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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#include "fs.h"
24#include "subpage.h"
25
26/* workspace buffer size for s390 zlib hardware support */
27#define ZLIB_DFLTCC_BUF_SIZE (4 * PAGE_SIZE)
28
29struct workspace {
30 z_stream strm;
31 char *buf;
32 unsigned int buf_size;
33 struct list_head list;
34 int level;
35};
36
37static struct workspace_manager wsm;
38
39struct list_head *zlib_get_workspace(unsigned int level)
40{
41 struct list_head *ws = btrfs_get_workspace(BTRFS_COMPRESS_ZLIB, level);
42 struct workspace *workspace = list_entry(ws, struct workspace, list);
43
44 workspace->level = level;
45
46 return ws;
47}
48
49void zlib_free_workspace(struct list_head *ws)
50{
51 struct workspace *workspace = list_entry(ws, struct workspace, list);
52
53 kvfree(workspace->strm.workspace);
54 kfree(workspace->buf);
55 kfree(workspace);
56}
57
58struct list_head *zlib_alloc_workspace(unsigned int level)
59{
60 struct workspace *workspace;
61 int workspacesize;
62
63 workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
64 if (!workspace)
65 return ERR_PTR(-ENOMEM);
66
67 workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
68 zlib_inflate_workspacesize());
69 workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL | __GFP_NOWARN);
70 workspace->level = level;
71 workspace->buf = NULL;
72 /*
73 * In case of s390 zlib hardware support, allocate lager workspace
74 * buffer. If allocator fails, fall back to a single page buffer.
75 */
76 if (zlib_deflate_dfltcc_enabled()) {
77 workspace->buf = kmalloc(ZLIB_DFLTCC_BUF_SIZE,
78 __GFP_NOMEMALLOC | __GFP_NORETRY |
79 __GFP_NOWARN | GFP_NOIO);
80 workspace->buf_size = ZLIB_DFLTCC_BUF_SIZE;
81 }
82 if (!workspace->buf) {
83 workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
84 workspace->buf_size = PAGE_SIZE;
85 }
86 if (!workspace->strm.workspace || !workspace->buf)
87 goto fail;
88
89 INIT_LIST_HEAD(&workspace->list);
90
91 return &workspace->list;
92fail:
93 zlib_free_workspace(&workspace->list);
94 return ERR_PTR(-ENOMEM);
95}
96
97int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
98 u64 start, struct folio **folios, unsigned long *out_folios,
99 unsigned long *total_in, unsigned long *total_out)
100{
101 struct workspace *workspace = list_entry(ws, struct workspace, list);
102 int ret;
103 char *data_in = NULL;
104 char *cfolio_out;
105 int nr_folios = 0;
106 struct folio *in_folio = NULL;
107 struct folio *out_folio = NULL;
108 unsigned long bytes_left;
109 unsigned int in_buf_folios;
110 unsigned long len = *total_out;
111 unsigned long nr_dest_folios = *out_folios;
112 const unsigned long max_out = nr_dest_folios * PAGE_SIZE;
113 const u64 orig_end = start + len;
114
115 *out_folios = 0;
116 *total_out = 0;
117 *total_in = 0;
118
119 ret = zlib_deflateInit(&workspace->strm, workspace->level);
120 if (unlikely(ret != Z_OK)) {
121 struct btrfs_inode *inode = BTRFS_I(mapping->host);
122
123 btrfs_err(inode->root->fs_info,
124 "zlib compression init failed, error %d root %llu inode %llu offset %llu",
125 ret, btrfs_root_id(inode->root), btrfs_ino(inode), start);
126 ret = -EIO;
127 goto out;
128 }
129
130 workspace->strm.total_in = 0;
131 workspace->strm.total_out = 0;
132
133 out_folio = btrfs_alloc_compr_folio();
134 if (out_folio == NULL) {
135 ret = -ENOMEM;
136 goto out;
137 }
138 cfolio_out = folio_address(out_folio);
139 folios[0] = out_folio;
140 nr_folios = 1;
141
142 workspace->strm.next_in = workspace->buf;
143 workspace->strm.avail_in = 0;
144 workspace->strm.next_out = cfolio_out;
145 workspace->strm.avail_out = PAGE_SIZE;
146
147 while (workspace->strm.total_in < len) {
148 /*
149 * Get next input pages and copy the contents to
150 * the workspace buffer if required.
