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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
129d1977 BS |
2 | /* |
3 | * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com> | |
4 | */ | |
5 | #include <linux/init.h> | |
fbdefd64 | 6 | #include <linux/module.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" |
40c64c26 | 12 | #include "nfs4idmap.h" |
c8d74d9b | 13 | #include "dns_resolve.h" |
19d87ca3 | 14 | #include "pnfs.h" |
ab7017a3 | 15 | #include "nfs.h" |
129d1977 | 16 | |
fbdefd64 BS |
17 | #define NFSDBG_FACILITY NFSDBG_VFS |
18 | ||
19d87ca3 BS |
19 | static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc); |
20 | static void nfs4_evict_inode(struct inode *inode); | |
fbdefd64 BS |
21 | static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type, |
22 | int flags, const char *dev_name, void *raw_data); | |
fbdefd64 BS |
23 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, |
24 | int flags, const char *dev_name, void *raw_data); | |
25 | static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type, | |
26 | int flags, const char *dev_name, void *raw_data); | |
27 | ||
fbdefd64 BS |
28 | static struct file_system_type nfs4_remote_fs_type = { |
29 | .owner = THIS_MODULE, | |
30 | .name = "nfs4", | |
31 | .mount = nfs4_remote_mount, | |
32 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 33 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
34 | }; |
35 | ||
fbdefd64 BS |
36 | static struct file_system_type nfs4_remote_referral_fs_type = { |
37 | .owner = THIS_MODULE, | |
38 | .name = "nfs4", | |
39 | .mount = nfs4_remote_referral_mount, | |
40 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 41 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
42 | }; |
43 | ||
44 | struct file_system_type nfs4_referral_fs_type = { | |
45 | .owner = THIS_MODULE, | |
46 | .name = "nfs4", | |
47 | .mount = nfs4_referral_mount, | |
48 | .kill_sb = nfs_kill_super, | |
ecf3d1f1 | 49 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA, |
fbdefd64 BS |
50 | }; |
51 | ||
52 | static const struct super_operations nfs4_sops = { | |
53 | .alloc_inode = nfs_alloc_inode, | |
ca1a199e | 54 | .free_inode = nfs_free_inode, |
fbdefd64 | 55 | .write_inode = nfs4_write_inode, |
eed99357 | 56 | .drop_inode = nfs_drop_inode, |
fbdefd64 BS |
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 | 94 | clear_inode(inode); |
19d87ca3 BS |
95 | /* If we are holding a delegation, return it! */ |
96 | nfs_inode_return_delegation_noreclaim(inode); | |
415320fc TM |
97 | /* Note that above delegreturn would trigger pnfs return-on-close */ |
98 | pnfs_return_layout(inode); | |
99 | pnfs_destroy_layout(NFS_I(inode)); | |
19d87ca3 BS |
100 | /* First call standard NFS clear_inode() code */ |
101 | nfs_clear_inode(inode); | |
102 | } | |
103 | ||
fbdefd64 BS |
104 | /* |
105 | * Get the superblock for the NFS4 root partition | |
106 | */ | |
107 | static struct dentry * | |
108 | nfs4_remote_mount(struct file_system_type *fs_type, int flags, | |
109 | const char *dev_name, void *info) | |
110 | { | |
111 | struct nfs_mount_info *mount_info = info; | |
112 | struct nfs_server *server; | |
113 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
114 | ||
fbdefd64 BS |
115 | mount_info->set_security = nfs_set_sb_security; |
116 | ||
117 | /* Get a volume representation */ | |
1179acc6 | 118 | server = nfs4_create_server(mount_info, &nfs_v4); |
fbdefd64 BS |
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, | |
ff9099f2 BS |
239 | struct nfs_mount_info *mount_info, |
240 | struct nfs_subversion *nfs_mod) | |
fbdefd64 BS |
241 | { |
242 | char *export_path; | |
243 | struct vfsmount *root_mnt; | |
244 | struct dentry *res; | |
245 | struct nfs_parsed_mount_data *data = mount_info->parsed; | |
246 | ||
247 | dfprintk(MOUNT, "--> nfs4_try_mount()\n"); | |
248 | ||
fbdefd64 BS |
