blob: de54129336c6d095984fd34c548491a2916e902b [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 iput(data->dir);
34 put_rpccred(data->cred);
35 kfree(data->args.name.name);
36 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037}
38
39#define NAME_ALLOC_LEN(len) ((len+16) & ~15)
40/**
41 * nfs_copy_dname - copy dentry name to data structure
42 * @dentry: pointer to dentry
43 * @data: nfs_unlinkdata
44 */
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040045static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046{
47 char *str;
48 int len = dentry->d_name.len;
49
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040050 str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 if (!str)
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040052 return -ENOMEM;
53 data->args.name.len = len;
54 data->args.name.name = str;
55 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056}
57
Trond Myklebust565277f2007-10-15 18:17:53 -040058static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070072/**
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 * nfs_async_unlink_done - Sillydelete post-processing
74 * @task: rpc_task of the sillydelete
75 *
76 * Do the directory attribute update.
77 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +010078static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040080 struct nfs_unlinkdata *data = calldata;
81 struct inode *dir = data->dir;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Trond Myklebust70ded202013-08-21 12:08:45 -040083 trace_nfs_sillyrename_unlink(data, task->tk_status);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -040084 if (!NFS_PROTO(dir)->unlink_done(task, dir))
Trond Myklebustd00c5d42011-10-19 12:17:29 -070085 rpc_restart_call_prepare(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086}
87
88/**
89 * nfs_async_unlink_release - Release the sillydelete data.
90 * @task: rpc_task of the sillydelete
91 *
92 * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
93 * rpc_task would be freed too.
94 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +010095static void nfs_async_unlink_release(void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
Trond Myklebust963d8fe2006-01-03 09:55:04 +010097 struct nfs_unlinkdata *data = calldata;
Trond Myklebust744d18d2008-07-27 18:03:19 -040098 struct super_block *sb = data->dir->i_sb;
Trond Myklebust565277f2007-10-15 18:17:53 -040099
100 nfs_dec_sillycount(data->dir);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400101 nfs_free_unlinkdata(data);
Trond Myklebust322b2b92013-01-11 16:39:51 -0500102 nfs_sb_deactive(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
Trond Myklebust17280172012-03-11 13:11:00 -0400105static void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
Andy Adamson472cfbd2009-04-01 09:22:24 -0400106{
107 struct nfs_unlinkdata *data = calldata;
Bryan Schumaker34e137c2012-03-19 14:54:41 -0400108 NFS_PROTO(data->dir)->unlink_rpc_prepare(task, data);
Andy Adamson472cfbd2009-04-01 09:22:24 -0400109}
Andy Adamson472cfbd2009-04-01 09:22:24 -0400110
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100111static const struct rpc_call_ops nfs_unlink_ops = {
112 .rpc_call_done = nfs_async_unlink_done,
113 .rpc_release = nfs_async_unlink_release,
Andy Adamson472cfbd2009-04-01 09:22:24 -0400114 .rpc_call_prepare = nfs_unlink_prepare,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100115};
116
Trond Myklebust565277f2007-10-15 18:17:53 -0400117static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400118{
Trond Myklebust5138fde2007-07-14 15:40:01 -0400119 struct rpc_message msg = {
120 .rpc_argp = &data->args,
121 .rpc_resp = &data->res,
122 .rpc_cred = data->cred,
123 };
Trond Myklebustc970aa82007-07-14 15:39:59 -0400124 struct rpc_task_setup task_setup_data = {
Trond Myklebust5138fde2007-07-14 15:40:01 -0400125 .rpc_message = &msg,
Trond Myklebustc970aa82007-07-14 15:39:59 -0400126 .callback_ops = &nfs_unlink_ops,
127 .callback_data = data,
Trond Myklebust1daef0a2008-07-27 18:19:01 -0400128 .workqueue = nfsiod_workqueue,
Trond Myklebustc970aa82007-07-14 15:39:59 -0400129 .flags = RPC_TASK_ASYNC,
130 };
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400131 struct rpc_task *task;
Trond Myklebust565277f2007-10-15 18:17:53 -0400132 struct dentry *alias;
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400133
Trond Myklebust565277f2007-10-15 18:17:53 -0400134 alias = d_lookup(parent, &data->args.name);
135 if (alias != NULL) {
Jeff Layton73ca1002011-07-18 11:26:30 -0400136 int ret;
Al Virob1942c52011-03-16 05:44:14 -0400137 void *devname_garbage = NULL;
Trond Myklebust609005c32008-01-28 19:42:59 -0500138
Trond Myklebust565277f2007-10-15 18:17:53 -0400139 /*
140 * Hey, we raced with lookup... See if we need to transfer
141 * the sillyrename information to the aliased dentry.
