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NetBSD/sbin/restore/restore.c

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/* $NetBSD: restore.c,v 1.22 2021/06/19 13:56:35 christos Exp $ */
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)restore.c 8.3 (Berkeley) 9/13/94";
#else
__RCSID("$NetBSD: restore.c,v 1.22 2021/06/19 13:56:35 christos Exp $");
#endif
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <ufs/ufs/dinode.h>
#include <stdio.h>
#include <string.h>
#include "restore.h"
#include "extern.h"
static char *keyval(int);
/*
* This implements the 't' option.
* List entries on the tape.
*/
long
listfile(const char *name, ino_t ino, int type)
{
long descend = hflag ? GOOD : FAIL;
if (TSTINO(ino, dumpmap) == 0)
return (descend);
vprintf(stdout, "%s", type == LEAF ? "leaf" : "dir ");
fprintf(stdout, "%10ju\t%s\n", (uintmax_t)ino, name);
return (descend);
}
/*
* This implements the 'x' option.
* Request that new entries be extracted.
*/
long
addfile(const char *name, ino_t ino, int type)
{
struct entry *ep;
long descend = hflag ? GOOD : FAIL;
char buf[100];
if (TSTINO(ino, dumpmap) == 0) {
dprintf(stdout, "%s: not on the tape\n", name);
return (descend);
}
if (ino == UFS_WINO && command == 'i' && !vflag)
return (descend);
if (!mflag) {
(void) snprintf(buf, sizeof(buf), "./%ju",
(uintmax_t)ino);
name = buf;
if (type == NODE) {
(void) genliteraldir(name, ino);
return (descend);
}
}
ep = lookupino(ino);
if (ep != NULL) {
if (strcmp(name, myname(ep)) == 0) {
ep->e_flags |= NEW;
return (descend);
}
type |= LINK;
}
ep = addentry(name, ino, type);
if (type == NODE)
newnode(ep);
ep->e_flags |= NEW;
return (descend);
}
/*
* This is used by the 'i' option to undo previous requests made by addfile.
* Delete entries from the request queue.
*/
/* ARGSUSED */
long
deletefile(const char *name, ino_t ino, int type __unused)
{
long descend = hflag ? GOOD : FAIL;
struct entry *ep;
if (TSTINO(ino, dumpmap) == 0)
return (descend);
ep = lookupname(name);
if (ep != NULL) {
ep->e_flags &= ~NEW;
ep->e_flags |= REMOVED;
if (ep->e_type != NODE)
freeentry(ep);
}
return (descend);
}
/*
* The following four routines implement the incremental
* restore algorithm. The first removes old entries, the second
* does renames and calculates the extraction list, the third
* cleans up link names missed by the first two, and the final
* one deletes old directories.
*
* Directories cannot be immediately deleted, as they may have
* other files in them which need to be moved out first. As
* directories to be deleted are found, they are put on the
* following deletion list. After all deletions and renames
* are done, this list is actually deleted.
*/
static struct entry *removelist;
/*
* Remove invalid whiteouts from the old tree.
* Remove unneeded leaves from the old tree.
* Remove directories from the lookup chains.
*/
void
removeoldleaves(void)
{
struct entry *ep, *nextep;
ino_t i, mydirino;
vprintf(stdout, "Mark entries to be removed.\n");
if ((ep = lookupino(UFS_WINO)) != NULL) {
vprintf(stdout, "Delete whiteouts\n");
for ( ; ep != NULL; ep = nextep) {
nextep = ep->e_links;
mydirino = ep->e_parent->e_ino;
/*
* We remove all whiteouts that are in directories
* that have been removed or that have been dumped.
*/
if (TSTINO(mydirino, usedinomap) &&
!TSTINO(mydirino, dumpmap))
continue;
delwhiteout(ep);
freeentry(ep);
}
}
for (i = UFS_ROOTINO + 1; i < maxino; i++) {
ep = lookupino(i);
if (ep == NULL)
continue;
if (TSTINO(i, usedinomap))
continue;
for ( ; ep != NULL; ep = ep->e_links) {
dprintf(stdout, "%s: REMOVE\n", myname(ep));
if (ep->e_type == LEAF) {
removeleaf(ep);
freeentry(ep);
} else {
mktempname(ep);
deleteino(ep->e_ino);
ep->e_next = removelist;
removelist = ep;
}
}
}
}
/*
* For each directory entry on the incremental tape, determine which
* category it falls into as follows:
* KEEP - entries that are to be left alone.
