xref: /openbmc/linux/fs/gfs2/meta_io.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 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 #include <linux/lm_interface.h>
23 
24 #include "gfs2.h"
25 #include "incore.h"
26 #include "glock.h"
27 #include "glops.h"
28 #include "inode.h"
29 #include "log.h"
30 #include "lops.h"
31 #include "meta_io.h"
32 #include "rgrp.h"
33 #include "trans.h"
34 #include "util.h"
35 #include "ops_address.h"
36 
37 static int aspace_get_block(struct inode *inode, sector_t lblock,
38 			    struct buffer_head *bh_result, int create)
39 {
40 	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
41 	return -EOPNOTSUPP;
42 }
43 
44 static int gfs2_aspace_writepage(struct page *page,
45 				 struct writeback_control *wbc)
46 {
47 	return block_write_full_page(page, aspace_get_block, wbc);
48 }
49 
50 static const struct address_space_operations aspace_aops = {
51 	.writepage = gfs2_aspace_writepage,
52 	.releasepage = gfs2_releasepage,
53 };
54 
55 /**
56  * gfs2_aspace_get - Create and initialize a struct inode structure
57  * @sdp: the filesystem the aspace is in
58  *
59  * Right now a struct inode is just a struct inode.  Maybe Linux
60  * will supply a more lightweight address space construct (that works)
61  * in the future.
62  *
63  * Make sure pages/buffers in this aspace aren't in high memory.
64  *
65  * Returns: the aspace
66  */
67 
68 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
69 {
70 	struct inode *aspace;
71 
72 	aspace = new_inode(sdp->sd_vfs);
73 	if (aspace) {
74 		mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
75 		aspace->i_mapping->a_ops = &aspace_aops;
76 		aspace->i_size = ~0ULL;
77 		aspace->i_private = NULL;
78 		insert_inode_hash(aspace);
79 	}
80 	return aspace;
81 }
82 
83 void gfs2_aspace_put(struct inode *aspace)
84 {
85 	remove_inode_hash(aspace);
86 	iput(aspace);
87 }
88 
89 /**
90  * gfs2_meta_inval - Invalidate all buffers associated with a glock
91  * @gl: the glock
92  *
93  */
94 
95 void gfs2_meta_inval(struct gfs2_glock *gl)
96 {
97 	struct gfs2_sbd *sdp = gl->gl_sbd;
98 	struct inode *aspace = gl->gl_aspace;
99 	struct address_space *mapping = gl->gl_aspace->i_mapping;
100 
101 	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
102 
103 	atomic_inc(&aspace->i_writecount);
104 	truncate_inode_pages(mapping, 0);
105 	atomic_dec(&aspace->i_writecount);
106 
107 	gfs2_assert_withdraw(sdp, !mapping->nrpages);
108 }
109 
110 /**
111  * gfs2_meta_sync - Sync all buffers associated with a glock
112  * @gl: The glock
113  *
114  */
115 
116 void gfs2_meta_sync(struct gfs2_glock *gl)
117 {
118 	struct address_space *mapping = gl->gl_aspace->i_mapping;
119 	int error;
120 
121 	filemap_fdatawrite(mapping);
122 	error = filemap_fdatawait(mapping);
123 
124 	if (error)
125 		gfs2_io_error(gl->gl_sbd);
126 }
127 
128 /**
129  * getbuf - Get a buffer with a given address space
130  * @gl: the glock
131  * @blkno: the block number (filesystem scope)
132  * @create: 1 if the buffer should be created
133  *
134  * Returns: the buffer
135  */
136 
137 static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create)
138 {
139 	struct address_space *mapping = gl->gl_aspace->i_mapping;
140 	struct gfs2_sbd *sdp = gl->gl_sbd;
141 	struct page *page;
142 	struct buffer_head *bh;
143 	unsigned int shift;
144 	unsigned long index;
145 	unsigned int bufnum;
146 
147 	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
148 	index = blkno >> shift;             /* convert block to page */
