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8#include <linux/slab.h>
9#include <linux/string.h>
10#include <linux/dcache.h>
11#include <linux/sunrpc/sched.h>
12#include <linux/sunrpc/clnt.h>
13#include <linux/nfs_fs.h>
14#include <linux/sched.h>
15#include <linux/wait.h>
16#include <linux/namei.h>
17#include <linux/fsnotify.h>
18
19#include "internal.h"
20#include "nfs4_fs.h"
21#include "iostat.h"
22#include "delegation.h"
23
24#include "nfstrace.h"
25
26
27
28
29
30static void
31nfs_free_unlinkdata(struct nfs_unlinkdata *data)
32{
33 iput(data->dir);
34 put_rpccred(data->cred);
35 kfree(data->args.name.name);
36 kfree(data);
37}
38
39#define NAME_ALLOC_LEN(len) ((len+16) & ~15)
40
41
42
43
44
45static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
46{
47 char *str;
48 int len = dentry->d_name.len;
49
50 str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
51 if (!str)
52 return -ENOMEM;
53 data->args.name.len = len;
54 data->args.name.name = str;
55 return 0;
56}
57
58static void nfs_free_dname(struct nfs_unlinkdata *data)
59{
60 kfree(data->args.name.name);
61 data->args.name.name = NULL;
62 data->args.name.len = 0;
63}
64
65static void nfs_dec_sillycount(struct inode *dir)
66{
67 struct nfs_inode *nfsi = NFS_I(dir);
68 if (atomic_dec_return(&nfsi->silly_count) == 1)
69 wake_up(&nfsi->waitqueue);
70}
71
72
73
74
75
76
77
78static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
79{
80 struct nfs_unlinkdata *data = calldata;
81 struct inode *dir = data->dir;
82
83 trace_nfs_sillyrename_unlink(data, task->tk_status);
84 if (!NFS_PROTO(dir)->unlink_done(task, dir))
85 rpc_restart_call_prepare(task);
86}
87
88
89
90
91
92
93
94
95static void nfs_async_unlink_release(void *calldata)
96{
97 struct nfs_unlinkdata *data = calldata;
98 struct super_block *sb = data->dir->i_sb;
99
100 nfs_dec_sillycount(data->dir);
101 nfs_free_unlinkdata(data);
102 nfs_sb_deactive(sb);
103}
104
105static void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
106{
107 struct nfs_unlinkdata *data = calldata;
108 NFS_PROTO(data->dir)->unlink_rpc_prepare(task, data);
109}
110
111static const struct rpc_call_ops nfs_unlink_ops = {
112 .rpc_call_done = nfs_async_unlink_done,
113 .rpc_release = nfs_async_unlink_release,
114 .rpc_call_prepare = nfs_unlink_prepare,
115};
116
117static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
118{
119 struct rpc_message msg = {
120 .rpc_argp = &data->args,
121 .rpc_resp = &data->res,
122 .rpc_cred = data->cred,
123 };
124 struct rpc_task_setup task_setup_data = {
125 .rpc_message = &msg,
126 .callback_ops = &nfs_unlink_ops,
127 .callback_data = data,
128 .workqueue = nfsiod_workqueue,
129 .flags = RPC_TASK_ASYNC,
130 };
131 struct rpc_task *task;
132 struct dentry *alias;
133
134 alias = d_lookup(parent, &data->args.name);
135 if (alias != NULL) {
136 int ret;
137 void *devname_garbage = NULL;
138
139
140
141
142
143 nfs_free_dname(data);
144 ret = nfs_copy_dname(alias, data);
145 spin_lock(&alias->d_lock);
146 if (ret == 0 && d_really_is_positive(alias) &&
147 !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
148 devname_garbage = alias->d_fsdata;
149 alias->d_fsdata = data;
150 alias->d_flags |= DCACHE_NFSFS_RENAMED;
151 ret = 1;
152 } else
153 ret = 0;
154 spin_unlock(&alias->d_lock);
155 nfs_dec_sillycount(dir);
