void
update_mtab (const char *dir, struct mntent *instead)
{
mntFILE *mfp, *mftmp;
const char *fnam = MOUNTED;
struct mntentchn mtabhead; /* dummy */
struct mntentchn *mc, *mc0, *absent = NULL;
if (mtab_does_not_exist() || !mtab_is_writable())
return;
lock_mtab();
/* having locked mtab, read it again */
mc0 = mc = &mtabhead;
mc->nxt = mc->prev = NULL;
mfp = nfs_setmntent(fnam, "r");
if (mfp == NULL || mfp->mntent_fp == NULL) {
int errsv = errno;
nfs_error (_("cannot open %s (%s) - mtab not updated"),
fnam, strerror (errsv));
goto leave;
}
read_mntentchn(mfp, fnam, mc);
/* find last occurrence of dir */
for (mc = mc0->prev; mc && mc != mc0; mc = mc->prev)
if (streq(mc->m.mnt_dir, dir))
break;
if (mc && mc != mc0) {
if (instead == NULL) {
/* An umount - remove entry */
if (mc && mc != mc0) {
mc->prev->nxt = mc->nxt;
mc->nxt->prev = mc->prev;
free(mc);
}
} else {
/* A remount */
mc->m.mnt_opts = instead->mnt_opts;
}
} else if (instead) {
/* not found, add a new entry */
absent = xmalloc(sizeof(*absent));
absent->m = *instead;
absent->nxt = mc0;
absent->prev = mc0->prev;
mc0->prev = absent;
if (mc0->nxt == NULL)
mc0->nxt = absent;
}
/* write chain to mtemp */
mftmp = nfs_setmntent (MOUNTED_TEMP, "w");
if (mftmp == NULL || mftmp->mntent_fp == NULL) {
int errsv = errno;
nfs_error (_("cannot open %s (%s) - mtab not updated"),
MOUNTED_TEMP, strerror (errsv));
goto leave;
}
for (mc = mc0->nxt; mc && mc != mc0; mc = mc->nxt) {
if (nfs_addmntent(mftmp, &(mc->m)) == 1) {
int errsv = errno;
die (EX_FILEIO, _("error writing %s: %s"),
MOUNTED_TEMP, strerror (errsv));
}
}
#if 0
/* the chain might have strings copied from 'instead',
* so we cannot safely free it.
* And there is no need anyway because we are going to exit
* shortly. So just don't call discard_mntentchn....
*/
discard_mntentchn(mc0);
#endif
if (fchmod (fileno (mftmp->mntent_fp),
S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0) {
int errsv = errno;
nfs_error(_("%s: error changing mode of %s: %s"),
progname, MOUNTED_TEMP, strerror (errsv));
}
nfs_endmntent (mftmp);
{ /*
* If mount is setuid and some non-root user mounts sth,
* then mtab.tmp might get the group of this user. Copy uid/gid
* from the present mtab before renaming.
*/
struct stat sbuf;
if (stat (MOUNTED, &sbuf) == 0) {
if (chown (MOUNTED_TEMP, sbuf.st_uid, sbuf.st_gid) < 0) {
nfs_error(_("%s: error changing owner of %s: %s"),
progname, MOUNTED_TEMP, strerror (errno));
}
}
}
/* rename mtemp to mtab */
if (rename (MOUNTED_TEMP, MOUNTED) < 0) {
int errsv = errno;
nfs_error(_("%s: can't rename %s to %s: %s\n"),
progname, MOUNTED_TEMP, MOUNTED,
strerror(errsv));
}
leave:
unlock_mtab();
}
void
update_mtab (const char *dir, struct my_mntent *instead) {
mntFILE *mfp, *mftmp;
const char *fnam = MOUNTED;
struct mntentchn mtabhead; /* dummy */
struct mntentchn *mc, *mc0, *absent = NULL;
if (mtab_does_not_exist() || mtab_is_a_symlink())
return;
lock_mtab();
/* having locked mtab, read it again */
mc0 = mc = &mtabhead;
mc->nxt = mc->prev = NULL;
mfp = my_setmntent(fnam, "r");
if (mfp == NULL || mfp->mntent_fp == NULL) {
int errsv = errno;
error (_("cannot open %s (%s) - mtab not updated"),
fnam, strerror (errsv));
goto leave;
}
read_mntentchn(mfp, fnam, mc);
/* find last occurrence of dir */
for (mc = mc0->prev; mc && mc != mc0; mc = mc->prev)
if (streq(mc->m.mnt_dir, dir))
break;
if (mc && mc != mc0) {
if (instead == NULL) {
/* An umount - remove entry */
if (mc && mc != mc0) {
mc->prev->nxt = mc->nxt;
mc->nxt->prev = mc->prev;
free(mc);
}
} else {
/* A remount */
mc->m.mnt_opts = instead->mnt_opts;
}
} else if (instead) {
/* not found, add a new entry */
absent = xmalloc(sizeof(*absent));
absent->m = *instead;
absent->nxt = mc0;
absent->prev = mc0->prev;
mc0->prev = absent;
if (mc0->nxt == NULL)
mc0->nxt = absent;
}
/* write chain to mtemp */
mftmp = my_setmntent (MOUNTED_TEMP, "w");
if (mftmp == NULL || mftmp->mntent_fp == NULL) {
int errsv = errno;
error (_("cannot open %s (%s) - mtab not updated"),
MOUNTED_TEMP, strerror (errsv));
goto leave;
}
for (mc = mc0->nxt; mc && mc != mc0; mc = mc->nxt) {
if (my_addmntent(mftmp, &(mc->m)) == 1) {
int errsv = errno;
die (EX_FILEIO, _("error writing %s: %s"),
MOUNTED_TEMP, strerror (errsv));
}
}
discard_mntentchn(mc0);
if (fchmod (fileno (mftmp->mntent_fp),
S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0) {
int errsv = errno;
fprintf(stderr, _("error changing mode of %s: %s\n"),
MOUNTED_TEMP, strerror (errsv));
}
my_endmntent (mftmp);
{ /*
* If mount is setuid and some non-root user mounts sth,
* then mtab.tmp might get the group of this user. Copy uid/gid
* from the present mtab before renaming.
*/
struct stat sbuf;
if (stat (MOUNTED, &sbuf) == 0)
chown (MOUNTED_TEMP, sbuf.st_uid, sbuf.st_gid);
}
/* rename mtemp to mtab */
if (rename (MOUNTED_TEMP, MOUNTED) < 0) {
int errsv = errno;
fprintf(stderr, _("can't rename %s to %s: %s\n"),
MOUNTED_TEMP, MOUNTED, strerror(errsv));
}
leave:
unlock_mtab();
}
