blob: 950b8be68e415435d530196810ac733392c5035f [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;
Mike Christie2a222ca2016-06-05 14:31:43 -050040 int write_flags = REQ_META | REQ_PRIO |
41 (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : 0);
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)) {
Mike Christie2a222ca2016-06-05 14:31:43 -050082 submit_bh(REQ_OP_WRITE, write_flags, bh);
Steven Whitehouse4a0f9a32009-04-20 08:16:26 +010083 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
Steven Whitehouse1b2ad412014-03-31 17:48:27 +0100100const struct address_space_operations gfs2_rgrp_aops = {
101 .writepage = gfs2_aspace_writepage,
102 .releasepage = gfs2_releasepage,
103};
104
David Teiglandb3b94fa2006-01-16 16:50:04 +0000105/**
Steven Whitehouse6802e342008-05-21 17:03:22 +0100106 * gfs2_getbuf - Get a buffer with a given address space
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500107 * @gl: the glock
David Teiglandb3b94fa2006-01-16 16:50:04 +0000108 * @blkno: the block number (filesystem scope)
109 * @create: 1 if the buffer should be created
110 *
111 * Returns: the buffer
112 */
113
Steven Whitehouse6802e342008-05-21 17:03:22 +0100114struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000115{
Steven Whitehouse009d8512009-12-08 12:12:13 +0000116 struct address_space *mapping = gfs2_glock2aspace(gl);
Bob Peterson15562c42015-03-16 11:52:05 -0500117 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000118 struct page *page;
119 struct buffer_head *bh;
120 unsigned int shift;
121 unsigned long index;
122 unsigned int bufnum;
123
Steven Whitehouse70d4ee92013-12-06 16:19:54 +0000124 if (mapping == NULL)
125 mapping = &sdp->sd_aspace;
126
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300127 shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000128 index = blkno >> shift; /* convert block to page */
129 bufnum = blkno - (index << shift); /* block buf index within page */
130
131 if (create) {
132 for (;;) {
Steven Whitehousecb4c0312006-11-23 11:16:32 -0500133 page = grab_cache_page(mapping, index);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000134 if (page)
135 break;
136 yield();
137 }
138 } else {
Mel Gorman2457aec2014-06-04 16:10:31 -0700139 page = find_get_page_flags(mapping, index,
140 FGP_LOCK|FGP_ACCESSED);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000141 if (!page)
142 return NULL;
143 }
144
145 if (!page_has_buffers(page))
146 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
147
148 /* Locate header for our buffer within our page */
149 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
150 /* Do nothing */;
151 get_bh(bh);
152
153 if (!buffer_mapped(bh))
154 map_bh(bh, sdp->sd_vfs, blkno);
155
156 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300157 put_page(page);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000158
159 return bh;
160}
161
162static void meta_prep_new(struct buffer_head *bh)
163{
164 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
165
166 lock_buffer(bh);
167 clear_buffer_dirty(bh);
168 set_buffer_uptodate(bh);
169 unlock_buffer(bh);
170
171 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
172}
173
174/**
175 * gfs2_meta_new - Get a block
176 * @gl: The glock associated with this block
177 * @blkno: The block number
178 *
179 * Returns: The buffer
180 */
181
Steven Whitehousecd915492006-09-04 12:49:07 -0400182struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000183{
184 struct buffer_head *bh;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100185 bh = gfs2_getbuf(gl, blkno, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000186 meta_prep_new(bh);
187 return bh;
188}
189
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600190static void gfs2_meta_read_endio(struct bio *bio)
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600191{
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600192 struct bio_vec *bvec;
193 int i;
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600194
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600195 bio_for_each_segment_all(bvec, bio, i) {
196 struct page *page = bvec->bv_page;
197 struct buffer_head *bh = page_buffers(page);
198 unsigned int len = bvec->bv_len;
199
200 while (bh_offset(bh) < bvec->bv_offset)
201 bh = bh->b_this_page;
202 do {
203 struct buffer_head *next = bh->b_this_page;
204 len -= bh->b_size;
205 bh->b_end_io(bh, !bio->bi_error);
206 bh = next;
207 } while (bh && len);
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600208 }
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600209 bio_put(bio);
210}
211
212/*
213 * Submit several consecutive buffer head I/O requests as a single bio I/O
214 * request. (See submit_bh_wbc.)
