blob: 8f4467a930a548648c33b5cf075a4b022989fd31 [file] [log] [blame]
Mark Fashehccd979b2005-12-15 14:31:24 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 */
21
22#include <linux/fs.h>
23#include <linux/slab.h>
24#include <linux/highmem.h>
25#include <linux/pagemap.h>
26#include <asm/byteorder.h>
27
28#define MLOG_MASK_PREFIX ML_FILE_IO
29#include <cluster/masklog.h>
30
31#include "ocfs2.h"
32
33#include "alloc.h"
34#include "aops.h"
35#include "dlmglue.h"
36#include "extent_map.h"
37#include "file.h"
38#include "inode.h"
39#include "journal.h"
40#include "super.h"
41#include "symlink.h"
42
43#include "buffer_head_io.h"
44
45static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
46 struct buffer_head *bh_result, int create)
47{
48 int err = -EIO;
49 int status;
50 struct ocfs2_dinode *fe = NULL;
51 struct buffer_head *bh = NULL;
52 struct buffer_head *buffer_cache_bh = NULL;
53 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
54 void *kaddr;
55
56 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
57 (unsigned long long)iblock, bh_result, create);
58
59 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
60
61 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
62 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
63 (unsigned long long)iblock);
64 goto bail;
65 }
66
67 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
68 OCFS2_I(inode)->ip_blkno,
69 &bh, OCFS2_BH_CACHED, inode);
70 if (status < 0) {
71 mlog_errno(status);
72 goto bail;
73 }
74 fe = (struct ocfs2_dinode *) bh->b_data;
75
76 if (!OCFS2_IS_VALID_DINODE(fe)) {
77 mlog(ML_ERROR, "Invalid dinode #%"MLFu64": signature = %.*s\n",
78 fe->i_blkno, 7, fe->i_signature);
79 goto bail;
80 }
81
82 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
83 le32_to_cpu(fe->i_clusters))) {
84 mlog(ML_ERROR, "block offset is outside the allocated size: "
85 "%llu\n", (unsigned long long)iblock);
86 goto bail;
87 }
88
89 /* We don't use the page cache to create symlink data, so if
90 * need be, copy it over from the buffer cache. */
91 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
92 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
93 iblock;
94 buffer_cache_bh = sb_getblk(osb->sb, blkno);
95 if (!buffer_cache_bh) {
96 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
97 goto bail;
98 }
99
100 /* we haven't locked out transactions, so a commit
101 * could've happened. Since we've got a reference on
102 * the bh, even if it commits while we're doing the
103 * copy, the data is still good. */
104 if (buffer_jbd(buffer_cache_bh)
105 && ocfs2_inode_is_new(inode)) {
106 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
107 if (!kaddr) {
108 mlog(ML_ERROR, "couldn't kmap!\n");
109 goto bail;
110 }
111 memcpy(kaddr + (bh_result->b_size * iblock),
112 buffer_cache_bh->b_data,
113 bh_result->b_size);
114 kunmap_atomic(kaddr, KM_USER0);
115 set_buffer_uptodate(bh_result);
116 }
117 brelse(buffer_cache_bh);
118 }
119
120 map_bh(bh_result, inode->i_sb,
121 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
122
123 err = 0;
124
125bail:
126 if (bh)
127 brelse(bh);
128
129 mlog_exit(err);
130 return err;
131}
132
133static int ocfs2_get_block(struct inode *inode, sector_t iblock,
134 struct buffer_head *bh_result, int create)
135{
136 int err = 0;
137 u64 p_blkno, past_eof;
138
139 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
140 (unsigned long long)iblock, bh_result, create);
141
142 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
143 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
144 inode, inode->i_ino);
145
146 if (S_ISLNK(inode->i_mode)) {
147 /* this always does I/O for some reason. */
148 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
149 goto bail;
150 }
151
152 /* this can happen if another node truncs after our extend! */
153 spin_lock(&OCFS2_I(inode)->ip_lock);
154 if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
155 OCFS2_I(inode)->ip_clusters))
156 err = -EIO;
157 spin_unlock(&OCFS2_I(inode)->ip_lock);
158 if (err)
159 goto bail;
160
161 err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
162 NULL);
163 if (err) {
164 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
165 "%"MLFu64", NULL)\n", err, inode,
166 (unsigned long long)iblock, p_blkno);
167 goto bail;
168 }
169
170 map_bh(bh_result, inode->i_sb, p_blkno);
171
172 if (bh_result->b_blocknr == 0) {
173 err = -EIO;
174 mlog(ML_ERROR, "iblock = %llu p_blkno = %"MLFu64" "
175 "blkno=(%"MLFu64")\n", (unsigned long long)iblock,
176 p_blkno, OCFS2_I(inode)->ip_blkno);
177 }
178
179 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
180 mlog(0, "Inode %lu, past_eof = %"MLFu64"\n", inode->i_ino, past_eof);
181
182 if (create && (iblock >= past_eof))
183 set_buffer_new(bh_result);
184
185bail:
186 if (err < 0)
187 err = -EIO;
188
189 mlog_exit(err);
190 return err;
191}
192
193static int ocfs2_readpage(struct file *file, struct page *page)
194{
195 struct inode *inode = page->mapping->host;
196 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
197 int ret, unlock = 1;
198
199 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
200
201 ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
202 if (ret != 0) {
203 if (ret == AOP_TRUNCATED_PAGE)
204 unlock = 0;
205 mlog_errno(ret);
206 goto out;
207 }
208
209 down_read(&OCFS2_I(inode)->ip_alloc_sem);
210
211 /*
212 * i_size might have just been updated as we grabed the meta lock. We
213 * might now be discovering a truncate that hit on another node.
214 * block_read_full_page->get_block freaks out if it is asked to read
215 * beyond the end of a file, so we check here. Callers
216 * (generic_file_read, fault->nopage) are clever enough to check i_size
217 * and notice that the page they just read isn't needed.
218 *
219 * XXX sys_readahead() seems to get that wrong?
220 */
221 if (start >= i_size_read(inode)) {
222 char *addr = kmap(page);
223 memset(addr, 0, PAGE_SIZE);
224 flush_dcache_page(page);
225 kunmap(page);
226 SetPageUptodate(page);
227 ret = 0;
228 goto out_alloc;
229 }
230
231 ret = ocfs2_data_lock_with_page(inode, 0, page);
232 if (ret != 0) {
233 if (ret == AOP_TRUNCATED_PAGE)
234 unlock = 0;
235 mlog_errno(ret);
236 goto out_alloc;
237 }
238
239 ret = block_read_full_page(page, ocfs2_get_block);
240 unlock = 0;
241
242 ocfs2_data_unlock(inode, 0);
243out_alloc:
244 up_read(&OCFS2_I(inode)->ip_alloc_sem);
245 ocfs2_meta_unlock(inode, 0);
246out:
247 if (unlock)
248 unlock_page(page);
249 mlog_exit(ret);
250 return ret;
251}
252
253/* Note: Because we don't support holes, our allocation has
254 * already happened (allocation writes zeros to the file data)
255 * so we don't have to worry about ordered writes in
256 * ocfs2_writepage.
257 *
258 * ->writepage is called during the process of invalidating the page cache
259 * during blocked lock processing. It can't block on any cluster locks
260 * to during block mapping. It's relying on the fact that the block
261 * mapping can't have disappeared under the dirty pages that it is
262 * being asked to write back.
263 */
264static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
265{
266 int ret;
267
268 mlog_entry("(0x%p)\n", page);
269
270 ret = block_write_full_page(page, ocfs2_get_block, wbc);
271
272 mlog_exit(ret);
273
274 return ret;
275}
276
277/*
278 * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
279 * from loopback. It must be able to perform its own locking around
280 * ocfs2_get_block().
281 */
282int ocfs2_prepare_write(struct file *file, struct page *page,
283 unsigned from, unsigned to)
284{
285 struct inode *inode = page->mapping->host;
286 int ret;
287
288 mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
289
290 ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
291 if (ret != 0) {
292 mlog_errno(ret);
293 goto out;
294 }
295
296 down_read(&OCFS2_I(inode)->ip_alloc_sem);
297
298 ret = block_prepare_write(page, from, to, ocfs2_get_block);
299
300 up_read(&OCFS2_I(inode)->ip_alloc_sem);
301
302 ocfs2_meta_unlock(inode, 0);
303out:
304 mlog_exit(ret);
305 return ret;
306}
307
308/* Taken from ext3. We don't necessarily need the full blown
309 * functionality yet, but IMHO it's better to cut and paste the whole
310 * thing so we can avoid introducing our own bugs (and easily pick up
311 * their fixes when they happen) --Mark */
312static int walk_page_buffers( handle_t *handle,
313 struct buffer_head *head,
314 unsigned from,
315 unsigned to,
316 int *partial,
317 int (*fn)( handle_t *handle,
318 struct buffer_head *bh))
319{
320 struct buffer_head *bh;
321 unsigned block_start, block_end;
322 unsigned blocksize = head->b_size;
323 int err, ret = 0;
324 struct buffer_head *next;
325
326 for ( bh = head, block_start = 0;
327 ret == 0 && (bh != head || !block_start);
328 block_start = block_end, bh = next)
329 {
330 next = bh->b_this_page;
331 block_end = block_start + blocksize;
332 if (block_end <= from || block_start >= to) {
333 if (partial && !buffer_uptodate(bh))
334 *partial = 1;
335 continue;
336 }
337 err = (*fn)(handle, bh);
338 if (!ret)
339 ret = err;
340 }
341 return ret;
342}
343
344struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
345 struct page *page,
346 unsigned from,
347 unsigned to)
348{
349 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