142 */
143 nfs_free_dname(data);
Jeff Layton73ca1002011-07-18 11:26:30 -0400144 ret = nfs_copy_dname(alias, data);
Trond Myklebust565277f2007-10-15 18:17:53 -0400145 spin_lock(&alias->d_lock);
Jeff Layton73ca1002011-07-18 11:26:30 -0400146 if (ret == 0 && alias->d_inode != NULL &&
Trond Myklebust609005c32008-01-28 19:42:59 -0500147 !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
Al Virob1942c52011-03-16 05:44:14 -0400148 devname_garbage = alias->d_fsdata;
Trond Myklebust565277f2007-10-15 18:17:53 -0400149 alias->d_fsdata = data;
Trond Myklebustfccca7f2008-01-26 17:37:47 -0500150 alias->d_flags |= DCACHE_NFSFS_RENAMED;
Trond Myklebust565277f2007-10-15 18:17:53 -0400151 ret = 1;
Jeff Layton73ca1002011-07-18 11:26:30 -0400152 } else
153 ret = 0;
Trond Myklebust565277f2007-10-15 18:17:53 -0400154 spin_unlock(&alias->d_lock);
155 nfs_dec_sillycount(dir);
156 dput(alias);
Al Virob1942c52011-03-16 05:44:14 -0400157 /*
158 * If we'd displaced old cached devname, free it. At that
159 * point dentry is definitely not a root, so we won't need
160 * that anymore.
161 */
Jeff Layton73ca1002011-07-18 11:26:30 -0400162 kfree(devname_garbage);
Trond Myklebust565277f2007-10-15 18:17:53 -0400163 return ret;
164 }
165 data->dir = igrab(dir);
166 if (!data->dir) {
167 nfs_dec_sillycount(dir);
168 return 0;
169 }
Trond Myklebust1daef0a2008-07-27 18:19:01 -0400170 nfs_sb_active(dir->i_sb);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400171 data->args.fh = NFS_FH(dir);
Trond Myklebustd3468902010-04-16 16:22:50 -0400172 nfs_fattr_init(data->res.dir_attr);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400173
Trond Myklebust5138fde2007-07-14 15:40:01 -0400174 NFS_PROTO(dir)->unlink_setup(&msg, dir);
Trond Myklebustc970aa82007-07-14 15:39:59 -0400175
Trond Myklebust5138fde2007-07-14 15:40:01 -0400176 task_setup_data.rpc_client = NFS_CLIENT(dir);
Trond Myklebustc970aa82007-07-14 15:39:59 -0400177 task = rpc_run_task(&task_setup_data);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400178 if (!IS_ERR(task))
Trond Myklebustbf294b42011-02-21 11:05:41 -0800179 rpc_put_task_async(task);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400180 return 1;
Trond Myklebust565277f2007-10-15 18:17:53 -0400181}
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 = parent->d_inode;
Trond Myklebust565277f2007-10-15 18:17:53 -0400194 /* Non-exclusive lock protects against concurrent lookup() calls */
195 spin_lock(&dir->i_lock);
196 if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
197 /* Deferred delete */
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);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400207out_free:
Trond Myklebust565277f2007-10-15 18:17:53 -0400208 return ret;
209}
210
Trond Myklebustba6c0592013-08-30 12:24:25 -0400211void nfs_wait_on_sillyrename(struct dentry *dentry)
212{
213 struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
214
215 wait_event(nfsi->waitqueue, atomic_read(&nfsi->silly_count) <= 1);
216}
217
Trond Myklebust565277f2007-10-15 18:17:53 -0400218void nfs_block_sillyrename(struct dentry *dentry)
219{
220 struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
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 = dentry->d_inode;
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);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400244}
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246/**
247 * nfs_async_unlink - asynchronous unlinking of a file
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400248 * @dir: parent directory of dentry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 * @dentry: dentry to unlink
250 */
Jeff Layton779c5172010-09-17 17:31:30 -0400251static int
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400252nfs_async_unlink(struct inode *dir, struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400254 struct nfs_unlinkdata *data;
255 int status = -ENOMEM;
Al Virob1942c52011-03-16 05:44:14 -0400256 void *devname_garbage = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Eric Sesterhennbd647542006-03-20 13:44:10 -0500258 data = kzalloc(sizeof(*data), GFP_KERNEL);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400259 if (data == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
Trond Myklebust98a8e322008-03-12 12:25:28 -0400262 data->cred = rpc_lookup_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 if (IS_ERR(data->cred)) {
264 status = PTR_ERR(data->cred);
265 goto out_free;
266 }
Trond Myklebustd3468902010-04-16 16:22:50 -0400267 data->res.dir_attr = &data->dir_attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400269 status = -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 spin_lock(&dentry->d_lock);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400271 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
272 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
Al Virob1942c52011-03-16 05:44:14 -0400274 devname_garbage = dentry->d_fsdata;
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400275 dentry->d_fsdata = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 spin_unlock(&dentry->d_lock);
Al Virob1942c52011-03-16 05:44:14 -0400277 /*
278 * If we'd displaced old cached devname, free it. At that
279 * point dentry is definitely not a root, so we won't need
280 * that anymore.