151 */
152 if (workspace->strm.avail_in == 0) {
153 bytes_left = len - workspace->strm.total_in;
154 in_buf_folios = min(DIV_ROUND_UP(bytes_left, PAGE_SIZE),
155 workspace->buf_size / PAGE_SIZE);
156 if (in_buf_folios > 1) {
157 int i;
158
159 /* S390 hardware acceleration path, not subpage. */
160 ASSERT(!btrfs_is_subpage(
161 inode_to_fs_info(mapping->host),
162 mapping));
163 for (i = 0; i < in_buf_folios; i++) {
164 if (data_in) {
165 kunmap_local(data_in);
166 folio_put(in_folio);
167 data_in = NULL;
168 }
169 ret = btrfs_compress_filemap_get_folio(mapping,
170 start, &in_folio);
171 if (ret < 0)
172 goto out;
173 data_in = kmap_local_folio(in_folio, 0);
174 copy_page(workspace->buf + i * PAGE_SIZE,
175 data_in);
176 start += PAGE_SIZE;
177 }
178 workspace->strm.next_in = workspace->buf;
179 workspace->strm.avail_in = min(bytes_left,
180 in_buf_folios << PAGE_SHIFT);
181 } else {
182 unsigned int pg_off;
183 unsigned int cur_len;
184
185 if (data_in) {
186 kunmap_local(data_in);
187 folio_put(in_folio);
188 data_in = NULL;
189 }
190 ret = btrfs_compress_filemap_get_folio(mapping,
191 start, &in_folio);
192 if (ret < 0)
193 goto out;
194 pg_off = offset_in_page(start);
195 cur_len = btrfs_calc_input_length(orig_end, start);
196 data_in = kmap_local_folio(in_folio, pg_off);
197 start += cur_len;
198 workspace->strm.next_in = data_in;
199 workspace->strm.avail_in = cur_len;
200 }
201 }
202
203 ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
204 if (unlikely(ret != Z_OK)) {
205 struct btrfs_inode *inode = BTRFS_I(mapping->host);
206
207 btrfs_warn(inode->root->fs_info,
208 "zlib compression failed, error %d root %llu inode %llu offset %llu",
209 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
210 start);
211 zlib_deflateEnd(&workspace->strm);
212 ret = -EIO;
213 goto out;
214 }
215
216 /* we're making it bigger, give up */
217 if (workspace->strm.total_in > 8192 &&
218 workspace->strm.total_in <
219 workspace->strm.total_out) {
220 ret = -E2BIG;
221 goto out;
222 }
223 /* we need another page for writing out. Test this
224 * before the total_in so we will pull in a new page for
225 * the stream end if required
226 */
227 if (workspace->strm.avail_out == 0) {
228 if (nr_folios == nr_dest_folios) {
229 ret = -E2BIG;
230 goto out;
231 }
232 out_folio = btrfs_alloc_compr_folio();
233 if (out_folio == NULL) {
234 ret = -ENOMEM;
235 goto out;
236 }
237 cfolio_out = folio_address(out_folio);
238 folios[nr_folios] = out_folio;
239 nr_folios++;
240 workspace->strm.avail_out = PAGE_SIZE;
241 workspace->strm.next_out = cfolio_out;
242 }
243 /* we're all done */
244 if (workspace->strm.total_in >= len)
245 break;
246 if (workspace->strm.total_out > max_out)
247 break;
248 }
249 workspace->strm.avail_in = 0;
250 /*
251 * Call deflate with Z_FINISH flush parameter providing more output
252 * space but no more input data, until it returns with Z_STREAM_END.
