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0061238fb0
freebsd-dev/sbin/fsck_ffs/dir.c
Kirk McKusick 0061238fb0 This update eliminates a kernel stack disclosure bug in UFS/FFS 
directory entries that is caused by uninitialized directory entry
padding written to the disk. It can be viewed by any user with read
access to that directory. Up to 3 bytes of kernel stack are disclosed
per file entry, depending on the the amount of padding the kernel
needs to pad out the entry to a 32 bit boundry. The offset in the
kernel stack that is disclosed is a function of the filename size.
Furthermore, if the user can create files in a directory, this 3
byte window can be expanded 3 bytes at a time to a 254 byte window
with 75% of the data in that window exposed. The additional exposure
is done by removing the entry, creating a new entry with a 4-byte
longer name, extracting 3 more bytes by reading the directory, and
repeating until a 252 byte name is created.

This exploit works in part because the area of the kernel stack
that is being disclosed is in an area that typically doesn't change
that often (perhaps a few times a second on a lightly loaded system),
and these file creates and unlinks themselves don't overwrite the
area of kernel stack being disclosed.

It appears that this bug originated with the creation of the Fast
File System in 4.1b-BSD (Circa 1982, more than 36 years ago!), and
is likely present in every Unix or Unix-like system that uses
UFS/FFS. Amazingly, nobody noticed until now.

This update also adds the -z flag to fsck_ffs to have it scrub
the leaked information in the name padding of existing directories.
It only needs to be run once on each UFS/FFS filesystem after a
patched kernel is installed and running.

Submitted by: David G. Lawrence <dg@dglawrence.com>
Reviewed by:  kib
MFC after:    1 week
2019-05-03 21:54:14 +00:00

789 lines
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1980, 1986, 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.
*/
#if 0
#ifndef lint
static const char sccsid[] = "@(#)dir.c 8.8 (Berkeley) 4/28/95";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ffs/fs.h>
#include <err.h>
#include <string.h>
#include "fsck.h"
static struct dirtemplate emptydir = {
0, DIRBLKSIZ, DT_UNKNOWN, 0, "",
0, 0, DT_UNKNOWN, 0, ""
};
static struct dirtemplate dirhead = {
0, 12, DT_DIR, 1, ".",
0, DIRBLKSIZ - 12, DT_DIR, 2, ".."
};
static int chgino(struct inodesc *);
static int dircheck(struct inodesc *, struct direct *);
static int expanddir(union dinode *dp, char *name);
static void freedir(ino_t ino, ino_t parent);
static struct direct *fsck_readdir(struct inodesc *);
static struct bufarea *getdirblk(ufs2_daddr_t blkno, long size);
static int lftempname(char *bufp, ino_t ino);
static int mkentry(struct inodesc *);
/*
* Propagate connected state through the tree.
*/
void
propagate(void)
{
struct inoinfo **inpp, *inp;
struct inoinfo **inpend;
long change;
inpend = &inpsort[inplast];
do {
change = 0;
for (inpp = inpsort; inpp < inpend; inpp++) {
inp = *inpp;
if (inp->i_parent == 0)
continue;
if (inoinfo(inp->i_parent)->ino_state == DFOUND &&
INO_IS_DUNFOUND(inp->i_number)) {
inoinfo(inp->i_number)->ino_state = DFOUND;
change++;
}
}
} while (change > 0);
}
/*
* Scan each entry in a directory block.
*/
int
dirscan(struct inodesc *idesc)
{
struct direct *dp;
struct bufarea *bp;
u_int dsize, n;
long blksiz;
char dbuf[DIRBLKSIZ];
if (idesc->id_type != DATA)
errx(EEXIT, "wrong type to dirscan %d", idesc->id_type);
if (idesc->id_entryno == 0 &&
(idesc->id_filesize & (DIRBLKSIZ - 1)) != 0)
idesc->id_filesize = roundup(idesc->id_filesize, DIRBLKSIZ);
blksiz = idesc->id_numfrags * sblock.fs_fsize;
if (chkrange(idesc->id_blkno, idesc->id_numfrags)) {
idesc->id_filesize -= blksiz;
return (SKIP);
}
idesc->id_loc = 0;
for (dp = fsck_readdir(idesc); dp != NULL; dp = fsck_readdir(idesc)) {
dsize = dp->d_reclen;
if (dsize > sizeof(dbuf))
dsize = sizeof(dbuf);
memmove(dbuf, dp, (size_t)dsize);
idesc->id_dirp = (struct direct *)dbuf;
if ((n = (*idesc->id_func)(idesc)) & ALTERED) {
bp = getdirblk(idesc->id_blkno, blksiz);
memmove(bp->b_un.b_buf + idesc->id_loc - dsize, dbuf,
(size_t)dsize);
dirty(bp);
sbdirty();
rerun = 1;
}
if (n & STOP)
return (n);
}
return (idesc->id_filesize > 0 ? KEEPON : STOP);
}
/*
* get next entry in a directory.
