usr/kinit/do_mounts.c

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <alloca.h>
#include <inttypes.h>

#include "do_mounts.h"
#include "kinit.h"
#include "fstype.h"
#include "zlib.h"

/* Create the device node "name" */
int create_dev(const char *name, dev_t dev)
{
	unlink(name);
	return mknod(name, S_IFBLK | 0600, dev);
}

/* mount a filesystem, possibly trying a set of different types */
const char *mount_block(const char *source, const char *target,
			const char *type, unsigned long flags,
			const void *data)
{
	char *fslist, *p, *ep;
	const char *rp;
	ssize_t fsbytes;
	int fd;

	if (type) {
		dprintf("kinit: trying to mount %s on %s with type %s\n",
			source, target, type);
		int rv = mount(source, target, type, flags, data);
		/* Mount readonly if necessary */
		if (rv == -1 && errno == EACCES && !(flags & MS_RDONLY))
			rv = mount(source, target, type, flags | MS_RDONLY,
				   data);
		return rv ? NULL : type;
	}

	/* If no type given, try to identify the type first; this
	   also takes care of specific ordering requirements, like
	   ext3 before ext2... */
	fd = open(source, O_RDONLY);
	if (fd >= 0) {
		int err = identify_fs(fd, &type, NULL, 0);
		close(fd);

		if (!err && type) {
			dprintf("kinit: %s appears to be a %s filesystem\n",
				source, type);
			type = mount_block(source, target, type, flags, data);
			if (type)
				return type;
		}
	}

	dprintf("kinit: failed to identify filesystem %s, trying all\n",
		source);

	fsbytes = readfile("/proc/filesystems", &fslist);

	errno = EINVAL;
	if (fsbytes < 0)
		return NULL;

	p = fslist;
	ep = fslist + fsbytes;

	rp = NULL;

	while (p < ep) {
		type = p;
		p = strchr(p, '\n');
		if (!p)
			break;
		*p++ = '\0';
		if (*type != '\t')	/* We can't mount a block device as a "nodev" fs */
			continue;

		type++;
		rp = mount_block(source, target, type, flags, data);
		if (rp)
			break;
		if (errno != EINVAL)
			break;
	}

	free(fslist);
	return rp;
}

/* mount the root filesystem from a block device */
static int
mount_block_root(int argc, char *argv[], dev_t root_dev,
		 const char *type, unsigned long flags)
{
	const char *data, *rp;

	data = get_arg(argc, argv, "rootflags=");
	create_dev("/dev/root", root_dev);

	errno = 0;

	if (type) {
		if ((rp = mount_block("/dev/root", "/root", type, flags, data)))
			goto ok;
		if (errno != EINVAL)
			goto bad;
	}

	if (!errno
	    && (rp = mount_block("/dev/root", "/root", NULL, flags, data)))
		goto ok;

      bad:
	if (errno != EINVAL) {
		/*
		 * Allow the user to distinguish between failed open
		 * and bad superblock on root device.
		 */
		fprintf(stderr, "%s: Cannot open root device %s\n",
			progname, bdevname(root_dev));
		return -errno;
	} else {
		fprintf(stderr, "%s: Unable to mount root fs on device %s\n",
			progname, bdevname(root_dev));
		return -ESRCH;
	}

      ok:
	printf("%s: Mounted root (%s filesystem)%s.\n",
	       progname, rp, (flags & MS_RDONLY) ? " readonly" : "");
	return 0;
}

static int
mount_roots(int argc, char *argv[], const char *root_dev_name)
{
	char *roots = strdup(root_dev_name);
	char *root;
	const char *sep = ",";
	char *saveptr;
	int ret = -ESRCH;

	root = strtok_r(roots, sep, &saveptr);
	while (root) {
		dev_t root_dev;

		dprintf("kinit: trying to mount %s\n", root);
		root_dev = name_to_dev_t(root);
		ret = mount_root(argc, argv, root_dev, root);
		if (!ret)
			break;
		root = strtok_r(NULL, sep, &saveptr);
	}
	free(roots);
	return ret;
}

int
mount_root(int argc, char *argv[], dev_t root_dev, const char *root_dev_name)
{
	unsigned long flags = MS_RDONLY | MS_VERBOSE;
	int ret;
	const char *type = get_arg(argc, argv, "rootfstype=");

	if (get_flag(argc, argv, "rw") > get_flag(argc, argv, "ro")) {
		dprintf("kinit: mounting root rw\n");
		flags &= ~MS_RDONLY;
	}

	if (type) {
		if (!strcmp(type, "nfs"))
			root_dev = Root_NFS;
		else if (!strcmp(type, "jffs2") && !major(root_dev))
			root_dev = Root_MTD;
	}