253 */
254 while (ret != Z_STREAM_END) {
255 ret = zlib_deflate(&workspace->strm, Z_FINISH);
256 if (ret == Z_STREAM_END)
257 break;
258 if (ret != Z_OK && ret != Z_BUF_ERROR) {
259 zlib_deflateEnd(&workspace->strm);
260 ret = -EIO;
261 goto out;
262 } else if (workspace->strm.avail_out == 0) {
263 /* Get another folio for the stream end. */
264 if (nr_folios == nr_dest_folios) {
265 ret = -E2BIG;
266 goto out;
267 }
268 out_folio = btrfs_alloc_compr_folio();
269 if (out_folio == NULL) {
270 ret = -ENOMEM;
271 goto out;
272 }
273 cfolio_out = folio_address(out_folio);
274 folios[nr_folios] = out_folio;
275 nr_folios++;
276 workspace->strm.avail_out = PAGE_SIZE;
277 workspace->strm.next_out = cfolio_out;
278 }
279 }
280 zlib_deflateEnd(&workspace->strm);
281
282 if (workspace->strm.total_out >= workspace->strm.total_in) {
283 ret = -E2BIG;
284 goto out;
285 }
286
287 ret = 0;
288 *total_out = workspace->strm.total_out;
289 *total_in = workspace->strm.total_in;
290out:
291 *out_folios = nr_folios;
292 if (data_in) {
293 kunmap_local(data_in);
294 folio_put(in_folio);
295 }
296
297 return ret;
298}
299
300int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
301{
302 struct workspace *workspace = list_entry(ws, struct workspace, list);
303 int ret = 0, ret2;
304 int wbits = MAX_WBITS;
305 char *data_in;
306 size_t total_out = 0;
307 unsigned long folio_in_index = 0;
308 size_t srclen = cb->compressed_len;
309 unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
310 unsigned long buf_start;
311 struct folio **folios_in = cb->compressed_folios;
312
313 data_in = kmap_local_folio(folios_in[folio_in_index], 0);
314 workspace->strm.next_in = data_in;
315 workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
316 workspace->strm.total_in = 0;
317
318 workspace->strm.total_out = 0;
319 workspace->strm.next_out = workspace->buf;
320 workspace->strm.avail_out = workspace->buf_size;
321
322 /* If it's deflate, and it's got no preset dictionary, then
323 we can tell zlib to skip the adler32 check. */
324 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
325 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
326 !(((data_in[0]<<8) + data_in[1]) % 31)) {
327
328 wbits = -((data_in[0] >> 4) + 8);
329 workspace->strm.next_in += 2;
330 workspace->strm.avail_in -= 2;
331 }
332
333 ret = zlib_inflateInit2(&workspace->strm, wbits);
334 if (unlikely(ret != Z_OK)) {
335 struct btrfs_inode *inode = cb->bbio.inode;
336
337 kunmap_local(data_in);
338 btrfs_err(inode->root->fs_info,
339 "zlib decompression init failed, error %d root %llu inode %llu offset %llu",
340 ret, btrfs_root_id(inode->root), btrfs_ino(inode), cb->start);
341 return -EIO;
342 }
343 while (workspace->strm.total_in < srclen) {
344 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
345 if (ret != Z_OK && ret != Z_STREAM_END)
346 break;
347
348 buf_start = total_out;
349 total_out = workspace->strm.total_out;
350
351 /* we didn't make progress in this inflate call, we're done */
352 if (buf_start == total_out)
353 break;
354
355 ret2 = btrfs_decompress_buf2page(workspace->buf,
356 total_out - buf_start, cb, buf_start);
357 if (ret2 == 0) {
358 ret = 0;
359 goto done;
360 }
361
362 workspace->strm.next_out = workspace->buf;
363 workspace->strm.avail_out = workspace->buf_size;
364
365 if (workspace->strm.avail_in == 0) {
366 unsigned long tmp;
367 kunmap_local(data_in);
368 folio_in_index++;
369 if (folio_in_index >= total_folios_in) {
370 data_in = NULL;
371 break;
372 }
373 data_in = kmap_local_folio(folios_in[folio_in_index], 0);
374 workspace->strm.next_in = data_in;
375 tmp = srclen - workspace->strm.total_in;
376 workspace->strm.avail_in = min(tmp, PAGE_SIZE);
377 }
378 }
379 if (unlikely(ret != Z_STREAM_END)) {
380 btrfs_err(cb->bbio.inode->root->fs_info,
381 "zlib decompression failed, error %d root %llu inode %llu offset %llu",
382 ret, btrfs_root_id(cb->bbio.inode->root),
383 btrfs_ino(cb->bbio.inode), cb->start);
384 ret = -EIO;
385 } else {
386 ret = 0;
