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cb1d150d80
Trivial fix to spelling mistakes in comments Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
560 lines
18 KiB
C
560 lines
18 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* linux/fs/hpfs/hpfs.h
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*
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* HPFS structures by Chris Smith, 1993
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*
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* a little bit modified by Mikulas Patocka, 1998-1999
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*/
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/* The paper
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Duncan, Roy
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Design goals and implementation of the new High Performance File System
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Microsoft Systems Journal Sept 1989 v4 n5 p1(13)
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describes what HPFS looked like when it was new, and it is the source
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of most of the information given here. The rest is conjecture.
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For definitive information on the Duncan paper, see it, not this file.
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For definitive information on HPFS, ask somebody else -- this is guesswork.
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There are certain to be many mistakes. */
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#if !defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
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#error unknown endian
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#endif
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/* Notation */
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typedef u32 secno; /* sector number, partition relative */
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typedef secno dnode_secno; /* sector number of a dnode */
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typedef secno fnode_secno; /* sector number of an fnode */
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typedef secno anode_secno; /* sector number of an anode */
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typedef u32 time32_t; /* 32-bit time_t type */
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/* sector 0 */
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/* The boot block is very like a FAT boot block, except that the
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29h signature byte is 28h instead, and the ID string is "HPFS". */
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#define BB_MAGIC 0xaa55
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struct hpfs_boot_block
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{
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u8 jmp[3];
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u8 oem_id[8];
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u8 bytes_per_sector[2]; /* 512 */
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u8 sectors_per_cluster;
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u8 n_reserved_sectors[2];
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u8 n_fats;
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u8 n_rootdir_entries[2];
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u8 n_sectors_s[2];
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u8 media_byte;
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__le16 sectors_per_fat;
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__le16 sectors_per_track;
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__le16 heads_per_cyl;
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__le32 n_hidden_sectors;
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__le32 n_sectors_l; /* size of partition */
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u8 drive_number;
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u8 mbz;
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u8 sig_28h; /* 28h */
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u8 vol_serno[4];
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u8 vol_label[11];
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u8 sig_hpfs[8]; /* "HPFS " */
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u8 pad[448];
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__le16 magic; /* aa55 */
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};
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/* sector 16 */
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/* The super block has the pointer to the root directory. */
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#define SB_MAGIC 0xf995e849
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struct hpfs_super_block
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{
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__le32 magic; /* f995 e849 */
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__le32 magic1; /* fa53 e9c5, more magic? */
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u8 version; /* version of a filesystem usually 2 */
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u8 funcversion; /* functional version - oldest version
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of filesystem that can understand
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this disk */
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__le16 zero; /* 0 */
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__le32 root; /* fnode of root directory */
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__le32 n_sectors; /* size of filesystem */
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__le32 n_badblocks; /* number of bad blocks */
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__le32 bitmaps; /* pointers to free space bit maps */
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__le32 zero1; /* 0 */
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__le32 badblocks; /* bad block list */
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__le32 zero3; /* 0 */
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__le32 last_chkdsk; /* date last checked, 0 if never */
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__le32 last_optimize; /* date last optimized, 0 if never */
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__le32 n_dir_band; /* number of sectors in dir band */
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__le32 dir_band_start; /* first sector in dir band */
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__le32 dir_band_end; /* last sector in dir band */
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__le32 dir_band_bitmap; /* free space map, 1 dnode per bit */
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u8 volume_name[32]; /* not used */
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__le32 user_id_table; /* 8 preallocated sectors - user id */
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u32 zero6[103]; /* 0 */
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};
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/* sector 17 */
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/* The spare block has pointers to spare sectors. */
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#define SP_MAGIC 0xf9911849
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struct hpfs_spare_block
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{
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__le32 magic; /* f991 1849 */
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__le32 magic1; /* fa52 29c5, more magic? */
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#ifdef __LITTLE_ENDIAN
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u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
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u8 sparedir_used: 1; /* spare dirblks used */
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u8 hotfixes_used: 1; /* hotfixes used */
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u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
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u8 bad_bitmap: 1; /* bad bitmap */
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u8 fast: 1; /* partition was fast formatted */
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u8 old_wrote: 1; /* old version wrote to partition */
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u8 old_wrote_1: 1; /* old version wrote to partition (?) */
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#else
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u8 old_wrote_1: 1; /* old version wrote to partition (?) */
