xref: /openbmc/linux/fs/nilfs2/segbuf.c (revision 679bd7eb)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * NILFS segment buffer
4  *
5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6  *
7  * Written by Ryusuke Konishi.
8  *
9  */
10 
11 #include <linux/buffer_head.h>
12 #include <linux/writeback.h>
13 #include <linux/crc32.h>
14 #include <linux/backing-dev.h>
15 #include <linux/slab.h>
16 #include "page.h"
17 #include "segbuf.h"
18 
19 
20 struct nilfs_write_info {
21 	struct the_nilfs       *nilfs;
22 	struct bio	       *bio;
23 	int			start, end; /* The region to be submitted */
24 	int			rest_blocks;
25 	int			max_pages;
26 	int			nr_vecs;
27 	sector_t		blocknr;
28 };
29 
30 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
31 			      struct the_nilfs *nilfs);
32 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
33 
nilfs_segbuf_new(struct super_block * sb)34 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
35 {
36 	struct nilfs_segment_buffer *segbuf;
37 
38 	segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);
39 	if (unlikely(!segbuf))
40 		return NULL;
41 
42 	segbuf->sb_super = sb;
43 	INIT_LIST_HEAD(&segbuf->sb_list);
44 	INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
45 	INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
46 	segbuf->sb_super_root = NULL;
47 
48 	init_completion(&segbuf->sb_bio_event);
49 	atomic_set(&segbuf->sb_err, 0);
50 	segbuf->sb_nbio = 0;
51 
52 	return segbuf;
53 }
54 
nilfs_segbuf_free(struct nilfs_segment_buffer * segbuf)55 void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
56 {
57 	kmem_cache_free(nilfs_segbuf_cachep, segbuf);
58 }
59 
nilfs_segbuf_map(struct nilfs_segment_buffer * segbuf,__u64 segnum,unsigned long offset,struct the_nilfs * nilfs)60 void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
61 		     unsigned long offset, struct the_nilfs *nilfs)
62 {
63 	segbuf->sb_segnum = segnum;
64 	nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
65 				&segbuf->sb_fseg_end);
66 
67 	segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;
68 	segbuf->sb_rest_blocks =
69 		segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
70 }
71 
72 /**
73  * nilfs_segbuf_map_cont - map a new log behind a given log
74  * @segbuf: new segment buffer
75  * @prev: segment buffer containing a log to be continued
76  */
nilfs_segbuf_map_cont(struct nilfs_segment_buffer * segbuf,struct nilfs_segment_buffer * prev)77 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
78 			   struct nilfs_segment_buffer *prev)
79 {
80 	segbuf->sb_segnum = prev->sb_segnum;
81 	segbuf->sb_fseg_start = prev->sb_fseg_start;
82 	segbuf->sb_fseg_end = prev->sb_fseg_end;
83 	segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;
84 	segbuf->sb_rest_blocks =
85 		segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
86 }
87 
nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer * segbuf,__u64 nextnum,struct the_nilfs * nilfs)88 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
89 				  __u64 nextnum, struct the_nilfs *nilfs)
90 {
91 	segbuf->sb_nextnum = nextnum;
92 	segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);
93 }
94 
nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer * segbuf)95 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
96 {
97 	struct buffer_head *bh;
98 
99 	bh = sb_getblk(segbuf->sb_super,
100 		       segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
101 	if (unlikely(!bh))
102 		return -ENOMEM;
103 
104 	lock_buffer(bh);
105 	if (!buffer_uptodate(bh)) {
106 		memset(bh->b_data, 0, bh->b_size);
107 		set_buffer_uptodate(bh);
108 	}
109 	unlock_buffer(bh);
110 	nilfs_segbuf_add_segsum_buffer(segbuf, bh);
111 	return 0;
112 }
113 
nilfs_segbuf_extend_payload(struct nilfs_segment_buffer * segbuf,struct buffer_head ** bhp)114 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
115 				struct buffer_head **bhp)
116 {
117 	struct buffer_head *bh;