387 }
388done:
389 zlib_inflateEnd(&workspace->strm);
390 if (data_in)
391 kunmap_local(data_in);
392 return ret;
393}
394
395int zlib_decompress(struct list_head *ws, const u8 *data_in,
396 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
397 size_t destlen)
398{
399 struct workspace *workspace = list_entry(ws, struct workspace, list);
400 int ret = 0;
401 int wbits = MAX_WBITS;
402 unsigned long to_copy;
403
404 workspace->strm.next_in = data_in;
405 workspace->strm.avail_in = srclen;
406 workspace->strm.total_in = 0;
407
408 workspace->strm.next_out = workspace->buf;
409 workspace->strm.avail_out = workspace->buf_size;
410 workspace->strm.total_out = 0;
411 /* If it's deflate, and it's got no preset dictionary, then
412 we can tell zlib to skip the adler32 check. */
413 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
414 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
415 !(((data_in[0]<<8) + data_in[1]) % 31)) {
416
417 wbits = -((data_in[0] >> 4) + 8);
418 workspace->strm.next_in += 2;
419 workspace->strm.avail_in -= 2;
420 }
421
422 ret = zlib_inflateInit2(&workspace->strm, wbits);
423 if (unlikely(ret != Z_OK)) {
424 struct btrfs_inode *inode = folio_to_inode(dest_folio);
425
426 btrfs_err(inode->root->fs_info,
427 "zlib decompression init failed, error %d root %llu inode %llu offset %llu",
428 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
429 folio_pos(dest_folio));
430 return -EIO;
431 }
432
433 /*
434 * Everything (in/out buf) should be at most one sector, there should
435 * be no need to switch any input/output buffer.
436 */
437 ret = zlib_inflate(&workspace->strm, Z_FINISH);
438 to_copy = min(workspace->strm.total_out, destlen);
439 if (ret != Z_STREAM_END)
440 goto out;
441
442 memcpy_to_folio(dest_folio, dest_pgoff, workspace->buf, to_copy);
443
444out:
445 if (unlikely(to_copy != destlen)) {
446 struct btrfs_inode *inode = folio_to_inode(dest_folio);
447
448 btrfs_err(inode->root->fs_info,
449"zlib decompression failed, error %d root %llu inode %llu offset %llu decompressed %lu expected %zu",
450 ret, btrfs_root_id(inode->root), btrfs_ino(inode),
451 folio_pos(dest_folio), to_copy, destlen);
452 ret = -EIO;
453 } else {
454 ret = 0;
455 }
456
457 zlib_inflateEnd(&workspace->strm);
458
459 if (unlikely(to_copy < destlen))
460 folio_zero_range(dest_folio, dest_pgoff + to_copy, destlen - to_copy);
461 return ret;
462}
463
464const struct btrfs_compress_op btrfs_zlib_compress = {
465 .workspace_manager = &wsm,
466 .max_level = 9,
467 .default_level = BTRFS_ZLIB_DEFAULT_LEVEL,
468};
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 "compression.h"
22
23/* workspace buffer size for s390 zlib hardware support */
24#define ZLIB_DFLTCC_BUF_SIZE (4 * PAGE_SIZE)
25
26struct workspace {
27 z_stream strm;
28 char *buf;
29 unsigned int buf_size;
30 struct list_head list;
31 int level;
32};
33
34static struct workspace_manager wsm;
35
36struct list_head *zlib_get_workspace(unsigned int level)
37{
38 struct list_head *ws = btrfs_get_workspace(BTRFS_COMPRESS_ZLIB, level);
39 struct workspace *workspace = list_entry(ws, struct workspace, list);
40
41 workspace->level = level;
42
43 return ws;
44}
45
46void zlib_free_workspace(struct list_head *ws)
47{
48 struct workspace *workspace = list_entry(ws, struct workspace, list);
49
50 kvfree(workspace->strm.workspace);
51 kfree(workspace->buf);
52 kfree(workspace);
53}
54
55struct list_head *zlib_alloc_workspace(unsigned int level)
56{
57 struct workspace *workspace;
58 int workspacesize;
59
60 workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
61 if (!workspace)
62 return ERR_PTR(-ENOMEM);
63
64 workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
65 zlib_inflate_workspacesize());
66 workspace->strm.workspace = kvmalloc(workspacesize, GFP_KERNEL);
67 workspace->level = level;
68 workspace->buf = NULL;
69 /*
70 * In case of s390 zlib hardware support, allocate lager workspace
71 * buffer. If allocator fails, fall back to a single page buffer.
