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-rw-r--r--fs/9p/vfs_file.c401
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diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
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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
53int 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
189static 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
218static ssize_t
219v9fs_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
275static ssize_t
276v9fs_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
310static ssize_t
311v9fs_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
370static ssize_t
371v9fs_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
394struct 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};