Commit 56463e50 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust

NFS: Use super.c for NFSROOT mount option parsing

Replace duplicate code in NFSROOT for mounting an NFS server on '/'
with logic that uses the existing mainline text-based logic in the NFS
client.

Add documenting comments where appropriate.

Note that this means NFSROOT mounts now use the same default settings
as v2/v3 mounts done via mount(2) from user space.

  vers=3,tcp,rsize=<negotiated default>,wsize=<negotiated default>

As before, however, no version/protocol negotiation with the server is
done.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 60ac0368
......@@ -3,9 +3,10 @@
*
* Allow an NFS filesystem to be mounted as root. The way this works is:
* (1) Use the IP autoconfig mechanism to set local IP addresses and routes.
* (2) Handle RPC negotiation with the system which replied to RARP or
* was reported as a boot server by BOOTP or manually.
* (3) The actual mounting is done later, when init() is running.
* (2) Construct the device string and the options string using DHCP
* option 17 and/or kernel command line options.
* (3) When mount_root() sets up the root file system, pass these strings
* to the NFS client's regular mount interface via sys_mount().
*
*
* Changes:
......@@ -65,7 +66,8 @@
* Hua Qin : Support for mounting root file system via
* NFS over TCP.
* Fabian Frederick: Option parser rebuilt (using parser lib)
*/
* Chuck Lever : Use super.c's text-based mount option parsing
*/
#include <linux/types.h>
#include <linux/string.h>
......@@ -101,11 +103,17 @@
/* Parameters passed from the kernel command line */
static char nfs_root_parms[256] __initdata = "";
/* Text-based mount options passed to super.c */
static char nfs_root_options[256] __initdata = "";
/* Address of NFS server */
static __be32 servaddr __initdata = 0;
/* Name of directory to mount */
static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = { 0, };
static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = "";
/* server:export path string passed to super.c */
static char nfs_root_device[NFS_MAXPATHLEN + 1] __initdata = "";
/* NFS-related data */
static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */
......@@ -537,7 +545,7 @@ static int __init root_nfs_get_handle(void)
* Get the NFS port numbers and file handle, and return the prepared 'data'
* argument for mount() if everything went OK. Return NULL otherwise.
*/
void * __init nfs_root_data(void)
void * __init old_nfs_root_data(void)
{
if (root_nfs_init() < 0
|| root_nfs_ports() < 0
......@@ -546,3 +554,165 @@ void * __init nfs_root_data(void)
set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port));
return (void*)&nfs_data;
}
static int __init root_nfs_copy(char *dest, const char *src,
const size_t destlen)
{
if (strlcpy(dest, src, destlen) > destlen)
return -1;
return 0;
}
static int __init root_nfs_cat(char *dest, const char *src,
const size_t destlen)
{
if (strlcat(dest, src, destlen) > destlen)
return -1;
return 0;
}
/*
* Parse out root export path and mount options from
* passed-in string @incoming.
*
* Copy the export path into @exppath.
*/
static int __init root_nfs_parse_options(char *incoming, char *exppath,
const size_t exppathlen)
{
char *p;
/*
* Set the NFS remote path
*/
p = strsep(&incoming, ",");
if (*p != '\0' && strcmp(p, "default") != 0)
if (root_nfs_copy(exppath, p, exppathlen))
return -1;
/*
* @incoming now points to the rest of the string; if it
* contains something, append it to our root options buffer
*/
if (incoming != NULL && *incoming != '\0')
if (root_nfs_cat(nfs_root_options, incoming,
sizeof(nfs_root_options)))
return -1;
/*
* Possibly prepare for more options to be appended
*/
if (nfs_root_options[0] != '\0' &&
nfs_root_options[strlen(nfs_root_options)] != ',')
if (root_nfs_cat(nfs_root_options, ",",
sizeof(nfs_root_options)))
return -1;
return 0;
}
/*
* Decode the export directory path name and NFS options from
* the kernel command line. This has to be done late in order to
* use a dynamically acquired client IP address for the remote