72 */
73 if (zlib_deflate_dfltcc_enabled()) {
74 workspace->buf = kmalloc(ZLIB_DFLTCC_BUF_SIZE,
75 __GFP_NOMEMALLOC | __GFP_NORETRY |
76 __GFP_NOWARN | GFP_NOIO);
77 workspace->buf_size = ZLIB_DFLTCC_BUF_SIZE;
78 }
79 if (!workspace->buf) {
80 workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
81 workspace->buf_size = PAGE_SIZE;
82 }
83 if (!workspace->strm.workspace || !workspace->buf)
84 goto fail;
85
86 INIT_LIST_HEAD(&workspace->list);
87
88 return &workspace->list;
89fail:
90 zlib_free_workspace(&workspace->list);
91 return ERR_PTR(-ENOMEM);
92}
93
94int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
95 u64 start, struct page **pages, unsigned long *out_pages,
96 unsigned long *total_in, unsigned long *total_out)
97{
98 struct workspace *workspace = list_entry(ws, struct workspace, list);
99 int ret;
100 char *data_in;
101 char *cpage_out;
102 int nr_pages = 0;
103 struct page *in_page = NULL;
104 struct page *out_page = NULL;
105 unsigned long bytes_left;
106 unsigned int in_buf_pages;
107 unsigned long len = *total_out;
108 unsigned long nr_dest_pages = *out_pages;
109 const unsigned long max_out = nr_dest_pages * PAGE_SIZE;
110
111 *out_pages = 0;
112 *total_out = 0;
113 *total_in = 0;
114
115 if (Z_OK != zlib_deflateInit(&workspace->strm, workspace->level)) {
116 pr_warn("BTRFS: deflateInit failed\n");
117 ret = -EIO;
118 goto out;
119 }
120
121 workspace->strm.total_in = 0;
122 workspace->strm.total_out = 0;
123
124 out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
125 if (out_page == NULL) {
126 ret = -ENOMEM;
127 goto out;
128 }
129 cpage_out = kmap(out_page);
130 pages[0] = out_page;
131 nr_pages = 1;
132
133 workspace->strm.next_in = workspace->buf;
134 workspace->strm.avail_in = 0;
135 workspace->strm.next_out = cpage_out;
136 workspace->strm.avail_out = PAGE_SIZE;
137
138 while (workspace->strm.total_in < len) {
139 /*
140 * Get next input pages and copy the contents to
141 * the workspace buffer if required.
142 */
143 if (workspace->strm.avail_in == 0) {
144 bytes_left = len - workspace->strm.total_in;
145 in_buf_pages = min(DIV_ROUND_UP(bytes_left, PAGE_SIZE),
146 workspace->buf_size / PAGE_SIZE);
147 if (in_buf_pages > 1) {
148 int i;
149
150 for (i = 0; i < in_buf_pages; i++) {
151 if (in_page) {
152 kunmap(in_page);
153 put_page(in_page);
154 }
155 in_page = find_get_page(mapping,
156 start >> PAGE_SHIFT);
157 data_in = kmap(in_page);
158 memcpy(workspace->buf + i * PAGE_SIZE,
159 data_in, PAGE_SIZE);
160 start += PAGE_SIZE;
161 }
162 workspace->strm.next_in = workspace->buf;
163 } else {
164 if (in_page) {
165 kunmap(in_page);
166 put_page(in_page);
167 }
168 in_page = find_get_page(mapping,
169 start >> PAGE_SHIFT);
170 data_in = kmap(in_page);
171 start += PAGE_SIZE;
172 workspace->strm.next_in = data_in;
173 }
174 workspace->strm.avail_in = min(bytes_left,
175 (unsigned long) workspace->buf_size);
176 }
177
178 ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
179 if (ret != Z_OK) {
180 pr_debug("BTRFS: deflate in loop returned %d\n",
181 ret);
182 zlib_deflateEnd(&workspace->strm);
183 ret = -EIO;
184 goto out;
185 }
186
187 /* we're making it bigger, give up */
188 if (workspace->strm.total_in > 8192 &&
189 workspace->strm.total_in <
190 workspace->strm.total_out) {
191 ret = -E2BIG;
192 goto out;
193 }
194 /* we need another page for writing out. Test this
195 * before the total_in so we will pull in a new page for
196 * the stream end if required
197 */
198 if (workspace->strm.avail_out == 0) {
199 kunmap(out_page);
200 if (nr_pages == nr_dest_pages) {
201 out_page = NULL;
202 ret = -E2BIG;
203 goto out;
204 }
205 out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
206 if (out_page == NULL) {
207 ret = -ENOMEM;
208 goto out;
209 }
210 cpage_out = kmap(out_page);
211 pages[nr_pages] = out_page;
212 nr_pages++;
213 workspace->strm.avail_out = PAGE_SIZE;
214 workspace->strm.next_out = cpage_out;
215 }
216 /* we're all done */
217 if (workspace->strm.total_in >= len)
218 break;
219 if (workspace->strm.total_out > max_out)
220 break;
221 }
222 workspace->strm.avail_in = 0;
223 /*
224 * Call deflate with Z_FINISH flush parameter providing more output
225 * space but no more input data, until it returns with Z_STREAM_END.
