1 /*
2 * file.c
3 *
4 * Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
5 * Copyright (C) 1997 by Volker Lendecke
6 *
7 * Please add a note about your changes to smbfs in the ChangeLog file.
8 */
9
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/fcntl.h>
14 #include <linux/stat.h>
15 #include <linux/mm.h>
16 #include <linux/slab.h>
17 #include <linux/pagemap.h>
18 #include <linux/smp_lock.h>
19
20 #include <asm/uaccess.h>
21 #include <asm/system.h>
22
23 #include <linux/smbno.h>
24 #include <linux/smb_fs.h>
25
26 #include "smb_debug.h"
27 #include "proto.h"
28
29 static int
smb_fsync(struct file * file,struct dentry * dentry,int datasync)30 smb_fsync(struct file *file, struct dentry * dentry, int datasync)
31 {
32 struct smb_sb_info *server = server_from_dentry(dentry);
33 int result;
34
35 VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));
36
37 /*
38 * The VFS will writepage() all dirty pages for us, but we
39 * should send a SMBflush to the server, letting it know that
40 * we want things synchronized with actual storage.
41 *
42 * Note: this function requires all pages to have been written already
43 * (should be ok with writepage_sync)
44 */
45 smb_lock_server(server);
46 result = smb_proc_flush(server, dentry->d_inode->u.smbfs_i.fileid);
47 smb_unlock_server(server);
48 return result;
49 }
50
51 /*
52 * Read a page synchronously.
53 */
54 static int
smb_readpage_sync(struct dentry * dentry,struct page * page)55 smb_readpage_sync(struct dentry *dentry, struct page *page)
56 {
57 char *buffer = kmap(page);
58 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
59 struct smb_sb_info *server = server_from_dentry(dentry);
60 unsigned int rsize = smb_get_rsize(server);
61 int count = PAGE_SIZE;
62 int result;
63
64 VERBOSE("file %s/%s, count=%d@%ld, rsize=%d\n",
65 DENTRY_PATH(dentry), count, offset, rsize);
66
67 result = smb_open(dentry, SMB_O_RDONLY);
68 if (result < 0) {
69 PARANOIA("%s/%s open failed, error=%d\n",
70 DENTRY_PATH(dentry), result);
71 goto io_error;
72 }
73
74 do {
75 if (count < rsize)
76 rsize = count;
77
78 result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
79 if (result < 0)
80 goto io_error;
81
82 count -= result;
83 offset += result;
84 buffer += result;
85 dentry->d_inode->i_atime = CURRENT_TIME;
86 if (result < rsize)
87 break;
88 } while (count);
89
90 memset(buffer, 0, count);
91 flush_dcache_page(page);
92 SetPageUptodate(page);
93 result = 0;
94
95 io_error:
96 kunmap(page);
97 UnlockPage(page);
98 return result;
99 }
100
101 /*
102 * We are called with the page locked and we unlock it when done.
103 */
104 static int
smb_readpage(struct file * file,struct page * page)105 smb_readpage(struct file *file, struct page *page)
106 {
107 int error;
108 struct dentry *dentry = file->f_dentry;
109
110 get_page(page);
111 error = smb_readpage_sync(dentry, page);
112 put_page(page);
113 return error;
114 }
115
116 /*
117 * Write a page synchronously.
118 * Offset is the data offset within the page.
119 */
120 static int
smb_writepage_sync(struct inode * inode,struct page * page,unsigned long pageoffset,unsigned int count)121 smb_writepage_sync(struct inode *inode, struct page *page,
122 unsigned long pageoffset, unsigned int count)
123 {
124 loff_t offset;
125 char *buffer = kmap(page) + pageoffset;
126 struct smb_sb_info *server = server_from_inode(inode);
127 unsigned int wsize = smb_get_wsize(server);
128 int result, written = 0;
129
130 offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
131 VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
132 inode->i_ino, inode->u.smbfs_i.fileid, count, offset, wsize);
133
134 do {
135 if (count < wsize)
136 wsize = count;
137
138 result = server->ops->write(inode, offset, wsize, buffer);
139 if (result < 0) {
140 PARANOIA("failed write, wsize=%d, result=%d\n",
141 wsize, result);
142 break;
143 }
144 /* N.B. what if result < wsize?? */
145 #ifdef SMBFS_PARANOIA
146 if (result < wsize)
147 PARANOIA("short write, wsize=%d, result=%d\n",
148 wsize, result);
149 #endif
150 buffer += wsize;
151 offset += wsize;
152 written += wsize;
153 count -= wsize;
154 /*
155 * Update the inode now rather than waiting for a refresh.
