blob: 27563816e1c5a0f086657b12b0fab0cbc861fbef [file] [log] [blame]
David Teiglandb3b94fa2006-01-16 16:50:04 +00001/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
Bob Peterson7eabb772008-01-28 11:24:35 -06003 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
David Teiglandb3b94fa2006-01-16 16:50:04 +00004 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
Steven Whitehousee9fc2aa2006-09-01 11:05:15 -04007 * of the GNU General Public License version 2.
David Teiglandb3b94fa2006-01-16 16:50:04 +00008 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/pagemap.h>
Steven Whitehousefd88de562006-05-05 16:59:11 -040016#include <linux/pagevec.h>
Steven Whitehouse9b124fb2006-01-30 11:55:32 +000017#include <linux/mpage.h>
Steven Whitehoused1665e42006-02-14 11:54:42 +000018#include <linux/fs.h>
Steven Whitehousea8d638e2007-01-15 13:52:17 +000019#include <linux/writeback.h>
Steven Whitehouse7765ec22007-10-16 01:25:07 -070020#include <linux/swap.h>
Steven Whitehouse5c676f62006-02-27 17:23:27 -050021#include <linux/gfs2_ondisk.h>
Fabio Massimo Di Nitto7d308592006-09-19 07:56:29 +020022#include <linux/lm_interface.h>
Steven Whitehouse47e83b52007-10-18 11:15:50 +010023#include <linux/backing-dev.h>
David Teiglandb3b94fa2006-01-16 16:50:04 +000024
25#include "gfs2.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050026#include "incore.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000027#include "bmap.h"
28#include "glock.h"
29#include "inode.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000030#include "log.h"
31#include "meta_io.h"
32#include "ops_address.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000033#include "quota.h"
34#include "trans.h"
Steven Whitehouse18ec7d52006-02-08 11:50:51 +000035#include "rgrp.h"
Robert Petersoncd81a4b2007-05-14 12:42:18 -050036#include "super.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050037#include "util.h"
Steven Whitehouse4340fe62006-07-11 09:46:33 -040038#include "glops.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000039
Steven Whitehouseba7f7292006-07-26 11:27:10 -040040
41static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
42 unsigned int from, unsigned int to)
43{
44 struct buffer_head *head = page_buffers(page);
45 unsigned int bsize = head->b_size;
46 struct buffer_head *bh;
47 unsigned int start, end;
48
49 for (bh = head, start = 0; bh != head || !start;
50 bh = bh->b_this_page, start = end) {
51 end = start + bsize;
52 if (end <= from || start >= to)
53 continue;
Benjamin Marzinskiddf4b422007-06-01 14:21:38 -050054 if (gfs2_is_jdata(ip))
55 set_buffer_uptodate(bh);
Steven Whitehouseba7f7292006-07-26 11:27:10 -040056 gfs2_trans_add_bh(ip->i_gl, bh, 0);
57 }
58}
59
David Teiglandb3b94fa2006-01-16 16:50:04 +000060/**
Steven Whitehouse7a6bbac2006-09-18 17:18:23 -040061 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
David Teiglandb3b94fa2006-01-16 16:50:04 +000062 * @inode: The inode
63 * @lblock: The block number to look up
64 * @bh_result: The buffer head to return the result in
65 * @create: Non-zero if we may add block to the file
66 *
67 * Returns: errno
68 */
69
Steven Whitehouse7a6bbac2006-09-18 17:18:23 -040070static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
71 struct buffer_head *bh_result, int create)
David Teiglandb3b94fa2006-01-16 16:50:04 +000072{
David Teiglandb3b94fa2006-01-16 16:50:04 +000073 int error;
74
Bob Petersone9e1ef22007-12-10 14:13:27 -060075 error = gfs2_block_map(inode, lblock, bh_result, 0);
David Teiglandb3b94fa2006-01-16 16:50:04 +000076 if (error)
77 return error;
Wendy Chengde986e82007-09-18 09:19:13 -040078 if (!buffer_mapped(bh_result))
Steven Whitehouse7a6bbac2006-09-18 17:18:23 -040079 return -EIO;
Steven Whitehouse623d9352006-08-31 12:14:44 -040080 return 0;
81}
Steven Whitehouse7a6bbac2006-09-18 17:18:23 -040082
83static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
84 struct buffer_head *bh_result, int create)
85{
Bob Petersone9e1ef22007-12-10 14:13:27 -060086 return gfs2_block_map(inode, lblock, bh_result, 0);
Steven Whitehouse7a6bbac2006-09-18 17:18:23 -040087}
88
David Teiglandb3b94fa2006-01-16 16:50:04 +000089/**
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +010090 * gfs2_writepage_common - Common bits of writepage
91 * @page: The page to be written
92 * @wbc: The writeback control
David Teiglandb3b94fa2006-01-16 16:50:04 +000093 *
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +010094 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
David Teiglandb3b94fa2006-01-16 16:50:04 +000095 */
96
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +010097static int gfs2_writepage_common(struct page *page,
98 struct writeback_control *wbc)
David Teiglandb3b94fa2006-01-16 16:50:04 +000099{
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000100 struct inode *inode = page->mapping->host;
Steven Whitehousef4387142006-08-08 13:23:19 -0400101 struct gfs2_inode *ip = GFS2_I(inode);
102 struct gfs2_sbd *sdp = GFS2_SB(inode);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000103 loff_t i_size = i_size_read(inode);
104 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
105 unsigned offset;
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +0100106
107 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
108 goto out;
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +0100109 if (current->journal_info)
110 goto redirty;
111 /* Is the page fully outside i_size? (truncate in progress) */
112 offset = i_size & (PAGE_CACHE_SIZE-1);
113 if (page->index > end_index || (page->index == end_index && !offset)) {
114 page->mapping->a_ops->invalidatepage(page, 0);
115 goto out;
116 }
117 return 1;
118redirty:
119 redirty_page_for_writepage(wbc, page);
120out:
121 unlock_page(page);
122 return 0;
123}
124
125/**
126 * gfs2_writeback_writepage - Write page for writeback mappings
127 * @page: The page
128 * @wbc: The writeback control
129 *
130 */
131
132static int gfs2_writeback_writepage(struct page *page,
133 struct writeback_control *wbc)
134{
135 int ret;
136
137 ret = gfs2_writepage_common(page, wbc);
138 if (ret <= 0)
139 return ret;
140
141 ret = mpage_writepage(page, gfs2_get_block_noalloc, wbc);
142 if (ret == -EAGAIN)
143 ret = block_write_full_page(page, gfs2_get_block_noalloc, wbc);
144 return ret;
145}
146
147/**
148 * gfs2_ordered_writepage - Write page for ordered data files
149 * @page: The page to write
150 * @wbc: The writeback control
151 *
152 */
153
154static int gfs2_ordered_writepage(struct page *page,
155 struct writeback_control *wbc)
156{
157 struct inode *inode = page->mapping->host;
158 struct gfs2_inode *ip = GFS2_I(inode);
