xref: /openbmc/linux/fs/f2fs/compress.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * f2fs compress support
4  *
5  * Copyright (c) 2019 Chao Yu <chao@kernel.org>
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/f2fs_fs.h>
10 #include <linux/writeback.h>
11 #include <linux/backing-dev.h>
12 #include <linux/lzo.h>
13 #include <linux/lz4.h>
14 #include <linux/zstd.h>
15 
16 #include "f2fs.h"
17 #include "node.h"
18 #include <trace/events/f2fs.h>
19 
20 static struct kmem_cache *cic_entry_slab;
21 static struct kmem_cache *dic_entry_slab;
22 
23 static void *page_array_alloc(struct inode *inode, int nr)
24 {
25 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
26 	unsigned int size = sizeof(struct page *) * nr;
27 
28 	if (likely(size <= sbi->page_array_slab_size))
29 		return kmem_cache_zalloc(sbi->page_array_slab, GFP_NOFS);
30 	return f2fs_kzalloc(sbi, size, GFP_NOFS);
31 }
32 
33 static void page_array_free(struct inode *inode, void *pages, int nr)
34 {
35 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
36 	unsigned int size = sizeof(struct page *) * nr;
37 
38 	if (!pages)
39 		return;
40 
41 	if (likely(size <= sbi->page_array_slab_size))
42 		kmem_cache_free(sbi->page_array_slab, pages);
43 	else
44 		kfree(pages);
45 }
46 
47 struct f2fs_compress_ops {
48 	int (*init_compress_ctx)(struct compress_ctx *cc);
49 	void (*destroy_compress_ctx)(struct compress_ctx *cc);
50 	int (*compress_pages)(struct compress_ctx *cc);
51 	int (*init_decompress_ctx)(struct decompress_io_ctx *dic);
52 	void (*destroy_decompress_ctx)(struct decompress_io_ctx *dic);
53 	int (*decompress_pages)(struct decompress_io_ctx *dic);
54 };
55 
56 static unsigned int offset_in_cluster(struct compress_ctx *cc, pgoff_t index)
57 {
58 	return index & (cc->cluster_size - 1);
59 }
60 
61 static pgoff_t cluster_idx(struct compress_ctx *cc, pgoff_t index)
62 {
63 	return index >> cc->log_cluster_size;
64 }
65 
66 static pgoff_t start_idx_of_cluster(struct compress_ctx *cc)
67 {
68 	return cc->cluster_idx << cc->log_cluster_size;
69 }
70 
71 bool f2fs_is_compressed_page(struct page *page)
72 {
73 	if (!PagePrivate(page))
74 		return false;
75 	if (!page_private(page))
76 		return false;
77 	if (IS_ATOMIC_WRITTEN_PAGE(page) || IS_DUMMY_WRITTEN_PAGE(page))
78 		return false;
79 	/*
80 	 * page->private may be set with pid.
81 	 * pid_max is enough to check if it is traced.
82 	 */
83 	if (IS_IO_TRACED_PAGE(page))
84 		return false;
85 
86 	f2fs_bug_on(F2FS_M_SB(page->mapping),
87 		*((u32 *)page_private(page)) != F2FS_COMPRESSED_PAGE_MAGIC);
88 	return true;
89 }
90 
91 static void f2fs_set_compressed_page(struct page *page,
92 		struct inode *inode, pgoff_t index, void *data)
93 {
94 	SetPagePrivate(page);
95 	set_page_private(page, (unsigned long)data);
96 
97 	/* i_crypto_info and iv index */
98 	page->index = index;
99 	page->mapping = inode->i_mapping;
100 }
101 
102 static void f2fs_drop_rpages(struct compress_ctx *cc, int len, bool unlock)
103 {
104 	int i;
105 
106 	for (i = 0; i < len; i++) {
107 		if (!cc->rpages[i])
108 			continue;
109 		if (unlock)
110 			unlock_page(cc->rpages[i]);
111 		else
112 			put_page(cc->rpages[i]);
113 	}
114 }
115 
116 static void f2fs_put_rpages(struct compress_ctx *cc)
117 {
118 	f2fs_drop_rpages(cc, cc->cluster_size, false);
119 }
120 
121 static void f2fs_unlock_rpages(struct compress_ctx *cc, int len)
122 {
123 	f2fs_drop_rpages(cc, len, true);
124 }
125 
126 static void f2fs_put_rpages_mapping(struct address_space *mapping,
127 				pgoff_t start, int len)
128 {
129 	int i;
130 
131 	for (i = 0; i < len; i++) {
132 		struct page *page = find_get_page(mapping, start + i);
133 
134 		put_page(page);
135 		put_page(page);
136 	}
137 }
138 
139 static void f2fs_put_rpages_wbc(struct compress_ctx *cc,
140 		struct writeback_control *wbc, bool redirty, int unlock)
141 {
142 	unsigned int i;
143 
144 	for (i = 0; i < cc->cluster_size; i++) {
145 		if (!cc->rpages[i])
146 			continue;
147 		if (redirty)
148 			redirty_page_for_writepage(wbc, cc->rpages[i]);
149 		f2fs_put_page(cc->rpages[i], unlock);
150 	}
151 }
152 
153 struct page *f2fs_compress_control_page(struct page *page)
154 {
155 	return ((struct compress_io_ctx *)page_private(page))->rpages[0];
156 }
157 
158 int f2fs_init_compress_ctx(struct compress_ctx *cc)
159 {
160 	if (cc->rpages)
161 		return 0;
162 
163 	cc->rpages = page_array_alloc(cc->inode, cc->cluster_size);
164 	return cc->rpages ? 0 : -ENOMEM;
165 }
166 
167 void f2fs_destroy_compress_ctx(struct compress_ctx *cc)
168 {
169 	page_array_free(cc->inode, cc->rpages, cc->cluster_size);
170 	cc->rpages = NULL;
171 	cc->nr_rpages = 0;
172 	cc->nr_cpages = 0;
173 	cc->cluster_idx = NULL_CLUSTER;
174 }
175 
176 void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page)
177 {
178 	unsigned int cluster_ofs;
179 
180 	if (!f2fs_cluster_can_merge_page(cc, page->index))
181 		f2fs_bug_on(F2FS_I_SB(cc->inode), 1);
182 
183 	cluster_ofs = offset_in_cluster(cc, page->index);
184 	cc->rpages[cluster_ofs] = page;
185 	cc->nr_rpages++;
186 	cc->cluster_idx = cluster_idx(cc, page->index);
187 }
188 
189 #ifdef CONFIG_F2FS_FS_LZO
190 static int lzo_init_compress_ctx(struct compress_ctx *cc)
191 {
192 	cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
193 				LZO1X_MEM_COMPRESS, GFP_NOFS);
194 	if (!cc->private)
195 		return -ENOMEM;
196 
197 	cc->clen = lzo1x_worst_compress(PAGE_SIZE << cc->log_cluster_size);
198 	return 0;
199 }
200 
201 static void lzo_destroy_compress_ctx(struct compress_ctx *cc)
202 {
203 	kvfree(cc->private);
204 	cc->private = NULL;
205 }
206 
207 static int lzo_compress_pages(struct compress_ctx *cc)
208 {
209 	int ret;
210 
211 	ret = lzo1x_1_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
212 					&cc->clen, cc->private);
213 	if (ret != LZO_E_OK) {
214 		printk_ratelimited("%sF2FS-fs (%s): lzo compress failed, ret:%d\n",
215 				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, ret);
216 		return -EIO;
217 	}
218 	return 0;
219 }
220 
221 static int lzo_decompress_pages(struct decompress_io_ctx *dic)
222 {
223 	int ret;
224 
225 	ret = lzo1x_decompress_safe(dic->cbuf->cdata, dic->clen,
226 						dic->rbuf, &dic->rlen);
227 	if (ret != LZO_E_OK) {
228 		printk_ratelimited("%sF2FS-fs (%s): lzo decompress failed, ret:%d\n",
229 				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
230 		return -EIO;
231 	}
232 
233 	if (dic->rlen != PAGE_SIZE << dic->log_cluster_size) {
234 		printk_ratelimited("%sF2FS-fs (%s): lzo invalid rlen:%zu, "
235 					"expected:%lu\n", KERN_ERR,
236 					F2FS_I_SB(dic->inode)->sb->s_id,
237 					dic->rlen,
238 					PAGE_SIZE << dic->log_cluster_size);
239 		return -EIO;
240 	}
241 	return 0;
242 }
243 
244 static const struct f2fs_compress_ops f2fs_lzo_ops = {
245 	.init_compress_ctx	= lzo_init_compress_ctx,
246 	.destroy_compress_ctx	= lzo_destroy_compress_ctx,
247 	.compress_pages		= lzo_compress_pages,
248 	.decompress_pages	= lzo_decompress_pages,
249 };
250 #endif
251 
252 #ifdef CONFIG_F2FS_FS_LZ4
253 static int lz4_init_compress_ctx(struct compress_ctx *cc)
254 {
255 	unsigned int size = LZ4_MEM_COMPRESS;
256 
257 #ifdef CONFIG_F2FS_FS_LZ4HC
258 	if (F2FS_I(cc->inode)->i_compress_flag >> COMPRESS_LEVEL_OFFSET)
259 		size = LZ4HC_MEM_COMPRESS;
260 #endif
261 
262 	cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode), size, GFP_NOFS);
263 	if (!cc->private)
264 		return -ENOMEM;
265 
266 	/*
267 	 * we do not change cc->clen to LZ4_compressBound(inputsize) to
268 	 * adapt worst compress case, because lz4 compressor can handle
269 	 * output budget properly.
