blob: 1868246f56e6f0602140c29322d9cf7dc2234501 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/unlink.c
3 *
4 * nfs sillydelete handling
5 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 */
7
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>
Linus Torvaldsb35e7042007-10-19 19:59:18 -070014#include <linux/sched.h>
15#include <linux/wait.h>
Jeff Layton779c5172010-09-17 17:31:30 -040016#include <linux/namei.h>
Jeff Laytonf7be7282014-03-17 07:06:58 -040017#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Steve Dicksonef818a22007-11-08 04:05:04 -050019#include "internal.h"
Andy Adamson472cfbd2009-04-01 09:22:24 -040020#include "nfs4_fs.h"
Jeff Layton779c5172010-09-17 17:31:30 -040021#include "iostat.h"
22#include "delegation.h"
Steve Dicksonef818a22007-11-08 04:05:04 -050023
Trond Myklebust70ded202013-08-21 12:08:45 -040024#include "nfstrace.h"
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026/**
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040027 * nfs_free_unlinkdata - release data from a sillydelete operation.
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * @data: pointer to unlink structure.
29 */
30static void
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040031nfs_free_unlinkdata(struct nfs_unlinkdata *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040033 put_rpccred(data->cred);
34 kfree(data->args.name.name);
35 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036}
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038/**
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 * nfs_async_unlink_done - Sillydelete post-processing
40 * @task: rpc_task of the sillydelete
41 *
42 * Do the directory attribute update.
43 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +010044static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040046 struct nfs_unlinkdata *data = calldata;
Al Viro884be172016-04-28 23:56:31 -040047 struct inode *dir = d_inode(data->dentry->d_parent);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
Trond Myklebust70ded202013-08-21 12:08:45 -040049 trace_nfs_sillyrename_unlink(data, task->tk_status);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040050 if (!NFS_PROTO(dir)->unlink_done(task, dir))
Trond Myklebustd00c5d42011-10-19 12:17:29 -070051 rpc_restart_call_prepare(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052}
53
54/**
55 * nfs_async_unlink_release - Release the sillydelete data.
56 * @task: rpc_task of the sillydelete
57 *
58 * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
59 * rpc_task would be freed too.
60 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +010061static void nfs_async_unlink_release(void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
Trond Myklebust963d8fe2006-01-03 09:55:04 +010063 struct nfs_unlinkdata *data = calldata;
Al Viro884be172016-04-28 23:56:31 -040064 struct dentry *dentry = data->dentry;
65 struct super_block *sb = dentry->d_sb;
Trond Myklebust565277f2007-10-15 18:17:53 -040066
Al Viro884be172016-04-28 23:56:31 -040067 up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
68 d_lookup_done(dentry);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040069 nfs_free_unlinkdata(data);
Al Viro884be172016-04-28 23:56:31 -040070 dput(dentry);
Trond Myklebust322b2b92013-01-11 16:39:51 -050071 nfs_sb_deactive(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072}
73
Trond Myklebust17280172012-03-11 13:11:00 -040074static void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
Andy Adamson472cfbd2009-04-01 09:22:24 -040075{
76 struct nfs_unlinkdata *data = calldata;
Al Viro884be172016-04-28 23:56:31 -040077 struct inode *dir = d_inode(data->dentry->d_parent);