*/
static struct direct *
fsck_readdir(struct inodesc *idesc)
{
struct direct *dp, *ndp;
struct bufarea *bp;
long size, blksiz, fix, dploc;
int dc;
blksiz = idesc->id_numfrags * sblock.fs_fsize;
bp = getdirblk(idesc->id_blkno, blksiz);
if (idesc->id_loc % DIRBLKSIZ == 0 && idesc->id_filesize > 0 &&
idesc->id_loc < blksiz) {
dp = (struct direct *)(bp->b_un.b_buf + idesc->id_loc);
if ((dc = dircheck(idesc, dp)) > 0) {
if (dc == 2) {
/*
* dircheck() cleared unused directory space.
* Mark the buffer as dirty to write it out.
*/
dirty(bp);
}
goto dpok;
}
if (idesc->id_fix == IGNORE)
return (0);
fix = dofix(idesc, "DIRECTORY CORRUPTED");
bp = getdirblk(idesc->id_blkno, blksiz);
dp = (struct direct *)(bp->b_un.b_buf + idesc->id_loc);
dp->d_reclen = DIRBLKSIZ;
dp->d_ino = 0;
dp->d_type = 0;
dp->d_namlen = 0;
dp->d_name[0] = '\0';
if (fix)
dirty(bp);
idesc->id_loc += DIRBLKSIZ;
idesc->id_filesize -= DIRBLKSIZ;
return (dp);
}
dpok:
if (idesc->id_filesize <= 0 || idesc->id_loc >= blksiz)
return NULL;
dploc = idesc->id_loc;
dp = (struct direct *)(bp->b_un.b_buf + dploc);
idesc->id_loc += dp->d_reclen;
idesc->id_filesize -= dp->d_reclen;
if ((idesc->id_loc % DIRBLKSIZ) == 0)
return (dp);
ndp = (struct direct *)(bp->b_un.b_buf + idesc->id_loc);
if (idesc->id_loc < blksiz && idesc->id_filesize > 0) {
if ((dc = dircheck(idesc, ndp)) == 0) {
size = DIRBLKSIZ - (idesc->id_loc % DIRBLKSIZ);
idesc->id_loc += size;
idesc->id_filesize -= size;
if (idesc->id_fix == IGNORE)
return (0);
fix = dofix(idesc, "DIRECTORY CORRUPTED");
bp = getdirblk(idesc->id_blkno, blksiz);
dp = (struct direct *)(bp->b_un.b_buf + dploc);
dp->d_reclen += size;
if (fix)
dirty(bp);
} else if (dc == 2) {
/*
* dircheck() cleared unused directory space.
* Mark the buffer as dirty to write it out.
*/
dirty(bp);
}
}
return (dp);
}
/*
* Verify that a directory entry is valid.
* This is a superset of the checks made in the kernel.
* Also optionally clears padding and unused directory space.
*
* Returns 0 if the entry is bad, 1 if the entry is good and no changes
* were made, and 2 if the entry is good but modified to clear out padding
* and unused space and needs to be written back to disk.
*/
static int
dircheck(struct inodesc *idesc, struct direct *dp)
{
size_t size;
char *cp;
u_char type;
u_int8_t namlen;
int spaceleft, modified, unused;
modified = 0;
spaceleft = DIRBLKSIZ - (idesc->id_loc % DIRBLKSIZ);
if (dp->d_reclen == 0 ||
dp->d_reclen > spaceleft ||
(dp->d_reclen & (DIR_ROUNDUP - 1)) != 0)
goto bad;
if (dp->d_ino == 0) {
/*
* Special case of an unused directory entry. Normally
* the kernel would coalesce unused space with the previous
* entry by extending its d_reclen, but there are situations
* (e.g. fsck) where that doesn't occur.
* If we're clearing out directory cruft (-z flag), then make
* sure this entry gets fully cleared as well.
