blob: bb80c49b6533b44aab58171dcd69397ff02f39a2 [file] [log] [blame]
David Howellsf7b422b2006-06-09 09:34:33 -04001/*
2 * linux/fs/nfs/nfs4namespace.c
3 *
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
David Howells54ceac42006-08-22 20:06:13 -04005 * - Modified by David Howells <dhowells@redhat.com>
David Howellsf7b422b2006-06-09 09:34:33 -04006 *
7 * NFSv4 namespace
8 */
9
David Howellsf7b422b2006-06-09 09:34:33 -040010#include <linux/dcache.h>
11#include <linux/mount.h>
12#include <linux/namei.h>
13#include <linux/nfs_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
David Howellsf7b422b2006-06-09 09:34:33 -040015#include <linux/string.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/vfs.h>
18#include <linux/inet.h>
19#include "internal.h"
Trond Myklebustc228fd32007-01-13 02:28:11 -050020#include "nfs4_fs.h"
Trond Myklebust7d7ea882009-08-19 18:12:34 -040021#include "dns_resolve.h"
David Howellsf7b422b2006-06-09 09:34:33 -040022
23#define NFSDBG_FACILITY NFSDBG_VFS
24
25/*
Trond Myklebustef95d312009-03-10 20:33:17 -040026 * Convert the NFSv4 pathname components into a standard posix path.
27 *
28 * Note that the resulting string will be placed at the end of the buffer
David Howellsf7b422b2006-06-09 09:34:33 -040029 */
David Howells509de812006-08-22 20:06:11 -040030static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040031 char *buffer, ssize_t buflen)
32{
33 char *end = buffer + buflen;
34 int n;
35
36 *--end = '\0';
37 buflen--;
38
39 n = pathname->ncomponents;
40 while (--n >= 0) {
David Howells509de812006-08-22 20:06:11 -040041 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040042 buflen -= component->len + 1;
43 if (buflen < 0)
44 goto Elong;
45 end -= component->len;
46 memcpy(end, component->data, component->len);
47 *--end = '/';
48 }
49 return end;
50Elong:
51 return ERR_PTR(-ENAMETOOLONG);
52}
53
David Howells54ceac42006-08-22 20:06:13 -040054/*
55 * Determine the mount path as a string
56 */
Al Virob514f872011-03-16 06:26:11 -040057static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040058{
Al Virob514f872011-03-16 06:26:11 -040059 char *limit;
60 char *path = nfs_path(&limit, dentry, buffer, buflen);
61 if (!IS_ERR(path)) {
62 char *colon = strchr(path, ':');
63 if (colon && colon < limit)
64 path = colon + 1;
65 }
66 return path;
David Howells54ceac42006-08-22 20:06:13 -040067}
68
69/*
70 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
71 * believe to be the server path to this dentry
72 */
Al Virob514f872011-03-16 06:26:11 -040073static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -040074 const struct nfs4_fs_locations *locations,
75 char *page, char *page2)
76{
77 const char *path, *fs_path;
78
Al Virob514f872011-03-16 06:26:11 -040079 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -040080 if (IS_ERR(path))
81 return PTR_ERR(path);
82
83 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
84 if (IS_ERR(fs_path))
85 return PTR_ERR(fs_path);
86
87 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
88 dprintk("%s: path %s does not begin with fsroot %s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -070089 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -040090 return -ENOENT;
91 }
92
93 return 0;
94}
95
Trond Myklebust7d7ea882009-08-19 18:12:34 -040096static size_t nfs_parse_server_name(char *string, size_t len,
97 struct sockaddr *sa, size_t salen)
98{
99 ssize_t ret;
100
101 ret = rpc_pton(string, len, sa, salen);
102 if (ret == 0) {
103 ret = nfs_dns_resolve_name(string, len, sa, salen);
104 if (ret < 0)
105 ret = 0;
106 }
107 return ret;
108}
109
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400110static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
111 char *page, char *page2,
112 const struct nfs4_fs_location *location)
113{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400114 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400115 struct vfsmount *mnt = ERR_PTR(-ENOENT);
116 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400117 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400118 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400119
120 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
121 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400122 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400123 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400124 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400125
Trond Myklebust364d015e52010-04-16 16:22:46 -0400126 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
127 if (mountdata->addr == NULL)
128 return ERR_PTR(-ENOMEM);
129
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400130 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a442008-08-20 16:10:23 -0400131 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400132
Trond Myklebustef95d312009-03-10 20:33:17 -0400133 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400134 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400135
J. Bruce Fieldsea31a442008-08-20 16:10:23 -0400136 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
137 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400138
139 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Trond Myklebust364d015e52010-04-16 16:22:46 -0400140 mountdata->addr, addr_bufsize);