78 NFS_PROTO(dir)->unlink_rpc_prepare(task, data);
Andy Adamson472cfbd2009-04-01 09:22:24 -040079}
Andy Adamson472cfbd2009-04-01 09:22:24 -040080
Trond Myklebust963d8fe2006-01-03 09:55:04 +010081static const struct rpc_call_ops nfs_unlink_ops = {
82 .rpc_call_done = nfs_async_unlink_done,
83 .rpc_release = nfs_async_unlink_release,
Andy Adamson472cfbd2009-04-01 09:22:24 -040084 .rpc_call_prepare = nfs_unlink_prepare,
Trond Myklebust963d8fe2006-01-03 09:55:04 +010085};
86
Al Viro884be172016-04-28 23:56:31 -040087static void nfs_do_call_unlink(struct nfs_unlinkdata *data)
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040088{
Trond Myklebust5138fde2007-07-14 15:40:01 -040089 struct rpc_message msg = {
90 .rpc_argp = &data->args,
91 .rpc_resp = &data->res,
92 .rpc_cred = data->cred,
93 };
Trond Myklebustc970aa82007-07-14 15:39:59 -040094 struct rpc_task_setup task_setup_data = {
Trond Myklebust5138fde2007-07-14 15:40:01 -040095 .rpc_message = &msg,
Trond Myklebustc970aa82007-07-14 15:39:59 -040096 .callback_ops = &nfs_unlink_ops,
97 .callback_data = data,
Trond Myklebust1daef0a2008-07-27 18:19:01 -040098 .workqueue = nfsiod_workqueue,
Trond Myklebustc970aa82007-07-14 15:39:59 -040099 .flags = RPC_TASK_ASYNC,
100 };
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400101 struct rpc_task *task;
Al Viro884be172016-04-28 23:56:31 -0400102 struct inode *dir = d_inode(data->dentry->d_parent);
Trond Myklebust1daef0a2008-07-27 18:19:01 -0400103 nfs_sb_active(dir->i_sb);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400104 data->args.fh = NFS_FH(dir);
Trond Myklebustd3468902010-04-16 16:22:50 -0400105 nfs_fattr_init(data->res.dir_attr);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400106
Trond Myklebust5138fde2007-07-14 15:40:01 -0400107 NFS_PROTO(dir)->unlink_setup(&msg, dir);
Trond Myklebustc970aa82007-07-14 15:39:59 -0400108
Trond Myklebust5138fde2007-07-14 15:40:01 -0400109 task_setup_data.rpc_client = NFS_CLIENT(dir);
Trond Myklebustc970aa82007-07-14 15:39:59 -0400110 task = rpc_run_task(&task_setup_data);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400111 if (!IS_ERR(task))
Trond Myklebustbf294b42011-02-21 11:05:41 -0800112 rpc_put_task_async(task);
Trond Myklebust565277f2007-10-15 18:17:53 -0400113}
114
115static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
116{
Al Viro884be172016-04-28 23:56:31 -0400117 struct inode *dir = d_inode(dentry->d_parent);
118 struct dentry *alias;
Trond Myklebust565277f2007-10-15 18:17:53 -0400119
Al Viro884be172016-04-28 23:56:31 -0400120 down_read_non_owner(&NFS_I(dir)->rmdir_sem);
121 alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq);
122 if (IS_ERR(alias)) {
123 up_read_non_owner(&NFS_I(dir)->rmdir_sem);
124 return 0;
Trond Myklebust565277f2007-10-15 18:17:53 -0400125 }
Al Viro884be172016-04-28 23:56:31 -0400126 if (!d_in_lookup(alias)) {
127 int ret;
128 void *devname_garbage = NULL;
Trond Myklebust565277f2007-10-15 18:17:53 -0400129
Al Viro884be172016-04-28 23:56:31 -0400130 /*
131 * Hey, we raced with lookup... See if we need to transfer
132 * the sillyrename information to the aliased dentry.
133 */
134 spin_lock(&alias->d_lock);
135 if (d_really_is_positive(alias) &&
136 !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
137 devname_garbage = alias->d_fsdata;
138 alias->d_fsdata = data;
139 alias->d_flags |= DCACHE_NFSFS_RENAMED;
140 ret = 1;
141 } else
142 ret = 0;
143 spin_unlock(&alias->d_lock);
144 dput(alias);
145 up_read_non_owner(&NFS_I(dir)->rmdir_sem);
146 /*
147 * If we'd displaced old cached devname, free it. At that
148 * point dentry is definitely not a root, so we won't need
149 * that anymore.