*/
if (zflag && fswritefd >= 0) {
if (dp->d_type != 0) {
dp->d_type = 0;
modified = 1;
}
if (dp->d_namlen != 0) {
dp->d_namlen = 0;
modified = 1;
}
if (dp->d_name[0] != '\0') {
dp->d_name[0] = '\0';
modified = 1;
}
}
goto good;
}
size = DIRSIZ(0, dp);
namlen = dp->d_namlen;
type = dp->d_type;
if (dp->d_reclen < size ||
idesc->id_filesize < size ||
namlen == 0 ||
type > 15)
goto bad;
for (cp = dp->d_name, size = 0; size < namlen; size++)
if (*cp == '\0' || (*cp++ == '/'))
goto bad;
if (*cp != '\0')
goto bad;
good:
if (zflag && fswritefd >= 0) {
/*
* Clear unused directory entry space, including the d_name
* padding.
*/
/* First figure the number of pad bytes. */
unused = roundup2(namlen + 1, DIR_ROUNDUP) - (namlen + 1);
/* Add in the free space to the end of the record. */
unused += dp->d_reclen - DIRSIZ(0, dp);
/*
* Now clear out the unused space, keeping track if we actually
* changed anything.
*/
for (cp = &dp->d_name[namlen + 1]; unused > 0; unused--, cp++) {
if (*cp != '\0') {
*cp = '\0';
modified = 1;
}
}
if (modified) {
return 2;
}
}
return (1);
bad:
if (debug)
printf("Bad dir: ino %d reclen %d namlen %d type %d name %s\n",
dp->d_ino, dp->d_reclen, dp->d_namlen, dp->d_type,
dp->d_name);
return (0);
}
void
direrror(ino_t ino, const char *errmesg)
{
fileerror(ino, ino, errmesg);
}
void
fileerror(ino_t cwd, ino_t ino, const char *errmesg)
{
union dinode *dp;
char pathbuf[MAXPATHLEN + 1];
pwarn("%s ", errmesg);
if (ino < UFS_ROOTINO || ino > maxino) {
pfatal("out-of-range inode number %ju", (uintmax_t)ino);
return;
}
dp = ginode(ino);
prtinode(ino, dp);
printf("\n");
getpathname(pathbuf, cwd, ino);
if (ftypeok(dp))
pfatal("%s=%s\n",
(DIP(dp, di_mode) & IFMT) == IFDIR ? "DIR" : "FILE",
pathbuf);
else
pfatal("NAME=%s\n", pathbuf);
}
void
adjust(struct inodesc *idesc, int lcnt)
{
union dinode *dp;
int saveresolved;
dp = ginode(idesc->id_number);
if (DIP(dp, di_nlink) == lcnt) {
/*
* If we have not hit any unresolved problems, are running
* in preen mode, and are on a file system using soft updates,
* then just toss any partially allocated files.
*/
if (resolved && (preen || bkgrdflag) && usedsoftdep) {
clri(idesc, "UNREF", 1);
return;
} else {
/*
* The file system can be marked clean even if
* a file is not linked up, but is cleared.
* Hence, resolved should not be cleared when
* linkup is answered no, but clri is answered yes.
*/
saveresolved = resolved;
if (linkup(idesc->id_number, (ino_t)0, NULL) == 0) {
resolved = saveresolved;
clri(idesc, "UNREF", 0);
return;
}
/*
* Account for the new reference created by linkup().
