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mirror of https://git.FreeBSD.org/src.git synced 2024-12-20 11:11:24 +00:00
freebsd/sbin/restore/restore.c
David Malone cbc8bb98ef Add a "-D" flag to restore which puts it into "degraded" mode. This
makes restore less efficient, but it makes a bigger effore to read
corrupted dumps. Specifiacally, when in degreded mode:

	1) Restore shifts the input by 1 byte if it sees a problem,
	rather than one tape block.
	2) It doesn't assume the inodes are stored in ascending order.
	3) It turns some panics into warning printfs.

We also verify some fields more carefully than before.

There's probably more a degreded mode could do, but this seems to
help a lot.

Approved by:	imp, iedowse, mckusick
MFC after:	3 weeks
2006-12-05 11:18:51 +00:00

860 lines
22 KiB
C

/*
* 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.
* 4. 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)restore.c 8.3 (Berkeley) 9/13/94";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <ufs/ufs/dinode.h>
#include "restore.h"
#include "extern.h"
static char *keyval(int);
/*
* This implements the 't' option.
* List entries on the tape.
*/
long
listfile(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, "%10d\t%s\n", ino, name);
return (descend);
}
/*
* This implements the 'x' option.
* Request that new entries be extracted.
*/
long
addfile(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 == WINO && command == 'i' && !vflag)
return (descend);
if (!mflag) {
(void) sprintf(buf, "./%u", 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(char *name, ino_t ino, int type)
{
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(WINO))) {
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 = 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(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 = lookupino(ino); 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 directory 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 %d) not found on tape\n",
name, 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 = 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(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(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("%d: bad first\n", 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 %d, got %d\n",
first, 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 (e.g. "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 required 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(ROOTINO);
last = upperbnd(maxino - 1);
for (;;) {
curvol = volno;
first = lowerbnd(first);
last = upperbnd(last);
/*
* Check to see if any files remain to be extracted
*/
if (first > last)
return;
if (Dflag) {
if (curfile.ino == maxino)
return;
if((ep = lookupino(curfile.ino)) != NULL &&
(ep->e_flags & (NEW|EXTRACT))) {
goto justgetit;
} else {
skipfile();
continue;
}
}
/*
* Reject any volumes with inodes greater than the last
* one needed, so that we can quickly skip backwards to
* a volume containing useful inodes. We can't do this
* if there are no further volumes available (curfile.ino
* >= maxino) or if we are already at the first tape.
*/
if (curfile.ino > last && curfile.ino < maxino && volno > 1) {
curfile.action = SKIP;
getvol((long)0);
skipmaps();
skipdirs();
continue;
}
/*
* Decide on the next inode needed.
* Skip across the inodes until it is found
* or a volume change is encountered
*/
if (curfile.ino < maxino) {
next = lowerbnd(curfile.ino);
while (next > curfile.ino && volno == curvol)
skipfile();
if (volno != curvol) {
skipmaps();
skipdirs();
continue;
}
} else {
/*
* No further volumes or inodes available. Set
* `next' to the first inode, so that a warning
* is emitted below for each missing file.
*/
next = first;
}
/*
* 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");
justgetit:
(void) extractfile(myname(ep));
ep->e_flags &= ~NEW;
if (volno != curvol)
skipmaps();
}
}
}
/*
* Add links.
*/
void
createlinks(void)
{
struct entry *np, *ep;
ino_t i;
char name[BUFSIZ];
if ((ep = lookupino(WINO))) {
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 = 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 = 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(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 %d\n", ino);
if (ep->e_type == LEAF && type != LEAF)
badentry(ep, "type should be LEAF");
return (descend);
}