* NEW - new entries to be added.
* EXTRACT - files that must be updated with new contents.
* LINK - new links to be added.
* Renames are done at the same time.
*/
long
nodeupdates(const char *name, ino_t ino, int type)
{
struct entry *ep, *np, *ip;
long descend = GOOD;
int lookuptype = 0;
int key = 0;
/* key values */
# define ONTAPE 0x1 /* inode is on the tape */
# define INOFND 0x2 /* inode already exists */
# define NAMEFND 0x4 /* name already exists */
# define MODECHG 0x8 /* mode of inode changed */
/*
* This routine is called once for each element in the
* directory hierarchy, with a full path name.
* The "type" value is incorrectly specified as LEAF for
* directories that are not on the dump tape.
*
* Check to see if the file is on the tape.
*/
if (TSTINO(ino, dumpmap))
key |= ONTAPE;
/*
* Check to see if the name exists, and if the name is a link.
*/
np = lookupname(name);
if (np != NULL) {
key |= NAMEFND;
ip = lookupino(np->e_ino);
if (ip == NULL)
panic("corrupted symbol table\n");
if (ip != np)
lookuptype = LINK;
}
/*
* Check to see if the inode exists, and if one of its links
* corresponds to the name (if one was found).
*/
ip = lookupino(ino);
if (ip != NULL) {
key |= INOFND;
for (ep = ip->e_links; ep != NULL; ep = ep->e_links) {
if (ep == np) {
ip = ep;
break;
}
}
}
/*
* If both a name and an inode are found, but they do not
* correspond to the same file, then both the inode that has
* been found and the inode corresponding to the name that
* has been found need to be renamed. The current pathname
* is the new name for the inode that has been found. Since
* all files to be deleted have already been removed, the
* named file is either a now unneeded link, or it must live
* under a new name in this dump level. If it is a link, it
* can be removed. If it is not a link, it is given a
* temporary name in anticipation that it will be renamed
* when it is later found by inode number.
*/
if (((key & (INOFND|NAMEFND)) == (INOFND|NAMEFND)) && ip != np) {
if (lookuptype == LINK) {
removeleaf(np);
freeentry(np);
} else {
dprintf(stdout, "name/inode conflict, mktempname %s\n",
myname(np));
mktempname(np);
}
np = NULL;
key &= ~NAMEFND;
}
if ((key & ONTAPE) &&
(((key & INOFND) && ip->e_type != type) ||
((key & NAMEFND) && np->e_type != type)))
key |= MODECHG;
/*
* Decide on the disposition of the file based on its flags.
* Note that we have already handled the case in which
* a name and inode are found that correspond to different files.
* Thus if both NAMEFND and INOFND are set then ip == np.
*/
switch (key) {
/*
* A previously existing file has been found.
* Mark it as KEEP so that other links to the inode can be
* detected, and so that it will not be reclaimed by the search
* for unreferenced names.
*/
case INOFND|NAMEFND:
ip->e_flags |= KEEP;
dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
flagvalues(ip));
break;
/*
* A file on the tape has a name which is the same as a name
* corresponding to a different file in the previous dump.
* Since all files to be deleted have already been removed,
* this file is either a now unneeded link, or it must live
* under a new name in this dump level. If it is a link, it
* can simply be removed. If it is not a link, it is given a
* temporary name in anticipation that it will be renamed
* when it is later found by inode number (see INOFND case
* below). The entry is then treated as a new file.
*/
case ONTAPE|NAMEFND:
case ONTAPE|NAMEFND|MODECHG:
if (lookuptype == LINK) {
removeleaf(np);
freeentry(np);
} else {
mktempname(np);
}
/* FALLTHROUGH */
/*
* A previously non-existent file.
* Add it to the file system, and request its extraction.
* If it is a directory, create it immediately.
* (Since the name is unused there can be no conflict)
*/
case ONTAPE:
ep = addentry(name, ino, type);
if (type == NODE)
newnode(ep);
ep->e_flags |= NEW|KEEP;
dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
flagvalues(ep));
break;
/*
* A file with the same inode number, but a different
* name has been found. If the other name has not already
* been found (indicated by the KEEP flag, see above) then
* this must be a new name for the file, and it is renamed.
* If the other name has been found then this must be a
* link to the file. Hard links to directories are not
* permitted, and are either deleted or converted to
* symbolic links. Finally, if the file is on the tape,
* a request is made to extract it.
