Commit | Line | Data |
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f7b422b1 DH |
1 | /* |
2 | * linux/fs/nfs/nfs4namespace.c | |
3 | * | |
4 | * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com> | |
54ceac45 | 5 | * - Modified by David Howells <dhowells@redhat.com> |
f7b422b1 DH |
6 | * |
7 | * NFSv4 namespace | |
8 | */ | |
9 | ||
f7b422b1 DH |
10 | #include <linux/dcache.h> |
11 | #include <linux/mount.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/nfs_fs.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/sunrpc/clnt.h> | |
16 | #include <linux/vfs.h> | |
17 | #include <linux/inet.h> | |
18 | #include "internal.h" | |
c228fd3a | 19 | #include "nfs4_fs.h" |
f7b422b1 DH |
20 | |
21 | #define NFSDBG_FACILITY NFSDBG_VFS | |
22 | ||
23 | /* | |
24 | * Check if fs_root is valid | |
25 | */ | |
509de811 | 26 | static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
f7b422b1 DH |
27 | char *buffer, ssize_t buflen) |
28 | { | |
29 | char *end = buffer + buflen; | |
30 | int n; | |
31 | ||
32 | *--end = '\0'; | |
33 | buflen--; | |
34 | ||
35 | n = pathname->ncomponents; | |
36 | while (--n >= 0) { | |
509de811 | 37 | const struct nfs4_string *component = &pathname->components[n]; |
f7b422b1 DH |
38 | buflen -= component->len + 1; |
39 | if (buflen < 0) | |
40 | goto Elong; | |
41 | end -= component->len; | |
42 | memcpy(end, component->data, component->len); | |
43 | *--end = '/'; | |
44 | } | |
45 | return end; | |
46 | Elong: | |
47 | return ERR_PTR(-ENAMETOOLONG); | |
48 | } | |
49 | ||
54ceac45 DH |
50 | /* |
51 | * Determine the mount path as a string | |
52 | */ | |
53 | static char *nfs4_path(const struct vfsmount *mnt_parent, | |
54 | const struct dentry *dentry, | |
55 | char *buffer, ssize_t buflen) | |
56 | { | |
57 | const char *srvpath; | |
58 | ||
59 | srvpath = strchr(mnt_parent->mnt_devname, ':'); | |
60 | if (srvpath) | |
61 | srvpath++; | |
62 | else | |
63 | srvpath = mnt_parent->mnt_devname; | |
64 | ||
65 | return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen); | |
66 | } | |
67 | ||
68 | /* | |
69 | * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we | |
70 | * believe to be the server path to this dentry | |
71 | */ | |
72 | static int nfs4_validate_fspath(const struct vfsmount *mnt_parent, | |
73 | const struct dentry *dentry, | |
74 | const struct nfs4_fs_locations *locations, | |
75 | char *page, char *page2) | |
76 | { | |
77 | const char *path, *fs_path; | |
78 | ||
79 | path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE); | |
80 | 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", | |
3110ff80 | 89 | __func__, path, fs_path); |
54ceac45 DH |
90 | return -ENOENT; |
91 | } | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
4ada29d5 BF |
96 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
97 | char *page, char *page2, | |
98 | const struct nfs4_fs_location *location) | |
99 | { | |
100 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
101 | char *mnt_path; | |
ea31a443 | 102 | int page2len; |
460cdbc8 | 103 | unsigned int s; |
4ada29d5 BF |
104 | |
105 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
106 | if (IS_ERR(mnt_path)) | |
107 | return mnt; | |
108 | mountdata->mnt_path = mnt_path; | |
ea31a443 BF |
109 | page2 += strlen(mnt_path) + 1; |
110 | page2len = PAGE_SIZE - strlen(mnt_path) - 1; | |
4ada29d5 | 111 | |
460cdbc8 | 112 | for (s = 0; s < location->nservers; s++) { |
ea31a443 BF |
113 | const struct nfs4_string *buf = &location->servers[s]; |
114 | struct sockaddr_storage addr; | |
4ada29d5 | 115 | |
ea31a443 | 116 | if (buf->len <= 0 || buf->len >= PAGE_SIZE) |
4ada29d5 | 117 | continue; |
4ada29d5 | 118 | |
4ada29d5 | 119 | mountdata->addr = (struct sockaddr *)&addr; |
ea31a443 BF |
120 | |
121 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) | |
122 | continue; | |
123 | nfs_parse_ip_address(buf->data, buf->len, | |
124 | mountdata->addr, &mountdata->addrlen); | |
125 | if (mountdata->addr->sa_family == AF_UNSPEC) | |
126 | continue; | |
127 | nfs_set_port(mountdata->addr, NFS_PORT); | |
128 | ||
129 | strncpy(page2, buf->data, page2len); | |
130 | page2[page2len] = '\0'; | |
131 | mountdata->hostname = page2; | |
4ada29d5 BF |
132 | |
