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> |
19d87ca3 | 9 | #include "delegation.h" |
fbdefd64 | 10 | #include "internal.h" |
466bfe7f | 11 | #include "nfs4_fs.h" |
c8d74d9b | 12 | #include "dns_resolve.h" |
19d87ca3 | 13 | #include "pnfs.h" |
ab7017a3 | 14 | #include "nfs.h" |
129d1977 | 15 | |
fbdefd64 BS |
16 | #define NFSDBG_FACILITY NFSDBG_VFS |
17 | ||
19d87ca3 BS |
18 | static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc); |
19 | static void nfs4_evict_inode(struct inode *inode); | |
fbdefd64 BS |
20 | static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type, |
21 | int flags, const char *dev_name, void *raw_data); | |
fbdefd64 BS |
22 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, |
23 | int flags, const char *dev_name, void *raw_data); | |
24 | static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type, | |
25 | int flags, const char *dev_name, void *raw_data); | |
26 | ||
fbdefd64 BS |
27 | static struct file_system_type nfs4_remote_fs_type = { |
28 | .owner = THIS_MODULE, | |
29 | .name = "nfs4", | |
30 | .mount = nfs4_remote_mount, | |
31 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 32 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
33 | }; |
34 | ||
fbdefd64 BS |
35 | static struct file_system_type nfs4_remote_referral_fs_type = { |
36 | .owner = THIS_MODULE, | |
37 | .name = "nfs4", | |
38 | .mount = nfs4_remote_referral_mount, | |
39 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 40 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
41 | }; |
42 | ||
43 | struct file_system_type nfs4_referral_fs_type = { | |
44 | .owner = THIS_MODULE, | |
45 | .name = "nfs4", | |
46 | .mount = nfs4_referral_mount, | |
47 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 48 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
49 | }; |
50 | ||
51 | static const struct super_operations nfs4_sops = { | |
52 | .alloc_inode = nfs_alloc_inode, | |
53 | .destroy_inode = nfs_destroy_inode, | |
54 | .write_inode = nfs4_write_inode, | |
eed99357 | 55 | .drop_inode = nfs_drop_inode, |
fbdefd64 BS |
56 | .statfs = nfs_statfs, |
57 | .evict_inode = nfs4_evict_inode, | |
58 | .umount_begin = nfs_umount_begin, | |
59 | .show_options = nfs_show_options, | |
60 | .show_devname = nfs_show_devname, | |
61 | .show_path = nfs_show_path, | |
62 | .show_stats = nfs_show_stats, | |
63 | .remount_fs = nfs_remount, | |
64 | }; | |
65 | ||
ab7017a3 BS |
66 | struct nfs_subversion nfs_v4 = { |
67 | .owner = THIS_MODULE, | |
68 | .nfs_fs = &nfs4_fs_type, | |
69 | .rpc_vers = &nfs_version4, | |
70 | .rpc_ops = &nfs_v4_clientops, | |
6a74490d BS |
71 | .sops = &nfs4_sops, |
72 | .xattr = nfs4_xattr_handlers, | |
ab7017a3 BS |
73 | }; |
74 | ||
19d87ca3 BS |
75 | static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc) |
76 | { | |
77 | int ret = nfs_write_inode(inode, wbc); | |
78 | ||
71244d9b TM |
79 | if (ret == 0) |
80 | ret = pnfs_layoutcommit_inode(inode, | |
81 | wbc->sync_mode == WB_SYNC_ALL); | |
19d87ca3 BS |
82 | return ret; |
83 | } | |
84 | ||
85 | /* | |
86 | * Clean out any remaining NFSv4 state that might be left over due | |
87 | * to open() calls that passed nfs_atomic_lookup, but failed to call | |
88 | * nfs_open(). | |
89 | */ | |
90 | static void nfs4_evict_inode(struct inode *inode) | |
91 | { | |
91b0abe3 | 92 | truncate_inode_pages_final(&inode->i_data); |
19d87ca3 BS |
93 | clear_inode(inode); |
94 | pnfs_return_layout(inode); | |
95 | pnfs_destroy_layout(NFS_I(inode)); | |
96 | /* If we are holding a delegation, return it! */ | |
97 | nfs_inode_return_delegation_noreclaim(inode); | |
98 | /* First call standard NFS clear_inode() code */ | |
99 | nfs_clear_inode(inode); | |
100 | } | |
101 | ||
fbdefd64 BS |
102 | /* |
103 | * Get the superblock for the NFS4 root partition | |
104 | */ | |
105 | static struct dentry * | |
106 | nfs4_remote_mount(struct file_system_type *fs_type, int flags, | |
107 | const char *dev_name, void *info) | |
108 | { | |
109 | struct nfs_mount_info *mount_info = info; | |
110 | struct nfs_server *server; | |