*/
case ONTAPE|INOFND:
if (type == LEAF && (ip->e_flags & KEEP) == 0)
ip->e_flags |= EXTRACT;
/* FALLTHROUGH */
case INOFND:
if ((ip->e_flags & KEEP) == 0) {
renameit(myname(ip), name);
moveentry(ip, name);
ip->e_flags |= KEEP;
dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
flagvalues(ip));
break;
}
if (ip->e_type == NODE) {
descend = FAIL;
fprintf(stderr,
"deleted hard link %s to directory %s\n",
name, myname(ip));
break;
}
ep = addentry(name, ino, type|LINK);
ep->e_flags |= NEW;
dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
flagvalues(ep));
break;
/*
* A previously known file which is to be updated. If it is a link,
* then all names referring to the previous file must be removed
* so that the subset of them that remain can be recreated.
*/
case ONTAPE|INOFND|NAMEFND:
if (lookuptype == LINK) {
removeleaf(np);
freeentry(np);
ep = addentry(name, ino, type|LINK);
if (type == NODE)
newnode(ep);
ep->e_flags |= NEW|KEEP;
dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
flagvalues(ep));
break;
}
if (type == LEAF && lookuptype != LINK)
np->e_flags |= EXTRACT;
np->e_flags |= KEEP;
dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
flagvalues(np));
break;
/*
* An inode is being reused in a completely different way.
* Normally an extract can simply do an "unlink" followed
* by a "creat". Here we must do effectively the same
* thing. The complications arise because we cannot really
* delete a directory since it may still contain files
* that we need to rename, so we delete it from the symbol
* table, and put it on the list to be deleted eventually.
* Conversely if a directory is to be created, it must be
* done immediately, rather than waiting until the
* extraction phase.
*/
case ONTAPE|INOFND|MODECHG:
case ONTAPE|INOFND|NAMEFND|MODECHG:
if (ip->e_flags & KEEP) {
badentry(ip, "cannot KEEP and change modes");
break;
}
if (ip->e_type == LEAF) {
/* changing from leaf to node */
for ( ; ip != NULL; ip = ip->e_links) {
if (ip->e_type != LEAF)
badentry(ip,
"NODE and LEAF links to same inode");
removeleaf(ip);
freeentry(ip);
}
ip = addentry(name, ino, type);
newnode(ip);
} else {
/* changing from node to leaf */
if ((ip->e_flags & TMPNAME) == 0)
mktempname(ip);
deleteino(ip->e_ino);
ip->e_next = removelist;
removelist = ip;
ip = addentry(name, ino, type);
}
ip->e_flags |= NEW|KEEP;
dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
flagvalues(ip));
break;
/*
* A hard link to a diirectory that has been removed.
* Ignore it.
*/
case NAMEFND:
dprintf(stdout, "[%s] %s: Extraneous name\n", keyval(key),
name);
descend = FAIL;
break;
/*
* If we find a directory entry for a file that is not on
* the tape, then we must have found a file that was created
* while the dump was in progress. Since we have no contents
* for it, we discard the name knowing that it will be on the
* next incremental tape.
*/
case 0:
fprintf(stderr, "%s: (inode %ju) not found on tape\n",
name, (uintmax_t)ino);
break;
/*
* If any of these arise, something is grievously wrong with
* the current state of the symbol table.
*/
case INOFND|NAMEFND|MODECHG:
case NAMEFND|MODECHG:
case INOFND|MODECHG:
fprintf(stderr, "[%s] %s: inconsistent state\n", keyval(key),
name);
break;
/*
* These states "cannot" arise for any state of the symbol table.
*/
case ONTAPE|MODECHG:
case MODECHG:
default:
panic("[%s] %s: impossible state\n", keyval(key), name);
break;
}
return (descend);
}
/*
* Calculate the active flags in a key.
*/
static char *
keyval(int key)
{
static char keybuf[32];
(void) strcpy(keybuf, "|NIL");
keybuf[0] = '\0';
if (key & ONTAPE)
(void) strcat(keybuf, "|ONTAPE");
if (key & INOFND)
(void) strcat(keybuf, "|INOFND");
if (key & NAMEFND)
(void) strcat(keybuf, "|NAMEFND");
if (key & MODECHG)
(void) strcat(keybuf, "|MODECHG");
return (&keybuf[1]);
}
/*
* Find unreferenced link names.