281 */
Tim Gardner96aa1542013-02-12 13:03:42 -0700282 kfree(devname_garbage);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400283 return 0;
284out_unlock:
285 spin_unlock(&dentry->d_lock);
286 put_rpccred(data->cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287out_free:
288 kfree(data);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400289out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 return status;
291}
292
293/**
294 * nfs_complete_unlink - Initialize completion of the sillydelete
295 * @dentry: dentry to delete
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400296 * @inode: inode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 *
298 * Since we're most likely to be called by dentry_iput(), we
299 * only use the dentry to find the sillydelete. We then copy the name
300 * into the qstr.
301 */
302void
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400303nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304{
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400305 struct nfs_unlinkdata *data = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 spin_lock(&dentry->d_lock);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400308 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
309 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
310 data = dentry->d_fsdata;
Al Virob1942c52011-03-16 05:44:14 -0400311 dentry->d_fsdata = NULL;
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400312 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 spin_unlock(&dentry->d_lock);
Trond Myklebuste4eff1a2007-07-14 15:39:58 -0400314
315 if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
316 nfs_free_unlinkdata(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317}
Jeff Layton779c5172010-09-17 17:31:30 -0400318
Jeff Laytond3d41522010-09-17 17:31:57 -0400319/* Cancel a queued async unlink. Called when a sillyrename run fails. */
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;
Al Virob1942c52011-03-16 05:44:14 -0400328 dentry->d_fsdata = NULL;
Jeff Laytond3d41522010-09-17 17:31:57 -0400329 spin_unlock(&dentry->d_lock);
330 nfs_free_unlinkdata(data);
331 return;
332 }
333 spin_unlock(&dentry->d_lock);
334}
335
Jeff Laytond3d41522010-09-17 17:31:57 -0400336/**
337 * nfs_async_rename_done - Sillyrename post-processing
338 * @task: rpc_task of the sillyrename
339 * @calldata: nfs_renamedata for the sillyrename
340 *
341 * Do the directory attribute updates and the d_move
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;
Jeff Layton73ca1002011-07-18 11:26:30 -0400348 struct dentry *old_dentry = data->old_dentry;
Jeff Laytond3d41522010-09-17 17:31:57 -0400349
Trond Myklebust70ded202013-08-21 12:08:45 -0400350 trace_nfs_sillyrename_rename(old_dir, old_dentry,
351 new_dir, data->new_dentry, task->tk_status);
Jeff Laytond3d41522010-09-17 17:31:57 -0400352 if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700353 rpc_restart_call_prepare(task);
Jeff Laytond3d41522010-09-17 17:31:57 -0400354 return;
355 }
356
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400357 if (data->complete)
358 data->complete(task, data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400359}
360
361/**
362 * nfs_async_rename_release - Release the sillyrename data.