270 	 */
271 	cc->clen = cc->rlen - PAGE_SIZE - COMPRESS_HEADER_SIZE;
272 	return 0;
273 }
274 
275 static void lz4_destroy_compress_ctx(struct compress_ctx *cc)
276 {
277 	kvfree(cc->private);
278 	cc->private = NULL;
279 }
280 
281 #ifdef CONFIG_F2FS_FS_LZ4HC
282 static int lz4hc_compress_pages(struct compress_ctx *cc)
283 {
284 	unsigned char level = F2FS_I(cc->inode)->i_compress_flag >>
285 						COMPRESS_LEVEL_OFFSET;
286 	int len;
287 
288 	if (level)
289 		len = LZ4_compress_HC(cc->rbuf, cc->cbuf->cdata, cc->rlen,
290 					cc->clen, level, cc->private);
291 	else
292 		len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
293 						cc->clen, cc->private);
294 	if (!len)
295 		return -EAGAIN;
296 
297 	cc->clen = len;
298 	return 0;
299 }
300 #endif
301 
302 static int lz4_compress_pages(struct compress_ctx *cc)
303 {
304 	int len;
305 
306 #ifdef CONFIG_F2FS_FS_LZ4HC
307 	return lz4hc_compress_pages(cc);
308 #endif
309 	len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
310 						cc->clen, cc->private);
311 	if (!len)
312 		return -EAGAIN;
313 
314 	cc->clen = len;
315 	return 0;
316 }
317 
318 static int lz4_decompress_pages(struct decompress_io_ctx *dic)
319 {
320 	int ret;
321 
322 	ret = LZ4_decompress_safe(dic->cbuf->cdata, dic->rbuf,
323 						dic->clen, dic->rlen);
324 	if (ret < 0) {
325 		printk_ratelimited("%sF2FS-fs (%s): lz4 decompress failed, ret:%d\n",
326 				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
327 		return -EIO;
328 	}
329 
330 	if (ret != PAGE_SIZE << dic->log_cluster_size) {
331 		printk_ratelimited("%sF2FS-fs (%s): lz4 invalid rlen:%zu, "
332 					"expected:%lu\n", KERN_ERR,
333 					F2FS_I_SB(dic->inode)->sb->s_id,
334 					dic->rlen,
335 					PAGE_SIZE << dic->log_cluster_size);
336 		return -EIO;
337 	}
338 	return 0;
339 }
340 
341 static const struct f2fs_compress_ops f2fs_lz4_ops = {
342 	.init_compress_ctx	= lz4_init_compress_ctx,
343 	.destroy_compress_ctx	= lz4_destroy_compress_ctx,
344 	.compress_pages		= lz4_compress_pages,
345 	.decompress_pages	= lz4_decompress_pages,
346 };
347 #endif
348 
349 #ifdef CONFIG_F2FS_FS_ZSTD
350 #define F2FS_ZSTD_DEFAULT_CLEVEL	1
351 
352 static int zstd_init_compress_ctx(struct compress_ctx *cc)
353 {
354 	ZSTD_parameters params;
355 	ZSTD_CStream *stream;
356 	void *workspace;
357 	unsigned int workspace_size;
358 	unsigned char level = F2FS_I(cc->inode)->i_compress_flag >>
359 						COMPRESS_LEVEL_OFFSET;
360 
361 	if (!level)
362 		level = F2FS_ZSTD_DEFAULT_CLEVEL;
363 
364 	params = ZSTD_getParams(level, cc->rlen, 0);
365 	workspace_size = ZSTD_CStreamWorkspaceBound(params.cParams);
366 
367 	workspace = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
368 					workspace_size, GFP_NOFS);
369 	if (!workspace)
370 		return -ENOMEM;
371 
372 	stream = ZSTD_initCStream(params, 0, workspace, workspace_size);
373 	if (!stream) {
374 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_initCStream failed\n",
375 				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id,
376 				__func__);
377 		kvfree(workspace);
378 		return -EIO;
379 	}
380 
381 	cc->private = workspace;
382 	cc->private2 = stream;
383 
384 	cc->clen = cc->rlen - PAGE_SIZE - COMPRESS_HEADER_SIZE;
385 	return 0;
386 }
387 
388 static void zstd_destroy_compress_ctx(struct compress_ctx *cc)
389 {
390 	kvfree(cc->private);
391 	cc->private = NULL;
392 	cc->private2 = NULL;
393 }
394 
395 static int zstd_compress_pages(struct compress_ctx *cc)
396 {
397 	ZSTD_CStream *stream = cc->private2;
398 	ZSTD_inBuffer inbuf;
399 	ZSTD_outBuffer outbuf;
400 	int src_size = cc->rlen;
401 	int dst_size = src_size - PAGE_SIZE - COMPRESS_HEADER_SIZE;
402 	int ret;
403 
404 	inbuf.pos = 0;
405 	inbuf.src = cc->rbuf;
406 	inbuf.size = src_size;
407 
408 	outbuf.pos = 0;
409 	outbuf.dst = cc->cbuf->cdata;
410 	outbuf.size = dst_size;
411 
412 	ret = ZSTD_compressStream(stream, &outbuf, &inbuf);
413 	if (ZSTD_isError(ret)) {
414 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_compressStream failed, ret: %d\n",
415 				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id,
416 				__func__, ZSTD_getErrorCode(ret));
417 		return -EIO;
418 	}
419 
420 	ret = ZSTD_endStream(stream, &outbuf);
421 	if (ZSTD_isError(ret)) {
422 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_endStream returned %d\n",
423 				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id,
424 				__func__, ZSTD_getErrorCode(ret));
425 		return -EIO;
426 	}
427 
428 	/*
429 	 * there is compressed data remained in intermediate buffer due to
430 	 * no more space in cbuf.cdata
431 	 */
432 	if (ret)
433 		return -EAGAIN;
434 
435 	cc->clen = outbuf.pos;
436 	return 0;
437 }
438 
439 static int zstd_init_decompress_ctx(struct decompress_io_ctx *dic)
440 {
441 	ZSTD_DStream *stream;
442 	void *workspace;
443 	unsigned int workspace_size;
444 	unsigned int max_window_size =
445 			MAX_COMPRESS_WINDOW_SIZE(dic->log_cluster_size);
446 
447 	workspace_size = ZSTD_DStreamWorkspaceBound(max_window_size);
448 
449 	workspace = f2fs_kvmalloc(F2FS_I_SB(dic->inode),
450 					workspace_size, GFP_NOFS);
451 	if (!workspace)
452 		return -ENOMEM;
453 
454 	stream = ZSTD_initDStream(max_window_size, workspace, workspace_size);
455 	if (!stream) {
456 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_initDStream failed\n",
457 				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id,
458 				__func__);
459 		kvfree(workspace);
460 		return -EIO;
461 	}
462 
463 	dic->private = workspace;
464 	dic->private2 = stream;
