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Diffstat (limited to 'package/aufs2-util/src/br.c')
| -rw-r--r-- | package/aufs2-util/src/br.c | 172 |
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 --- /dev/null +++ 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 */ +} |