350 struct ocfs2_journal_handle *handle = NULL;
351 int ret = 0;
352
353 handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
354 if (!handle) {
355 ret = -ENOMEM;
356 mlog_errno(ret);
357 goto out;
358 }
359
360 if (ocfs2_should_order_data(inode)) {
361 ret = walk_page_buffers(handle->k_handle,
362 page_buffers(page),
363 from, to, NULL,
364 ocfs2_journal_dirty_data);
365 if (ret < 0)
366 mlog_errno(ret);
367 }
368out:
369 if (ret) {
370 if (handle)
371 ocfs2_commit_trans(handle);
372 handle = ERR_PTR(ret);
373 }
374 return handle;
375}
376
377static int ocfs2_commit_write(struct file *file, struct page *page,
378 unsigned from, unsigned to)
379{
380 int ret, extending = 0, locklevel = 0;
381 loff_t new_i_size;
382 struct buffer_head *di_bh = NULL;
383 struct inode *inode = page->mapping->host;
384 struct ocfs2_journal_handle *handle = NULL;
385
386 mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
387
388 /* NOTE: ocfs2_file_aio_write has ensured that it's safe for
389 * us to sample inode->i_size here without the metadata lock:
390 *
391 * 1) We're currently holding the inode alloc lock, so no
392 * nodes can change it underneath us.
393 *
394 * 2) We've had to take the metadata lock at least once
395 * already to check for extending writes, hence insuring
396 * that our current copy is also up to date.
397 */
398 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
399 if (new_i_size > i_size_read(inode)) {
400 extending = 1;
401 locklevel = 1;
402 }
403
404 ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
405 if (ret != 0) {
406 mlog_errno(ret);
407 goto out;
408 }
409
410 ret = ocfs2_data_lock_with_page(inode, 1, page);
411 if (ret != 0) {
412 mlog_errno(ret);
413 goto out_unlock_meta;
414 }
415
416 if (extending) {
417 handle = ocfs2_start_walk_page_trans(inode, page, from, to);
418 if (IS_ERR(handle)) {
419 ret = PTR_ERR(handle);
420 handle = NULL;
421 goto out_unlock_data;
422 }
423
424 /* Mark our buffer early. We'd rather catch this error up here
425 * as opposed to after a successful commit_write which would
426 * require us to set back inode->i_size. */
427 ret = ocfs2_journal_access(handle, inode, di_bh,
428 OCFS2_JOURNAL_ACCESS_WRITE);
429 if (ret < 0) {
430 mlog_errno(ret);
431 goto out_commit;
432 }
433 }
434
435 /* might update i_size */
436 ret = generic_commit_write(file, page, from, to);
437 if (ret < 0) {
438 mlog_errno(ret);
439 goto out_commit;
440 }
441
442 if (extending) {
443 loff_t size = (u64) i_size_read(inode);
444 struct ocfs2_dinode *di =
445 (struct ocfs2_dinode *)di_bh->b_data;
446
447 /* ocfs2_mark_inode_dirty is too heavy to use here. */
448 inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
449 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
450
451 di->i_size = cpu_to_le64(size);
452 di->i_ctime = di->i_mtime =
453 cpu_to_le64(inode->i_mtime.tv_sec);
454 di->i_ctime_nsec = di->i_mtime_nsec =
455 cpu_to_le32(inode->i_mtime.tv_nsec);
456
457 ret = ocfs2_journal_dirty(handle, di_bh);
458 if (ret < 0) {
459 mlog_errno(ret);
460 goto out_commit;
461 }
462 }
463
464 BUG_ON(extending && (i_size_read(inode) != new_i_size));
465
466out_commit:
467 if (handle)
468 ocfs2_commit_trans(handle);
469out_unlock_data:
470 ocfs2_data_unlock(inode, 1);
471out_unlock_meta:
472 ocfs2_meta_unlock(inode, locklevel);
473out:
474 if (di_bh)
475 brelse(di_bh);
476
477 mlog_exit(ret);
478 return ret;
479}
480
481static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
482{
483 sector_t status;
484 u64 p_blkno = 0;
485 int err = 0;
486 struct inode *inode = mapping->host;
487
488 mlog_entry("(block = %llu)\n", (unsigned long long)block);
489
490 /* We don't need to lock journal system files, since they aren't
491 * accessed concurrently from multiple nodes.