159 int ret;
160
161 ret = gfs2_writepage_common(page, wbc);
162 if (ret <= 0)
163 return ret;
164
165 if (!page_has_buffers(page)) {
166 create_empty_buffers(page, inode->i_sb->s_blocksize,
167 (1 << BH_Dirty)|(1 << BH_Uptodate));
168 }
169 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1);
170 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
171}
172
173/**
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +0100174 * __gfs2_jdata_writepage - The core of jdata writepage
175 * @page: The page to write
176 * @wbc: The writeback control
177 *
178 * This is shared between writepage and writepages and implements the
179 * core of the writepage operation. If a transaction is required then
180 * PageChecked will have been set and the transaction will have
181 * already been started before this is called.
182 */
183
184static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
185{
186 struct inode *inode = page->mapping->host;
187 struct gfs2_inode *ip = GFS2_I(inode);
188 struct gfs2_sbd *sdp = GFS2_SB(inode);
189
190 if (PageChecked(page)) {
191 ClearPageChecked(page);
192 if (!page_has_buffers(page)) {
193 create_empty_buffers(page, inode->i_sb->s_blocksize,
194 (1 << BH_Dirty)|(1 << BH_Uptodate));
195 }
196 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
197 }
198 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
199}
200
201/**
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +0100202 * gfs2_jdata_writepage - Write complete page
203 * @page: Page to write
204 *
205 * Returns: errno
206 *
207 */
208
209static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
210{
211 struct inode *inode = page->mapping->host;
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +0100212 struct gfs2_sbd *sdp = GFS2_SB(inode);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000213 int error;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000214 int done_trans = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000215
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +0100216 error = gfs2_writepage_common(page, wbc);
217 if (error <= 0)
218 return error;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000219
Steven Whitehousebf36a712007-10-17 08:35:19 +0100220 if (PageChecked(page)) {
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +0100221 if (wbc->sync_mode != WB_SYNC_ALL)
222 goto out_ignore;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000223 error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
224 if (error)
225 goto out_ignore;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000226 done_trans = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000227 }
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +0100228 error = __gfs2_jdata_writepage(page, wbc);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000229 if (done_trans)
230 gfs2_trans_end(sdp);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000231 return error;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000232
233out_ignore:
234 redirty_page_for_writepage(wbc, page);
235 unlock_page(page);
236 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000237}
238
239/**
Steven Whitehouse55610932007-10-17 08:47:38 +0100240 * gfs2_writeback_writepages - Write a bunch of dirty pages back to disk
Steven Whitehousea8d638e2007-01-15 13:52:17 +0000241 * @mapping: The mapping to write
242 * @wbc: Write-back control
243 *
Steven Whitehouse55610932007-10-17 08:47:38 +0100244 * For the data=writeback case we can already ignore buffer heads
Steven Whitehousea8d638e2007-01-15 13:52:17 +0000245 * and write whole extents at once. This is a big reduction in the
246 * number of I/O requests we send and the bmap calls we make in this case.
247 */
Steven Whitehouse55610932007-10-17 08:47:38 +0100248static int gfs2_writeback_writepages(struct address_space *mapping,
249 struct writeback_control *wbc)
Steven Whitehousea8d638e2007-01-15 13:52:17 +0000250{
Steven Whitehouse55610932007-10-17 08:47:38 +0100251 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
Steven Whitehousea8d638e2007-01-15 13:52:17 +0000252}
253
254/**
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +0100255 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
256 * @mapping: The mapping
257 * @wbc: The writeback control
258 * @writepage: The writepage function to call for each page
259 * @pvec: The vector of pages
260 * @nr_pages: The number of pages to write
261 *
262 * Returns: non-zero if loop should terminate, zero otherwise
263 */
264
265static int gfs2_write_jdata_pagevec(struct address_space *mapping,
266 struct writeback_control *wbc,
267 struct pagevec *pvec,
268 int nr_pages, pgoff_t end)
269{
270 struct inode *inode = mapping->host;
271 struct gfs2_sbd *sdp = GFS2_SB(inode);
272 loff_t i_size = i_size_read(inode);
273 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
274 unsigned offset = i_size & (PAGE_CACHE_SIZE-1);
275 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
276 struct backing_dev_info *bdi = mapping->backing_dev_info;
277 int i;
278 int ret;
279
Abhijith Das20b95bf2008-03-06 17:43:52 -0600280 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +0100281 if (ret < 0)
282 return ret;
283
284 for(i = 0; i < nr_pages; i++) {
285 struct page *page = pvec->pages[i];
286
287 lock_page(page);
288
289 if (unlikely(page->mapping != mapping)) {
290 unlock_page(page);
291 continue;
292 }
293
294 if (!wbc->range_cyclic && page->index > end) {
295 ret = 1;
296 unlock_page(page);
297 continue;
298 }
299
300 if (wbc->sync_mode != WB_SYNC_NONE)
301 wait_on_page_writeback(page);
302
303 if (PageWriteback(page) ||
304 !clear_page_dirty_for_io(page)) {
305 unlock_page(page);
306 continue;
307 }
308
309 /* Is the page fully outside i_size? (truncate in progress) */
310 if (page->index > end_index || (page->index == end_index && !offset)) {
311 page->mapping->a_ops->invalidatepage(page, 0);
312 unlock_page(page);
313 continue;
314 }
315
316 ret = __gfs2_jdata_writepage(page, wbc);
317
318 if (ret || (--(wbc->nr_to_write) <= 0))
319 ret = 1;
320 if (wbc->nonblocking && bdi_write_congested(bdi)) {
321 wbc->encountered_congestion = 1;
322 ret = 1;
323 }
324
325 }
326 gfs2_trans_end(sdp);
327 return ret;
328}
329
330/**
331 * gfs2_write_cache_jdata - Like write_cache_pages but different
332 * @mapping: The mapping to write
333 * @wbc: The writeback control
334 * @writepage: The writepage function to call
335 * @data: The data to pass to writepage
336 *
337 * The reason that we use our own function here is that we need to
338 * start transactions before we grab page locks. This allows us
339 * to get the ordering right.
