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1/*
2 * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
3 */
4#include <linux/init.h>
5#include <linux/module.h>
6#include <linux/nfs4_mount.h>
7#include <linux/nfs_fs.h>
8#include "delegation.h"
9#include "internal.h"
10#include "nfs4_fs.h"
11#include "nfs4idmap.h"
12#include "dns_resolve.h"
13#include "pnfs.h"
14#include "nfs.h"
15
16#define NFSDBG_FACILITY NFSDBG_VFS
17
18static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
19static void nfs4_evict_inode(struct inode *inode);
20static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
21 int flags, const char *dev_name, void *raw_data);
22static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
23 int flags, const char *dev_name, void *raw_data);
24static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
25 int flags, const char *dev_name, void *raw_data);
26
27static 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,
32 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
33};
34
35static 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,
40 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
41};
42
43struct 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,
48 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
49};
50
51static const struct super_operations nfs4_sops = {
52 .alloc_inode = nfs_alloc_inode,
53 .destroy_inode = nfs_destroy_inode,
54 .write_inode = nfs4_write_inode,
55 .drop_inode = nfs_drop_inode,
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
66struct 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,
71 .sops = &nfs4_sops,
72 .xattr = nfs4_xattr_handlers,
73};
74
75static 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)
80 ret = pnfs_layoutcommit_inode(inode,
81 wbc->sync_mode == WB_SYNC_ALL);
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 */
90static void nfs4_evict_inode(struct inode *inode)
91{
92 truncate_inode_pages_final(&inode->i_data);
93 clear_inode(inode);
94 /* If we are holding a delegation, return it! */
95 nfs_inode_return_delegation_noreclaim(inode);
96 /* Note that above delegreturn would trigger pnfs return-on-close */
97 pnfs_return_layout(inode);
98 pnfs_destroy_layout(NFS_I(inode));
99 /* First call standard NFS clear_inode() code */
100 nfs_clear_inode(inode);
101}
102
103/*
104 * Get the superblock for the NFS4 root partition
105 */
106static struct dentry *
107nfs4_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->set_security = nfs_set_sb_security;
115
116 /* Get a volume representation */
117 server = nfs4_create_server(mount_info, &nfs_v4);
118 if (IS_ERR(server)) {
119 mntroot = ERR_CAST(server);
120 goto out;
121 }
122
123 mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);
124
125out:
126 return mntroot;
127}
128
129static 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
150struct nfs_referral_count {
151 struct list_head list;
152 const struct task_struct *task;
153 unsigned int referral_count;
154};
155
156static LIST_HEAD(nfs_referral_count_list);
157static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
158
159static 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
172static 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);
197out:
198 return ret;
199}
200
201static 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
216static 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
237struct dentry *nfs4_try_mount(int flags, const char *dev_name,
238 struct nfs_mount_info *mount_info,
239 struct nfs_subversion *nfs_mod)
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 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
256 dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
257 PTR_ERR_OR_ZERO(res),
258 IS_ERR(res) ? " [error]" : "");
259 return res;
260}
261
262static struct dentry *
263nfs4_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 = {
267 .fill_super = nfs_fill_super,
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
287 mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
288out:
289 nfs_free_fhandle(mount_info.mntfh);
290 return mntroot;
291}
292
293/*
294 * Create an NFS4 server record on referral traversal
295 */
296static 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);
314 dprintk("<-- nfs4_referral_mount() = %d%s\n",
315 PTR_ERR_OR_ZERO(res),
316 IS_ERR(res) ? " [error]" : "");
317 return res;
318}
319
320
321static int __init init_nfs_v4(void)
322{
323 int err;
324
325 err = nfs_dns_resolver_init();
326 if (err)
327 goto out;
328
329 err = nfs_idmap_init();
330 if (err)
331 goto out1;
332
333 err = nfs4_register_sysctl();
334 if (err)
335 goto out2;
336
337 register_nfs_version(&nfs_v4);
338 return 0;
339out2:
340 nfs_idmap_quit();
341out1:
342 nfs_dns_resolver_destroy();
343out:
344 return err;
345}
346
347static void __exit exit_nfs_v4(void)
348{
349 /* Not called in the _init(), conditionally loaded */
350 nfs4_pnfs_v3_ds_connect_unload();
351
352 unregister_nfs_version(&nfs_v4);
353 nfs4_unregister_sysctl();
354 nfs_idmap_quit();
355 nfs_dns_resolver_destroy();
356}
357
358MODULE_LICENSE("GPL");
359
360module_init(init_nfs_v4);
