1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Oracle. All rights reserved.
4 *
5 * Based on jffs2 zlib code:
6 * Copyright © 2001-2007 Red Hat, Inc.
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/zlib.h>
13 #include <linux/zutil.h>
14 #include <linux/mm.h>
15 #include <linux/init.h>
16 #include <linux/err.h>
17 #include <linux/sched.h>
18 #include <linux/pagemap.h>
19 #include <linux/bio.h>
20 #include <linux/refcount.h>
21 #include "btrfs_inode.h"
22 #include "compression.h"
23
24 /* workspace buffer size for s390 zlib hardware support */
25 #define ZLIB_DFLTCC_BUF_SIZE (4 * PAGE_SIZE)
26
27 struct workspace {
28 z_stream strm;
29 char *buf;
30 unsigned int buf_size;
31 struct list_head list;
32 int level;
33 };
34
35 static struct workspace_manager wsm;
36
37 struct list_head *zlib_get_workspace(unsigned int level)
38 {
39 struct list_head *ws = btrfs_get_workspace(BTRFS_COMPRESS_ZLIB, level);
40 struct workspace *workspace = list_entry(ws, struct workspace, list);
41
42 workspace->level = level;
43
44 return ws;
45 }
46
47 void zlib_free_workspace(struct list_head *ws)
48 {
49 struct workspace *workspace = list_entry(ws, struct workspace, list);
50
51 kvfree(workspace->strm.workspace);
52 kfree(workspace->buf);
53 kfree(workspace);
54 }
55
56 struct list_head *zlib_alloc_workspace(unsigned int level)
57 {
58 struct workspace *workspace;
59 int workspacesize;
60
61 workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
62 if (!workspace)
63 return ERR_PTR(-ENOMEM);
64
65 workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
66 zlib_inflate_workspacesize());
67 workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL | __GFP_NOWARN);
68 workspace->level = level;
69 workspace->buf = NULL;
70 /*
71 * In case of s390 zlib hardware support, allocate lager workspace
72 * buffer. If allocator fails, fall back to a single page buffer.
73 */
74 if (zlib_deflate_dfltcc_enabled()) {
75 workspace->buf = kmalloc(ZLIB_DFLTCC_BUF_SIZE,
76 __GFP_NOMEMALLOC | __GFP_NORETRY |
77 __GFP_NOWARN | GFP_NOIO);
78 workspace->buf_size = ZLIB_DFLTCC_BUF_SIZE;
79 }
80 if (!workspace->buf) {
81 workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
82 workspace->buf_size = PAGE_SIZE;
83 }
84 if (!workspace->strm.workspace || !workspace->buf)
85 goto fail;
86
87 INIT_LIST_HEAD(&workspace->list);
88
89 return &workspace->list;
90 fail:
91 zlib_free_workspace(&workspace->list);
92 return ERR_PTR(-ENOMEM);
93 }
94
95 int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
96 u64 start, struct folio **folios, unsigned long *out_folios,
97 unsigned long *total_in, unsigned long *total_out)
98 {
99 struct workspace *workspace = list_entry(ws, struct workspace, list);
100 int ret;
101 char *data_in = NULL;
102 char *cfolio_out;
103 int nr_folios = 0;
104 struct folio *in_folio = NULL;
105 struct folio *out_folio = NULL;
106 unsigned long bytes_left;
107 unsigned int in_buf_folios;
108 unsigned long len = *total_out;
109 unsigned long nr_dest_folios = *out_folios;
110 const unsigned long max_out = nr_dest_folios * PAGE_SIZE;
111
112 *out_folios = 0;
113 *total_out = 0;
114 *total_in = 0;
115
116 ret = zlib_deflateInit(&workspace->strm, workspace->level);
117 if (unlikely(ret != Z_OK)) {
118 struct btrfs_inode *inode = BTRFS_I(mapping->host);
119
120 btrfs_err(inode->root->fs_info,
121 "zlib compression init failed, error %d root %llu inode %llu offset %llu",
122 ret, btrfs_root_id(inode->root), btrfs_ino(inode), start);
123 ret = -EIO;
124 goto out;
125 }
126
127 workspace->strm.total_in = 0;
128 workspace->strm.total_out = 0;
129
130 out_folio = btrfs_alloc_compr_folio();
131 if (out_folio == NULL) {
132 ret = -ENOMEM;
133 goto out;
134 }
135 cfolio_out = folio_address(out_folio);
136 folios[0] = out_folio;
137 nr_folios = 1;
138
139 workspace->strm.next_in = workspace->buf;
140 workspace->strm.avail_in = 0;
141 workspace->strm.next_out = cfolio_out;
142 workspace->strm.avail_out = PAGE_SIZE;
143
144 while (workspace->strm.total_in < len) {
145 /*
146 * Get next input pages and copy the contents to
147 * the workspace buffer if required.