215 */
Mike Christiee1b1afa2016-06-05 14:31:56 -0500216static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[],
217 int num)
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600218{
219 struct buffer_head *bh = bhs[0];
220 struct bio *bio;
221 int i;
222
223 if (!num)
224 return;
225
226 bio = bio_alloc(GFP_NOIO, num);
227 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
228 bio->bi_bdev = bh->b_bdev;
229 for (i = 0; i < num; i++) {
230 bh = bhs[i];
231 bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
232 }
233 bio->bi_end_io = gfs2_meta_read_endio;
Mike Christiee1b1afa2016-06-05 14:31:56 -0500234 bio_set_op_attrs(bio, op, op_flags);
Mike Christie4e49ea42016-06-05 14:31:41 -0500235 submit_bio(bio);
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600236}
237
David Teiglandb3b94fa2006-01-16 16:50:04 +0000238/**
239 * gfs2_meta_read - Read a block from disk
240 * @gl: The glock covering the block
241 * @blkno: The block number
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400242 * @flags: flags
David Teiglandb3b94fa2006-01-16 16:50:04 +0000243 * @bhp: the place where the buffer is returned (NULL on failure)
244 *
245 * Returns: errno
246 */
247
Steven Whitehousecd915492006-09-04 12:49:07 -0400248int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600249 int rahead, struct buffer_head **bhp)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000250{
Bob Peterson15562c42015-03-16 11:52:05 -0500251 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600252 struct buffer_head *bh, *bhs[2];
253 int num = 0;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100254
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900255 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
256 *bhp = NULL;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100257 return -EIO;
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900258 }
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100259
260 *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
261
262 lock_buffer(bh);
263 if (buffer_uptodate(bh)) {
264 unlock_buffer(bh);
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600265 flags &= ~DIO_WAIT;
266 } else {
267 bh->b_end_io = end_buffer_read_sync;
268 get_bh(bh);
269 bhs[num++] = bh;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100270 }
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600271
272 if (rahead) {
273 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
274
275 lock_buffer(bh);
276 if (buffer_uptodate(bh)) {
277 unlock_buffer(bh);
278 brelse(bh);
279 } else {
280 bh->b_end_io = end_buffer_read_sync;
281 bhs[num++] = bh;
282 }
283 }
284
Mike Christiee1b1afa2016-06-05 14:31:56 -0500285 gfs2_submit_bhs(REQ_OP_READ, READ_SYNC | REQ_META | REQ_PRIO, bhs, num);
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100286 if (!(flags & DIO_WAIT))
287 return 0;
288
Andreas Gruenbacher39b05552015-11-13 07:44:57 -0600289 bh = *bhp;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100290 wait_on_buffer(bh);
291 if (unlikely(!buffer_uptodate(bh))) {
292 struct gfs2_trans *tr = current->journal_info;
293 if (tr && tr->tr_touched)
294 gfs2_io_error_bh(sdp, bh);
295 brelse(bh);
Masatake YAMATO44b8db12012-06-18 16:31:31 +0900296 *bhp = NULL;
Steven Whitehousec969f58c2009-04-07 14:13:01 +0100297 return -EIO;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400298 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000299
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400300 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000301}
302
303/**
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400304 * gfs2_meta_wait - Reread a block from disk
David Teiglandb3b94fa2006-01-16 16:50:04 +0000305 * @sdp: the filesystem
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400306 * @bh: The block to wait for
David Teiglandb3b94fa2006-01-16 16:50:04 +0000307 *
308 * Returns: errno
309 */
310
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400311int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000312{
313 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