156 dput(alias);
157
158
159
160
161
162 kfree(devname_garbage);
163 return ret;
164 }
165 data->dir = igrab(dir);
166 if (!data->dir) {
167 nfs_dec_sillycount(dir);
168 return 0;
169 }
170 nfs_sb_active(dir->i_sb);
171 data->args.fh = NFS_FH(dir);
172 nfs_fattr_init(data->res.dir_attr);
173
174 NFS_PROTO(dir)->unlink_setup(&msg, dir);
175
176 task_setup_data.rpc_client = NFS_CLIENT(dir);
177 task = rpc_run_task(&task_setup_data);
178 if (!IS_ERR(task))
179 rpc_put_task_async(task);
180 return 1;
181}
182
183static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
184{
185 struct dentry *parent;
186 struct inode *dir;
187 int ret = 0;
188
189
190 parent = dget_parent(dentry);
191 if (parent == NULL)
192 goto out_free;
193 dir = d_inode(parent);
194
195 spin_lock(&dir->i_lock);
196 if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
197
198 hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
199 spin_unlock(&dir->i_lock);
200 ret = 1;
201 goto out_dput;
202 }
203 spin_unlock(&dir->i_lock);
204 ret = nfs_do_call_unlink(parent, dir, data);
205out_dput:
206 dput(parent);
207out_free:
208 return ret;
209}
210
211void nfs_wait_on_sillyrename(struct dentry *dentry)
212{
213 struct nfs_inode *nfsi = NFS_I(d_inode(dentry));
214
215 wait_event(nfsi->waitqueue, atomic_read(&nfsi->silly_count) <= 1);
216}
217
218void nfs_block_sillyrename(struct dentry *dentry)
219{
220 struct nfs_inode *nfsi = NFS_I(d_inode(dentry));
221
222 wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
223}
224
225void nfs_unblock_sillyrename(struct dentry *dentry)
226{
227 struct inode *dir = d_inode(dentry);
228 struct nfs_inode *nfsi = NFS_I(dir);
229 struct nfs_unlinkdata *data;
230
231 atomic_inc(&nfsi->silly_count);
232 spin_lock(&dir->i_lock);
233 while (!hlist_empty(&nfsi->silly_list)) {
234 if (!atomic_inc_not_zero(&nfsi->silly_count))
235 break;
236 data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
237 hlist_del(&data->list);
238 spin_unlock(&dir->i_lock);
239 if (nfs_do_call_unlink(dentry, dir, data) == 0)
240 nfs_free_unlinkdata(data);
241 spin_lock(&dir->i_lock);
242 }
243 spin_unlock(&dir->i_lock);
244}
245
246
247
248
249
250
251static int
252nfs_async_unlink(struct inode *dir, struct dentry *dentry)
253{
254 struct nfs_unlinkdata *data;
255 int status = -ENOMEM;
256 void *devname_garbage = NULL;
257
258 data = kzalloc(sizeof(*data), GFP_KERNEL);
259 if (data == NULL)
260 goto out;
261
262 data->cred = rpc_lookup_cred();
263 if (IS_ERR(data->cred)) {
264 status = PTR_ERR(data->cred);
265 goto out_free;
266 }
267 data->res.dir_attr = &data->dir_attr;
268
269 status = -EBUSY;
270 spin_lock(&dentry->d_lock);
271 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
272 goto out_unlock;
273 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
274 devname_garbage = dentry->d_fsdata;
275 dentry->d_fsdata = data;
276 spin_unlock(&dentry->d_lock);
277
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280
281
282 kfree(devname_garbage);
283 return 0;
284out_unlock:
285 spin_unlock(&dentry->d_lock);
286 put_rpccred(data->cred);
287out_free:
288 kfree(data);
289out:
290 return status;
291}
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301
302void
303nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
304{
305 struct nfs_unlinkdata *data = NULL;
