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e69e7fe5 EVH |
1 | /* |
2 | * linux/fs/9p/vfs_file.c | |
3 | * | |
4 | * This file contians vfs file ops for 9P2000. | |
5 | * | |
6 | * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> | |
7 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to: | |
21 | * Free Software Foundation | |
22 | * 51 Franklin Street, Fifth Floor | |
23 | * Boston, MA 02111-1301 USA | |
24 | * | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/fs.h> | |
30 | #include <linux/file.h> | |
31 | #include <linux/stat.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/smp_lock.h> | |
34 | #include <linux/inet.h> | |
35 | #include <linux/version.h> | |
36 | #include <linux/list.h> | |
37 | #include <asm/uaccess.h> | |
38 | #include <linux/idr.h> | |
39 | ||
40 | #include "debug.h" | |
41 | #include "v9fs.h" | |
42 | #include "9p.h" | |
43 | #include "v9fs_vfs.h" | |
44 | #include "fid.h" | |
45 | ||
46 | /** | |
47 | * v9fs_file_open - open a file (or directory) | |
48 | * @inode: inode to be opened | |
49 | * @file: file being opened | |
50 | * | |
51 | */ | |
52 | ||
53 | int v9fs_file_open(struct inode *inode, struct file *file) | |
54 | { | |
55 | struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); | |
56 | struct v9fs_fid *v9fid = v9fs_fid_lookup(file->f_dentry, FID_WALK); | |
57 | struct v9fs_fid *v9newfid = NULL; | |
58 | struct v9fs_fcall *fcall = NULL; | |
59 | int open_mode = 0; | |
60 | unsigned int iounit = 0; | |
61 | int newfid = -1; | |
62 | long result = -1; | |
63 | ||
64 | dprintk(DEBUG_VFS, "inode: %p file: %p v9fid= %p\n", inode, file, | |
65 | v9fid); | |
66 | ||
67 | if (!v9fid) { | |
68 | struct dentry *dentry = file->f_dentry; | |
69 | dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n"); | |
70 | ||
71 | /* XXX - some duplication from lookup, generalize later */ | |
72 | /* basically vfs_lookup is too heavy weight */ | |
73 | v9fid = v9fs_fid_lookup(file->f_dentry, FID_OP); | |
74 | if (!v9fid) | |
75 | return -EBADF; | |
76 | ||
77 | v9fid = v9fs_fid_lookup(dentry->d_parent, FID_WALK); | |
78 | if (!v9fid) | |
79 | return -EBADF; | |
80 | ||
81 | newfid = v9fs_get_idpool(&v9ses->fidpool); | |
82 | if (newfid < 0) { | |
83 | eprintk(KERN_WARNING, "newfid fails!\n"); | |
84 | return -ENOSPC; | |
85 | } | |
86 | ||
87 | result = | |
88 | v9fs_t_walk(v9ses, v9fid->fid, newfid, | |
89 | (char *)file->f_dentry->d_name.name, NULL); | |
90 | if (result < 0) { | |
91 | v9fs_put_idpool(newfid, &v9ses->fidpool); | |
92 | dprintk(DEBUG_ERROR, "rewalk didn't work\n"); | |
93 | return -EBADF; | |
94 | } | |
95 | ||
96 | v9fid = v9fs_fid_create(dentry); | |
97 | if (v9fid == NULL) { | |
98 | dprintk(DEBUG_ERROR, "couldn't insert\n"); | |
99 | return -ENOMEM; | |
100 | } | |
101 | v9fid->fid = newfid; | |
102 | } | |
103 | ||
104 | if (v9fid->fidcreate) { | |
105 | /* create case */ | |
106 | newfid = v9fid->fid; | |
107 | iounit = v9fid->iounit; | |
108 | v9fid->fidcreate = 0; | |
109 | } else { | |
110 | if (!S_ISDIR(inode->i_mode)) | |
111 | newfid = v9fid->fid; | |
112 | else { | |
113 | newfid = v9fs_get_idpool(&v9ses->fidpool); | |
114 | if (newfid < 0) { | |
115 | eprintk(KERN_WARNING, "allocation failed\n"); | |
116 | return -ENOSPC; | |
117 | } | |
118 | /* This would be a somewhat critical clone */ | |
119 | result = | |
120 | v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, | |
121 | &fcall); | |
122 | if (result < 0) { | |
123 | dprintk(DEBUG_ERROR, "clone error: %s\n", | |
124 | FCALL_ERROR(fcall)); | |
125 | kfree(fcall); | |
126 | return result; | |
127 | } | |
128 | ||
129 | v9newfid = v9fs_fid_create(file->f_dentry); | |
130 | v9newfid->fid = newfid; | |
131 | v9newfid->qid = v9fid->qid; | |
132 | v9newfid->iounit = v9fid->iounit; | |
133 | v9newfid->fidopen = 0; | |
134 | v9newfid->fidclunked = 0; | |
135 | v9newfid->v9ses = v9ses; | |
