[klibc] [PATCH] kinit: Add ability to mount filesystems via /etc/fstab or cmdline
San Mehat
san at google.com
Tue Nov 22 10:57:31 PST 2011
This patch adds the ability to mount filesystems via an embedded fstab
or via the kernel command line.
When using the kernel command-line, the following format is required:
'kinit_mount=<fs_name>;<fs_dir>;<fs_type>;<fs_opts>'
Multiple mount options can be specified; they are evaluated in the order
they appear in the command-line.
Signed-off-by: San Mehat <san at google.com>
---
Things I'd like to change:
- Move string option parsing into mount_block()
- ro, bind
- Handle bind mounts in /etc/fstab entries
---
usr/kinit/do_mounts.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 104 insertions(+), 2 deletions(-)
diff --git a/usr/kinit/do_mounts.c b/usr/kinit/do_mounts.c
index 3ffac91..5d36385 100644
--- a/usr/kinit/do_mounts.c
+++ b/usr/kinit/do_mounts.c
@@ -7,6 +7,7 @@
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
+#include <mntent.h>
#include "do_mounts.h"
#include "kinit.h"
@@ -199,12 +200,97 @@ mount_root(int argc, char *argv[], dev_t root_dev, const char *root_dev_name)
return ret;
}
+int do_cmdline_mounts(int argc, char *argv[])
+{
+ int arg_i;
+
+ for (arg_i = 0; arg_i < argc; arg_i++) {
+ const char *fs_name, *fs_dir, *fs_type;
+ char *fs_opts;
+ unsigned long flags = 0;
+ char new_fs_opts[128] = { 0 };
+ char *saveptr = NULL;
+ char *fs_opts_savedptr = NULL;
+ int opt_first = 1;
+ const char *opt;
+
+ if (strncmp(argv[arg_i], "kinit_mount=", 12))
+ continue;
+ /*
+ * Format:
+ * <fs_name>;<dir>;<fs_type>;[opt1],[optn...]
+ */
+ fs_name = strtok_r(&argv[arg_i][12], ";", &saveptr);
+ if (!fs_name) {
+ fprintf(stderr, "Failed to parse fs_name\n");
+ continue;
+ }
+ fs_dir = strtok_r(NULL, ";", &saveptr);
+ if (!fs_dir) {
+ fprintf(stderr, "Failed to parse fs_dir\n");
+ continue;
+ }
+ fs_type = strtok_r(NULL, ";", &saveptr);
+ if (!fs_type) {
+ fprintf(stderr, "Failed to parse fs_type\n");
+ continue;
+ }
+ fs_opts = strtok_r(NULL, ";", &saveptr);
+ if (!fs_opts) {
+ fprintf(stderr, "Failed to parse fs_opts\n");
+ continue;
+ }
+
+ /* If 'fs_opts' specifies 'ro' or 'bind', gobble it up. */
+ while ((opt = strtok_r((opt_first ? fs_opts : NULL),
+ ",", &fs_opts_savedptr))) {
+ if (!strcmp(opt, "ro"))
+ flags |= MS_RDONLY;
+ else if (!strcmp(opt, "bind"))
+ flags |= MS_BIND;
+ else {
+ if (!opt_first)
+ strcat(new_fs_opts, ",");
+ strcat(new_fs_opts, opt);
+ }
+ if (opt_first)
+ opt_first = 0;
+ }
+
+ if (!mount_block(fs_name, fs_dir, fs_type,
+ flags, new_fs_opts)) {
+ fprintf(stderr, "Skipping failed mount '%s'\n",
+ fs_name);
+ }
+ }
+ return 0;
+}
+
+int do_fstab_mounts(FILE *fp)
+{
+ struct mntent *ent = NULL;
+
+ while ((ent = getmntent(fp))) {
+ if (!mount_block(ent->mnt_fsname,
+ ent->mnt_dir,
+ ent->mnt_type,
+ 0,
+ ent->mnt_opts)) {
+ fprintf(stderr, "Skipping failed mount '%s'\n",
+ ent->mnt_fsname);
+ }
+ }
+ return 0;
+}
+
int do_mounts(int argc, char *argv[])
{
const char *root_dev_name = get_arg(argc, argv, "root=");
const char *root_delay = get_arg(argc, argv, "rootdelay=");
const char *load_ramdisk = get_arg(argc, argv, "load_ramdisk=");
dev_t root_dev = 0;
+ int err;
+ FILE *fp;
dprintf("kinit: do_mounts\n");
@@ -241,6 +327,22 @@ int do_mounts(int argc, char *argv[])
}
if (root_dev == Root_MULTI)
- return mount_roots(argc, argv, root_dev_name);
- return mount_root(argc, argv, root_dev, root_dev_name);
+ err = mount_roots(argc, argv, root_dev_name);
+ else
+ err = mount_root(argc, argv, root_dev, root_dev_name);
+
+ if (err)
+ return err;
+
+ if ((fp = fopen("/etc/fstab", "r"))) {
+ err = do_fstab_mounts(fp);
+ fclose(fp);
+ }
+
+ if (err)
+ return err;
+
+ if (get_arg(argc, argv, "kinit_mount="))
+ err = do_cmdline_mounts(argc, argv);
+ return err;
}
--
1.7.3.1
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