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v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
  4 * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
 
 
 
 
  5 */
  6
  7#include <linux/sched.h>
  8#include <linux/slab.h>
  9#include <linux/spinlock.h>
 10#include <linux/completion.h>
 11#include <linux/buffer_head.h>
 12#include <linux/mm.h>
 13#include <linux/pagemap.h>
 14#include <linux/writeback.h>
 15#include <linux/swap.h>
 16#include <linux/delay.h>
 17#include <linux/bio.h>
 18#include <linux/gfs2_ondisk.h>
 19
 20#include "gfs2.h"
 21#include "incore.h"
 22#include "glock.h"
 23#include "glops.h"
 24#include "inode.h"
 25#include "log.h"
 26#include "lops.h"
 27#include "meta_io.h"
 28#include "rgrp.h"
 29#include "trans.h"
 30#include "util.h"
 31#include "trace_gfs2.h"
 32
 33static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
 34{
 35	struct buffer_head *bh, *head;
 36	int nr_underway = 0;
 37	blk_opf_t write_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc);
 
 38
 39	BUG_ON(!PageLocked(page));
 40	BUG_ON(!page_has_buffers(page));
 41
 42	head = page_buffers(page);
 43	bh = head;
 44
 45	do {
 46		if (!buffer_mapped(bh))
 47			continue;
 48		/*
 49		 * If it's a fully non-blocking write attempt and we cannot
 50		 * lock the buffer then redirty the page.  Note that this can
 51		 * potentially cause a busy-wait loop from flusher thread and kswapd
 52		 * activity, but those code paths have their own higher-level
 53		 * throttling.
 54		 */
 55		if (wbc->sync_mode != WB_SYNC_NONE) {
 56			lock_buffer(bh);
 57		} else if (!trylock_buffer(bh)) {
 58			redirty_page_for_writepage(wbc, page);
 59			continue;
 60		}
 61		if (test_clear_buffer_dirty(bh)) {
 62			mark_buffer_async_write(bh);
 63		} else {
 64			unlock_buffer(bh);
 65		}
 66	} while ((bh = bh->b_this_page) != head);
 67
 68	/*
 69	 * The page and its buffers are protected by PageWriteback(), so we can
 70	 * drop the bh refcounts early.
 71	 */
 72	BUG_ON(PageWriteback(page));
 73	set_page_writeback(page);
 74
 75	do {
 76		struct buffer_head *next = bh->b_this_page;
 77		if (buffer_async_write(bh)) {
 78			submit_bh(REQ_OP_WRITE | write_flags, bh);
 79			nr_underway++;
 80		}
 81		bh = next;
 82	} while (bh != head);
 83	unlock_page(page);
 84
 85	if (nr_underway == 0)
 86		end_page_writeback(page);
 87
 88	return 0;
 89}
 90
 91const struct address_space_operations gfs2_meta_aops = {
 92	.dirty_folio	= block_dirty_folio,
 93	.invalidate_folio = block_invalidate_folio,
 94	.writepage = gfs2_aspace_writepage,
 95	.release_folio = gfs2_release_folio,
 96};
 97
 98const struct address_space_operations gfs2_rgrp_aops = {
 99	.dirty_folio	= block_dirty_folio,
100	.invalidate_folio = block_invalidate_folio,
101	.writepage = gfs2_aspace_writepage,
102	.release_folio = gfs2_release_folio,
103};
104
105/**
106 * gfs2_getbuf - Get a buffer with a given address space
107 * @gl: the glock
108 * @blkno: the block number (filesystem scope)
109 * @create: 1 if the buffer should be created
110 *
111 * Returns: the buffer
112 */
113
114struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
115{
116	struct address_space *mapping = gfs2_glock2aspace(gl);
117	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
118	struct page *page;
119	struct buffer_head *bh;
120	unsigned int shift;
121	unsigned long index;
122	unsigned int bufnum;
123
124	if (mapping == NULL)
125		mapping = &sdp->sd_aspace;
126
127	shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
128	index = blkno >> shift;             /* convert block to page */
129	bufnum = blkno - (index << shift);  /* block buf index within page */
130
131	if (create) {
132		for (;;) {
133			page = grab_cache_page(mapping, index);
134			if (page)
135				break;
136			yield();
137		}
138		if (!page_has_buffers(page))
139			create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
140	} else {
141		page = find_get_page_flags(mapping, index,
142						FGP_LOCK|FGP_ACCESSED);
143		if (!page)
144			return NULL;
145		if (!page_has_buffers(page)) {
146			bh = NULL;
147			goto out_unlock;
148		}
149	}
150
 