465 
466 	return 0;
467 }
468 
469 static void zstd_destroy_decompress_ctx(struct decompress_io_ctx *dic)
470 {
471 	kvfree(dic->private);
472 	dic->private = NULL;
473 	dic->private2 = NULL;
474 }
475 
476 static int zstd_decompress_pages(struct decompress_io_ctx *dic)
477 {
478 	ZSTD_DStream *stream = dic->private2;
479 	ZSTD_inBuffer inbuf;
480 	ZSTD_outBuffer outbuf;
481 	int ret;
482 
483 	inbuf.pos = 0;
484 	inbuf.src = dic->cbuf->cdata;
485 	inbuf.size = dic->clen;
486 
487 	outbuf.pos = 0;
488 	outbuf.dst = dic->rbuf;
489 	outbuf.size = dic->rlen;
490 
491 	ret = ZSTD_decompressStream(stream, &outbuf, &inbuf);
492 	if (ZSTD_isError(ret)) {
493 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_compressStream failed, ret: %d\n",
494 				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id,
495 				__func__, ZSTD_getErrorCode(ret));
496 		return -EIO;
497 	}
498 
499 	if (dic->rlen != outbuf.pos) {
500 		printk_ratelimited("%sF2FS-fs (%s): %s ZSTD invalid rlen:%zu, "
501 				"expected:%lu\n", KERN_ERR,
502 				F2FS_I_SB(dic->inode)->sb->s_id,
503 				__func__, dic->rlen,
504 				PAGE_SIZE << dic->log_cluster_size);
505 		return -EIO;
506 	}
507 
508 	return 0;
509 }
510 
511 static const struct f2fs_compress_ops f2fs_zstd_ops = {
512 	.init_compress_ctx	= zstd_init_compress_ctx,
513 	.destroy_compress_ctx	= zstd_destroy_compress_ctx,
514 	.compress_pages		= zstd_compress_pages,
515 	.init_decompress_ctx	= zstd_init_decompress_ctx,
516 	.destroy_decompress_ctx	= zstd_destroy_decompress_ctx,
517 	.decompress_pages	= zstd_decompress_pages,
518 };
519 #endif
520 
521 #ifdef CONFIG_F2FS_FS_LZO
522 #ifdef CONFIG_F2FS_FS_LZORLE
523 static int lzorle_compress_pages(struct compress_ctx *cc)
524 {
525 	int ret;
526 
527 	ret = lzorle1x_1_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
528 					&cc->clen, cc->private);
529 	if (ret != LZO_E_OK) {
530 		printk_ratelimited("%sF2FS-fs (%s): lzo-rle compress failed, ret:%d\n",
531 				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, ret);
532 		return -EIO;
533 	}
534 	return 0;
535 }
536 
537 static const struct f2fs_compress_ops f2fs_lzorle_ops = {
538 	.init_compress_ctx	= lzo_init_compress_ctx,
539 	.destroy_compress_ctx	= lzo_destroy_compress_ctx,
540 	.compress_pages		= lzorle_compress_pages,
541 	.decompress_pages	= lzo_decompress_pages,
542 };
543 #endif
544 #endif
545 
546 static const struct f2fs_compress_ops *f2fs_cops[COMPRESS_MAX] = {
547 #ifdef CONFIG_F2FS_FS_LZO
548 	&f2fs_lzo_ops,
549 #else
550 	NULL,
551 #endif
552 #ifdef CONFIG_F2FS_FS_LZ4
553 	&f2fs_lz4_ops,
554 #else
555 	NULL,
556 #endif
557 #ifdef CONFIG_F2FS_FS_ZSTD
558 	&f2fs_zstd_ops,
559 #else
560 	NULL,
561 #endif
562 #if defined(CONFIG_F2FS_FS_LZO) && defined(CONFIG_F2FS_FS_LZORLE)
563 	&f2fs_lzorle_ops,
564 #else
565 	NULL,
566 #endif
567 };
568 
569 bool f2fs_is_compress_backend_ready(struct inode *inode)
570 {
571 	if (!f2fs_compressed_file(inode))
572 		return true;
573 	return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
574 }
575 
576 static mempool_t *compress_page_pool;
577 static int num_compress_pages = 512;
578 module_param(num_compress_pages, uint, 0444);
579 MODULE_PARM_DESC(num_compress_pages,
580 		"Number of intermediate compress pages to preallocate");
581 
582 int f2fs_init_compress_mempool(void)
583 {
584 	compress_page_pool = mempool_create_page_pool(num_compress_pages, 0);
585 	if (!compress_page_pool)
586 		return -ENOMEM;
587 
588 	return 0;
589 }
590 
591 void f2fs_destroy_compress_mempool(void)
592 {
593 	mempool_destroy(compress_page_pool);
594 }
595 
596 static struct page *f2fs_compress_alloc_page(void)
597 {
598 	struct page *page;
599 
600 	page = mempool_alloc(compress_page_pool, GFP_NOFS);
601 	lock_page(page);
602 
603 	return page;
604 }
605 
606 static void f2fs_compress_free_page(struct page *page)
607 {
608 	if (!page)
609 		return;
610 	set_page_private(page, (unsigned long)NULL);
611 	ClearPagePrivate(page);
612 	page->mapping = NULL;
613 	unlock_page(page);
614 	mempool_free(page, compress_page_pool);
615 }
616 
617 #define MAX_VMAP_RETRIES	3
618 
619 static void *f2fs_vmap(struct page **pages, unsigned int count)
620 {
621 	int i;
622 	void *buf = NULL;
623 
624 	for (i = 0; i < MAX_VMAP_RETRIES; i++) {
625 		buf = vm_map_ram(pages, count, -1);
626 		if (buf)
627 			break;
628 		vm_unmap_aliases();
629 	}
630 	return buf;
631 }
632 
633 static int f2fs_compress_pages(struct compress_ctx *cc)
634 {
635 	struct f2fs_inode_info *fi = F2FS_I(cc->inode);
636 	const struct f2fs_compress_ops *cops =
637 				f2fs_cops[fi->i_compress_algorithm];
638 	unsigned int max_len, new_nr_cpages;
639 	struct page **new_cpages;
640 	u32 chksum = 0;
641 	int i, ret;
642 
643 	trace_f2fs_compress_pages_start(cc->inode, cc->cluster_idx,
644 				cc->cluster_size, fi->i_compress_algorithm);
645 
646 	if (cops->init_compress_ctx) {
647 		ret = cops->init_compress_ctx(cc);
648 		if (ret)
649 			goto out;
650 	}
651 
652 	max_len = COMPRESS_HEADER_SIZE + cc->clen;
653 	cc->nr_cpages = DIV_ROUND_UP(max_len, PAGE_SIZE);
654 
655 	cc->cpages = page_array_alloc(cc->inode, cc->nr_cpages);
656 	if (!cc->cpages) {
657 		ret = -ENOMEM;
658 		goto destroy_compress_ctx;
659 	}
660 
661 	for (i = 0; i < cc->nr_cpages; i++) {
662 		cc->cpages[i] = f2fs_compress_alloc_page();
663 		if (!cc->cpages[i]) {
664 			ret = -ENOMEM;
665 			goto out_free_cpages;
666 		}
667 	}
668 
669 	cc->rbuf = f2fs_vmap(cc->rpages, cc->cluster_size);
670 	if (!cc->rbuf) {
