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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
v4.17
 
  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_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc);
 41
 42	BUG_ON(!PageLocked(page));
 43	BUG_ON(!page_has_buffers(page));
 44
 45	head = page_buffers(page);
 46	bh = head;
 47
 48	do {
 49		if (!buffer_mapped(bh))
 50			continue;
 51		/*
 52		 * If it's a fully non-blocking write attempt and we cannot
 53		 * lock the buffer then redirty the page.  Note that this can
 54		 * potentially cause a busy-wait loop from flusher thread and kswapd
 55		 * activity, but those code paths have their own higher-level
 56		 * throttling.
 57		 */
 58		if (wbc->sync_mode != WB_SYNC_NONE) {
 59			lock_buffer(bh);
 60		} else if (!trylock_buffer(bh)) {
 61			redirty_page_for_writepage(wbc, page);
 62			continue;
 63		}
 64		if (test_clear_buffer_dirty(bh)) {
 65			mark_buffer_async_write(bh);
 66		} else {
 67			unlock_buffer(bh);
 68		}
 69	} while ((bh = bh->b_this_page) != head);
 70
 71	/*
 72	 * The page and its buffers are protected by PageWriteback(), so we can
 73	 * drop the bh refcounts early.
 74	 */
 75	BUG_ON(PageWriteback(page));
 76	set_page_writeback(page);
 77
 78	do {
 79		struct buffer_head *next = bh->b_this_page;
 80		if (buffer_async_write(bh)) {
 81			submit_bh(REQ_OP_WRITE, write_flags, bh);
 82			nr_underway++;
 83		}
 84		bh = next;
 85	} while (bh != head);
 86	unlock_page(page);
 87
 88	if (nr_underway == 0)
 89		end_page_writeback(page);
 90
 91	return 0;
 92}
 93
 94const struct address_space_operations gfs2_meta_aops = {
 
 
 95	.writepage = gfs2_aspace_writepage,
 96	.releasepage = gfs2_releasepage,
 97};
 98
 99const struct address_space_operations gfs2_rgrp_aops = {
 
 
100	.writepage = gfs2_aspace_writepage,
101	.releasepage = gfs2_releasepage,
102};
103
104/**
105 * gfs2_getbuf - Get a buffer with a given address space
106 * @gl: the glock
107 * @blkno: the block number (filesystem scope)
108 * @create: 1 if the buffer should be created
109 *
110 * Returns: the buffer
111 */
112
113struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
114{
115	struct address_space *mapping = gfs2_glock2aspace(gl);
116	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
117	struct page *page;
118	struct buffer_head *bh;
119	unsigned int shift;
120	unsigned long index;
121	unsigned int bufnum;
122
123	if (mapping == NULL)
124		mapping = &sdp->sd_aspace;
125
126	shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
127	index = blkno >> shift;             /* convert block to page */
128	bufnum = blkno - (index << shift);  /* block buf index within page */
129
130	if (create) {
131		for (;;) {
132			page = grab_cache_page(mapping, index);
133			if (page)
134				break;
135			yield();
136		}
 
 
137	} else {
138		page = find_get_page_flags(mapping, index,
139						FGP_LOCK|FGP_ACCESSED);
140		if (!page)
141			return NULL;
 
 
 
 
142	}
143
144	if (!page_has_buffers(page))
145		create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
146
147	/* Locate header for our buffer within our page */
148	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
149		/* Do nothing */;
150	get_bh(bh);
151
152	if (!buffer_mapped(bh))
153		map_bh(bh, sdp->sd_vfs, blkno);
154
 
