summaryrefslogtreecommitdiffstats
path: root/fs/smbfs/file.c
blob: 3c6eb3ba718e28b10c786fcbde4c95e811b364a2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
/*
 *  file.c
 *
 *  Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
 *  Copyright (C) 1997 by Volker Lendecke
 *
 *  Please add a note about your changes to smbfs in the ChangeLog file.
 */

#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include <linux/net.h>

#include <asm/uaccess.h>
#include <asm/system.h>

#include <linux/smbno.h>
#include <linux/smb_fs.h>

#include "smb_debug.h"
#include "proto.h"

static int
smb_fsync(struct file *file, struct dentry * dentry, int datasync)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	int result;

	VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));

	/*
	 * The VFS will writepage() all dirty pages for us, but we
	 * should send a SMBflush to the server, letting it know that
	 * we want things synchronized with actual storage.
	 *
	 * Note: this function requires all pages to have been written already
	 *       (should be ok with writepage_sync)
	 */
	result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
	return result;
}

/*
 * Read a page synchronously.
 */
static int
smb_readpage_sync(struct dentry *dentry, struct page *page)
{
	char *buffer = kmap(page);
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	struct smb_sb_info *server = server_from_dentry(dentry);
	unsigned int rsize = smb_get_rsize(server);
	int count = PAGE_SIZE;
	int result;

	VERBOSE("file %s/%s, count=%d@%Ld, rsize=%d\n",
		DENTRY_PATH(dentry), count, offset, rsize);

	result = smb_open(dentry, SMB_O_RDONLY);
	if (result < 0)
		goto io_error;

	do {
		if (count < rsize)
			rsize = count;

		result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
		if (result < 0)
			goto io_error;

		count -= result;
		offset += result;
		buffer += result;
		dentry->d_inode->i_atime =
			current_fs_time(dentry->d_inode->i_sb);
		if (result < rsize)
			break;
	} while (count);

	memset(buffer, 0, count);
	flush_dcache_page(page);
	SetPageUptodate(page);
	result = 0;

io_error:
	kunmap(page);
	unlock_page(page);
	return result;
}

/*
 * We are called with the page locked and we unlock it when done.
 */
static int
smb_readpage(struct file *file, struct page *page)
{
	int		error;
	struct dentry  *dentry = file->f_dentry;

	page_cache_get(page);
	error = smb_readpage_sync(dentry, page);
	page_cache_release(page);
	return error;
}

/*
 * Write a page synchronously.
 * Offset is the data offset within the page.
 */
static int
smb_writepage_sync(struct inode *inode, struct page *page,
		   unsigned long pageoffset, unsigned int count)
{
	loff_t offset;
	char *buffer = kmap(page) + pageoffset;
	struct smb_sb_info *server = server_from_inode(inode);
	unsigned int wsize = smb_get_wsize(server);
	int ret = 0;

	offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
	VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
		inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);

	do {
		int write_ret;

		if (count < wsize)
			wsize = count;

		write_ret = server->ops->write(inode, offset, wsize, buffer);
		if (write_ret < 0) {
			PARANOIA("failed write, wsize=%d, write_ret=%d\n",
				 wsize, write_ret);
			ret = write_ret;
			break;
		}
		/* N.B. what if result < wsize?? */
#ifdef SMBFS_PARANOIA
		if (write_ret < wsize)
			PARANOIA("short write, wsize=%d, write_ret=%d\n",
				 wsize, write_ret);
#endif
		buffer += wsize;
		offset += wsize;
		count -= wsize;
		/*
		 * Update the inode now rather than waiting for a refresh.
		 */
		inode->i_mtime = inode->i_atime = current_fs_time(inode->i_sb);
		SMB_I(inode)->flags |= SMB_F_LOCALWRITE;
		if (offset > inode->i_size)
			inode->i_size = offset;
	} while (count);

	kunmap(page);
	return ret;
}

/*
 * Write a page to the server. This will be used for NFS swapping only
 * (for now), and we currently do this synchronously only.
 *
 * We are called with the page locked and we unlock it when done.
 */
static int
smb_writepage(struct page *page, struct writeback_control *wbc)
{
	struct address_space *mapping = page->mapping;
	struct inode *inode;
	unsigned long end_index;
	unsigned offset = PAGE_CACHE_SIZE;
	int err;

	if (!mapping)
		BUG();
	inode = mapping->host;
	if (!inode)
		BUG();

	end_index = inode->i_size >> PAGE_CACHE_SHIFT;

	/* easy case */
	if (page->index < end_index)
		goto do_it;
	/* things got complicated... */
	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
	/* OK, are we completely out? */
	if (page->index >= end_index+1 || !offset)
		return 0; /* truncated - don't care */
do_it:
	page_cache_get(page);
	err = smb_writepage_sync(inode, page, 0, offset);
	SetPageUptodate(page);
	unlock_page(page);
	page_cache_release(page);
	return err;
}

static int
smb_updatepage(struct file *file, struct page *page, unsigned long offset,
	       unsigned int count)
{
	struct dentry *dentry = file->f_dentry;

	DEBUG1("(%s/%s %d@%ld)\n", DENTRY_PATH(dentry), 
	       count, (page->index << PAGE_CACHE_SHIFT)+offset);

	return smb_writepage_sync(dentry->d_inode, page, offset, count);
}

static ssize_t
smb_file_read(struct file * file, char __user * buf, size_t count, loff_t *ppos)
{
	struct dentry * dentry = file->f_dentry;
	ssize_t	status;

	VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
		(unsigned long) count, (unsigned long) *ppos);

	status = smb_revalidate_inode(dentry);
	if (status) {
		PARANOIA("%s/%s validation failed, error=%Zd\n",
			 DENTRY_PATH(dentry), status);
		goto out;
	}

	VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
		(long)dentry->d_inode->i_size,
		dentry->d_inode->i_flags, dentry->d_inode->i_atime);

	status = generic_file_read(file, buf, count, ppos);
out:
	return status;
}

static int
smb_file_mmap(struct file * file, struct vm_area_struct * vma)
{
	struct dentry * dentry = file->f_dentry;
	int	status;

	VERBOSE("file %s/%s, address %lu - %lu\n",
		DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);

	status = smb_revalidate_inode(dentry);
	if (status) {
		PARANOIA("%s/%s validation failed, error=%d\n",
			 DENTRY_PATH(dentry), status);
		goto out;
	}
	status = generic_file_mmap(file, vma);
out:
	return status;
}

static ssize_t
smb_file_sendfile(struct file *file, loff_t *ppos,
		  size_t count, read_actor_t actor, void *target)
{
	struct dentry *dentry = file->f_dentry;
	ssize_t status;

	VERBOSE("file %s/%s, pos=%Ld, count=%d\n",
		DENTRY_PATH(dentry), *ppos, count);

	status = smb_revalidate_inode(dentry);
	if (status) {
		PARANOIA("%s/%s validation failed, error=%Zd\n",
			 DENTRY_PATH(dentry), status);
		goto out;
	}
	status = generic_file_sendfile(file, ppos, count, actor, target);
out:
	return status;
}

/*
 * This does the "real" work of the write. The generic routine has
 * allocated the page, locked it, done all the page alignment stuff
 * calculations etc. Now we should just copy the data from user
 * space and write it back to the real medium..
 *
 * If the writer ends up delaying the write, the writer needs to
 * increment the page use counts until he is done with the page.
 */
static int smb_prepare_write(struct file *file, struct page *page, 
			     unsigned offset, unsigned to)
{
	return 0;
}

static int smb_commit_write(struct file *file, struct page *page,
			    unsigned offset, unsigned to)
{
	int status;

	status = -EFAULT;
	lock_kernel();
	status = smb_updatepage(file, page, offset, to-offset);
	unlock_kernel();
	return status;
}

struct address_space_operations smb_file_aops = {
	.readpage = smb_readpage,
	.writepage = smb_writepage,
	.prepare_write = smb_prepare_write,
	.commit_write = smb_commit_write
};

/* 
 * Write to a file (through the page cache).
 */
static ssize_t
smb_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	struct dentry * dentry = file->f_dentry;
	ssize_t	result;

	VERBOSE("file %s/%s, count=%lu@%lu\n",
		DENTRY_PATH(dentry),
		(unsigned long) count, (unsigned long) *ppos);

	result = smb_revalidate_inode(dentry);
	if (result) {
		PARANOIA("%s/%s validation failed, error=%Zd\n",
			 DENTRY_PATH(dentry), result);
		goto out;
	}

	result = smb_open(dentry, SMB_O_WRONLY);
	if (result)
		goto out;

	if (count > 0) {
		result = generic_file_write(file, buf, count, ppos);
		VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
			(long) file->f_pos, (long) dentry->d_inode->i_size,
			dentry->d_inode->i_mtime, dentry->d_inode->i_atime);
	}
out:
	return result;
}

static int
smb_file_open(struct inode *inode, struct file * file)
{
	int result;
	struct dentry *dentry = file->f_dentry;
	int smb_mode = (file->f_mode & O_ACCMODE) - 1;

	lock_kernel();
	result = smb_open(dentry, smb_mode);
	if (result)
		goto out;
	SMB_I(inode)->openers++;
out:
	unlock_kernel();
	return result;
}

static int
smb_file_release(struct inode *inode, struct file * file)
{
	lock_kernel();
	if (!--SMB_I(inode)->openers) {
		/* We must flush any dirty pages now as we won't be able to
		   write anything after close. mmap can trigger this.
		   "openers" should perhaps include mmap'ers ... */
		filemap_write_and_wait(inode->i_mapping);
		smb_close(inode);
	}
	unlock_kernel();
	return 0;
}

/*
 * Check whether the required access is compatible with
 * an inode's permission. SMB doesn't recognize superuser
 * privileges, so we need our own check for this.
 */
static int
smb_file_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	int mode = inode->i_mode;
	int error = 0;

	VERBOSE("mode=%x, mask=%x\n", mode, mask);

	/* Look at user permissions */
	mode >>= 6;
	if ((mode & 7 & mask) != mask)
		error = -EACCES;
	return error;
}

struct file_operations smb_file_operations =
{
	.llseek		= remote_llseek,
	.read		= smb_file_read,
	.write		= smb_file_write,
	.ioctl		= smb_ioctl,
	.mmap		= smb_file_mmap,
	.open		= smb_file_open,
	.release	= smb_file_release,
	.fsync		= smb_fsync,
	.sendfile	= smb_file_sendfile,
};

struct inode_operations smb_file_inode_operations =
{
	.permission	= smb_file_permission,
	.getattr	= smb_getattr,
	.setattr	= smb_notify_change,
};
OpenPOWER on IntegriCloud