*/
dp = ginode(idesc->id_number);
lcnt--;
}
}
if (lcnt != 0) {
pwarn("LINK COUNT %s", (lfdir == idesc->id_number) ? lfname :
((DIP(dp, di_mode) & IFMT) == IFDIR ? "DIR" : "FILE"));
prtinode(idesc->id_number, dp);
printf(" COUNT %d SHOULD BE %d",
DIP(dp, di_nlink), DIP(dp, di_nlink) - lcnt);
if (preen || usedsoftdep) {
if (lcnt < 0) {
printf("\n");
pfatal("LINK COUNT INCREASING");
}
if (preen)
printf(" (ADJUSTED)\n");
}
if (preen || reply("ADJUST") == 1) {
if (bkgrdflag == 0) {
DIP_SET(dp, di_nlink, DIP(dp, di_nlink) - lcnt);
inodirty(dp);
} else {
cmd.value = idesc->id_number;
cmd.size = -lcnt;
if (debug)
printf("adjrefcnt ino %ld amt %lld\n",
(long)cmd.value,
(long long)cmd.size);
if (sysctl(adjrefcnt, MIBSIZE, 0, 0,
&cmd, sizeof cmd) == -1)
rwerror("ADJUST INODE", cmd.value);
}
}
}
}
static int
mkentry(struct inodesc *idesc)
{
struct direct *dirp = idesc->id_dirp;
struct direct newent;
int newlen, oldlen;
newent.d_namlen = strlen(idesc->id_name);
newlen = DIRSIZ(0, &newent);
if (dirp->d_ino != 0)
oldlen = DIRSIZ(0, dirp);
else
oldlen = 0;
if (dirp->d_reclen - oldlen < newlen)
return (KEEPON);
newent.d_reclen = dirp->d_reclen - oldlen;
dirp->d_reclen = oldlen;
dirp = (struct direct *)(((char *)dirp) + oldlen);
dirp->d_ino = idesc->id_parent; /* ino to be entered is in id_parent */
dirp->d_reclen = newent.d_reclen;
dirp->d_type = inoinfo(idesc->id_parent)->ino_type;
dirp->d_namlen = newent.d_namlen;
memmove(dirp->d_name, idesc->id_name, (size_t)newent.d_namlen + 1);
return (ALTERED|STOP);
}
static int
chgino(struct inodesc *idesc)
{
struct direct *dirp = idesc->id_dirp;
if (memcmp(dirp->d_name, idesc->id_name, (int)dirp->d_namlen + 1))
return (KEEPON);
dirp->d_ino = idesc->id_parent;
dirp->d_type = inoinfo(idesc->id_parent)->ino_type;
return (ALTERED|STOP);
}
int
linkup(ino_t orphan, ino_t parentdir, char *name)
{
union dinode *dp;
int lostdir;
ino_t oldlfdir;
struct inodesc idesc;
char tempname[BUFSIZ];
memset(&idesc, 0, sizeof(struct inodesc));
dp = ginode(orphan);
lostdir = (DIP(dp, di_mode) & IFMT) == IFDIR;
pwarn("UNREF %s ", lostdir ? "DIR" : "FILE");
prtinode(orphan, dp);
printf("\n");
if (preen && DIP(dp, di_size) == 0)
return (0);
if (cursnapshot != 0) {
pfatal("FILE LINKUP IN SNAPSHOT");
return (0);
}
if (preen)
printf(" (RECONNECTED)\n");
else
if (reply("RECONNECT") == 0)
return (0);
if (lfdir == 0) {
dp = ginode(UFS_ROOTINO);
idesc.id_name = strdup(lfname);
idesc.id_type = DATA;
idesc.id_func = findino;
idesc.id_number = UFS_ROOTINO;
if ((ckinode(dp, &idesc) & FOUND) != 0) {
lfdir = idesc.id_parent;
} else {
pwarn("NO lost+found DIRECTORY");
if (preen || reply("CREATE")) {
lfdir = allocdir(UFS_ROOTINO, (ino_t)0, lfmode);
if (lfdir != 0) {
if (makeentry(UFS_ROOTINO, lfdir,
lfname) != 0) {
numdirs++;
if (preen)
printf(" (CREATED)\n");
} else {
freedir(lfdir, UFS_ROOTINO);
lfdir = 0;
if (preen)
printf("\n");
}
}
}
}
if (lfdir == 0) {
pfatal("SORRY. CANNOT CREATE lost+found DIRECTORY");
printf("\n\n");
return (0);
}
}
dp = ginode(lfdir);
if ((DIP(dp, di_mode) & IFMT) != IFDIR) {
pfatal("lost+found IS NOT A DIRECTORY");
if (reply("REALLOCATE") == 0)
return (0);
oldlfdir = lfdir;
