drm/nouveau: unpin pushbuffer bo before destroying it
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nfs / unlink.c
blob3f79c77153b8fe827cd24310209301e0132b96ad
1 /*
2 * linux/fs/nfs/unlink.c
4 * nfs sillydelete handling
6 */
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>
18 #include "internal.h"
19 #include "nfs4_fs.h"
20 #include "iostat.h"
21 #include "delegation.h"
23 /**
24 * nfs_free_unlinkdata - release data from a sillydelete operation.
25 * @data: pointer to unlink structure.
27 static void
28 nfs_free_unlinkdata(struct nfs_unlinkdata *data)
30 iput(data->dir);
31 put_rpccred(data->cred);
32 kfree(data->args.name.name);
33 kfree(data);
36 #define NAME_ALLOC_LEN(len) ((len+16) & ~15)
37 /**
38 * nfs_copy_dname - copy dentry name to data structure
39 * @dentry: pointer to dentry
40 * @data: nfs_unlinkdata
42 static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
44 char *str;
45 int len = dentry->d_name.len;
47 str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
48 if (!str)
49 return -ENOMEM;
50 data->args.name.len = len;
51 data->args.name.name = str;
52 return 0;
55 static void nfs_free_dname(struct nfs_unlinkdata *data)
57 kfree(data->args.name.name);
58 data->args.name.name = NULL;
59 data->args.name.len = 0;
62 static void nfs_dec_sillycount(struct inode *dir)
64 struct nfs_inode *nfsi = NFS_I(dir);
65 if (atomic_dec_return(&nfsi->silly_count) == 1)
66 wake_up(&nfsi->waitqueue);
69 /**
70 * nfs_async_unlink_done - Sillydelete post-processing
71 * @task: rpc_task of the sillydelete
73 * Do the directory attribute update.
75 static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
77 struct nfs_unlinkdata *data = calldata;
78 struct inode *dir = data->dir;
80 if (!NFS_PROTO(dir)->unlink_done(task, dir))
81 rpc_restart_call_prepare(task);
84 /**
85 * nfs_async_unlink_release - Release the sillydelete data.
86 * @task: rpc_task of the sillydelete
88 * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
89 * rpc_task would be freed too.
91 static void nfs_async_unlink_release(void *calldata)
93 struct nfs_unlinkdata *data = calldata;
94 struct super_block *sb = data->dir->i_sb;
96 nfs_dec_sillycount(data->dir);
97 nfs_free_unlinkdata(data);
98 nfs_sb_deactive_async(sb);
101 static void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
103 struct nfs_unlinkdata *data = calldata;
104 NFS_PROTO(data->dir)->unlink_rpc_prepare(task, data);
107 static const struct rpc_call_ops nfs_unlink_ops = {
108 .rpc_call_done = nfs_async_unlink_done,
109 .rpc_release = nfs_async_unlink_release,
110 .rpc_call_prepare = nfs_unlink_prepare,
113 static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
115 struct rpc_message msg = {
116 .rpc_argp = &data->args,
117 .rpc_resp = &data->res,
118 .rpc_cred = data->cred,
120 struct rpc_task_setup task_setup_data = {
121 .rpc_message = &msg,
122 .callback_ops = &nfs_unlink_ops,
123 .callback_data = data,
124 .workqueue = nfsiod_workqueue,
125 .flags = RPC_TASK_ASYNC,
127 struct rpc_task *task;
128 struct dentry *alias;
130 alias = d_lookup(parent, &data->args.name);
131 if (alias != NULL) {
132 int ret;
133 void *devname_garbage = NULL;
136 * Hey, we raced with lookup... See if we need to transfer
137 * the sillyrename information to the aliased dentry.
139 nfs_free_dname(data);
140 ret = nfs_copy_dname(alias, data);
141 spin_lock(&alias->d_lock);
142 if (ret == 0 && alias->d_inode != NULL &&
143 !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
144 devname_garbage = alias->d_fsdata;
145 alias->d_fsdata = data;
146 alias->d_flags |= DCACHE_NFSFS_RENAMED;
147 ret = 1;
148 } else
149 ret = 0;
150 spin_unlock(&alias->d_lock);
151 nfs_dec_sillycount(dir);
152 dput(alias);
154 * If we'd displaced old cached devname, free it. At that
155 * point dentry is definitely not a root, so we won't need
156 * that anymore.