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u8 old_wrote: 1; /* old version wrote to partition */
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u8 fast: 1; /* partition was fast formatted */
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u8 bad_bitmap: 1; /* bad bitmap */
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u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
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u8 hotfixes_used: 1; /* hotfixes used */
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u8 sparedir_used: 1; /* spare dirblks used */
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u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
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#endif
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#ifdef __LITTLE_ENDIAN
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u8 install_dasd_limits: 1; /* HPFS386 flags */
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u8 resynch_dasd_limits: 1;
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u8 dasd_limits_operational: 1;
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u8 multimedia_active: 1;
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u8 dce_acls_active: 1;
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u8 dasd_limits_dirty: 1;
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u8 flag67: 2;
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#else
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u8 flag67: 2;
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u8 dasd_limits_dirty: 1;
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u8 dce_acls_active: 1;
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u8 multimedia_active: 1;
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u8 dasd_limits_operational: 1;
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u8 resynch_dasd_limits: 1;
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u8 install_dasd_limits: 1; /* HPFS386 flags */
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#endif
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u8 mm_contlgulty;
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u8 unused;
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__le32 hotfix_map; /* info about remapped bad sectors */
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__le32 n_spares_used; /* number of hotfixes */
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__le32 n_spares; /* number of spares in hotfix map */
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__le32 n_dnode_spares_free; /* spare dnodes unused */
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__le32 n_dnode_spares; /* length of spare_dnodes[] list,
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follows in this block*/
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__le32 code_page_dir; /* code page directory block */
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__le32 n_code_pages; /* number of code pages */
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__le32 super_crc; /* on HPFS386 and LAN Server this is
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checksum of superblock, on normal
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OS/2 unused */
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__le32 spare_crc; /* on HPFS386 checksum of spareblock */
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__le32 zero1[15]; /* unused */
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__le32 spare_dnodes[100]; /* emergency free dnode list */
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__le32 zero2[1]; /* room for more? */
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};
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/* The bad block list is 4 sectors long. The first word must be zero,
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the remaining words give n_badblocks bad block numbers.
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I bet you can see it coming... */
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#define BAD_MAGIC 0
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/* The hotfix map is 4 sectors long. It looks like
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secno from[n_spares];
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secno to[n_spares];
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The to[] list is initialized to point to n_spares preallocated empty
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sectors. The from[] list contains the sector numbers of bad blocks
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which have been remapped to corresponding sectors in the to[] list.
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n_spares_used gives the length of the from[] list. */
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/* Sectors 18 and 19 are preallocated and unused.
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Maybe they're spares for 16 and 17, but simple substitution fails. */
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/* The code page info pointed to by the spare block consists of an index
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block and blocks containing uppercasing tables. I don't know what
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these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them
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itself. Linux doesn't use them either. */
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/* block pointed to by spareblock->code_page_dir */
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#define CP_DIR_MAGIC 0x494521f7
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struct code_page_directory
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{
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__le32 magic; /* 4945 21f7 */
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__le32 n_code_pages; /* number of pointers following */
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__le32 zero1[2];
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struct {
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__le16 ix; /* index */
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__le16 code_page_number; /* code page number */
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__le32 bounds; /* matches corresponding word
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in data block */
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__le32 code_page_data; /* sector number of a code_page_data
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containing c.p. array */
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__le16 index; /* index in c.p. array in that sector*/
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__le16 unknown; /* some unknown value; usually 0;
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2 in Japanese version */
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} array[31]; /* unknown length */
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};
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/* blocks pointed to by code_page_directory */
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#define CP_DATA_MAGIC 0x894521f7
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struct code_page_data
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{
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__le32 magic; /* 8945 21f7 */
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__le32 n_used; /* # elements used in c_p_data[] */
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__le32 bounds[3]; /* looks a bit like
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(beg1,end1), (beg2,end2)
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one byte each */
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__le16 offs[3]; /* offsets from start of sector
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to start of c_p_data[ix] */
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struct {
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__le16 ix; /* index */
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__le16 code_page_number; /* code page number */
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__le16 unknown; /* the same as in cp directory */
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u8 map[128]; /* upcase table for chars 80..ff */
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__le16 zero2;
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} code_page[3];
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u8 incognita[78];
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};
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/* Free space bitmaps are 4 sectors long, which is 16384 bits.