155	unlock_page(page);
156	put_page(page);
157
158	return bh;
159}
160
161static void meta_prep_new(struct buffer_head *bh)
162{
163	struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
164
165	lock_buffer(bh);
166	clear_buffer_dirty(bh);
167	set_buffer_uptodate(bh);
168	unlock_buffer(bh);
169
170	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
171}
172
173/**
174 * gfs2_meta_new - Get a block
175 * @gl: The glock associated with this block
176 * @blkno: The block number
177 *
178 * Returns: The buffer
179 */
180
181struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
182{
183	struct buffer_head *bh;
184	bh = gfs2_getbuf(gl, blkno, CREATE);
185	meta_prep_new(bh);
186	return bh;
187}
188
189static void gfs2_meta_read_endio(struct bio *bio)
190{
191	struct bio_vec *bvec;
192	int i;
193
194	bio_for_each_segment_all(bvec, bio, i) {
195		struct page *page = bvec->bv_page;
196		struct buffer_head *bh = page_buffers(page);
197		unsigned int len = bvec->bv_len;
198
199		while (bh_offset(bh) < bvec->bv_offset)
200			bh = bh->b_this_page;
201		do {
202			struct buffer_head *next = bh->b_this_page;
203			len -= bh->b_size;
204			bh->b_end_io(bh, !bio->bi_status);
205			bh = next;
206		} while (bh && len);
207	}
208	bio_put(bio);
209}
210
211/*
212 * Submit several consecutive buffer head I/O requests as a single bio I/O
213 * request.  (See submit_bh_wbc.)
214 */
215static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[],
216			    int num)
217{
218	while (num > 0) {
219		struct buffer_head *bh = *bhs;
220		struct bio *bio;
221
222		bio = bio_alloc(GFP_NOIO, num);
223		bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
224		bio_set_dev(bio, bh->b_bdev);
225		while (num > 0) {
226			bh = *bhs;
227			if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
228				BUG_ON(bio->bi_iter.bi_size == 0);
229				break;
230			}
231			bhs++;
232			num--;
233		}
234		bio->bi_end_io = gfs2_meta_read_endio;
235		bio_set_op_attrs(bio, op, op_flags);
236		submit_bio(bio);
237	}
238}
239
240/**
241 * gfs2_meta_read - Read a block from disk
242 * @gl: The glock covering the block
243 * @blkno: The block number
244 * @flags: flags
 
245 * @bhp: the place where the buffer is returned (NULL on failure)
246 *
247 * Returns: errno
248 */
249
250int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
251		   int rahead, struct buffer_head **bhp)
252{
253	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
254	struct buffer_head *bh, *bhs[2];
255	int num = 0;
256
257	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
258		*bhp = NULL;
259		return -EIO;
260	}
261
262	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
263
264	lock_buffer(bh);
265	if (buffer_uptodate(bh)) {
266		unlock_buffer(bh);
267		flags &= ~DIO_WAIT;
268	} else {
269		bh->b_end_io = end_buffer_read_sync;
270		get_bh(bh);
271		bhs[num++] = bh;
272	}
273
274	if (rahead) {
275		bh = gfs2_getbuf(gl, blkno + 1, CREATE);
276
277		lock_buffer(bh);
278		if (buffer_uptodate(bh)) {
279			unlock_buffer(bh);
280			brelse(bh);
281		} else {
282			bh->b_end_io = end_buffer_read_sync;
283			bhs[num++] = bh;
284		}
285	}
286
287	gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num);
288	if (!(flags & DIO_WAIT))
289		return 0;
290
291	bh = *bhp;
292	wait_on_buffer(bh);
293	if (unlikely(!buffer_uptodate(bh))) {
294		struct gfs2_trans *tr = current->journal_info;
295		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
296			gfs2_io_error_bh(sdp, bh);
297		brelse(bh);
298		*bhp = NULL;
299		return -EIO;
300	}
301
302	return 0;
303}
304
305/**
306 * gfs2_meta_wait - Reread a block from disk
307 * @sdp: the filesystem
308 * @bh: The block to wait for
309 *
310 * Returns: errno
311 */
312
313int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
314{
315	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
316		return -EIO;
317
318	wait_on_buffer(bh);
319
320	if (!buffer_uptodate(bh)) {
321		struct gfs2_trans *tr = current->journal_info;
322		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
323			gfs2_io_error_bh(sdp, bh);
324		return -EIO;
325	}
326	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
327		return -EIO;
328
329	return 0;
330}
331
332void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
333{
334	struct address_space *mapping = bh->b_page->mapping;
335	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
336	struct gfs2_bufdata *bd = bh->b_private;
337	struct gfs2_trans *tr = current->journal_info;
338	int was_pinned = 0;
339
340	if (test_clear_buffer_pinned(bh)) {
341		trace_gfs2_pin(bd, 0);
342		atomic_dec(&sdp->sd_log_pinned);
343		list_del_init(&bd->bd_list);
344		if (meta == REMOVE_META)
345			tr->tr_num_buf_rm++;
346		else
347			tr->tr_num_databuf_rm++;
348		set_bit(TR_TOUCHED, &tr->tr_flags);
349		was_pinned = 1;
350		brelse(bh);
351	}
352	if (bd) {
353		spin_lock(&sdp->sd_ail_lock);
354		if (bd->bd_tr) {
355			gfs2_trans_add_revoke(sdp, bd);
356		} else if (was_pinned) {
357			bh->b_private = NULL;
358			kmem_cache_free(gfs2_bufdata_cachep, bd);
 