226 */
227 while (ret != Z_STREAM_END) {
228 ret = zlib_deflate(&workspace->strm, Z_FINISH);
229 if (ret == Z_STREAM_END)
230 break;
231 if (ret != Z_OK && ret != Z_BUF_ERROR) {
232 zlib_deflateEnd(&workspace->strm);
233 ret = -EIO;
234 goto out;
235 } else if (workspace->strm.avail_out == 0) {
236 /* get another page for the stream end */
237 kunmap(out_page);
238 if (nr_pages == nr_dest_pages) {
239 out_page = NULL;
240 ret = -E2BIG;
241 goto out;
242 }
243 out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
244 if (out_page == NULL) {
245 ret = -ENOMEM;
246 goto out;
247 }
248 cpage_out = kmap(out_page);
249 pages[nr_pages] = out_page;
250 nr_pages++;
251 workspace->strm.avail_out = PAGE_SIZE;
252 workspace->strm.next_out = cpage_out;
253 }
254 }
255 zlib_deflateEnd(&workspace->strm);
256
257 if (workspace->strm.total_out >= workspace->strm.total_in) {
258 ret = -E2BIG;
259 goto out;
260 }
261
262 ret = 0;
263 *total_out = workspace->strm.total_out;
264 *total_in = workspace->strm.total_in;
265out:
266 *out_pages = nr_pages;
267 if (out_page)
268 kunmap(out_page);
269
270 if (in_page) {
271 kunmap(in_page);
272 put_page(in_page);
273 }
274 return ret;
275}
276
277int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
278{
279 struct workspace *workspace = list_entry(ws, struct workspace, list);
280 int ret = 0, ret2;
281 int wbits = MAX_WBITS;
282 char *data_in;
283 size_t total_out = 0;
284 unsigned long page_in_index = 0;
285 size_t srclen = cb->compressed_len;
286 unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
287 unsigned long buf_start;
288 struct page **pages_in = cb->compressed_pages;
289 u64 disk_start = cb->start;
290 struct bio *orig_bio = cb->orig_bio;
291
292 data_in = kmap(pages_in[page_in_index]);
293 workspace->strm.next_in = data_in;
294 workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
295 workspace->strm.total_in = 0;
296
297 workspace->strm.total_out = 0;
298 workspace->strm.next_out = workspace->buf;
299 workspace->strm.avail_out = workspace->buf_size;
300
301 /* If it's deflate, and it's got no preset dictionary, then
302 we can tell zlib to skip the adler32 check. */
303 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
304 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
305 !(((data_in[0]<<8) + data_in[1]) % 31)) {
306
307 wbits = -((data_in[0] >> 4) + 8);
308 workspace->strm.next_in += 2;
309 workspace->strm.avail_in -= 2;
310 }
311
312 if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
313 pr_warn("BTRFS: inflateInit failed\n");
314 kunmap(pages_in[page_in_index]);
315 return -EIO;
316 }
317 while (workspace->strm.total_in < srclen) {
318 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
319 if (ret != Z_OK && ret != Z_STREAM_END)
320 break;
321
322 buf_start = total_out;
323 total_out = workspace->strm.total_out;
324
325 /* we didn't make progress in this inflate call, we're done */
326 if (buf_start == total_out)
327 break;
328
329 ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
330 total_out, disk_start,
331 orig_bio);
332 if (ret2 == 0) {
333 ret = 0;
334 goto done;
335 }
336
337 workspace->strm.next_out = workspace->buf;
338 workspace->strm.avail_out = workspace->buf_size;
339
340 if (workspace->strm.avail_in == 0) {
341 unsigned long tmp;
342 kunmap(pages_in[page_in_index]);
343 page_in_index++;