148 */
149 if (workspace->strm.avail_in == 0) {
150 bytes_left = len - workspace->strm.total_in;
151 in_buf_folios = min(DIV_ROUND_UP(bytes_left, PAGE_SIZE),
152 workspace->buf_size / PAGE_SIZE);
153 if (in_buf_folios > 1) {
154 int i;
155
156 for (i = 0; i < in_buf_folios; i++) {
157 if (data_in) {
158 kunmap_local(data_in);
159 folio_put(in_folio);
160 data_in = NULL;
161 }
162 ret = btrfs_compress_filemap_get_folio(mapping,
163 start, &in_folio);
164 if (ret < 0)
165 goto out;
166 data_in = kmap_local_folio(in_folio, 0);
167 copy_page(workspace->buf + i * PAGE_SIZE,
168 data_in);
169 start += PAGE_SIZE;
170 }
171 workspace->strm.next_in = workspace->buf;
172 } else {
173 if (data_in) {
174 kunmap_local(data_in);
175 folio_put(in_folio);
176 data_in = NULL;
177 }
178 ret = btrfs_compress_filemap_get_folio(mapping,
179 start, &in_folio);
180 if (ret < 0)
181 goto out;
182 data_in = kmap_local_folio(in_folio, 0);
183 start += PAGE_SIZE;
184 workspace->strm.next_in = data_in;
185 }
186 workspace->strm.avail_in = min(bytes_left,
187 (unsigned long) workspace->buf_size);
188 }
189
190 ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
191 if (unlikely(ret != Z_OK)) {
192 struct btrfs_inode *inode = BTRFS_I(mapping->host);
193
194 btrfs_warn(inode->root->fs_info,
195 "zlib compression failed, error %d root %llu inode %llu offset %llu",
196 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
197 start);
198 zlib_deflateEnd(&workspace->strm);
199 ret = -EIO;
200 goto out;
201 }
202
203 /* we're making it bigger, give up */
204 if (workspace->strm.total_in > 8192 &&
205 workspace->strm.total_in <
206 workspace->strm.total_out) {
207 ret = -E2BIG;
208 goto out;
209 }
210 /* we need another page for writing out. Test this
211 * before the total_in so we will pull in a new page for
212 * the stream end if required
213 */
214 if (workspace->strm.avail_out == 0) {
215 if (nr_folios == nr_dest_folios) {
216 ret = -E2BIG;
217 goto out;
218 }
219 out_folio = btrfs_alloc_compr_folio();
220 if (out_folio == NULL) {
221 ret = -ENOMEM;
222 goto out;
223 }
224 cfolio_out = folio_address(out_folio);
225 folios[nr_folios] = out_folio;
226 nr_folios++;
227 workspace->strm.avail_out = PAGE_SIZE;
228 workspace->strm.next_out = cfolio_out;
229 }
230 /* we're all done */
231 if (workspace->strm.total_in >= len)
232 break;
233 if (workspace->strm.total_out > max_out)
234 break;
235 }
236 workspace->strm.avail_in = 0;
237 /*
238 * Call deflate with Z_FINISH flush parameter providing more output
239 * space but no more input data, until it returns with Z_STREAM_END.