671 		ret = -ENOMEM;
672 		goto out_free_cpages;
673 	}
674 
675 	cc->cbuf = f2fs_vmap(cc->cpages, cc->nr_cpages);
676 	if (!cc->cbuf) {
677 		ret = -ENOMEM;
678 		goto out_vunmap_rbuf;
679 	}
680 
681 	ret = cops->compress_pages(cc);
682 	if (ret)
683 		goto out_vunmap_cbuf;
684 
685 	max_len = PAGE_SIZE * (cc->cluster_size - 1) - COMPRESS_HEADER_SIZE;
686 
687 	if (cc->clen > max_len) {
688 		ret = -EAGAIN;
689 		goto out_vunmap_cbuf;
690 	}
691 
692 	cc->cbuf->clen = cpu_to_le32(cc->clen);
693 
694 	if (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)
695 		chksum = f2fs_crc32(F2FS_I_SB(cc->inode),
696 					cc->cbuf->cdata, cc->clen);
697 	cc->cbuf->chksum = cpu_to_le32(chksum);
698 
699 	for (i = 0; i < COMPRESS_DATA_RESERVED_SIZE; i++)
700 		cc->cbuf->reserved[i] = cpu_to_le32(0);
701 
702 	new_nr_cpages = DIV_ROUND_UP(cc->clen + COMPRESS_HEADER_SIZE, PAGE_SIZE);
703 
704 	/* Now we're going to cut unnecessary tail pages */
705 	new_cpages = page_array_alloc(cc->inode, new_nr_cpages);
706 	if (!new_cpages) {
707 		ret = -ENOMEM;
708 		goto out_vunmap_cbuf;
709 	}
710 
711 	/* zero out any unused part of the last page */
712 	memset(&cc->cbuf->cdata[cc->clen], 0,
713 			(new_nr_cpages * PAGE_SIZE) -
714 			(cc->clen + COMPRESS_HEADER_SIZE));
715 
716 	vm_unmap_ram(cc->cbuf, cc->nr_cpages);
717 	vm_unmap_ram(cc->rbuf, cc->cluster_size);
718 
719 	for (i = 0; i < cc->nr_cpages; i++) {
720 		if (i < new_nr_cpages) {
721 			new_cpages[i] = cc->cpages[i];
722 			continue;
723 		}
724 		f2fs_compress_free_page(cc->cpages[i]);
725 		cc->cpages[i] = NULL;
726 	}
727 
728 	if (cops->destroy_compress_ctx)
729 		cops->destroy_compress_ctx(cc);
730 
731 	page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
732 	cc->cpages = new_cpages;
733 	cc->nr_cpages = new_nr_cpages;
734 
735 	trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
736 							cc->clen, ret);
737 	return 0;
738 
739 out_vunmap_cbuf:
740 	vm_unmap_ram(cc->cbuf, cc->nr_cpages);
741 out_vunmap_rbuf:
742 	vm_unmap_ram(cc->rbuf, cc->cluster_size);
743 out_free_cpages:
744 	for (i = 0; i < cc->nr_cpages; i++) {
745 		if (cc->cpages[i])
746 			f2fs_compress_free_page(cc->cpages[i]);
747 	}
748 	page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
749 	cc->cpages = NULL;
750 destroy_compress_ctx:
751 	if (cops->destroy_compress_ctx)
752 		cops->destroy_compress_ctx(cc);
753 out:
754 	trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
755 							cc->clen, ret);
756 	return ret;
757 }
758 
759 static void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
760 {
761 	struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
762 	struct f2fs_inode_info *fi = F2FS_I(dic->inode);
763 	const struct f2fs_compress_ops *cops =
764 			f2fs_cops[fi->i_compress_algorithm];
765 	int ret;
766 	int i;
767 
768 	trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
769 				dic->cluster_size, fi->i_compress_algorithm);
770 
771 	if (dic->failed) {
772 		ret = -EIO;
773 		goto out_end_io;
774 	}
775 
776 	dic->tpages = page_array_alloc(dic->inode, dic->cluster_size);
777 	if (!dic->tpages) {
778 		ret = -ENOMEM;
779 		goto out_end_io;
780 	}
781 
782 	for (i = 0; i < dic->cluster_size; i++) {
783 		if (dic->rpages[i]) {
784 			dic->tpages[i] = dic->rpages[i];
785 			continue;
786 		}
787 
788 		dic->tpages[i] = f2fs_compress_alloc_page();
789 		if (!dic->tpages[i]) {
790 			ret = -ENOMEM;
791 			goto out_end_io;
792 		}
793 	}
794 
795 	if (cops->init_decompress_ctx) {
796 		ret = cops->init_decompress_ctx(dic);
797 		if (ret)
798 			goto out_end_io;
799 	}
800 
801 	dic->rbuf = f2fs_vmap(dic->tpages, dic->cluster_size);
802 	if (!dic->rbuf) {
803 		ret = -ENOMEM;
804 		goto out_destroy_decompress_ctx;
805 	}
806 
807 	dic->cbuf = f2fs_vmap(dic->cpages, dic->nr_cpages);
808 	if (!dic->cbuf) {
809 		ret = -ENOMEM;
810 		goto out_vunmap_rbuf;
811 	}
812 
813 	dic->clen = le32_to_cpu(dic->cbuf->clen);
814 	dic->rlen = PAGE_SIZE << dic->log_cluster_size;
815 
816 	if (dic->clen > PAGE_SIZE * dic->nr_cpages - COMPRESS_HEADER_SIZE) {
817 		ret = -EFSCORRUPTED;
818 		goto out_vunmap_cbuf;
819 	}
820 
821 	ret = cops->decompress_pages(dic);
822 
823 	if (!ret && (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)) {
824 		u32 provided = le32_to_cpu(dic->cbuf->chksum);
825 		u32 calculated = f2fs_crc32(sbi, dic->cbuf->cdata, dic->clen);
826 
827 		if (provided != calculated) {
828 			if (!is_inode_flag_set(dic->inode, FI_COMPRESS_CORRUPT)) {
829 				set_inode_flag(dic->inode, FI_COMPRESS_CORRUPT);
830 				printk_ratelimited(
831 					"%sF2FS-fs (%s): checksum invalid, nid = %lu, %x vs %x",
832 					KERN_INFO, sbi->sb->s_id, dic->inode->i_ino,
833 					provided, calculated);
834 			}
835 			set_sbi_flag(sbi, SBI_NEED_FSCK);
836 		}
837 	}
838 
839 out_vunmap_cbuf:
840 	vm_unmap_ram(dic->cbuf, dic->nr_cpages);
841 out_vunmap_rbuf:
842 	vm_unmap_ram(dic->rbuf, dic->cluster_size);
843 out_destroy_decompress_ctx:
844 	if (cops->destroy_decompress_ctx)
845 		cops->destroy_decompress_ctx(dic);
846 out_end_io:
847 	trace_f2fs_decompress_pages_end(dic->inode, dic->cluster_idx,
848 							dic->clen, ret);
849 	f2fs_decompress_end_io(dic, ret);
850 }
851 
852 /*
853  * This is called when a page of a compressed cluster has been read from disk
854  * (or failed to be read from disk).  It checks whether this page was the last
855  * page being waited on in the cluster, and if so, it decompresses the cluster
856  * (or in the case of a failure, cleans up without actually decompressing).
