdsk; /* date last checked, 0 if never */
+ /*unsigned zero4;*/ /* 0 */
+ time32_t last_optimize; /* date last optimized, 0 if never */
+ secno n_dir_band; /* number of sectors in dir band */
+ secno dir_band_start; /* first sector in dir band */
+ secno dir_band_end; /* last sector in dir band */
+ secno dir_band_bitmap; /* free space map, 1 dnode per bit */
+ char volume_name[32]; /* not used */
+ secno user_id_table; /* 8 preallocated sectors - user id */
+ unsigned zero6[103]; /* 0 */
+};
+
+
+/* sector 17 */
+
+/* The spare block has pointers to spare sectors. */
+
+#define SP_MAGIC 0xf9911849
+
+struct hpfs_spare_block
+{
+ unsigned magic; /* f991 1849 */
+ unsigned magic1; /* fa52 29c5, more magic? */
+
+ unsigned dirty: 1; /* 0 clean, 1 "improperly stopped" */
+ /*unsigned flag1234: 4;*/ /* unknown flags */
+ unsigned sparedir_used: 1; /* spare dirblks used */
+ unsigned hotfixes_used: 1; /* hotfixes used */
+ unsigned bad_sector: 1; /* bad sector, corrupted disk (???) */
+ unsigned bad_bitmap: 1; /* bad bitmap */
+ unsigned fast: 1; /* partition was fast formatted */
+ unsigned old_wrote: 1; /* old version wrote to partion */
+ unsigned old_wrote_1: 1; /* old version wrote to partion (?) */
+ unsigned install_dasd_limits: 1; /* HPFS386 flags */
+ unsigned resynch_dasd_limits: 1;
+ unsigned dasd_limits_operational: 1;
+ unsigned multimedia_active: 1;
+ unsigned dce_acls_active: 1;
+ unsigned dasd_limits_dirty: 1;
+ unsigned flag67: 2;
+ unsigned char mm_contlgulty;
+ unsigned char unused;
+
+ secno hotfix_map; /* info about remapped bad sectors */
+ unsigned n_spares_used; /* number of hotfixes */
+ unsigned n_spares; /* number of spares in hotfix map */
+ unsigned n_dnode_spares_free; /* spare dnodes unused */
+ unsigned n_dnode_spares; /* length of spare_dnodes[] list,
+ follows in this block*/
+ secno code_page_dir; /* code page directory block */
+ unsigned n_code_pages; /* number of code pages */
+ /*unsigned large_numbers[2];*/ /* ?? */
+ unsigned super_crc; /* on HPFS386 and LAN Server this is
+ checksum of superblock, on normal
+ OS/2 unused */
+ unsigned spare_crc; /* on HPFS386 checksum of spareblock */
+ unsigned zero1[15]; /* unused */
+ dnode_secno spare_dnodes[100]; /* emergency free dnode list */
+ unsigned 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
+{
+ unsigned magic; /* 4945 21f7 */
+ unsigned n_code_pages; /* number of pointers following */
+ unsigned zero1[2];
+ struct {
+ unsigned short ix; /* index */
+ unsigned short code_page_number; /* code page number */
+ unsigned bounds; /* matches corresponding word
+ in data block */
+ secno code_page_data; /* sector number of a code_page_data
+ containing c.p. array */
+ unsigned short index; /* index in c.p. array in that sector*/
+ unsigned short 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
+{
+ unsigned magic; /* 8945 21f7 */
+ unsigned n_used; /* # elements used in c_p_data[] */
+ unsigned bounds[3]; /* looks a bit like
+ (beg1,end1), (beg2,end2)
+ one byte each */
+ unsigned short offs[3]; /* offsets from start of sector
+ to start of c_p_data[ix] */
+ struct {
+ unsigned short ix; /* index */
+ unsigned short code_page_number; /* code page number */
+ unsigned short unknown; /* the same as in cp directory */
+ unsigned char map[128]; /* upcase table for chars 80..ff */
+ unsigned short zero2;
+ } code_page[3];
+ unsigned char 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 {
+ unsigned magic; /* 77e4 0aae */
+ unsigned first_free; /* offset from start of dnode to
+ first free dir entry */
+ unsigned root_dnode:1; /* Is it root dnode? */
+ unsigned increment_me:31; /* some kind of activity counter?
