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