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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 | /* | |
ef95d31e TM |
24 | * Convert the NFSv4 pathname components into a standard posix path. |
25 | * | |
26 | * Note that the resulting string will be placed at the end of the buffer | |
f7b422b1 | 27 | */ |
509de811 | 28 | static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
f7b422b1 DH |
29 | char *buffer, ssize_t buflen) |
30 | { | |
31 | char *end = buffer + buflen; | |
32 | int n; | |
33 | ||
34 | *--end = '\0'; | |
35 | buflen--; | |
36 | ||
37 | n = pathname->ncomponents; | |
38 | while (--n >= 0) { | |
509de811 | 39 | const struct nfs4_string *component = &pathname->components[n]; |
f7b422b1 DH |
40 | buflen -= component->len + 1; |
41 | if (buflen < 0) | |
42 | goto Elong; | |
43 | end -= component->len; | |
44 | memcpy(end, component->data, component->len); | |
45 | *--end = '/'; | |
46 | } | |
47 | return end; | |
48 | Elong: | |
49 | return ERR_PTR(-ENAMETOOLONG); | |
50 | } | |
51 | ||
54ceac45 DH |
52 | /* |
53 | * Determine the mount path as a string | |
54 | */ | |
55 | static char *nfs4_path(const struct vfsmount *mnt_parent, | |
56 | const struct dentry *dentry, | |
57 | char *buffer, ssize_t buflen) | |
58 | { | |
59 | const char *srvpath; | |
60 | ||
61 | srvpath = strchr(mnt_parent->mnt_devname, ':'); | |
62 | if (srvpath) | |
63 | srvpath++; | |
64 | else | |
65 | srvpath = mnt_parent->mnt_devname; | |
66 | ||
67 | return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen); | |
68 | } | |
69 | ||
70 | /* | |
71 | * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we | |
72 | * believe to be the server path to this dentry | |
73 | */ | |
74 | static int nfs4_validate_fspath(const struct vfsmount *mnt_parent, | |
75 | const struct dentry *dentry, | |
76 | const struct nfs4_fs_locations *locations, | |
77 | char *page, char *page2) | |
78 | { | |
79 | const char *path, *fs_path; | |
80 | ||
81 | path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE); | |
82 | if (IS_ERR(path)) | |
83 | return PTR_ERR(path); | |
84 | ||
85 | fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE); | |
86 | if (IS_ERR(fs_path)) | |
87 | return PTR_ERR(fs_path); | |
88 | ||
89 | if (strncmp(path, fs_path, strlen(fs_path)) != 0) { | |
90 | dprintk("%s: path %s does not begin with fsroot %s\n", | |
3110ff80 | 91 | __func__, path, fs_path); |
54ceac45 DH |
92 | return -ENOENT; |
93 | } | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
4ada29d5 BF |
98 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
99 | char *page, char *page2, | |
100 | const struct nfs4_fs_location *location) | |
101 | { | |
102 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
103 | char *mnt_path; | |
ef95d31e | 104 | unsigned int maxbuflen; |
460cdbc8 | 105 | unsigned int s; |
4ada29d5 BF |
106 | |
107 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
108 | if (IS_ERR(mnt_path)) | |
109 | return mnt; | |
110 | mountdata->mnt_path = mnt_path; | |
ef95d31e | 111 | maxbuflen = mnt_path - 1 - page2; |
4ada29d5 | 112 | |
460cdbc8 | 113 | for (s = 0; s < location->nservers; s++) { |
ea31a443 BF |
114 | const struct nfs4_string *buf = &location->servers[s]; |
115 | struct sockaddr_storage addr; | |
4ada29d5 | 116 | |
ef95d31e | 117 | if (buf->len <= 0 || buf->len >= maxbuflen) |
4ada29d5 | 118 | continue; |
4ada29d5 | 119 | |
4ada29d5 | 120 | mountdata->addr = (struct sockaddr *)&addr; |
ea31a443 BF |
121 | |
122 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) | |
123 | continue; | |
124 | nfs_parse_ip_address(buf->data, buf->len, | |
125 | mountdata->addr, &mountdata->addrlen); | |
126 | if (mountdata->addr->sa_family == AF_UNSPEC) | |
127 | continue; | |
128 | nfs_set_port(mountdata->addr, NFS_PORT); | |
129 | ||
ef95d31e TM |
130 | memcpy(page2, buf->data, buf->len); |
131 | page2[buf->len] = '\0'; | |
ea31a443 | 132 | mountdata->hostname = page2; |
4ada29d5 BF |
133 | |
134 | snprintf(page, PAGE_SIZE, "%s:%s", | |
135 | mountdata->hostname, | |
136 | mountdata->mnt_path); | |
137 | ||