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16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap.
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Bit order in the maps is little-endian. 0 means taken, 1 means free.
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Bit map sectors are marked allocated in the bit maps, and so are sectors
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off the end of the partition.
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Band 0 is sectors 0-3fff, its map is in sectors 18-1b.
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Band 1 is 4000-7fff, its map is in 7ffc-7fff.
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Band 2 is 8000-ffff, its map is in 8000-8003.
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The remaining bands have maps in their first (even) or last (odd) 4 sectors
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-- if the last, partial, band is odd its map is in its last 4 sectors.
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The bitmap locations are given in a table pointed to by the super block.
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No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is
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just where they usually are.
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The "directory band" is a bunch of sectors preallocated for dnodes.
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It has a 4-sector free space bitmap of its own. Each bit in the map
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corresponds to one 4-sector dnode, bit 0 of the map corresponding to
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the first 4 sectors of the directory band. The entire band is marked
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allocated in the main bitmap. The super block gives the locations
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of the directory band and its bitmap. ("band" doesn't mean it is
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8 meg long; it isn't.) */
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/* dnode: directory. 4 sectors long */
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/* A directory is a tree of dnodes. The fnode for a directory
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contains one pointer, to the root dnode of the tree. The fnode
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never moves, the dnodes do the B-tree thing, splitting and merging
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as files are added and removed. */
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#define DNODE_MAGIC 0x77e40aae
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struct dnode {
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__le32 magic; /* 77e4 0aae */
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__le32 first_free; /* offset from start of dnode to
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first free dir entry */
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#ifdef __LITTLE_ENDIAN
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u8 root_dnode: 1; /* Is it root dnode? */
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u8 increment_me: 7; /* some kind of activity counter? */
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/* Neither HPFS.IFS nor CHKDSK cares
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if you change this word */
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#else
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u8 increment_me: 7; /* some kind of activity counter? */
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/* Neither HPFS.IFS nor CHKDSK cares
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if you change this word */
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u8 root_dnode: 1; /* Is it root dnode? */
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#endif
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u8 increment_me2[3];
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__le32 up; /* (root dnode) directory's fnode
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(nonroot) parent dnode */
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__le32 self; /* pointer to this dnode */
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u8 dirent[2028]; /* one or more dirents */
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};
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struct hpfs_dirent {
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__le16 length; /* offset to next dirent */
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#ifdef __LITTLE_ENDIAN
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u8 first: 1; /* set on phony ^A^A (".") entry */
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u8 has_acl: 1;
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u8 down: 1; /* down pointer present (after name) */
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u8 last: 1; /* set on phony \377 entry */
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u8 has_ea: 1; /* entry has EA */
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u8 has_xtd_perm: 1; /* has extended perm list (???) */
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u8 has_explicit_acl: 1;
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u8 has_needea: 1; /* ?? some EA has NEEDEA set
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I have no idea why this is
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interesting in a dir entry */
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#else
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u8 has_needea: 1; /* ?? some EA has NEEDEA set
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I have no idea why this is
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interesting in a dir entry */
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u8 has_explicit_acl: 1;
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u8 has_xtd_perm: 1; /* has extended perm list (???) */
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u8 has_ea: 1; /* entry has EA */
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u8 last: 1; /* set on phony \377 entry */
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u8 down: 1; /* down pointer present (after name) */
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u8 has_acl: 1;
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u8 first: 1; /* set on phony ^A^A (".") entry */
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#endif
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#ifdef __LITTLE_ENDIAN
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u8 read_only: 1; /* dos attrib */
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u8 hidden: 1; /* dos attrib */
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u8 system: 1; /* dos attrib */
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u8 flag11: 1; /* would be volume label dos attrib */
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u8 directory: 1; /* dos attrib */
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u8 archive: 1; /* dos attrib */
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u8 not_8x3: 1; /* name is not 8.3 */
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u8 flag15: 1;
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#else
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u8 flag15: 1;
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u8 not_8x3: 1; /* name is not 8.3 */
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u8 archive: 1; /* dos attrib */
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u8 directory: 1; /* dos attrib */
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u8 flag11: 1; /* would be volume label dos attrib */
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u8 system: 1; /* dos attrib */
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u8 hidden: 1; /* dos attrib */
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u8 read_only: 1; /* dos attrib */
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#endif
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__le32 fnode; /* fnode giving allocation info */
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__le32 write_date; /* mtime */
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__le32 file_size; /* file length, bytes */
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__le32 read_date; /* atime */
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__le32 creation_date; /* ctime */
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__le32 ea_size; /* total EA length, bytes */
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u8 no_of_acls; /* number of ACL's (low 3 bits) */
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u8 ix; /* code page index (of filename), see
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struct code_page_data */
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u8 namelen, name[1]; /* file name */
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/* dnode_secno down; btree down pointer, if present,
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follows name on next word boundary, or maybe it
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precedes next dirent, which is on a word boundary. */
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};
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/* B+ tree: allocation info in fnodes and anodes */
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/* dnodes point to fnodes which are responsible for listing the sectors
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assigned to the file. This is done with trees of (length,address)
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pairs. (Actually triples, of (length, file-address, disk-address)
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which can represent holes. Find out if HPFS does that.)