111 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
112 | ||
fbdefd64 BS |
113 | mount_info->set_security = nfs_set_sb_security; |
114 | ||
115 | /* Get a volume representation */ | |
1179acc6 | 116 | server = nfs4_create_server(mount_info, &nfs_v4); |
fbdefd64 BS |
117 | if (IS_ERR(server)) { |
118 | mntroot = ERR_CAST(server); | |
119 | goto out; | |
120 | } | |
121 | ||
ab7017a3 | 122 | mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4); |
fbdefd64 BS |
123 | |
124 | out: | |
125 | return mntroot; | |
126 | } | |
127 | ||
128 | static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type, | |
129 | int flags, void *data, const char *hostname) | |
130 | { | |
131 | struct vfsmount *root_mnt; | |
132 | char *root_devname; | |
133 | size_t len; | |
134 | ||
135 | len = strlen(hostname) + 5; | |
136 | root_devname = kmalloc(len, GFP_KERNEL); | |
137 | if (root_devname == NULL) | |
138 | return ERR_PTR(-ENOMEM); | |
139 | /* Does hostname needs to be enclosed in brackets? */ | |
140 | if (strchr(hostname, ':')) | |
141 | snprintf(root_devname, len, "[%s]:/", hostname); | |
142 | else | |
143 | snprintf(root_devname, len, "%s:/", hostname); | |
144 | root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data); | |
145 | kfree(root_devname); | |
146 | return root_mnt; | |
147 | } | |
148 | ||
149 | struct nfs_referral_count { | |
150 | struct list_head list; | |
151 | const struct task_struct *task; | |
152 | unsigned int referral_count; | |
153 | }; | |
154 | ||
155 | static LIST_HEAD(nfs_referral_count_list); | |
156 | static DEFINE_SPINLOCK(nfs_referral_count_list_lock); | |
157 | ||
158 | static struct nfs_referral_count *nfs_find_referral_count(void) | |
159 | { | |
160 | struct nfs_referral_count *p; | |
161 | ||
162 | list_for_each_entry(p, &nfs_referral_count_list, list) { | |
163 | if (p->task == current) | |
164 | return p; | |
165 | } | |
166 | return NULL; | |
167 | } | |
168 | ||
169 | #define NFS_MAX_NESTED_REFERRALS 2 | |
170 | ||
171 | static int nfs_referral_loop_protect(void) | |
172 | { | |
173 | struct nfs_referral_count *p, *new; | |
174 | int ret = -ENOMEM; | |
175 | ||
176 | new = kmalloc(sizeof(*new), GFP_KERNEL); | |
177 | if (!new) | |
178 | goto out; | |
179 | new->task = current; | |
180 | new->referral_count = 1; | |
181 | ||
182 | ret = 0; | |
183 | spin_lock(&nfs_referral_count_list_lock); | |
184 | p = nfs_find_referral_count(); | |
185 | if (p != NULL) { | |
186 | if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) | |
187 | ret = -ELOOP; | |
188 | else | |
189 | p->referral_count++; | |
190 | } else { | |
191 | list_add(&new->list, &nfs_referral_count_list); | |
192 | new = NULL; | |
193 | } | |
194 | spin_unlock(&nfs_referral_count_list_lock); | |
195 | kfree(new); | |
196 | out: | |
197 | return ret; | |
198 | } | |
199 | ||
200 | static void nfs_referral_loop_unprotect(void) | |
201 | { | |
202 | struct nfs_referral_count *p; | |
203 | ||
204 | spin_lock(&nfs_referral_count_list_lock); | |
205 | p = nfs_find_referral_count(); | |
206 | p->referral_count--; | |
207 | if (p->referral_count == 0) | |
208 | list_del(&p->list); | |
209 | else | |
210 | p = NULL; | |
211 | spin_unlock(&nfs_referral_count_list_lock); | |
212 | kfree(p); | |
213 | } | |
214 | ||
215 | static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt, | |
216 | const char *export_path) | |
217 | { | |
218 | struct dentry *dentry; | |
219 | int err; | |
220 | ||
221 | if (IS_ERR(root_mnt)) | |
222 | return ERR_CAST(root_mnt); | |
223 | ||
224 | err = nfs_referral_loop_protect(); | |
225 | if (err) { | |
226 | mntput(root_mnt); | |
227 | return ERR_PTR(err); | |
228 | } | |
229 | ||
230 | dentry = mount_subtree(root_mnt, export_path); | |
231 | nfs_referral_loop_unprotect(); | |
232 | ||
233 | return dentry; | |
234 | } | |
235 | ||
236 | struct dentry *nfs4_try_mount(int flags, const char *dev_name, | |
ff9099f2 BS |
237 | struct nfs_mount_info *mount_info, |
238 | struct nfs_subversion *nfs_mod) | |
fbdefd64 BS |
239 | { |
240 | char *export_path; | |