138 | mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); | |
139 | if (!IS_ERR(mnt)) | |
140 | break; | |
4ada29d5 BF |
141 | } |
142 | return mnt; | |
143 | } | |
144 | ||
f7b422b1 DH |
145 | /** |
146 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
147 | * @mnt_parent - mountpoint of parent directory | |
148 | * @dentry - parent directory | |
3f43c666 | 149 | * @locations - array of NFSv4 server location information |
f7b422b1 DH |
150 | * |
151 | */ | |
152 | static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent, | |
153 | const struct dentry *dentry, | |
509de811 | 154 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
155 | { |
156 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
157 | struct nfs_clone_mount mountdata = { | |
158 | .sb = mnt_parent->mnt_sb, | |
159 | .dentry = dentry, | |
160 | .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor, | |
161 | }; | |
54ceac45 | 162 | char *page = NULL, *page2 = NULL; |
3f43c666 | 163 | int loc, error; |
f7b422b1 DH |
164 | |
165 | if (locations == NULL || locations->nlocations <= 0) | |
166 | goto out; | |
167 | ||
3110ff80 | 168 | dprintk("%s: referral at %s/%s\n", __func__, |
f7b422b1 DH |
169 | dentry->d_parent->d_name.name, dentry->d_name.name); |
170 | ||
f7b422b1 | 171 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 172 | if (!page) |
f7b422b1 | 173 | goto out; |
54ceac45 | 174 | |
f7b422b1 | 175 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 176 | if (!page2) |
f7b422b1 DH |
177 | goto out; |
178 | ||
54ceac45 DH |
179 | /* Ensure fs path is a prefix of current dentry path */ |
180 | error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2); | |
181 | if (error < 0) { | |
182 | mnt = ERR_PTR(error); | |
183 | goto out; | |
f7b422b1 DH |
184 | } |
185 | ||
460cdbc8 | 186 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 187 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
188 | |
189 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 190 | location->rootpath.ncomponents == 0) |
f7b422b1 | 191 | continue; |
f7b422b1 | 192 | |
4ada29d5 BF |
193 | mnt = try_location(&mountdata, page, page2, location); |
194 | if (!IS_ERR(mnt)) | |
195 | break; | |
f7b422b1 DH |
196 | } |
197 | ||
f7b422b1 | 198 | out: |
54ceac45 DH |
199 | free_page((unsigned long) page); |
200 | free_page((unsigned long) page2); | |
3110ff80 | 201 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
202 | return mnt; |
203 | } | |
204 | ||
205 | /* | |
206 | * nfs_do_refmount - handle crossing a referral on server | |
207 | * @dentry - dentry of referral | |
208 | * @nd - nameidata info | |
209 | * | |
210 | */ | |
211 | struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry) | |
212 | { | |
54ceac45 | 213 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
214 | struct dentry *parent; |
215 | struct nfs4_fs_locations *fs_locations = NULL; | |
216 | struct page *page; | |
217 | int err; | |
218 | ||
219 | /* BUG_ON(IS_ROOT(dentry)); */ | |
3110ff80 | 220 | dprintk("%s: enter\n", __func__); |
f7b422b1 DH |
221 | |
222 | page = alloc_page(GFP_KERNEL); | |
223 | if (page == NULL) | |
224 | goto out; | |
225 | ||
226 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
227 | if (fs_locations == NULL) | |
228 | goto out_free; | |
229 | ||
230 | /* Get locations */ | |
54ceac45 DH |
231 | mnt = ERR_PTR(-ENOENT); |
232 | ||
f7b422b1 | 233 | parent = dget_parent(dentry); |
54ceac45 | 234 | dprintk("%s: getting locations for %s/%s\n", |
3110ff80 | 235 | __func__, parent->d_name.name, dentry->d_name.name); |
54ceac45 | 236 | |
c228fd3a | 237 | err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page); |
f7b422b1 | 238 | dput(parent); |
54ceac45 DH |
239 | if (err != 0 || |
240 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
241 | fs_locations->fs_path.ncomponents <= 0) |
242 | goto out_free; | |
243 | ||
244 | mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations); | |
245 | out_free: | |
246 | __free_page(page); | |
247 | kfree(fs_locations); | |
248 | out: | |
3110ff80 | 249 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
250 | return mnt; |
251 | } |