150 */
151 kfree(devname_garbage);
152 return ret;
Trond Myklebust565277f2007-10-15 18:17:53 -0400153 }
Al Viro884be172016-04-28 23:56:31 -0400154 data->dentry = alias;
155 nfs_do_call_unlink(data);
156 return 1;
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400157}
158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159/**
160 * nfs_async_unlink - asynchronous unlinking of a file
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400161 * @dir: parent directory of dentry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 * @dentry: dentry to unlink
163 */
Jeff Layton779c5172010-09-17 17:31:30 -0400164static int
Al Viro884be172016-04-28 23:56:31 -0400165nfs_async_unlink(struct dentry *dentry, struct qstr *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400167 struct nfs_unlinkdata *data;
168 int status = -ENOMEM;
Al Virob1942c52011-03-16 05:44:14 -0400169 void *devname_garbage = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Eric Sesterhennbd647542006-03-20 13:44:10 -0500171 data = kzalloc(sizeof(*data), GFP_KERNEL);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400172 if (data == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 goto out;
Al Viro884be172016-04-28 23:56:31 -0400174 data->args.name.name = kstrdup(name->name, GFP_KERNEL);
175 if (!data->args.name.name)
176 goto out_free;
177 data->args.name.len = name->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Trond Myklebust98a8e322008-03-12 12:25:28 -0400179 data->cred = rpc_lookup_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 if (IS_ERR(data->cred)) {
181 status = PTR_ERR(data->cred);
Al Viro884be172016-04-28 23:56:31 -0400182 goto out_free_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 }
Trond Myklebustd3468902010-04-16 16:22:50 -0400184 data->res.dir_attr = &data->dir_attr;
Al Viro884be172016-04-28 23:56:31 -0400185 init_waitqueue_head(&data->wq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400187 status = -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 spin_lock(&dentry->d_lock);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400189 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
190 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
Al Virob1942c52011-03-16 05:44:14 -0400192 devname_garbage = dentry->d_fsdata;
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400193 dentry->d_fsdata = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 spin_unlock(&dentry->d_lock);
Al Virob1942c52011-03-16 05:44:14 -0400195 /*
196 * If we'd displaced old cached devname, free it. At that
197 * point dentry is definitely not a root, so we won't need
198 * that anymore.
199 */
Tim Gardner96aa1542013-02-12 13:03:42 -0700200 kfree(devname_garbage);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400201 return 0;
202out_unlock:
203 spin_unlock(&dentry->d_lock);
204 put_rpccred(data->cred);
Al Viro884be172016-04-28 23:56:31 -0400205out_free_name:
206 kfree(data->args.name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207out_free:
208 kfree(data);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400209out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 return status;
211}
212
213/**
214 * nfs_complete_unlink - Initialize completion of the sillydelete
215 * @dentry: dentry to delete
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400216 * @inode: inode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 *
218 * Since we're most likely to be called by dentry_iput(), we
219 * only use the dentry to find the sillydelete. We then copy the name
220 * into the qstr.
221 */
222void
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400223nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
Al Viro884be172016-04-28 23:56:31 -0400225 struct nfs_unlinkdata *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 spin_lock(&dentry->d_lock);
Al Viro884be172016-04-28 23:56:31 -0400228 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
229 data = dentry->d_fsdata;
230 dentry->d_fsdata = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 spin_unlock(&dentry->d_lock);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400232
Al Viro884be172016-04-28 23:56:31 -0400233 if (NFS_STALE(inode) || !nfs_call_unlink(dentry, data))
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400234 nfs_free_unlinkdata(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235}
Jeff Layton779c5172010-09-17 17:31:30 -0400236
Jeff Laytond3d41522010-09-17 17:31:57 -0400237/* Cancel a queued async unlink. Called when a sillyrename run fails. */
238static void
239nfs_cancel_async_unlink(struct dentry *dentry)
240{
241 spin_lock(&dentry->d_lock);
242 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
243 struct nfs_unlinkdata *data = dentry->d_fsdata;
244
245 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
Al Virob1942c52011-03-16 05:44:14 -0400246 dentry->d_fsdata = NULL;
Jeff Laytond3d41522010-09-17 17:31:57 -0400247 spin_unlock(&dentry->d_lock);
248 nfs_free_unlinkdata(data);
249 return;
250 }
251 spin_unlock(&dentry->d_lock);
252}
253
Jeff Laytond3d41522010-09-17 17:31:57 -0400254/**
255 * nfs_async_rename_done - Sillyrename post-processing
256 * @task: rpc_task of the sillyrename
257 * @calldata: nfs_renamedata for the sillyrename
258 *
259 * Do the directory attribute updates and the d_move
260 */
261static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
262{
263 struct nfs_renamedata *data = calldata;
264 struct inode *old_dir = data->old_dir;
265 struct inode *new_dir = data->new_dir;
Jeff Layton73ca1002011-07-18 11:26:30 -0400266 struct dentry *old_dentry = data->old_dentry;
Jeff Laytond3d41522010-09-17 17:31:57 -0400267
Trond Myklebust70ded202013-08-21 12:08:45 -0400268 trace_nfs_sillyrename_rename(old_dir, old_dentry,
269 new_dir, data->new_dentry, task->tk_status);
Jeff Laytond3d41522010-09-17 17:31:57 -0400270 if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700271 rpc_restart_call_prepare(task);
Jeff Laytond3d41522010-09-17 17:31:57 -0400272 return;
273 }
274
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400275 if (data->complete)
276 data->complete(task, data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400277}
278
279/**
280 * nfs_async_rename_release - Release the sillyrename data.