 
 
151	/* Locate header for our buffer within our page */
152	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
153		/* Do nothing */;
154	get_bh(bh);
155
156	if (!buffer_mapped(bh))
157		map_bh(bh, sdp->sd_vfs, blkno);
158
159out_unlock:
160	unlock_page(page);
161	put_page(page);
162
163	return bh;
164}
165
166static void meta_prep_new(struct buffer_head *bh)
167{
168	struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
169
170	lock_buffer(bh);
171	clear_buffer_dirty(bh);
172	set_buffer_uptodate(bh);
173	unlock_buffer(bh);
174
175	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
176}
177
178/**
179 * gfs2_meta_new - Get a block
180 * @gl: The glock associated with this block
181 * @blkno: The block number
182 *
183 * Returns: The buffer
184 */
185
186struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
187{
188	struct buffer_head *bh;
189	bh = gfs2_getbuf(gl, blkno, CREATE);
190	meta_prep_new(bh);
191	return bh;
192}
193
194static void gfs2_meta_read_endio(struct bio *bio)
195{
196	struct bio_vec *bvec;
197	struct bvec_iter_all iter_all;
198
199	bio_for_each_segment_all(bvec, bio, iter_all) {
200		struct page *page = bvec->bv_page;
201		struct buffer_head *bh = page_buffers(page);
202		unsigned int len = bvec->bv_len;
203
204		while (bh_offset(bh) < bvec->bv_offset)
205			bh = bh->b_this_page;
206		do {
207			struct buffer_head *next = bh->b_this_page;
208			len -= bh->b_size;
209			bh->b_end_io(bh, !bio->bi_status);
210			bh = next;
211		} while (bh && len);
212	}
213	bio_put(bio);
214}
215
216/*
217 * Submit several consecutive buffer head I/O requests as a single bio I/O
218 * request.  (See submit_bh_wbc.)
219 */
220static void gfs2_submit_bhs(blk_opf_t opf, struct buffer_head *bhs[], int num)
221{
222	while (num > 0) {
223		struct buffer_head *bh = *bhs;
224		struct bio *bio;
225
226		bio = bio_alloc(bh->b_bdev, num, opf, GFP_NOIO);
227		bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
228		while (num > 0) {
229			bh = *bhs;
230			if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
231				BUG_ON(bio->bi_iter.bi_size == 0);
232				break;
233			}
234			bhs++;
235			num--;
236		}
237		bio->bi_end_io = gfs2_meta_read_endio;
238		submit_bio(bio);
239	}
 