	switch (root_dev) {
	case Root_NFS:
		ret = mount_nfs_root(argc, argv, flags);
		break;
	case Root_MTD:
		ret = mount_mtd_root(argc, argv, root_dev_name, type, flags);
		break;
	default:
		ret = mount_block_root(argc, argv, root_dev, type, flags);
		break;
	}

	if (!ret)
		chdir("/root");

	return ret;
}

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;

	dprintf("kinit: do_mounts\n");

	if (root_delay) {
		int delay = atoi(root_delay);
		fprintf(stderr, "Waiting %d s before mounting root device...\n",
			delay);
		sleep(delay);
	}

	md_run(argc, argv);

	if (root_dev_name) {
		root_dev = name_to_dev_t(root_dev_name);
	} else if (get_arg(argc, argv, "nfsroot=") ||
		   get_arg(argc, argv, "nfsaddrs=")) {
		root_dev = Root_NFS;
	} else {
		long rootdev;
		getintfile("/proc/sys/kernel/real-root-dev", &rootdev);
		root_dev = (dev_t) rootdev;
	}

	dprintf("kinit: root_dev = %s\n", bdevname(root_dev));

	if (initrd_load(argc, argv, root_dev)) {
		dprintf("initrd loaded\n");
		return 0;
	}

	if (load_ramdisk && atoi(load_ramdisk)) {
		if (ramdisk_load(argc, argv))
			root_dev = Root_RAM0;
	}