156 */
157 inode->i_mtime = inode->i_atime = CURRENT_TIME;
158 inode->u.smbfs_i.flags |= SMB_F_LOCALWRITE;
159 if (offset > inode->i_size)
160 inode->i_size = offset;
161 } while (count);
162
163 kunmap(page);
164 return written ? written : result;
165 }
166
167 /*
168 * Write a page to the server. This will be used for NFS swapping only
169 * (for now), and we currently do this synchronously only.
170 *
171 * We are called with the page locked and we unlock it when done.
172 */
173 static int
smb_writepage(struct page * page)174 smb_writepage(struct page *page)
175 {
176 struct address_space *mapping = page->mapping;
177 struct inode *inode;
178 unsigned long end_index;
179 unsigned offset = PAGE_CACHE_SIZE;
180 int err;
181
182 if (!mapping)
183 BUG();
184 inode = mapping->host;
185 if (!inode)
186 BUG();
187
188 end_index = inode->i_size >> PAGE_CACHE_SHIFT;
189
190 /* easy case */
191 if (page->index < end_index)
192 goto do_it;
193 /* things got complicated... */
194 offset = inode->i_size & (PAGE_CACHE_SIZE-1);
195 /* OK, are we completely out? */
196 if (page->index >= end_index+1 || !offset)
197 return -EIO;
198 do_it:
199 get_page(page);
200 err = smb_writepage_sync(inode, page, 0, offset);
201 SetPageUptodate(page);
202 UnlockPage(page);
203 put_page(page);
204 return err;
205 }
206
207 static int
smb_updatepage(struct file * file,struct page * page,unsigned long offset,unsigned int count)208 smb_updatepage(struct file *file, struct page *page, unsigned long offset,
209 unsigned int count)
210 {
211 struct dentry *dentry = file->f_dentry;
212
213 DEBUG1("(%s/%s %d@%ld)\n", DENTRY_PATH(dentry),
214 count, (page->index << PAGE_CACHE_SHIFT)+offset);
215
216 return smb_writepage_sync(dentry->d_inode, page, offset, count);
217 }
218
219 static ssize_t
smb_file_read(struct file * file,char * buf,size_t count,loff_t * ppos)220 smb_file_read(struct file * file, char * buf, size_t count, loff_t *ppos)
221 {
222 struct dentry * dentry = file->f_dentry;
223 ssize_t status;
224
225 VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
226 (unsigned long) count, (unsigned long) *ppos);
227
228 status = smb_revalidate_inode(dentry);
229 if (status) {
230 PARANOIA("%s/%s validation failed, error=%Zd\n",
231 DENTRY_PATH(dentry), status);
232 goto out;
233 }
234
235 VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
236 (long)dentry->d_inode->i_size,
237 dentry->d_inode->i_flags, dentry->d_inode->i_atime);
238
239 status = generic_file_read(file, buf, count, ppos);
240 out:
241 return status;
242 }
243
244 static int
smb_file_mmap(struct file * file,struct vm_area_struct * vma)245 smb_file_mmap(struct file * file, struct vm_area_struct * vma)
246 {
247 struct dentry * dentry = file->f_dentry;
248 int status;
249
250 VERBOSE("file %s/%s, address %lu - %lu\n",
251 DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);
252
253 status = smb_revalidate_inode(dentry);
254 if (status) {
255 PARANOIA("%s/%s validation failed, error=%d\n",
256 DENTRY_PATH(dentry), status);
257 goto out;
258 }
259 status = generic_file_mmap(file, vma);
260 out:
261 return status;
262 }
263
264 /*
265 * This does the "real" work of the write. The generic routine has
266 * allocated the page, locked it, done all the page alignment stuff
267 * calculations etc. Now we should just copy the data from user
268 * space and write it back to the real medium..
269 *
270 * If the writer ends up delaying the write, the writer needs to
271 * increment the page use counts until he is done with the page.