136 | v9fid = v9newfid; | |
137 | kfree(fcall); | |
138 | } | |
139 | ||
140 | /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */ | |
141 | /* translate open mode appropriately */ | |
142 | open_mode = file->f_flags & 0x3; | |
143 | ||
144 | if (file->f_flags & O_EXCL) | |
145 | open_mode |= V9FS_OEXCL; | |
146 | ||
147 | if (v9ses->extended) { | |
148 | if (file->f_flags & O_TRUNC) | |
149 | open_mode |= V9FS_OTRUNC; | |
150 | ||
151 | if (file->f_flags & O_APPEND) | |
152 | open_mode |= V9FS_OAPPEND; | |
153 | } | |
154 | ||
155 | result = v9fs_t_open(v9ses, newfid, open_mode, &fcall); | |
156 | if (result < 0) { | |
157 | dprintk(DEBUG_ERROR, | |
158 | "open failed, open_mode 0x%x: %s\n", open_mode, | |
159 | FCALL_ERROR(fcall)); | |
160 | kfree(fcall); | |
161 | return result; | |
162 | } | |
163 | ||
164 | iounit = fcall->params.ropen.iounit; | |
165 | kfree(fcall); | |
166 | } | |
167 | ||
168 | ||
169 | file->private_data = v9fid; | |
170 | ||
171 | v9fid->rdir_pos = 0; | |
172 | v9fid->rdir_fcall = NULL; | |
173 | v9fid->fidopen = 1; | |
174 | v9fid->filp = file; | |
175 | v9fid->iounit = iounit; | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
180 | /** | |
181 | * v9fs_file_lock - lock a file (or directory) | |
182 | * @inode: inode to be opened | |
183 | * @file: file being opened | |
184 | * | |
185 | * XXX - this looks like a local only lock, we should extend into 9P | |
186 | * by using open exclusive | |
187 | */ | |
188 | ||
189 | static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) | |
190 | { | |
191 | int res = 0; | |
192 | struct inode *inode = filp->f_dentry->d_inode; | |
193 | ||
194 | dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); | |
195 | ||
196 | /* No mandatory locks */ | |
197 | if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) | |
198 | return -ENOLCK; | |
199 | ||
200 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { | |
201 | filemap_fdatawrite(inode->i_mapping); | |
202 | filemap_fdatawait(inode->i_mapping); | |
203 | invalidate_inode_pages(&inode->i_data); | |
204 | } | |
205 | ||
206 | return res; | |
207 | } | |
208 | ||
209 | /** | |
210 | * v9fs_read - read from a file (internal) | |
211 | * @filep: file pointer to read | |
212 | * @data: data buffer to read data into | |
213 | * @count: size of buffer | |
214 | * @offset: offset at which to read data | |
215 | * | |
216 | */ | |
217 | ||
218 | static ssize_t | |
219 | v9fs_read(struct file *filp, char *buffer, size_t count, loff_t * offset) | |
220 | { | |
221 | struct inode *inode = filp->f_dentry->d_inode; | |
222 | struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); | |
223 | struct v9fs_fid *v9f = filp->private_data; | |
224 | struct v9fs_fcall *fcall = NULL; | |
225 | int fid = v9f->fid; | |
226 | int rsize = 0; | |
227 | int result = 0; | |
228 | int total = 0; | |
229 | ||
230 | dprintk(DEBUG_VFS, "\n"); | |
231 | ||
232 | rsize = v9ses->maxdata - V9FS_IOHDRSZ; | |
233 | if (v9f->iounit != 0 && rsize > v9f->iounit) | |
234 | rsize = v9f->iounit; | |
235 | ||
236 | do { | |
237 | if (count < rsize) | |
238 | rsize = count; | |
239 | ||
240 | result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); | |
241 | ||
242 | if (result < 0) { | |
243 | printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", | |
244 | result); | |
245 | ||
246 | kfree(fcall); | |
247 | return total; | |
248 | } else | |
249 | *offset += result; | |
250 | ||
251 | /* XXX - extra copy */ | |
252 | memcpy(buffer, fcall->params.rread.data, result); | |
253 | count -= result; | |
254 | buffer += result; | |
255 | total += result; | |
256 | ||
257 | kfree(fcall); | |
258 | ||
259 | if (result < rsize) | |
260 | break; | |
261 | } while (count); | |
262 | ||
263 | return total; | |
264 | } | |
265 | ||
266 | /** | |
267 | * v9fs_file_read - read from a file | |
268 | * @filep: file pointer to read | |