241 | struct vfsmount *root_mnt; | |
242 | struct dentry *res; | |
243 | struct nfs_parsed_mount_data *data = mount_info->parsed; | |
244 | ||
245 | dfprintk(MOUNT, "--> nfs4_try_mount()\n"); | |
246 | ||
fbdefd64 BS |
247 | export_path = data->nfs_server.export_path; |
248 | data->nfs_server.export_path = "/"; | |
249 | root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info, | |
250 | data->nfs_server.hostname); | |
251 | data->nfs_server.export_path = export_path; | |
252 | ||
253 | res = nfs_follow_remote_path(root_mnt, export_path); | |
254 | ||
6706246b GB |
255 | dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", |
256 | PTR_ERR_OR_ZERO(res), | |
257 | IS_ERR(res) ? " [error]" : ""); | |
fbdefd64 BS |
258 | return res; |
259 | } | |
260 | ||
fbdefd64 BS |
261 | static struct dentry * |
262 | nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags, | |
263 | const char *dev_name, void *raw_data) | |
264 | { | |
265 | struct nfs_mount_info mount_info = { | |
6a74490d | 266 | .fill_super = nfs_fill_super, |
fbdefd64 BS |
267 | .set_security = nfs_clone_sb_security, |
268 | .cloned = raw_data, | |
269 | }; | |
270 | struct nfs_server *server; | |
271 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
272 | ||
273 | dprintk("--> nfs4_referral_get_sb()\n"); | |
274 | ||
275 | mount_info.mntfh = nfs_alloc_fhandle(); | |
276 | if (mount_info.cloned == NULL || mount_info.mntfh == NULL) | |
277 | goto out; | |
278 | ||
279 | /* create a new volume representation */ | |
280 | server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh); | |
281 | if (IS_ERR(server)) { | |
282 | mntroot = ERR_CAST(server); | |
283 | goto out; | |
284 | } | |
285 | ||
ab7017a3 | 286 | mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4); |
fbdefd64 BS |
287 | out: |
288 | nfs_free_fhandle(mount_info.mntfh); | |
289 | return mntroot; | |
290 | } | |
291 | ||
292 | /* | |
293 | * Create an NFS4 server record on referral traversal | |
294 | */ | |
295 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, | |
296 | int flags, const char *dev_name, void *raw_data) | |
297 | { | |
298 | struct nfs_clone_mount *data = raw_data; | |
299 | char *export_path; | |
300 | struct vfsmount *root_mnt; | |
301 | struct dentry *res; | |
302 | ||
303 | dprintk("--> nfs4_referral_mount()\n"); | |
304 | ||
305 | export_path = data->mnt_path; | |
306 | data->mnt_path = "/"; | |
307 | ||
308 | root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type, | |
309 | flags, data, data->hostname); | |
310 | data->mnt_path = export_path; | |
311 | ||
312 | res = nfs_follow_remote_path(root_mnt, export_path); | |
6706246b GB |
313 | dprintk("<-- nfs4_referral_mount() = %d%s\n", |
314 | PTR_ERR_OR_ZERO(res), | |
315 | IS_ERR(res) ? " [error]" : ""); | |
fbdefd64 BS |
316 | return res; |
317 | } | |
318 | ||
319 | ||
89d77c8f | 320 | static int __init init_nfs_v4(void) |
129d1977 BS |
321 | { |
322 | int err; | |
323 | ||
c8d74d9b | 324 | err = nfs_dns_resolver_init(); |
129d1977 BS |
325 | if (err) |
326 | goto out; | |
327 | ||
c8d74d9b | 328 | err = nfs_idmap_init(); |
466bfe7f BS |
329 | if (err) |
330 | goto out1; | |
331 | ||
c8d74d9b TM |
332 | err = nfs4_register_sysctl(); |
333 | if (err) | |
334 | goto out2; | |
335 | ||
ab7017a3 | 336 | register_nfs_version(&nfs_v4); |
129d1977 | 337 | return 0; |
c8d74d9b | 338 | out2: |
466bfe7f | 339 | nfs_idmap_quit(); |
c8d74d9b TM |
340 | out1: |
341 | nfs_dns_resolver_destroy(); | |
129d1977 BS |
342 | out: |
343 | return err; | |
344 | } | |
345 | ||
89d77c8f | 346 | static void __exit exit_nfs_v4(void) |
129d1977 | 347 | { |
5f01d953 PT |
348 | /* Not called in the _init(), conditionally loaded */ |
349 | nfs4_pnfs_v3_ds_connect_unload(); | |
350 | ||
ab7017a3 | 351 | unregister_nfs_version(&nfs_v4); |
466bfe7f | 352 | nfs4_unregister_sysctl(); |
129d1977 | 353 | nfs_idmap_quit(); |
c8d74d9b | 354 | nfs_dns_resolver_destroy(); |
129d1977 | 355 | } |
89d77c8f BS |
356 | |
357 | MODULE_LICENSE("GPL"); | |
358 | ||
359 | module_init(init_nfs_v4); | |
360 | module_exit(exit_nfs_v4); |