272 */
smb_prepare_write(struct file * file,struct page * page,unsigned offset,unsigned to)273 static int smb_prepare_write(struct file *file, struct page *page,
274 unsigned offset, unsigned to)
275 {
276 return 0;
277 }
278
smb_commit_write(struct file * file,struct page * page,unsigned offset,unsigned to)279 static int smb_commit_write(struct file *file, struct page *page,
280 unsigned offset, unsigned to)
281 {
282 int status;
283
284 status = -EFAULT;
285 lock_kernel();
286 status = smb_updatepage(file, page, offset, to-offset);
287 unlock_kernel();
288 return status;
289 }
290
291 struct address_space_operations smb_file_aops = {
292 readpage: smb_readpage,
293 writepage: smb_writepage,
294 prepare_write: smb_prepare_write,
295 commit_write: smb_commit_write
296 };
297
298 /*
299 * Write to a file (through the page cache).
300 */
301 static ssize_t
smb_file_write(struct file * file,const char * buf,size_t count,loff_t * ppos)302 smb_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
303 {
304 struct dentry * dentry = file->f_dentry;
305 ssize_t result;
306
307 VERBOSE("file %s/%s, count=%lu@%lu\n",
308 DENTRY_PATH(dentry),
309 (unsigned long) count, (unsigned long) *ppos);
310
311 result = smb_revalidate_inode(dentry);
312 if (result) {
313 PARANOIA("%s/%s validation failed, error=%Zd\n",
314 DENTRY_PATH(dentry), result);
315 goto out;
316 }
317
318 result = smb_open(dentry, SMB_O_WRONLY);
319 if (result)
320 goto out;
321
322 if (count > 0) {
323 result = generic_file_write(file, buf, count, ppos);
324 VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
325 (long) file->f_pos, (long) dentry->d_inode->i_size,
326 dentry->d_inode->i_mtime, dentry->d_inode->i_atime);
327 }
328 out:
329 return result;
330 }
331
332 static int
smb_file_open(struct inode * inode,struct file * file)333 smb_file_open(struct inode *inode, struct file * file)
334 {
335 int result;
336 struct dentry *dentry = file->f_dentry;
337 int smb_mode = (file->f_mode & O_ACCMODE) - 1;
338
339 lock_kernel();
340 result = smb_open(dentry, smb_mode);
341 if (result)
342 goto out;
343 inode->u.smbfs_i.openers++;
344 out:
345 unlock_kernel();
346 return 0;
347 }
348
349 static int
smb_file_release(struct inode * inode,struct file * file)350 smb_file_release(struct inode *inode, struct file * file)
351 {
352 lock_kernel();
353 if (!--inode->u.smbfs_i.openers) {
354 /* We must flush any dirty pages now as we won't be able to
355 write anything after close. mmap can trigger this.
356 "openers" should perhaps include mmap'ers ... */
357 filemap_fdatasync(inode->i_mapping);
358 filemap_fdatawait(inode->i_mapping);
359 smb_close(inode);
360 }
361 unlock_kernel();
362 return 0;
363 }
364
365 /*
366 * Check whether the required access is compatible with
367 * an inode's permission. SMB doesn't recognize superuser
368 * privileges, so we need our own check for this.
369 */
370 static int
smb_file_permission(struct inode * inode,int mask)371 smb_file_permission(struct inode *inode, int mask)
372 {
373 int mode = inode->i_mode;
374 int error = 0;
375
376 VERBOSE("mode=%x, mask=%x\n", mode, mask);
377
378 /* Look at user permissions */
379 mode >>= 6;
380 if ((mode & 7 & mask) != mask)
381 error = -EACCES;
382 return error;
383 }
384
385 struct file_operations smb_file_operations =
386 {
387 llseek: generic_file_llseek,
388 read: smb_file_read,
389 write: smb_file_write,
390 ioctl: smb_ioctl,
391 mmap: smb_file_mmap,
392 open: smb_file_open,
393 release: smb_file_release,
394 fsync: smb_fsync,
395 };
396
397 struct inode_operations smb_file_inode_operations =
398 {
399 permission: smb_file_permission,
400 revalidate: smb_revalidate_inode,
401 setattr: smb_notify_change,
402 };
403