306
307 spin_lock(&dentry->d_lock);
308 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
309 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
310 data = dentry->d_fsdata;
311 dentry->d_fsdata = NULL;
312 }
313 spin_unlock(&dentry->d_lock);
314
315 if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
316 nfs_free_unlinkdata(data);
317}
318
319
320static void
321nfs_cancel_async_unlink(struct dentry *dentry)
322{
323 spin_lock(&dentry->d_lock);
324 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
325 struct nfs_unlinkdata *data = dentry->d_fsdata;
326
327 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
328 dentry->d_fsdata = NULL;
329 spin_unlock(&dentry->d_lock);
330 nfs_free_unlinkdata(data);
331 return;
332 }
333 spin_unlock(&dentry->d_lock);
334}
335
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341
342
343static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
344{
345 struct nfs_renamedata *data = calldata;
346 struct inode *old_dir = data->old_dir;
347 struct inode *new_dir = data->new_dir;
348 struct dentry *old_dentry = data->old_dentry;
349
350 trace_nfs_sillyrename_rename(old_dir, old_dentry,
351 new_dir, data->new_dentry, task->tk_status);
352 if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
353 rpc_restart_call_prepare(task);
354 return;
355 }
356
357 if (data->complete)
358 data->complete(task, data);
359}
360
361
362
363
364
365static void nfs_async_rename_release(void *calldata)
366{
367 struct nfs_renamedata *data = calldata;
368 struct super_block *sb = data->old_dir->i_sb;
369
370 if (d_really_is_positive(data->old_dentry))
371 nfs_mark_for_revalidate(d_inode(data->old_dentry));
372
373 dput(data->old_dentry);
374 dput(data->new_dentry);
375 iput(data->old_dir);
376 iput(data->new_dir);
377 nfs_sb_deactive(sb);
378 put_rpccred(data->cred);
379 kfree(data);
380}
381
382static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
383{
384 struct nfs_renamedata *data = calldata;
385 NFS_PROTO(data->old_dir)->rename_rpc_prepare(task, data);
386}
387
388static const struct rpc_call_ops nfs_rename_ops = {
389 .rpc_call_done = nfs_async_rename_done,
390 .rpc_release = nfs_async_rename_release,
391 .rpc_call_prepare = nfs_rename_prepare,
392};
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401
402
403struct rpc_task *
404nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
405 struct dentry *old_dentry, struct dentry *new_dentry,
406 void (*complete)(struct rpc_task *, struct nfs_renamedata *))
407{
408 struct nfs_renamedata *data;
409 struct rpc_message msg = { };
410 struct rpc_task_setup task_setup_data = {
411 .rpc_message = &msg,
412 .callback_ops = &nfs_rename_ops,
413 .workqueue = nfsiod_workqueue,
414 .rpc_client = NFS_CLIENT(old_dir),
415 .flags = RPC_TASK_ASYNC,
416 };
417
418 data = kzalloc(sizeof(*data), GFP_KERNEL);
419 if (data == NULL)
420 return ERR_PTR(-ENOMEM);
421 task_setup_data.callback_data = data;
422
423 data->cred = rpc_lookup_cred();
424 if (IS_ERR(data->cred)) {
425 struct rpc_task *task = ERR_CAST(data->cred);
426 kfree(data);
427 return task;
428 }
429
430 msg.rpc_argp = &data->args;
431 msg.rpc_resp = &data->res;
432 msg.rpc_cred = data->cred;
433
434
435 data->old_dir = old_dir;
436 ihold(old_dir);
437 data->new_dir = new_dir;
438 ihold(new_dir);
