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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/mount.h>
8#include <linux/nfs4_mount.h>
9#include <linux/nfs_fs.h>
10#include <linux/nfs_ssc.h>
11#include "delegation.h"
12#include "internal.h"
13#include "nfs4_fs.h"
14#include "nfs4idmap.h"
15#include "dns_resolve.h"
16#include "pnfs.h"
17#include "nfs.h"
18
19#define NFSDBG_FACILITY NFSDBG_VFS
20
21static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
22static void nfs4_evict_inode(struct inode *inode);
23
24static const struct super_operations nfs4_sops = {
25 .alloc_inode = nfs_alloc_inode,
26 .free_inode = nfs_free_inode,
27 .write_inode = nfs4_write_inode,
28 .drop_inode = nfs_drop_inode,
29 .statfs = nfs_statfs,
30 .evict_inode = nfs4_evict_inode,
31 .umount_begin = nfs_umount_begin,
32 .show_options = nfs_show_options,
33 .show_devname = nfs_show_devname,
34 .show_path = nfs_show_path,
35 .show_stats = nfs_show_stats,
36};
37
38struct nfs_subversion nfs_v4 = {
39 .owner = THIS_MODULE,
40 .nfs_fs = &nfs4_fs_type,
41 .rpc_vers = &nfs_version4,
42 .rpc_ops = &nfs_v4_clientops,
43 .sops = &nfs4_sops,
44 .xattr = nfs4_xattr_handlers,
45};
46
47static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
48{
49 int ret = nfs_write_inode(inode, wbc);
50
51 if (ret == 0)
52 ret = pnfs_layoutcommit_inode(inode,
53 wbc->sync_mode == WB_SYNC_ALL);
54 return ret;
55}
56
57/*
58 * Clean out any remaining NFSv4 state that might be left over due
59 * to open() calls that passed nfs_atomic_lookup, but failed to call
60 * nfs_open().
61 */
62static void nfs4_evict_inode(struct inode *inode)
63{
64 truncate_inode_pages_final(&inode->i_data);
65 clear_inode(inode);
66 /* If we are holding a delegation, return and free it */
67 nfs_inode_evict_delegation(inode);
68 /* Note that above delegreturn would trigger pnfs return-on-close */
69 pnfs_return_layout(inode);
70 pnfs_destroy_layout_final(NFS_I(inode));
71 /* First call standard NFS clear_inode() code */
72 nfs_clear_inode(inode);
73 nfs4_xattr_cache_zap(inode);
74}
75
76struct nfs_referral_count {
77 struct list_head list;
78 const struct task_struct *task;
79 unsigned int referral_count;
80};
81
82static LIST_HEAD(nfs_referral_count_list);
83static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
84
85static struct nfs_referral_count *nfs_find_referral_count(void)
86{
87 struct nfs_referral_count *p;
88
89 list_for_each_entry(p, &nfs_referral_count_list, list) {
90 if (p->task == current)
91 return p;
92 }
93 return NULL;
94}
95
96#define NFS_MAX_NESTED_REFERRALS 2
97
98static int nfs_referral_loop_protect(void)
99{
100 struct nfs_referral_count *p, *new;
101 int ret = -ENOMEM;
102
103 new = kmalloc(sizeof(*new), GFP_KERNEL);
104 if (!new)
105 goto out;
106 new->task = current;
107 new->referral_count = 1;
108
109 ret = 0;
110 spin_lock(&nfs_referral_count_list_lock);
111 p = nfs_find_referral_count();
112 if (p != NULL) {
113 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
114 ret = -ELOOP;
115 else
116 p->referral_count++;
117 } else {
118 list_add(&new->list, &nfs_referral_count_list);
119 new = NULL;
120 }
121 spin_unlock(&nfs_referral_count_list_lock);
122 kfree(new);
123out:
124 return ret;
125}
126
127static void nfs_referral_loop_unprotect(void)
128{
129 struct nfs_referral_count *p;
130
131 spin_lock(&nfs_referral_count_list_lock);
132 p = nfs_find_referral_count();
133 p->referral_count--;
134 if (p->referral_count == 0)
135 list_del(&p->list);
136 else
137 p = NULL;
138 spin_unlock(&nfs_referral_count_list_lock);
139 kfree(p);
140}
141
142static int do_nfs4_mount(struct nfs_server *server,
143 struct fs_context *fc,
144 const char *hostname,
145 const char *export_path)
146{
147 struct nfs_fs_context *root_ctx;
148 struct nfs_fs_context *ctx;
149 struct fs_context *root_fc;
150 struct vfsmount *root_mnt;
151 struct dentry *dentry;
152 size_t len;
153 int ret;
154
155 struct fs_parameter param = {
156 .key = "source",
157 .type = fs_value_is_string,
158 .dirfd = -1,
159 };
160
161 struct fs_parameter param_fsc = {
162 .key = "fsc",
163 .type = fs_value_is_string,
164 .dirfd = -1,
165 };
166
167 if (IS_ERR(server))
168 return PTR_ERR(server);
169