118 
119 	bh = sb_getblk(segbuf->sb_super,
120 		       segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
121 	if (unlikely(!bh))
122 		return -ENOMEM;
123 
124 	nilfs_segbuf_add_payload_buffer(segbuf, bh);
125 	*bhp = bh;
126 	return 0;
127 }
128 
nilfs_segbuf_reset(struct nilfs_segment_buffer * segbuf,unsigned int flags,time64_t ctime,__u64 cno)129 int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned int flags,
130 		       time64_t ctime, __u64 cno)
131 {
132 	int err;
133 
134 	segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
135 	err = nilfs_segbuf_extend_segsum(segbuf);
136 	if (unlikely(err))
137 		return err;
138 
139 	segbuf->sb_sum.flags = flags;
140 	segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
141 	segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
142 	segbuf->sb_sum.ctime = ctime;
143 	segbuf->sb_sum.cno = cno;
144 	return 0;
145 }
146 
147 /*
148  * Setup segment summary
149  */
nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer * segbuf)150 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
151 {
152 	struct nilfs_segment_summary *raw_sum;
153 	struct buffer_head *bh_sum;
154 
155 	bh_sum = list_entry(segbuf->sb_segsum_buffers.next,
156 			    struct buffer_head, b_assoc_buffers);
157 	raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data;
158 
159 	raw_sum->ss_magic    = cpu_to_le32(NILFS_SEGSUM_MAGIC);
160 	raw_sum->ss_bytes    = cpu_to_le16(sizeof(*raw_sum));
161 	raw_sum->ss_flags    = cpu_to_le16(segbuf->sb_sum.flags);
162 	raw_sum->ss_seq      = cpu_to_le64(segbuf->sb_sum.seg_seq);
163 	raw_sum->ss_create   = cpu_to_le64(segbuf->sb_sum.ctime);
164 	raw_sum->ss_next     = cpu_to_le64(segbuf->sb_sum.next);
165 	raw_sum->ss_nblocks  = cpu_to_le32(segbuf->sb_sum.nblocks);
166 	raw_sum->ss_nfinfo   = cpu_to_le32(segbuf->sb_sum.nfinfo);
167 	raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes);
168 	raw_sum->ss_pad      = 0;
169 	raw_sum->ss_cno      = cpu_to_le64(segbuf->sb_sum.cno);
170 }
171 
172 /*
173  * CRC calculation routines
174  */
175 static void
nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer * segbuf,u32 seed)176 nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
177 {
178 	struct buffer_head *bh;
179 	struct nilfs_segment_summary *raw_sum;
180 	unsigned long size, bytes = segbuf->sb_sum.sumbytes;
181 	u32 crc;
182 
183 	bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
184 			b_assoc_buffers);
185 
186 	raw_sum = (struct nilfs_segment_summary *)bh->b_data;
187 	size = min_t(unsigned long, bytes, bh->b_size);
188 	crc = crc32_le(seed,
189 		       (unsigned char *)raw_sum +
190 		       sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
191 		       size - (sizeof(raw_sum->ss_datasum) +
192 			       sizeof(raw_sum->ss_sumsum)));
193 
194 	list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
195 				     b_assoc_buffers) {
196 		bytes -= size;
197 		size = min_t(unsigned long, bytes, bh->b_size);
198 		crc = crc32_le(crc, bh->b_data, size);
199 	}
200 	raw_sum->ss_sumsum = cpu_to_le32(crc);
201 }
202 
nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer * segbuf,u32 seed)203 static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
204 					  u32 seed)
205 {
206 	struct buffer_head *bh;
207 	struct nilfs_segment_summary *raw_sum;
208 	void *kaddr;
209 	u32 crc;
210 
211 	bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
212 			b_assoc_buffers);
213 	raw_sum = (struct nilfs_segment_summary *)bh->b_data;
214 	crc = crc32_le(seed,
215 		       (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
216 		       bh->b_size - sizeof(raw_sum->ss_datasum));
217 
218 	list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
219 				     b_assoc_buffers) {
220 		crc = crc32_le(crc, bh->b_data, bh->b_size);
221 	}
222 	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
223 		kaddr = kmap_atomic(bh->b_page);