149 	bufnum = blkno - (index << shift);  /* block buf index within page */
150 
151 	if (create) {
152 		for (;;) {
153 			page = grab_cache_page(mapping, index);
154 			if (page)
155 				break;
156 			yield();
157 		}
158 	} else {
159 		page = find_lock_page(mapping, index);
160 		if (!page)
161 			return NULL;
162 	}
163 
164 	if (!page_has_buffers(page))
165 		create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
166 
167 	/* Locate header for our buffer within our page */
168 	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
169 		/* Do nothing */;
170 	get_bh(bh);
171 
172 	if (!buffer_mapped(bh))
173 		map_bh(bh, sdp->sd_vfs, blkno);
174 
175 	unlock_page(page);
176 	mark_page_accessed(page);
177 	page_cache_release(page);
178 
179 	return bh;
180 }
181 
182 static void meta_prep_new(struct buffer_head *bh)
183 {
184 	struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
185 
186 	lock_buffer(bh);
187 	clear_buffer_dirty(bh);
188 	set_buffer_uptodate(bh);
189 	unlock_buffer(bh);
190 
191 	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
192 }
193 
194 /**
195  * gfs2_meta_new - Get a block
196  * @gl: The glock associated with this block
197  * @blkno: The block number
198  *
199  * Returns: The buffer
200  */
201 
202 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
203 {
204 	struct buffer_head *bh;
205 	bh = getbuf(gl, blkno, CREATE);
206 	meta_prep_new(bh);
207 	return bh;
208 }
209 
210 /**
211  * gfs2_meta_read - Read a block from disk
212  * @gl: The glock covering the block
213  * @blkno: The block number
214  * @flags: flags
215  * @bhp: the place where the buffer is returned (NULL on failure)
216  *
217  * Returns: errno
218  */
219 
220 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
221 		   struct buffer_head **bhp)
222 {
223 	*bhp = getbuf(gl, blkno, CREATE);
224 	if (!buffer_uptodate(*bhp))
225 		ll_rw_block(READ_META, 1, bhp);
226 	if (flags & DIO_WAIT) {
227 		int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
228 		if (error) {
229 			brelse(*bhp);
230 			return error;
231 		}
232 	}
233 
234 	return 0;
235 }
236 
237 /**
238  * gfs2_meta_wait - Reread a block from disk
239  * @sdp: the filesystem
240  * @bh: The block to wait for
241  *
242  * Returns: errno
243  */
244 
245 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
246 {
247 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
248 		return -EIO;
249 
250 	wait_on_buffer(bh);
251 
252 	if (!buffer_uptodate(bh)) {
253 		struct gfs2_trans *tr = current->journal_info;
254 		if (tr && tr->tr_touched)
255 			gfs2_io_error_bh(sdp, bh);
256 		return -EIO;
257 	}
258 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
259 		return -EIO;
260 
261 	return 0;
262 }
263 
264 /**
265  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
266  * @gl: the glock the buffer belongs to
267  * @bh: The buffer to be attached to
268  * @meta: Flag to indicate whether its metadata or not
269  */
270 
271 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
272 			 int meta)
273 {
274 	struct gfs2_bufdata *bd;
275 
276 	if (meta)
277 		lock_page(bh->b_page);
278 
279 	if (bh->b_private) {
280 		if (meta)
281 			unlock_page(bh->b_page);
282 		return;
283 	}
284 
285 	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
286 	bd->bd_bh = bh;
287 	bd->bd_gl = gl;
288 
289 	INIT_LIST_HEAD(&bd->bd_list_tr);
290 	if (meta)
291 		lops_init_le(&bd->bd_le, &gfs2_buf_lops);
292 	else
293 		lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
294 	bh->b_private = bd;
295 
296 	if (meta)
