device-dax/kmem: use struct_size()
[linux-2.6-microblaze.git] / fs / btrfs / zlib.c
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
26 struct workspace {
27         z_stream strm;
28         char *buf;
29         unsigned int buf_size;
30         struct list_head list;
31         int level;
32 };
33
34 static struct workspace_manager wsm;
35
36 struct 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
46 void 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
55 struct 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;
89 fail:
90         zlib_free_workspace(&workspace->list);
91         return ERR_PTR(-ENOMEM);
92 }
93
94 int 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;
265 out:
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
277 int 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;
359 done:
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
368 int 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         char *kaddr;
379
380         destlen = min_t(unsigned long, destlen, PAGE_SIZE);
381         bytes_left = destlen;
382
383         workspace->strm.next_in = data_in;
384         workspace->strm.avail_in = srclen;
385         workspace->strm.total_in = 0;
386
387         workspace->strm.next_out = workspace->buf;
388         workspace->strm.avail_out = workspace->buf_size;
389         workspace->strm.total_out = 0;
390         /* If it's deflate, and it's got no preset dictionary, then
391            we can tell zlib to skip the adler32 check. */
392         if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
393             ((data_in[0] & 0x0f) == Z_DEFLATED) &&
394             !(((data_in[0]<<8) + data_in[1]) % 31)) {
395
396                 wbits = -((data_in[0] >> 4) + 8);
397                 workspace->strm.next_in += 2;
398                 workspace->strm.avail_in -= 2;
399         }
400
401         if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
402                 pr_warn("BTRFS: inflateInit failed\n");
403                 return -EIO;
404         }
405
406         while (bytes_left > 0) {
407                 unsigned long buf_start;
408                 unsigned long buf_offset;
409                 unsigned long bytes;
410
411                 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
412                 if (ret != Z_OK && ret != Z_STREAM_END)
413                         break;
414
415                 buf_start = total_out;
416                 total_out = workspace->strm.total_out;
417
418                 if (total_out == buf_start) {
419                         ret = -EIO;
420                         break;
421                 }
422
423                 if (total_out <= start_byte)
424                         goto next;
425
426                 if (total_out > start_byte && buf_start < start_byte)
427                         buf_offset = start_byte - buf_start;
428                 else
429                         buf_offset = 0;
430
431                 bytes = min(PAGE_SIZE - pg_offset,
432                             PAGE_SIZE - (buf_offset % PAGE_SIZE));
433                 bytes = min(bytes, bytes_left);
434
435                 kaddr = kmap_atomic(dest_page);
436                 memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes);
437                 kunmap_atomic(kaddr);
438
439                 pg_offset += bytes;
440                 bytes_left -= bytes;
441 next:
442                 workspace->strm.next_out = workspace->buf;
443                 workspace->strm.avail_out = workspace->buf_size;
444         }
445
446         if (ret != Z_STREAM_END && bytes_left != 0)
447                 ret = -EIO;
448         else
449                 ret = 0;
450
451         zlib_inflateEnd(&workspace->strm);
452
453         /*
454          * this should only happen if zlib returned fewer bytes than we
455          * expected.  btrfs_get_block is responsible for zeroing from the
456          * end of the inline extent (destlen) to the end of the page
457          */
458         if (pg_offset < destlen) {
459                 kaddr = kmap_atomic(dest_page);
460                 memset(kaddr + pg_offset, 0, destlen - pg_offset);
461                 kunmap_atomic(kaddr);
462         }
463         return ret;
464 }
465
466 const struct btrfs_compress_op btrfs_zlib_compress = {
467         .workspace_manager      = &wsm,
468         .max_level              = 9,
469         .default_level          = BTRFS_ZLIB_DEFAULT_LEVEL,
470 };