363 * @calldata: the struct nfs_renamedata to be released
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 (data->old_dentry->d_inode)
371 nfs_mark_for_revalidate(data->old_dentry->d_inode);
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
Jeff Laytond3d41522010-09-17 17:31:57 -0400382static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
383{
384 struct nfs_renamedata *data = calldata;
Bryan Schumakerc6bfa1a2012-03-19 14:54:42 -0400385 NFS_PROTO(data->old_dir)->rename_rpc_prepare(task, data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400386}
Jeff Laytond3d41522010-09-17 17:31:57 -0400387
388static const struct rpc_call_ops nfs_rename_ops = {
389 .rpc_call_done = nfs_async_rename_done,
390 .rpc_release = nfs_async_rename_release,
Jeff Laytond3d41522010-09-17 17:31:57 -0400391 .rpc_call_prepare = nfs_rename_prepare,
Jeff Laytond3d41522010-09-17 17:31:57 -0400392};
393
394/**
395 * nfs_async_rename - perform an asynchronous rename operation
396 * @old_dir: directory that currently holds the dentry to be renamed
397 * @new_dir: target directory for the rename
398 * @old_dentry: original dentry to be renamed
399 * @new_dentry: dentry to which the old_dentry should be renamed
400 *
401 * It's expected that valid references to the dentries and inodes are held
402 */
Jeff Layton0e862a42014-03-17 07:06:55 -0400403struct rpc_task *
Jeff Laytond3d41522010-09-17 17:31:57 -0400404nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400405 struct dentry *old_dentry, struct dentry *new_dentry,
406 void (*complete)(struct rpc_task *, struct nfs_renamedata *))
Jeff Laytond3d41522010-09-17 17:31:57 -0400407{
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 };
Jeff Laytond3d41522010-09-17 17:31:57 -0400417
Benny Halevydfb4f3092010-09-24 09:17:01 -0400418 data = kzalloc(sizeof(*data), GFP_KERNEL);
Jeff Laytond3d41522010-09-17 17:31:57 -0400419 if (data == NULL)
420 return ERR_PTR(-ENOMEM);
Trond Myklebust1174dd12010-12-21 10:52:24 -0500421 task_setup_data.callback_data = data;
Jeff Laytond3d41522010-09-17 17:31:57 -0400422
423 data->cred = rpc_lookup_cred();
424 if (IS_ERR(data->cred)) {
Trond Myklebustf7732d62010-09-21 16:52:40 -0400425 struct rpc_task *task = ERR_CAST(data->cred);
Jeff Laytond3d41522010-09-17 17:31:57 -0400426 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 /* set up nfs_renamedata */
435 data->old_dir = old_dir;
Al Viroa4118ee2010-10-27 11:00:08 -0400436 ihold(old_dir);
Jeff Laytond3d41522010-09-17 17:31:57 -0400437 data->new_dir = new_dir;
Al Viroa4118ee2010-10-27 11:00:08 -0400438 ihold(new_dir);
Jeff Laytond3d41522010-09-17 17:31:57 -0400439 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);
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400443 data->complete = complete;
Jeff Laytond3d41522010-09-17 17:31:57 -0400444
445 /* set up nfs_renameargs */
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 /* set up nfs_renameres */
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
Trond Myklebustf7732d62010-09-21 16:52:40 -0400459 return rpc_run_task(&task_setup_data);
Jeff Laytond3d41522010-09-17 17:31:57 -0400460}
461
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400462/*
463 * Perform tasks needed when a sillyrename is done such as cancelling the
464 * queued async unlink if it failed.
465 */
466static void
467nfs_complete_sillyrename(struct rpc_task *task, struct nfs_renamedata *data)
468{
Jeff Laytonf7be7282014-03-17 07:06:58 -0400469 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 * vfs_unlink and the like do not issue this when a file is
478 * sillyrenamed, so do it here.
479 */
480 fsnotify_nameremove(dentry, 0);
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400481}
482
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400483#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
Jeff Layton779c5172010-09-17 17:31:30 -0400491/**
492 * nfs_sillyrename - Perform a silly-rename of a dentry
493 * @dir: inode of directory that contains dentry
494 * @dentry: dentry to be sillyrenamed
495 *
496 * NFSv2/3 is stateless and the server doesn't know when the client is
497 * holding a file open. To prevent application problems when a file is
498 * unlinked while it's still open, the client performs a "silly-rename".
499 * That is, it renames the file to a hidden file in the same directory,
500 * and only performs the unlink once the last reference to it is put.
501 *
502 * The final cleanup is done during dentry_iput.
J. Bruce Fields674e4052011-07-15 19:09:08 -0400503 *
504 * (Note: NFSv4 is stateful, and has opens, so in theory an NFSv4 server
505 * could take responsibility for keeping open files referenced. The server
506 * would also need to ensure that opened-but-deleted files were kept over
507 * reboots. However, we may not assume a server does so. (RFC 5661
508 * does provide an OPEN4_RESULT_PRESERVE_UNLINKED flag that a server can
509 * use to advertise that it does this; some day we may take advantage of
510 * it.))