314 return -EIO;
315
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400316 wait_on_buffer(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000317
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400318 if (!buffer_uptodate(bh)) {
319 struct gfs2_trans *tr = current->journal_info;
320 if (tr && tr->tr_touched)
321 gfs2_io_error_bh(sdp, bh);
322 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000323 }
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400324 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
325 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000326
327 return 0;
328}
329
Bob Peterson68cd4ce2016-05-02 11:53:35 -0500330void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
Steven Whitehouse16615be2007-09-17 10:59:52 +0100331{
Steven Whitehouse009d8512009-12-08 12:12:13 +0000332 struct address_space *mapping = bh->b_page->mapping;
333 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100334 struct gfs2_bufdata *bd = bh->b_private;
Bob Peterson68cd4ce2016-05-02 11:53:35 -0500335 struct gfs2_trans *tr = current->journal_info;
Bob Peterson502be2a2013-12-13 08:31:06 -0500336 int was_pinned = 0;
Steven Whitehouse009d8512009-12-08 12:12:13 +0000337
Steven Whitehouse16615be2007-09-17 10:59:52 +0100338 if (test_clear_buffer_pinned(bh)) {
Steven Whitehouse627c10b2011-04-14 14:09:52 +0100339 trace_gfs2_pin(bd, 0);
Benjamin Marzinski5e687ea2010-05-04 14:29:16 -0500340 atomic_dec(&sdp->sd_log_pinned);
Bob Petersonc0752aa2012-05-01 12:00:34 -0400341 list_del_init(&bd->bd_list);
Bob Peterson68cd4ce2016-05-02 11:53:35 -0500342 if (meta == REMOVE_META)
Steven Whitehouse16615be2007-09-17 10:59:52 +0100343 tr->tr_num_buf_rm++;
Steven Whitehouse022ef4f2014-02-21 21:55:33 +0000344 else
Steven Whitehouse16615be2007-09-17 10:59:52 +0100345 tr->tr_num_databuf_rm++;
Steven Whitehouse16615be2007-09-17 10:59:52 +0100346 tr->tr_touched = 1;
Bob Peterson502be2a2013-12-13 08:31:06 -0500347 was_pinned = 1;
Steven Whitehouse16615be2007-09-17 10:59:52 +0100348 brelse(bh);
349 }
350 if (bd) {
Steven Whitehousec618e872011-03-14 12:40:29 +0000351 spin_lock(&sdp->sd_ail_lock);
Benjamin Marzinski16ca9412013-04-05 20:31:46 -0500352 if (bd->bd_tr) {
Steven Whitehouse16615be2007-09-17 10:59:52 +0100353 gfs2_trans_add_revoke(sdp, bd);
Bob Peterson502be2a2013-12-13 08:31:06 -0500354 } else if (was_pinned) {
355 bh->b_private = NULL;
356 kmem_cache_free(gfs2_bufdata_cachep, bd);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100357 }
Steven Whitehousec618e872011-03-14 12:40:29 +0000358 spin_unlock(&sdp->sd_ail_lock);
Steven Whitehouse16615be2007-09-17 10:59:52 +0100359 }
360 clear_buffer_dirty(bh);
361 clear_buffer_uptodate(bh);
362}
363
David Teiglandb3b94fa2006-01-16 16:50:04 +0000364/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000365 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
366 * @ip: the inode who owns the buffers
367 * @bstart: the first buffer in the run
368 * @blen: the number of buffers in the run
369 *
370 */
371
Steven Whitehousecd915492006-09-04 12:49:07 -0400372void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000373{
Steven Whitehousefeaa7bb2006-06-14 15:32:57 -0400374 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000375 struct buffer_head *bh;
376
377 while (blen) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100378 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000379 if (bh) {
Steven Whitehouse1ad38c42007-09-03 11:01:33 +0100380 lock_buffer(bh);
381 gfs2_log_lock(sdp);
Bob Peterson68cd4ce2016-05-02 11:53:35 -0500382 gfs2_remove_from_journal(bh, REMOVE_META);
Steven Whitehouse1ad38c42007-09-03 11:01:33 +0100383 gfs2_log_unlock(sdp);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000384 unlock_buffer(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000385 brelse(bh);
386 }
387
388 bstart++;
389 blen--;
390 }
391}
392
393/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000394 * gfs2_meta_indirect_buffer - Get a metadata buffer
395 * @ip: The GFS2 inode
396 * @height: The level of this buf in the metadata (indir addr) tree (if any)