 
240}
241
242/**
243 * gfs2_meta_read - Read a block from disk
244 * @gl: The glock covering the block
245 * @blkno: The block number
246 * @flags: flags
247 * @rahead: Do read-ahead
248 * @bhp: the place where the buffer is returned (NULL on failure)
249 *
250 * Returns: errno
251 */
252
253int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
254		   int rahead, struct buffer_head **bhp)
255{
256	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
257	struct buffer_head *bh, *bhs[2];
258	int num = 0;
259
260	if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp)) {
261		*bhp = NULL;
262		return -EIO;
263	}
264
265	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
266
267	lock_buffer(bh);
268	if (buffer_uptodate(bh)) {
269		unlock_buffer(bh);
270		flags &= ~DIO_WAIT;
271	} else {
272		bh->b_end_io = end_buffer_read_sync;
273		get_bh(bh);
274		bhs[num++] = bh;
275	}
276
277	if (rahead) {
278		bh = gfs2_getbuf(gl, blkno + 1, CREATE);
279
280		lock_buffer(bh);
281		if (buffer_uptodate(bh)) {
282			unlock_buffer(bh);
283			brelse(bh);
284		} else {
285			bh->b_end_io = end_buffer_read_sync;
286			bhs[num++] = bh;
287		}
288	}
289
290	gfs2_submit_bhs(REQ_OP_READ | REQ_META | REQ_PRIO, bhs, num);
291	if (!(flags & DIO_WAIT))
292		return 0;
293
294	bh = *bhp;
295	wait_on_buffer(bh);
296	if (unlikely(!buffer_uptodate(bh))) {
297		struct gfs2_trans *tr = current->journal_info;
298		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
299			gfs2_io_error_bh_wd(sdp, bh);
300		brelse(bh);
301		*bhp = NULL;
302		return -EIO;
303	}
304
305	return 0;
306}
307
308/**
309 * gfs2_meta_wait - Reread a block from disk
310 * @sdp: the filesystem
311 * @bh: The block to wait for
312 *
313 * Returns: errno
314 */
315
316int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
317{
318	if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp))
319		return -EIO;
320
321	wait_on_buffer(bh);
322
323	if (!buffer_uptodate(bh)) {
324		struct gfs2_trans *tr = current->journal_info;
325		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
326			gfs2_io_error_bh_wd(sdp, bh);
327		return -EIO;
328	}
329	if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp))
330		return -EIO;
331
332	return 0;
333}
334
335void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
336{
337	struct address_space *mapping = bh->b_page->mapping;
338	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
339	struct gfs2_bufdata *bd = bh->b_private;
340	struct gfs2_trans *tr = current->journal_info;
341	int was_pinned = 0;
342
343	if (test_clear_buffer_pinned(bh)) {
344		trace_gfs2_pin(bd, 0);
345		atomic_dec(&sdp->sd_log_pinned);
346		list_del_init(&bd->bd_list);
347		if (meta == REMOVE_META)
348			tr->tr_num_buf_rm++;
349		else
350			tr->tr_num_databuf_rm++;
351		set_bit(TR_TOUCHED, &tr->tr_flags);
352		was_pinned = 1;
353		brelse(bh);
354	}
355	if (bd) {
 
356		if (bd->bd_tr) {
357			gfs2_trans_add_revoke(sdp, bd);
358		} else if (was_pinned) {
359			bh->b_private = NULL;
360			kmem_cache_free(gfs2_bufdata_cachep, bd);
361		} else if (!list_empty(&bd->bd_ail_st_list) &&
362					!list_empty(&bd->bd_ail_gl_list)) {
363			gfs2_remove_from_ail(bd);
364		}
 
365	}
366	clear_buffer_dirty(bh);
367	clear_buffer_uptodate(bh);
368}
369
370/**
371 * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list
372 * @sdp: superblock
373 * @bstart: starting block address of buffers to remove
374 * @blen: length of buffers to be removed
375 *
376 * This function is called from gfs2_journal wipe, whose job is to remove
377 * buffers, corresponding to deleted blocks, from the journal. If we find any
378 * bufdata elements on the system ail1 list, they haven't been written to
379 * the journal yet. So we remove them.
380 */
381static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen)
382{
383	struct gfs2_trans *tr, *s;
384	struct gfs2_bufdata *bd, *bs;
385	struct buffer_head *bh;
386	u64 end = bstart + blen;
387
388	gfs2_log_lock(sdp);
389	spin_lock(&sdp->sd_ail_lock);
390	list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) {
391		list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list,
392					 bd_ail_st_list) {
393			bh = bd->bd_bh;
394			if (bh->b_blocknr < bstart || bh->b_blocknr >= end)
395				continue;
396
397			gfs2_remove_from_journal(bh, REMOVE_JDATA);
398		}
399	}
400	spin_unlock(&sdp->sd_ail_lock);
401	gfs2_log_unlock(sdp);
402}
403
404static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
405{
406	struct address_space *mapping = ip->i_inode.i_mapping;
407	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
408	struct page *page;
409	struct buffer_head *bh;
410	unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
411	unsigned long index = blkno >> shift; /* convert block to page */
412	unsigned int bufnum = blkno - (index << shift);
413
414	page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
415	if (!page)
416		return NULL;
417	if (!page_has_buffers(page)) {
418		unlock_page(page);
419		put_page(page);
420		return NULL;
421	}
422	/* Locate header for our buffer within our page */
423	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
424		/* Do nothing */;
425	get_bh(bh);
426	unlock_page(page);
427	put_page(page);
428	return bh;
429}
430
431/**
432 * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore
433 * @ip: the inode who owns the buffers
434 * @bstart: the first buffer in the run
435 * @blen: the number of buffers in the run
436 *
437 */
438
439void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
440{
441	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
442	struct buffer_head *bh;
443	int ty;
444
445	if (!ip->i_gl) {
446		/* This can only happen during incomplete inode creation. */
447		BUG_ON(!test_bit(GIF_ALLOC_FAILED, &ip->i_flags));
448		return;
449	}
450
451	gfs2_ail1_wipe(sdp, bstart, blen);
452	while (blen) {
453		ty = REMOVE_META;
454		bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
455		if (!bh && gfs2_is_jdata(ip)) {
456			bh = gfs2_getjdatabuf(ip, bstart);
457			ty = REMOVE_JDATA;
458		}
459		if (bh) {
460			lock_buffer(bh);
461			gfs2_log_lock(sdp);
462			spin_lock(&sdp->sd_ail_lock);
463			gfs2_remove_from_journal(bh, ty);
464			spin_unlock(&sdp->sd_ail_lock);
465			gfs2_log_unlock(sdp);
466			unlock_buffer(bh);
467			brelse(bh);
468		}
469
470		bstart++;
471		blen--;
472	}
473}
474
475/**
476 * gfs2_meta_buffer - Get a metadata buffer
477 * @ip: The GFS2 inode
478 * @mtype: The block type (GFS2_METATYPE_*)
479 * @num: The block number (device relative) of the buffer
480 * @bhp: the buffer is returned here
481 *
482 * Returns: errno
483 */
484
485int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
486		     struct buffer_head **bhp)
487{
488	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
489	struct gfs2_glock *gl = ip->i_gl;
490	struct buffer_head *bh;
491	int ret = 0;
 
