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-rw-r--r--package/aufs2-util/src/br.c172
1 files changed, 172 insertions, 0 deletions
diff --git a/package/aufs2-util/src/br.c b/package/aufs2-util/src/br.c
new file mode 100644
index 000000000..6451c120e
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+++ b/package/aufs2-util/src/br.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2005-2009 Junjiro Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define _GNU_SOURCE /* strndup */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <mntent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/aufs_type.h>
+#include "au_util.h"
+
+static int by_opts(char ***br, int *nbr, char *bropt)
+{
+ char *p, **a;
+ int l;
+
+ /* bropts is placed at the end of mnt_opts */
+ errno = EINVAL;
+ //puts(bropt);
+ if (strchr(bropt, ','))
+ AuFin("%s", bropt);
+
+ l = strlen(bropt);
+ p = malloc(l + 2);
+ if (!p)
+ AuFin("malloc");
+ memcpy(p, bropt, l + 1);
+ bropt = p;
+ bropt[l + 1] = 0; /* end marker */
+
+ *nbr = 1;
+ while (1) {
+ p = strchr(p + 1, ':');
+ if (!p)
+ break;
+ *p = 0;
+ (*nbr)++;
+ }
+
+ a = malloc(sizeof(a) * (*nbr + 1));
+ if (!a)
+ AuFin("malloc");
+
+ *br = a;
+ *a++ = bropt;
+ p = bropt;
+ while (*p) {
+ p += strlen(p) + 1;
+ *a++ = p;
+ }
+ *--a = NULL;
+ /* don't free bropt */
+
+ return 0;
+}
+
+#ifdef DEBUG
+#define SiPathPrefix "/tmp/aufs/si_"
+#define BufSiz 4
+#else
+#define SiPathPrefix "/sys/fs/aufs/si_"
+#define BufSiz BUFSIZ
+#endif
+
+static int by_sysfs(char ***br, int *nbr, char *siopt)
+{
+ int err, i, l, sz;
+ char buf[BufSiz], path[] = SiPathPrefix "1234567890123456/br32767";
+ char *p, *end, **a, *q;
+ FILE *fp;
+
+ errno = EINVAL;
+ end = strchr(siopt, ',');
+ if (end)
+ i = end - siopt;
+ else
+ i = strlen(siopt);
+
+ strncpy(path + sizeof(SiPathPrefix) - 1, siopt, i);
+ p = path + sizeof(SiPathPrefix) - 1 + i;
+ strcpy(p, "/br");
+ p += 3; /* "/br" */
+ *nbr = 0;
+ err = 0;
+ while (!err) {
+ sprintf(p, "%d", (*nbr)++);
+ err = access(path, F_OK);
+ }
+
+ a = malloc(sizeof(*br) * *nbr);
+ if (!a)
+ AuFin("malloc");
+
+ (*nbr)--;
+ *br = a;
+ for (i = 0; i < *nbr; i++) {
+ sprintf(p, "%d", i);
+ fp = fopen(path, "r");
+ if (!fp)
+ AuFin("%s", path);
+ if (fgets(buf, sizeof(buf), fp) != buf)
+ AuFin("%s", path);
+ l = strlen(buf);
+ if (l < 1)
+ AuFin("internal error, %d", l);
+
+ q = strndup(buf, l - 1);
+ if (buf[l - 1] != '\n') {
+ /* a branch path with crazy length */
+ /* stat(2) for sysfs is meaningless */
+ sz = sizeof(buf);
+ do {
+ free(q);
+ sz <<= 1;
+ q = malloc(sz);
+ if (!q)
+ AuFin("malloc");
+ rewind(fp);
+ if (fgets(q, sz, fp) != q)
+ AuFin("%s", path);
+ l = strlen(q);
+ } while (q[l - 1] != '\n');
+ q[l - 1] = 0;
+ }
+
+ *a++ = q;
+ /* don't free q */
+ fclose(fp); /* ignore */
+ }
+ *a = NULL;
+
+ return 0;
+}
+
+#define BrOpt ",br:"
+#define SiOpt "si"
+int au_br(char ***br, int *nbr, struct mntent *ent)
+{
+ char *p;
+
+ *nbr = 0;
+ p = strstr(ent->mnt_opts, BrOpt);
+ if (p)
+ return by_opts(br, nbr, p + sizeof(BrOpt) - 1);
+ p = hasmntopt(ent, SiOpt);
+ if (p)
+ return by_sysfs(br, nbr, p + sizeof(SiOpt));
+
+ /* broken opts */
+ AuFin("internal error, %s", ent->mnt_opts);
+ return -1; /* never reach here */
+}