* root directory path.
*
* Returns zero if successful; otherwise -1 is returned.
*/
static int __init root_nfs_data(char *cmdline)
{
char addr_option[sizeof("nolock,addr=") + INET_ADDRSTRLEN + 1];
int len, retval = -1;
char *tmp = NULL;
const size_t tmplen = sizeof(nfs_export_path);
tmp = kzalloc(tmplen, GFP_KERNEL);
if (tmp == NULL)
goto out_nomem;
strcpy(tmp, NFS_ROOT);
if (root_server_path[0] != '\0') {
dprintk("Root-NFS: DHCPv4 option 17: %s\n",
root_server_path);
if (root_nfs_parse_options(root_server_path, tmp, tmplen))
goto out_optionstoolong;
}
if (cmdline[0] != '\0') {
dprintk("Root-NFS: nfsroot=%s\n", cmdline);
if (root_nfs_parse_options(cmdline, tmp, tmplen))
goto out_optionstoolong;
}
/*
* Append mandatory options for nfsroot so they override
* what has come before
*/
snprintf(addr_option, sizeof(addr_option), "nolock,addr=%pI4",
&servaddr);
if (root_nfs_cat(nfs_root_options, addr_option,
sizeof(nfs_root_options)))
goto out_optionstoolong;
/*
* Set up nfs_root_device. For NFS mounts, this looks like
*
* server:/path
*
* At this point, utsname()->nodename contains our local
* IP address or hostname, set by ipconfig. If "%s" exists
* in tmp, substitute the nodename, then shovel the whole
* mess into nfs_root_device.
*/
len = snprintf(nfs_export_path, sizeof(nfs_export_path),
tmp, utsname()->nodename);
if (len > (int)sizeof(nfs_export_path))
goto out_devnametoolong;
len = snprintf(nfs_root_device, sizeof(nfs_root_device),
"%pI4:%s", &servaddr, nfs_export_path);
if (len > (int)sizeof(nfs_root_device))
goto out_devnametoolong;
retval = 0;
out:
kfree(tmp);
return retval;
out_nomem:
printk(KERN_ERR "Root-NFS: could not allocate memory\n");
goto out;
out_optionstoolong:
printk(KERN_ERR "Root-NFS: mount options string too long\n");
goto out;
out_devnametoolong:
printk(KERN_ERR "Root-NFS: root device name too long.\n");
goto out;
}
/**
* nfs_root_data - Return prepared 'data' for NFSROOT mount
* @root_device: OUT: address of string containing NFSROOT device
* @root_data: OUT: address of string containing NFSROOT mount options
*
* Returns zero and sets @root_device and @root_data if successful,
* otherwise -1 is returned.
*/
int __init nfs_root_data(char **root_device, char **root_data)
{
#ifdef NFSROOT_DEBUG
nfs_debug |= NFSDBG_ROOT | NFSDBG_MOUNT;
#endif /* NFSROOT_DEBUG */
servaddr = root_server_addr;
if (servaddr == htonl(INADDR_NONE)) {
printk(KERN_ERR "Root-NFS: no NFS server address\n");
return -1;
}
if (root_nfs_data(nfs_root_parms) < 0)
return -1;
*root_device = nfs_root_device;
*root_data = nfs_root_options;
return 0;
}
......@@ -364,6 +364,7 @@ extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ct
extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
extern u64 nfs_compat_user_ino64(u64 fileid);
extern void nfs_fattr_init(struct nfs_fattr *fattr);
extern unsigned long nfs_inc_attr_generation_counter(void);
extern struct nfs_fattr *nfs_alloc_fattr(void);
......@@ -379,9 +380,12 @@ static inline void nfs_free_fhandle(const struct nfs_fh *fh)
kfree(fh);
}
/*
* linux/fs/nfs/nfsroot.c
*/
extern int nfs_root_data(char **root_device, char **root_data); /*__init*/
/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
extern __be32 root_nfs_parse_addr(char *name); /*__init*/
extern unsigned long nfs_inc_attr_generation_counter(void);
/*
* linux/fs/nfs/file.c
......@@ -584,10 +588,6 @@ nfs_fileid_to_ino_t(u64 fileid)
return ino;
}
/* NFS root */
extern void * nfs_root_data(void);
#define nfs_wait_event(clnt, wq, condition) \
({ \
int __retval = wait_event_killable(wq, condition); \
......
......@@ -291,13 +291,13 @@ void __init mount_block_root(char *name, int flags)
#ifdef CONFIG_ROOT_NFS
static int __init mount_nfs_root(void)
{
void *data = nfs_root_data();
char *root_dev, *root_data;
create_dev("/dev/root", ROOT_DEV);
if (data &&
do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
return 1;
if (nfs_root_data(&root_dev, &root_data) != 0)
return 0;
if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0)
return 0;
return 1;
}
#endif
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment