summaryrefslogtreecommitdiff
path: root/fs/gfs2/ops_address.c
blob: 005c2522a879b4e0a4abb1589909c6aa33d1b82f (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
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <asm/semaphore.h>

#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "ops_address.h"
#include "page.h"
#include "quota.h"
#include "trans.h"
#include "rgrp.h"
#include "ops_file.h"
#include "util.h"

/**
 * gfs2_get_block - Fills in a buffer head with details about a block
 * @inode: The inode
 * @lblock: The block number to look up
 * @bh_result: The buffer head to return the result in
 * @create: Non-zero if we may add block to the file
 *
 * Returns: errno
 */

int gfs2_get_block(struct inode *inode, sector_t lblock,
	           struct buffer_head *bh_result, int create)
{
	struct gfs2_inode *ip = inode->u.generic_ip;
	int new = create;
	uint64_t dblock;
	int error;

	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	if (error)
		return error;

	if (!dblock)
		return 0;

	map_bh(bh_result, inode->i_sb, dblock);
	if (new)
		set_buffer_new(bh_result);

	return 0;
}

/**
 * get_block_noalloc - Fills in a buffer head with details about a block
 * @inode: The inode
 * @lblock: The block number to look up
 * @bh_result: The buffer head to return the result in
 * @create: Non-zero if we may add block to the file
 *
 * Returns: errno
 */

static int get_block_noalloc(struct inode *inode, sector_t lblock,
			     struct buffer_head *bh_result, int create)
{
	struct gfs2_inode *ip = inode->u.generic_ip;
	int new = 0;
	uint64_t dblock;
	int error;

	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	if (error)
		return error;

	if (dblock)
		map_bh(bh_result, inode->i_sb, dblock);
	else if (gfs2_assert_withdraw(ip->i_sbd, !create))
		error = -EIO;

	return error;
}

/**
 * gfs2_writepage - Write complete page
 * @page: Page to write
 *
 * Returns: errno
 *
 * Some of this is copied from block_write_full_page() although we still
 * call it to do most of the work.
 */

static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
{
	struct inode *inode = page->mapping->host;
	struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
	struct gfs2_sbd *sdp = ip->i_sbd;
	loff_t i_size = i_size_read(inode);
	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
	unsigned offset;
	int error;
	int done_trans = 0;

	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
		unlock_page(page);
		return -EIO;
	}
	if (current->journal_info)
		goto out_ignore;

	/* Is the page fully outside i_size? (truncate in progress) */
        offset = i_size & (PAGE_CACHE_SIZE-1);
	if (page->index >= end_index+1 || !offset) {
		page->mapping->a_ops->invalidatepage(page, 0);
		unlock_page(page);
		return 0; /* don't care */
	}

	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
		error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
		if (error)
			goto out_ignore;
		gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
		done_trans = 1;
	}
	error = block_write_full_page(page, get_block_noalloc, wbc);
	if (done_trans)
		gfs2_trans_end(sdp);
	gfs2_meta_cache_flush(ip);
	return error;

out_ignore:
	redirty_page_for_writepage(wbc, page);
	unlock_page(page);
	return 0;
}

/**
 * stuffed_readpage - Fill in a Linux page with stuffed file data
 * @ip: the inode
 * @page: the page
 *
 * Returns: errno
 */

static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
{
	struct buffer_head *dibh;
	void *kaddr;
	int error;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		return error;

	kaddr = kmap_atomic(page, KM_USER0);
	memcpy((char *)kaddr,
	       dibh->b_data + sizeof(struct gfs2_dinode),
	       ip->i_di.di_size);
	memset((char *)kaddr + ip->i_di.di_size,
	       0,
	       PAGE_CACHE_SIZE - ip->i_di.di_size);
	kunmap_atomic(page, KM_USER0);

	brelse(dibh);

	SetPageUptodate(page);

	return 0;
}

static int zero_readpage(struct page *page)
{
	void *kaddr;

	kaddr = kmap_atomic(page, KM_USER0);
	memset(kaddr, 0, PAGE_CACHE_SIZE);
	kunmap_atomic(page, KM_USER0);

	SetPageUptodate(page);
	unlock_page(page);

	return 0;
}

/**
 * gfs2_readpage - readpage with locking
 * @file: The file to read a page for. N.B. This may be NULL if we are
 * reading an internal file.
 * @page: The page to read
 *
 * Returns: errno
 */

static int gfs2_readpage(struct file *file, struct page *page)
{
	struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
	struct gfs2_sbd *sdp = ip->i_sbd;
	struct gfs2_holder gh;
	int error;

	if (file != &gfs2_internal_file_sentinal) {
		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh);
		error = gfs2_glock_nq_m_atime(1, &gh);
		if (error)
			goto out_unlock;
	}

	if (gfs2_is_stuffed(ip)) {
		if (!page->index) {
			error = stuffed_readpage(ip, page);
			unlock_page(page);
		} else
			error = zero_readpage(page);
	} else
		error = mpage_readpage(page, gfs2_get_block);

