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