blob: 22255d96b27efbb9c3a93e6db8678a147d99548b [file] [log] [blame]
David Teiglandb3b94fa2006-01-16 16:50:04 +00001/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
Bob Peterson091806ed2008-04-29 12:35:48 -05003 * 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/mm.h>
16#include <linux/pagemap.h>
17#include <linux/writeback.h>
18#include <linux/swap.h>
19#include <linux/delay.h>
Steven Whitehouse2e565bb2006-10-02 11:38:25 -040020#include <linux/bio.h>
Steven Whitehouse5c676f62006-02-27 17:23:27 -050021#include <linux/gfs2_ondisk.h>
David Teiglandb3b94fa2006-01-16 16:50:04 +000022
23#include "gfs2.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050024#include "incore.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000025#include "glock.h"
26#include "glops.h"
27#include "inode.h"
28#include "log.h"
29#include "lops.h"
30#include "meta_io.h"
31#include "rgrp.h"
32#include "trans.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050033#include "util.h"
Steven Whitehouse627c10b2011-04-14 14:09:52 +010034#include "trace_gfs2.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000035
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010036static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
David Teiglandb3b94fa2006-01-16 16:50:04 +000037{
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010038 struct buffer_head *bh, *head;
39 int nr_underway = 0;
Christoph Hellwig65299a32011-08-23 14:50:29 +020040 int write_op = REQ_META | REQ_PRIO |
Jens Axboe721a9602011-03-09 11:56:30 +010041 (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
David Teiglandb3b94fa2006-01-16 16:50:04 +000042
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010043 BUG_ON(!PageLocked(page));
44 BUG_ON(!page_has_buffers(page));
45
46 head = page_buffers(page);
47 bh = head;
48
49 do {
50 if (!buffer_mapped(bh))
51 continue;
52 /*
53 * If it's a fully non-blocking write attempt and we cannot
54 * lock the buffer then redirty the page. Note that this can
Artem Bityutskiye76e0ec2012-07-25 18:12:13 +030055 * potentially cause a busy-wait loop from flusher thread and kswapd
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010056 * activity, but those code paths have their own higher-level
57 * throttling.
58 */
Wu Fengguang1b430be2010-10-26 14:21:26 -070059 if (wbc->sync_mode != WB_SYNC_NONE) {
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010060 lock_buffer(bh);
61 } else if (!trylock_buffer(bh)) {
62 redirty_page_for_writepage(wbc, page);
63 continue;
64 }
65 if (test_clear_buffer_dirty(bh)) {
66 mark_buffer_async_write(bh);
67 } else {
68 unlock_buffer(bh);
69 }
70 } while ((bh = bh->b_this_page) != head);
71
72 /*
73 * The page and its buffers are protected by PageWriteback(), so we can
74 * drop the bh refcounts early.
75 */
76 BUG_ON(PageWriteback(page));
77 set_page_writeback(page);
78
79 do {
80 struct buffer_head *next = bh->b_this_page;
81 if (buffer_async_write(bh)) {
82 submit_bh(write_op, bh);
83 nr_underway++;
84 }
85 bh = next;
86 } while (bh != head);
87 unlock_page(page);
88
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010089 if (nr_underway == 0)
90 end_page_writeback(page);
91
Bob Petersoneaefbf92010-05-11 17:35:34 -040092 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +000093}
94
Steven Whitehouse009d8512009-12-08 12:12:13 +000095const struct address_space_operations gfs2_meta_aops = {
David Teiglandb3b94fa2006-01-16 16:50:04 +000096 .writepage = gfs2_aspace_writepage,
Steven Whitehouse4340fe62006-07-11 09:46:33 -040097 .releasepage = gfs2_releasepage,
David Teiglandb3b94fa2006-01-16 16:50:04 +000098};
99
100/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000101 * gfs2_meta_sync - Sync all buffers associated with a glock
102 * @gl: The glock
David Teiglandb3b94fa2006-01-16 16:50:04 +0000103 *
104 */
105
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400106void gfs2_meta_sync(struct gfs2_glock *gl)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000107{
Steven Whitehouse009d8512009-12-08 12:12:13 +0000108 struct address_space *mapping = gfs2_glock2aspace(gl);
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400109 int error;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000110
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400111 filemap_fdatawrite(mapping);
112 error = filemap_fdatawait(mapping);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000113
114 if (error)
115 gfs2_io_error(gl->gl_sbd);
116}
117
118/**
Steven Whitehouse6802e342008-05-21 17:03:22 +0100119 * gfs2_getbuf - Get a buffer with a given address space
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500120 * @gl: the glock
David Teiglandb3b94fa2006-01-16 16:50:04 +0000121 * @blkno: the block number (filesystem scope)
