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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2008 Oracle. All rights reserved.4 */5 6#include <linux/kernel.h>7#include <linux/slab.h>8#include <linux/mm.h>9#include <linux/init.h>10#include <linux/err.h>11#include <linux/sched.h>12#include <linux/pagemap.h>13#include <linux/bio.h>14#include <linux/lzo.h>15#include <linux/refcount.h>16#include "messages.h"17#include "compression.h"18#include "ctree.h"19#include "super.h"20#include "btrfs_inode.h"21 22#define LZO_LEN 423 24/*25 * Btrfs LZO compression format26 *27 * Regular and inlined LZO compressed data extents consist of:28 *29 * 1. Header30 * Fixed size. LZO_LEN (4) bytes long, LE32.31 * Records the total size (including the header) of compressed data.32 *33 * 2. Segment(s)34 * Variable size. Each segment includes one segment header, followed by data35 * payload.36 * One regular LZO compressed extent can have one or more segments.37 * For inlined LZO compressed extent, only one segment is allowed.38 * One segment represents at most one sector of uncompressed data.39 *40 * 2.1 Segment header41 * Fixed size. LZO_LEN (4) bytes long, LE32.42 * Records the total size of the segment (not including the header).43 * Segment header never crosses sector boundary, thus it's possible to44 * have at most 3 padding zeros at the end of the sector.45 *46 * 2.2 Data Payload47 * Variable size. Size up limit should be lzo1x_worst_compress(sectorsize)48 * which is 4419 for a 4KiB sectorsize.49 *50 * Example with 4K sectorsize:51 * Page 1:52 * 0 0x2 0x4 0x6 0x8 0xa 0xc 0xe 0x1053 * 0x0000 | Header | SegHdr 01 | Data payload 01 ... |54 * ...55 * 0x0ff0 | SegHdr N | Data payload N ... |00|56 * ^^ padding zeros57 * Page 2:58 * 0x1000 | SegHdr N+1| Data payload N+1 ... |59 */60 61#define WORKSPACE_BUF_LENGTH (lzo1x_worst_compress(PAGE_SIZE))62#define WORKSPACE_CBUF_LENGTH (lzo1x_worst_compress(PAGE_SIZE))63 64struct workspace {65 void *mem;66 void *buf; /* where decompressed data goes */67 void *cbuf; /* where compressed data goes */68 struct list_head list;69};70 71static struct workspace_manager wsm;72 73void lzo_free_workspace(struct list_head *ws)74{75 struct workspace *workspace = list_entry(ws, struct workspace, list);76 77 kvfree(workspace->buf);78 kvfree(workspace->cbuf);79 kvfree(workspace->mem);80 kfree(workspace);81}82 83struct list_head *lzo_alloc_workspace(unsigned int level)84{85 struct workspace *workspace;86 87 workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);88 if (!workspace)89 return ERR_PTR(-ENOMEM);90 91 workspace->mem = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL | __GFP_NOWARN);92 workspace->buf = kvmalloc(WORKSPACE_BUF_LENGTH, GFP_KERNEL | __GFP_NOWARN);93 workspace->cbuf = kvmalloc(WORKSPACE_CBUF_LENGTH, GFP_KERNEL | __GFP_NOWARN);94 if (!workspace->mem || !workspace->buf || !workspace->cbuf)95 goto fail;96 97 INIT_LIST_HEAD(&workspace->list);98 99 return &workspace->list;100fail:101 lzo_free_workspace(&workspace->list);102 return ERR_PTR(-ENOMEM);103}104 105static inline void write_compress_length(char *buf, size_t len)106{107 __le32 dlen;108 109 dlen = cpu_to_le32(len);110 memcpy(buf, &dlen, LZO_LEN);111}112 113static inline size_t read_compress_length(const char *buf)114{115 __le32 dlen;116 117 memcpy(&dlen, buf, LZO_LEN);118 return le32_to_cpu(dlen);119}120 121/*122 * Will do:123 *124 * - Write a segment header into the destination125 * - Copy the compressed buffer into the destination126 * - Make sure we have