*/
void
findunreflinks(void)
{
struct entry *ep, *np;
ino_t i;
vprintf(stdout, "Find unreferenced names.\n");
for (i = UFS_ROOTINO; i < maxino; i++) {
ep = lookupino(i);
if (ep == NULL || ep->e_type == LEAF || TSTINO(i, dumpmap) == 0)
continue;
for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
if (np->e_flags == 0) {
dprintf(stdout,
"%s: remove unreferenced name\n",
myname(np));
removeleaf(np);
freeentry(np);
}
}
}
/*
* Any leaves remaining in removed directories is unreferenced.
*/
for (ep = removelist; ep != NULL; ep = ep->e_next) {
for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
if (np->e_type == LEAF) {
if (np->e_flags != 0)
badentry(np, "unreferenced with flags");
dprintf(stdout,
"%s: remove unreferenced name\n",
myname(np));
removeleaf(np);
freeentry(np);
}
}
}
}
/*
* Remove old nodes (directories).
* Note that this routine runs in O(N*D) where:
* N is the number of directory entries to be removed.
* D is the maximum depth of the tree.
* If N == D this can be quite slow. If the list were
* topologically sorted, the deletion could be done in
* time O(N).
*/
void
removeoldnodes(void)
{
struct entry *ep, **prev;
long change;
vprintf(stdout, "Remove old nodes (directories).\n");
do {
change = 0;
prev = &removelist;
for (ep = removelist; ep != NULL; ep = *prev) {
if (ep->e_entries != NULL) {
prev = &ep->e_next;
continue;
}
*prev = ep->e_next;
removenode(ep);
freeentry(ep);
change++;
}
} while (change);
for (ep = removelist; ep != NULL; ep = ep->e_next)
badentry(ep, "cannot remove, non-empty");
}
/*
* This is the routine used to extract files for the 'r' command.
* Extract new leaves.
*/
void
createleaves(const char *symtabfile)
{
struct entry *ep;
ino_t first;
long curvol;
if (command == 'R') {
vprintf(stdout, "Continue extraction of new leaves\n");
} else {
vprintf(stdout, "Extract new leaves.\n");
dumpsymtable(symtabfile, volno);
}
first = lowerbnd(UFS_ROOTINO);
curvol = volno;
while (curfile.ino < maxino) {
first = lowerbnd(first);
/*
* If the next available file is not the one which we
* expect then we have missed one or more files. Since
* we do not request files that were not on the tape,
* the lost files must have been due to a tape read error,
* or a file that was removed while the dump was in progress.
*/
while (first < curfile.ino) {
ep = lookupino(first);
if (ep == NULL)
panic("%ju: bad first\n",
(uintmax_t)first);
fprintf(stderr, "%s: not found on tape\n", myname(ep));
ep->e_flags &= ~(NEW|EXTRACT);
first = lowerbnd(first);
}
/*
* If we find files on the tape that have no corresponding
* directory entries, then we must have found a file that
* was created while the dump was in progress. Since we have
* no name for it, we discard it knowing that it will be
* on the next incremental tape.
*/
if (first != curfile.ino) {
fprintf(stderr, "expected next file %ju, got %ju\n",
(uintmax_t)first,
(uintmax_t)curfile.ino);
skipfile();
goto next;
}
ep = lookupino(curfile.ino);
if (ep == NULL)
panic("unknown file on tape\n");
if ((ep->e_flags & (NEW|EXTRACT)) == 0)
badentry(ep, "unexpected file on tape");
/*
* If the file is to be extracted, then the old file must
* be removed since its type may change from one leaf type
* to another (eg "file" to "character special").
*/
if ((ep->e_flags & EXTRACT) != 0) {
removeleaf(ep);
ep->e_flags &= ~REMOVED;
}
(void) extractfile(myname(ep));
ep->e_flags &= ~(NEW|EXTRACT);
/*
* We checkpoint the restore after every tape reel, so
* as to simplify the amount of work re quired by the
* 'R' command.
*/
next:
if (curvol != volno) {
dumpsymtable(symtabfile, volno);
skipmaps();
curvol = volno;
}
}
}
/*
* This is the routine used to extract files for the 'x' and 'i' commands.
* Efficiently extract a subset of the files on a tape.
*/
void
createfiles(void)
{
ino_t first, next, last;
struct entry *ep;
long curvol;
vprintf(stdout, "Extract requested files\n");
curfile.action = SKIP;
getvol((long)1);
skipmaps();
skipdirs();
first = lowerbnd(UFS_ROOTINO);
last = upperbnd(maxino - 1);
new_volume:
/*
* Decide on the next inode needed in this volume.