492	int rahead = 0;
493
494	if (num == ip->i_no_addr)
495		rahead = ip->i_rahead;
496
497	ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
498	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
499		brelse(bh);
500		ret = -EIO;
501	} else {
502		*bhp = bh;
503	}
 
504	return ret;
505}
506
507/**
508 * gfs2_meta_ra - start readahead on an extent of a file
509 * @gl: the glock the blocks belong to
510 * @dblock: the starting disk block
511 * @extlen: the number of blocks in the extent
512 *
513 * returns: the first buffer in the extent
514 */
515
516struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
517{
518	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
519	struct buffer_head *first_bh, *bh;
520	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
521			  sdp->sd_sb.sb_bsize_shift;
522
523	BUG_ON(!extlen);
524
525	if (max_ra < 1)
526		max_ra = 1;
527	if (extlen > max_ra)
528		extlen = max_ra;
529
530	first_bh = gfs2_getbuf(gl, dblock, CREATE);
531
532	if (buffer_uptodate(first_bh))
533		goto out;
534	bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
 
535
536	dblock++;
537	extlen--;
538
539	while (extlen) {
540		bh = gfs2_getbuf(gl, dblock, CREATE);
541
542		bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
 
543		brelse(bh);
544		dblock++;
545		extlen--;
546		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
547			goto out;
548	}
549
550	wait_on_buffer(first_bh);
551out:
552	return first_bh;
553}
554
v4.6
 
  1/*
  2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
  3 * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
  4 *
  5 * This copyrighted material is made available to anyone wishing to use,
  6 * modify, copy, or redistribute it subject to the terms and conditions
  7 * of the GNU General Public License version 2.
  8 */
  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>
 20#include <linux/bio.h>
 21#include <linux/gfs2_ondisk.h>
 22
 23#include "gfs2.h"
 24#include "incore.h"
 25#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"
 33#include "util.h"
 34#include "trace_gfs2.h"
 35
 36static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
 37{
 38	struct buffer_head *bh, *head;
 39	int nr_underway = 0;
 40	int write_op = REQ_META | REQ_PRIO |
 41		(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
 42
 43	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
 55		 * potentially cause a busy-wait loop from flusher thread and kswapd
 56		 * activity, but those code paths have their own higher-level
 57		 * throttling.
 58		 */
 59		if (wbc->sync_mode != WB_SYNC_NONE) {
 60			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
 89	if (nr_underway == 0)
 90		end_page_writeback(page);
 91
 92	return 0;
 93}
 94
 95const struct address_space_operations gfs2_meta_aops = {
 
 
 96	.writepage = gfs2_aspace_writepage,
 97	.releasepage = gfs2_releasepage,
 98};
 99
100const struct address_space_operations gfs2_rgrp_aops = {
 