269 | * @data: data buffer to read data into | |
270 | * @count: size of buffer | |
271 | * @offset: offset at which to read data | |
272 | * | |
273 | */ | |
274 | ||
275 | static ssize_t | |
276 | v9fs_file_read(struct file *filp, char __user * data, size_t count, | |
277 | loff_t * offset) | |
278 | { | |
279 | int retval = -1; | |
280 | int ret = 0; | |
281 | char *buffer; | |
282 | ||
283 | buffer = kmalloc(count, GFP_KERNEL); | |
284 | if (!buffer) | |
285 | return -ENOMEM; | |
286 | ||
287 | retval = v9fs_read(filp, buffer, count, offset); | |
288 | if (retval > 0) { | |
289 | if ((ret = copy_to_user(data, buffer, retval)) != 0) { | |
290 | dprintk(DEBUG_ERROR, "Problem copying to user %d\n", | |
291 | ret); | |
292 | retval = ret; | |
293 | } | |
294 | } | |
295 | ||
296 | kfree(buffer); | |
297 | ||
298 | return retval; | |
299 | } | |
300 | ||
301 | /** | |
302 | * v9fs_write - write to a file | |
303 | * @filep: file pointer to write | |
304 | * @data: data buffer to write data from | |
305 | * @count: size of buffer | |
306 | * @offset: offset at which to write data | |
307 | * | |
308 | */ | |
309 | ||
310 | static ssize_t | |
311 | v9fs_write(struct file *filp, char *buffer, size_t count, loff_t * offset) | |
312 | { | |
313 | struct inode *inode = filp->f_dentry->d_inode; | |
314 | struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); | |
315 | struct v9fs_fid *v9fid = filp->private_data; | |
316 | struct v9fs_fcall *fcall; | |
317 | int fid = v9fid->fid; | |
318 | int result = -EIO; | |
319 | int rsize = 0; | |
320 | int total = 0; | |
321 | ||
322 | dprintk(DEBUG_VFS, "data %p count %d offset %x\n", buffer, (int)count, | |
323 | (int)*offset); | |
324 | rsize = v9ses->maxdata - V9FS_IOHDRSZ; | |
325 | if (v9fid->iounit != 0 && rsize > v9fid->iounit) | |
326 | rsize = v9fid->iounit; | |
327 | ||
328 | dump_data(buffer, count); | |
329 | ||
330 | do { | |
331 | if (count < rsize) | |
332 | rsize = count; | |
333 | ||
334 | result = | |
335 | v9fs_t_write(v9ses, fid, *offset, rsize, buffer, &fcall); | |
336 | if (result < 0) { | |
337 | eprintk(KERN_ERR, "error while writing: %s(%d)\n", | |
338 | FCALL_ERROR(fcall), result); | |
339 | kfree(fcall); | |
340 | return result; | |
341 | } else | |
342 | *offset += result; | |
343 | ||
344 | kfree(fcall); | |
345 | ||
346 | if (result != rsize) { | |
347 | eprintk(KERN_ERR, | |
348 | "short write: v9fs_t_write returned %d\n", | |
349 | result); | |
350 | break; | |
351 | } | |
352 | ||
353 | count -= result; | |
354 | buffer += result; | |
355 | total += result; | |
356 | } while (count); | |
357 | ||
358 | return total; | |
359 | } | |
360 | ||
361 | /** | |
362 | * v9fs_file_write - write to a file | |
363 | * @filep: file pointer to write | |
364 | * @data: data buffer to write data from | |
365 | * @count: size of buffer | |
366 | * @offset: offset at which to write data | |
367 | * | |
368 | */ | |
369 | ||
370 | static ssize_t | |
371 | v9fs_file_write(struct file *filp, const char __user * data, | |
372 | size_t count, loff_t * offset) | |
373 | { | |
374 | int ret = -1; | |
375 | char *buffer; | |
376 | ||
377 | buffer = kmalloc(count, GFP_KERNEL); | |
378 | if (buffer == NULL) | |
379 | return -ENOMEM; | |
380 | ||
381 | ret = copy_from_user(buffer, data, count); | |
382 | if (ret) { | |
383 | dprintk(DEBUG_ERROR, "Problem copying from user\n"); | |
384 | ret = -EFAULT; | |
385 | } else { | |
386 | ret = v9fs_write(filp, buffer, count, offset); | |
387 | } | |
388 | ||
389 | kfree(buffer); | |
390 | ||
391 | return ret; | |
392 | } | |
393 | ||
394 | struct file_operations v9fs_file_operations = { | |
395 | .llseek = generic_file_llseek, | |
396 | .read = v9fs_file_read, | |
397 | .write = v9fs_file_write, | |
398 | .open = v9fs_file_open, | |
399 | .release = v9fs_dir_release, | |
400 | .lock = v9fs_file_lock, | |
401 | }; |