158 kfree(devname_garbage);
159 return ret;
161 data->dir = igrab(dir);
162 if (!data->dir) {
163 nfs_dec_sillycount(dir);
164 return 0;
166 nfs_sb_active(dir->i_sb);
167 data->args.fh = NFS_FH(dir);
168 nfs_fattr_init(data->res.dir_attr);
170 NFS_PROTO(dir)->unlink_setup(&msg, dir);
172 task_setup_data.rpc_client = NFS_CLIENT(dir);
173 task = rpc_run_task(&task_setup_data);
174 if (!IS_ERR(task))
175 rpc_put_task_async(task);
176 return 1;
179 static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
181 struct dentry *parent;
182 struct inode *dir;
183 int ret = 0;
186 parent = dget_parent(dentry);
187 if (parent == NULL)
188 goto out_free;
189 dir = parent->d_inode;
190 /* Non-exclusive lock protects against concurrent lookup() calls */
191 spin_lock(&dir->i_lock);
192 if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
193 /* Deferred delete */
194 hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
195 spin_unlock(&dir->i_lock);
196 ret = 1;
197 goto out_dput;
199 spin_unlock(&dir->i_lock);
200 ret = nfs_do_call_unlink(parent, dir, data);
201 out_dput:
202 dput(parent);
203 out_free:
204 return ret;
207 void nfs_block_sillyrename(struct dentry *dentry)
209 struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
211 wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
214 void nfs_unblock_sillyrename(struct dentry *dentry)
216 struct inode *dir = dentry->d_inode;
217 struct nfs_inode *nfsi = NFS_I(dir);
218 struct nfs_unlinkdata *data;
220 atomic_inc(&nfsi->silly_count);
221 spin_lock(&dir->i_lock);
222 while (!hlist_empty(&nfsi->silly_list)) {
223 if (!atomic_inc_not_zero(&nfsi->silly_count))
224 break;
225 data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
226 hlist_del(&data->list);
227 spin_unlock(&dir->i_lock);
228 if (nfs_do_call_unlink(dentry, dir, data) == 0)
229 nfs_free_unlinkdata(data);
230 spin_lock(&dir->i_lock);
232 spin_unlock(&dir->i_lock);
236 * nfs_async_unlink - asynchronous unlinking of a file
237 * @dir: parent directory of dentry
238 * @dentry: dentry to unlink
240 static int
241 nfs_async_unlink(struct inode *dir, struct dentry *dentry)
243 struct nfs_unlinkdata *data;
244 int status = -ENOMEM;
245 void *devname_garbage = NULL;
247 data = kzalloc(sizeof(*data), GFP_KERNEL);
248 if (data == NULL)
249 goto out;
251 data->cred = rpc_lookup_cred();
252 if (IS_ERR(data->cred)) {
253 status = PTR_ERR(data->cred);
254 goto out_free;
256 data->res.dir_attr = &data->dir_attr;
258 status = -EBUSY;
259 spin_lock(&dentry->d_lock);
260 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
261 goto out_unlock;
262 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
263 devname_garbage = dentry->d_fsdata;
264 dentry->d_fsdata = data;
265 spin_unlock(&dentry->d_lock);
267 * If we'd displaced old cached devname, free it. At that
268 * point dentry is definitely not a root, so we won't need
269 * that anymore.
271 if (devname_garbage)
272 kfree(devname_garbage);
273 return 0;
274 out_unlock:
275 spin_unlock(&dentry->d_lock);
276 put_rpccred(data->cred);
277 out_free:
278 kfree(data);
279 out:
280 return status;
284 * nfs_complete_unlink - Initialize completion of the sillydelete
285 * @dentry: dentry to delete
286 * @inode: inode
288 * Since we're most likely to be called by dentry_iput(), we
289 * only use the dentry to find the sillydelete. We then copy the name
290 * into the qstr.