224 		crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
225 		kunmap_atomic(kaddr);
226 	}
227 	raw_sum->ss_datasum = cpu_to_le32(crc);
228 }
229 
230 static void
nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer * segbuf,u32 seed)231 nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf,
232 				    u32 seed)
233 {
234 	struct nilfs_super_root *raw_sr;
235 	struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info;
236 	unsigned int srsize;
237 	u32 crc;
238 
239 	raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
240 	srsize = NILFS_SR_BYTES(nilfs->ns_inode_size);
241 	crc = crc32_le(seed,
242 		       (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
243 		       srsize - sizeof(raw_sr->sr_sum));
244 	raw_sr->sr_sum = cpu_to_le32(crc);
245 }
246 
nilfs_release_buffers(struct list_head * list)247 static void nilfs_release_buffers(struct list_head *list)
248 {
249 	struct buffer_head *bh, *n;
250 
251 	list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
252 		list_del_init(&bh->b_assoc_buffers);
253 		brelse(bh);
254 	}
255 }
256 
nilfs_segbuf_clear(struct nilfs_segment_buffer * segbuf)257 static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
258 {
259 	nilfs_release_buffers(&segbuf->sb_segsum_buffers);
260 	nilfs_release_buffers(&segbuf->sb_payload_buffers);
261 	segbuf->sb_super_root = NULL;
262 }
263 
264 /*
265  * Iterators for segment buffers
266  */
nilfs_clear_logs(struct list_head * logs)267 void nilfs_clear_logs(struct list_head *logs)
268 {
269 	struct nilfs_segment_buffer *segbuf;
270 
271 	list_for_each_entry(segbuf, logs, sb_list)
272 		nilfs_segbuf_clear(segbuf);
273 }
274 
nilfs_truncate_logs(struct list_head * logs,struct nilfs_segment_buffer * last)275 void nilfs_truncate_logs(struct list_head *logs,
276 			 struct nilfs_segment_buffer *last)
277 {
278 	struct nilfs_segment_buffer *n, *segbuf;
279 
280 	segbuf = list_prepare_entry(last, logs, sb_list);
281 	list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
282 		list_del_init(&segbuf->sb_list);
283 		nilfs_segbuf_clear(segbuf);
284 		nilfs_segbuf_free(segbuf);
285 	}
286 }
287 
nilfs_write_logs(struct list_head * logs,struct the_nilfs * nilfs)288 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
289 {
290 	struct nilfs_segment_buffer *segbuf;
291 	int ret = 0;
292 
293 	list_for_each_entry(segbuf, logs, sb_list) {
294 		ret = nilfs_segbuf_write(segbuf, nilfs);
295 		if (ret)
296 			break;
297 	}
298 	return ret;
299 }
300 
nilfs_wait_on_logs(struct list_head * logs)301 int nilfs_wait_on_logs(struct list_head *logs)
302 {
303 	struct nilfs_segment_buffer *segbuf;
304 	int err, ret = 0;
305 
306 	list_for_each_entry(segbuf, logs, sb_list) {
307 		err = nilfs_segbuf_wait(segbuf);
308 		if (err && !ret)
309 			ret = err;
310 	}
311 	return ret;
312 }
313 
314 /**
315  * nilfs_add_checksums_on_logs - add checksums on the logs
316  * @logs: list of segment buffers storing target logs
317  * @seed: checksum seed value
318  */
nilfs_add_checksums_on_logs(struct list_head * logs,u32 seed)319 void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
320 {
321 	struct nilfs_segment_buffer *segbuf;
322 
323 	list_for_each_entry(segbuf, logs, sb_list) {
324 		if (segbuf->sb_super_root)
325 			nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
326 		nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
327 		nilfs_segbuf_fill_in_data_crc(segbuf, seed);
328 	}
329 }
330 
331 /*
332  * BIO operations
333  */
nilfs_end_bio_write(struct bio * bio)334 static void nilfs_end_bio_write(struct bio *bio)
335 {
336 	struct nilfs_segment_buffer *segbuf = bio->bi_private;
337 
338 	if (bio->bi_status)
339 		atomic_inc(&segbuf->sb_err);
340 
341 	bio_put(bio);
342 	complete(&segbuf->sb_bio_event);
343 }
344 
nilfs_segbuf_submit_bio(struct nilfs_segment_buffer * segbuf,struct nilfs_write_info * wi)345 static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