439 data->old_dentry = dget(old_dentry);
440 data->new_dentry = dget(new_dentry);
441 nfs_fattr_init(&data->old_fattr);
442 nfs_fattr_init(&data->new_fattr);
443 data->complete = complete;
444
445
446 data->args.old_dir = NFS_FH(old_dir);
447 data->args.old_name = &old_dentry->d_name;
448 data->args.new_dir = NFS_FH(new_dir);
449 data->args.new_name = &new_dentry->d_name;
450
451
452 data->res.old_fattr = &data->old_fattr;
453 data->res.new_fattr = &data->new_fattr;
454
455 nfs_sb_active(old_dir->i_sb);
456
457 NFS_PROTO(data->old_dir)->rename_setup(&msg, old_dir);
458
459 return rpc_run_task(&task_setup_data);
460}
461
462
463
464
465
466static void
467nfs_complete_sillyrename(struct rpc_task *task, struct nfs_renamedata *data)
468{
469 struct dentry *dentry = data->old_dentry;
470
471 if (task->tk_status != 0) {
472 nfs_cancel_async_unlink(dentry);
473 return;
474 }
475
476
477
478
479
480 fsnotify_nameremove(dentry, 0);
481}
482
483#define SILLYNAME_PREFIX ".nfs"
484#define SILLYNAME_PREFIX_LEN ((unsigned)sizeof(SILLYNAME_PREFIX) - 1)
485#define SILLYNAME_FILEID_LEN ((unsigned)sizeof(u64) << 1)
486#define SILLYNAME_COUNTER_LEN ((unsigned)sizeof(unsigned int) << 1)
487#define SILLYNAME_LEN (SILLYNAME_PREFIX_LEN + \
488 SILLYNAME_FILEID_LEN + \
489 SILLYNAME_COUNTER_LEN)
490
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511
512int
513nfs_sillyrename(struct inode *dir, struct dentry *dentry)
514{
515 static unsigned int sillycounter;
516 unsigned char silly[SILLYNAME_LEN + 1];
517 unsigned long long fileid;
518 struct dentry *sdentry;
519 struct rpc_task *task;
520 int error = -EBUSY;
521
522 dfprintk(VFS, "NFS: silly-rename(%pd2, ct=%d)\n",
523 dentry, d_count(dentry));
524 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
525
526
527
528
529 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
530 goto out;
531
532 fileid = NFS_FILEID(d_inode(dentry));
533
534
535 NFS_PROTO(d_inode(dentry))->return_delegation(d_inode(dentry));
536
537 sdentry = NULL;
538 do {
539 int slen;
540 dput(sdentry);
541 sillycounter++;
542 slen = scnprintf(silly, sizeof(silly),
543 SILLYNAME_PREFIX "%0*llx%0*x",
544 SILLYNAME_FILEID_LEN, fileid,
545 SILLYNAME_COUNTER_LEN, sillycounter);
546
547 dfprintk(VFS, "NFS: trying to rename %pd to %s\n",
548 dentry, silly);
549
550 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
551
552
553
554
555 if (IS_ERR(sdentry))
556 goto out;
557 } while (d_inode(sdentry) != NULL);
558
559
560
561
562 error = nfs_async_unlink(dir, dentry);
563 if (error)
564 goto out_dput;
565
566
567 error = nfs_copy_dname(sdentry,
568 (struct nfs_unlinkdata *)dentry->d_fsdata);
569 if (error) {
570 nfs_cancel_async_unlink(dentry);
571 goto out_dput;
572 }
573
574
575 task = nfs_async_rename(dir, dir, dentry, sdentry,
576 nfs_complete_sillyrename);
577 if (IS_ERR(task)) {
578 error = -EBUSY;
579 nfs_cancel_async_unlink(dentry);
580 goto out_dput;
581 }
582
583
584 error = rpc_wait_for_completion_task(task);
585 if (error == 0)
586 error = task->tk_status;
587 switch (error) {
588 case 0:
589
590 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
591 d_move(dentry, sdentry);
592 break;
593 case -ERESTARTSYS:
594
595
596 d_drop(dentry);
597 d_drop(sdentry);
598 }
599 rpc_put_task(task);
600out_dput:
601 dput(sdentry);
602out:
603 return error;
604}
605