sys_sendfile: switch to using ->splice_read, if available
[deliverable/linux.git] / fs / smbfs / file.c
CommitLineData
1da177e4
LT
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/time.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#include <linux/net.h>
e8edc6e0 20#include <linux/aio.h>
1da177e4
LT
21
22#include <asm/uaccess.h>
23#include <asm/system.h>
24
25#include <linux/smbno.h>
26#include <linux/smb_fs.h>
27
28#include "smb_debug.h"
29#include "proto.h"
30
31static int
32smb_fsync(struct file *file, struct dentry * dentry, int datasync)
33{
34 struct smb_sb_info *server = server_from_dentry(dentry);
35 int result;
36
37 VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));
38
39 /*
40 * The VFS will writepage() all dirty pages for us, but we
41 * should send a SMBflush to the server, letting it know that
42 * we want things synchronized with actual storage.
43 *
44 * Note: this function requires all pages to have been written already
45 * (should be ok with writepage_sync)
46 */
47 result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
48 return result;
49}
50
51/*
52 * Read a page synchronously.
53 */
54static int
55smb_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 goto io_error;
70
71 do {
72 if (count < rsize)
73 rsize = count;
74
75 result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
76 if (result < 0)
77 goto io_error;
78
79 count -= result;
80 offset += result;
81 buffer += result;
82 dentry->d_inode->i_atime =
83 current_fs_time(dentry->d_inode->i_sb);
84 if (result < rsize)
85 break;
86 } while (count);
87
88 memset(buffer, 0, count);
89 flush_dcache_page(page);
90 SetPageUptodate(page);
91 result = 0;
92
93io_error:
94 kunmap(page);
95 unlock_page(page);
96 return result;
97}
98
99/*
100 * We are called with the page locked and we unlock it when done.
101 */
102static int
103smb_readpage(struct file *file, struct page *page)
104{
105 int error;
17b75e69 106 struct dentry *dentry = file->f_path.dentry;
1da177e4
LT
107
108 page_cache_get(page);
109 error = smb_readpage_sync(dentry, page);
110 page_cache_release(page);
111 return error;
112}
113
114/*
115 * Write a page synchronously.
116 * Offset is the data offset within the page.
117 */
118static int
119smb_writepage_sync(struct inode *inode, struct page *page,
120 unsigned long pageoffset, unsigned int count)
121{
122 loff_t offset;
123 char *buffer = kmap(page) + pageoffset;
124 struct smb_sb_info *server = server_from_inode(inode);
125 unsigned int wsize = smb_get_wsize(server);
126 int ret = 0;
127
128 offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
129 VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
130 inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);
131
132 do {
133 int write_ret;
134
135 if (count < wsize)
136 wsize = count;
137
138 write_ret = server->ops->write(inode, offset, wsize, buffer);
139 if (write_ret < 0) {
140 PARANOIA("failed write, wsize=%d, write_ret=%d\n",
141 wsize, write_ret);
142 ret = write_ret;
143 break;
144 }
145 /* N.B. what if result < wsize?? */
146#ifdef SMBFS_PARANOIA
147 if (write_ret < wsize)
148 PARANOIA("short write, wsize=%d, write_ret=%d\n",
149 wsize, write_ret);
150#endif
151 buffer += wsize;
152 offset += 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_fs_time(inode->i_sb);
158 SMB_I(inode)->flags |= SMB_F_LOCALWRITE;
159 if (offset > inode->i_size)
160 inode->i_size = offset;
161 } while (count);
162
163 kunmap(page);
164 return ret;
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 */
173static int
174smb_writepage(struct page *page, struct writeback_control *wbc)
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
5df0d312 182 BUG_ON(!mapping);
1da177e4 183 inode = mapping->host;
5df0d312 184 BUG_ON(!inode);
1da177e4
LT
185
186 end_index = inode->i_size >> PAGE_CACHE_SHIFT;
187
188 /* easy case */
189 if (page->index < end_index)
190 goto do_it;
191 /* things got complicated... */
192 offset = inode->i_size & (PAGE_CACHE_SIZE-1);
193 /* OK, are we completely out? */
194 if (page->index >= end_index+1 || !offset)
195 return 0; /* truncated - don't care */
196do_it:
197 page_cache_get(page);
198 err = smb_writepage_sync(inode, page, 0, offset);
199 SetPageUptodate(page);
200 unlock_page(page);
201 page_cache_release(page);
202 return err;
203}
204
205static int
206smb_updatepage(struct file *file, struct page *page, unsigned long offset,
207 unsigned int count)
208{
17b75e69 209 struct dentry *dentry = file->f_path.dentry;
1da177e4 210
54b21a79
AM
211 DEBUG1("(%s/%s %d@%lld)\n", DENTRY_PATH(dentry), count,
212 ((unsigned long long)page->index << PAGE_CACHE_SHIFT) + offset);
1da177e4
LT
213
214 return smb_writepage_sync(dentry->d_inode, page, offset, count);
215}
216
217static ssize_t
543ade1f
BP
218smb_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
219 unsigned long nr_segs, loff_t pos)
1da177e4 220{
543ade1f 221 struct file * file = iocb->ki_filp;
17b75e69 222 struct dentry * dentry = file->f_path.dentry;
1da177e4
LT
223 ssize_t status;
224
225 VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
543ade1f 226 (unsigned long) iocb->ki_left, (unsigned long) pos);
1da177e4
LT
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
543ade1f 239 status = generic_file_aio_read(iocb, iov, nr_segs, pos);
1da177e4
LT
240out:
241 return status;
242}
243
244static int
245smb_file_mmap(struct file * file, struct vm_area_struct * vma)
246{
17b75e69 247 struct dentry * dentry = file->f_path.dentry;
1da177e4
LT
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);
260out:
261 return status;
262}
263
264static ssize_t
265smb_file_sendfile(struct file *file, loff_t *ppos,
266 size_t count, read_actor_t actor, void *target)
267{
17b75e69 268 struct dentry *dentry = file->f_path.dentry;
1da177e4
LT
269 ssize_t status;
270
271 VERBOSE("file %s/%s, pos=%Ld, count=%d\n",
272 DENTRY_PATH(dentry), *ppos, count);
273
274 status = smb_revalidate_inode(dentry);
275 if (status) {
276 PARANOIA("%s/%s validation failed, error=%Zd\n",
277 DENTRY_PATH(dentry), status);
278 goto out;
279 }
280 status = generic_file_sendfile(file, ppos, count, actor, target);
281out:
282 return status;
283}
284
285/*
286 * This does the "real" work of the write. The generic routine has
287 * allocated the page, locked it, done all the page alignment stuff
288 * calculations etc. Now we should just copy the data from user
289 * space and write it back to the real medium..