240 */
241 while (ret != Z_STREAM_END) {
242 ret = zlib_deflate(&workspace->strm, Z_FINISH);
243 if (ret == Z_STREAM_END)
244 break;
245 if (ret != Z_OK && ret != Z_BUF_ERROR) {
246 zlib_deflateEnd(&workspace->strm);
247 ret = -EIO;
248 goto out;
249 } else if (workspace->strm.avail_out == 0) {
250 /* Get another folio for the stream end. */
251 if (nr_folios == nr_dest_folios) {
252 ret = -E2BIG;
253 goto out;
254 }
255 out_folio = btrfs_alloc_compr_folio();
256 if (out_folio == NULL) {
257 ret = -ENOMEM;
258 goto out;
259 }
260 cfolio_out = folio_address(out_folio);
261 folios[nr_folios] = out_folio;
262 nr_folios++;
263 workspace->strm.avail_out = PAGE_SIZE;
264 workspace->strm.next_out = cfolio_out;
265 }
266 }
267 zlib_deflateEnd(&workspace->strm);
268
269 if (workspace->strm.total_out >= workspace->strm.total_in) {
270 ret = -E2BIG;
271 goto out;
272 }
273
274 ret = 0;
275 *total_out = workspace->strm.total_out;
276 *total_in = workspace->strm.total_in;
277 out:
278 *out_folios = nr_folios;
279 if (data_in) {
280 kunmap_local(data_in);
281 folio_put(in_folio);
282 }
283
284 return ret;
285 }
286
287 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
288 {
289 struct workspace *workspace = list_entry(ws, struct workspace, list);
290 int ret = 0, ret2;
291 int wbits = MAX_WBITS;
292 char *data_in;
293 size_t total_out = 0;
294 unsigned long folio_in_index = 0;
295 size_t srclen = cb->compressed_len;
296 unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
297 unsigned long buf_start;
298 struct folio **folios_in = cb->compressed_folios;
299
300 data_in = kmap_local_folio(folios_in[folio_in_index], 0);
301 workspace->strm.next_in = data_in;
302 workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
303 workspace->strm.total_in = 0;
304
305 workspace->strm.total_out = 0;
306 workspace->strm.next_out = workspace->buf;
307 workspace->strm.avail_out = workspace->buf_size;
308
309 /* If it's deflate, and it's got no preset dictionary, then
310 we can tell zlib to skip the adler32 check. */
311 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
312 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
313 !(((data_in[0]<<8) + data_in[1]) % 31)) {
314
315 wbits = -((data_in[0] >> 4) + 8);
316 workspace->strm.next_in += 2;
317 workspace->strm.avail_in -= 2;
318 }
319
320 ret = zlib_inflateInit2(&workspace->strm, wbits);
321 if (unlikely(ret != Z_OK)) {
322 struct btrfs_inode *inode = cb->bbio.inode;
323
324 kunmap_local(data_in);
325 btrfs_err(inode->root->fs_info,
326 "zlib decompression init failed, error %d root %llu inode %llu offset %llu",
327 ret, btrfs_root_id(inode->root), btrfs_ino(inode), cb->start);
328 return -EIO;
329 }
330 while (workspace->strm.total_in < srclen) {
331 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
332 if (ret != Z_OK && ret != Z_STREAM_END)
333 break;
334
335 buf_start = total_out;
336 total_out = workspace->strm.total_out;
337
338 /* we didn't make progress in this inflate call, we're done */
339 if (buf_start == total_out)
340 break;
341
342 ret2 = btrfs_decompress_buf2page(workspace->buf,
343 total_out - buf_start, cb, buf_start);
344 if (ret2 == 0) {
345 ret = 0;
346 goto done;
347 }
348
349 workspace->strm.next_out = workspace->buf;
350 workspace->strm.avail_out = workspace->buf_size;
351