297 		unlock_page(bh->b_page);
298 }
299 
300 /**
301  * gfs2_pin - Pin a buffer in memory
302  * @sdp: the filesystem the buffer belongs to
303  * @bh: The buffer to be pinned
304  *
305  */
306 
307 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
308 {
309 	struct gfs2_bufdata *bd = bh->b_private;
310 
311 	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
312 
313 	if (test_set_buffer_pinned(bh))
314 		gfs2_assert_withdraw(sdp, 0);
315 
316 	wait_on_buffer(bh);
317 
318 	/* If this buffer is in the AIL and it has already been written
319 	   to in-place disk block, remove it from the AIL. */
320 
321 	gfs2_log_lock(sdp);
322 	if (bd->bd_ail && !buffer_in_io(bh))
323 		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
324 	gfs2_log_unlock(sdp);
325 
326 	clear_buffer_dirty(bh);
327 	wait_on_buffer(bh);
328 
329 	if (!buffer_uptodate(bh))
330 		gfs2_io_error_bh(sdp, bh);
331 
332 	get_bh(bh);
333 }
334 
335 /**
336  * gfs2_unpin - Unpin a buffer
337  * @sdp: the filesystem the buffer belongs to
338  * @bh: The buffer to unpin
339  * @ai:
340  *
341  */
342 
343 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
344 	        struct gfs2_ail *ai)
345 {
346 	struct gfs2_bufdata *bd = bh->b_private;
347 
348 	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
349 
350 	if (!buffer_pinned(bh))
351 		gfs2_assert_withdraw(sdp, 0);
352 
353 	mark_buffer_dirty(bh);
354 	clear_buffer_pinned(bh);
355 
356 	gfs2_log_lock(sdp);
357 	if (bd->bd_ail) {
358 		list_del(&bd->bd_ail_st_list);
359 		brelse(bh);
360 	} else {
361 		struct gfs2_glock *gl = bd->bd_gl;
362 		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
363 		atomic_inc(&gl->gl_ail_count);
364 	}
365 	bd->bd_ail = ai;
366 	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
367 	gfs2_log_unlock(sdp);
368 }
369 
370 /**
371  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
372  * @ip: the inode who owns the buffers
373  * @bstart: the first buffer in the run
374  * @blen: the number of buffers in the run
375  *
376  */
377 
378 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
379 {
380 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
381 	struct buffer_head *bh;
382 
383 	while (blen) {
384 		bh = getbuf(ip->i_gl, bstart, NO_CREATE);
385 		if (bh) {
386 			struct gfs2_bufdata *bd = bh->b_private;
387 
388 			if (test_clear_buffer_pinned(bh)) {
389 				struct gfs2_trans *tr = current->journal_info;
390 				gfs2_log_lock(sdp);
391 				list_del_init(&bd->bd_le.le_list);
392 				gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
393 				sdp->sd_log_num_buf--;
394 				gfs2_log_unlock(sdp);
395 				tr->tr_num_buf_rm++;
396 				brelse(bh);
397 			}
398 			if (bd) {
399 				gfs2_log_lock(sdp);
400 				if (bd->bd_ail) {
401 					u64 blkno = bh->b_blocknr;
402 					bd->bd_ail = NULL;
403 					list_del(&bd->bd_ail_st_list);
404 					list_del(&bd->bd_ail_gl_list);
405 					atomic_dec(&bd->bd_gl->gl_ail_count);
406 					brelse(bh);
407 					gfs2_log_unlock(sdp);
408 					gfs2_trans_add_revoke(sdp, blkno);
409 				} else
410 					gfs2_log_unlock(sdp);
411 			}
412 
413 			lock_buffer(bh);
414 			clear_buffer_dirty(bh);
415 			clear_buffer_uptodate(bh);
416 			unlock_buffer(bh);
417 
418 			brelse(bh);
419 		}
420 
421 		bstart++;
422 		blen--;
423 	}
424 }
425 
426 /**
427  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
428  * @ip: The GFS2 inode
429  *
430  * This releases buffers that are in the most-recently-used array of
431  * blocks used for indirect block addressing for this inode.