122 * @create: 1 if the buffer should be created
123 *
124 * Returns: the buffer
125 */
126
Steven Whitehouse6802e342008-05-21 17:03:22 +0100127struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000128{
Steven Whitehouse009d8512009-12-08 12:12:13 +0000129 struct address_space *mapping = gfs2_glock2aspace(gl);
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500130 struct gfs2_sbd *sdp = gl->gl_sbd;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000131 struct page *page;
132 struct buffer_head *bh;
133 unsigned int shift;
134 unsigned long index;
135 unsigned int bufnum;
136
137 shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
138 index = blkno >> shift; /* convert block to page */
139 bufnum = blkno - (index << shift); /* block buf index within page */
140
141 if (create) {
142 for (;;) {
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500143 page = grab_cache_page(mapping, index);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000144 if (page)
145 break;
146 yield();
147 }
148 } else {
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500149 page = find_lock_page(mapping, index);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000150 if (!page)
151 return NULL;
152 }
153
154 if (!page_has_buffers(page))
155 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
156
157 /* Locate header for our buffer within our page */
158 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
159 /* Do nothing */;
160 get_bh(bh);
161
162 if (!buffer_mapped(bh))
163 map_bh(bh, sdp->sd_vfs, blkno);
164
165 unlock_page(page);
166 mark_page_accessed(page);
167 page_cache_release(page);
168
169 return bh;
170}
171
172static void meta_prep_new(struct buffer_head *bh)
173{
174 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
175
176 lock_buffer(bh);
177 clear_buffer_dirty(bh);
178 set_buffer_uptodate(bh);
179 unlock_buffer(bh);
180
181 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
182}
183
184/**
185 * gfs2_meta_new - Get a block
186 * @gl: The glock associated with this block
187 * @blkno: The block number
188 *
189 * Returns: The buffer
190 */
191
Steven Whitehousecd915492006-09-04 12:49:07 -0400192struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000193{
194 struct buffer_head *bh;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100195 bh = gfs2_getbuf(gl, blkno, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000196 meta_prep_new(bh);
197 return bh;
198}
199
200/**
201 * gfs2_meta_read - Read a block from disk
202 * @gl: The glock covering the block
203 * @blkno: The block number
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400204 * @flags: flags
David Teiglandb3b94fa2006-01-16 16:50:04 +0000205 * @bhp: the place where the buffer is returned (NULL on failure)
206 *
207 * Returns: errno
208 */
209
Steven Whitehousecd915492006-09-04 12:49:07 -0400210int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
David Teiglandb3b94fa2006-01-16 16:50:04 +0000211 struct buffer_head **bhp)
212{
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100213 struct gfs2_sbd *sdp = gl->gl_sbd;
214 struct buffer_head *bh;
215
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900216 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
217 *bhp = NULL;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100218 return -EIO;
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900219 }
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100220
221 *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
222
223 lock_buffer(bh);
224 if (buffer_uptodate(bh)) {
225 unlock_buffer(bh);
226 return 0;
227 }
228 bh->b_end_io = end_buffer_read_sync;
229 get_bh(bh);
Christoph Hellwig65299a32011-08-23 14:50:29 +0200230 submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh);
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100231 if (!(flags & DIO_WAIT))
232 return 0;
233
234 wait_on_buffer(bh);
235 if (unlikely(!buffer_uptodate(bh))) {
236 struct gfs2_trans *tr = current->journal_info;
237 if (tr && tr->tr_touched)
238 gfs2_io_error_bh(sdp, bh);
239 brelse(bh);
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900240 *bhp = NULL;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100241 return -EIO;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400242 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000243
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400244 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000245}
246
247/**
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400248 * gfs2_meta_wait - Reread a block from disk
David Teiglandb3b94fa2006-01-16 16:50:04 +0000249 * @sdp: the filesystem
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400250 * @bh: The block to wait for
David Teiglandb3b94fa2006-01-16 16:50:04 +0000251 *