344 if (page_in_index >= total_pages_in) {
345 data_in = NULL;
346 break;
347 }
348 data_in = kmap(pages_in[page_in_index]);
349 workspace->strm.next_in = data_in;
350 tmp = srclen - workspace->strm.total_in;
351 workspace->strm.avail_in = min(tmp,
352 PAGE_SIZE);
353 }
354 }
355 if (ret != Z_STREAM_END)
356 ret = -EIO;
357 else
358 ret = 0;
359done:
360 zlib_inflateEnd(&workspace->strm);
361 if (data_in)
362 kunmap(pages_in[page_in_index]);
363 if (!ret)
364 zero_fill_bio(orig_bio);
365 return ret;
366}
367
368int zlib_decompress(struct list_head *ws, unsigned char *data_in,
369 struct page *dest_page, unsigned long start_byte, size_t srclen,
370 size_t destlen)
371{
372 struct workspace *workspace = list_entry(ws, struct workspace, list);
373 int ret = 0;
374 int wbits = MAX_WBITS;
375 unsigned long bytes_left;
376 unsigned long total_out = 0;
377 unsigned long pg_offset = 0;
378
379 destlen = min_t(unsigned long, destlen, PAGE_SIZE);
380 bytes_left = destlen;
381
382 workspace->strm.next_in = data_in;
383 workspace->strm.avail_in = srclen;
384 workspace->strm.total_in = 0;
385
386 workspace->strm.next_out = workspace->buf;
387 workspace->strm.avail_out = workspace->buf_size;
388 workspace->strm.total_out = 0;
389 /* If it's deflate, and it's got no preset dictionary, then
390 we can tell zlib to skip the adler32 check. */
391 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
392 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
393 !(((data_in[0]<<8) + data_in[1]) % 31)) {
394
395 wbits = -((data_in[0] >> 4) + 8);
396 workspace->strm.next_in += 2;
397 workspace->strm.avail_in -= 2;
398 }
399
400 if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
401 pr_warn("BTRFS: inflateInit failed\n");
402 return -EIO;
403 }
404
405 while (bytes_left > 0) {
406 unsigned long buf_start;
407 unsigned long buf_offset;
408 unsigned long bytes;
409
410 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
411 if (ret != Z_OK && ret != Z_STREAM_END)
412 break;
413
414 buf_start = total_out;
415 total_out = workspace->strm.total_out;
416
417 if (total_out == buf_start) {
418 ret = -EIO;
419 break;
420 }
421
422 if (total_out <= start_byte)
423 goto next;
424
425 if (total_out > start_byte && buf_start < start_byte)
426 buf_offset = start_byte - buf_start;
427 else
428 buf_offset = 0;
429
430 bytes = min(PAGE_SIZE - pg_offset,
431 PAGE_SIZE - (buf_offset % PAGE_SIZE));
432 bytes = min(bytes, bytes_left);
433
434 memcpy_to_page(dest_page, pg_offset,
435 workspace->buf + buf_offset, bytes);
436
437 pg_offset += bytes;
438 bytes_left -= bytes;
439next:
440 workspace->strm.next_out = workspace->buf;
441 workspace->strm.avail_out = workspace->buf_size;
442 }
443
444 if (ret != Z_STREAM_END && bytes_left != 0)
445 ret = -EIO;
446 else
447 ret = 0;
448
449 zlib_inflateEnd(&workspace->strm);
450
451 /*
452 * this should only happen if zlib returned fewer bytes than we
453 * expected. btrfs_get_block is responsible for zeroing from the
454 * end of the inline extent (destlen) to the end of the page
455 */
456 if (pg_offset < destlen) {
457 memzero_page(dest_page, pg_offset, destlen - pg_offset);
458 }
459 return ret;
460}
461
462const struct btrfs_compress_op btrfs_zlib_compress = {
463 .workspace_manager = &wsm,
464 .max_level = 9,
465 .default_level = BTRFS_ZLIB_DEFAULT_LEVEL,
466};