Commit | Line | Data |
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129d1977 BS |
1 | /* |
2 | * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com> | |
3 | */ | |
4 | #include <linux/init.h> | |
fbdefd64 | 5 | #include <linux/module.h> |
129d1977 | 6 | #include <linux/nfs_idmap.h> |
fbdefd64 | 7 | #include <linux/nfs4_mount.h> |
466bfe7f | 8 | #include <linux/nfs_fs.h> |
fbdefd64 | 9 | #include "internal.h" |
466bfe7f | 10 | #include "nfs4_fs.h" |
ab7017a3 | 11 | #include "nfs.h" |
129d1977 | 12 | |
fbdefd64 BS |
13 | #define NFSDBG_FACILITY NFSDBG_VFS |
14 | ||
15 | static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type, | |
16 | int flags, const char *dev_name, void *raw_data); | |
17 | static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type, | |
18 | int flags, const char *dev_name, void *raw_data); | |
19 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, | |
20 | int flags, const char *dev_name, void *raw_data); | |
21 | static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type, | |
22 | int flags, const char *dev_name, void *raw_data); | |
23 | ||
24 | static struct file_system_type nfs4_fs_type = { | |
25 | .owner = THIS_MODULE, | |
26 | .name = "nfs4", | |
27 | .mount = nfs_fs_mount, | |
28 | .kill_sb = nfs_kill_super, | |
29 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, | |
30 | }; | |
31 | ||
32 | static struct file_system_type nfs4_remote_fs_type = { | |
33 | .owner = THIS_MODULE, | |
34 | .name = "nfs4", | |
35 | .mount = nfs4_remote_mount, | |
36 | .kill_sb = nfs_kill_super, | |
37 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, | |
38 | }; | |
39 | ||
40 | struct file_system_type nfs4_xdev_fs_type = { | |
41 | .owner = THIS_MODULE, | |
42 | .name = "nfs4", | |
43 | .mount = nfs4_xdev_mount, | |
44 | .kill_sb = nfs_kill_super, | |
45 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, | |
46 | }; | |
47 | ||
48 | static struct file_system_type nfs4_remote_referral_fs_type = { | |
49 | .owner = THIS_MODULE, | |
50 | .name = "nfs4", | |
51 | .mount = nfs4_remote_referral_mount, | |
52 | .kill_sb = nfs_kill_super, | |
53 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, | |
54 | }; | |
55 | ||
56 | struct file_system_type nfs4_referral_fs_type = { | |
57 | .owner = THIS_MODULE, | |
58 | .name = "nfs4", | |
59 | .mount = nfs4_referral_mount, | |
60 | .kill_sb = nfs_kill_super, | |
61 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, | |
62 | }; | |
63 | ||
64 | static const struct super_operations nfs4_sops = { | |
65 | .alloc_inode = nfs_alloc_inode, | |
66 | .destroy_inode = nfs_destroy_inode, | |
67 | .write_inode = nfs4_write_inode, | |
68 | .put_super = nfs_put_super, | |
69 | .statfs = nfs_statfs, | |
70 | .evict_inode = nfs4_evict_inode, | |
71 | .umount_begin = nfs_umount_begin, | |
72 | .show_options = nfs_show_options, | |
73 | .show_devname = nfs_show_devname, | |
74 | .show_path = nfs_show_path, | |
75 | .show_stats = nfs_show_stats, | |
76 | .remount_fs = nfs_remount, | |
77 | }; | |
78 | ||
ab7017a3 BS |
79 | struct nfs_subversion nfs_v4 = { |
80 | .owner = THIS_MODULE, | |
81 | .nfs_fs = &nfs4_fs_type, | |
82 | .rpc_vers = &nfs_version4, | |
83 | .rpc_ops = &nfs_v4_clientops, | |
84 | }; | |
85 | ||
fbdefd64 BS |
86 | /* |
87 | * Set up an NFS4 superblock | |
88 | */ | |
89 | static void nfs4_fill_super(struct super_block *sb, | |
90 | struct nfs_mount_info *mount_info) | |
91 | { | |
92 | sb->s_time_gran = 1; | |
93 | sb->s_op = &nfs4_sops; | |
94 | /* | |
95 | * The VFS shouldn't apply the umask to mode bits. We will do | |
96 | * so ourselves when necessary. | |
97 | */ | |
98 | sb->s_flags |= MS_POSIXACL; | |
99 | sb->s_xattr = nfs4_xattr_handlers; | |
100 | nfs_initialise_sb(sb); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Get the superblock for the NFS4 root partition | |
105 | */ | |
106 | static struct dentry * | |
107 | nfs4_remote_mount(struct file_system_type *fs_type, int flags, | |
108 | const char *dev_name, void *info) | |
109 | { | |
110 | struct nfs_mount_info *mount_info = info; | |
111 | struct nfs_server *server; | |
112 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