	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		error = -EIO;

	if (file != &gfs2_internal_file_sentinal) {
		gfs2_glock_dq_m(1, &gh);
		gfs2_holder_uninit(&gh);
	}
out:
	return error;
out_unlock:
	unlock_page(page);
	goto out;
}

/**
 * gfs2_prepare_write - Prepare to write a page to a file
 * @file: The file to write to
 * @page: The page which is to be prepared for writing
 * @from: From (byte range within page)
 * @to: To (byte range within page)
 *
 * Returns: errno
 */

static int gfs2_prepare_write(struct file *file, struct page *page,
			      unsigned from, unsigned to)
{
	struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
	struct gfs2_sbd *sdp = ip->i_sbd;
	unsigned int data_blocks, ind_blocks, rblocks;
	int alloc_required;
	int error = 0;
	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
	loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
	struct gfs2_alloc *al;

	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh);
	error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
	if (error)
		goto out_uninit;

	gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);

	error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
	if (error)
		goto out_unlock;


	if (alloc_required) {
		al = gfs2_alloc_get(ip);

		error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
		if (error)
			goto out_alloc_put;

		error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
		if (error)
			goto out_qunlock;

		al->al_requested = data_blocks + ind_blocks;
		error = gfs2_inplace_reserve(ip);
		if (error)
			goto out_qunlock;
	}

	rblocks = RES_DINODE + ind_blocks;
	if (gfs2_is_jdata(ip))
		rblocks += data_blocks ? data_blocks : 1;
	if (ind_blocks || data_blocks)
		rblocks += RES_STATFS + RES_QUOTA;

	error = gfs2_trans_begin(sdp, rblocks, 0);
	if (error)
		goto out;

	if (gfs2_is_stuffed(ip)) {
		if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
			error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
						    page);
			if (error == 0)
				goto prepare_write;
		} else if (!PageUptodate(page))
			error = stuffed_readpage(ip, page);
		goto out;
	}

prepare_write:
	error = block_prepare_write(page, from, to, gfs2_get_block);

out:
	if (error) {
		gfs2_trans_end(sdp);
		if (alloc_required) {
			gfs2_inplace_release(ip);
out_qunlock:
			gfs2_quota_unlock(ip);
out_alloc_put:
			gfs2_alloc_put(ip);
		}
out_unlock:
		gfs2_glock_dq_m(1, &ip->i_gh);
out_uninit:
		gfs2_holder_uninit(&ip->i_gh);
	}

	return error;
}

/**
 * gfs2_commit_write - Commit write to a file
 * @file: The file to write to
 * @page: The page containing the data
 * @from: From (byte range within page)
 * @to: To (byte range within page)
 *
 * Returns: errno
 */

static int gfs2_commit_write(struct file *file, struct page *page,
			     unsigned from, unsigned to)
{
	struct inode *inode = page->mapping->host;
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct gfs2_sbd *sdp = ip->i_sbd;
	int error = -EOPNOTSUPP;
	struct buffer_head *dibh;
	struct gfs2_alloc *al = &ip->i_alloc;;

	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
                goto fail_nounlock;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		goto fail_endtrans;

	gfs2_trans_add_bh(ip->i_gl, dibh, 1);

	if (gfs2_is_stuffed(ip)) {
		uint64_t file_size;
		void *kaddr;

		file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;

		kaddr = kmap_atomic(page, KM_USER0);
		memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
		       (char *)kaddr + from, to - from);
		kunmap_atomic(page, KM_USER0);

