int au_plink(char cwd[], int cmd, int begin_maint, int end_maint)
{
int err, nbr;
struct mntent ent;
char **br;
if (begin_maint)
au_plink_maint(cwd);
err = au_proc_getmntent(cwd, &ent);
if (err)
AuFin("no such mount point");
if (hasmntopt(&ent, "noplink"))
goto out; /* success */
#ifdef DEBUG
//char a[] = "a,b,br:/tmp/br0=rw:/br1=ro";
char a[] = "a,b,si=1,c";
ent.mnt_opts = a;
#endif
err = au_br(&br, &nbr, &ent);
//printf("nbr %d\n", nbr);
if (err)
AuFin(NULL);
err = do_plink(cwd, cmd, nbr, br);
if (err)
AuFin(NULL);
out:
if (end_maint)
au_plink_maint(NULL);
return err;
}
/* todo: there are some cases which options are not changed */
static void update_mtab(FILE *fp, char *mntpnt, int do_remount, int do_verbose)
{
int err;
long pos;
FILE *ofp;
struct mntent ent, *p;
/* prohibit updating mount options for this mntpnt */
au_plink_maint(mntpnt);
err = au_proc_getmntent(mntpnt, &ent);
if (err)
AuFin("no such mount point");
ofp = setmntent(MTab, "r");
if (!ofp)
AuFin(MTab);
if (do_remount) {
/* find the last one */
pos = -1;
while ((p = getmntent(ofp))) {
if (!strcmp(p->mnt_dir, mntpnt))
pos = ftell(ofp);
}
rewind(ofp);
if (pos > 0) {
while ((p = getmntent(ofp))) {
if (ftell(ofp) == pos) {
/* replace the line */
p = &ent;
pos = -1;
}
err = addmntent(fp, p);
if (err)
AuFin("addmntent");
}
if (pos > 0)
AuFin("internal error");
} else
append_mtab(fp, ofp, &ent);
} else
append_mtab(fp, ofp, &ent);
endmntent(ofp); /* ignore */
au_plink_maint(NULL);
if (do_verbose)
au_print_ent(&ent);
}
int si_write_lock(struct super_block *sb, int flags)
{
int err;
if (au_ftest_lock(flags, FLUSH))
au_nwt_flush(&au_sbi(sb)->si_nowait);
si_noflush_write_lock(sb);
err = au_plink_maint(sb, flags);
if (unlikely(err))
si_write_unlock(sb);
return err;
}
