Commit 8902dd52 authored by Paulo Alcantara (SUSE)'s avatar Paulo Alcantara (SUSE) Committed by David S. Miller
Browse files

init: Support mounting root file systems over SMB 



Add a new virtual device named /dev/cifs (0xfe) to tell the kernel to
mount the root file system over the network by using SMB protocol.

cifs_root_data() will be responsible to retrieve the parsed
information of the new command-line option (cifsroot=) and then call
do_mount_root() with the appropriate mount options for cifs.ko.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1f6d768a

init/do_mounts.c

+49 −0
Original line number Diff line number Diff line
@@ -212,6 +212,7 @@ static int match_dev_by_label(struct device *dev, const void *data) 
 *	   a colon.

 *	9) PARTLABEL=<name> with name being the GPT partition label.

 *	   MSDOS partitions do not support labels!

 *	10) /dev/cifs represents Root_CIFS (0xfe)

 *

 *	If name doesn't have fall into the categories above, we return (0,0).

 *	block_class is used to check if something is a disk name. If the disk
@@ -268,6 +269,9 @@ dev_t name_to_dev_t(const char *name) 
	res = Root_NFS;

	if (strcmp(name, "nfs") == 0)

		goto done;

	res = Root_CIFS;

	if (strcmp(name, "cifs") == 0)

		goto done;

	res = Root_RAM0;

	if (strcmp(name, "ram") == 0)

		goto done;
@@ -501,6 +505,42 @@ static int __init mount_nfs_root(void) 
}

#endif



#ifdef CONFIG_CIFS_ROOT



extern int cifs_root_data(char **dev, char **opts);



#define CIFSROOT_TIMEOUT_MIN	5

#define CIFSROOT_TIMEOUT_MAX	30

#define CIFSROOT_RETRY_MAX	5



static int __init mount_cifs_root(void)

{

	char *root_dev, *root_data;

	unsigned int timeout;

	int try, err;



	err = cifs_root_data(&root_dev, &root_data);

	if (err != 0)

		return 0;



	timeout = CIFSROOT_TIMEOUT_MIN;

	for (try = 1; ; try++) {

		err = do_mount_root(root_dev, "cifs", root_mountflags,

				    root_data);

		if (err == 0)

			return 1;

		if (try > CIFSROOT_RETRY_MAX)

			break;



		ssleep(timeout);

		timeout <<= 1;

		if (timeout > CIFSROOT_TIMEOUT_MAX)

			timeout = CIFSROOT_TIMEOUT_MAX;

	}

	return 0;

}

#endif



#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)

void __init change_floppy(char *fmt, ...)

{
@@ -542,6 +582,15 @@ void __init mount_root(void) 
		ROOT_DEV = Root_FD0;

	}

#endif

#ifdef CONFIG_CIFS_ROOT

	if (ROOT_DEV == Root_CIFS) {

		if (mount_cifs_root())

			return;



		printk(KERN_ERR "VFS: Unable to mount root fs via SMB, trying floppy.\n");

		ROOT_DEV = Root_FD0;

	}

#endif

#ifdef CONFIG_BLK_DEV_FD

	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {

		/* rd_doload is 2 for a dual initrd/ramload setup */

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