Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/unlink.c | |
3 | * | |
4 | * nfs sillydelete handling | |
5 | * | |
1da177e4 LT |
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> | |
b35e7041 LT |
14 | #include <linux/sched.h> |
15 | #include <linux/wait.h> | |
1da177e4 | 16 | |
ef818a28 SD |
17 | #include "internal.h" |
18 | ||
1da177e4 | 19 | struct nfs_unlinkdata { |
565277f6 | 20 | struct hlist_node list; |
e4eff1a6 TM |
21 | struct nfs_removeargs args; |
22 | struct nfs_removeres res; | |
23 | struct inode *dir; | |
1da177e4 | 24 | struct rpc_cred *cred; |
1da177e4 LT |
25 | }; |
26 | ||
1da177e4 | 27 | /** |
e4eff1a6 | 28 | * nfs_free_unlinkdata - release data from a sillydelete operation. |
1da177e4 LT |
29 | * @data: pointer to unlink structure. |
30 | */ | |
31 | static void | |
e4eff1a6 | 32 | nfs_free_unlinkdata(struct nfs_unlinkdata *data) |
1da177e4 | 33 | { |
e4eff1a6 TM |
34 | iput(data->dir); |
35 | put_rpccred(data->cred); | |
36 | kfree(data->args.name.name); | |
37 | kfree(data); | |
1da177e4 LT |
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 | */ | |
e4eff1a6 | 46 | static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data) |
1da177e4 LT |
47 | { |
48 | char *str; | |
49 | int len = dentry->d_name.len; | |
50 | ||
e4eff1a6 | 51 | str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL); |
1da177e4 | 52 | if (!str) |
e4eff1a6 TM |
53 | return -ENOMEM; |
54 | data->args.name.len = len; | |
55 | data->args.name.name = str; | |
56 | return 0; | |
1da177e4 LT |
57 | } |
58 | ||
565277f6 TM |
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 | ||
1da177e4 LT |
73 | /** |
74 | * nfs_async_unlink_init - Initialize the RPC info | |
e4eff1a6 | 75 | * task: rpc_task of the sillydelete |
1da177e4 | 76 | */ |
4ce70ada | 77 | static void nfs_async_unlink_init(struct rpc_task *task, void *calldata) |
1da177e4 | 78 | { |
e4eff1a6 TM |
79 | struct nfs_unlinkdata *data = calldata; |
80 | struct inode *dir = data->dir; | |
81 | struct rpc_message msg = { | |
82 | .rpc_argp = &data->args, | |
83 | .rpc_resp = &data->res, | |
84 | .rpc_cred = data->cred, | |
1da177e4 | 85 | }; |
1da177e4 | 86 | |
e4eff1a6 | 87 | NFS_PROTO(dir)->unlink_setup(&msg, dir); |
1da177e4 | 88 | rpc_call_setup(task, &msg, 0); |
1da177e4 LT |
89 | } |
90 | ||
91 | /** | |
92 | * nfs_async_unlink_done - Sillydelete post-processing | |
93 | * @task: rpc_task of the sillydelete | |
94 | * | |
95 | * Do the directory attribute update. | |
96 | */ | |
963d8fe5 | 97 | static void nfs_async_unlink_done(struct rpc_task *task, void *calldata) |
1da177e4 | 98 | { |
e4eff1a6 TM |
99 | struct nfs_unlinkdata *data = calldata; |
100 | struct inode *dir = data->dir; | |
101 | ||
102 | if (!NFS_PROTO(dir)->unlink_done(task, dir)) | |
103 | rpc_restart_call(task); | |
1da177e4 LT |
104 | } |
105 | ||
106 | /** | |
107 | * nfs_async_unlink_release - Release the sillydelete data. | |
108 | * @task: rpc_task of the sillydelete | |
109 | * | |
110 | * We need to call nfs_put_unlinkdata as a 'tk_release' task since the | |
111 | * rpc_task would be freed too. | |
112 | */ | |
963d8fe5 | 113 | static void nfs_async_unlink_release(void *calldata) |
1da177e4 | 114 | { |