361module_exit(exit_nfs_v4);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
4 */
5#include <linux/init.h>
6#include <linux/module.h>
7#include <linux/nfs4_mount.h>
8#include <linux/nfs_fs.h>
9#include "delegation.h"
10#include "internal.h"
11#include "nfs4_fs.h"
12#include "nfs4idmap.h"
13#include "dns_resolve.h"
14#include "pnfs.h"
15#include "nfs.h"
16
17#define NFSDBG_FACILITY NFSDBG_VFS
18
19static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
20static void nfs4_evict_inode(struct inode *inode);
21static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
22 int flags, const char *dev_name, void *raw_data);
23static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
24 int flags, const char *dev_name, void *raw_data);
25static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
26 int flags, const char *dev_name, void *raw_data);
27
28static 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,
33 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
34};
35
36static 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,
41 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
42};
43
44struct 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,
49 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
50};
51
52static const struct super_operations nfs4_sops = {
53 .alloc_inode = nfs_alloc_inode,
54 .free_inode = nfs_free_inode,
55 .write_inode = nfs4_write_inode,
56 .drop_inode = nfs_drop_inode,
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
67struct 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,
72 .sops = &nfs4_sops,
73 .xattr = nfs4_xattr_handlers,
74};
75
76static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
77{
78 int ret = nfs_write_inode(inode, wbc);
79
80 if (ret == 0)
81 ret = pnfs_layoutcommit_inode(inode,
82 wbc->sync_mode == WB_SYNC_ALL);
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 */
91static void nfs4_evict_inode(struct inode *inode)
92{
93 truncate_inode_pages_final(&inode->i_data);
94 clear_inode(inode);
95 /* If we are holding a delegation, return it! */
96 nfs_inode_return_delegation_noreclaim(inode);
97 /* Note that above delegreturn would trigger pnfs return-on-close */
98 pnfs_return_layout(inode);
99 pnfs_destroy_layout(NFS_I(inode));
100 /* First call standard NFS clear_inode() code */
101 nfs_clear_inode(inode);
102}
103
104/*
105 * Get the superblock for the NFS4 root partition
106 */
107static struct dentry *
108nfs4_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
115 mount_info->set_security = nfs_set_sb_security;
116
117 /* Get a volume representation */
118 server = nfs4_create_server(mount_info, &nfs_v4);
119 if (IS_ERR(server)) {
120 mntroot = ERR_CAST(server);
121 goto out;
122 }
123
124 mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);
125
126out:
127 return mntroot;
128}
129
130static 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
151struct nfs_referral_count {
152 struct list_head list;
153 const struct task_struct *task;
154 unsigned int referral_count;
155};
156
157static LIST_HEAD(nfs_referral_count_list);
158static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
159
160static 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
173static 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);
198out:
199 return ret;
200}
201
202static 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
217static 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
238struct dentry *nfs4_try_mount(int flags, const char *dev_name,
239 struct nfs_mount_info *mount_info,
240 struct nfs_subversion *nfs_mod)
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
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
257 dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
258 PTR_ERR_OR_ZERO(res),
259 IS_ERR(res) ? " [error]" : "");
260 return res;
261}
262
263static struct dentry *
264nfs4_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 = {
268 .fill_super = nfs_fill_super,
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
288 mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
289out:
290 nfs_free_fhandle(mount_info.mntfh);
291 return mntroot;
292}
293
294/*
295 * Create an NFS4 server record on referral traversal
296 */
297static 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);
315 dprintk("<-- nfs4_referral_mount() = %d%s\n",
316 PTR_ERR_OR_ZERO(res),
317 IS_ERR(res) ? " [error]" : "");
318 return res;
319}
320
321
322static int __init init_nfs_v4(void)
323{
324 int err;
325
326 err = nfs_dns_resolver_init();
327 if (err)
328 goto out;
329
330 err = nfs_idmap_init();
331 if (err)
332 goto out1;
333
334 err = nfs4_register_sysctl();
335 if (err)
336 goto out2;
337
338 register_nfs_version(&nfs_v4);
339 return 0;
340out2:
341 nfs_idmap_quit();
342out1:
343 nfs_dns_resolver_destroy();
344out:
345 return err;
346}
347
348static void __exit exit_nfs_v4(void)
349{
350 /* Not called in the _init(), conditionally loaded */
351 nfs4_pnfs_v3_ds_connect_unload();
352
353 unregister_nfs_version(&nfs_v4);
354 nfs4_unregister_sysctl();
355 nfs_idmap_quit();
356 nfs_dns_resolver_destroy();
357}
358
359MODULE_LICENSE("GPL");
360
361module_init(init_nfs_v4);
362module_exit(exit_nfs_v4);