492 */
493 if (!INODE_JOURNAL(inode)) {
494 err = ocfs2_meta_lock(inode, NULL, NULL, 0);
495 if (err) {
496 if (err != -ENOENT)
497 mlog_errno(err);
498 goto bail;
499 }
500 down_read(&OCFS2_I(inode)->ip_alloc_sem);
501 }
502
503 err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
504 NULL);
505
506 if (!INODE_JOURNAL(inode)) {
507 up_read(&OCFS2_I(inode)->ip_alloc_sem);
508 ocfs2_meta_unlock(inode, 0);
509 }
510
511 if (err) {
512 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
513 (unsigned long long)block);
514 mlog_errno(err);
515 goto bail;
516 }
517
518
519bail:
520 status = err ? 0 : p_blkno;
521
522 mlog_exit((int)status);
523
524 return status;
525}
526
527/*
528 * TODO: Make this into a generic get_blocks function.
529 *
530 * From do_direct_io in direct-io.c:
531 * "So what we do is to permit the ->get_blocks function to populate
532 * bh.b_size with the size of IO which is permitted at this offset and
533 * this i_blkbits."
534 *
535 * This function is called directly from get_more_blocks in direct-io.c.
536 *
537 * called like this: dio->get_blocks(dio->inode, fs_startblk,
538 * fs_count, map_bh, dio->rw == WRITE);
539 */
540static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
541 unsigned long max_blocks,
542 struct buffer_head *bh_result, int create)
543{
544 int ret;
545 u64 vbo_max; /* file offset, max_blocks from iblock */
546 u64 p_blkno;
547 int contig_blocks;
548 unsigned char blocksize_bits;
549
550 if (!inode || !bh_result) {
551 mlog(ML_ERROR, "inode or bh_result is null\n");
552 return -EIO;
553 }
554
555 blocksize_bits = inode->i_sb->s_blocksize_bits;
556
557 /* This function won't even be called if the request isn't all
558 * nicely aligned and of the right size, so there's no need
559 * for us to check any of that. */
560
561 vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;
562
563 spin_lock(&OCFS2_I(inode)->ip_lock);
564 if ((iblock + max_blocks) >
565 ocfs2_clusters_to_blocks(inode->i_sb,
566 OCFS2_I(inode)->ip_clusters)) {
567 spin_unlock(&OCFS2_I(inode)->ip_lock);
568 ret = -EIO;
569 goto bail;
570 }
571 spin_unlock(&OCFS2_I(inode)->ip_lock);
572
573 /* This figures out the size of the next contiguous block, and
574 * our logical offset */
575 ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
576 &contig_blocks);
577 if (ret) {
578 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
579 (unsigned long long)iblock);
580 ret = -EIO;
581 goto bail;
582 }
583
584 map_bh(bh_result, inode->i_sb, p_blkno);
585
586 /* make sure we don't map more than max_blocks blocks here as
587 that's all the kernel will handle at this point. */
588 if (max_blocks < contig_blocks)
589 contig_blocks = max_blocks;
590 bh_result->b_size = contig_blocks << blocksize_bits;
591bail:
592 return ret;
593}
594
595/*
596 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
597 * particularly interested in the aio/dio case. Like the core uses
598 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
599 * truncation on another.
600 */
601static void ocfs2_dio_end_io(struct kiocb *iocb,
602 loff_t offset,
603 ssize_t bytes,
604 void *private)
605{
606 struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
607
608 /* this io's submitter should not have unlocked this before we could */
609 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
610 ocfs2_iocb_clear_rw_locked(iocb);
611 up_read(&inode->i_alloc_sem);
612 ocfs2_rw_unlock(inode, 0);
613}
614
615static ssize_t ocfs2_direct_IO(int rw,
616 struct kiocb *iocb,
617 const struct iovec *iov,
618 loff_t offset,
619 unsigned long nr_segs)
620{
621 struct file *file = iocb->ki_filp;
622 struct inode *inode = file->f_dentry->d_inode->i_mapping->host;
623 int ret;
624
625 mlog_entry_void();
626 ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
627 inode->i_sb->s_bdev, iov, offset,
628 nr_segs,
629 ocfs2_direct_IO_get_blocks,
630 ocfs2_dio_end_io);
631 mlog_exit(ret);
632 return ret;
633}
634
635struct address_space_operations ocfs2_aops = {
636 .readpage = ocfs2_readpage,
637 .writepage = ocfs2_writepage,
638 .prepare_write = ocfs2_prepare_write,
639 .commit_write = ocfs2_commit_write,
640 .bmap = ocfs2_bmap,
641 .sync_page = block_sync_page,
642 .direct_IO = ocfs2_direct_IO
643};