340 */
341
342static int gfs2_write_cache_jdata(struct address_space *mapping,
343 struct writeback_control *wbc)
344{
345 struct backing_dev_info *bdi = mapping->backing_dev_info;
346 int ret = 0;
347 int done = 0;
348 struct pagevec pvec;
349 int nr_pages;
350 pgoff_t index;
351 pgoff_t end;
352 int scanned = 0;
353 int range_whole = 0;
354
355 if (wbc->nonblocking && bdi_write_congested(bdi)) {
356 wbc->encountered_congestion = 1;
357 return 0;
358 }
359
360 pagevec_init(&pvec, 0);
361 if (wbc->range_cyclic) {
362 index = mapping->writeback_index; /* Start from prev offset */
363 end = -1;
364 } else {
365 index = wbc->range_start >> PAGE_CACHE_SHIFT;
366 end = wbc->range_end >> PAGE_CACHE_SHIFT;
367 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
368 range_whole = 1;
369 scanned = 1;
370 }
371
372retry:
373 while (!done && (index <= end) &&
374 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
375 PAGECACHE_TAG_DIRTY,
376 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
377 scanned = 1;
378 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end);
379 if (ret)
380 done = 1;
381 if (ret > 0)
382 ret = 0;
383
384 pagevec_release(&pvec);
385 cond_resched();
386 }
387
388 if (!scanned && !done) {
389 /*
390 * We hit the last page and there is more work to be done: wrap
391 * back to the start of the file
392 */
393 scanned = 1;
394 index = 0;
395 goto retry;
396 }
397
398 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
399 mapping->writeback_index = index;
400 return ret;
401}
402
403
404/**
405 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
406 * @mapping: The mapping to write
407 * @wbc: The writeback control
408 *
409 */
410
411static int gfs2_jdata_writepages(struct address_space *mapping,
412 struct writeback_control *wbc)
413{
414 struct gfs2_inode *ip = GFS2_I(mapping->host);
415 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
416 int ret;
417
418 ret = gfs2_write_cache_jdata(mapping, wbc);
419 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
420 gfs2_log_flush(sdp, ip->i_gl);
421 ret = gfs2_write_cache_jdata(mapping, wbc);
422 }
423 return ret;
424}
425
426/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000427 * stuffed_readpage - Fill in a Linux page with stuffed file data
428 * @ip: the inode
429 * @page: the page
430 *
431 * Returns: errno
432 */
433
434static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
435{
436 struct buffer_head *dibh;
437 void *kaddr;
438 int error;
439
Steven Whitehousebf126ae2007-04-20 09:18:30 +0100440 /*
Nick Piggin3c18ddd2008-04-28 02:12:10 -0700441 * Due to the order of unstuffing files and ->fault(), we can be
Steven Whitehousebf126ae2007-04-20 09:18:30 +0100442 * asked for a zero page in the case of a stuffed file being extended,
443 * so we need to supply one here. It doesn't happen often.
444 */
445 if (unlikely(page->index)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800446 zero_user(page, 0, PAGE_CACHE_SIZE);
Steven Whitehousebf126ae2007-04-20 09:18:30 +0100447 return 0;
448 }
Steven Whitehousefd88de562006-05-05 16:59:11 -0400449
David Teiglandb3b94fa2006-01-16 16:50:04 +0000450 error = gfs2_meta_inode_buffer(ip, &dibh);
451 if (error)
452 return error;
453
Steven Whitehouse5c4e9e02006-02-15 12:26:19 +0000454 kaddr = kmap_atomic(page, KM_USER0);
Steven Whitehousefd88de562006-05-05 16:59:11 -0400455 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
David Teiglandb3b94fa2006-01-16 16:50:04 +0000456 ip->i_di.di_size);
Steven Whitehousefd88de562006-05-05 16:59:11 -0400457 memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
Russell Cattelanc312c4f2006-10-12 09:23:41 -0400458 kunmap_atomic(kaddr, KM_USER0);
Steven Whitehousebf126ae2007-04-20 09:18:30 +0100459 flush_dcache_page(page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000460 brelse(dibh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000461 SetPageUptodate(page);
462
463 return 0;
464}
465
David Teiglandb3b94fa2006-01-16 16:50:04 +0000466
467/**
Steven Whitehouse51ff87b2007-10-15 14:42:35 +0100468 * __gfs2_readpage - readpage
469 * @file: The file to read a page for
David Teiglandb3b94fa2006-01-16 16:50:04 +0000470 * @page: The page to read
471 *
Steven Whitehouse51ff87b2007-10-15 14:42:35 +0100472 * This is the core of gfs2's readpage. Its used by the internal file
473 * reading code as in that case we already hold the glock. Also its
474 * called by gfs2_readpage() once the required lock has been granted.
475 *
476 */
477
478static int __gfs2_readpage(void *file, struct page *page)
479{
480 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
481 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
482 int error;
483
484 if (gfs2_is_stuffed(ip)) {
485 error = stuffed_readpage(ip, page);
486 unlock_page(page);
487 } else {
Bob Petersone9e1ef22007-12-10 14:13:27 -0600488 error = mpage_readpage(page, gfs2_block_map);
Steven Whitehouse51ff87b2007-10-15 14:42:35 +0100489 }
490
491 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
492 return -EIO;
493
494 return error;
495}
496
497/**
498 * gfs2_readpage - read a page of a file
499 * @file: The file to read
500 * @page: The page of the file
501 *
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100502 * This deals with the locking required. We have to unlock and
503 * relock the page in order to get the locking in the right
504 * order.
David Teiglandb3b94fa2006-01-16 16:50:04 +0000505 */
506
507static int gfs2_readpage(struct file *file, struct page *page)
508{
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100509 struct address_space *mapping = page->mapping;
510 struct gfs2_inode *ip = GFS2_I(mapping->host);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100511 struct gfs2_holder gh;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000512 int error;
513
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100514 unlock_page(page);
Steven Whitehouse719ee342008-09-18 13:53:59 +0100515 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
516 error = gfs2_glock_nq(&gh);
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100517 if (unlikely(error))
Steven Whitehouse6802e342008-05-21 17:03:22 +0100518 goto out;
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100519 error = AOP_TRUNCATED_PAGE;
520 lock_page(page);
521 if (page->mapping == mapping && !PageUptodate(page))
522 error = __gfs2_readpage(file, page);
523 else
524 unlock_page(page);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100525 gfs2_glock_dq(&gh);
Steven Whitehouse7afd88d2008-02-22 16:07:18 +0000526out:
Steven Whitehouse6802e342008-05-21 17:03:22 +0100527 gfs2_holder_uninit(&gh);
Steven Whitehouse01b7c7a2008-06-02 09:14:54 +0100528 if (error && error != AOP_TRUNCATED_PAGE)
529 lock_page(page);
Steven Whitehouse51ff87b2007-10-15 14:42:35 +0100530 return error;
531}
532
533/**
534 * gfs2_internal_read - read an internal file
535 * @ip: The gfs2 inode
536 * @ra_state: The readahead state (or NULL for no readahead)
537 * @buf: The buffer to fill
538 * @pos: The file position
539 * @size: The amount to read
540 *
541 */
542
543int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
544 char *buf, loff_t *pos, unsigned size)
545{
546 struct address_space *mapping = ip->i_inode.i_mapping;
547 unsigned long index = *pos / PAGE_CACHE_SIZE;
548 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
549 unsigned copied = 0;
550 unsigned amt;
551 struct page *page;
552 void *p;
553
554 do {
555 amt = size - copied;
556 if (offset + size > PAGE_CACHE_SIZE)
557 amt = PAGE_CACHE_SIZE - offset;
558 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
559 if (IS_ERR(page))
560 return PTR_ERR(page);
561 p = kmap_atomic(page, KM_USER0);
562 memcpy(buf + copied, p + offset, amt);
563 kunmap_atomic(p, KM_USER0);
564 mark_page_accessed(page);
565 page_cache_release(page);
566 copied += amt;
567 index++;
568 offset = 0;
569 } while(copied < size);
570 (*pos) += size;
571 return size;
Steven Whitehousefd88de562006-05-05 16:59:11 -0400572}
573
Steven Whitehousefd88de562006-05-05 16:59:11 -0400574/**
575 * gfs2_readpages - Read a bunch of pages at once
576 *
577 * Some notes:
578 * 1. This is only for readahead, so we can simply ignore any things
579 * which are slightly inconvenient (such as locking conflicts between
580 * the page lock and the glock) and return having done no I/O. Its
581 * obviously not something we'd want to do on too regular a basis.
582 * Any I/O we ignore at this time will be done via readpage later.
Steven Whitehousee1d5b182006-12-15 16:49:51 -0500583 * 2. We don't handle stuffed files here we let readpage do the honours.
Steven Whitehousefd88de562006-05-05 16:59:11 -0400584 * 3. mpage_readpages() does most of the heavy lifting in the common case.
Bob Petersone9e1ef22007-12-10 14:13:27 -0600585 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
Steven Whitehousefd88de562006-05-05 16:59:11 -0400586 */
Steven Whitehouse3cc3f712007-10-15 15:40:33 +0100587
Steven Whitehousefd88de562006-05-05 16:59:11 -0400588static int gfs2_readpages(struct file *file, struct address_space *mapping,
589 struct list_head *pages, unsigned nr_pages)
590{
591 struct inode *inode = mapping->host;
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400592 struct gfs2_inode *ip = GFS2_I(inode);
593 struct gfs2_sbd *sdp = GFS2_SB(inode);
Steven Whitehousefd88de562006-05-05 16:59:11 -0400594 struct gfs2_holder gh;
Steven Whitehouse3cc3f712007-10-15 15:40:33 +0100595 int ret;
Steven Whitehousefd88de562006-05-05 16:59:11 -0400596
Steven Whitehouse719ee342008-09-18 13:53:59 +0100597 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
598 ret = gfs2_glock_nq(&gh);
Steven Whitehouse51ff87b2007-10-15 14:42:35 +0100599 if (unlikely(ret))
Steven Whitehouse3cc3f712007-10-15 15:40:33 +0100600 goto out_uninit;
Steven Whitehousee1d5b182006-12-15 16:49:51 -0500601 if (!gfs2_is_stuffed(ip))
Bob Petersone9e1ef22007-12-10 14:13:27 -0600602 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
Steven Whitehouse3cc3f712007-10-15 15:40:33 +0100603 gfs2_glock_dq(&gh);
604out_uninit:
605 gfs2_holder_uninit(&gh);
Steven Whitehousefd88de562006-05-05 16:59:11 -0400606 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
607 ret = -EIO;
608 return ret;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000609}
610
611/**
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700612 * gfs2_write_begin - Begin to write to a file
David Teiglandb3b94fa2006-01-16 16:50:04 +0000613 * @file: The file to write to
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700614 * @mapping: The mapping in which to write
615 * @pos: The file offset at which to start writing
616 * @len: Length of the write
617 * @flags: Various flags
618 * @pagep: Pointer to return the page
619 * @fsdata: Pointer to return fs data (unused by GFS2)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000620 *
621 * Returns: errno
622 */
623
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700624static int gfs2_write_begin(struct file *file, struct address_space *mapping,
625 loff_t pos, unsigned len, unsigned flags,
626 struct page **pagep, void **fsdata)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000627{
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700628 struct gfs2_inode *ip = GFS2_I(mapping->host);
629 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000630 unsigned int data_blocks, ind_blocks, rblocks;
631 int alloc_required;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000632 int error = 0;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000633 struct gfs2_alloc *al;
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700634 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
635 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
636 unsigned to = from + len;
637 struct page *page;
Russell Cattelan52ae7b72006-10-09 12:11:54 -0500638
Steven Whitehouse719ee342008-09-18 13:53:59 +0100639 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
640 error = gfs2_glock_nq(&ip->i_gh);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700641 if (unlikely(error))
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000642 goto out_uninit;
643
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700644 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700645 error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
646 if (error)
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100647 goto out_unlock;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000648
649 if (alloc_required) {
650 al = gfs2_alloc_get(ip);
Cyrill Gorcunov182fe5a2008-03-03 21:54:21 +0300651 if (!al) {
652 error = -ENOMEM;
653 goto out_unlock;
654 }
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000655
Steven Whitehoused82661d2008-03-10 15:34:50 +0000656 error = gfs2_quota_lock_check(ip);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000657 if (error)
658 goto out_alloc_put;
659
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000660 al->al_requested = data_blocks + ind_blocks;
661 error = gfs2_inplace_reserve(ip);
662 if (error)
663 goto out_qunlock;
664 }
665
666 rblocks = RES_DINODE + ind_blocks;
667 if (gfs2_is_jdata(ip))
668 rblocks += data_blocks ? data_blocks : 1;
669 if (ind_blocks || data_blocks)
670 rblocks += RES_STATFS + RES_QUOTA;
671
Steven Whitehouse16615be2007-09-17 10:59:52 +0100672 error = gfs2_trans_begin(sdp, rblocks,
673 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000674 if (error)
Steven Whitehousea867bb22007-07-17 10:29:02 +0100675 goto out_trans_fail;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000676
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100677 error = -ENOMEM;
678 page = __grab_cache_page(mapping, index);
679 *pagep = page;
680 if (unlikely(!page))
681 goto out_endtrans;
682
David Teiglandb3b94fa2006-01-16 16:50:04 +0000683 if (gfs2_is_stuffed(ip)) {
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100684 error = 0;
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700685 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
Steven Whitehousef25ef0c2006-07-26 10:51:20 -0400686 error = gfs2_unstuff_dinode(ip, page);
Steven Whitehouse5c4e9e02006-02-15 12:26:19 +0000687 if (error == 0)
688 goto prepare_write;
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100689 } else if (!PageUptodate(page)) {
David Teiglandb3b94fa2006-01-16 16:50:04 +0000690 error = stuffed_readpage(ip, page);
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100691 }
Steven Whitehouse5c4e9e02006-02-15 12:26:19 +0000692 goto out;
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000693 }
694
Steven Whitehouse5c4e9e02006-02-15 12:26:19 +0000695prepare_write:
Bob Petersone9e1ef22007-12-10 14:13:27 -0600696 error = block_prepare_write(page, from, to, gfs2_block_map);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000697out:
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100698 if (error == 0)
699 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000700
Steven Whitehousec41d4f02007-10-17 14:05:41 +0100701 page_cache_release(page);
702 if (pos + len > ip->i_inode.i_size)
703 vmtruncate(&ip->i_inode, ip->i_inode.i_size);
704out_endtrans:
705 gfs2_trans_end(sdp);
706out_trans_fail:
707 if (alloc_required) {
708 gfs2_inplace_release(ip);
709out_qunlock:
710 gfs2_quota_unlock(ip);
711out_alloc_put:
712 gfs2_alloc_put(ip);
713 }
714out_unlock:
715 gfs2_glock_dq(&ip->i_gh);
716out_uninit:
717 gfs2_holder_uninit(&ip->i_gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000718 return error;
719}
720
721/**
Robert Peterson7ae8fa82007-05-09 09:37:57 -0500722 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
723 * @inode: the rindex inode
724 */
725static void adjust_fs_space(struct inode *inode)
726{
727 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
728 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
729 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
730 u64 fs_total, new_free;
731
732 /* Total up the file system space, according to the latest rindex. */
733 fs_total = gfs2_ri_total(sdp);
734
735 spin_lock(&sdp->sd_statfs_spin);
736 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
737 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
738 else
739 new_free = 0;
740 spin_unlock(&sdp->sd_statfs_spin);
Robert Peterson6c532672007-05-10 16:54:38 -0500741 fs_warn(sdp, "File system extended by %llu blocks.\n",
742 (unsigned long long)new_free);
Robert Peterson7ae8fa82007-05-09 09:37:57 -0500743 gfs2_statfs_change(sdp, new_free, new_free, 0);
744}
745
746/**
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700747 * gfs2_stuffed_write_end - Write end for stuffed files
748 * @inode: The inode
749 * @dibh: The buffer_head containing the on-disk inode
750 * @pos: The file position
751 * @len: The length of the write
752 * @copied: How much was actually copied by the VFS
753 * @page: The page
754 *
755 * This copies the data from the page into the inode block after
756 * the inode data structure itself.
David Teiglandb3b94fa2006-01-16 16:50:04 +0000757 *
758 * Returns: errno
759 */
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700760static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
761 loff_t pos, unsigned len, unsigned copied,
762 struct page *page)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000763{
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400764 struct gfs2_inode *ip = GFS2_I(inode);
765 struct gfs2_sbd *sdp = GFS2_SB(inode);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700766 u64 to = pos + copied;
767 void *kaddr;
768 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
769 struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000770
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700771 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
772 kaddr = kmap_atomic(page, KM_USER0);
773 memcpy(buf + pos, kaddr + pos, copied);
774 memset(kaddr + pos + copied, 0, len - copied);
775 flush_dcache_page(page);
776 kunmap_atomic(kaddr, KM_USER0);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000777
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700778 if (!PageUptodate(page))
David Teiglandb3b94fa2006-01-16 16:50:04 +0000779 SetPageUptodate(page);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700780 unlock_page(page);
781 page_cache_release(page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000782
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700783 if (inode->i_size < to) {
784 i_size_write(inode, to);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000785 ip->i_di.di_size = inode->i_size;
Steven Whitehouse48516ce2006-10-02 12:39:19 -0400786 di->di_size = cpu_to_be64(inode->i_size);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700787 mark_inode_dirty(inode);
Steven Whitehouse48516ce2006-10-02 12:39:19 -0400788 }
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000789
Robert Peterson7ae8fa82007-05-09 09:37:57 -0500790 if (inode == sdp->sd_rindex)
791 adjust_fs_space(inode);
792
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000793 brelse(dibh);
794 gfs2_trans_end(sdp);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700795 gfs2_glock_dq(&ip->i_gh);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000796 gfs2_holder_uninit(&ip->i_gh);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700797 return copied;
798}
David Teiglandb3b94fa2006-01-16 16:50:04 +0000799
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700800/**
801 * gfs2_write_end
802 * @file: The file to write to
803 * @mapping: The address space to write to
804 * @pos: The file position
805 * @len: The length of the data
806 * @copied:
807 * @page: The page that has been written
808 * @fsdata: The fsdata (unused in GFS2)
809 *
810 * The main write_end function for GFS2. We have a separate one for
811 * stuffed files as they are slightly different, otherwise we just
812 * put our locking around the VFS provided functions.
813 *
814 * Returns: errno
815 */
816
817static int gfs2_write_end(struct file *file, struct address_space *mapping,
818 loff_t pos, unsigned len, unsigned copied,
819 struct page *page, void *fsdata)
820{
821 struct inode *inode = page->mapping->host;
822 struct gfs2_inode *ip = GFS2_I(inode);
823 struct gfs2_sbd *sdp = GFS2_SB(inode);
824 struct buffer_head *dibh;
Steven Whitehouse6dbd8222008-01-10 15:18:55 +0000825 struct gfs2_alloc *al = ip->i_alloc;
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700826 struct gfs2_dinode *di;
827 unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
828 unsigned int to = from + len;
829 int ret;
830
Steven Whitehouse7afd88d2008-02-22 16:07:18 +0000831 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700832
833 ret = gfs2_meta_inode_buffer(ip, &dibh);
834 if (unlikely(ret)) {
835 unlock_page(page);
836 page_cache_release(page);
837 goto failed;
838 }
839
840 gfs2_trans_add_bh(ip->i_gl, dibh, 1);
841
842 if (gfs2_is_stuffed(ip))
843 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
844
Steven Whitehousebf36a712007-10-17 08:35:19 +0100845 if (!gfs2_is_writeback(ip))
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700846 gfs2_page_add_databufs(ip, page, from, to);
847
848 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
849
Steven Whitehouse9656b2c2008-01-08 08:14:30 +0000850 if (likely(ret >= 0) && (inode->i_size > ip->i_di.di_size)) {
851 di = (struct gfs2_dinode *)dibh->b_data;
852 ip->i_di.di_size = inode->i_size;
853 di->di_size = cpu_to_be64(inode->i_size);
854 mark_inode_dirty(inode);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700855 }
856
857 if (inode == sdp->sd_rindex)
858 adjust_fs_space(inode);
859
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000860 brelse(dibh);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000861 gfs2_trans_end(sdp);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700862failed:
Steven Whitehouse6dbd8222008-01-10 15:18:55 +0000863 if (al) {
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000864 gfs2_inplace_release(ip);
865 gfs2_quota_unlock(ip);
866 gfs2_alloc_put(ip);
867 }
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700868 gfs2_glock_dq(&ip->i_gh);
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000869 gfs2_holder_uninit(&ip->i_gh);
Steven Whitehouse7765ec22007-10-16 01:25:07 -0700870 return ret;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000871}
872
873/**
Robert Peterson8fb68592007-06-12 11:24:36 -0500874 * gfs2_set_page_dirty - Page dirtying function
875 * @page: The page to dirty
876 *
877 * Returns: 1 if it dirtyed the page, or 0 otherwise
878 */
879
880static int gfs2_set_page_dirty(struct page *page)
881{
Steven Whitehouse55610932007-10-17 08:47:38 +0100882 SetPageChecked(page);
Robert Peterson8fb68592007-06-12 11:24:36 -0500883 return __set_page_dirty_buffers(page);