		SetPageUptodate(page);

		if (inode->i_size < file_size)
			i_size_write(inode, file_size);
	} else {
		if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
		    gfs2_is_jdata(ip))
			gfs2_page_add_databufs(ip, page, from, to);
		error = generic_commit_write(file, page, from, to);
		if (error)
			goto fail;
	}

	if (ip->i_di.di_size < inode->i_size)
		ip->i_di.di_size = inode->i_size;

	gfs2_dinode_out(&ip->i_di, dibh->b_data);
	brelse(dibh);
	gfs2_trans_end(sdp);
	if (al->al_requested) {
		gfs2_inplace_release(ip);
		gfs2_quota_unlock(ip);
		gfs2_alloc_put(ip);
	}
	gfs2_glock_dq_m(1, &ip->i_gh);
	gfs2_holder_uninit(&ip->i_gh);
	return 0;

fail:
	brelse(dibh);
fail_endtrans:
	gfs2_trans_end(sdp);
	if (al->al_requested) {
		gfs2_inplace_release(ip);
		gfs2_quota_unlock(ip);
		gfs2_alloc_put(ip);
	}
	gfs2_glock_dq_m(1, &ip->i_gh);
	gfs2_holder_uninit(&ip->i_gh);
fail_nounlock:
	ClearPageUptodate(page);
	return error;
}

/**
 * gfs2_bmap - Block map function
 * @mapping: Address space info
 * @lblock: The block to map
 *
 * Returns: The disk address for the block or 0 on hole or error
 */

static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
{
	struct gfs2_inode *ip = mapping->host->u.generic_ip;
	struct gfs2_holder i_gh;
	sector_t dblock = 0;
	int error;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
	if (error)
		return 0;

	if (!gfs2_is_stuffed(ip))
		dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);

	gfs2_glock_dq_uninit(&i_gh);

	return dblock;
}

static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
{
	struct gfs2_bufdata *bd;

	gfs2_log_lock(sdp);
	bd = bh->b_private;
	if (bd) {
		bd->bd_bh = NULL;
		bh->b_private = NULL;
		gfs2_log_unlock(sdp);
		brelse(bh);
	} else
		gfs2_log_unlock(sdp);

	lock_buffer(bh);
	clear_buffer_dirty(bh);
	bh->b_bdev = NULL;
	clear_buffer_mapped(bh);
	clear_buffer_req(bh);
	clear_buffer_new(bh);
	clear_buffer_delay(bh);
	unlock_buffer(bh);
}

static void gfs2_invalidatepage(struct page *page, unsigned long offset)
{
	struct gfs2_sbd *sdp = page->mapping->host->i_sb->s_fs_info;
	struct buffer_head *head, *bh, *next;
	unsigned int curr_off = 0;

	BUG_ON(!PageLocked(page));
	if (!page_has_buffers(page))
		return;

	bh = head = page_buffers(page);
	do {
		unsigned int next_off = curr_off + bh->b_size;
		next = bh->b_this_page;

		if (offset <= curr_off)
			discard_buffer(sdp, bh);

		curr_off = next_off;
		bh = next;
	} while (bh != head);

	if (!offset)
		try_to_release_page(page, 0);

	return;
}

static ssize_t gfs2_direct_IO_write(struct kiocb *iocb, const struct iovec *iov,
				    loff_t offset, unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct gfs2_holder gh;
	int rv;

	/*
	 * Shared lock, even though its write, since we do no allocation
	 * on this path. All we need change is atime.
	 */
	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
	rv = gfs2_glock_nq_m_atime(1, &gh);
	if (rv)
		goto out;

	/*
	 * Should we return an error here? I can't see that O_DIRECT for
	 * a journaled file makes any sense. For now we'll silently fall
	 * back to buffered I/O, likewise we do the same for stuffed
	 * files since they are (a) small and (b) unaligned.
	 */
	if (gfs2_is_jdata(ip))
		goto out;

	if (gfs2_is_stuffed(ip))
		goto out;

	rv = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
				  iov, offset, nr_segs, gfs2_get_block,
				  NULL, DIO_OWN_LOCKING);
out:
	gfs2_glock_dq_m(1, &gh);
	gfs2_holder_uninit(&gh);

	return rv;
}

/**
 * gfs2_direct_IO
 *
 * This is called with a shared lock already held for the read path.
 * Currently, no locks are held when the write path is called.
 */
static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
			      const struct iovec *iov, loff_t offset,
			      unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct gfs2_sbd *sdp = ip->i_sbd;

	if (rw == WRITE)
		return gfs2_direct_IO_write(iocb, iov, offset, nr_segs);

	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
	    gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
		return -EINVAL;

	return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
			 	    offset, nr_segs, gfs2_get_block, NULL,
				    DIO_OWN_LOCKING);
}

struct address_space_operations gfs2_file_aops = {
	.writepage = gfs2_writepage,
	.readpage = gfs2_readpage,
	.sync_page = block_sync_page,
	.prepare_write = gfs2_prepare_write,
	.commit_write = gfs2_commit_write,
	.bmap = gfs2_bmap,
	.invalidatepage = gfs2_invalidatepage,
	.direct_IO = gfs2_direct_IO,
};