113 | ||
114 | mount_info->fill_super = nfs4_fill_super; | |
115 | mount_info->set_security = nfs_set_sb_security; | |
116 | ||
117 | /* Get a volume representation */ | |
118 | server = nfs4_create_server(mount_info->parsed, mount_info->mntfh); | |
119 | if (IS_ERR(server)) { | |
120 | mntroot = ERR_CAST(server); | |
121 | goto out; | |
122 | } | |
123 | ||
ab7017a3 | 124 | mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4); |
fbdefd64 BS |
125 | |
126 | out: | |
127 | return mntroot; | |
128 | } | |
129 | ||
130 | static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type, | |
131 | int flags, void *data, const char *hostname) | |
132 | { | |
133 | struct vfsmount *root_mnt; | |
134 | char *root_devname; | |
135 | size_t len; | |
136 | ||
137 | len = strlen(hostname) + 5; | |
138 | root_devname = kmalloc(len, GFP_KERNEL); | |
139 | if (root_devname == NULL) | |
140 | return ERR_PTR(-ENOMEM); | |
141 | /* Does hostname needs to be enclosed in brackets? */ | |
142 | if (strchr(hostname, ':')) | |
143 | snprintf(root_devname, len, "[%s]:/", hostname); | |
144 | else | |
145 | snprintf(root_devname, len, "%s:/", hostname); | |
146 | root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data); | |
147 | kfree(root_devname); | |
148 | return root_mnt; | |
149 | } | |
150 | ||
151 | struct nfs_referral_count { | |
152 | struct list_head list; | |
153 | const struct task_struct *task; | |
154 | unsigned int referral_count; | |
155 | }; | |
156 | ||
157 | static LIST_HEAD(nfs_referral_count_list); | |
158 | static DEFINE_SPINLOCK(nfs_referral_count_list_lock); | |
159 | ||
160 | static struct nfs_referral_count *nfs_find_referral_count(void) | |
161 | { | |
162 | struct nfs_referral_count *p; | |
163 | ||
164 | list_for_each_entry(p, &nfs_referral_count_list, list) { | |
165 | if (p->task == current) | |
166 | return p; | |
167 | } | |
168 | return NULL; | |
169 | } | |
170 | ||
171 | #define NFS_MAX_NESTED_REFERRALS 2 | |
172 | ||
173 | static int nfs_referral_loop_protect(void) | |
174 | { | |
175 | struct nfs_referral_count *p, *new; | |
176 | int ret = -ENOMEM; | |
177 | ||
178 | new = kmalloc(sizeof(*new), GFP_KERNEL); | |
179 | if (!new) | |
180 | goto out; | |
181 | new->task = current; | |
182 | new->referral_count = 1; | |
183 | ||
184 | ret = 0; | |
185 | spin_lock(&nfs_referral_count_list_lock); | |
186 | p = nfs_find_referral_count(); | |
187 | if (p != NULL) { | |
188 | if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) | |
189 | ret = -ELOOP; | |
190 | else | |
191 | p->referral_count++; | |
192 | } else { | |
193 | list_add(&new->list, &nfs_referral_count_list); | |
194 | new = NULL; | |
195 | } | |
196 | spin_unlock(&nfs_referral_count_list_lock); | |
197 | kfree(new); | |
198 | out: | |
199 | return ret; | |
200 | } | |
201 | ||
202 | static void nfs_referral_loop_unprotect(void) | |
203 | { | |
204 | struct nfs_referral_count *p; | |
205 | ||
206 | spin_lock(&nfs_referral_count_list_lock); | |
207 | p = nfs_find_referral_count(); | |
208 | p->referral_count--; | |
209 | if (p->referral_count == 0) | |
210 | list_del(&p->list); | |
211 | else | |
212 | p = NULL; | |
213 | spin_unlock(&nfs_referral_count_list_lock); | |
214 | kfree(p); | |
215 | } | |
216 | ||
217 | static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt, | |
218 | const char *export_path) | |
219 | { | |
220 | struct dentry *dentry; | |
221 | int err; | |
222 | ||
223 | if (IS_ERR(root_mnt)) | |
224 | return ERR_CAST(root_mnt); | |
225 | ||
226 | err = nfs_referral_loop_protect(); | |
227 | if (err) { | |
228 | mntput(root_mnt); | |
229 | return ERR_PTR(err); | |
230 | } | |
231 | ||
232 | dentry = mount_subtree(root_mnt, export_path); | |
233 | nfs_referral_loop_unprotect(); | |
234 | ||
235 | return dentry; | |
236 | } | |
237 | ||
238 | struct dentry *nfs4_try_mount(int flags, const char *dev_name, | |
239 | struct nfs_mount_info *mount_info) | |
240 | { | |
241 | char *export_path; | |
242 | struct vfsmount *root_mnt; | |
243 | struct dentry *res; | |
244 | struct nfs_parsed_mount_data *data = mount_info->parsed; | |
245 | ||
