blob: 0e28189c2151d42e55ddc76abb5abe7d3948b06f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/unlink.c
3 *
4 * nfs sillydelete handling
5 *
6 * NOTE: we rely on holding the BKL for list manipulation protection.
7 */
8
9#include <linux/slab.h>
10#include <linux/string.h>
11#include <linux/dcache.h>
12#include <linux/sunrpc/sched.h>
13#include <linux/sunrpc/clnt.h>
14#include <linux/nfs_fs.h>
15
16
17struct nfs_unlinkdata {
18 struct nfs_unlinkdata *next;
19 struct dentry *dir, *dentry;
20 struct qstr name;
21 struct rpc_task task;
22 struct rpc_cred *cred;
23 unsigned int count;
24};
25
26static struct nfs_unlinkdata *nfs_deletes;
27static RPC_WAITQ(nfs_delete_queue, "nfs_delete_queue");
28
29/**
30 * nfs_detach_unlinkdata - Remove asynchronous unlink from global list
31 * @data: pointer to descriptor
32 */
33static inline void
34nfs_detach_unlinkdata(struct nfs_unlinkdata *data)
35{
36 struct nfs_unlinkdata **q;
37
38 for (q = &nfs_deletes; *q != NULL; q = &((*q)->next)) {
39 if (*q == data) {
40 *q = data->next;
41 break;
42 }
43 }
44}
45
46/**
47 * nfs_put_unlinkdata - release data from a sillydelete operation.
48 * @data: pointer to unlink structure.
49 */
50static void
51nfs_put_unlinkdata(struct nfs_unlinkdata *data)
52{
53 if (--data->count == 0) {
54 nfs_detach_unlinkdata(data);
Jesper Juhlf99d49a2005-11-07 01:01:34 -080055 kfree(data->name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 kfree(data);
57 }
58}
59
60#define NAME_ALLOC_LEN(len) ((len+16) & ~15)
61/**
62 * nfs_copy_dname - copy dentry name to data structure
63 * @dentry: pointer to dentry
64 * @data: nfs_unlinkdata
65 */
66static inline void
67nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
68{
69 char *str;
70 int len = dentry->d_name.len;
71
72 str = kmalloc(NAME_ALLOC_LEN(len), GFP_KERNEL);
73 if (!str)
74 return;
75 memcpy(str, dentry->d_name.name, len);
76 if (!data->name.len) {
77 data->name.len = len;
78 data->name.name = str;
79 } else
80 kfree(str);
81}
82
83/**
84 * nfs_async_unlink_init - Initialize the RPC info
85 * @task: rpc_task of the sillydelete
86 *
87 * We delay initializing RPC info until after the call to dentry_iput()
88 * in order to minimize races against rename().
89 */
Trond Myklebust4ce70ad2006-01-03 09:55:05 +010090static void nfs_async_unlink_init(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Trond Myklebust4ce70ad2006-01-03 09:55:05 +010092 struct nfs_unlinkdata *data = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 struct dentry *dir = data->dir;
94 struct rpc_message msg = {
95 .rpc_cred = data->cred,
96 };
97 int status = -ENOENT;
98
99 if (!data->name.len)
100 goto out_err;
101
102 status = NFS_PROTO(dir->d_inode)->unlink_setup(&msg, dir, &data->name);
103 if (status < 0)
104 goto out_err;
105 nfs_begin_data_update(dir->d_inode);
106 rpc_call_setup(task, &msg, 0);
107 return;
108 out_err:
109 rpc_exit(task, status);
110}
111
112/**
113 * nfs_async_unlink_done - Sillydelete post-processing
114 * @task: rpc_task of the sillydelete
115 *
116 * Do the directory attribute update.
117 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100118static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100120 struct nfs_unlinkdata *data = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 struct dentry *dir = data->dir;
122 struct inode *dir_i;
123
124 if (!dir)
125 return;
126 dir_i = dir->d_inode;
127 nfs_end_data_update(dir_i);
128 if (NFS_PROTO(dir_i)->unlink_done(dir, task))
129 return;
130 put_rpccred(data->cred);
131 data->cred = NULL;
132 dput(dir);
133}
134
135/**
136 * nfs_async_unlink_release - Release the sillydelete data.
137 * @task: rpc_task of the sillydelete
138 *
139 * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
140 * rpc_task would be freed too.
141 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100142static void nfs_async_unlink_release(void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100144 struct nfs_unlinkdata *data = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 nfs_put_unlinkdata(data);
146}
147
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100148static const struct rpc_call_ops nfs_unlink_ops = {
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100149 .rpc_call_prepare = nfs_async_unlink_init,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100150 .rpc_call_done = nfs_async_unlink_done,
151 .rpc_release = nfs_async_unlink_release,
152};
153
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154/**
155 * nfs_async_unlink - asynchronous unlinking of a file
156 * @dentry: dentry to unlink
157 */
158int
159nfs_async_unlink(struct dentry *dentry)
160{
161 struct dentry *dir = dentry->d_parent;
162 struct nfs_unlinkdata *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 struct rpc_clnt *clnt = NFS_CLIENT(dir->d_inode);
164 int status = -ENOMEM;
165
Eric Sesterhennbd647542006-03-20 13:44:10 -0500166 data = kzalloc(sizeof(*data), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 if (!data)
168 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 data->cred = rpcauth_lookupcred(clnt->cl_auth, 0);
171 if (IS_ERR(data->cred)) {
172 status = PTR_ERR(data->cred);
173 goto out_free;
174 }
175 data->dir = dget(dir);
176 data->dentry = dentry;
177
178 data->next = nfs_deletes;
179 nfs_deletes = data;
180 data->count = 1;
181
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100182 rpc_init_task(&data->task, clnt, RPC_TASK_ASYNC, &nfs_unlink_ops, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 spin_lock(&dentry->d_lock);
185 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
186 spin_unlock(&dentry->d_lock);
187
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100188 rpc_sleep_on(&nfs_delete_queue, &data->task, NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 status = 0;
190 out:
191 return status;
192out_free:
193 kfree(data);
194 return status;
195}
196
197/**
198 * nfs_complete_unlink - Initialize completion of the sillydelete
199 * @dentry: dentry to delete
200 *
201 * Since we're most likely to be called by dentry_iput(), we
202 * only use the dentry to find the sillydelete. We then copy the name
203 * into the qstr.
204 */
205void
206nfs_complete_unlink(struct dentry *dentry)
207{
208 struct nfs_unlinkdata *data;
209
210 for(data = nfs_deletes; data != NULL; data = data->next) {
211 if (dentry == data->dentry)
212 break;
213 }
214 if (!data)
215 return;
216 data->count++;
217 nfs_copy_dname(dentry, data);
218 spin_lock(&dentry->d_lock);
219 dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
220 spin_unlock(&dentry->d_lock);
221 rpc_wake_up_task(&data->task);
222 nfs_put_unlinkdata(data);
223}