NFS/SUNRPC: Convert all users of rpc_call_setup()
[linux-2.6.git] / fs / nfs / unlink.c
1 /*
2  *  linux/fs/nfs/unlink.c
3  *
4  * nfs sillydelete handling
5  *
6  */
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>
14 #include <linux/sched.h>
15 #include <linux/wait.h>
16
17 #include "internal.h"
18
19 struct nfs_unlinkdata {
20         struct hlist_node list;
21         struct nfs_removeargs args;
22         struct nfs_removeres res;
23         struct inode *dir;
24         struct rpc_cred *cred;
25 };
26
27 /**
28  * nfs_free_unlinkdata - release data from a sillydelete operation.
29  * @data: pointer to unlink structure.
30  */
31 static void
32 nfs_free_unlinkdata(struct nfs_unlinkdata *data)
33 {
34         iput(data->dir);
35         put_rpccred(data->cred);
36         kfree(data->args.name.name);
37         kfree(data);
38 }
39
40 #define NAME_ALLOC_LEN(len)     ((len+16) & ~15)
41 /**
42  * nfs_copy_dname - copy dentry name to data structure
43  * @dentry: pointer to dentry
44  * @data: nfs_unlinkdata
45  */
46 static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
47 {
48         char            *str;
49         int             len = dentry->d_name.len;
50
51         str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
52         if (!str)
53                 return -ENOMEM;
54         data->args.name.len = len;
55         data->args.name.name = str;
56         return 0;
57 }
58
59 static void nfs_free_dname(struct nfs_unlinkdata *data)
60 {
61         kfree(data->args.name.name);
62         data->args.name.name = NULL;
63         data->args.name.len = 0;
64 }
65
66 static void nfs_dec_sillycount(struct inode *dir)
67 {
68         struct nfs_inode *nfsi = NFS_I(dir);
69         if (atomic_dec_return(&nfsi->silly_count) == 1)
70                 wake_up(&nfsi->waitqueue);
71 }
72
73 /**
74  * nfs_async_unlink_done - Sillydelete post-processing
75  * @task: rpc_task of the sillydelete
76  *
77  * Do the directory attribute update.
78  */
79 static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
80 {
81         struct nfs_unlinkdata *data = calldata;
82         struct inode *dir = data->dir;
83
84         if (!NFS_PROTO(dir)->unlink_done(task, dir))
85                 rpc_restart_call(task);
86 }
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  */
95 static void nfs_async_unlink_release(void *calldata)
96 {
97         struct nfs_unlinkdata   *data = calldata;
98
99         nfs_dec_sillycount(data->dir);
100         nfs_sb_deactive(NFS_SERVER(data->dir));
101         nfs_free_unlinkdata(data);
102 }
103
104 static const struct rpc_call_ops nfs_unlink_ops = {
105         .rpc_call_done = nfs_async_unlink_done,
106         .rpc_release = nfs_async_unlink_release,
107 };
108
109 static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
110 {
111         struct rpc_message msg = {
112                 .rpc_argp = &data->args,
113                 .rpc_resp = &data->res,
114                 .rpc_cred = data->cred,
115         };
116         struct rpc_task_setup task_setup_data = {
117                 .rpc_message = &msg,
118                 .callback_ops = &nfs_unlink_ops,
119                 .callback_data = data,
120                 .flags = RPC_TASK_ASYNC,
121         };
122         struct rpc_task *task;
123         struct dentry *alias;
124
125         alias = d_lookup(parent, &data->args.name);
126         if (alias != NULL) {
127                 int ret = 0;
128
129                 /*
130                  * Hey, we raced with lookup... See if we need to transfer
131                  * the sillyrename information to the aliased dentry.