246 | dfprintk(MOUNT, "--> nfs4_try_mount()\n"); | |
247 | ||
248 | mount_info->fill_super = nfs4_fill_super; | |
249 | ||
250 | export_path = data->nfs_server.export_path; | |
251 | data->nfs_server.export_path = "/"; | |
252 | root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info, | |
253 | data->nfs_server.hostname); | |
254 | data->nfs_server.export_path = export_path; | |
255 | ||
256 | res = nfs_follow_remote_path(root_mnt, export_path); | |
257 | ||
258 | dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n", | |
259 | IS_ERR(res) ? PTR_ERR(res) : 0, | |
260 | IS_ERR(res) ? " [error]" : ""); | |
261 | return res; | |
262 | } | |
263 | ||
264 | /* | |
265 | * Clone an NFS4 server record on xdev traversal (FSID-change) | |
266 | */ | |
267 | static struct dentry * | |
268 | nfs4_xdev_mount(struct file_system_type *fs_type, int flags, | |
269 | const char *dev_name, void *raw_data) | |
270 | { | |
271 | struct nfs_mount_info mount_info = { | |
272 | .fill_super = nfs_clone_super, | |
273 | .set_security = nfs_clone_sb_security, | |
274 | .cloned = raw_data, | |
275 | }; | |
276 | return nfs_xdev_mount_common(&nfs4_fs_type, flags, dev_name, &mount_info); | |
277 | } | |
278 | ||
279 | static struct dentry * | |
280 | nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags, | |
281 | const char *dev_name, void *raw_data) | |
282 | { | |
283 | struct nfs_mount_info mount_info = { | |
284 | .fill_super = nfs4_fill_super, | |
285 | .set_security = nfs_clone_sb_security, | |
286 | .cloned = raw_data, | |
287 | }; | |
288 | struct nfs_server *server; | |
289 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
290 | ||
291 | dprintk("--> nfs4_referral_get_sb()\n"); | |
292 | ||
293 | mount_info.mntfh = nfs_alloc_fhandle(); | |
294 | if (mount_info.cloned == NULL || mount_info.mntfh == NULL) | |
295 | goto out; | |
296 | ||
297 | /* create a new volume representation */ | |
298 | server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh); | |
299 | if (IS_ERR(server)) { | |
300 | mntroot = ERR_CAST(server); | |
301 | goto out; | |
302 | } | |
303 | ||
ab7017a3 | 304 | mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4); |
fbdefd64 BS |
305 | out: |
306 | nfs_free_fhandle(mount_info.mntfh); | |
307 | return mntroot; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Create an NFS4 server record on referral traversal | |
312 | */ | |
313 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, | |
314 | int flags, const char *dev_name, void *raw_data) | |
315 | { | |
316 | struct nfs_clone_mount *data = raw_data; | |
317 | char *export_path; | |
318 | struct vfsmount *root_mnt; | |
319 | struct dentry *res; | |
320 | ||
321 | dprintk("--> nfs4_referral_mount()\n"); | |
322 | ||
323 | export_path = data->mnt_path; | |
324 | data->mnt_path = "/"; | |
325 | ||
326 | root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type, | |
327 | flags, data, data->hostname); | |
328 | data->mnt_path = export_path; | |
329 | ||
330 | res = nfs_follow_remote_path(root_mnt, export_path); | |
331 | dprintk("<-- nfs4_referral_mount() = %ld%s\n", | |
332 | IS_ERR(res) ? PTR_ERR(res) : 0, | |
333 | IS_ERR(res) ? " [error]" : ""); | |
334 | return res; | |
335 | } | |
336 | ||
337 | ||
129d1977 BS |
338 | int __init init_nfs_v4(void) |
339 | { | |
340 | int err; | |
341 | ||
342 | err = nfs_idmap_init(); | |
343 | if (err) | |
344 | goto out; | |
345 | ||
466bfe7f BS |
346 | err = nfs4_register_sysctl(); |
347 | if (err) | |
348 | goto out1; | |
349 | ||
fbdefd64 BS |
350 | err = register_filesystem(&nfs4_fs_type); |
351 | if (err < 0) | |
352 | goto out2; | |
353 | ||
ab7017a3 | 354 | register_nfs_version(&nfs_v4); |
129d1977 | 355 | return 0; |
fbdefd64 BS |
356 | out2: |
357 | nfs4_unregister_sysctl(); | |
466bfe7f BS |
358 | out1: |
359 | nfs_idmap_quit(); | |
129d1977 BS |
360 | out: |
361 | return err; | |
362 | } | |
363 | ||
bb6e071f | 364 | void exit_nfs_v4(void) |
129d1977 | 365 | { |
ab7017a3 | 366 | unregister_nfs_version(&nfs_v4); |
fbdefd64 | 367 | unregister_filesystem(&nfs4_fs_type); |
466bfe7f | 368 | nfs4_unregister_sysctl(); |
129d1977 BS |
369 | nfs_idmap_quit(); |
370 | } |