281 * @calldata: the struct nfs_renamedata to be released
282 */
283static void nfs_async_rename_release(void *calldata)
284{
285 struct nfs_renamedata *data = calldata;
286 struct super_block *sb = data->old_dir->i_sb;
287
David Howells2b0143b2015-03-17 22:25:59 +0000288 if (d_really_is_positive(data->old_dentry))
289 nfs_mark_for_revalidate(d_inode(data->old_dentry));
Jeff Laytond3d41522010-09-17 17:31:57 -0400290
291 dput(data->old_dentry);
292 dput(data->new_dentry);
293 iput(data->old_dir);
294 iput(data->new_dir);
295 nfs_sb_deactive(sb);
296 put_rpccred(data->cred);
297 kfree(data);
298}
299
Jeff Laytond3d41522010-09-17 17:31:57 -0400300static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
301{
302 struct nfs_renamedata *data = calldata;
Bryan Schumakerc6bfa1a2012-03-19 14:54:42 -0400303 NFS_PROTO(data->old_dir)->rename_rpc_prepare(task, data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400304}
Jeff Laytond3d41522010-09-17 17:31:57 -0400305
306static const struct rpc_call_ops nfs_rename_ops = {
307 .rpc_call_done = nfs_async_rename_done,
308 .rpc_release = nfs_async_rename_release,
Jeff Laytond3d41522010-09-17 17:31:57 -0400309 .rpc_call_prepare = nfs_rename_prepare,
Jeff Laytond3d41522010-09-17 17:31:57 -0400310};
311
312/**
313 * nfs_async_rename - perform an asynchronous rename operation
314 * @old_dir: directory that currently holds the dentry to be renamed
315 * @new_dir: target directory for the rename
316 * @old_dentry: original dentry to be renamed
317 * @new_dentry: dentry to which the old_dentry should be renamed
318 *
319 * It's expected that valid references to the dentries and inodes are held
320 */
Jeff Layton0e862a42014-03-17 07:06:55 -0400321struct rpc_task *
Jeff Laytond3d41522010-09-17 17:31:57 -0400322nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400323 struct dentry *old_dentry, struct dentry *new_dentry,
324 void (*complete)(struct rpc_task *, struct nfs_renamedata *))
Jeff Laytond3d41522010-09-17 17:31:57 -0400325{
326 struct nfs_renamedata *data;
327 struct rpc_message msg = { };
328 struct rpc_task_setup task_setup_data = {
329 .rpc_message = &msg,
330 .callback_ops = &nfs_rename_ops,
331 .workqueue = nfsiod_workqueue,
332 .rpc_client = NFS_CLIENT(old_dir),
333 .flags = RPC_TASK_ASYNC,
334 };
Jeff Laytond3d41522010-09-17 17:31:57 -0400335
Benny Halevydfb4f3092010-09-24 09:17:01 -0400336 data = kzalloc(sizeof(*data), GFP_KERNEL);
Jeff Laytond3d41522010-09-17 17:31:57 -0400337 if (data == NULL)
338 return ERR_PTR(-ENOMEM);
Trond Myklebust1174dd12010-12-21 10:52:24 -0500339 task_setup_data.callback_data = data;
Jeff Laytond3d41522010-09-17 17:31:57 -0400340
341 data->cred = rpc_lookup_cred();
342 if (IS_ERR(data->cred)) {
Trond Myklebustf7732d62010-09-21 16:52:40 -0400343 struct rpc_task *task = ERR_CAST(data->cred);
Jeff Laytond3d41522010-09-17 17:31:57 -0400344 kfree(data);
345 return task;
346 }
347
348 msg.rpc_argp = &data->args;
349 msg.rpc_resp = &data->res;
350 msg.rpc_cred = data->cred;
351
352 /* set up nfs_renamedata */
353 data->old_dir = old_dir;
Al Viroa4118ee2010-10-27 11:00:08 -0400354 ihold(old_dir);
Jeff Laytond3d41522010-09-17 17:31:57 -0400355 data->new_dir = new_dir;