884}
885
886/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000887 * gfs2_bmap - Block map function
888 * @mapping: Address space info
889 * @lblock: The block to map
890 *
891 * Returns: The disk address for the block or 0 on hole or error
892 */
893
894static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
895{
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400896 struct gfs2_inode *ip = GFS2_I(mapping->host);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000897 struct gfs2_holder i_gh;
898 sector_t dblock = 0;
899 int error;
900
David Teiglandb3b94fa2006-01-16 16:50:04 +0000901 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
902 if (error)
903 return 0;
904
905 if (!gfs2_is_stuffed(ip))
Bob Petersone9e1ef22007-12-10 14:13:27 -0600906 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000907
908 gfs2_glock_dq_uninit(&i_gh);
909
910 return dblock;
911}
912
Steven Whitehoused7b616e2007-09-02 10:48:13 +0100913static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
914{
915 struct gfs2_bufdata *bd;
916
917 lock_buffer(bh);
918 gfs2_log_lock(sdp);
919 clear_buffer_dirty(bh);
920 bd = bh->b_private;
921 if (bd) {
Steven Whitehouse16615be2007-09-17 10:59:52 +0100922 if (!list_empty(&bd->bd_le.le_list) && !buffer_pinned(bh))
923 list_del_init(&bd->bd_le.le_list);
924 else
925 gfs2_remove_from_journal(bh, current->journal_info, 0);
Steven Whitehoused7b616e2007-09-02 10:48:13 +0100926 }
927 bh->b_bdev = NULL;
928 clear_buffer_mapped(bh);
929 clear_buffer_req(bh);
930 clear_buffer_new(bh);
931 gfs2_log_unlock(sdp);
932 unlock_buffer(bh);
933}
934
Steven Whitehouse8628de02006-03-31 16:48:41 -0500935static void gfs2_invalidatepage(struct page *page, unsigned long offset)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000936{
Steven Whitehoused7b616e2007-09-02 10:48:13 +0100937 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
938 struct buffer_head *bh, *head;
939 unsigned long pos = 0;
940
David Teiglandb3b94fa2006-01-16 16:50:04 +0000941 BUG_ON(!PageLocked(page));
Robert Peterson8fb68592007-06-12 11:24:36 -0500942 if (offset == 0)
943 ClearPageChecked(page);
Steven Whitehoused7b616e2007-09-02 10:48:13 +0100944 if (!page_has_buffers(page))
945 goto out;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000946
Steven Whitehoused7b616e2007-09-02 10:48:13 +0100947 bh = head = page_buffers(page);
948 do {
949 if (offset <= pos)
950 gfs2_discard(sdp, bh);
951 pos += bh->b_size;
952 bh = bh->b_this_page;
953 } while (bh != head);
954out:
955 if (offset == 0)
956 try_to_release_page(page, 0);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000957}
958
Steven Whitehousec7b33832006-12-14 18:24:26 +0000959/**
960 * gfs2_ok_for_dio - check that dio is valid on this file
961 * @ip: The inode
962 * @rw: READ or WRITE
963 * @offset: The offset at which we are reading or writing
964 *
965 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
966 * 1 (to accept the i/o request)
967 */
968static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
969{
970 /*
971 * Should we return an error here? I can't see that O_DIRECT for
Steven Whitehouse55610932007-10-17 08:47:38 +0100972 * a stuffed file makes any sense. For now we'll silently fall
973 * back to buffered I/O
Steven Whitehousec7b33832006-12-14 18:24:26 +0000974 */
Steven Whitehousec7b33832006-12-14 18:24:26 +0000975 if (gfs2_is_stuffed(ip))
976 return 0;
977
Bob Petersonacb57a32008-09-11 15:35:37 -0400978 if (offset >= i_size_read(&ip->i_inode))
Steven Whitehousec7b33832006-12-14 18:24:26 +0000979 return 0;
980 return 1;
981}
982
983
984
Steven Whitehousea9e5f4d2006-07-25 17:24:12 -0400985static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
986 const struct iovec *iov, loff_t offset,
987 unsigned long nr_segs)
Steven Whitehoused1665e42006-02-14 11:54:42 +0000988{
989 struct file *file = iocb->ki_filp;
990 struct inode *inode = file->f_mapping->host;
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400991 struct gfs2_inode *ip = GFS2_I(inode);
Steven Whitehoused1665e42006-02-14 11:54:42 +0000992 struct gfs2_holder gh;
993 int rv;
994
995 /*
Steven Whitehousec7b33832006-12-14 18:24:26 +0000996 * Deferred lock, even if its a write, since we do no allocation
997 * on this path. All we need change is atime, and this lock mode
998 * ensures that other nodes have flushed their buffered read caches
999 * (i.e. their page cache entries for this inode). We do not,
1000 * unfortunately have the option of only flushing a range like
1001 * the VFS does.
Steven Whitehoused1665e42006-02-14 11:54:42 +00001002 */
Steven Whitehouse719ee342008-09-18 13:53:59 +01001003 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1004 rv = gfs2_glock_nq(&gh);
Steven Whitehoused1665e42006-02-14 11:54:42 +00001005 if (rv)
Steven Whitehousec7b33832006-12-14 18:24:26 +00001006 return rv;
1007 rv = gfs2_ok_for_dio(ip, rw, offset);
1008 if (rv != 1)
1009 goto out; /* dio not valid, fall back to buffered i/o */
Steven Whitehoused1665e42006-02-14 11:54:42 +00001010
Steven Whitehousec7b33832006-12-14 18:24:26 +00001011 rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev,
1012 iov, offset, nr_segs,
1013 gfs2_get_block_direct, NULL);
Steven Whitehoused1665e42006-02-14 11:54:42 +00001014out:
1015 gfs2_glock_dq_m(1, &gh);
1016 gfs2_holder_uninit(&gh);
Steven Whitehoused1665e42006-02-14 11:54:42 +00001017 return rv;
1018}
1019
1020/**
Steven Whitehouse623d9352006-08-31 12:14:44 -04001021 * gfs2_releasepage - free the metadata associated with a page
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001022 * @page: the page that's being released
1023 * @gfp_mask: passed from Linux VFS, ignored by us
1024 *
1025 * Call try_to_free_buffers() if the buffers in this page can be
1026 * released.