enough space in the last sector to fit a segment header127 * If not, we will pad at most (LZO_LEN (4)) - 1 bytes of zeros.128 *129 * Will allocate new pages when needed.130 */131static int copy_compressed_data_to_page(char *compressed_data,132 size_t compressed_size,133 struct folio **out_folios,134 unsigned long max_nr_folio,135 u32 *cur_out,136 const u32 sectorsize)137{138 u32 sector_bytes_left;139 u32 orig_out;140 struct folio *cur_folio;141 char *kaddr;142 143 if ((*cur_out / PAGE_SIZE) >= max_nr_folio)144 return -E2BIG;145 146 /*147 * We never allow a segment header crossing sector boundary, previous148 * run should ensure we have enough space left inside the sector.149 */150 ASSERT((*cur_out / sectorsize) == (*cur_out + LZO_LEN - 1) / sectorsize);151 152 cur_folio = out_folios[*cur_out / PAGE_SIZE];153 /* Allocate a new page */154 if (!cur_folio) {155 cur_folio = btrfs_alloc_compr_folio();156 if (!cur_folio)157 return -ENOMEM;158 out_folios[*cur_out / PAGE_SIZE] = cur_folio;159 }160 161 kaddr = kmap_local_folio(cur_folio, 0);162 write_compress_length(kaddr + offset_in_page(*cur_out),163 compressed_size);164 *cur_out += LZO_LEN;165 166 orig_out = *cur_out;167 168 /* Copy compressed data */169 while (*cur_out - orig_out < compressed_size) {170 u32 copy_len = min_t(u32, sectorsize - *cur_out % sectorsize,171 orig_out + compressed_size - *cur_out);172 173 kunmap_local(kaddr);174 175 if ((*cur_out / PAGE_SIZE) >= max_nr_folio)176 return -E2BIG;177 178 cur_folio = out_folios[*cur_out / PAGE_SIZE];179 /* Allocate a new page */180 if (!cur_folio) {181 cur_folio = btrfs_alloc_compr_folio();182 if (!cur_folio)183 return -ENOMEM;184 out_folios[*cur_out / PAGE_SIZE] = cur_folio;185 }186 kaddr = kmap_local_folio(cur_folio, 0);187 188 memcpy(kaddr + offset_in_page(*cur_out),189 compressed_data + *cur_out - orig_out, copy_len);190 191 *cur_out += copy_len;192 }193 194 /*195 * Check if we can fit the next segment header into the remaining space196 * of the sector.197 */198 sector_bytes_left = round_up(*cur_out, sectorsize) - *cur_out;199 if (sector_bytes_left >= LZO_LEN || sector_bytes_left == 0)200 goto out;201 202 /* The remaining size is not enough, pad it with zeros */203 memset(kaddr + offset_in_page(*cur_out), 0,204 sector_bytes_left);205 *cur_out += sector_bytes_left;206 207out:208 kunmap_local(kaddr);209 return 0;210}211 212int lzo_compress_folios(struct list_head *ws, struct address_space *mapping,213 u64 start, struct folio **folios, unsigned long *out_folios,214 unsigned long *total_in, unsigned long *total_out)215{216 struct workspace *workspace = list_entry(ws, struct workspace, list);217 const u32 sectorsize = inode_to_fs_info(mapping->host)->sectorsize;218 struct folio *folio_in = NULL;219 char *sizes_ptr;220 const unsigned long max_nr_folio = *out_folios;221 int ret = 0;222 /* Points to the file offset of input data */223 u64 cur_in = start;224 /* Points to the current output byte */225 u32 cur_out = 0;226 u32 len = *total_out;227 228 ASSERT(max_nr_folio > 0);229 *out_folios = 0;230 *total_out = 0;231 *total_in = 0;232 233 /*234 * Skip the header for now, we will later come back and write the total235 * compressed size236 */237 cur_out += LZO_LEN;238 while (cur_in < start + len) {239 char *data_in;240 const u32 sectorsize_mask = sectorsize - 1;241 u32 sector_off = (cur_in - start) & sectorsize_mask;242 u32 in_len;243 size_t out_len;244 245 /* Get the input page first */246 if (!folio_in) {247 ret = btrfs_compress_filemap_get_folio(mapping, cur_in, &folio_in);248 