397 * @num: The block number (device relative) of the buffer
David Teiglandb3b94fa2006-01-16 16:50:04 +0000398 * @bhp: the buffer is returned here
399 *
David Teiglandb3b94fa2006-01-16 16:50:04 +0000400 * Returns: errno
401 */
402
Steven Whitehousecd915492006-09-04 12:49:07 -0400403int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
Bob Petersonf2f9c812012-05-10 08:33:55 -0400404 struct buffer_head **bhp)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000405{
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400406 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
407 struct gfs2_glock *gl = ip->i_gl;
Steven Whitehousef91a0d32007-10-15 16:29:05 +0100408 struct buffer_head *bh;
409 int ret = 0;
Bob Petersonf2f9c812012-05-10 08:33:55 -0400410 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600411 int rahead = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000412
Andreas Gruenbacherc8d57702015-11-11 15:00:35 -0600413 if (num == ip->i_no_addr)
414 rahead = ip->i_rahead;
415
416 ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
Bob Petersonf2f9c812012-05-10 08:33:55 -0400417 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
418 brelse(bh);
419 ret = -EIO;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400420 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000421 *bhp = bh;
Steven Whitehousef91a0d32007-10-15 16:29:05 +0100422 return ret;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000423}
424
425/**
426 * gfs2_meta_ra - start readahead on an extent of a file
427 * @gl: the glock the blocks belong to
428 * @dblock: the starting disk block
429 * @extlen: the number of blocks in the extent
430 *
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400431 * returns: the first buffer in the extent
David Teiglandb3b94fa2006-01-16 16:50:04 +0000432 */
433
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400434struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000435{
Bob Peterson15562c42015-03-16 11:52:05 -0500436 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000437 struct buffer_head *first_bh, *bh;
Steven Whitehousecd915492006-09-04 12:49:07 -0400438 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
Steven Whitehouse568f4c92006-02-27 12:00:42 -0500439 sdp->sd_sb.sb_bsize_shift;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000440
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400441 BUG_ON(!extlen);
442
443 if (max_ra < 1)
444 max_ra = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000445 if (extlen > max_ra)
446 extlen = max_ra;
447
Steven Whitehouse6802e342008-05-21 17:03:22 +0100448 first_bh = gfs2_getbuf(gl, dblock, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000449
450 if (buffer_uptodate(first_bh))
451 goto out;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400452 if (!buffer_locked(first_bh))
Mike Christiedfec8a12016-06-05 14:31:44 -0500453 ll_rw_block(REQ_OP_READ, READ_SYNC | REQ_META, 1, &first_bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000454
455 dblock++;
456 extlen--;
457
458 while (extlen) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100459 bh = gfs2_getbuf(gl, dblock, CREATE);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000460
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400461 if (!buffer_uptodate(bh) && !buffer_locked(bh))
Christoph Hellwig70246282016-07-19 11:28:41 +0200462 ll_rw_block(REQ_OP_READ, REQ_RAHEAD | REQ_META, 1, &bh);
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400463 brelse(bh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000464 dblock++;
465 extlen--;
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400466 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
467 goto out;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000468 }
469
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400470 wait_on_buffer(first_bh);
Steven Whitehousea91ea692006-09-04 12:04:26 -0400471out:
Steven Whitehouse7276b3b2006-09-21 17:05:23 -0400472 return first_bh;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000473}
474