963d8fe5 | 115 | struct nfs_unlinkdata *data = calldata; |
565277f6 TM |
116 | |
117 | nfs_dec_sillycount(data->dir); | |
ef818a28 | 118 | nfs_sb_deactive(NFS_SERVER(data->dir)); |
e4eff1a6 | 119 | nfs_free_unlinkdata(data); |
1da177e4 LT |
120 | } |
121 | ||
963d8fe5 | 122 | static const struct rpc_call_ops nfs_unlink_ops = { |
4ce70ada | 123 | .rpc_call_prepare = nfs_async_unlink_init, |
963d8fe5 TM |
124 | .rpc_call_done = nfs_async_unlink_done, |
125 | .rpc_release = nfs_async_unlink_release, | |
126 | }; | |
127 | ||
565277f6 | 128 | static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data) |
e4eff1a6 TM |
129 | { |
130 | struct rpc_task *task; | |
565277f6 TM |
131 | struct dentry *alias; |
132 | ||
133 | alias = d_lookup(parent, &data->args.name); | |
134 | if (alias != NULL) { | |
135 | int ret = 0; | |
609005c3 | 136 | |
565277f6 TM |
137 | /* |
138 | * Hey, we raced with lookup... See if we need to transfer | |
139 | * the sillyrename information to the aliased dentry. | |
140 | */ | |
141 | nfs_free_dname(data); | |
142 | spin_lock(&alias->d_lock); | |
609005c3 TM |
143 | if (alias->d_inode != NULL && |
144 | !(alias->d_flags & DCACHE_NFSFS_RENAMED)) { | |
565277f6 | 145 | alias->d_fsdata = data; |
fccca7fc | 146 | alias->d_flags |= DCACHE_NFSFS_RENAMED; |
565277f6 TM |
147 | ret = 1; |
148 | } | |
149 | spin_unlock(&alias->d_lock); | |
150 | nfs_dec_sillycount(dir); | |
151 | dput(alias); | |
152 | return ret; | |
153 | } | |
154 | data->dir = igrab(dir); | |
155 | if (!data->dir) { | |
156 | nfs_dec_sillycount(dir); | |
157 | return 0; | |
158 | } | |
ef818a28 | 159 | nfs_sb_active(NFS_SERVER(dir)); |
565277f6 TM |
160 | data->args.fh = NFS_FH(dir); |
161 | nfs_fattr_init(&data->res.dir_attr); | |
162 | ||
163 | task = rpc_run_task(NFS_CLIENT(dir), RPC_TASK_ASYNC, &nfs_unlink_ops, data); | |
164 | if (!IS_ERR(task)) | |
165 | rpc_put_task(task); | |
166 | return 1; | |
167 | } | |
168 | ||
169 | static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data) | |
170 | { | |
e4eff1a6 TM |
171 | struct dentry *parent; |
172 | struct inode *dir; | |
565277f6 | 173 | int ret = 0; |
e4eff1a6 | 174 | |
e4eff1a6 TM |
175 | |
176 | parent = dget_parent(dentry); | |
177 | if (parent == NULL) | |
178 | goto out_free; | |
565277f6 | 179 | dir = parent->d_inode; |
55b70a03 | 180 | if (nfs_copy_dname(dentry, data) != 0) |
565277f6 TM |
181 | goto out_dput; |
182 | /* Non-exclusive lock protects against concurrent lookup() calls */ | |
183 | spin_lock(&dir->i_lock); | |
184 | if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) { | |
185 | /* Deferred delete */ | |
186 | hlist_add_head(&data->list, &NFS_I(dir)->silly_list); | |
187 | spin_unlock(&dir->i_lock); | |
188 | ret = 1; | |
189 | goto out_dput; | |
190 | } | |
191 | spin_unlock(&dir->i_lock); | |
192 | ret = nfs_do_call_unlink(parent, dir, data); | |
193 | out_dput: | |
e4eff1a6 | 194 | dput(parent); |
565277f6 TM |
195 | out_free: |
196 | return ret; | |
197 | } | |
e4eff1a6 | 198 | |
565277f6 TM |
199 | void nfs_block_sillyrename(struct dentry *dentry) |
200 | { | |
201 | struct nfs_inode *nfsi = NFS_I(dentry->d_inode); | |
e4eff1a6 | 202 | |
565277f6 TM |
203 | wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1); |