if ((lfdir = allocdir(UFS_ROOTINO, (ino_t)0, lfmode)) == 0) {
pfatal("SORRY. CANNOT CREATE lost+found DIRECTORY\n\n");
return (0);
}
if ((changeino(UFS_ROOTINO, lfname, lfdir) & ALTERED) == 0) {
pfatal("SORRY. CANNOT CREATE lost+found DIRECTORY\n\n");
return (0);
}
inodirty(dp);
idesc.id_type = ADDR;
idesc.id_func = pass4check;
idesc.id_number = oldlfdir;
adjust(&idesc, inoinfo(oldlfdir)->ino_linkcnt + 1);
inoinfo(oldlfdir)->ino_linkcnt = 0;
dp = ginode(lfdir);
}
if (inoinfo(lfdir)->ino_state != DFOUND) {
pfatal("SORRY. NO lost+found DIRECTORY\n\n");
return (0);
}
(void)lftempname(tempname, orphan);
if (makeentry(lfdir, orphan, (name ? name : tempname)) == 0) {
pfatal("SORRY. NO SPACE IN lost+found DIRECTORY");
printf("\n\n");
return (0);
}
inoinfo(orphan)->ino_linkcnt--;
if (lostdir) {
if ((changeino(orphan, "..", lfdir) & ALTERED) == 0 &&
parentdir != (ino_t)-1)
(void)makeentry(orphan, lfdir, "..");
dp = ginode(lfdir);
DIP_SET(dp, di_nlink, DIP(dp, di_nlink) + 1);
inodirty(dp);
inoinfo(lfdir)->ino_linkcnt++;
pwarn("DIR I=%lu CONNECTED. ", (u_long)orphan);
if (parentdir != (ino_t)-1) {
printf("PARENT WAS I=%lu\n", (u_long)parentdir);
/*
* The parent directory, because of the ordering
* guarantees, has had the link count incremented
* for the child, but no entry was made. This
* fixes the parent link count so that fsck does
* not need to be rerun.
*/
inoinfo(parentdir)->ino_linkcnt++;
}
if (preen == 0)
printf("\n");
}
return (1);
}
/*
* fix an entry in a directory.
*/
int
changeino(ino_t dir, const char *name, ino_t newnum)
{
struct inodesc idesc;
memset(&idesc, 0, sizeof(struct inodesc));
idesc.id_type = DATA;
idesc.id_func = chgino;
idesc.id_number = dir;
idesc.id_fix = DONTKNOW;
idesc.id_name = strdup(name);
idesc.id_parent = newnum; /* new value for name */
return (ckinode(ginode(dir), &idesc));
}
/*
* make an entry in a directory
*/
int
makeentry(ino_t parent, ino_t ino, const char *name)
{
union dinode *dp;
struct inodesc idesc;
char pathbuf[MAXPATHLEN + 1];
if (parent < UFS_ROOTINO || parent >= maxino ||
ino < UFS_ROOTINO || ino >= maxino)
return (0);
memset(&idesc, 0, sizeof(struct inodesc));
idesc.id_type = DATA;
idesc.id_func = mkentry;
idesc.id_number = parent;
idesc.id_parent = ino; /* this is the inode to enter */
idesc.id_fix = DONTKNOW;
idesc.id_name = strdup(name);
dp = ginode(parent);
if (DIP(dp, di_size) % DIRBLKSIZ) {
DIP_SET(dp, di_size, roundup(DIP(dp, di_size), DIRBLKSIZ));
inodirty(dp);
}
if ((ckinode(dp, &idesc) & ALTERED) != 0)
return (1);
getpathname(pathbuf, parent, parent);
dp = ginode(parent);
if (expanddir(dp, pathbuf) == 0)
return (0);
return (ckinode(dp, &idesc) & ALTERED);
}
/*
* Attempt to expand the size of a directory
*/
static int
expanddir(union dinode *dp, char *name)
{
ufs2_daddr_t lastbn, newblk;
struct bufarea *bp;
char *cp, firstblk[DIRBLKSIZ];
lastbn = lblkno(&sblock, DIP(dp, di_size));
if (lastbn >= UFS_NDADDR - 1 || DIP(dp, di_db[lastbn]) == 0 ||
DIP(dp, di_size) == 0)
return (0);
if ((newblk = allocblk(sblock.fs_frag)) == 0)
return (0);
DIP_SET(dp, di_db[lastbn + 1], DIP(dp, di_db[lastbn]));
DIP_SET(dp, di_db[lastbn], newblk);
DIP_SET(dp, di_size, DIP(dp, di_size) + sblock.fs_bsize);