292 void
293 nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
295 struct nfs_unlinkdata *data = NULL;
297 spin_lock(&dentry->d_lock);
298 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
299 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
300 data = dentry->d_fsdata;
301 dentry->d_fsdata = NULL;
303 spin_unlock(&dentry->d_lock);
305 if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
306 nfs_free_unlinkdata(data);
309 /* Cancel a queued async unlink. Called when a sillyrename run fails. */
310 static void
311 nfs_cancel_async_unlink(struct dentry *dentry)
313 spin_lock(&dentry->d_lock);
314 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
315 struct nfs_unlinkdata *data = dentry->d_fsdata;
317 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
318 dentry->d_fsdata = NULL;
319 spin_unlock(&dentry->d_lock);
320 nfs_free_unlinkdata(data);
321 return;
323 spin_unlock(&dentry->d_lock);
327 * nfs_async_rename_done - Sillyrename post-processing
328 * @task: rpc_task of the sillyrename
329 * @calldata: nfs_renamedata for the sillyrename
331 * Do the directory attribute updates and the d_move
333 static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
335 struct nfs_renamedata *data = calldata;
336 struct inode *old_dir = data->old_dir;
337 struct inode *new_dir = data->new_dir;
338 struct dentry *old_dentry = data->old_dentry;
339 struct dentry *new_dentry = data->new_dentry;
341 if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
342 rpc_restart_call_prepare(task);
343 return;
346 if (task->tk_status != 0) {
347 nfs_cancel_async_unlink(old_dentry);
348 return;
351 d_drop(old_dentry);
352 d_drop(new_dentry);
356 * nfs_async_rename_release - Release the sillyrename data.
357 * @calldata: the struct nfs_renamedata to be released
359 static void nfs_async_rename_release(void *calldata)
361 struct nfs_renamedata *data = calldata;
362 struct super_block *sb = data->old_dir->i_sb;
364 if (data->old_dentry->d_inode)
365 nfs_mark_for_revalidate(data->old_dentry->d_inode);
367 dput(data->old_dentry);
368 dput(data->new_dentry);
369 iput(data->old_dir);
370 iput(data->new_dir);
371 nfs_sb_deactive(sb);
372 put_rpccred(data->cred);
373 kfree(data);
376 static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
378 struct nfs_renamedata *data = calldata;
379 NFS_PROTO(data->old_dir)->rename_rpc_prepare(task, data);
382 static const struct rpc_call_ops nfs_rename_ops = {
383 .rpc_call_done = nfs_async_rename_done,
384 .rpc_release = nfs_async_rename_release,
385 .rpc_call_prepare = nfs_rename_prepare,
389 * nfs_async_rename - perform an asynchronous rename operation
390 * @old_dir: directory that currently holds the dentry to be renamed
391 * @new_dir: target directory for the rename
392 * @old_dentry: original dentry to be renamed
393 * @new_dentry: dentry to which the old_dentry should be renamed
395 * It's expected that valid references to the dentries and inodes are held
397 static struct rpc_task *
398 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
399 struct dentry *old_dentry, struct dentry *new_dentry)
401 struct nfs_renamedata *data;
402 struct rpc_message msg = { };
403 struct rpc_task_setup task_setup_data = {
404 .rpc_message = &msg,
405 .callback_ops = &nfs_rename_ops,
406 .workqueue = nfsiod_workqueue,
407 .rpc_client = NFS_CLIENT(old_dir),
408 .flags = RPC_TASK_ASYNC,
411 data = kzalloc(sizeof(*data), GFP_KERNEL);
412 if (data == NULL)
413 return ERR_PTR(-ENOMEM);
414 task_setup_data.callback_data = data;
416 data->cred = rpc_lookup_cred();
417 if (IS_ERR(data->cred)) {
418 struct rpc_task *task = ERR_CAST(data->cred);
419 kfree(data);
420 return task;
423 msg.rpc_argp = &data->args;
424 msg.rpc_resp = &data->res;
425 msg.rpc_cred = data->cred;
427 /* set up nfs_renamedata */
428 data->old_dir = old_dir;
429 ihold(old_dir);
430 data->new_dir = new_dir;
431 ihold(new_dir);
432 data->old_dentry = dget(old_dentry);
433 data->new_dentry = dget(new_dentry);
434 nfs_fattr_init(&data->old_fattr);
435 nfs_fattr_init(&data->new_fattr);
437 /* set up nfs_renameargs */
438 data->args.old_dir = NFS_FH(old_dir);
439 data->args.old_name = &old_dentry->d_name;
440 data->args.new_dir = NFS_FH(new_dir);
441 data->args.new_name = &new_dentry->d_name;
443 /* set up nfs_renameres */
444 data->res.old_fattr = &data->old_fattr;
445 data->res.new_fattr = &data->new_fattr;
447 nfs_sb_active(old_dir->i_sb);
449 NFS_PROTO(data->old_dir)->rename_setup(&msg, old_dir);
451 return rpc_run_task(&task_setup_data);
455 * nfs_sillyrename - Perform a silly-rename of a dentry
456 * @dir: inode of directory that contains dentry
457 * @dentry: dentry to be sillyrenamed
459 * NFSv2/3 is stateless and the server doesn't know when the client is
460 * holding a file open. To prevent application problems when a file is
461 * unlinked while it's still open, the client performs a "silly-rename".
