Commit e2e694b9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull root filesystem type handling updates from Al Viro:
 "Teach init/do_mounts.c to handle non-block filesystems, hopefully
  preventing even more special-cased kludges (such as root=/dev/nfs,
  etc)"

* 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: simplify get_filesystem_list / get_all_fs_names
  init: allow mounting arbitrary non-blockdevice filesystems as root
  init: split get_fs_names
parents 7b7699c0 6e7c1770

fs/filesystems.c

+17 −10
Original line number Diff line number Diff line
@@ -209,21 +209,28 @@ SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2) 
}

#endif



int __init get_filesystem_list(char *buf)

int __init list_bdev_fs_names(char *buf, size_t size)

{

	int len = 0;

	struct file_system_type * tmp;

	struct file_system_type *p;

	size_t len;

	int count = 0;



	read_lock(&file_systems_lock);

	tmp = file_systems;

	while (tmp && len < PAGE_SIZE - 80) {

		len += sprintf(buf+len, "%s\t%s\n",

			(tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev",

			tmp->name);

		tmp = tmp->next;

	for (p = file_systems; p; p = p->next) {

		if (!(p->fs_flags & FS_REQUIRES_DEV))

			continue;

		len = strlen(p->name) + 1;

		if (len > size) {

			pr_warn("%s: truncating file system list\n", __func__);

			break;

		}

		memcpy(buf, p->name, len);

		buf += len;

		size -= len;

		count++;

	}

	read_unlock(&file_systems_lock);

	return len;

	return count;

}



#ifdef CONFIG_PROC_FS

include/linux/fs.h

+1 −1
Original line number Diff line number Diff line
@@ -3592,7 +3592,7 @@ int proc_nr_dentry(struct ctl_table *table, int write, 
		  void *buffer, size_t *lenp, loff_t *ppos);

int proc_nr_inodes(struct ctl_table *table, int write,

		   void *buffer, size_t *lenp, loff_t *ppos);

int __init get_filesystem_list(char *buf);

int __init list_bdev_fs_names(char *buf, size_t size);



#define __FMODE_EXEC		((__force int) FMODE_EXEC)

#define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)

init/do_mounts.c

+65 −25
Original line number Diff line number Diff line
@@ -338,31 +338,22 @@ __setup("rootflags=", root_data_setup); 
__setup("rootfstype=", fs_names_setup);

__setup("rootdelay=", root_delay_setup);



static void __init get_fs_names(char *page)

static int __init split_fs_names(char *page, char *names)

{

	char *s = page;

	int count = 0;

	char *p = page;



	if (root_fs_names) {

		strcpy(page, root_fs_names);

		while (*s++) {

			if (s[-1] == ',')

				s[-1] = '\0';

	strcpy(p, root_fs_names);

	while (*p++) {

		if (p[-1] == ',')

			p[-1] = '\0';

	}

	} else {

		int len = get_filesystem_list(page);

		char *p, *next;

	*p = '\0';



		page[len] = '\0';

		for (p = page-1; p; p = next) {

			next = strchr(++p, '\n');

			if (*p++ != '\t')

				continue;

			while ((*s++ = *p++) != '\n')

				;

			s[-1] = '\0';

		}

	}

	*s = '\0';

	for (p = page; *p; p += strlen(p)+1)

		count++;



	return count;

}



static int __init do_mount_root(const char *name, const char *fs,
@@ -408,12 +399,16 @@ void __init mount_block_root(char *name, int flags) 
	char *fs_names = page_address(page);

	char *p;

	char b[BDEVNAME_SIZE];

	int num_fs, i;



	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",

		  MAJOR(ROOT_DEV), MINOR(ROOT_DEV));

	get_fs_names(fs_names);

	if (root_fs_names)

		num_fs = split_fs_names(fs_names, root_fs_names);

	else

		num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);

retry:

	for (p = fs_names; *p; p += strlen(p)+1) {

	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {

		int err = do_mount_root(name, p, flags, root_mount_data);

		switch (err) {

			case 0:
@@ -442,7 +437,7 @@ void __init mount_block_root(char *name, int flags) 
	printk("List of all partitions:\n");

	printk_all_partitions();

	printk("No filesystem could mount root, tried: ");

	for (p = fs_names; *p; p += strlen(p)+1)

	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)

		printk(" %s", p);

	printk("\n");

	panic("VFS: Unable to mount root fs on %s", b);
@@ -526,6 +521,47 @@ static int __init mount_cifs_root(void) 
}

#endif



static bool __init fs_is_nodev(char *fstype)

{

	struct file_system_type *fs = get_fs_type(fstype);

	bool ret = false;



	if (fs) {

		ret = !(fs->fs_flags & FS_REQUIRES_DEV);

		put_filesystem(fs);

	}



	return ret;

}



static int __init mount_nodev_root(void)

{

	char *fs_names, *fstype;

	int err = -EINVAL;

	int num_fs, i;



	fs_names = (void *)__get_free_page(GFP_KERNEL);

	if (!fs_names)

		return -EINVAL;

	num_fs = split_fs_names(fs_names, root_fs_names);



	for (i = 0, fstype = fs_names; i < num_fs;

	     i++, fstype += strlen(fstype) + 1) {

		if (!fs_is_nodev(fstype))

			continue;

		err = do_mount_root(root_device_name, fstype, root_mountflags,

				    root_mount_data);

		if (!err)

			break;

		if (err != -EACCES && err != -EINVAL)

			panic("VFS: Unable to mount root \"%s\" (%s), err=%d\n",

			      root_device_name, fstype, err);

	}



	free_page((unsigned long)fs_names);

	return err;

}



void __init mount_root(void)

{

#ifdef CONFIG_ROOT_NFS
@@ -542,6 +578,10 @@ void __init mount_root(void) 
		return;

	}

#endif

	if (ROOT_DEV == 0 && root_device_name && root_fs_names) {

		if (mount_nodev_root() == 0)

			return;

	}

#ifdef CONFIG_BLOCK

	{

		int err = create_dev("/dev/root", ROOT_DEV);