+ Neither HPFS.IFS nor CHKDSK cares
+ if you change this word */
+ secno up; /* (root dnode) directory's fnode
+ (nonroot) parent dnode */
+ dnode_secno self; /* pointer to this dnode */
+ unsigned char dirent[2028]; /* one or more dirents */
+};
+
+struct hpfs_dirent {
+ unsigned short length; /* offset to next dirent */
+ unsigned first: 1; /* set on phony ^A^A (".") entry */
+ unsigned has_acl: 1;
+ unsigned down: 1; /* down pointer present (after name) */
+ unsigned last: 1; /* set on phony \377 entry */
+ unsigned has_ea: 1; /* entry has EA */
+ unsigned has_xtd_perm: 1; /* has extended perm list (???) */
+ unsigned has_explicit_acl: 1;
+ unsigned has_needea: 1; /* ?? some EA has NEEDEA set
+ I have no idea why this is
+ interesting in a dir entry */
+ unsigned read_only: 1; /* dos attrib */
+ unsigned hidden: 1; /* dos attrib */
+ unsigned system: 1; /* dos attrib */
+ unsigned flag11: 1; /* would be volume label dos attrib */
+ unsigned directory: 1; /* dos attrib */
+ unsigned archive: 1; /* dos attrib */
+ unsigned not_8x3: 1; /* name is not 8.3 */
+ unsigned flag15: 1;
+ fnode_secno fnode; /* fnode giving allocation info */
+ time32_t write_date; /* mtime */
+ unsigned file_size; /* file length, bytes */
+ time32_t read_date; /* atime */
+ time32_t creation_date; /* ctime */
+ unsigned ea_size; /* total EA length, bytes */
+ unsigned char no_of_acls : 3; /* number of ACL's */
+ unsigned char reserver : 5;
+ unsigned char ix; /* code page index (of filename), see
+ struct code_page_data */
+ unsigned char 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
+{
+ unsigned file_secno; /* first file sector in extent */
+ unsigned length; /* length, sectors */
+ secno disk_secno; /* first corresponding disk sector */
+};
+
+struct bplus_internal_node
+{
+ unsigned file_secno; /* subtree maps sectors < this */
+ anode_secno down; /* pointer to subtree */
+};
+
+struct bplus_header
+{
+ unsigned hbff: 1; /* high bit of first free entry offset */
+ unsigned flag1: 1;
+ unsigned flag2: 1;
+ unsigned flag3: 1;
+ unsigned flag4: 1;
+ unsigned fnode_parent: 1; /* ? we're pointed to by an fnode,
+ the data btree or some ea or the
+ main ea bootage pointer ea_secno */
+ /* also can get set in fnodes, which
+ may be a chkdsk glitch or may mean
+ this bit is irrelevant in fnodes,
+ or this interpretation is all wet */
+ unsigned binary_search: 1; /* suggest binary search (unused) */
+ unsigned internal: 1; /* 1 -> (internal) tree of anodes
+ 0 -> (leaf) list of extents */
+ unsigned char fill[3];
+ unsigned char n_free_nodes; /* free nodes in following array */
+ unsigned char n_used_nodes; /* used nodes in following array */
+ unsigned short 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;
+};
+
+/* 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
+
+struct fnode
+{
+ unsigned magic; /* f7e4 0aae */
+ unsigned zero1[2]; /* read history */
+ unsigned char len, name[15]; /* true length, truncated name */
+ fnode_secno up; /* pointer to file's directory fnode */
+ /*unsigned zero2[3];*/
+ secno acl_size_l;
+ secno acl_secno;
+ unsigned short acl_size_s;
+ char acl_anode;
+ char zero2; /* history bit count */
+ unsigned ea_size_l; /* length of disk-resident ea's */
+ secno ea_secno; /* first sector of disk-resident ea's*/
+ unsigned short ea_size_s; /* length of fnode-resident ea's */
+
+ unsigned flag0: 1;
+ unsigned ea_anode: 1; /* 1 -> ea_secno is an anode */
+ unsigned flag2: 1;
+ unsigned flag3: 1;
+ unsigned flag4: 1;
+ unsigned flag5: 1;
+ unsigned flag6: 1;
+ unsigned flag7: 1;
+ unsigned dirflag: 1; /* 1 -> directory. first & only extent
+ points to dnode. */
+ unsigned flag9: 1;
+ unsigned flag10: 1;
+ unsigned flag11: 1;
+ unsigned flag12: 1;
+ unsigned flag13: 1;
+ unsigned flag14: 1;
+ unsigned flag15: 1;
+
+ 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;
+
+ unsigned file_size; /* file length, bytes */
+ unsigned n_needea; /* number of EA's with NEEDEA set */
+ char user_id[16]; /* unused */
+ unsigned short ea_offs; /* offset from start of fnode
+ to first fnode-resident ea */
+ char dasd_limit_treshhold;
+ char dasd_limit_delta;
+ unsigned dasd_limit;
+ unsigned dasd_usage;
+ /*unsigned zero5[2];*/
+ unsigned char 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.) */
+};
+
+
+/* anode: 99.44% pure allocation tree */
+
+#define ANODE_MAGIC 0x37e40aae
+
+struct anode
+{
+ unsigned magic; /* 37e4 0aae */
+ anode_secno self; /* pointer to this anode */
+ secno 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;
+
+ unsigned 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. */
+
+struct extended_attribute
+{
+ unsigned indirect: 1; /* 1 -> value gives sector number
+ where real value starts */
+ unsigned anode: 1; /* 1 -> sector is an anode
+ that points to fragmented value */
+ unsigned flag2: 1;
+ unsigned flag3: 1;
+ unsigned flag4: 1;
+ unsigned flag5: 1;
+ unsigned flag6: 1;
+ unsigned needea: 1; /* required ea */
+ unsigned char namelen; /* length of name, bytes */
+ unsigned short valuelen; /* length of value, bytes */
+ unsigned char name[0];
+ /*
+ unsigned char name[namelen]; ascii attrib name
+ unsigned char nul; terminating '\0', not counted
+ unsigned char value[valuelen]; value, arbitrary
+ if this.indirect, valuelen is 8 and the value is
+ unsigned 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.
+ */
+};
+
+/*
+ Local Variables:
+ comment-column: 40
+ End:
+*/
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