462 * That is, it renames the file to a hidden file in the same directory,
463 * and only performs the unlink once the last reference to it is put.
465 * The final cleanup is done during dentry_iput.
467 * (Note: NFSv4 is stateful, and has opens, so in theory an NFSv4 server
468 * could take responsibility for keeping open files referenced. The server
469 * would also need to ensure that opened-but-deleted files were kept over
470 * reboots. However, we may not assume a server does so. (RFC 5661
471 * does provide an OPEN4_RESULT_PRESERVE_UNLINKED flag that a server can
472 * use to advertise that it does this; some day we may take advantage of
473 * it.))
476 nfs_sillyrename(struct inode *dir, struct dentry *dentry)
478 static unsigned int sillycounter;
479 const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2;
480 const int countersize = sizeof(sillycounter)*2;
481 const int slen = sizeof(".nfs")+fileidsize+countersize-1;
482 char silly[slen+1];
483 struct dentry *sdentry;
484 struct rpc_task *task;
485 int error = -EIO;
487 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
488 dentry->d_parent->d_name.name, dentry->d_name.name,
489 dentry->d_count);
490 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
493 * We don't allow a dentry to be silly-renamed twice.
495 error = -EBUSY;
496 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
497 goto out;
499 sprintf(silly, ".nfs%*.*Lx",
500 fileidsize, fileidsize,
501 (unsigned long long)NFS_FILEID(dentry->d_inode));
503 /* Return delegation in anticipation of the rename */
504 NFS_PROTO(dentry->d_inode)->return_delegation(dentry->d_inode);
506 sdentry = NULL;
507 do {
508 char *suffix = silly + slen - countersize;
510 dput(sdentry);
511 sillycounter++;
512 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
514 dfprintk(VFS, "NFS: trying to rename %s to %s\n",
515 dentry->d_name.name, silly);
517 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
519 * N.B. Better to return EBUSY here ... it could be
520 * dangerous to delete the file while it's in use.
522 if (IS_ERR(sdentry))
523 goto out;
524 } while (sdentry->d_inode != NULL); /* need negative lookup */
526 /* queue unlink first. Can't do this from rpc_release as it
527 * has to allocate memory
529 error = nfs_async_unlink(dir, dentry);
530 if (error)
531 goto out_dput;
533 /* populate unlinkdata with the right dname */
534 error = nfs_copy_dname(sdentry,
535 (struct nfs_unlinkdata *)dentry->d_fsdata);
536 if (error) {
537 nfs_cancel_async_unlink(dentry);
538 goto out_dput;
541 /* run the rename task, undo unlink if it fails */
542 task = nfs_async_rename(dir, dir, dentry, sdentry);
543 if (IS_ERR(task)) {
544 error = -EBUSY;
545 nfs_cancel_async_unlink(dentry);
546 goto out_dput;
549 /* wait for the RPC task to complete, unless a SIGKILL intervenes */
550 error = rpc_wait_for_completion_task(task);
551 if (error == 0)
552 error = task->tk_status;
553 rpc_put_task(task);
554 out_dput:
555 dput(sdentry);
556 out:
557 return error;