249 | export_path = data->nfs_server.export_path; |
250 | data->nfs_server.export_path = "/"; | |
251 | root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info, | |
252 | data->nfs_server.hostname); | |
253 | data->nfs_server.export_path = export_path; | |
254 | ||
255 | res = nfs_follow_remote_path(root_mnt, export_path); | |
256 | ||
6706246b GB |
257 | dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", |
258 | PTR_ERR_OR_ZERO(res), | |
259 | IS_ERR(res) ? " [error]" : ""); | |
fbdefd64 BS |
260 | return res; |
261 | } | |
262 | ||
fbdefd64 BS |
263 | static struct dentry * |
264 | nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags, | |
265 | const char *dev_name, void *raw_data) | |
266 | { | |
267 | struct nfs_mount_info mount_info = { | |
6a74490d | 268 | .fill_super = nfs_fill_super, |
fbdefd64 BS |
269 | .set_security = nfs_clone_sb_security, |
270 | .cloned = raw_data, | |
271 | }; | |
272 | struct nfs_server *server; | |
273 | struct dentry *mntroot = ERR_PTR(-ENOMEM); | |
274 | ||
275 | dprintk("--> nfs4_referral_get_sb()\n"); | |
276 | ||
277 | mount_info.mntfh = nfs_alloc_fhandle(); | |
278 | if (mount_info.cloned == NULL || mount_info.mntfh == NULL) | |
279 | goto out; | |
280 | ||
281 | /* create a new volume representation */ | |
282 | server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh); | |
283 | if (IS_ERR(server)) { | |
284 | mntroot = ERR_CAST(server); | |
285 | goto out; | |
286 | } | |
287 | ||
ab7017a3 | 288 | mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4); |
fbdefd64 BS |
289 | out: |
290 | nfs_free_fhandle(mount_info.mntfh); | |
291 | return mntroot; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Create an NFS4 server record on referral traversal | |
296 | */ | |
297 | static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, | |
298 | int flags, const char *dev_name, void *raw_data) | |
299 | { | |
300 | struct nfs_clone_mount *data = raw_data; | |
301 | char *export_path; | |
302 | struct vfsmount *root_mnt; | |
303 | struct dentry *res; | |
304 | ||
305 | dprintk("--> nfs4_referral_mount()\n"); | |
306 | ||
307 | export_path = data->mnt_path; | |
308 | data->mnt_path = "/"; | |
309 | ||
310 | root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type, | |
311 | flags, data, data->hostname); | |
312 | data->mnt_path = export_path; | |
313 | ||
314 | res = nfs_follow_remote_path(root_mnt, export_path); | |
6706246b GB |
315 | dprintk("<-- nfs4_referral_mount() = %d%s\n", |
316 | PTR_ERR_OR_ZERO(res), | |
317 | IS_ERR(res) ? " [error]" : ""); | |
fbdefd64 BS |
318 | return res; |
319 | } | |
320 | ||
321 | ||
89d77c8f | 322 | static int __init init_nfs_v4(void) |
129d1977 BS |
323 | { |
324 | int err; | |
325 | ||
c8d74d9b | 326 | err = nfs_dns_resolver_init(); |
129d1977 BS |
327 | if (err) |
328 | goto out; | |
329 | ||
c8d74d9b | 330 | err = nfs_idmap_init(); |
466bfe7f BS |
331 | if (err) |
332 | goto out1; | |
333 | ||
c8d74d9b TM |
334 | err = nfs4_register_sysctl(); |
335 | if (err) | |
336 | goto out2; | |
337 | ||
ab7017a3 | 338 | register_nfs_version(&nfs_v4); |
129d1977 | 339 | return 0; |
c8d74d9b | 340 | out2: |
466bfe7f | 341 | nfs_idmap_quit(); |
c8d74d9b TM |
342 | out1: |
343 | nfs_dns_resolver_destroy(); | |
129d1977 BS |
344 | out: |
345 | return err; | |
346 | } | |
347 | ||
89d77c8f | 348 | static void __exit exit_nfs_v4(void) |
129d1977 | 349 | { |
5f01d953 PT |
350 | /* Not called in the _init(), conditionally loaded */ |
351 | nfs4_pnfs_v3_ds_connect_unload(); | |
352 | ||
ab7017a3 | 353 | unregister_nfs_version(&nfs_v4); |
466bfe7f | 354 | nfs4_unregister_sysctl(); |
129d1977 | 355 | nfs_idmap_quit(); |
c8d74d9b | 356 | nfs_dns_resolver_destroy(); |
129d1977 | 357 | } |
89d77c8f BS |
358 | |
359 | MODULE_LICENSE("GPL"); | |
360 | ||
361 | module_init(init_nfs_v4); | |
362 | module_exit(exit_nfs_v4); |