432  */
433 
434 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
435 {
436 	struct buffer_head **bh_slot;
437 	unsigned int x;
438 
439 	spin_lock(&ip->i_spin);
440 
441 	for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
442 		bh_slot = &ip->i_cache[x];
443 		if (!*bh_slot)
444 			break;
445 		brelse(*bh_slot);
446 		*bh_slot = NULL;
447 	}
448 
449 	spin_unlock(&ip->i_spin);
450 }
451 
452 /**
453  * gfs2_meta_indirect_buffer - Get a metadata buffer
454  * @ip: The GFS2 inode
455  * @height: The level of this buf in the metadata (indir addr) tree (if any)
456  * @num: The block number (device relative) of the buffer
457  * @new: Non-zero if we may create a new buffer
458  * @bhp: the buffer is returned here
459  *
460  * Try to use the gfs2_inode's MRU metadata tree cache.
461  *
462  * Returns: errno
463  */
464 
465 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
466 			      int new, struct buffer_head **bhp)
467 {
468 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
469 	struct gfs2_glock *gl = ip->i_gl;
470 	struct buffer_head *bh = NULL, **bh_slot = ip->i_cache + height;
471 	int in_cache = 0;
472 
473 	BUG_ON(!gl);
474 	BUG_ON(!sdp);
475 
476 	spin_lock(&ip->i_spin);
477 	if (*bh_slot && (*bh_slot)->b_blocknr == num) {
478 		bh = *bh_slot;
479 		get_bh(bh);
480 		in_cache = 1;
481 	}
482 	spin_unlock(&ip->i_spin);
483 
484 	if (!bh)
485 		bh = getbuf(gl, num, CREATE);
486 
487 	if (!bh)
488 		return -ENOBUFS;
489 
490 	if (new) {
491 		if (gfs2_assert_warn(sdp, height))
492 			goto err;
493 		meta_prep_new(bh);
494 		gfs2_trans_add_bh(ip->i_gl, bh, 1);
495 		gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
496 		gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
497 	} else {
498 		u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
499 		if (!buffer_uptodate(bh)) {
500 			ll_rw_block(READ_META, 1, &bh);
501 			if (gfs2_meta_wait(sdp, bh))
502 				goto err;
503 		}
504 		if (gfs2_metatype_check(sdp, bh, mtype))
505 			goto err;
506 	}
507 
508 	if (!in_cache) {
509 		spin_lock(&ip->i_spin);
510 		if (*bh_slot)
511 			brelse(*bh_slot);
512 		*bh_slot = bh;
513 		get_bh(bh);
514 		spin_unlock(&ip->i_spin);
515 	}
516 
517 	*bhp = bh;
518 	return 0;
519 err:
520 	brelse(bh);
521 	return -EIO;
522 }
523 
524 /**
525  * gfs2_meta_ra - start readahead on an extent of a file
526  * @gl: the glock the blocks belong to
527  * @dblock: the starting disk block
528  * @extlen: the number of blocks in the extent
529  *
530  * returns: the first buffer in the extent
531  */
532 
533 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
534 {
535 	struct gfs2_sbd *sdp = gl->gl_sbd;
536 	struct buffer_head *first_bh, *bh;
537 	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
538 			  sdp->sd_sb.sb_bsize_shift;
539 
540 	BUG_ON(!extlen);
541 
542 	if (max_ra < 1)
543 		max_ra = 1;
544 	if (extlen > max_ra)
545 		extlen = max_ra;
546 
547 	first_bh = getbuf(gl, dblock, CREATE);
548 
549 	if (buffer_uptodate(first_bh))
550 		goto out;
551 	if (!buffer_locked(first_bh))
552 		ll_rw_block(READ_META, 1, &first_bh);
553 
554 	dblock++;
555 	extlen--;
556 
557 	while (extlen) {
558 		bh = getbuf(gl, dblock, CREATE);
559 
560 		if (!buffer_uptodate(bh) && !buffer_locked(bh))
561 			ll_rw_block(READA, 1, &bh);
562 		brelse(bh);
563 		dblock++;
564 		extlen--;
565 		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
566 			goto out;
567 	}
568 
569 	wait_on_buffer(first_bh);
570 out:
571 	return first_bh;
572 }
573 
574