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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
v3.5.6
  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 pdflush 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
100/**
101 * gfs2_meta_sync - Sync all buffers associated with a glock
102 * @gl: The glock
103 *
104 */
105
106void gfs2_meta_sync(struct gfs2_glock *gl)
107{
108	struct address_space *mapping = gfs2_glock2aspace(gl);
109	int error;
110
111	filemap_fdatawrite(mapping);
112	error = filemap_fdatawait(mapping);
113
114	if (error)
115		gfs2_io_error(gl->gl_sbd);
116}
117
118/**
119 * gfs2_getbuf - Get a buffer with a given address space
120 * @gl: the glock
121 * @blkno: the block number (filesystem scope)
122 * @create: 1 if the buffer should be created
123 *
124 * Returns: the buffer
125 */
126
127struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
128{
129	struct address_space *mapping = gfs2_glock2aspace(gl);
130	struct gfs2_sbd *sdp = gl->gl_sbd;
131	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 (;;) {
143			page = grab_cache_page(mapping, index);
144			if (page)
145				break;
146			yield();
147		}
148	} else {
149		page = find_lock_page(mapping, index);
 
150		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
192struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
193{
194	struct buffer_head *bh;
195	bh = gfs2_getbuf(gl, blkno, CREATE);
196	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
204 * @flags: flags
205 * @bhp: the place where the buffer is returned (NULL on failure)
206 *
207 * Returns: errno
208 */
209
210int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
211		   struct buffer_head **bhp)
212{
213	struct gfs2_sbd *sdp = gl->gl_sbd;
214	struct buffer_head *bh;
 
215
216	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 
217		return -EIO;
 
218
219	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
220
221	lock_buffer(bh);
222	if (buffer_uptodate(bh)) {
223		unlock_buffer(bh);
224		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
225	}
226	bh->b_end_io = end_buffer_read_sync;
227	get_bh(bh);
228	submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh);
229	if (!(flags & DIO_WAIT))
230		return 0;
231
 
232	wait_on_buffer(bh);
233	if (unlikely(!buffer_uptodate(bh))) {
234		struct gfs2_trans *tr = current->journal_info;
235		if (tr && tr->tr_touched)
236			gfs2_io_error_bh(sdp, bh);
237		brelse(bh);
 
238		return -EIO;
239	}
240
241	return 0;
242}
243
244/**
245 * gfs2_meta_wait - Reread a block from disk
246 * @sdp: the filesystem
247 * @bh: The block to wait for
248 *
249 * Returns: errno
250 */
251
252int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
253{
254	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
255		return -EIO;
256
257	wait_on_buffer(bh);
258
259	if (!buffer_uptodate(bh)) {
260		struct gfs2_trans *tr = current->journal_info;
261		if (tr && tr->tr_touched)
262			gfs2_io_error_bh(sdp, bh);
263		return -EIO;
264	}
265	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
266		return -EIO;
267
268	return 0;
269}
270
271/**
272 * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
273 * @gl: the glock the buffer belongs to
274 * @bh: The buffer to be attached to
275 * @meta: Flag to indicate whether its metadata or not
276 */
277
278void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
279			 int meta)
280{
281	struct gfs2_bufdata *bd;
282
283	if (meta)
284		lock_page(bh->b_page);
285
286	if (bh->b_private) {
287		if (meta)
288			unlock_page(bh->b_page);
289		return;
290	}
291
292	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
293	bd->bd_bh = bh;
294	bd->bd_gl = gl;
295
296	if (meta)
297		lops_init_le(bd, &gfs2_buf_lops);
298	else
299		lops_init_le(bd, &gfs2_databuf_lops);
300	bh->b_private = bd;
301
302	if (meta)
303		unlock_page(bh->b_page);
304}
305
306void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
307{
308	struct address_space *mapping = bh->b_page->mapping;
309	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
310	struct gfs2_bufdata *bd = bh->b_private;
 
 
311
312	if (test_clear_buffer_pinned(bh)) {
313		trace_gfs2_pin(bd, 0);
314		atomic_dec(&sdp->sd_log_pinned);
315		list_del_init(&bd->bd_list);
316		if (meta) {
317			gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
318			sdp->sd_log_num_buf--;
319			tr->tr_num_buf_rm++;
320		} else {
321			gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
322			sdp->sd_log_num_databuf--;
323			tr->tr_num_databuf_rm++;
324		}
325		tr->tr_touched = 1;
326		brelse(bh);
327	}
328	if (bd) {
329		spin_lock(&sdp->sd_ail_lock);
330		if (bd->bd_ail) {
331			gfs2_remove_from_ail(bd);
 
332			bh->b_private = NULL;
333			bd->bd_bh = NULL;
334			bd->bd_blkno = bh->b_blocknr;
335			gfs2_trans_add_revoke(sdp, bd);
336		}
337		spin_unlock(&sdp->sd_ail_lock);
338	}
339	clear_buffer_dirty(bh);
340	clear_buffer_uptodate(bh);
341}
342
343/**
344 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
345 * @ip: the inode who owns the buffers
346 * @bstart: the first buffer in the run
347 * @blen: the number of buffers in the run
348 *
349 */
350
351void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
352{
353	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
354	struct buffer_head *bh;
355
356	while (blen) {
357		bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
358		if (bh) {
359			lock_buffer(bh);
360			gfs2_log_lock(sdp);
361			gfs2_remove_from_journal(bh, current->journal_info, 1);
362			gfs2_log_unlock(sdp);
363			unlock_buffer(bh);
364			brelse(bh);
365		}
366
367		bstart++;
368		blen--;
369	}
370}
371
372/**
373 * gfs2_meta_indirect_buffer - Get a metadata buffer
374 * @ip: The GFS2 inode
375 * @height: The level of this buf in the metadata (indir addr) tree (if any)
376 * @num: The block number (device relative) of the buffer
377 * @bhp: the buffer is returned here
378 *
379 * Returns: errno
380 */
381
382int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
383			      struct buffer_head **bhp)
384{
385	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
386	struct gfs2_glock *gl = ip->i_gl;
387	struct buffer_head *bh;
388	int ret = 0;
389	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
 
 
 
 
390
391	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
392	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
393		brelse(bh);
394		ret = -EIO;
 
 
395	}
396	*bhp = bh;
397	return ret;
398}
399
400/**
401 * gfs2_meta_ra - start readahead on an extent of a file
402 * @gl: the glock the blocks belong to
403 * @dblock: the starting disk block
404 * @extlen: the number of blocks in the extent
405 *
406 * returns: the first buffer in the extent
407 */
408
409struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
410{
411	struct gfs2_sbd *sdp = gl->gl_sbd;
412	struct buffer_head *first_bh, *bh;
413	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
414			  sdp->sd_sb.sb_bsize_shift;
415
416	BUG_ON(!extlen);
417
418	if (max_ra < 1)
419		max_ra = 1;
420	if (extlen > max_ra)
421		extlen = max_ra;
422
423	first_bh = gfs2_getbuf(gl, dblock, CREATE);
424
425	if (buffer_uptodate(first_bh))
426		goto out;
427	if (!buffer_locked(first_bh))
428		ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
429
430	dblock++;
431	extlen--;
432
433	while (extlen) {
434		bh = gfs2_getbuf(gl, dblock, CREATE);
435
436		if (!buffer_uptodate(bh) && !buffer_locked(bh))
437			ll_rw_block(READA | REQ_META, 1, &bh);
 
 
438		brelse(bh);
439		dblock++;
440		extlen--;
441		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
442			goto out;
443	}
444
445	wait_on_buffer(first_bh);
446out:
447	return first_bh;
448}
449