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