857  */
858 void f2fs_end_read_compressed_page(struct page *page, bool failed)
859 {
860 	struct decompress_io_ctx *dic =
861 			(struct decompress_io_ctx *)page_private(page);
862 	struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
863 
864 	dec_page_count(sbi, F2FS_RD_DATA);
865 
866 	if (failed)
867 		WRITE_ONCE(dic->failed, true);
868 
869 	if (atomic_dec_and_test(&dic->remaining_pages))
870 		f2fs_decompress_cluster(dic);
871 }
872 
873 static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
874 {
875 	if (cc->cluster_idx == NULL_CLUSTER)
876 		return true;
877 	return cc->cluster_idx == cluster_idx(cc, index);
878 }
879 
880 bool f2fs_cluster_is_empty(struct compress_ctx *cc)
881 {
882 	return cc->nr_rpages == 0;
883 }
884 
885 static bool f2fs_cluster_is_full(struct compress_ctx *cc)
886 {
887 	return cc->cluster_size == cc->nr_rpages;
888 }
889 
890 bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index)
891 {
892 	if (f2fs_cluster_is_empty(cc))
893 		return true;
894 	return is_page_in_cluster(cc, index);
895 }
896 
897 static bool __cluster_may_compress(struct compress_ctx *cc)
898 {
899 	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
900 	loff_t i_size = i_size_read(cc->inode);
901 	unsigned nr_pages = DIV_ROUND_UP(i_size, PAGE_SIZE);
902 	int i;
903 
904 	for (i = 0; i < cc->cluster_size; i++) {
905 		struct page *page = cc->rpages[i];
906 
907 		f2fs_bug_on(sbi, !page);
908 
909 		if (unlikely(f2fs_cp_error(sbi)))
910 			return false;
911 		if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
912 			return false;
913 
914 		/* beyond EOF */
915 		if (page->index >= nr_pages)
916 			return false;
917 	}
918 	return true;
919 }
920 
921 static int __f2fs_cluster_blocks(struct compress_ctx *cc, bool compr)
922 {
923 	struct dnode_of_data dn;
924 	int ret;
925 
926 	set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
927 	ret = f2fs_get_dnode_of_data(&dn, start_idx_of_cluster(cc),
928 							LOOKUP_NODE);
929 	if (ret) {
930 		if (ret == -ENOENT)
931 			ret = 0;
932 		goto fail;
933 	}
934 
935 	if (dn.data_blkaddr == COMPRESS_ADDR) {
936 		int i;
937 
938 		ret = 1;
939 		for (i = 1; i < cc->cluster_size; i++) {
940 			block_t blkaddr;
941 
942 			blkaddr = data_blkaddr(dn.inode,
943 					dn.node_page, dn.ofs_in_node + i);
944 			if (compr) {
945 				if (__is_valid_data_blkaddr(blkaddr))
946 					ret++;
947 			} else {
948 				if (blkaddr != NULL_ADDR)
949 					ret++;
950 			}
951 		}
952 	}
953 fail:
954 	f2fs_put_dnode(&dn);
955 	return ret;
956 }
957 
958 /* return # of compressed blocks in compressed cluster */
959 static int f2fs_compressed_blocks(struct compress_ctx *cc)
960 {
961 	return __f2fs_cluster_blocks(cc, true);
962 }
963 
964 /* return # of valid blocks in compressed cluster */
965 static int f2fs_cluster_blocks(struct compress_ctx *cc)
966 {
967 	return __f2fs_cluster_blocks(cc, false);
968 }
969 
970 int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index)
971 {
972 	struct compress_ctx cc = {
973 		.inode = inode,
974 		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
975 		.cluster_size = F2FS_I(inode)->i_cluster_size,
976 		.cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
977 	};
978 
979 	return f2fs_cluster_blocks(&cc);
980 }
981 
982 static bool cluster_may_compress(struct compress_ctx *cc)
983 {
984 	if (!f2fs_need_compress_data(cc->inode))
985 		return false;
986 	if (f2fs_is_atomic_file(cc->inode))
987 		return false;
988 	if (f2fs_is_mmap_file(cc->inode))
989 		return false;
990 	if (!f2fs_cluster_is_full(cc))
991 		return false;
992 	if (unlikely(f2fs_cp_error(F2FS_I_SB(cc->inode))))
993 		return false;
994 	return __cluster_may_compress(cc);
995 }
996 
997 static void set_cluster_writeback(struct compress_ctx *cc)
998 {
999 	int i;
1000 
1001 	for (i = 0; i < cc->cluster_size; i++) {
1002 		if (cc->rpages[i])
1003 			set_page_writeback(cc->rpages[i]);
1004 	}
1005 }
1006 
1007 static void set_cluster_dirty(struct compress_ctx *cc)
1008 {
1009 	int i;
1010 
1011 	for (i = 0; i < cc->cluster_size; i++)
1012 		if (cc->rpages[i])
1013 			set_page_dirty(cc->rpages[i]);
1014 }
1015 
1016 static int prepare_compress_overwrite(struct compress_ctx *cc,
1017 		struct page **pagep, pgoff_t index, void **fsdata)
1018 {
1019 	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
1020 	struct address_space *mapping = cc->inode->i_mapping;
1021 	struct page *page;
1022 	struct dnode_of_data dn;
1023 	sector_t last_block_in_bio;
1024 	unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
1025 	pgoff_t start_idx = start_idx_of_cluster(cc);
1026 	int i, ret;
1027 	bool prealloc;
1028 
1029 retry:
1030 	ret = f2fs_cluster_blocks(cc);
1031 	if (ret <= 0)
1032 		return ret;
1033 
1034 	/* compressed case */
1035 	prealloc = (ret < cc->cluster_size);
1036 
1037 	ret = f2fs_init_compress_ctx(cc);
1038 	if (ret)
1039 		return ret;
1040 
1041 	/* keep page reference to avoid page reclaim */
1042 	for (i = 0; i < cc->cluster_size; i++) {
1043 		page = f2fs_pagecache_get_page(mapping, start_idx + i,
1044 							fgp_flag, GFP_NOFS);
1045 		if (!page) {
1046 			ret = -ENOMEM;
1047 			goto unlock_pages;
1048 		}
1049 
1050 		if (PageUptodate(page))
1051 			unlock_page(page);
1052 		else
1053 			f2fs_compress_ctx_add_page(cc, page);
1054 	}
1055 
1056 	if (!f2fs_cluster_is_empty(cc)) {
1057 		struct bio *bio = NULL;
1058 
1059 		ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
1060 					&last_block_in_bio, false, true);
1061 		f2fs_destroy_compress_ctx(cc);
1062 		if (ret)
1063 			goto release_pages;
1064 		if (bio)
1065 			f2fs_submit_bio(sbi, bio, DATA);
1066 
1067 		ret = f2fs_init_compress_ctx(cc);
1068 		if (ret)
1069 			goto release_pages;
1070 	}
1071 
1072 	for (i = 0; i < cc->cluster_size; i++) {
1073 		f2fs_bug_on(sbi, cc->rpages[i]);
1074 
1075 		page = find_lock_page(mapping, start_idx + i);
1076 		f2fs_bug_on(sbi, !page);
1077 
1078 		f2fs_wait_on_page_writeback(page, DATA, true, true);
1079 
1080 		f2fs_compress_ctx_add_page(cc, page);
1081 		f2fs_put_page(page, 0);
1082 
1083 		if (!PageUptodate(page)) {
1084 			f2fs_unlock_rpages(cc, i + 1);
1085 			f2fs_put_rpages_mapping(mapping, start_idx,
1086 					cc->cluster_size);
1087 			f2fs_destroy_compress_ctx(cc);
1088 			goto retry;
1089 		}
1090 	}
1091 
1092 	if (prealloc) {
1093 		f2fs_do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
1094 
1095 		set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
1096 