	if (root_dev == Root_MULTI)
		return mount_roots(argc, argv, root_dev_name);
	return mount_root(argc, argv, root_dev, root_dev_name);
}
1	niro	532	#include <ctype.h>
2			#include <errno.h>
3			#include <fcntl.h>
4			#include <sys/mount.h>
5			#include <sys/stat.h>
6			#include <stdio.h>
7			#include <stdlib.h>
8			#include <string.h>
9			#include <unistd.h>
10			#include <alloca.h>
11			#include <inttypes.h>
12
13			#include "do_mounts.h"
14			#include "kinit.h"
15			#include "fstype.h"
16			#include "zlib.h"
17
18			/* Create the device node "name" */
19			int create_dev(const char *name, dev_t dev)
20			{
21			unlink(name);
22			return mknod(name, S_IFBLK \| 0600, dev);
23			}
24
25			/* mount a filesystem, possibly trying a set of different types */
26			const char mount_block(const char source, const char *target,
27			const char *type, unsigned long flags,
28			const void *data)
29			{
30			char fslist, p, *ep;
31			const char *rp;
32			ssize_t fsbytes;
33			int fd;
34
35			if (type) {
36	niro	1122	dprintf("kinit: trying to mount %s on %s with type %s\n",
37			source, target, type);
38	niro	532	int rv = mount(source, target, type, flags, data);
39			/* Mount readonly if necessary */
40			if (rv == -1 && errno == EACCES && !(flags & MS_RDONLY))
41			rv = mount(source, target, type, flags \| MS_RDONLY,
42			data);
43			return rv ? NULL : type;
44			}
45
46			/* If no type given, try to identify the type first; this
47			also takes care of specific ordering requirements, like
48			ext3 before ext2... */
49			fd = open(source, O_RDONLY);
50			if (fd >= 0) {
51			int err = identify_fs(fd, &type, NULL, 0);
52			close(fd);
53
54			if (!err && type) {
55	niro	1122	dprintf("kinit: %s appears to be a %s filesystem\n",
56			source, type);
57	niro	532	type = mount_block(source, target, type, flags, data);
58			if (type)
59			return type;
60			}
61			}
62
63	niro	1122	dprintf("kinit: failed to identify filesystem %s, trying all\n",
64			source);
65	niro	532
66			fsbytes = readfile("/proc/filesystems", &fslist);
67
68			errno = EINVAL;
69			if (fsbytes < 0)
70			return NULL;
71
72			p = fslist;
73			ep = fslist + fsbytes;
74
75			rp = NULL;
76
77			while (p < ep) {
78			type = p;
79			p = strchr(p, '\n');
80			if (!p)
81			break;
82			*p++ = '\0';
83			if (type != '\t') / We can't mount a block device as a "nodev" fs */
84			continue;
85
86			type++;
87			rp = mount_block(source, target, type, flags, data);
88			if (rp)
89			break;
90			if (errno != EINVAL)
91			break;
92			}
93
94			free(fslist);
95			return rp;
96			}
97
98			/* mount the root filesystem from a block device */
99			static int
100			mount_block_root(int argc, char *argv[], dev_t root_dev,
101			const char *type, unsigned long flags)
102			{
103			const char data, rp;
104
105			data = get_arg(argc, argv, "rootflags=");
106			create_dev("/dev/root", root_dev);
107
108			errno = 0;
109
110			if (type) {
111			if ((rp = mount_block("/dev/root", "/root", type, flags, data)))
112			goto ok;
113			if (errno != EINVAL)
114			goto bad;
115			}
116
117			if (!errno
118			&& (rp = mount_block("/dev/root", "/root", NULL, flags, data)))
119			goto ok;
120
121			bad:
122			if (errno != EINVAL) {
123			/*
124			* Allow the user to distinguish between failed open
125			* and bad superblock on root device.
126			*/
127			fprintf(stderr, "%s: Cannot open root device %s\n",
128			progname, bdevname(root_dev));
129			return -errno;
130			} else {
131			fprintf(stderr, "%s: Unable to mount root fs on device %s\n",
132			progname, bdevname(root_dev));
133			return -ESRCH;
134			}
135
136			ok:
137			printf("%s: Mounted root (%s filesystem)%s.\n",
138			progname, rp, (flags & MS_RDONLY) ? " readonly" : "");
139			return 0;
140			}
141
142	niro	1122	static int
143			mount_roots(int argc, char argv[], const char root_dev_name)
144			{
145			char *roots = strdup(root_dev_name);
146			char *root;
147			const char *sep = ",";
148			char *saveptr;
149			int ret = -ESRCH;
150
151			root = strtok_r(roots, sep, &saveptr);
152			while (root) {
153			dev_t root_dev;
154
155			dprintf("kinit: trying to mount %s\n", root);
156			root_dev = name_to_dev_t(root);
157			ret = mount_root(argc, argv, root_dev, root);
158			if (!ret)
159			break;
160			root = strtok_r(NULL, sep, &saveptr);
161			}
162			free(roots);
163			return ret;
164			}
165
166	niro	532	int
167			mount_root(int argc, char argv[], dev_t root_dev, const char root_dev_name)
168			{
169			unsigned long flags = MS_RDONLY \| MS_VERBOSE;
170			int ret;
171			const char *type = get_arg(argc, argv, "rootfstype=");
172
173			if (get_flag(argc, argv, "rw") > get_flag(argc, argv, "ro")) {
174	niro	1122	dprintf("kinit: mounting root rw\n");
175	niro	532	flags &= ~MS_RDONLY;
176			}
177
178			if (type) {
179			if (!strcmp(type, "nfs"))
180			root_dev = Root_NFS;
181			else if (!strcmp(type, "jffs2") && !major(root_dev))
182			root_dev = Root_MTD;
183			}
184
185			switch (root_dev) {
186			case Root_NFS:
187			ret = mount_nfs_root(argc, argv, flags);
188			break;
189			case Root_MTD:
190			ret = mount_mtd_root(argc, argv, root_dev_name, type, flags);
191			break;
192			default:
193			ret = mount_block_root(argc, argv, root_dev, type, flags);
194			break;
195			}
196
197			if (!ret)
198			chdir("/root");
199
200			return ret;
201			}
202
203			int do_mounts(int argc, char *argv[])
204			{
205			const char *root_dev_name = get_arg(argc, argv, "root=");
206			const char *root_delay = get_arg(argc, argv, "rootdelay=");
207			const char *load_ramdisk = get_arg(argc, argv, "load_ramdisk=");
208			dev_t root_dev = 0;
209
210	niro	1122	dprintf("kinit: do_mounts\n");
211	niro	532
212			if (root_delay) {
213			int delay = atoi(root_delay);
214			fprintf(stderr, "Waiting %d s before mounting root device...\n",
215			delay);
216			sleep(delay);
217			}
218
219			md_run(argc, argv);
220
221			if (root_dev_name) {
222			root_dev = name_to_dev_t(root_dev_name);
223			} else if (get_arg(argc, argv, "nfsroot=") \|\|
224			get_arg(argc, argv, "nfsaddrs=")) {
225			root_dev = Root_NFS;
226			} else {
227			long rootdev;
228			getintfile("/proc/sys/kernel/real-root-dev", &rootdev);
229			root_dev = (dev_t) rootdev;
230			}
231
232	niro	1122	dprintf("kinit: root_dev = %s\n", bdevname(root_dev));
233	niro	532
234			if (initrd_load(argc, argv, root_dev)) {
235	niro	1122	dprintf("initrd loaded\n");
236	niro	532	return 0;
237			}
238
239			if (load_ramdisk && atoi(load_ramdisk)) {
240	niro	1122	if (ramdisk_load(argc, argv))
241	niro	532	root_dev = Root_RAM0;
242			}
243
244	niro	1122	if (root_dev == Root_MULTI)
245			return mount_roots(argc, argv, root_dev_name);
246	niro	532	return mount_root(argc, argv, root_dev, root_dev_name);
247			}