252 * Returns: errno
253 */
254
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400255int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000256{
257 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
258 return -EIO;
259
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400260 wait_on_buffer(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000261
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400262 if (!buffer_uptodate(bh)) {
263 struct gfs2_trans *tr = current->journal_info;
264 if (tr && tr->tr_touched)
265 gfs2_io_error_bh(sdp, bh);
266 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000267 }
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400268 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
269 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000270
271 return 0;
272}
273
274/**
Steven Whitehouse586dfda2006-01-18 11:32:00 +0000275 * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
David Teiglandb3b94fa2006-01-16 16:50:04 +0000276 * @gl: the glock the buffer belongs to
277 * @bh: The buffer to be attached to
Steven Whitehouse586dfda2006-01-18 11:32:00 +0000278 * @meta: Flag to indicate whether its metadata or not
David Teiglandb3b94fa2006-01-16 16:50:04 +0000279 */
280
Steven Whitehouse568f4c92006-02-27 12:00:42 -0500281void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
282 int meta)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000283{
284 struct gfs2_bufdata *bd;
285
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000286 if (meta)
287 lock_page(bh->b_page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000288
Steven Whitehouse5c676f62006-02-27 17:23:27 -0500289 if (bh->b_private) {
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000290 if (meta)
291 unlock_page(bh->b_page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000292 return;
293 }
294
Bob Peterson3e5cd082008-01-16 08:45:39 -0600295 bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000296 bd->bd_bh = bh;
297 bd->bd_gl = gl;
298
Steven Whitehouse82ffa512006-09-04 14:47:06 -0400299 if (meta)
Bob Petersonc0752aa2012-05-01 12:00:34 -0400300 lops_init_le(bd, &gfs2_buf_lops);
Steven Whitehouse82ffa512006-09-04 14:47:06 -0400301 else
Bob Petersonc0752aa2012-05-01 12:00:34 -0400302 lops_init_le(bd, &gfs2_databuf_lops);
Steven Whitehouse5c676f62006-02-27 17:23:27 -0500303 bh->b_private = bd;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000304
Steven Whitehouse18ec7d52006-02-08 11:50:51 +0000305 if (meta)
306 unlock_page(bh->b_page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000307}
308
Steven Whitehouse16615be2007-09-17 10:59:52 +0100309void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
310{
Steven Whitehouse009d8512009-12-08 12:12:13 +0000311 struct address_space *mapping = bh->b_page->mapping;
312 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100313 struct gfs2_bufdata *bd = bh->b_private;
Steven Whitehouse009d8512009-12-08 12:12:13 +0000314
Steven Whitehouse16615be2007-09-17 10:59:52 +0100315 if (test_clear_buffer_pinned(bh)) {
Steven Whitehouse627c10b2011-04-14 14:09:52 +0100316 trace_gfs2_pin(bd, 0);
Benjamin Marzinski5e687ea2010-05-04 14:29:16 -0500317 atomic_dec(&sdp->sd_log_pinned);
Bob Petersonc0752aa2012-05-01 12:00:34 -0400318 list_del_init(&bd->bd_list);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100319 if (meta) {
320 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
321 sdp->sd_log_num_buf--;
322 tr->tr_num_buf_rm++;
323 } else {
324 gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
325 sdp->sd_log_num_databuf--;
326 tr->tr_num_databuf_rm++;
327 }
328 tr->tr_touched = 1;
329 brelse(bh);
330 }
331 if (bd) {
Steven Whitehousec618e872011-03-14 12:40:29 +0000332 spin_lock(&sdp->sd_ail_lock);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100333 if (bd->bd_ail) {
Steven Whitehousef91a0d32007-10-15 16:29:05 +0100334 gfs2_remove_from_ail(bd);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100335 bh->b_private = NULL;
336 bd->bd_bh = NULL;
337 bd->bd_blkno = bh->b_blocknr;
338 gfs2_trans_add_revoke(sdp, bd);
339 }
Steven Whitehousec618e872011-03-14 12:40:29 +0000340 spin_unlock(&sdp->sd_ail_lock);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100341 }
342 clear_buffer_dirty(bh);
343 clear_buffer_uptodate(bh);
344}
345
David Teiglandb3b94fa2006-01-16 16:50:04 +0000346/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000347 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
348 * @ip: the inode who owns the buffers
349 * @bstart: the first buffer in the run
350 * @blen: the number of buffers in the run
351 *
352 */
353
Steven Whitehousecd915492006-09-04 12:49:07 -0400354void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000355{
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400356 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000357 struct buffer_head *bh;
358
359 while (blen) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100360 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000361 if (bh) {
Steven Whitehouse1ad38c42007-09-03 11:01:33 +0100362 lock_buffer(bh);
363 gfs2_log_lock(sdp);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100364 gfs2_remove_from_journal(bh, current->journal_info, 1);
Steven Whitehouse1ad38c42007-09-03 11:01:33 +0100365 gfs2_log_unlock(sdp);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000366 unlock_buffer(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000367 brelse(bh);
368 }
369
370 bstart++;
371 blen--;
372 }
373}
374
375/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000376 * gfs2_meta_indirect_buffer - Get a metadata buffer
377 * @ip: The GFS2 inode
378 * @height: The level of this buf in the metadata (indir addr) tree (if any)
379 * @num: The block number (device relative) of the buffer
David Teiglandb3b94fa2006-01-16 16:50:04 +0000380 * @bhp: the buffer is returned here
381 *
David Teiglandb3b94fa2006-01-16 16:50:04 +0000382 * Returns: errno
383 */
384
Steven Whitehousecd915492006-09-04 12:49:07 -0400385int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
Bob Petersonf2f9c812012-05-10 08:33:55 -0400386 struct buffer_head **bhp)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000387{
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400388 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
389 struct gfs2_glock *gl = ip->i_gl;
Steven Whitehousef91a0d32007-10-15 16:29:05 +0100390 struct buffer_head *bh;
391 int ret = 0;
Bob Petersonf2f9c812012-05-10 08:33:55 -0400392 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000393
Bob Petersonf2f9c812012-05-10 08:33:55 -0400394 ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
395 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
396 brelse(bh);
397 ret = -EIO;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400398 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000399 *bhp = bh;
Steven Whitehousef91a0d32007-10-15 16:29:05 +0100400 return ret;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000401}
402
403/**
404 * gfs2_meta_ra - start readahead on an extent of a file
405 * @gl: the glock the blocks belong to
406 * @dblock: the starting disk block
407 * @extlen: the number of blocks in the extent
408 *
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400409 * returns: the first buffer in the extent
David Teiglandb3b94fa2006-01-16 16:50:04 +0000410 */
411
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400412struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000413{
414 struct gfs2_sbd *sdp = gl->gl_sbd;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000415 struct buffer_head *first_bh, *bh;
Steven Whitehousecd915492006-09-04 12:49:07 -0400416 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
Steven Whitehouse568f4c92006-02-27 12:00:42 -0500417 sdp->sd_sb.sb_bsize_shift;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000418
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400419 BUG_ON(!extlen);
420
421 if (max_ra < 1)
422 max_ra = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000423 if (extlen > max_ra)
424 extlen = max_ra;
425
Steven Whitehouse6802e342008-05-21 17:03:22 +0100426 first_bh = gfs2_getbuf(gl, dblock, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000427
428 if (buffer_uptodate(first_bh))
429 goto out;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400430 if (!buffer_locked(first_bh))
Steven Whitehouse20ed0532011-10-31 09:52:02 +0000431 ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000432
433 dblock++;
434 extlen--;
435
436 while (extlen) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100437 bh = gfs2_getbuf(gl, dblock, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000438
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400439 if (!buffer_uptodate(bh) && !buffer_locked(bh))
Steven Whitehouse20ed0532011-10-31 09:52:02 +0000440 ll_rw_block(READA | REQ_META, 1, &bh);
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400441 brelse(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000442 dblock++;
443 extlen--;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400444 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
445 goto out;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000446 }
447
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400448 wait_on_buffer(first_bh);
Steven Whitehousea91ea692006-09-04 12:04:26 -0400449out:
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400450 return first_bh;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000451}
452