Al Viroa4118ee2010-10-27 11:00:08 -0400356 ihold(new_dir);
Jeff Laytond3d41522010-09-17 17:31:57 -0400357 data->old_dentry = dget(old_dentry);
358 data->new_dentry = dget(new_dentry);
359 nfs_fattr_init(&data->old_fattr);
360 nfs_fattr_init(&data->new_fattr);
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400361 data->complete = complete;
Jeff Laytond3d41522010-09-17 17:31:57 -0400362
363 /* set up nfs_renameargs */
364 data->args.old_dir = NFS_FH(old_dir);
365 data->args.old_name = &old_dentry->d_name;
366 data->args.new_dir = NFS_FH(new_dir);
367 data->args.new_name = &new_dentry->d_name;
368
369 /* set up nfs_renameres */
370 data->res.old_fattr = &data->old_fattr;
371 data->res.new_fattr = &data->new_fattr;
372
373 nfs_sb_active(old_dir->i_sb);
374
375 NFS_PROTO(data->old_dir)->rename_setup(&msg, old_dir);
376
Trond Myklebustf7732d62010-09-21 16:52:40 -0400377 return rpc_run_task(&task_setup_data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400378}
379
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400380/*
381 * Perform tasks needed when a sillyrename is done such as cancelling the
382 * queued async unlink if it failed.
383 */
384static void
385nfs_complete_sillyrename(struct rpc_task *task, struct nfs_renamedata *data)
386{
Jeff Laytonf7be7282014-03-17 07:06:58 -0400387 struct dentry *dentry = data->old_dentry;
388
389 if (task->tk_status != 0) {
390 nfs_cancel_async_unlink(dentry);
391 return;
392 }
393
394 /*
395 * vfs_unlink and the like do not issue this when a file is
396 * sillyrenamed, so do it here.
397 */
398 fsnotify_nameremove(dentry, 0);
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400399}
400
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400401#define SILLYNAME_PREFIX ".nfs"
402#define SILLYNAME_PREFIX_LEN ((unsigned)sizeof(SILLYNAME_PREFIX) - 1)
403#define SILLYNAME_FILEID_LEN ((unsigned)sizeof(u64) << 1)
404#define SILLYNAME_COUNTER_LEN ((unsigned)sizeof(unsigned int) << 1)
405#define SILLYNAME_LEN (SILLYNAME_PREFIX_LEN + \
406 SILLYNAME_FILEID_LEN + \
407 SILLYNAME_COUNTER_LEN)
408
Jeff Layton779c5172010-09-17 17:31:30 -0400409/**
410 * nfs_sillyrename - Perform a silly-rename of a dentry
411 * @dir: inode of directory that contains dentry
412 * @dentry: dentry to be sillyrenamed
413 *
414 * NFSv2/3 is stateless and the server doesn't know when the client is
415 * holding a file open. To prevent application problems when a file is
416 * unlinked while it's still open, the client performs a "silly-rename".
417 * That is, it renames the file to a hidden file in the same directory,
418 * and only performs the unlink once the last reference to it is put.
419 *
420 * The final cleanup is done during dentry_iput.
J. Bruce Fields674e4052011-07-15 19:09:08 -0400421 *
422 * (Note: NFSv4 is stateful, and has opens, so in theory an NFSv4 server
423 * could take responsibility for keeping open files referenced. The server
424 * would also need to ensure that opened-but-deleted files were kept over
425 * reboots. However, we may not assume a server does so. (RFC 5661
426 * does provide an OPEN4_RESULT_PRESERVE_UNLINKED flag that a server can
427 * use to advertise that it does this; some day we may take advantage of
428 * it.))