 
 
359		}
360		spin_unlock(&sdp->sd_ail_lock);
361	}
362	clear_buffer_dirty(bh);
363	clear_buffer_uptodate(bh);
364}
365
366/**
367 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
368 * @ip: the inode who owns the buffers
369 * @bstart: the first buffer in the run
370 * @blen: the number of buffers in the run
371 *
372 */
373
374void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
375{
376	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
377	struct buffer_head *bh;
 
378
 
 
 
 
 
 
 
379	while (blen) {
 
380		bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 
 
 
 
381		if (bh) {
382			lock_buffer(bh);
383			gfs2_log_lock(sdp);
384			gfs2_remove_from_journal(bh, REMOVE_META);
 
 
385			gfs2_log_unlock(sdp);
386			unlock_buffer(bh);
387			brelse(bh);
388		}
389
390		bstart++;
391		blen--;
392	}
393}
394
395/**
396 * gfs2_meta_indirect_buffer - Get a metadata buffer
397 * @ip: The GFS2 inode
398 * @height: The level of this buf in the metadata (indir addr) tree (if any)
399 * @num: The block number (device relative) of the buffer
400 * @bhp: the buffer is returned here
401 *
402 * Returns: errno
403 */
404
405int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
406			      struct buffer_head **bhp)
407{
408	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
409	struct gfs2_glock *gl = ip->i_gl;
410	struct buffer_head *bh;
411	int ret = 0;
412	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
413	int rahead = 0;
414
415	if (num == ip->i_no_addr)
416		rahead = ip->i_rahead;
417
418	ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
419	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
420		brelse(bh);
421		ret = -EIO;
422	} else {
423		*bhp = bh;
424	}
425	return ret;
426}
427
428/**
429 * gfs2_meta_ra - start readahead on an extent of a file
430 * @gl: the glock the blocks belong to
431 * @dblock: the starting disk block
432 * @extlen: the number of blocks in the extent
433 *
434 * returns: the first buffer in the extent
435 */
436
437struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
438{
439	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
440	struct buffer_head *first_bh, *bh;
441	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
442			  sdp->sd_sb.sb_bsize_shift;
443
444	BUG_ON(!extlen);
445
446	if (max_ra < 1)
447		max_ra = 1;
448	if (extlen > max_ra)
449		extlen = max_ra;
450
451	first_bh = gfs2_getbuf(gl, dblock, CREATE);
452
453	if (buffer_uptodate(first_bh))
454		goto out;
455	if (!buffer_locked(first_bh))
456		ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh);
457
458	dblock++;
459	extlen--;
460
461	while (extlen) {
462		bh = gfs2_getbuf(gl, dblock, CREATE);
463
464		if (!buffer_uptodate(bh) && !buffer_locked(bh))
465			ll_rw_block(REQ_OP_READ,
466				    REQ_RAHEAD | REQ_META | REQ_PRIO,
467				    1, &bh);
468		brelse(bh);
469		dblock++;
470		extlen--;
471		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
472			goto out;
473	}
474
475	wait_on_buffer(first_bh);
476out:
477	return first_bh;
478}
479