1027 *
1028 * Returns: 0
1029 */
1030
1031int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1032{
1033 struct inode *aspace = page->mapping->host;
1034 struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
1035 struct buffer_head *bh, *head;
1036 struct gfs2_bufdata *bd;
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001037
1038 if (!page_has_buffers(page))
Steven Whitehouse891ba6d2007-09-20 15:26:33 +01001039 return 0;
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001040
Steven Whitehousebb3b0e32007-08-16 16:03:57 +01001041 gfs2_log_lock(sdp);
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001042 head = bh = page_buffers(page);
1043 do {
Steven Whitehousebb3b0e32007-08-16 16:03:57 +01001044 if (atomic_read(&bh->b_count))
1045 goto cannot_release;
1046 bd = bh->b_private;
1047 if (bd && bd->bd_ail)
1048 goto cannot_release;
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001049 gfs2_assert_warn(sdp, !buffer_pinned(bh));
Steven Whitehouse623d9352006-08-31 12:14:44 -04001050 gfs2_assert_warn(sdp, !buffer_dirty(bh));
Steven Whitehousebb3b0e32007-08-16 16:03:57 +01001051 bh = bh->b_this_page;
1052 } while(bh != head);
1053 gfs2_log_unlock(sdp);
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001054
Steven Whitehousebb3b0e32007-08-16 16:03:57 +01001055 head = bh = page_buffers(page);
1056 do {
Steven Whitehouse623d9352006-08-31 12:14:44 -04001057 gfs2_log_lock(sdp);
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001058 bd = bh->b_private;
1059 if (bd) {
1060 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1061 gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
Steven Whitehoused7b616e2007-09-02 10:48:13 +01001062 if (!list_empty(&bd->bd_le.le_list)) {
1063 if (!buffer_pinned(bh))
1064 list_del_init(&bd->bd_le.le_list);
1065 else
1066 bd = NULL;
1067 }
1068 if (bd)
1069 bd->bd_bh = NULL;
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001070 bh->b_private = NULL;
1071 }
Steven Whitehouse623d9352006-08-31 12:14:44 -04001072 gfs2_log_unlock(sdp);
1073 if (bd)
1074 kmem_cache_free(gfs2_bufdata_cachep, bd);
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001075
1076 bh = bh->b_this_page;
Steven Whitehouse166afcc2006-08-24 15:59:40 -04001077 } while (bh != head);
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001078
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001079 return try_to_free_buffers(page);
Steven Whitehousebb3b0e32007-08-16 16:03:57 +01001080cannot_release:
1081 gfs2_log_unlock(sdp);
1082 return 0;
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001083}
1084
Steven Whitehouse55610932007-10-17 08:47:38 +01001085static const struct address_space_operations gfs2_writeback_aops = {
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +01001086 .writepage = gfs2_writeback_writepage,
Steven Whitehouse55610932007-10-17 08:47:38 +01001087 .writepages = gfs2_writeback_writepages,
1088 .readpage = gfs2_readpage,
1089 .readpages = gfs2_readpages,
1090 .sync_page = block_sync_page,
1091 .write_begin = gfs2_write_begin,
1092 .write_end = gfs2_write_end,
1093 .bmap = gfs2_bmap,
1094 .invalidatepage = gfs2_invalidatepage,
1095 .releasepage = gfs2_releasepage,
1096 .direct_IO = gfs2_direct_IO,
Steven Whitehousee5d9dc22008-01-03 11:31:38 +00001097 .migratepage = buffer_migrate_page,
Steven Whitehouse55610932007-10-17 08:47:38 +01001098};
1099
1100static const struct address_space_operations gfs2_ordered_aops = {
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +01001101 .writepage = gfs2_ordered_writepage,
David Teiglandb3b94fa2006-01-16 16:50:04 +00001102 .readpage = gfs2_readpage,
Steven Whitehousefd88de562006-05-05 16:59:11 -04001103 .readpages = gfs2_readpages,
David Teiglandb3b94fa2006-01-16 16:50:04 +00001104 .sync_page = block_sync_page,
Steven Whitehouse7765ec22007-10-16 01:25:07 -07001105 .write_begin = gfs2_write_begin,
1106 .write_end = gfs2_write_end,
Robert Peterson8fb68592007-06-12 11:24:36 -05001107 .set_page_dirty = gfs2_set_page_dirty,
David Teiglandb3b94fa2006-01-16 16:50:04 +00001108 .bmap = gfs2_bmap,
1109 .invalidatepage = gfs2_invalidatepage,
Steven Whitehouse4340fe62006-07-11 09:46:33 -04001110 .releasepage = gfs2_releasepage,
David Teiglandb3b94fa2006-01-16 16:50:04 +00001111 .direct_IO = gfs2_direct_IO,
Steven Whitehousee5d9dc22008-01-03 11:31:38 +00001112 .migratepage = buffer_migrate_page,
David Teiglandb3b94fa2006-01-16 16:50:04 +00001113};
1114
Steven Whitehouse55610932007-10-17 08:47:38 +01001115static const struct address_space_operations gfs2_jdata_aops = {
Steven Whitehouse9ff8ec32007-09-28 13:49:05 +01001116 .writepage = gfs2_jdata_writepage,
Steven Whitehouseb8e7cbb2007-10-17 09:04:24 +01001117 .writepages = gfs2_jdata_writepages,
Steven Whitehouse55610932007-10-17 08:47:38 +01001118 .readpage = gfs2_readpage,
1119 .readpages = gfs2_readpages,
1120 .sync_page = block_sync_page,
1121 .write_begin = gfs2_write_begin,
1122 .write_end = gfs2_write_end,
1123 .set_page_dirty = gfs2_set_page_dirty,
1124 .bmap = gfs2_bmap,
1125 .invalidatepage = gfs2_invalidatepage,
1126 .releasepage = gfs2_releasepage,
1127};
1128
1129void gfs2_set_aops(struct inode *inode)
1130{
1131 struct gfs2_inode *ip = GFS2_I(inode);
1132
1133 if (gfs2_is_writeback(ip))
1134 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1135 else if (gfs2_is_ordered(ip))
1136 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1137 else if (gfs2_is_jdata(ip))
1138 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1139 else
1140 BUG();
1141}
1142