346 				   struct nilfs_write_info *wi)
347 {
348 	struct bio *bio = wi->bio;
349 
350 	bio->bi_end_io = nilfs_end_bio_write;
351 	bio->bi_private = segbuf;
352 	submit_bio(bio);
353 	segbuf->sb_nbio++;
354 
355 	wi->bio = NULL;
356 	wi->rest_blocks -= wi->end - wi->start;
357 	wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
358 	wi->start = wi->end;
359 	return 0;
360 }
361 
nilfs_segbuf_prepare_write(struct nilfs_segment_buffer * segbuf,struct nilfs_write_info * wi)362 static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
363 				       struct nilfs_write_info *wi)
364 {
365 	wi->bio = NULL;
366 	wi->rest_blocks = segbuf->sb_sum.nblocks;
367 	wi->max_pages = BIO_MAX_VECS;
368 	wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
369 	wi->start = wi->end = 0;
370 	wi->blocknr = segbuf->sb_pseg_start;
371 }
372 
nilfs_segbuf_submit_bh(struct nilfs_segment_buffer * segbuf,struct nilfs_write_info * wi,struct buffer_head * bh)373 static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
374 				  struct nilfs_write_info *wi,
375 				  struct buffer_head *bh)
376 {
377 	int len, err;
378 
379 	BUG_ON(wi->nr_vecs <= 0);
380  repeat:
381 	if (!wi->bio) {
382 		wi->bio = bio_alloc(wi->nilfs->ns_bdev, wi->nr_vecs,
383 				    REQ_OP_WRITE, GFP_NOIO);
384 		wi->bio->bi_iter.bi_sector = (wi->blocknr + wi->end) <<
385 			(wi->nilfs->ns_blocksize_bits - 9);
386 	}
387 
388 	len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
389 	if (len == bh->b_size) {
390 		wi->end++;
391 		return 0;
392 	}
393 	/* bio is FULL */
394 	err = nilfs_segbuf_submit_bio(segbuf, wi);
395 	/* never submit current bh */
396 	if (likely(!err))
397 		goto repeat;
398 	return err;
399 }
400 
401 /**
402  * nilfs_segbuf_write - submit write requests of a log
403  * @segbuf: buffer storing a log to be written
404  * @nilfs: nilfs object
405  *
406  * Return Value: On Success, 0 is returned. On Error, one of the following
407  * negative error code is returned.
408  *
409  * %-EIO - I/O error
410  *
411  * %-ENOMEM - Insufficient memory available.
412  */
nilfs_segbuf_write(struct nilfs_segment_buffer * segbuf,struct the_nilfs * nilfs)413 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
414 			      struct the_nilfs *nilfs)
415 {
416 	struct nilfs_write_info wi;
417 	struct buffer_head *bh;
418 	int res = 0;
419 
420 	wi.nilfs = nilfs;
421 	nilfs_segbuf_prepare_write(segbuf, &wi);
422 
423 	list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
424 		res = nilfs_segbuf_submit_bh(segbuf, &wi, bh);
425 		if (unlikely(res))
426 			goto failed_bio;
427 	}
428 
429 	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
430 		res = nilfs_segbuf_submit_bh(segbuf, &wi, bh);
431 		if (unlikely(res))
432 			goto failed_bio;
433 	}
434 
435 	if (wi.bio) {
436 		/*
437 		 * Last BIO is always sent through the following
438 		 * submission.
439 		 */
440 		wi.bio->bi_opf |= REQ_SYNC;
441 		res = nilfs_segbuf_submit_bio(segbuf, &wi);
442 	}
443 
444  failed_bio:
445 	return res;
446 }
447 
448 /**
449  * nilfs_segbuf_wait - wait for completion of requested BIOs
450  * @segbuf: segment buffer
451  *
452  * Return Value: On Success, 0 is returned. On Error, one of the following
453  * negative error code is returned.
454  *
455  * %-EIO - I/O error
456  */
nilfs_segbuf_wait(struct nilfs_segment_buffer * segbuf)457 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
458 {
459 	int err = 0;
460 
461 	if (!segbuf->sb_nbio)
462 		return 0;
463 
464 	do {
465 		wait_for_completion(&segbuf->sb_bio_event);
466 	} while (--segbuf->sb_nbio > 0);
467 
468 	if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
469 		nilfs_err(segbuf->sb_super,
470 			  "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu",
471 			  (unsigned long long)segbuf->sb_pseg_start,
472 			  segbuf->sb_sum.nblocks,
473 			  (unsigned long long)segbuf->sb_segnum);
474 		err = -EIO;
475 	}
476 	return err;
477 }
478