1097 		for (i = cc->cluster_size - 1; i > 0; i--) {
1098 			ret = f2fs_get_block(&dn, start_idx + i);
1099 			if (ret) {
1100 				i = cc->cluster_size;
1101 				break;
1102 			}
1103 
1104 			if (dn.data_blkaddr != NEW_ADDR)
1105 				break;
1106 		}
1107 
1108 		f2fs_do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
1109 	}
1110 
1111 	if (likely(!ret)) {
1112 		*fsdata = cc->rpages;
1113 		*pagep = cc->rpages[offset_in_cluster(cc, index)];
1114 		return cc->cluster_size;
1115 	}
1116 
1117 unlock_pages:
1118 	f2fs_unlock_rpages(cc, i);
1119 release_pages:
1120 	f2fs_put_rpages_mapping(mapping, start_idx, i);
1121 	f2fs_destroy_compress_ctx(cc);
1122 	return ret;
1123 }
1124 
1125 int f2fs_prepare_compress_overwrite(struct inode *inode,
1126 		struct page **pagep, pgoff_t index, void **fsdata)
1127 {
1128 	struct compress_ctx cc = {
1129 		.inode = inode,
1130 		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
1131 		.cluster_size = F2FS_I(inode)->i_cluster_size,
1132 		.cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
1133 		.rpages = NULL,
1134 		.nr_rpages = 0,
1135 	};
1136 
1137 	return prepare_compress_overwrite(&cc, pagep, index, fsdata);
1138 }
1139 
1140 bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
1141 					pgoff_t index, unsigned copied)
1142 
1143 {
1144 	struct compress_ctx cc = {
1145 		.inode = inode,
1146 		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
1147 		.cluster_size = F2FS_I(inode)->i_cluster_size,
1148 		.rpages = fsdata,
1149 	};
1150 	bool first_index = (index == cc.rpages[0]->index);
1151 
1152 	if (copied)
1153 		set_cluster_dirty(&cc);
1154 
1155 	f2fs_put_rpages_wbc(&cc, NULL, false, 1);
1156 	f2fs_destroy_compress_ctx(&cc);
1157 
1158 	return first_index;
1159 }
1160 
1161 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock)
1162 {
1163 	void *fsdata = NULL;
1164 	struct page *pagep;
1165 	int log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
1166 	pgoff_t start_idx = from >> (PAGE_SHIFT + log_cluster_size) <<
1167 							log_cluster_size;
1168 	int err;
1169 
1170 	err = f2fs_is_compressed_cluster(inode, start_idx);
1171 	if (err < 0)
1172 		return err;
1173 
1174 	/* truncate normal cluster */
1175 	if (!err)
1176 		return f2fs_do_truncate_blocks(inode, from, lock);
1177 
1178 	/* truncate compressed cluster */
1179 	err = f2fs_prepare_compress_overwrite(inode, &pagep,
1180 						start_idx, &fsdata);
1181 
1182 	/* should not be a normal cluster */
1183 	f2fs_bug_on(F2FS_I_SB(inode), err == 0);
1184 
1185 	if (err <= 0)
1186 		return err;
1187 
1188 	if (err > 0) {
1189 		struct page **rpages = fsdata;
1190 		int cluster_size = F2FS_I(inode)->i_cluster_size;
1191 		int i;
1192 
1193 		for (i = cluster_size - 1; i >= 0; i--) {
1194 			loff_t start = rpages[i]->index << PAGE_SHIFT;
1195 
1196 			if (from <= start) {
1197 				zero_user_segment(rpages[i], 0, PAGE_SIZE);
1198 			} else {
1199 				zero_user_segment(rpages[i], from - start,
1200 								PAGE_SIZE);
1201 				break;
1202 			}
1203 		}
1204 
1205 		f2fs_compress_write_end(inode, fsdata, start_idx, true);
1206 	}
1207 	return 0;
1208 }
1209 
1210 static int f2fs_write_compressed_pages(struct compress_ctx *cc,
1211 					int *submitted,
1212 					struct writeback_control *wbc,
1213 					enum iostat_type io_type)
1214 {
1215 	struct inode *inode = cc->inode;
1216 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1217 	struct f2fs_inode_info *fi = F2FS_I(inode);
1218 	struct f2fs_io_info fio = {
1219 		.sbi = sbi,
1220 		.ino = cc->inode->i_ino,
1221 		.type = DATA,
1222 		.op = REQ_OP_WRITE,
1223 		.op_flags = wbc_to_write_flags(wbc),
1224 		.old_blkaddr = NEW_ADDR,
1225 		.page = NULL,
1226 		.encrypted_page = NULL,
1227 		.compressed_page = NULL,
1228 		.submitted = false,
1229 		.io_type = io_type,
1230 		.io_wbc = wbc,
1231 		.encrypted = fscrypt_inode_uses_fs_layer_crypto(cc->inode),
1232 	};
1233 	struct dnode_of_data dn;
1234 	struct node_info ni;
1235 	struct compress_io_ctx *cic;
1236 	pgoff_t start_idx = start_idx_of_cluster(cc);
1237 	unsigned int last_index = cc->cluster_size - 1;
1238 	loff_t psize;
1239 	int i, err;
1240 
1241 	if (IS_NOQUOTA(inode)) {
1242 		/*
1243 		 * We need to wait for node_write to avoid block allocation during
1244 		 * checkpoint. This can only happen to quota writes which can cause
1245 		 * the below discard race condition.
1246 		 */
1247 		down_read(&sbi->node_write);
1248 	} else if (!f2fs_trylock_op(sbi)) {
1249 		goto out_free;
1250 	}
1251 
1252 	set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
1253 
1254 	err = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
1255 	if (err)
1256 		goto out_unlock_op;
1257 
1258 	for (i = 0; i < cc->cluster_size; i++) {
1259 		if (data_blkaddr(dn.inode, dn.node_page,
1260 					dn.ofs_in_node + i) == NULL_ADDR)
1261 			goto out_put_dnode;
1262 	}
1263 
1264 	psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
1265 
1266 	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
1267 	if (err)
1268 		goto out_put_dnode;
1269 
1270 	fio.version = ni.version;
1271 
1272 	cic = kmem_cache_zalloc(cic_entry_slab, GFP_NOFS);
1273 	if (!cic)
1274 		goto out_put_dnode;
1275 
1276 	cic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
1277 	cic->inode = inode;
1278 	atomic_set(&cic->pending_pages, cc->nr_cpages);
1279 	cic->rpages = page_array_alloc(cc->inode, cc->cluster_size);
1280 	if (!cic->rpages)
1281 		goto out_put_cic;
1282 
1283 	cic->nr_rpages = cc->cluster_size;
1284 
1285 	for (i = 0; i < cc->nr_cpages; i++) {
1286 		f2fs_set_compressed_page(cc->cpages[i], inode,
1287 					cc->rpages[i + 1]->index, cic);
1288 		fio.compressed_page = cc->cpages[i];
1289 
1290 		fio.old_blkaddr = data_blkaddr(dn.inode, dn.node_page,
1291 						dn.ofs_in_node + i + 1);
1292 
1293 		/* wait for GCed page writeback via META_MAPPING */
1294 		f2fs_wait_on_block_writeback(inode, fio.old_blkaddr);
1295 
1296 		if (fio.encrypted) {
1297 			fio.page = cc->rpages[i + 1];
1298 			err = f2fs_encrypt_one_page(&fio);
1299 			if (err)
1300 				goto out_destroy_crypt;
1301 			cc->cpages[i] = fio.encrypted_page;
1302 		}
1303 	}
1304 
1305 	set_cluster_writeback(cc);
1306 
1307 	for (i = 0; i < cc->cluster_size; i++)
1308 		cic->rpages[i] = cc->rpages[i];
1309 
1310 	for (i = 0; i < cc->cluster_size; i++, dn.ofs_in_node++) {
1311 		block_t blkaddr;
1312 
1313 		blkaddr = f2fs_data_blkaddr(&dn);
1314 		fio.page = cc->rpages[i];
1315 		fio.old_blkaddr = blkaddr;
1316 