290 *
291 * If the writer ends up delaying the write, the writer needs to
292 * increment the page use counts until he is done with the page.
293 */
294static int smb_prepare_write(struct file *file, struct page *page,
295 unsigned offset, unsigned to)
296{
297 return 0;
298}
299
300static int smb_commit_write(struct file *file, struct page *page,
301 unsigned offset, unsigned to)
302{
303 int status;
304
305 status = -EFAULT;
306 lock_kernel();
307 status = smb_updatepage(file, page, offset, to-offset);
308 unlock_kernel();
309 return status;
310}
311
f5e54d6e 312const struct address_space_operations smb_file_aops = {
1da177e4
LT
313 .readpage = smb_readpage,
314 .writepage = smb_writepage,
315 .prepare_write = smb_prepare_write,
316 .commit_write = smb_commit_write
317};
318
319/*
320 * Write to a file (through the page cache).
321 */
322static ssize_t
543ade1f
BP
323smb_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
324 unsigned long nr_segs, loff_t pos)
1da177e4 325{
543ade1f 326 struct file * file = iocb->ki_filp;
17b75e69 327 struct dentry * dentry = file->f_path.dentry;
1da177e4
LT
328 ssize_t result;
329
330 VERBOSE("file %s/%s, count=%lu@%lu\n",
331 DENTRY_PATH(dentry),
543ade1f 332 (unsigned long) iocb->ki_left, (unsigned long) pos);
1da177e4
LT
333
334 result = smb_revalidate_inode(dentry);
335 if (result) {
336 PARANOIA("%s/%s validation failed, error=%Zd\n",
337 DENTRY_PATH(dentry), result);
338 goto out;
339 }
340
341 result = smb_open(dentry, SMB_O_WRONLY);
342 if (result)
343 goto out;
344
543ade1f
BP
345 if (iocb->ki_left > 0) {
346 result = generic_file_aio_write(iocb, iov, nr_segs, pos);
1da177e4
LT
347 VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
348 (long) file->f_pos, (long) dentry->d_inode->i_size,
349 dentry->d_inode->i_mtime, dentry->d_inode->i_atime);
350 }
351out:
352 return result;
353}
354
355static int
356smb_file_open(struct inode *inode, struct file * file)
357{
358 int result;
17b75e69 359 struct dentry *dentry = file->f_path.dentry;
1da177e4
LT
360 int smb_mode = (file->f_mode & O_ACCMODE) - 1;
361
362 lock_kernel();
363 result = smb_open(dentry, smb_mode);
364 if (result)
365 goto out;
366 SMB_I(inode)->openers++;
367out:
368 unlock_kernel();
369 return result;
370}
371
372static int
373smb_file_release(struct inode *inode, struct file * file)
374{
375 lock_kernel();
376 if (!--SMB_I(inode)->openers) {
377 /* We must flush any dirty pages now as we won't be able to
378 write anything after close. mmap can trigger this.
379 "openers" should perhaps include mmap'ers ... */
28fd1298 380 filemap_write_and_wait(inode->i_mapping);
1da177e4
LT
381 smb_close(inode);
382 }
383 unlock_kernel();
384 return 0;
385}
386
387/*
388 * Check whether the required access is compatible with
389 * an inode's permission. SMB doesn't recognize superuser
390 * privileges, so we need our own check for this.
391 */
392static int
393smb_file_permission(struct inode *inode, int mask, struct nameidata *nd)
394{
395 int mode = inode->i_mode;
396 int error = 0;
397
398 VERBOSE("mode=%x, mask=%x\n", mode, mask);
399
400 /* Look at user permissions */
401 mode >>= 6;
402 if ((mode & 7 & mask) != mask)
403 error = -EACCES;
404 return error;
405}
406
4b6f5d20 407const struct file_operations smb_file_operations =
1da177e4
LT
408{
409 .llseek = remote_llseek,
543ade1f
BP
410 .read = do_sync_read,
411 .aio_read = smb_file_aio_read,
412 .write = do_sync_write,
413 .aio_write = smb_file_aio_write,
1da177e4
LT
414 .ioctl = smb_ioctl,
415 .mmap = smb_file_mmap,
416 .open = smb_file_open,
417 .release = smb_file_release,
418 .fsync = smb_fsync,
419 .sendfile = smb_file_sendfile,
420};
421
c5ef1c42 422const struct inode_operations smb_file_inode_operations =
1da177e4
LT
423{
424 .permission = smb_file_permission,
425 .getattr = smb_getattr,
426 .setattr = smb_notify_change,
427};
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