Jeff Layton779c5172010-09-17 17:31:30 -0400429 */
430int
431nfs_sillyrename(struct inode *dir, struct dentry *dentry)
432{
433 static unsigned int sillycounter;
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400434 unsigned char silly[SILLYNAME_LEN + 1];
435 unsigned long long fileid;
Jeff Layton779c5172010-09-17 17:31:30 -0400436 struct dentry *sdentry;
Jeff Laytond3d41522010-09-17 17:31:57 -0400437 struct rpc_task *task;
Geyslan G. Bem4f5829d2013-10-11 17:15:54 -0300438 int error = -EBUSY;
Jeff Layton779c5172010-09-17 17:31:30 -0400439
Al Viro6de14722013-09-16 10:53:17 -0400440 dfprintk(VFS, "NFS: silly-rename(%pd2, ct=%d)\n",
441 dentry, d_count(dentry));
Jeff Layton779c5172010-09-17 17:31:30 -0400442 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
443
444 /*
445 * We don't allow a dentry to be silly-renamed twice.
446 */
Jeff Layton779c5172010-09-17 17:31:30 -0400447 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
448 goto out;
449
David Howells2b0143b2015-03-17 22:25:59 +0000450 fileid = NFS_FILEID(d_inode(dentry));
Jeff Layton779c5172010-09-17 17:31:30 -0400451
452 /* Return delegation in anticipation of the rename */
David Howells2b0143b2015-03-17 22:25:59 +0000453 NFS_PROTO(d_inode(dentry))->return_delegation(d_inode(dentry));
Jeff Layton779c5172010-09-17 17:31:30 -0400454
455 sdentry = NULL;
456 do {
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400457 int slen;
Jeff Layton779c5172010-09-17 17:31:30 -0400458 dput(sdentry);
459 sillycounter++;
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400460 slen = scnprintf(silly, sizeof(silly),
461 SILLYNAME_PREFIX "%0*llx%0*x",
462 SILLYNAME_FILEID_LEN, fileid,
463 SILLYNAME_COUNTER_LEN, sillycounter);
Jeff Layton779c5172010-09-17 17:31:30 -0400464
Al Viro6de14722013-09-16 10:53:17 -0400465 dfprintk(VFS, "NFS: trying to rename %pd to %s\n",
466 dentry, silly);
Jeff Layton779c5172010-09-17 17:31:30 -0400467
468 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
469 /*
470 * N.B. Better to return EBUSY here ... it could be
471 * dangerous to delete the file while it's in use.
472 */
473 if (IS_ERR(sdentry))
474 goto out;
David Howells2b0143b2015-03-17 22:25:59 +0000475 } while (d_inode(sdentry) != NULL); /* need negative lookup */
Jeff Layton779c5172010-09-17 17:31:30 -0400476
Jeff Laytond3d41522010-09-17 17:31:57 -0400477 /* queue unlink first. Can't do this from rpc_release as it
478 * has to allocate memory
479 */
Al Viro884be172016-04-28 23:56:31 -0400480 error = nfs_async_unlink(dentry, &sdentry->d_name);
Jeff Laytond3d41522010-09-17 17:31:57 -0400481 if (error)
482 goto out_dput;
483
484 /* run the rename task, undo unlink if it fails */
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400485 task = nfs_async_rename(dir, dir, dentry, sdentry,
486 nfs_complete_sillyrename);
Jeff Laytond3d41522010-09-17 17:31:57 -0400487 if (IS_ERR(task)) {
488 error = -EBUSY;
489 nfs_cancel_async_unlink(dentry);
490 goto out_dput;
Jeff Layton779c5172010-09-17 17:31:30 -0400491 }
Jeff Laytond3d41522010-09-17 17:31:57 -0400492
493 /* wait for the RPC task to complete, unless a SIGKILL intervenes */
494 error = rpc_wait_for_completion_task(task);
495 if (error == 0)
496 error = task->tk_status;
Trond Myklebust5a7a6132013-02-22 12:53:43 -0500497 switch (error) {
498 case 0:
499 /* The rename succeeded */
500 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
501 d_move(dentry, sdentry);
502 break;
503 case -ERESTARTSYS:
504 /* The result of the rename is unknown. Play it safe by
505 * forcing a new lookup */
506 d_drop(dentry);
507 d_drop(sdentry);
508 }
Jeff Laytond3d41522010-09-17 17:31:57 -0400509 rpc_put_task(task);
510out_dput:
Jeff Layton779c5172010-09-17 17:31:30 -0400511 dput(sdentry);
512out:
513 return error;
514}