1317 		/* cluster header */
1318 		if (i == 0) {
1319 			if (blkaddr == COMPRESS_ADDR)
1320 				fio.compr_blocks++;
1321 			if (__is_valid_data_blkaddr(blkaddr))
1322 				f2fs_invalidate_blocks(sbi, blkaddr);
1323 			f2fs_update_data_blkaddr(&dn, COMPRESS_ADDR);
1324 			goto unlock_continue;
1325 		}
1326 
1327 		if (fio.compr_blocks && __is_valid_data_blkaddr(blkaddr))
1328 			fio.compr_blocks++;
1329 
1330 		if (i > cc->nr_cpages) {
1331 			if (__is_valid_data_blkaddr(blkaddr)) {
1332 				f2fs_invalidate_blocks(sbi, blkaddr);
1333 				f2fs_update_data_blkaddr(&dn, NEW_ADDR);
1334 			}
1335 			goto unlock_continue;
1336 		}
1337 
1338 		f2fs_bug_on(fio.sbi, blkaddr == NULL_ADDR);
1339 
1340 		if (fio.encrypted)
1341 			fio.encrypted_page = cc->cpages[i - 1];
1342 		else
1343 			fio.compressed_page = cc->cpages[i - 1];
1344 
1345 		cc->cpages[i - 1] = NULL;
1346 		f2fs_outplace_write_data(&dn, &fio);
1347 		(*submitted)++;
1348 unlock_continue:
1349 		inode_dec_dirty_pages(cc->inode);
1350 		unlock_page(fio.page);
1351 	}
1352 
1353 	if (fio.compr_blocks)
1354 		f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
1355 	f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
1356 
1357 	set_inode_flag(cc->inode, FI_APPEND_WRITE);
1358 	if (cc->cluster_idx == 0)
1359 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1360 
1361 	f2fs_put_dnode(&dn);
1362 	if (IS_NOQUOTA(inode))
1363 		up_read(&sbi->node_write);
1364 	else
1365 		f2fs_unlock_op(sbi);
1366 
1367 	spin_lock(&fi->i_size_lock);
1368 	if (fi->last_disk_size < psize)
1369 		fi->last_disk_size = psize;
1370 	spin_unlock(&fi->i_size_lock);
1371 
1372 	f2fs_put_rpages(cc);
1373 	page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
1374 	cc->cpages = NULL;
1375 	f2fs_destroy_compress_ctx(cc);
1376 	return 0;
1377 
1378 out_destroy_crypt:
1379 	page_array_free(cc->inode, cic->rpages, cc->cluster_size);
1380 
1381 	for (--i; i >= 0; i--)
1382 		fscrypt_finalize_bounce_page(&cc->cpages[i]);
1383 	for (i = 0; i < cc->nr_cpages; i++) {
1384 		if (!cc->cpages[i])
1385 			continue;
1386 		f2fs_put_page(cc->cpages[i], 1);
1387 	}
1388 out_put_cic:
1389 	kmem_cache_free(cic_entry_slab, cic);
1390 out_put_dnode:
1391 	f2fs_put_dnode(&dn);
1392 out_unlock_op:
1393 	if (IS_NOQUOTA(inode))
1394 		up_read(&sbi->node_write);
1395 	else
1396 		f2fs_unlock_op(sbi);
1397 out_free:
1398 	page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
1399 	cc->cpages = NULL;
1400 	return -EAGAIN;
1401 }
1402 
1403 void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
1404 {
1405 	struct f2fs_sb_info *sbi = bio->bi_private;
1406 	struct compress_io_ctx *cic =
1407 			(struct compress_io_ctx *)page_private(page);
1408 	int i;
1409 
1410 	if (unlikely(bio->bi_status))
1411 		mapping_set_error(cic->inode->i_mapping, -EIO);
1412 
1413 	f2fs_compress_free_page(page);
1414 
1415 	dec_page_count(sbi, F2FS_WB_DATA);
1416 
1417 	if (atomic_dec_return(&cic->pending_pages))
1418 		return;
1419 
1420 	for (i = 0; i < cic->nr_rpages; i++) {
1421 		WARN_ON(!cic->rpages[i]);
1422 		clear_cold_data(cic->rpages[i]);
1423 		end_page_writeback(cic->rpages[i]);
1424 	}
1425 
1426 	page_array_free(cic->inode, cic->rpages, cic->nr_rpages);
1427 	kmem_cache_free(cic_entry_slab, cic);
1428 }
1429 
1430 static int f2fs_write_raw_pages(struct compress_ctx *cc,
1431 					int *submitted,
1432 					struct writeback_control *wbc,
1433 					enum iostat_type io_type)
1434 {
1435 	struct address_space *mapping = cc->inode->i_mapping;
1436 	int _submitted, compr_blocks, ret;
1437 	int i = -1, err = 0;
1438 
1439 	compr_blocks = f2fs_compressed_blocks(cc);
1440 	if (compr_blocks < 0) {
1441 		err = compr_blocks;
1442 		goto out_err;
1443 	}
1444 
1445 	for (i = 0; i < cc->cluster_size; i++) {
1446 		if (!cc->rpages[i])
1447 			continue;
1448 retry_write:
1449 		if (cc->rpages[i]->mapping != mapping) {
1450 			unlock_page(cc->rpages[i]);
1451 			continue;
1452 		}
1453 
1454 		BUG_ON(!PageLocked(cc->rpages[i]));
1455 
1456 		ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted,
1457 						NULL, NULL, wbc, io_type,
1458 						compr_blocks, false);
1459 		if (ret) {
1460 			if (ret == AOP_WRITEPAGE_ACTIVATE) {
1461 				unlock_page(cc->rpages[i]);
1462 				ret = 0;
1463 			} else if (ret == -EAGAIN) {
1464 				/*
1465 				 * for quota file, just redirty left pages to
1466 				 * avoid deadlock caused by cluster update race
1467 				 * from foreground operation.
1468 				 */
1469 				if (IS_NOQUOTA(cc->inode)) {
1470 					err = 0;
1471 					goto out_err;
1472 				}
1473 				ret = 0;
1474 				cond_resched();
1475 				congestion_wait(BLK_RW_ASYNC,
1476 						DEFAULT_IO_TIMEOUT);
1477 				lock_page(cc->rpages[i]);
1478 
1479 				if (!PageDirty(cc->rpages[i])) {
1480 					unlock_page(cc->rpages[i]);
1481 					continue;
1482 				}
1483 
1484 				clear_page_dirty_for_io(cc->rpages[i]);
1485 				goto retry_write;
1486 			}
1487 			err = ret;
1488 			goto out_err;
1489 		}
1490 
1491 		*submitted += _submitted;
1492 	}
1493 
1494 	f2fs_balance_fs(F2FS_M_SB(mapping), true);
1495 
1496 	return 0;
1497 out_err:
1498 	for (++i; i < cc->cluster_size; i++) {
1499 		if (!cc->rpages[i])
1500 			continue;
1501 		redirty_page_for_writepage(wbc, cc->rpages[i]);
1502 		unlock_page(cc->rpages[i]);
1503 	}
1504 	return err;
1505 }
1506 
1507 int f2fs_write_multi_pages(struct compress_ctx *cc,
1508 					int *submitted,
1509 					struct writeback_control *wbc,
1510 					enum iostat_type io_type)
1511 {
1512 	int err;
1513 
1514 	*submitted = 0;
1515 	if (cluster_may_compress(cc)) {
1516 		err = f2fs_compress_pages(cc);
1517 		if (err == -EAGAIN) {
1518 			goto write;
1519 		} else if (err) {
1520 			f2fs_put_rpages_wbc(cc, wbc, true, 1);
1521 			goto destroy_out;
1522 		}
1523 
1524 		err = f2fs_write_compressed_pages(cc, submitted,
1525 							wbc, io_type);
1526 		if (!err)
1527 			return 0;
1528 		f2fs_bug_on(F2FS_I_SB(cc->inode), err != -EAGAIN);
1529 	}
1530 write:
1531 	f2fs_bug_on(F2FS_I_SB(cc->inode), *submitted);
1532 
1533 	err = f2fs_write_raw_pages(cc, submitted, wbc, io_type);
1534 	f2fs_put_rpages_wbc(cc, wbc, false, 0);
1535 destroy_out:
1536 	f2fs_destroy_compress_ctx(cc);
1537 	return err;
1538 }
1539 
1540 static void f2fs_free_dic(struct decompress_io_ctx *dic);
1541 
1542 struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
1543 {
1544 	struct decompress_io_ctx *dic;
1545 	pgoff_t start_idx = start_idx_of_cluster(cc);
1546 	int i;
1547 
