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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/nfs/nfsroot.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/nfs/nfsroot.c')
-rw-r--r-- | fs/nfs/nfsroot.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c new file mode 100644 index 000000000000..fd5bc596fe8a --- /dev/null +++ b/fs/nfs/nfsroot.c @@ -0,0 +1,513 @@ +/* + * $Id: nfsroot.c,v 1.45 1998/03/07 10:44:46 mj Exp $ + * + * Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de> + * + * 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. + * + * + * Changes: + * + * Alan Cox : Removed get_address name clash with FPU. + * Alan Cox : Reformatted a bit. + * Gero Kuhlmann : Code cleanup + * Michael Rausch : Fixed recognition of an incoming RARP answer. + * Martin Mares : (2.0) Auto-configuration via BOOTP supported. + * Martin Mares : Manual selection of interface & BOOTP/RARP. + * Martin Mares : Using network routes instead of host routes, + * allowing the default configuration to be used + * for normal operation of the host. + * Martin Mares : Randomized timer with exponential backoff + * installed to minimize network congestion. + * Martin Mares : Code cleanup. + * Martin Mares : (2.1) BOOTP and RARP made configuration options. + * Martin Mares : Server hostname generation fixed. + * Gerd Knorr : Fixed wired inode handling + * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored. + * Martin Mares : RARP replies not tested for server address. + * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please + * send me your new patches _before_ bothering + * Linus so that I don' always have to cleanup + * _afterwards_ - thanks) + * Gero Kuhlmann : Last changes of Martin Mares undone. + * Gero Kuhlmann : RARP replies are tested for specified server + * again. However, it's now possible to have + * different RARP and NFS servers. + * Gero Kuhlmann : "0.0.0.0" addresses from command line are + * now mapped to INADDR_NONE. + * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name + * from being used (thanks to Leo Spiekman) + * Andy Walker : Allow to specify the NFS server in nfs_root + * without giving a path name + * Swen Thmmler : Allow to specify the NFS options in nfs_root + * without giving a path name. Fix BOOTP request + * for domainname (domainname is NIS domain, not + * DNS domain!). Skip dummy devices for BOOTP. + * Jacek Zapala : Fixed a bug which prevented server-ip address + * from nfsroot parameter from being used. + * Olaf Kirch : Adapted to new NFS code. + * Jakub Jelinek : Free used code segment. + * Marko Kohtala : Fixed some bugs. + * Martin Mares : Debug message cleanup + * Martin Mares : Changed to use the new generic IP layer autoconfig + * code. BOOTP and RARP moved there. + * Martin Mares : Default path now contains host name instead of + * host IP address (but host name defaults to IP + * address anyway). + * Martin Mares : Use root_server_addr appropriately during setup. + * Martin Mares : Rewrote parameter parsing, now hopefully giving + * correct overriding. + * Trond Myklebust : Add in preliminary support for NFSv3 and TCP. + * Fix bug in root_nfs_addr(). nfs_data.namlen + * is NOT for the length of the hostname. + * Hua Qin : Support for mounting root file system via + * NFS over TCP. + * Fabian Frederick: Option parser rebuilt (using parser lib) +*/ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/sunrpc/clnt.h> +#include <linux/nfs.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_mount.h> +#include <linux/in.h> +#include <linux/major.h> +#include <linux/utsname.h> +#include <linux/inet.h> +#include <linux/root_dev.h> +#include <net/ipconfig.h> +#include <linux/parser.h> + +/* Define this to allow debugging output */ +#undef NFSROOT_DEBUG +#define NFSDBG_FACILITY NFSDBG_ROOT + +/* Default path we try to mount. "%s" gets replaced by our IP address */ +#define NFS_ROOT "/tftpboot/%s" + +/* Parameters passed from the kernel command line */ +static char nfs_root_name[256] __initdata = ""; + +/* Address of NFS server */ +static __u32 servaddr __initdata = 0; + +/* Name of directory to mount */ +static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, }; + +/* NFS-related data */ +static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ +static int nfs_port __initdata = 0; /* Port to connect to for NFS */ +static int mount_port __initdata = 0; /* Mount daemon port number */ + + +/*************************************************************************** + + Parsing of options + + ***************************************************************************/ + +enum { + /* Options that take integer arguments */ + Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, + Opt_acregmax, Opt_acdirmin, Opt_acdirmax, + /* Options that take no arguments */ + Opt_soft, Opt_hard, Opt_intr, + Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, + Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, + /* Error token */ + Opt_err +}; + +static match_table_t __initdata tokens = { + {Opt_port, "port=%u"}, + {Opt_rsize, "rsize=%u"}, + {Opt_wsize, "wsize=%u"}, + {Opt_timeo, "timeo=%u"}, + {Opt_retrans, "retrans=%u"}, + {Opt_acregmin, "acregmin=%u"}, + {Opt_acregmax, "acregmax=%u"}, + {Opt_acdirmin, "acdirmin=%u"}, + {Opt_acdirmax, "acdirmax=%u"}, + {Opt_soft, "soft"}, + {Opt_hard, "hard"}, + {Opt_intr, "intr"}, + {Opt_nointr, "nointr"}, + {Opt_posix, "posix"}, + {Opt_noposix, "noposix"}, + {Opt_cto, "cto"}, + {Opt_nocto, "nocto"}, + {Opt_ac, "ac"}, + {Opt_noac, "noac"}, + {Opt_lock, "lock"}, + {Opt_nolock, "nolock"}, + {Opt_v2, "nfsvers=2"}, + {Opt_v2, "v2"}, + {Opt_v3, "nfsvers=3"}, + {Opt_v3, "v3"}, + {Opt_udp, "proto=udp"}, + {Opt_udp, "udp"}, + {Opt_tcp, "proto=tcp"}, + {Opt_tcp, "tcp"}, + {Opt_err, NULL} + +}; + +/* + * Parse option string. + */ + +static int __init root_nfs_parse(char *name, char *buf) +{ + + char *p; + substring_t args[MAX_OPT_ARGS]; + int option; + + if (!name) + return 1; + + /* Set the NFS remote path */ + p = strsep(&name, ","); + if (p[0] != '\0' && strcmp(p, "default") != 0) + strlcpy(buf, p, NFS_MAXPATHLEN); + + while ((p = strsep (&name, ",")) != NULL) { + int token; + if (!*p) + continue; + token = match_token(p, tokens, args); + + /* %u tokens only. Beware if you add new tokens! */ + if (token < Opt_soft && match_int(&args[0], &option)) + return 0; + switch (token) { + case Opt_port: + nfs_port = option; + break; + case Opt_rsize: + nfs_data.rsize = option; + break; + case Opt_wsize: + nfs_data.wsize = option; + break; + case Opt_timeo: + nfs_data.timeo = option; + break; + case Opt_retrans: + nfs_data.retrans = option; + break; + case Opt_acregmin: + nfs_data.acregmin = option; + break; + case Opt_acregmax: + nfs_data.acregmax = option; + break; + case Opt_acdirmin: + nfs_data.acdirmin = option; + break; + case Opt_acdirmax: + nfs_data.acdirmax = option; + break; + case Opt_soft: + nfs_data.flags |= NFS_MOUNT_SOFT; + break; + case Opt_hard: + nfs_data.flags &= ~NFS_MOUNT_SOFT; + break; + case Opt_intr: + nfs_data.flags |= NFS_MOUNT_INTR; + break; + case Opt_nointr: + nfs_data.flags &= ~NFS_MOUNT_INTR; + break; + case Opt_posix: + nfs_data.flags |= NFS_MOUNT_POSIX; + break; + case Opt_noposix: + nfs_data.flags &= ~NFS_MOUNT_POSIX; + break; + case Opt_cto: + nfs_data.flags &= ~NFS_MOUNT_NOCTO; + break; + case Opt_nocto: + nfs_data.flags |= NFS_MOUNT_NOCTO; + break; + case Opt_ac: + nfs_data.flags &= ~NFS_MOUNT_NOAC; + break; + case Opt_noac: + nfs_data.flags |= NFS_MOUNT_NOAC; + break; + case Opt_lock: + nfs_data.flags &= ~NFS_MOUNT_NONLM; + break; + case Opt_nolock: + nfs_data.flags |= NFS_MOUNT_NONLM; + break; + case Opt_v2: + nfs_data.flags &= ~NFS_MOUNT_VER3; + break; + case Opt_v3: + nfs_data.flags |= NFS_MOUNT_VER3; + break; + case Opt_udp: + nfs_data.flags &= ~NFS_MOUNT_TCP; + break; + case Opt_tcp: + nfs_data.flags |= NFS_MOUNT_TCP; + break; + default : + return 0; + } + } + + return 1; +} + +/* + * Prepare the NFS data structure and parse all options. + */ +static int __init root_nfs_name(char *name) +{ + static char buf[NFS_MAXPATHLEN] __initdata; + char *cp; + + /* Set some default values */ + memset(&nfs_data, 0, sizeof(nfs_data)); + nfs_port = -1; + nfs_data.version = NFS_MOUNT_VERSION; + nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ + nfs_data.rsize = NFS_DEF_FILE_IO_BUFFER_SIZE; + nfs_data.wsize = NFS_DEF_FILE_IO_BUFFER_SIZE; + nfs_data.acregmin = 3; + nfs_data.acregmax = 60; + nfs_data.acdirmin = 30; + nfs_data.acdirmax = 60; + strcpy(buf, NFS_ROOT); + + /* Process options received from the remote server */ + root_nfs_parse(root_server_path, buf); + + /* Override them by options set on kernel command-line */ + root_nfs_parse(name, buf); + + cp = system_utsname.nodename; + if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { + printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); + return -1; + } + sprintf(nfs_path, buf, cp); + + return 1; +} + + +/* + * Get NFS server address. + */ +static int __init root_nfs_addr(void) +{ + if ((servaddr = root_server_addr) == INADDR_NONE) { + printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); + return -1; + } + + snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), + "%u.%u.%u.