132                  */
133                 nfs_free_dname(data);
134                 spin_lock(&alias->d_lock);
135                 if (alias->d_inode != NULL &&
136                     !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
137                         alias->d_fsdata = data;
138                         alias->d_flags |= DCACHE_NFSFS_RENAMED;
139                         ret = 1;
140                 }
141                 spin_unlock(&alias->d_lock);
142                 nfs_dec_sillycount(dir);
143                 dput(alias);
144                 return ret;
145         }
146         data->dir = igrab(dir);
147         if (!data->dir) {
148                 nfs_dec_sillycount(dir);
149                 return 0;
150         }
151         nfs_sb_active(NFS_SERVER(dir));
152         data->args.fh = NFS_FH(dir);
153         nfs_fattr_init(&data->res.dir_attr);
154
155         NFS_PROTO(dir)->unlink_setup(&msg, dir);
156
157         task_setup_data.rpc_client = NFS_CLIENT(dir);
158         task = rpc_run_task(&task_setup_data);
159         if (!IS_ERR(task))
160                 rpc_put_task(task);
161         return 1;
162 }
163
164 static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
165 {
166         struct dentry *parent;
167         struct inode *dir;
168         int ret = 0;
169
170
171         parent = dget_parent(dentry);
172         if (parent == NULL)
173                 goto out_free;
174         dir = parent->d_inode;
175         if (nfs_copy_dname(dentry, data) != 0)
176                 goto out_dput;
177         /* Non-exclusive lock protects against concurrent lookup() calls */
178         spin_lock(&dir->i_lock);
179         if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
180                 /* Deferred delete */
181                 hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
182                 spin_unlock(&dir->i_lock);
183                 ret = 1;
184                 goto out_dput;
185         }
186         spin_unlock(&dir->i_lock);
187         ret = nfs_do_call_unlink(parent, dir, data);
188 out_dput:
189         dput(parent);
190 out_free:
191         return ret;
192 }
193
194 void nfs_block_sillyrename(struct dentry *dentry)
195 {
196         struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
197
198         wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
199 }
200
201 void nfs_unblock_sillyrename(struct dentry *dentry)
202 {
203         struct inode *dir = dentry->d_inode;
204         struct nfs_inode *nfsi = NFS_I(dir);
205         struct nfs_unlinkdata *data;
206
207         atomic_inc(&nfsi->silly_count);
208         spin_lock(&dir->i_lock);
209         while (!hlist_empty(&nfsi->silly_list)) {
210                 if (!atomic_inc_not_zero(&nfsi->silly_count))
211                         break;
212                 data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
213                 hlist_del(&data->list);
214                 spin_unlock(&dir->i_lock);
215                 if (nfs_do_call_unlink(dentry, dir, data) == 0)
216                         nfs_free_unlinkdata(data);
217                 spin_lock(&dir->i_lock);
218         }
219         spin_unlock(&dir->i_lock);
220 }
221
222 /**
223  * nfs_async_unlink - asynchronous unlinking of a file
224  * @dir: parent directory of dentry
225  * @dentry: dentry to unlink
226  */
227 int
228 nfs_async_unlink(struct inode *dir, struct dentry *dentry)
229 {
230         struct nfs_unlinkdata *data;
231         int status = -ENOMEM;
232
233         data = kzalloc(sizeof(*data), GFP_KERNEL);
234         if (data == NULL)
235                 goto out;
236
237         data->cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);
238         if (IS_ERR(data->cred)) {
239                 status = PTR_ERR(data->cred);
240                 goto out_free;
241         }
242
243         status = -EBUSY;
244         spin_lock(&dentry->d_lock);
245         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
246                 goto out_unlock;
247         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
248         dentry->d_fsdata = data;
249         spin_unlock(&dentry->d_lock);
250         return 0;
251 out_unlock:
252         spin_unlock(&dentry->d_lock);
253         put_rpccred(data->cred);
254 out_free:
255         kfree(data);
256 out:
257         return status;
258 }
259
260 /**
261  * nfs_complete_unlink - Initialize completion of the sillydelete
262  * @dentry: dentry to delete
263  * @inode: inode
264  *
265  * Since we're most likely to be called by dentry_iput(), we
266  * only use the dentry to find the sillydelete. We then copy the name
267  * into the qstr.
268  */
269 void
270 nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
271 {
272         struct nfs_unlinkdata   *data = NULL;
273
274         spin_lock(&dentry->d_lock);
275         if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
276                 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
277                 data = dentry->d_fsdata;
278         }
279         spin_unlock(&dentry->d_lock);
280
281         if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
282                 nfs_free_unlinkdata(data);
283 }