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Diffstat (limited to 'bin/pax/tables.h')
| -rw-r--r-- | bin/pax/tables.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/bin/pax/tables.h b/bin/pax/tables.h new file mode 100644 index 000000000000..fb5bc437b0a0 --- /dev/null +++ b/bin/pax/tables.h @@ -0,0 +1,171 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1992 Keith Muller. + * Copyright (c) 1992, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Keith Muller of the University of California, San Diego. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)tables.h 8.1 (Berkeley) 5/31/93 + * $FreeBSD$ + */ + +/* + * data structures and constants used by the different databases kept by pax + */ + +/* + * Hash Table Sizes MUST BE PRIME, if set too small performance suffers. + * Probably safe to expect 500000 inodes per tape. Assuming good key + * distribution (inodes) chains of under 50 long (worse case) is ok. + */ +#define L_TAB_SZ 2503 /* hard link hash table size */ +#define F_TAB_SZ 50503 /* file time hash table size */ +#define N_TAB_SZ 541 /* interactive rename hash table */ +#define D_TAB_SZ 317 /* unique device mapping table */ +#define A_TAB_SZ 317 /* ftree dir access time reset table */ +#define MAXKEYLEN 64 /* max number of chars for hash */ + +/* + * file hard link structure (hashed by dev/ino and chained) used to find the + * hard links in a file system or with some archive formats (cpio) + */ +typedef struct hrdlnk { + char *name; /* name of first file seen with this ino/dev */ + dev_t dev; /* files device number */ + ino_t ino; /* files inode number */ + u_long nlink; /* expected link count */ + struct hrdlnk *fow; +} HRDLNK; + +/* + * Archive write update file time table (the -u, -C flag), hashed by filename. + * Filenames are stored in a scratch file at seek offset into the file. The + * file time (mod time) and the file name length (for a quick check) are + * stored in a hash table node. We were forced to use a scratch file because + * with -u, the mtime for every node in the archive must always be available + * to compare against (and this data can get REALLY large with big archives). + * By being careful to read only when we have a good chance of a match, the + * performance loss is not measurable (and the size of the archive we can + * handle is greatly increased). + */ +typedef struct ftm { + int namelen; /* file name length */ + time_t mtime; /* files last modification time */ + off_t seek; /* location in scratch file */ + struct ftm *fow; +} FTM; + +/* + * Interactive rename table (-i flag), hashed by orig filename. + * We assume this will not be a large table as this mapping data can only be + * obtained through interactive input by the user. Nobody is going to type in + * changes for 500000 files? We use chaining to resolve collisions. + */ + +typedef struct namt { + char *oname; /* old name */ + char *nname; /* new name typed in by the user */ + struct namt *fow; +} NAMT; + +/* + * Unique device mapping tables. Some protocols (e.g. cpio) require that the + * <c_dev,c_ino> pair will uniquely identify a file in an archive unless they + * are links to the same file. Appending to archives can break this. For those + * protocols that have this requirement we map c_dev to a unique value not seen + * in the archive when we append. We also try to handle inode truncation with + * this table. (When the inode field in the archive header are too small, we + * remap the dev on writes to remove accidental collisions). + * + * The list is hashed by device number using chain collision resolution. Off of + * each DEVT are linked the various remaps for this device based on those bits + * in the inode which were truncated. For example if we are just remapping to + * avoid a device number during an update append, off the DEVT we would have + * only a single DLIST that has a truncation id of 0 (no inode bits were + * stripped for this device so far). When we spot inode truncation we create + * a new mapping based on the set of bits in the inode which were stripped off. + * so if the top four bits of the inode are stripped and they have a pattern of + * 0110...... (where . are those bits not truncated) we would have a mapping + * assigned for all inodes that has the same 0110.... pattern (with this dev + * number of course). This keeps the mapping sparse and should be able to store + * close to the limit of files which can be represented by the optimal + * combination of dev and inode bits, and without creating a fouled up archive. + * Note we also remap truncated devs in the same way (an exercise for the + * dedicated reader; always wanted to say that...:) + */ + +typedef struct devt { + dev_t dev; /* the orig device number we now have to map */ + struct devt *fow; /* new device map list */ + struct dlist *list; /* map list based on inode truncation bits */ +} DEVT; + +typedef struct dlist { + ino_t trunc_bits; /* truncation pattern for a specific map */ + dev_t dev; /* the new device id we use */ + struct dlist *fow; +} DLIST; + +/* + * ftree directory access time reset table. When we are done with with a + * subtree we reset the access and mod time of the directory when the tflag is + * set. Not really explicitly specified in the pax spec, but easy and fast to + * do (and this may have even been intended in the spec, it is not clear). + * table is hashed by inode with chaining. + */ + +typedef struct atdir { + char *name; /* name of directory to reset */ + dev_t dev; /* dev and inode for fast lookup */ + ino_t ino; + time_t mtime; /* access and mod time to reset to */ + time_t atime; + struct atdir *fow; +} ATDIR; + +/* + * created directory time and mode storage entry. After pax is finished during + * extraction or copy, we must reset directory access modes and times that + * may have been modified after creation (they no longer have the specified + * times and/or modes). We must reset time in the reverse order of creation, + * because entries are added from the top of the file tree to the bottom. + * We MUST reset times from leaf to root (it will not work the other + * direction). Entries are recorded into a spool file to make reverse + * reading faster. + */ + +typedef struct dirdata { + int nlen; /* length of the directory name (includes \0) */ + off_t npos; /* position in file where this dir name starts */ + mode_t mode; /* file mode to restore */ + time_t mtime; /* mtime to set */ + time_t atime; /* atime to set */ + int frc_mode; /* do we force mode settings? */ +} DIRDATA; |