*/
next = lowerbnd(curfile.ino);
for (;;) {
first = lowerbnd(first);
last = upperbnd(last);
/*
* Check to see if any files remain to be extracted
*/
if (first > last)
return;
/*
* Reject any volumes with inodes greater
* than the last one needed
*/
if (curfile.ino > last) {
do {
curfile.action = SKIP;
getvol((long)0);
skipmaps();
skipdirs();
} while (curfile.ino > last);
goto new_volume;
}
/*
* Skip across the inodes until the next inode is found
* or an out of order volume change is encountered
*/
do {
curvol = volno;
while (next > curfile.ino && volno == curvol)
skipfile();
skipmaps();
skipdirs();
} while (volno == curvol + 1);
/*
* If volume change out of order occurred the
* current state must be recalculated
*/
if (volno != curvol)
goto new_volume;
/*
* If the current inode is greater than the one we were
* looking for then we missed the one we were looking for.
* Since we only attempt to extract files listed in the
* dump map, the lost files must have been due to a tape
* read error, or a file that was removed while the dump
* was in progress. Thus we report all requested files
* between the one we were looking for, and the one we
* found as missing, and delete their request flags.
*/
while (next < curfile.ino) {
ep = lookupino(next);
if (ep == NULL)
panic("corrupted symbol table\n");
fprintf(stderr, "%s: not found on tape\n", myname(ep));
ep->e_flags &= ~NEW;
next = lowerbnd(next);
}
/*
* The current inode is the one that we are looking for,
* so extract it per its requested name.
*/
if (next == curfile.ino && next <= last) {
ep = lookupino(next);
if (ep == NULL)
panic("corrupted symbol table\n");
(void) extractfile(myname(ep));
ep->e_flags &= ~NEW;
if (volno != curvol) {
skipmaps();
goto new_volume;
}
/*
* Decide the next inode. Note that curfile.ino
* already updated to the next file on the tape,
* and we can't used it since it may be greater
* than `next'.
*/
next = lowerbnd(next);
}
}
}
/*
* Add links.
*/
void
createlinks(void)
{
struct entry *np, *ep;
ino_t i;
char name[BUFSIZ];
if ((ep = lookupino(UFS_WINO)) != NULL) {
vprintf(stdout, "Add whiteouts\n");
for ( ; ep != NULL; ep = ep->e_links) {
if ((ep->e_flags & NEW) == 0)
continue;
(void) addwhiteout(myname(ep));
ep->e_flags &= ~NEW;
}
}
vprintf(stdout, "Add links\n");
for (i = UFS_ROOTINO; i < maxino; i++) {
ep = lookupino(i);
if (ep == NULL)
continue;
for (np = ep->e_links; np != NULL; np = np->e_links) {
if ((np->e_flags & NEW) == 0)
continue;
(void) strcpy(name, myname(ep));
if (ep->e_type == NODE) {
(void) linkit(name, myname(np), SYMLINK);
} else {
(void) linkit(name, myname(np), HARDLINK);
}
np->e_flags &= ~NEW;
}
}
}
/*
* Check the symbol table.
* We do this to insure that all the requested work was done, and
* that no temporary names remain.
*/
void
checkrestore(void)
{
struct entry *ep;
ino_t i;
vprintf(stdout, "Check the symbol table.\n");
for (i = UFS_WINO; i < maxino; i++) {
for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
ep->e_flags &= ~KEEP;
if (ep->e_type == NODE)
ep->e_flags &= ~(NEW|EXISTED);
if (ep->e_flags != 0)
badentry(ep, "incomplete operations");
}
}
}
/*
* Compare with the directory structure on the tape
* A paranoid check that things are as they should be.
*/
long
verifyfile(const char *name, ino_t ino, int type)
{
struct entry *np, *ep;
long descend = GOOD;
ep = lookupname(name);
if (ep == NULL) {
fprintf(stderr, "Warning: missing name %s\n", name);
return (FAIL);
}
np = lookupino(ino);
if (np != ep)
descend = FAIL;
for ( ; np != NULL; np = np->e_links)
if (np == ep)
break;
if (np == NULL)
panic("missing inumber %ju\n", (uintmax_t)ino);
if (ep->e_type == LEAF && type != LEAF)
badentry(ep, "type should be LEAF");
return (descend);
}
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