 
101	.writepage = gfs2_aspace_writepage,
102	.releasepage = gfs2_releasepage,
103};
104
105/**
106 * gfs2_getbuf - Get a buffer with a given address space
107 * @gl: the glock
108 * @blkno: the block number (filesystem scope)
109 * @create: 1 if the buffer should be created
110 *
111 * Returns: the buffer
112 */
113
114struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
115{
116	struct address_space *mapping = gfs2_glock2aspace(gl);
117	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
118	struct page *page;
119	struct buffer_head *bh;
120	unsigned int shift;
121	unsigned long index;
122	unsigned int bufnum;
123
124	if (mapping == NULL)
125		mapping = &sdp->sd_aspace;
126
127	shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
128	index = blkno >> shift;             /* convert block to page */
129	bufnum = blkno - (index << shift);  /* block buf index within page */
130
131	if (create) {
132		for (;;) {
133			page = grab_cache_page(mapping, index);
134			if (page)
135				break;
136			yield();
137		}
 
 
138	} else {
139		page = find_get_page_flags(mapping, index,
140						FGP_LOCK|FGP_ACCESSED);
141		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);
157	put_page(page);
158
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
182struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
183{
184	struct buffer_head *bh;
185	bh = gfs2_getbuf(gl, blkno, CREATE);
186	meta_prep_new(bh);
187	return bh;
188}
189
190static void gfs2_meta_read_endio(struct bio *bio)
191{
192	struct bio_vec *bvec;
193	int i;
194
195	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);
208	}
209	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 */
216static void gfs2_submit_bhs(int rw, struct buffer_head *bhs[], int num)
217{
218	struct buffer_head *bh = bhs[0];
219	struct bio *bio;
220	int i;
221
222	if (!num)
223		return;
224
225	bio = bio_alloc(GFP_NOIO, num);
226	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
227	bio->bi_bdev = bh->b_bdev;
228	for (i = 0; i < num; i++) {
229		bh = bhs[i];
230		bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
 
 
 
 
231	}
232	bio->bi_end_io = gfs2_meta_read_endio;
233	submit_bio(rw, bio);
234}
235
236/**
237 * gfs2_meta_read - Read a block from disk
238 * @gl: The glock covering the block
239 * @blkno: The block number
240 * @flags: flags
 
241 * @bhp: the place where the buffer is returned (NULL on failure)
242 *
243 * Returns: errno
244 */
245
246int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
247		   int rahead, struct buffer_head **bhp)
248{
249	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
250	struct buffer_head *bh, *bhs[2];
251	int num = 0;
252
253	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
254		*bhp = NULL;
255		return -EIO;
256	}
257
258	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
259
260	lock_buffer(bh);
261	if (buffer_uptodate(bh)) {
262		unlock_buffer(bh);
263		flags &= ~DIO_WAIT;
264	} else {
265		bh->b_end_io = end_buffer_read_sync;
266		get_bh(bh);
267		bhs[num++] = bh;
268	}
269
270	if (rahead) {
271		bh = gfs2_getbuf(gl, blkno + 1, CREATE);
272
273		lock_buffer(bh);
274		if (buffer_uptodate(bh)) {
275			unlock_buffer(bh);
276			brelse(bh);
277		} else {
278			bh->b_end_io = end_buffer_read_sync;
279			bhs[num++] = bh;
280		}
281	}
282
283	gfs2_submit_bhs(READ_SYNC | REQ_META | REQ_PRIO, bhs, num);
284	if (!(flags & DIO_WAIT))
285		return 0;
286
287	bh = *bhp;
288	wait_on_buffer(bh);
289	if (unlikely(!buffer_uptodate(bh))) {
290		struct gfs2_trans *tr = current->journal_info;
291		if (tr && tr->tr_touched)
292			gfs2_io_error_bh(sdp, bh);
293		brelse(bh);
294		*bhp = NULL;
295		return -EIO;
296	}
297
298	return 0;
299}
300
301/**
302 * gfs2_meta_wait - Reread a block from disk
303 * @sdp: the filesystem
304 * @bh: The block to wait for
305 *
306 * Returns: errno
307 */
308
309int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
310{
311	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
312		return -EIO;
313
314	wait_on_buffer(bh);
315
316	if (!buffer_uptodate(bh)) {
317		struct gfs2_trans *tr = current->journal_info;
318		if (tr && tr->tr_touched)
319			gfs2_io_error_bh(sdp, bh);
320		return -EIO;
321	}
322	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
323		return -EIO;
324
325	return 0;
326}
327
328void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
329{
330	struct address_space *mapping = bh->b_page->mapping;
331	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
332	struct gfs2_bufdata *bd = bh->b_private;
 