1548 	dic = kmem_cache_zalloc(dic_entry_slab, GFP_NOFS);
1549 	if (!dic)
1550 		return ERR_PTR(-ENOMEM);
1551 
1552 	dic->rpages = page_array_alloc(cc->inode, cc->cluster_size);
1553 	if (!dic->rpages) {
1554 		kmem_cache_free(dic_entry_slab, dic);
1555 		return ERR_PTR(-ENOMEM);
1556 	}
1557 
1558 	dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
1559 	dic->inode = cc->inode;
1560 	atomic_set(&dic->remaining_pages, cc->nr_cpages);
1561 	dic->cluster_idx = cc->cluster_idx;
1562 	dic->cluster_size = cc->cluster_size;
1563 	dic->log_cluster_size = cc->log_cluster_size;
1564 	dic->nr_cpages = cc->nr_cpages;
1565 	refcount_set(&dic->refcnt, 1);
1566 	dic->failed = false;
1567 	dic->need_verity = f2fs_need_verity(cc->inode, start_idx);
1568 
1569 	for (i = 0; i < dic->cluster_size; i++)
1570 		dic->rpages[i] = cc->rpages[i];
1571 	dic->nr_rpages = cc->cluster_size;
1572 
1573 	dic->cpages = page_array_alloc(dic->inode, dic->nr_cpages);
1574 	if (!dic->cpages)
1575 		goto out_free;
1576 
1577 	for (i = 0; i < dic->nr_cpages; i++) {
1578 		struct page *page;
1579 
1580 		page = f2fs_compress_alloc_page();
1581 		if (!page)
1582 			goto out_free;
1583 
1584 		f2fs_set_compressed_page(page, cc->inode,
1585 					start_idx + i + 1, dic);
1586 		dic->cpages[i] = page;
1587 	}
1588 
1589 	return dic;
1590 
1591 out_free:
1592 	f2fs_free_dic(dic);
1593 	return ERR_PTR(-ENOMEM);
1594 }
1595 
1596 static void f2fs_free_dic(struct decompress_io_ctx *dic)
1597 {
1598 	int i;
1599 
1600 	if (dic->tpages) {
1601 		for (i = 0; i < dic->cluster_size; i++) {
1602 			if (dic->rpages[i])
1603 				continue;
1604 			if (!dic->tpages[i])
1605 				continue;
1606 			f2fs_compress_free_page(dic->tpages[i]);
1607 		}
1608 		page_array_free(dic->inode, dic->tpages, dic->cluster_size);
1609 	}
1610 
1611 	if (dic->cpages) {
1612 		for (i = 0; i < dic->nr_cpages; i++) {
1613 			if (!dic->cpages[i])
1614 				continue;
1615 			f2fs_compress_free_page(dic->cpages[i]);
1616 		}
1617 		page_array_free(dic->inode, dic->cpages, dic->nr_cpages);
1618 	}
1619 
1620 	page_array_free(dic->inode, dic->rpages, dic->nr_rpages);
1621 	kmem_cache_free(dic_entry_slab, dic);
1622 }
1623 
1624 static void f2fs_put_dic(struct decompress_io_ctx *dic)
1625 {
1626 	if (refcount_dec_and_test(&dic->refcnt))
1627 		f2fs_free_dic(dic);
1628 }
1629 
1630 /*
1631  * Update and unlock the cluster's pagecache pages, and release the reference to
1632  * the decompress_io_ctx that was being held for I/O completion.
1633  */
1634 static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
1635 {
1636 	int i;
1637 
1638 	for (i = 0; i < dic->cluster_size; i++) {
1639 		struct page *rpage = dic->rpages[i];
1640 
1641 		if (!rpage)
1642 			continue;
1643 
1644 		/* PG_error was set if verity failed. */
1645 		if (failed || PageError(rpage)) {
1646 			ClearPageUptodate(rpage);
1647 			/* will re-read again later */
1648 			ClearPageError(rpage);
1649 		} else {
1650 			SetPageUptodate(rpage);
1651 		}
1652 		unlock_page(rpage);
1653 	}
1654 
1655 	f2fs_put_dic(dic);
1656 }
1657 
1658 static void f2fs_verify_cluster(struct work_struct *work)
1659 {
1660 	struct decompress_io_ctx *dic =
1661 		container_of(work, struct decompress_io_ctx, verity_work);
1662 	int i;
1663 
1664 	/* Verify the cluster's decompressed pages with fs-verity. */
1665 	for (i = 0; i < dic->cluster_size; i++) {
1666 		struct page *rpage = dic->rpages[i];
1667 
1668 		if (rpage && !fsverity_verify_page(rpage))
1669 			SetPageError(rpage);
1670 	}
1671 
1672 	__f2fs_decompress_end_io(dic, false);
1673 }
1674 
1675 /*
1676  * This is called when a compressed cluster has been decompressed
1677  * (or failed to be read and/or decompressed).
1678  */
1679 void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
1680 {
1681 	if (!failed && dic->need_verity) {
1682 		/*
1683 		 * Note that to avoid deadlocks, the verity work can't be done
1684 		 * on the decompression workqueue.  This is because verifying
1685 		 * the data pages can involve reading metadata pages from the
1686 		 * file, and these metadata pages may be compressed.
1687 		 */
1688 		INIT_WORK(&dic->verity_work, f2fs_verify_cluster);
1689 		fsverity_enqueue_verify_work(&dic->verity_work);
1690 	} else {
1691 		__f2fs_decompress_end_io(dic, failed);
1692 	}
1693 }
1694 
1695 /*
1696  * Put a reference to a compressed page's decompress_io_ctx.
1697  *
1698  * This is called when the page is no longer needed and can be freed.
1699  */
1700 void f2fs_put_page_dic(struct page *page)
1701 {
1702 	struct decompress_io_ctx *dic =
1703 			(struct decompress_io_ctx *)page_private(page);
1704 
1705 	f2fs_put_dic(dic);
1706 }
1707 
1708 int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi)
1709 {
1710 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1711 	char slab_name[32];
1712 
1713 	sprintf(slab_name, "f2fs_page_array_entry-%u:%u", MAJOR(dev), MINOR(dev));
1714 
1715 	sbi->page_array_slab_size = sizeof(struct page *) <<
1716 					F2FS_OPTION(sbi).compress_log_size;
1717 
1718 	sbi->page_array_slab = f2fs_kmem_cache_create(slab_name,
1719 					sbi->page_array_slab_size);
1720 	if (!sbi->page_array_slab)
1721 		return -ENOMEM;
1722 	return 0;
1723 }
1724 
1725 void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi)
1726 {
1727 	kmem_cache_destroy(sbi->page_array_slab);
1728 }
1729 
1730 static int __init f2fs_init_cic_cache(void)
1731 {
1732 	cic_entry_slab = f2fs_kmem_cache_create("f2fs_cic_entry",
1733 					sizeof(struct compress_io_ctx));
1734 	if (!cic_entry_slab)
1735 		return -ENOMEM;
1736 	return 0;
1737 }
1738 
1739 static void f2fs_destroy_cic_cache(void)
1740 {
1741 	kmem_cache_destroy(cic_entry_slab);
1742 }
1743 
1744 static int __init f2fs_init_dic_cache(void)
1745 {
1746 	dic_entry_slab = f2fs_kmem_cache_create("f2fs_dic_entry",
1747 					sizeof(struct decompress_io_ctx));
1748 	if (!dic_entry_slab)
1749 		return -ENOMEM;
1750 	return 0;
1751 }
1752 
1753 static void f2fs_destroy_dic_cache(void)
1754 {
1755 	kmem_cache_destroy(dic_entry_slab);
1756 }
1757 
1758 int __init f2fs_init_compress_cache(void)
1759 {
1760 	int err;
1761 
1762 	err = f2fs_init_cic_cache();
1763 	if (err)
1764 		goto out;
1765 	err = f2fs_init_dic_cache();
1766 	if (err)
1767 		goto free_cic;
1768 	return 0;
1769 free_cic:
1770 	f2fs_destroy_cic_cache();
1771 out:
1772 	return -ENOMEM;
1773 }
1774 
1775 void f2fs_destroy_compress_cache(void)
1776 {
1777 	f2fs_destroy_dic_cache();
1778 	f2fs_destroy_cic_cache();
1779 }
1780