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At any rate, fnodes contain a small tree; if subtrees are needed
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they occupy essentially a full block in anodes. A leaf-level tree node
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has 3-word entries giving sector runs, a non-leaf node has 2-word
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entries giving subtree pointers. A flag in the header says which. */
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struct bplus_leaf_node
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{
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__le32 file_secno; /* first file sector in extent */
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__le32 length; /* length, sectors */
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__le32 disk_secno; /* first corresponding disk sector */
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};
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struct bplus_internal_node
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{
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__le32 file_secno; /* subtree maps sectors < this */
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__le32 down; /* pointer to subtree */
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};
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enum {
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BP_hbff = 1,
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BP_fnode_parent = 0x20,
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BP_binary_search = 0x40,
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BP_internal = 0x80
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};
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struct bplus_header
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{
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u8 flags; /* bit 0 - high bit of first free entry offset
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bit 5 - we're pointed to by an fnode,
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the data btree or some ea or the
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main ea bootage pointer ea_secno
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bit 6 - suggest binary search (unused)
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bit 7 - 1 -> (internal) tree of anodes
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0 -> (leaf) list of extents */
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u8 fill[3];
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u8 n_free_nodes; /* free nodes in following array */
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u8 n_used_nodes; /* used nodes in following array */
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__le16 first_free; /* offset from start of header to
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first free node in array */
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union {
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struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
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subtree pointers */
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struct bplus_leaf_node external[0]; /* (external) 3-word entries giving
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sector runs */
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} u;
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};
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static inline bool bp_internal(struct bplus_header *bp)
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{
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return bp->flags & BP_internal;
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}
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static inline bool bp_fnode_parent(struct bplus_header *bp)
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{
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return bp->flags & BP_fnode_parent;
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}
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/* fnode: root of allocation b+ tree, and EA's */
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/* Every file and every directory has one fnode, pointed to by the directory
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entry and pointing to the file's sectors or directory's root dnode. EA's
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are also stored here, and there are said to be ACL's somewhere here too. */
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#define FNODE_MAGIC 0xf7e40aae
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enum {FNODE_anode = cpu_to_le16(2), FNODE_dir = cpu_to_le16(256)};
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struct fnode
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{
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__le32 magic; /* f7e4 0aae */
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__le32 zero1[2]; /* read history */
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u8 len, name[15]; /* true length, truncated name */
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__le32 up; /* pointer to file's directory fnode */
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__le32 acl_size_l;
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__le32 acl_secno;
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__le16 acl_size_s;
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u8 acl_anode;
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u8 zero2; /* history bit count */
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__le32 ea_size_l; /* length of disk-resident ea's */
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__le32 ea_secno; /* first sector of disk-resident ea's*/
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__le16 ea_size_s; /* length of fnode-resident ea's */
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__le16 flags; /* bit 1 set -> ea_secno is an anode */
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/* bit 8 set -> directory. first & only extent
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points to dnode. */
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struct bplus_header btree; /* b+ tree, 8 extents or 12 subtrees */
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union {
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struct bplus_leaf_node external[8];
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struct bplus_internal_node internal[12];
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} u;
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__le32 file_size; /* file length, bytes */
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__le32 n_needea; /* number of EA's with NEEDEA set */
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u8 user_id[16]; /* unused */
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__le16 ea_offs; /* offset from start of fnode
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to first fnode-resident ea */
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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:
|
|
*/
|