333	int was_pinned = 0;
334
335	if (test_clear_buffer_pinned(bh)) {
336		trace_gfs2_pin(bd, 0);
337		atomic_dec(&sdp->sd_log_pinned);
338		list_del_init(&bd->bd_list);
339		if (meta)
340			tr->tr_num_buf_rm++;
341		else
342			tr->tr_num_databuf_rm++;
343		tr->tr_touched = 1;
344		was_pinned = 1;
345		brelse(bh);
346	}
347	if (bd) {
348		spin_lock(&sdp->sd_ail_lock);
349		if (bd->bd_tr) {
350			gfs2_trans_add_revoke(sdp, bd);
351		} else if (was_pinned) {
352			bh->b_private = NULL;
353			kmem_cache_free(gfs2_bufdata_cachep, bd);
 
 
 
354		}
355		spin_unlock(&sdp->sd_ail_lock);
356	}
357	clear_buffer_dirty(bh);
358	clear_buffer_uptodate(bh);
359}
360
361/**
362 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
363 * @ip: the inode who owns the buffers
364 * @bstart: the first buffer in the run
365 * @blen: the number of buffers in the run
366 *
367 */
368
369void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
370{
371	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
372	struct buffer_head *bh;
 
373
 
 
 
 
 
 
 
374	while (blen) {
 
375		bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 
 
 
 
376		if (bh) {
377			lock_buffer(bh);
378			gfs2_log_lock(sdp);
379			gfs2_remove_from_journal(bh, current->journal_info, 1);
 
 
380			gfs2_log_unlock(sdp);
381			unlock_buffer(bh);
382			brelse(bh);
383		}
384
385		bstart++;
386		blen--;
387	}
388}
389
390/**
391 * gfs2_meta_indirect_buffer - Get a metadata buffer
392 * @ip: The GFS2 inode
393 * @height: The level of this buf in the metadata (indir addr) tree (if any)
394 * @num: The block number (device relative) of the buffer
395 * @bhp: the buffer is returned here
396 *
397 * Returns: errno
398 */
399
400int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
401			      struct buffer_head **bhp)
402{
403	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
404	struct gfs2_glock *gl = ip->i_gl;
405	struct buffer_head *bh;
406	int ret = 0;
407	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
408	int rahead = 0;
409
410	if (num == ip->i_no_addr)
411		rahead = ip->i_rahead;
412
413	ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
414	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
415		brelse(bh);
416		ret = -EIO;
 
 
417	}
418	*bhp = bh;
419	return ret;
420}
421
422/**
423 * gfs2_meta_ra - start readahead on an extent of a file
424 * @gl: the glock the blocks belong to
425 * @dblock: the starting disk block
426 * @extlen: the number of blocks in the extent
427 *
428 * returns: the first buffer in the extent
429 */
430
431struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
432{
433	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
434	struct buffer_head *first_bh, *bh;
435	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
436			  sdp->sd_sb.sb_bsize_shift;
437
438	BUG_ON(!extlen);
439
440	if (max_ra < 1)
441		max_ra = 1;
442	if (extlen > max_ra)
443		extlen = max_ra;
444
445	first_bh = gfs2_getbuf(gl, dblock, CREATE);
446
447	if (buffer_uptodate(first_bh))
448		goto out;
449	if (!buffer_locked(first_bh))
450		ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
451
452	dblock++;
453	extlen--;
454
455	while (extlen) {
456		bh = gfs2_getbuf(gl, dblock, CREATE);
457
458		if (!buffer_uptodate(bh) && !buffer_locked(bh))
459			ll_rw_block(READA | REQ_META, 1, &bh);
460		brelse(bh);
461		dblock++;
462		extlen--;
463		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
464			goto out;
465	}
466
467	wait_on_buffer(first_bh);
468out:
469	return first_bh;
470}
471