Jeff Layton779c5172010-09-17 17:31:30 -0400511 */
512int
513nfs_sillyrename(struct inode *dir, struct dentry *dentry)
514{
515 static unsigned int sillycounter;
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400516 unsigned char silly[SILLYNAME_LEN + 1];
517 unsigned long long fileid;
Jeff Layton779c5172010-09-17 17:31:30 -0400518 struct dentry *sdentry;
Jeff Laytond3d41522010-09-17 17:31:57 -0400519 struct rpc_task *task;
Geyslan G. Bem4f5829d2013-10-11 17:15:54 -0300520 int error = -EBUSY;
Jeff Layton779c5172010-09-17 17:31:30 -0400521
Al Viro6de14722013-09-16 10:53:17 -0400522 dfprintk(VFS, "NFS: silly-rename(%pd2, ct=%d)\n",
523 dentry, d_count(dentry));
Jeff Layton779c5172010-09-17 17:31:30 -0400524 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
525
526 /*
527 * We don't allow a dentry to be silly-renamed twice.
528 */
Jeff Layton779c5172010-09-17 17:31:30 -0400529 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
530 goto out;
531
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400532 fileid = NFS_FILEID(dentry->d_inode);
Jeff Layton779c5172010-09-17 17:31:30 -0400533
534 /* Return delegation in anticipation of the rename */
Bryan Schumaker57ec14c2012-06-20 15:53:44 -0400535 NFS_PROTO(dentry->d_inode)->return_delegation(dentry->d_inode);
Jeff Layton779c5172010-09-17 17:31:30 -0400536
537 sdentry = NULL;
538 do {
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400539 int slen;
Jeff Layton779c5172010-09-17 17:31:30 -0400540 dput(sdentry);
541 sillycounter++;
Trond Myklebustc2dd1372013-08-21 19:54:08 -0400542 slen = scnprintf(silly, sizeof(silly),
543 SILLYNAME_PREFIX "%0*llx%0*x",
544 SILLYNAME_FILEID_LEN, fileid,
545 SILLYNAME_COUNTER_LEN, sillycounter);
Jeff Layton779c5172010-09-17 17:31:30 -0400546
Al Viro6de14722013-09-16 10:53:17 -0400547 dfprintk(VFS, "NFS: trying to rename %pd to %s\n",
548 dentry, silly);
Jeff Layton779c5172010-09-17 17:31:30 -0400549
550 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
551 /*
552 * N.B. Better to return EBUSY here ... it could be
553 * dangerous to delete the file while it's in use.
554 */
555 if (IS_ERR(sdentry))
556 goto out;
557 } while (sdentry->d_inode != NULL); /* need negative lookup */
558
Jeff Laytond3d41522010-09-17 17:31:57 -0400559 /* queue unlink first. Can't do this from rpc_release as it
560 * has to allocate memory
561 */
562 error = nfs_async_unlink(dir, dentry);
563 if (error)
564 goto out_dput;
565
Jeff Layton73ca1002011-07-18 11:26:30 -0400566 /* populate unlinkdata with the right dname */
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
Jeff Laytond3d41522010-09-17 17:31:57 -0400574 /* run the rename task, undo unlink if it fails */
Jeff Layton96f9d8c2014-03-17 07:06:54 -0400575 task = nfs_async_rename(dir, dir, dentry, sdentry,
576 nfs_complete_sillyrename);
Jeff Laytond3d41522010-09-17 17:31:57 -0400577 if (IS_ERR(task)) {
578 error = -EBUSY;
579 nfs_cancel_async_unlink(dentry);
580 goto out_dput;
Jeff Layton779c5172010-09-17 17:31:30 -0400581 }
Jeff Laytond3d41522010-09-17 17:31:57 -0400582
583 /* wait for the RPC task to complete, unless a SIGKILL intervenes */
584 error = rpc_wait_for_completion_task(task);
585 if (error == 0)
586 error = task->tk_status;
Trond Myklebust5a7a6132013-02-22 12:53:43 -0500587 switch (error) {
588 case 0:
589 /* The rename succeeded */
590 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
591 d_move(dentry, sdentry);
592 break;
593 case -ERESTARTSYS:
594 /* The result of the rename is unknown. Play it safe by
595 * forcing a new lookup */
596 d_drop(dentry);
597 d_drop(sdentry);
598 }
Jeff Laytond3d41522010-09-17 17:31:57 -0400599 rpc_put_task(task);
600out_dput:
Jeff Layton779c5172010-09-17 17:31:30 -0400601 dput(sdentry);
602out:
603 return error;
604}