352 if (workspace->strm.avail_in == 0) {
353 unsigned long tmp;
354 kunmap_local(data_in);
355 folio_in_index++;
356 if (folio_in_index >= total_folios_in) {
357 data_in = NULL;
358 break;
359 }
360 data_in = kmap_local_folio(folios_in[folio_in_index], 0);
361 workspace->strm.next_in = data_in;
362 tmp = srclen - workspace->strm.total_in;
363 workspace->strm.avail_in = min(tmp, PAGE_SIZE);
364 }
365 }
366 if (unlikely(ret != Z_STREAM_END)) {
367 btrfs_err(cb->bbio.inode->root->fs_info,
368 "zlib decompression failed, error %d root %llu inode %llu offset %llu",
369 ret, btrfs_root_id(cb->bbio.inode->root),
370 btrfs_ino(cb->bbio.inode), cb->start);
371 ret = -EIO;
372 } else {
373 ret = 0;
374 }
375 done:
376 zlib_inflateEnd(&workspace->strm);
377 if (data_in)
378 kunmap_local(data_in);
379 return ret;
380 }
381
382 int zlib_decompress(struct list_head *ws, const u8 *data_in,
383 struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
384 size_t destlen)
385 {
386 struct workspace *workspace = list_entry(ws, struct workspace, list);
387 int ret = 0;
388 int wbits = MAX_WBITS;
389 unsigned long to_copy;
390
391 workspace->strm.next_in = data_in;
392 workspace->strm.avail_in = srclen;
393 workspace->strm.total_in = 0;
394
395 workspace->strm.next_out = workspace->buf;
396 workspace->strm.avail_out = workspace->buf_size;
397 workspace->strm.total_out = 0;
398 /* If it's deflate, and it's got no preset dictionary, then
399 we can tell zlib to skip the adler32 check. */
400 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
401 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
402 !(((data_in[0]<<8) + data_in[1]) % 31)) {
403
404 wbits = -((data_in[0] >> 4) + 8);
405 workspace->strm.next_in += 2;
406 workspace->strm.avail_in -= 2;
407 }
408
409 ret = zlib_inflateInit2(&workspace->strm, wbits);
410 if (unlikely(ret != Z_OK)) {
411 struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
412
413 btrfs_err(inode->root->fs_info,
414 "zlib decompression init failed, error %d root %llu inode %llu offset %llu",
415 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
416 page_offset(dest_page));
417 return -EIO;
418 }
419
420 /*
421 * Everything (in/out buf) should be at most one sector, there should
422 * be no need to switch any input/output buffer.
423 */
424 ret = zlib_inflate(&workspace->strm, Z_FINISH);
425 to_copy = min(workspace->strm.total_out, destlen);
426 if (ret != Z_STREAM_END)
427 goto out;
428
429 memcpy_to_page(dest_page, dest_pgoff, workspace->buf, to_copy);
430
431 out:
432 if (unlikely(to_copy != destlen)) {
433 struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
434
435 btrfs_err(inode->root->fs_info,
436 "zlib decompression failed, error %d root %llu inode %llu offset %llu decompressed %lu expected %zu",
437 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
438 page_offset(dest_page), to_copy, destlen);
439 ret = -EIO;
440 } else {
441 ret = 0;
442 }
443
444 zlib_inflateEnd(&workspace->strm);
445
446 if (unlikely(to_copy < destlen))
447 memzero_page(dest_page, dest_pgoff + to_copy, destlen - to_copy);
448 return ret;
449 }
450
451 const struct btrfs_compress_op btrfs_zlib_compress = {
452 .workspace_manager = &wsm,
453 .max_level = 9,
454 .default_level = BTRFS_ZLIB_DEFAULT_LEVEL,
455 };
456
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