170 root_fc = vfs_dup_fs_context(fc);
171 if (IS_ERR(root_fc)) {
172 nfs_free_server(server);
173 return PTR_ERR(root_fc);
174 }
175 kfree(root_fc->source);
176 root_fc->source = NULL;
177
178 ctx = nfs_fc2context(fc);
179 root_ctx = nfs_fc2context(root_fc);
180 root_ctx->internal = true;
181 root_ctx->server = server;
182
183 if (ctx->fscache_uniq) {
184 len = strlen(ctx->fscache_uniq);
185 param_fsc.size = len;
186 param_fsc.string = kmemdup_nul(ctx->fscache_uniq, len, GFP_KERNEL);
187 if (param_fsc.string == NULL) {
188 put_fs_context(root_fc);
189 return -ENOMEM;
190 }
191 ret = vfs_parse_fs_param(root_fc, ¶m_fsc);
192 kfree(param_fsc.string);
193 if (ret < 0) {
194 put_fs_context(root_fc);
195 return ret;
196 }
197 }
198 /* We leave export_path unset as it's not used to find the root. */
199
200 len = strlen(hostname) + 5;
201 param.string = kmalloc(len, GFP_KERNEL);
202 if (param.string == NULL) {
203 put_fs_context(root_fc);
204 return -ENOMEM;
205 }
206
207 /* Does hostname needs to be enclosed in brackets? */
208 if (strchr(hostname, ':'))
209 param.size = snprintf(param.string, len, "[%s]:/", hostname);
210 else
211 param.size = snprintf(param.string, len, "%s:/", hostname);
212 ret = vfs_parse_fs_param(root_fc, ¶m);
213 kfree(param.string);
214 if (ret < 0) {
215 put_fs_context(root_fc);
216 return ret;
217 }
218 root_mnt = fc_mount(root_fc);
219 put_fs_context(root_fc);
220
221 if (IS_ERR(root_mnt))
222 return PTR_ERR(root_mnt);
223
224 ret = nfs_referral_loop_protect();
225 if (ret) {
226 mntput(root_mnt);
227 return ret;
228 }
229
230 dentry = mount_subtree(root_mnt, export_path);
231 nfs_referral_loop_unprotect();
232
233 if (IS_ERR(dentry))
234 return PTR_ERR(dentry);
235
236 fc->root = dentry;
237 return 0;
238}
239
240int nfs4_try_get_tree(struct fs_context *fc)
241{
242 struct nfs_fs_context *ctx = nfs_fc2context(fc);
243 int err;
244
245 dfprintk(MOUNT, "--> nfs4_try_get_tree()\n");
246
247 /* We create a mount for the server's root, walk to the requested
248 * location and then create another mount for that.
249 */
250 err= do_nfs4_mount(nfs4_create_server(fc),
251 fc, ctx->nfs_server.hostname,
252 ctx->nfs_server.export_path);
253 if (err) {
254 nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
255 dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err);
256 } else {
257 dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n");
258 }
259 return err;
260}
261
262/*
263 * Create an NFS4 server record on referral traversal
264 */
265int nfs4_get_referral_tree(struct fs_context *fc)
266{
267 struct nfs_fs_context *ctx = nfs_fc2context(fc);
268 int err;
269
270 dprintk("--> nfs4_referral_mount()\n");
271
272 /* create a new volume representation */
273 err = do_nfs4_mount(nfs4_create_referral_server(fc),
274 fc, ctx->nfs_server.hostname,
275 ctx->nfs_server.export_path);
276 if (err) {
277 nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
278 dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err);
279 } else {
280 dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n");
281 }
282 return err;
283}
284
285static int __init init_nfs_v4(void)
286{
287 int err;
288
289 err = nfs_dns_resolver_init();
290 if (err)
291 goto out;
292
293 err = nfs_idmap_init();
294 if (err)
295 goto out1;
296
297#ifdef CONFIG_NFS_V4_2
298 err = nfs4_xattr_cache_init();
299 if (err)
300 goto out2;
301#endif
302
303 err = nfs4_register_sysctl();
304 if (err)
305 goto out2;
306
307#ifdef CONFIG_NFS_V4_2
308 nfs42_ssc_register_ops();
309#endif
310 register_nfs_version(&nfs_v4);
311 return 0;
312out2:
313 nfs_idmap_quit();
314out1:
315 nfs_dns_resolver_destroy();
316out:
317 return err;
318}
319
320static void __exit exit_nfs_v4(void)
321{
322 /* Not called in the _init(), conditionally loaded */
323 nfs4_pnfs_v3_ds_connect_unload();
324
325 unregister_nfs_version(&nfs_v4);
326#ifdef CONFIG_NFS_V4_2
327 nfs4_xattr_cache_exit();
328 nfs42_ssc_unregister_ops();
329#endif
330 nfs4_unregister_sysctl();
331 nfs_idmap_quit();
332 nfs_dns_resolver_destroy();
333}
334
335MODULE_DESCRIPTION("NFSv4 client support");
336MODULE_LICENSE("GPL");
337
338module_init(init_nfs_v4);
339module_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);