204 | } | |
205 | ||
206 | void nfs_unblock_sillyrename(struct dentry *dentry) | |
207 | { | |
208 | struct inode *dir = dentry->d_inode; | |
209 | struct nfs_inode *nfsi = NFS_I(dir); | |
210 | struct nfs_unlinkdata *data; | |
211 | ||
212 | atomic_inc(&nfsi->silly_count); | |
213 | spin_lock(&dir->i_lock); | |
214 | while (!hlist_empty(&nfsi->silly_list)) { | |
215 | if (!atomic_inc_not_zero(&nfsi->silly_count)) | |
216 | break; | |
217 | data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list); | |
218 | hlist_del(&data->list); | |
219 | spin_unlock(&dir->i_lock); | |
220 | if (nfs_do_call_unlink(dentry, dir, data) == 0) | |
221 | nfs_free_unlinkdata(data); | |
222 | spin_lock(&dir->i_lock); | |
223 | } | |
224 | spin_unlock(&dir->i_lock); | |
e4eff1a6 TM |
225 | } |
226 | ||
1da177e4 LT |
227 | /** |
228 | * nfs_async_unlink - asynchronous unlinking of a file | |
e4eff1a6 | 229 | * @dir: parent directory of dentry |
1da177e4 LT |
230 | * @dentry: dentry to unlink |
231 | */ | |
232 | int | |
e4eff1a6 | 233 | nfs_async_unlink(struct inode *dir, struct dentry *dentry) |
1da177e4 | 234 | { |
e4eff1a6 TM |
235 | struct nfs_unlinkdata *data; |
236 | int status = -ENOMEM; | |
1da177e4 | 237 | |
bd647545 | 238 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
e4eff1a6 | 239 | if (data == NULL) |
1da177e4 | 240 | goto out; |
1da177e4 | 241 | |
e4eff1a6 | 242 | data->cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0); |
1da177e4 LT |
243 | if (IS_ERR(data->cred)) { |
244 | status = PTR_ERR(data->cred); | |
245 | goto out_free; | |
246 | } | |
1da177e4 | 247 | |
e4eff1a6 | 248 | status = -EBUSY; |
1da177e4 | 249 | spin_lock(&dentry->d_lock); |
e4eff1a6 TM |
250 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) |
251 | goto out_unlock; | |
1da177e4 | 252 | dentry->d_flags |= DCACHE_NFSFS_RENAMED; |
e4eff1a6 | 253 | dentry->d_fsdata = data; |
1da177e4 | 254 | spin_unlock(&dentry->d_lock); |
e4eff1a6 TM |
255 | return 0; |
256 | out_unlock: | |
257 | spin_unlock(&dentry->d_lock); | |
258 | put_rpccred(data->cred); | |
1da177e4 LT |
259 | out_free: |
260 | kfree(data); | |
e4eff1a6 | 261 | out: |
1da177e4 LT |
262 | return status; |
263 | } | |
264 | ||
265 | /** | |
266 | * nfs_complete_unlink - Initialize completion of the sillydelete | |
267 | * @dentry: dentry to delete | |
e4eff1a6 | 268 | * @inode: inode |
1da177e4 LT |
269 | * |
270 | * Since we're most likely to be called by dentry_iput(), we | |
271 | * only use the dentry to find the sillydelete. We then copy the name | |
272 | * into the qstr. | |
273 | */ | |
274 | void | |
e4eff1a6 | 275 | nfs_complete_unlink(struct dentry *dentry, struct inode *inode) |
1da177e4 | 276 | { |
e4eff1a6 | 277 | struct nfs_unlinkdata *data = NULL; |
1da177e4 | 278 | |
1da177e4 | 279 | spin_lock(&dentry->d_lock); |
e4eff1a6 TM |
280 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
281 | dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; | |
282 | data = dentry->d_fsdata; | |
283 | } | |
1da177e4 | 284 | spin_unlock(&dentry->d_lock); |
e4eff1a6 TM |
285 | |
286 | if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data))) | |
287 | nfs_free_unlinkdata(data); | |
1da177e4 | 288 | } |