DIP_SET(dp, di_blocks, DIP(dp, di_blocks) + btodb(sblock.fs_bsize));
bp = getdirblk(DIP(dp, di_db[lastbn + 1]),
sblksize(&sblock, DIP(dp, di_size), lastbn + 1));
if (bp->b_errs)
goto bad;
memmove(firstblk, bp->b_un.b_buf, DIRBLKSIZ);
bp = getdirblk(newblk, sblock.fs_bsize);
if (bp->b_errs)
goto bad;
memmove(bp->b_un.b_buf, firstblk, DIRBLKSIZ);
for (cp = &bp->b_un.b_buf[DIRBLKSIZ];
cp < &bp->b_un.b_buf[sblock.fs_bsize];
cp += DIRBLKSIZ)
memmove(cp, &emptydir, sizeof emptydir);
dirty(bp);
bp = getdirblk(DIP(dp, di_db[lastbn + 1]),
sblksize(&sblock, DIP(dp, di_size), lastbn + 1));
if (bp->b_errs)
goto bad;
memmove(bp->b_un.b_buf, &emptydir, sizeof emptydir);
pwarn("NO SPACE LEFT IN %s", name);
if (preen)
printf(" (EXPANDED)\n");
else if (reply("EXPAND") == 0)
goto bad;
dirty(bp);
inodirty(dp);
return (1);
bad:
DIP_SET(dp, di_db[lastbn], DIP(dp, di_db[lastbn + 1]));
DIP_SET(dp, di_db[lastbn + 1], 0);
DIP_SET(dp, di_size, DIP(dp, di_size) - sblock.fs_bsize);
DIP_SET(dp, di_blocks, DIP(dp, di_blocks) - btodb(sblock.fs_bsize));
freeblk(newblk, sblock.fs_frag);
return (0);
}
/*
* allocate a new directory
*/
ino_t
allocdir(ino_t parent, ino_t request, int mode)
{
ino_t ino;
char *cp;
union dinode *dp;
struct bufarea *bp;
struct inoinfo *inp;
struct dirtemplate *dirp;
ino = allocino(request, IFDIR|mode);
dirp = &dirhead;
dirp->dot_ino = ino;
dirp->dotdot_ino = parent;
dp = ginode(ino);
bp = getdirblk(DIP(dp, di_db[0]), sblock.fs_fsize);
if (bp->b_errs) {
freeino(ino);
return (0);
}
memmove(bp->b_un.b_buf, dirp, sizeof(struct dirtemplate));
for (cp = &bp->b_un.b_buf[DIRBLKSIZ];
cp < &bp->b_un.b_buf[sblock.fs_fsize];
cp += DIRBLKSIZ)
memmove(cp, &emptydir, sizeof emptydir);
dirty(bp);
DIP_SET(dp, di_nlink, 2);
inodirty(dp);
if (ino == UFS_ROOTINO) {
inoinfo(ino)->ino_linkcnt = DIP(dp, di_nlink);
cacheino(dp, ino);
return(ino);
}
if (!INO_IS_DVALID(parent)) {
freeino(ino);
return (0);
}
cacheino(dp, ino);
inp = getinoinfo(ino);
inp->i_parent = parent;
inp->i_dotdot = parent;
inoinfo(ino)->ino_state = inoinfo(parent)->ino_state;
if (inoinfo(ino)->ino_state == DSTATE) {
inoinfo(ino)->ino_linkcnt = DIP(dp, di_nlink);
inoinfo(parent)->ino_linkcnt++;
}
dp = ginode(parent);
DIP_SET(dp, di_nlink, DIP(dp, di_nlink) + 1);
inodirty(dp);
return (ino);
}
/*
* free a directory inode
*/
static void
freedir(ino_t ino, ino_t parent)
{
union dinode *dp;
if (ino != parent) {
dp = ginode(parent);
DIP_SET(dp, di_nlink, DIP(dp, di_nlink) - 1);
inodirty(dp);
}
freeino(ino);
}
/*
* generate a temporary name for the lost+found directory.
*/
static int
lftempname(char *bufp, ino_t ino)
{
ino_t in;
char *cp;
int namlen;
cp = bufp + 2;
for (in = maxino; in > 0; in /= 10)
cp++;
*--cp = 0;
namlen = cp - bufp;
in = ino;
while (cp > bufp) {
*--cp = (in % 10) + '0';
in /= 10;
}
*cp = '#';
return (namlen);
}
/*
* Get a directory block.
* Insure that it is held until another is requested.
*/
static struct bufarea *
getdirblk(ufs2_daddr_t blkno, long size)
{
if (pdirbp != NULL)
pdirbp->b_flags &= ~B_INUSE;
pdirbp = getdatablk(blkno, size, BT_DIRDATA);
return (pdirbp);
}
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