if (ret < 0)249 goto out;250 }251 252 /* Compress at most one sector of data each time */253 in_len = min_t(u32, start + len - cur_in, sectorsize - sector_off);254 ASSERT(in_len);255 data_in = kmap_local_folio(folio_in, 0);256 ret = lzo1x_1_compress(data_in +257 offset_in_page(cur_in), in_len,258 workspace->cbuf, &out_len,259 workspace->mem);260 kunmap_local(data_in);261 if (unlikely(ret < 0)) {262 /* lzo1x_1_compress never fails. */263 ret = -EIO;264 goto out;265 }266 267 ret = copy_compressed_data_to_page(workspace->cbuf, out_len,268 folios, max_nr_folio,269 &cur_out, sectorsize);270 if (ret < 0)271 goto out;272 273 cur_in += in_len;274 275 /*276 * Check if we're making it bigger after two sectors. And if277 * it is so, give up.278 */279 if (cur_in - start > sectorsize * 2 && cur_in - start < cur_out) {280 ret = -E2BIG;281 goto out;282 }283 284 /* Check if we have reached page boundary */285 if (PAGE_ALIGNED(cur_in)) {286 folio_put(folio_in);287 folio_in = NULL;288 }289 }290 291 /* Store the size of all chunks of compressed data */292 sizes_ptr = kmap_local_folio(folios[0], 0);293 write_compress_length(sizes_ptr, cur_out);294 kunmap_local(sizes_ptr);295 296 ret = 0;297 *total_out = cur_out;298 *total_in = cur_in - start;299out:300 if (folio_in)301 folio_put(folio_in);302 *out_folios = DIV_ROUND_UP(cur_out, PAGE_SIZE);303 return ret;304}305 306/*307 * Copy the compressed segment payload into @dest.308 *309 * For the payload there will be no padding, just need to do page switching.310 */311static void copy_compressed_segment(struct compressed_bio *cb,312 char *dest, u32 len, u32 *cur_in)313{314 u32 orig_in = *cur_in;315 316 while (*cur_in < orig_in + len) {317 struct folio *cur_folio;318 u32 copy_len = min_t(u32, PAGE_SIZE - offset_in_page(*cur_in),319 orig_in + len - *cur_in);320 321 ASSERT(copy_len);322 cur_folio = cb->compressed_folios[*cur_in / PAGE_SIZE];323 324 memcpy_from_folio(dest + *cur_in - orig_in, cur_folio,325 offset_in_folio(cur_folio, *cur_in), copy_len);326 327 *cur_in += copy_len;328 }329}330 331int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)332{333 struct workspace *workspace = list_entry(ws, struct workspace, list);334 const struct btrfs_fs_info *fs_info = cb->bbio.inode->root->fs_info;335 const u32 sectorsize = fs_info->sectorsize;336 char *kaddr;337 int ret;338 /* Compressed data length, can be unaligned */339 u32 len_in;340 /* Offset inside the compressed data */341 u32 cur_in = 0;342 /* Bytes decompressed so far */343 u32 cur_out = 0;344 345 kaddr = kmap_local_folio(cb->compressed_folios[0], 0);346 len_in = read_compress_length(kaddr);347 kunmap_local(kaddr);348 cur_in += LZO_LEN;349 350 /*351 * LZO header length check352 *353 * The total length should not exceed the maximum extent length,354 * and all sectors should be used.355 * If this happens, it means the compressed extent is corrupted.356 */357 if (unlikely(len_in > min_t(size_t, BTRFS_MAX_COMPRESSED, cb->compressed_len) ||358 round_up(len_in, sectorsize) < cb->compressed_len)) {359 struct btrfs_inode *inode = cb->bbio.inode;360 361 btrfs_err(fs_info,362"lzo header invalid, root %llu inode %llu offset %llu lzo len %u compressed len %u",363 btrfs_root_id(inode->root), btrfs_ino(inode),364 cb->start, len_in, cb->compressed_len);365 return -EUCLEAN;366 }367 368 /* Go through each lzo segment */369 while (cur_in < len_in) {370 struct folio *cur_folio;371 /* Length of the compressed segment */372 u32 seg_len;373 u32 sector_bytes_left;374 size_t