133 | snprintf(page, PAGE_SIZE, "%s:%s", | |
134 | mountdata->hostname, | |
135 | mountdata->mnt_path); | |
136 | ||
137 | mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); | |
138 | if (!IS_ERR(mnt)) | |
139 | break; | |
4ada29d5 BF |
140 | } |
141 | return mnt; | |
142 | } | |
143 | ||
f7b422b1 DH |
144 | /** |
145 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
146 | * @mnt_parent - mountpoint of parent directory | |
147 | * @dentry - parent directory | |
3f43c666 | 148 | * @locations - array of NFSv4 server location information |
f7b422b1 DH |
149 | * |
150 | */ | |
151 | static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent, | |
152 | const struct dentry *dentry, | |
509de811 | 153 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
154 | { |
155 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
156 | struct nfs_clone_mount mountdata = { | |
157 | .sb = mnt_parent->mnt_sb, | |
158 | .dentry = dentry, | |
159 | .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor, | |
160 | }; | |
54ceac45 | 161 | char *page = NULL, *page2 = NULL; |
3f43c666 | 162 | int loc, error; |
f7b422b1 DH |
163 | |
164 | if (locations == NULL || locations->nlocations <= 0) | |
165 | goto out; | |
166 | ||
3110ff80 | 167 | dprintk("%s: referral at %s/%s\n", __func__, |
f7b422b1 DH |
168 | dentry->d_parent->d_name.name, dentry->d_name.name); |
169 | ||
f7b422b1 | 170 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 171 | if (!page) |
f7b422b1 | 172 | goto out; |
54ceac45 | 173 | |
f7b422b1 | 174 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 175 | if (!page2) |
f7b422b1 DH |
176 | goto out; |
177 | ||
54ceac45 DH |
178 | /* Ensure fs path is a prefix of current dentry path */ |
179 | error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2); | |
180 | if (error < 0) { | |
181 | mnt = ERR_PTR(error); | |
182 | goto out; | |
f7b422b1 DH |
183 | } |
184 | ||
460cdbc8 | 185 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 186 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
187 | |
188 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 189 | location->rootpath.ncomponents == 0) |
f7b422b1 | 190 | continue; |
f7b422b1 | 191 | |
4ada29d5 BF |
192 | mnt = try_location(&mountdata, page, page2, location); |
193 | if (!IS_ERR(mnt)) | |
194 | break; | |
f7b422b1 DH |
195 | } |
196 | ||
f7b422b1 | 197 | out: |
54ceac45 DH |
198 | free_page((unsigned long) page); |
199 | free_page((unsigned long) page2); | |
3110ff80 | 200 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
201 | return mnt; |
202 | } | |
203 | ||
204 | /* | |
205 | * nfs_do_refmount - handle crossing a referral on server | |
206 | * @dentry - dentry of referral | |
207 | * @nd - nameidata info | |
208 | * | |
209 | */ | |
210 | struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry) | |
211 | { | |
54ceac45 | 212 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
213 | struct dentry *parent; |
214 | struct nfs4_fs_locations *fs_locations = NULL; | |
215 | struct page *page; | |
216 | int err; | |
217 | ||
218 | /* BUG_ON(IS_ROOT(dentry)); */ | |
3110ff80 | 219 | dprintk("%s: enter\n", __func__); |
f7b422b1 DH |
220 | |
221 | page = alloc_page(GFP_KERNEL); | |
222 | if (page == NULL) | |
223 | goto out; | |
224 | ||
225 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
226 | if (fs_locations == NULL) | |
227 | goto out_free; | |
228 | ||
229 | /* Get locations */ | |
54ceac45 DH |
230 | mnt = ERR_PTR(-ENOENT); |
231 | ||
f7b422b1 | 232 | parent = dget_parent(dentry); |
54ceac45 | 233 | dprintk("%s: getting locations for %s/%s\n", |
3110ff80 | 234 | __func__, parent->d_name.name, dentry->d_name.name); |
54ceac45 | 235 | |
c228fd3a | 236 | err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page); |
f7b422b1 | 237 | dput(parent); |
54ceac45 DH |
238 | if (err != 0 || |
239 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
240 | fs_locations->fs_path.ncomponents <= 0) |
241 | goto out_free; | |
242 | ||
243 | mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations); | |
244 | out_free: | |
245 | __free_page(page); | |
246 | kfree(fs_locations); | |
247 | out: | |
3110ff80 | 248 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
249 | return mnt; |
250 | } |