1 /*- 2 * Copyright (c) 1992 Keith Muller. 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Keith Muller of the University of California, San Diego. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tables.h 8.1 (Berkeley) 5/31/93 34 * $FreeBSD: src/bin/pax/tables.h,v 1.7 1999/08/27 23:14:47 peter Exp $ 35 * $DragonFly: src/bin/pax/tables.h,v 1.3 2006/09/27 21:58:08 pavalos Exp $ 36 */ 37 38 /* 39 * data structures and constants used by the different databases kept by pax 40 */ 41 42 /* 43 * Hash Table Sizes MUST BE PRIME, if set too small performance suffers. 44 * Probably safe to expect 500000 inodes per tape. Assuming good key 45 * distribution (inodes) chains of under 50 long (worst case) is ok. 46 */ 47 #define L_TAB_SZ 2503 /* hard link hash table size */ 48 #define F_TAB_SZ 50503 /* file time hash table size */ 49 #define N_TAB_SZ 541 /* interactive rename hash table */ 50 #define D_TAB_SZ 317 /* unique device mapping table */ 51 #define A_TAB_SZ 317 /* ftree dir access time reset table */ 52 #define MAXKEYLEN 64 /* max number of chars for hash */ 53 54 /* 55 * file hard link structure (hashed by dev/ino and chained) used to find the 56 * hard links in a file system or with some archive formats (cpio) 57 */ 58 typedef struct hrdlnk { 59 char *name; /* name of first file seen with this ino/dev */ 60 dev_t dev; /* files device number */ 61 ino_t ino; /* files inode number */ 62 u_long nlink; /* expected link count */ 63 struct hrdlnk *fow; 64 } HRDLNK; 65 66 /* 67 * Archive write update file time table (the -u, -C flag), hashed by filename. 68 * Filenames are stored in a scratch file at seek offset into the file. The 69 * file time (mod time) and the file name length (for a quick check) are 70 * stored in a hash table node. We were forced to use a scratch file because 71 * with -u, the mtime for every node in the archive must always be available 72 * to compare against (and this data can get REALLY large with big archives). 73 * By being careful to read only when we have a good chance of a match, the 74 * performance loss is not measurable (and the size of the archive we can 75 * handle is greatly increased). 76 */ 77 typedef struct ftm { 78 int namelen; /* file name length */ 79 time_t mtime; /* files last modification time */ 80 off_t seek; /* location in scratch file */ 81 struct ftm *fow; 82 } FTM; 83 84 /* 85 * Interactive rename table (-i flag), hashed by orig filename. 86 * We assume this will not be a large table as this mapping data can only be 87 * obtained through interactive input by the user. Nobody is going to type in 88 * changes for 500000 files? We use chaining to resolve collisions. 89 */ 90 91 typedef struct namt { 92 char *oname; /* old name */ 93 char *nname; /* new name typed in by the user */ 94 struct namt *fow; 95 } NAMT; 96 97 /* 98 * Unique device mapping tables. Some protocols (e.g. cpio) require that the 99 * <c_dev,c_ino> pair will uniquely identify a file in an archive unless they 100 * are links to the same file. Appending to archives can break this. For those 101 * protocols that have this requirement we map c_dev to a unique value not seen 102 * in the archive when we append. We also try to handle inode truncation with 103 * this table. (When the inode field in the archive header are too small, we 104 * remap the dev on writes to remove accidental collisions). 105 * 106 * The list is hashed by device number using chain collision resolution. Off of 107 * each DEVT are linked the various remaps for this device based on those bits 108 * in the inode which were truncated. For example if we are just remapping to 109 * avoid a device number during an update append, off the DEVT we would have 110 * only a single DLIST that has a truncation id of 0 (no inode bits were 111 * stripped for this device so far). When we spot inode truncation we create 112 * a new mapping based on the set of bits in the inode which were stripped off. 113 * so if the top four bits of the inode are stripped and they have a pattern of 114 * 0110...... (where . are those bits not truncated) we would have a mapping 115 * assigned for all inodes that has the same 0110.... pattern (with this dev 116 * number of course). This keeps the mapping sparse and should be able to store 117 * close to the limit of files which can be represented by the optimal 118 * combination of dev and inode bits, and without creating a fouled up archive. 119 * Note we also remap truncated devs in the same way (an exercise for the 120 * dedicated reader; always wanted to say that...:) 121 */ 122 123 typedef struct devt { 124 dev_t dev; /* the orig device number we now have to map */ 125 struct devt *fow; /* new device map list */ 126 struct dlist *list; /* map list based on inode truncation bits */ 127 } DEVT; 128 129 typedef struct dlist { 130 ino_t trunc_bits; /* truncation pattern for a specific map */ 131 dev_t dev; /* the new device id we use */ 132 struct dlist *fow; 133 } DLIST; 134 135 /* 136 * ftree directory access time reset table. When we are done with a 137 * subtree we reset the access and mod time of the directory when the tflag is 138 * set. Not really explicitly specified in the pax spec, but easy and fast to 139 * do (and this may have even been intended in the spec, it is not clear). 140 * table is hashed by inode with chaining. 141 */ 142 143 typedef struct atdir { 144 char *name; /* name of directory to reset */ 145 dev_t dev; /* dev and inode for fast lookup */ 146 ino_t ino; 147 time_t mtime; /* access and mod time to reset to */ 148 time_t atime; 149 struct atdir *fow; 150 } ATDIR; 151 152 /* 153 * created directory time and mode storage entry. After pax is finished during 154 * extraction or copy, we must reset directory access modes and times that 155 * may have been modified after creation (they no longer have the specified 156 * times and/or modes). We must reset time in the reverse order of creation, 157 * because entries are added from the top of the file tree to the bottom. 158 * We MUST reset times from leaf to root (it will not work the other 159 * direction). Entries are recorded into a spool file to make reverse 160 * reading faster. 161 */ 162 163 typedef struct dirdata { 164 int nlen; /* length of the directory name (includes \0) */ 165 off_t npos; /* position in file where this dir name starts */ 166 mode_t mode; /* file mode to restore */ 167 time_t mtime; /* mtime to set */ 168 time_t atime; /* atime to set */ 169 int frc_mode; /* do we force mode settings? */ 170 } DIRDATA; 171