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400141 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a442008-08-20 16:10:23 -0400142 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400143
Chuck Leverec6ee612009-08-09 15:09:37 -0400144 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a442008-08-20 16:10:23 -0400145
Trond Myklebustef95d312009-03-10 20:33:17 -0400146 memcpy(page2, buf->data, buf->len);
147 page2[buf->len] = '\0';
J. Bruce Fieldsea31a442008-08-20 16:10:23 -0400148 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400149
150 snprintf(page, PAGE_SIZE, "%s:%s",
151 mountdata->hostname,
152 mountdata->mnt_path);
153
154 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
155 if (!IS_ERR(mnt))
156 break;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400157 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400158 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400159 return mnt;
160}
161
David Howellsf7b422b2006-06-09 09:34:33 -0400162/**
163 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400164 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500165 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400166 *
167 */
Al Virof8ad9c42011-03-16 06:32:07 -0400168static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400169 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400170{
171 struct vfsmount *mnt = ERR_PTR(-ENOENT);
172 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400173 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400174 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400175 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400176 };
David Howells54ceac42006-08-22 20:06:13 -0400177 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500178 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400179
180 if (locations == NULL || locations->nlocations <= 0)
181 goto out;
182
Harvey Harrison3110ff82008-05-02 13:42:44 -0700183 dprintk("%s: referral at %s/%s\n", __func__,
David Howellsf7b422b2006-06-09 09:34:33 -0400184 dentry->d_parent->d_name.name, dentry->d_name.name);
185
David Howellsf7b422b2006-06-09 09:34:33 -0400186 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400187 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400188 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400189
David Howellsf7b422b2006-06-09 09:34:33 -0400190 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400191 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400192 goto out;
193
David Howells54ceac42006-08-22 20:06:13 -0400194 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400195 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400196 if (error < 0) {
197 mnt = ERR_PTR(error);
198 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400199 }
200
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400201 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400202 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400203
204 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400205 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400206 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400207
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400208 mnt = try_location(&mountdata, page, page2, location);
209 if (!IS_ERR(mnt))
210 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400211 }
212
David Howellsf7b422b2006-06-09 09:34:33 -0400213out:
David Howells54ceac42006-08-22 20:06:13 -0400214 free_page((unsigned long) page);
215 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700216 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400217 return mnt;
218}
219
220/*
221 * nfs_do_refmount - handle crossing a referral on server
222 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400223 *
224 */
Al Virof8ad9c42011-03-16 06:32:07 -0400225struct vfsmount *nfs_do_refmount(struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400226{
David Howells54ceac42006-08-22 20:06:13 -0400227 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400228 struct dentry *parent;
229 struct nfs4_fs_locations *fs_locations = NULL;
230 struct page *page;
231 int err;
232
233 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700234 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400235
236 page = alloc_page(GFP_KERNEL);
237 if (page == NULL)
238 goto out;
239
240 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
241 if (fs_locations == NULL)
242 goto out_free;
243
244 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400245 mnt = ERR_PTR(-ENOENT);
246
David Howellsf7b422b2006-06-09 09:34:33 -0400247 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400248 dprintk("%s: getting locations for %s/%s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700249 __func__, parent->d_name.name, dentry->d_name.name);
David Howells54ceac42006-08-22 20:06:13 -0400250
Trond Myklebustc228fd32007-01-13 02:28:11 -0500251 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400252 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400253 if (err != 0 ||
254 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400255 fs_locations->fs_path.ncomponents <= 0)
256 goto out_free;
257
Al Virof8ad9c42011-03-16 06:32:07 -0400258 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400259out_free:
260 __free_page(page);
261 kfree(fs_locations);
262out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700263 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400264 return mnt;
265}