%u", NIPQUAD(servaddr)); + return 0; +} + +/* + * Tell the user what's going on. + */ +#ifdef NFSROOT_DEBUG +static void __init root_nfs_print(void) +{ + printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", + nfs_path, nfs_data.hostname); + printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", + nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); + printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", + nfs_data.acregmin, nfs_data.acregmax, + nfs_data.acdirmin, nfs_data.acdirmax); + printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", + nfs_port, mount_port, nfs_data.flags); +} +#endif + + +static int __init root_nfs_init(void) +{ +#ifdef NFSROOT_DEBUG + nfs_debug |= NFSDBG_ROOT; +#endif + + /* + * Decode the root directory path name and NFS options from + * the kernel command line. This has to go here in order to + * be able to use the client IP address for the remote root + * directory (necessary for pure RARP booting). + */ + if (root_nfs_name(nfs_root_name) < 0 || + root_nfs_addr() < 0) + return -1; + +#ifdef NFSROOT_DEBUG + root_nfs_print(); +#endif + + return 0; +} + + +/* + * Parse NFS server and directory information passed on the kernel + * command line. + */ +static int __init nfs_root_setup(char *line) +{ + ROOT_DEV = Root_NFS; + if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { + strlcpy(nfs_root_name, line, sizeof(nfs_root_name)); + } else { + int n = strlen(line) + sizeof(NFS_ROOT) - 1; + if (n >= sizeof(nfs_root_name)) + line[sizeof(nfs_root_name) - sizeof(NFS_ROOT) - 2] = '\0'; + sprintf(nfs_root_name, NFS_ROOT, line); + } + root_server_addr = root_nfs_parse_addr(nfs_root_name); + return 1; +} + +__setup("nfsroot=", nfs_root_setup); + +/*************************************************************************** + + Routines to actually mount the root directory + + ***************************************************************************/ + +/* + * Construct sockaddr_in from address and port number. + */ +static inline void +set_sockaddr(struct sockaddr_in *sin, __u32 addr, __u16 port) +{ + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = addr; + sin->sin_port = port; +} + +/* + * Query server portmapper for the port of a daemon program. + */ +static int __init root_nfs_getport(int program, int version, int proto) +{ + struct sockaddr_in sin; + + printk(KERN_NOTICE "Looking up port of RPC %d/%d on %u.%u.%u.%u\n", + program, version, NIPQUAD(servaddr)); + set_sockaddr(&sin, servaddr, 0); + return rpc_getport_external(&sin, program, version, proto); +} + + +/* + * Use portmapper to find mountd and nfsd port numbers if not overriden + * by the user. Use defaults if portmapper is not available. + * XXX: Is there any nfs server with no portmapper? + */ +static int __init root_nfs_ports(void) +{ + int port; + int nfsd_ver, mountd_ver; + int nfsd_port, mountd_port; + int proto; + + if (nfs_data.flags & NFS_MOUNT_VER3) { + nfsd_ver = NFS3_VERSION; + mountd_ver = NFS_MNT3_VERSION; + nfsd_port = NFS_PORT; + mountd_port = NFS_MNT_PORT; + } else { + nfsd_ver = NFS2_VERSION; + mountd_ver = NFS_MNT_VERSION; + nfsd_port = NFS_PORT; + mountd_port = NFS_MNT_PORT; + } + + proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; + + if (nfs_port < 0) { + if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { + printk(KERN_ERR "Root-NFS: Unable to get nfsd port " + "number from server, using default\n"); + port = nfsd_port; + } + nfs_port = htons(port); + dprintk("Root-NFS: Portmapper on server returned %d " + "as nfsd port\n", port); + } + + if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { + printk(KERN_ERR "Root-NFS: Unable to get mountd port " + "number from server, using default\n"); + port = mountd_port; + } + mount_port = htons(port); + dprintk("Root-NFS: mountd port is %d\n", port); + + return 0; +} + + +/* + * Get a file handle from the server for the directory which is to be + * mounted. + */ +static int __init root_nfs_get_handle(void) +{ + struct nfs_fh fh; + struct sockaddr_in sin; + int status; + int protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? + IPPROTO_TCP : IPPROTO_UDP; + int version = (nfs_data.flags & NFS_MOUNT_VER3) ? + NFS_MNT3_VERSION : NFS_MNT_VERSION; + + set_sockaddr(&sin, servaddr, mount_port); + status = nfsroot_mount(&sin, nfs_path, &fh, version, protocol); + if (status < 0) + printk(KERN_ERR "Root-NFS: Server returned error %d " + "while mounting %s\n", status, nfs_path); + else { + nfs_data.root.size = fh.size; + memcpy(nfs_data.root.data, fh.data, fh.size); + } + + return status; +} + +/* + * 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) +{ + if (root_nfs_init() < 0 + || root_nfs_ports() < 0 + || root_nfs_get_handle() < 0) + return NULL; + set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, nfs_port); + return (void*)&nfs_data; +} |