/*
* Ideally the mounted aufs should be unmounted even if its mntpnt has very long
* pathname. In other words, if umount.aufs cannot handle a long pathname, then
* mount.aufs should reject in the beginning.
* getmntent(3) in glibc reads 4096 bytes for a single mnt entry. I agree it is
* large enough. And mount(8) rejects too long pathname. It is OK too. As long
* as 4095 (4096 - 1) bytes pathname succeeds mounting, then it should be
* unmounted flawlessly.
* Testing on Debian v7 (wheezy) succeeded mounting 4095 bytes pathname, but
* failed unmounting. I don't like this unbalancing. So replace getmntent() by
* getmntent_r() with larger buffer. Obviously this is less important since such
* long pathname is very rare.
*/
int au_proc_getmntent(char *mntpnt, struct mntent *rent)
{
int found;
struct mntent *p, e;
FILE *fp;
char a[4096 + 1024], path[PATH_MAX], *decoded;
decoded = au_decode_mntpnt(mntpnt, path, sizeof(path));
if (!decoded)
AuFin("au_decode_mntpnt");
fp = setmntent(ProcMounts, "r");
if (!fp)
AuFin(ProcMounts);
/* find the last one */
memset(rent, 0, sizeof(*rent));
found = 0;
while ((p = getmntent_r(fp, &e, a, sizeof(a))))
if (!strcmp(p->mnt_dir, decoded)) {
Dpri("%s, %s, %s, %s, %d, %d\n",
p->mnt_fsname, p->mnt_dir, p->mnt_type,
p->mnt_opts, p->mnt_freq, p->mnt_passno);
copy_ent(rent, p);
found = 1;
}
endmntent(fp);
if (!found) {
errno = EINVAL;
AuFin("%s, %s", mntpnt, decoded);
}
return 0;
}
static int ftw_cpup(const char *fname, const struct stat *st, int flags,
struct FTW *ftw)
{
int err;
if (!strcmp(fname + ftw->base, AUFS_WH_PLINKDIR))
return FTW_SKIP_SUBTREE;
if (flags == FTW_D || flags == FTW_DNR)
return FTW_CONTINUE;
/*
* do nothing but update something harmless in order to make it copyup
*/
if (ia_test(st->st_ino)) {
Dpri("%s\n", fname);
if (!S_ISLNK(st->st_mode))
err = chown(fname, -1, -1);
else
err = lchown(fname, -1, -1);
if (err)
AuFin("%s", fname);
}
return FTW_CONTINUE;
}
int au_proc_getmntent(char *mntpnt, struct mntent *rent)
{
int found;
struct mntent *p;
FILE *fp;
fp = setmntent(ProcMounts, "r");
if (!fp)
AuFin(ProcMounts);
/* find the last one */
memset(rent, 0, sizeof(*rent));
found = 0;
while ((p = getmntent(fp)))
if (!strcmp(p->mnt_dir, mntpnt)) {
Dpri("%s, %s, %s, %s, %d, %d\n",
p->mnt_fsname, p->mnt_dir, p->mnt_type,
p->mnt_opts, p->mnt_freq, p->mnt_passno);
copy_ent(rent, p);
found = 1;
}
endmntent(fp);
if (!found) {
errno = EINVAL;
AuFin("%s", mntpnt);
}
return 0;
}
static int do_plink(char *cwd, int cmd, int nbr, char *br[])
{
int err, i, l;
struct rlimit rlim;
__nftw_func_t func;
char *p;
err = 0;
switch (cmd) {
case AuPlink_FLUSH:
/*FALLTHROUGH*/
case AuPlink_CPUP:
func = ftw_cpup;
break;
case AuPlink_LIST:
func = ftw_list;
break;
default:
errno = EINVAL;
AuFin(NULL);
func = NULL; /* never reach here */
}
for (i = 0; i < nbr; i++) {
//puts(br[i]);
p = strchr(br[i], '=');
if (strcmp(p + 1, AUFS_BRPERM_RW)
&& strcmp(p + 1, AUFS_BRPERM_RWNLWH))
continue;
*p = 0;
l = strlen(br[i]);
p = malloc(l + sizeof(AUFS_WH_PLINKDIR) + 2);
if (!p)
AuFin("malloc");
sprintf(p, "%s/%s", br[i], AUFS_WH_PLINKDIR);
//puts(p);
err = build_array(p);
if (err)
AuFin("build_array");
free(p);
}
if (!ia.nino)
goto out;
if (cmd == AuPlink_LIST) {
ia.p = ia.o;
for (i = 0; i < ia.nino; i++)
printf("%llu ", (unsigned long long)*ia.cur++);
putchar('\n');
}
err = getrlimit(RLIMIT_NOFILE, &rlim);
if (err)
AuFin("getrlimit");
nftw(cwd, func, rlim.rlim_cur - 10,
FTW_PHYS | FTW_MOUNT | FTW_ACTIONRETVAL);
/* ignore */
if (cmd == AuPlink_FLUSH) {
au_clean_plink();
na.cur = na.o;
for (i = 0; i < na.nname; i++) {
Dpri("%s\n", na.cur);
err = unlink(na.cur);
if (err)
AuFin("%s", na.cur);
na.cur += strlen(na.cur) + 1;
}
}
out:
free(ia.o);
free(na.o);
return err;
}