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. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)tables.h 8.1 (Berkeley) 5/31/93 38 * $FreeBSD: src/bin/pax/tables.h,v 1.7 1999/08/27 23:14:47 peter Exp $ 39 * $DragonFly: src/bin/pax/tables.h,v 1.3 2006/09/27 21:58:08 pavalos Exp $ 40 */ 41 42 /* 43 * data structures and constants used by the different databases kept by pax 44 */ 45 46 /* 47 * Hash Table Sizes MUST BE PRIME, if set too small performance suffers. 48 * Probably safe to expect 500000 inodes per tape. Assuming good key 49 * distribution (inodes) chains of under 50 long (worst case) is ok. 50 */ 51 #define L_TAB_SZ 2503 /* hard link hash table size */ 52 #define F_TAB_SZ 50503 /* file time hash table size */ 53 #define N_TAB_SZ 541 /* interactive rename hash table */ 54 #define D_TAB_SZ 317 /* unique device mapping table */ 55 #define A_TAB_SZ 317 /* ftree dir access time reset table */ 56 #define MAXKEYLEN 64 /* max number of chars for hash */ 57 58 /* 59 * file hard link structure (hashed by dev/ino and chained) used to find the 60 * hard links in a file system or with some archive formats (cpio) 61 */ 62 typedef struct hrdlnk { 63 char *name; /* name of first file seen with this ino/dev */ 64 dev_t dev; /* files device number */ 65 ino_t ino; /* files inode number */ 66 u_long nlink; /* expected link count */ 67 struct hrdlnk *fow; 68 } HRDLNK; 69 70 /* 71 * Archive write update file time table (the -u, -C flag), hashed by filename. 72 * Filenames are stored in a scratch file at seek offset into the file. The 73 * file time (mod time) and the file name length (for a quick check) are 74 * stored in a hash table node. We were forced to use a scratch file because 75 * with -u, the mtime for every node in the archive must always be available 76 * to compare against (and this data can get REALLY large with big archives). 77 * By being careful to read only when we have a good chance of a match, the 78 * performance loss is not measurable (and the size of the archive we can 79 * handle is greatly increased). 80 */ 81 typedef struct ftm { 82 int namelen; /* file name length */ 83 time_t mtime; /* files last modification time */ 84 off_t seek; /* location in scratch file */ 85 struct ftm *fow; 86 } FTM; 87 88 /* 89 * Interactive rename table (-i flag), hashed by orig filename. 90 * We assume this will not be a large table as this mapping data can only be 91 * obtained through interactive input by the user. Nobody is going to type in 92 * changes for 500000 files? We use chaining to resolve collisions. 93 */ 94 95 typedef struct namt { 96 char *oname; /* old name */ 97 char *nname; /* new name typed in by the user */ 98 struct namt *fow; 99 } NAMT; 100 101 /* 102 * Unique device mapping tables. Some protocols (e.g. cpio) require that the 103 * <c_dev,c_ino> pair will uniquely identify a file in an archive unless they 104 * are links to the same file. Appending to archives can break this. For those 105 * protocols that have this requirement we map c_dev to a unique value not seen 106 * in the archive when we append. We also try to handle inode truncation with 107 * this table. (When the inode field in the archive header are too small, we 108 * remap the dev on writes to remove accidental collisions). 109 * 110 * The list is hashed by device number using chain collision resolution. Off of 111 * each DEVT are linked the various remaps for this device based on those bits 112 * in the inode which were truncated. For example if we are just remapping to 113 * avoid a device number during an update append, off the DEVT we would have 114 * only a single DLIST that has a truncation id of 0 (no inode bits were 115 * stripped for this device so far). When we spot inode truncation we create 116 * a new mapping based on the set of bits in the inode which were stripped off. 117 * so if the top four bits of the inode are stripped and they have a pattern of 118 * 0110...... (where . are those bits not truncated) we would have a mapping 119 * assigned for all inodes that has the same 0110.... pattern (with this dev 120 * number of course). This keeps the mapping sparse and should be able to store 121 * close to the limit of files which can be represented by the optimal 122 * combination of dev and inode bits, and without creating a fouled up archive. 123 * Note we also remap truncated devs in the same way (an exercise for the 124 * dedicated reader; always wanted to say that...:) 125 */ 126 127 typedef struct devt { 128 dev_t dev; /* the orig device number we now have to map */ 129 struct devt *fow; /* new device map list */ 130 struct dlist *list; /* map list based on inode truncation bits */ 131 } DEVT; 132 133 typedef struct dlist { 134 ino_t trunc_bits; /* truncation pattern for a specific map */ 135 dev_t dev; /* the new device id we use */ 136 struct dlist *fow; 137 } DLIST; 138 139 /* 140 * ftree directory access time reset table. When we are done with a 141 * subtree we reset the access and mod time of the directory when the tflag is 142 * set. Not really explicitly specified in the pax spec, but easy and fast to 143 * do (and this may have even been intended in the spec, it is not clear). 144 * table is hashed by inode with chaining. 145 */ 146 147 typedef struct atdir { 148 char *name; /* name of directory to reset */ 149 dev_t dev; /* dev and inode for fast lookup */ 150 ino_t ino; 151 time_t mtime; /* access and mod time to reset to */ 152 time_t atime; 153 struct atdir *fow; 154 } ATDIR; 155 156 /* 157 * created directory time and mode storage entry. After pax is finished during 158 * extraction or copy, we must reset directory access modes and times that 159 * may have been modified after creation (they no longer have the specified 160 * times and/or modes). We must reset time in the reverse order of creation, 161 * because entries are added from the top of the file tree to the bottom. 162 * We MUST reset times from leaf to root (it will not work the other 163 * direction). Entries are recorded into a spool file to make reverse 164 * reading faster. 165 */ 166 167 typedef struct dirdata { 168 int nlen; /* length of the directory name (includes \0) */ 169 off_t npos; /* position in file where this dir name starts */ 170 mode_t mode; /* file mode to restore */ 171 time_t mtime; /* mtime to set */ 172 time_t atime; /* atime to set */ 173 int frc_mode; /* do we force mode settings? */ 174 } DIRDATA; 175