out_len = lzo1x_worst_compress(sectorsize);375 376 /*377 * We should always have enough space for one segment header378 * inside current sector.379 */380 ASSERT(cur_in / sectorsize ==381 (cur_in + LZO_LEN - 1) / sectorsize);382 cur_folio = cb->compressed_folios[cur_in / PAGE_SIZE];383 ASSERT(cur_folio);384 kaddr = kmap_local_folio(cur_folio, 0);385 seg_len = read_compress_length(kaddr + offset_in_page(cur_in));386 kunmap_local(kaddr);387 cur_in += LZO_LEN;388 389 if (unlikely(seg_len > WORKSPACE_CBUF_LENGTH)) {390 struct btrfs_inode *inode = cb->bbio.inode;391 392 /*393 * seg_len shouldn't be larger than we have allocated394 * for workspace->cbuf395 */396 btrfs_err(fs_info,397 "lzo segment too big, root %llu inode %llu offset %llu len %u",398 btrfs_root_id(inode->root), btrfs_ino(inode),399 cb->start, seg_len);400 return -EIO;401 }402 403 /* Copy the compressed segment payload into workspace */404 copy_compressed_segment(cb, workspace->cbuf, seg_len, &cur_in);405 406 /* Decompress the data */407 ret = lzo1x_decompress_safe(workspace->cbuf, seg_len,408 workspace->buf, &out_len);409 if (unlikely(ret != LZO_E_OK)) {410 struct btrfs_inode *inode = cb->bbio.inode;411 412 btrfs_err(fs_info,413 "lzo decompression failed, error %d root %llu inode %llu offset %llu",414 ret, btrfs_root_id(inode->root), btrfs_ino(inode),415 cb->start);416 return -EIO;417 }418 419 /* Copy the data into inode pages */420 ret = btrfs_decompress_buf2page(workspace->buf, out_len, cb, cur_out);421 cur_out += out_len;422 423 /* All data read, exit */424 if (ret == 0)425 return 0;426 ret = 0;427 428 /* Check if the sector has enough space for a segment header */429 sector_bytes_left = sectorsize - (cur_in % sectorsize);430 if (sector_bytes_left >= LZO_LEN)431 continue;432 433 /* Skip the padding zeros */434 cur_in += sector_bytes_left;435 }436 437 return 0;438}439 440int lzo_decompress(struct list_head *ws, const u8 *data_in,441 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,442 size_t destlen)443{444 struct workspace *workspace = list_entry(ws, struct workspace, list);445 struct btrfs_fs_info *fs_info = folio_to_fs_info(dest_folio);446 const u32 sectorsize = fs_info->sectorsize;447 size_t in_len;448 size_t out_len;449 size_t max_segment_len = WORKSPACE_BUF_LENGTH;450 int ret = 0;451 452 if (srclen < LZO_LEN || srclen > max_segment_len + LZO_LEN * 2)453 return -EUCLEAN;454 455 in_len = read_compress_length(data_in);456 if (in_len != srclen)457 return -EUCLEAN;458 data_in += LZO_LEN;459 460 in_len = read_compress_length(data_in);461 if (in_len != srclen - LZO_LEN * 2) {462 ret = -EUCLEAN;463 goto out;464 }465 data_in += LZO_LEN;466 467 out_len = sectorsize;468 ret = lzo1x_decompress_safe(data_in, in_len, workspace->buf, &out_len);469 if (unlikely(ret != LZO_E_OK)) {470 struct btrfs_inode *inode = folio_to_inode(dest_folio);471 472 btrfs_err(fs_info,473 "lzo decompression failed, error %d root %llu inode %llu offset %llu",474 ret, btrfs_root_id(inode->root), btrfs_ino(inode),475 folio_pos(dest_folio));476 ret = -EIO;477 goto out;478 }479 480 ASSERT(out_len <= sectorsize);481 memcpy_to_folio(dest_folio, dest_pgoff, workspace->buf, out_len);482 /* Early end, considered as an error. */483 if (unlikely(out_len < destlen)) {484 ret = -EIO;485 folio_zero_range(dest_folio, dest_pgoff + out_len, destlen - out_len);486 }487out:488 return ret;489}490 491const struct btrfs_compress_op btrfs_lzo_compress = {492 .workspace_manager = &wsm,493 .max_level = 1,494 .default_level = 1,495};496