Linux/fs/squashfs/block.c

Version: ~ [ linux-6.12-rc7 ] ~ [ linux-6.11.7 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.60 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.116 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.171 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.229 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.285 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.323 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.12 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

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1 // SPDX-License-Identifier: GPL-2.0-or-later << 2 /* 1 /* 3 * Squashfs - a compressed read only filesyste 2 * Squashfs - a compressed read only filesystem for Linux 4 * 3 * 5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 6 * Phillip Lougher <phillip@squashfs.org.uk> 5 * Phillip Lougher <phillip@squashfs.org.uk> 7 * 6 * >> 7 * This program is free software; you can redistribute it and/or >> 8 * modify it under the terms of the GNU General Public License >> 9 * as published by the Free Software Foundation; either version 2, >> 10 * or (at your option) any later version. >> 11 * >> 12 * This program is distributed in the hope that it will be useful, >> 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of >> 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> 15 * GNU General Public License for more details. >> 16 * >> 17 * You should have received a copy of the GNU General Public License >> 18 * along with this program; if not, write to the Free Software >> 19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. >> 20 * 8 * block.c 21 * block.c 9 */ 22 */ 10 23 11 /* 24 /* 12 * This file implements the low-level routines 25 * This file implements the low-level routines to read and decompress 13 * datablocks and metadata blocks. 26 * datablocks and metadata blocks. 14 */ 27 */ 15 28 16 #include <linux/blkdev.h> << 17 #include <linux/fs.h> 29 #include <linux/fs.h> 18 #include <linux/vfs.h> 30 #include <linux/vfs.h> 19 #include <linux/slab.h> 31 #include <linux/slab.h> 20 #include <linux/pagemap.h> << 21 #include <linux/string.h> 32 #include <linux/string.h> >> 33 #include <linux/buffer_head.h> 22 #include <linux/bio.h> 34 #include <linux/bio.h> 23 35 24 #include "squashfs_fs.h" 36 #include "squashfs_fs.h" 25 #include "squashfs_fs_sb.h" 37 #include "squashfs_fs_sb.h" 26 #include "squashfs.h" 38 #include "squashfs.h" 27 #include "decompressor.h" 39 #include "decompressor.h" 28 #include "page_actor.h" 40 #include "page_actor.h" 29 41 30 /* 42 /* 31 * Returns the amount of bytes copied to the p !! 43 * Read the metadata block length, this is stored in the first two >> 44 * bytes of the metadata block. 32 */ 45 */ 33 static int copy_bio_to_actor(struct bio *bio, !! 46 static struct buffer_head *get_block_length(struct super_block *sb, 34 struct squashfs_p !! 47 u64 *cur_index, int *offset, int *length) 35 int offset, int r << 36 { << 37 void *actor_addr; << 38 struct bvec_iter_all iter_all = {}; << 39 struct bio_vec *bvec = bvec_init_iter_ << 40 int copied_bytes = 0; << 41 int actor_offset = 0; << 42 << 43 squashfs_actor_nobuff(actor); << 44 actor_addr = squashfs_first_page(actor << 45 << 46 if (WARN_ON_ONCE(!bio_next_segment(bio << 47 return 0; << 48 << 49 while (copied_bytes < req_length) { << 50 int bytes_to_copy = min_t(int, << 51 PAGE << 52 << 53 bytes_to_copy = min_t(int, byt << 54 req_leng << 55 if (!IS_ERR(actor_addr)) << 56 memcpy(actor_addr + ac << 57 offset << 58 << 59 actor_offset += bytes_to_copy; << 60 copied_bytes += bytes_to_copy; << 61 offset += bytes_to_copy; << 62 << 63 if (actor_offset >= PAGE_SIZE) << 64 actor_addr = squashfs_ << 65 if (!actor_addr) << 66 break; << 67 actor_offset = 0; << 68 } << 69 if (offset >= bvec->bv_len) { << 70 if (!bio_next_segment( << 71 break; << 72 offset = 0; << 73 } << 74 } << 75 squashfs_finish_page(actor); << 76 return copied_bytes; << 77 } << 78 << 79 static int squashfs_bio_read_cached(struct bio << 80 struct address_space *cache_ma << 81 u64 read_start, u64 read_end, << 82 { 48 { 83 struct page *head_to_cache = NULL, *ta !! 49 struct squashfs_sb_info *msblk = sb->s_fs_info; 84 struct block_device *bdev = fullbio->b !! 50 struct buffer_head *bh; 85 int start_idx = 0, end_idx = 0; << 86 struct bvec_iter_all iter_all; << 87 struct bio *bio = NULL; << 88 struct bio_vec *bv; << 89 int idx = 0; << 90 int err = 0; << 91 << 92 bio_for_each_segment_all(bv, fullbio, << 93 struct page *page = bv->bv_pag << 94 << 95 if (page->mapping == cache_map << 96 idx++; << 97 continue; << 98 } << 99 << 100 /* << 101 * We only use this when the d << 102 * the page size, so read_star << 103 * << 104 * Compare these to the origin << 105 * only cache pages which were << 106 * are the ones which are like << 107 * adjacent blocks. << 108 */ << 109 if (idx == 0 && index != read_ << 110 head_to_cache = page; << 111 else if (idx == page_count - 1 << 112 tail_to_cache = page; << 113 << 114 if (!bio || idx != end_idx) { << 115 struct bio *new = bio_ << 116 << 117 << 118 if (bio) { << 119 bio_trim(bio, << 120 (end_ << 121 bio_chain(bio, << 122 submit_bio(bio << 123 } << 124 << 125 bio = new; << 126 start_idx = idx; << 127 } << 128 << 129 idx++; << 130 end_idx = idx; << 131 } << 132 << 133 if (bio) { << 134 bio_trim(bio, start_idx * PAGE << 135 (end_idx - start_idx) << 136 err = submit_bio_wait(bio); << 137 bio_put(bio); << 138 } << 139 << 140 if (err) << 141 return err; << 142 << 143 if (head_to_cache) { << 144 int ret = add_to_page_cache_lr << 145 << 146 << 147 << 148 if (!ret) { << 149 SetPageUptodate(head_t << 150 unlock_page(head_to_ca << 151 } << 152 << 153 } << 154 << 155 if (tail_to_cache) { << 156 int ret = add_to_page_cache_lr << 157 << 158 << 159 << 160 if (!ret) { << 161 SetPageUptodate(tail_t << 162 unlock_page(tail_to_ca << 163 } << 164 } << 165 << 166 return 0; << 167 } << 168 << 169 static struct page *squashfs_get_cache_page(st << 170 pg << 171 { << 172 struct page *page; << 173 << 174 if (!mapping) << 175 return NULL; << 176 << 177 page = find_get_page(mapping, index); << 178 if (!page) << 179 return NULL; << 180 51 181 if (!PageUptodate(page)) { !! 52 bh = sb_bread(sb, *cur_index); 182 put_page(page); !! 53 if (bh == NULL) 183 return NULL; 54 return NULL; 184 } << 185 << 186 return page; << 187 } << 188 << 189 static int squashfs_bio_read(struct super_bloc << 190 struct bio **biop << 191 { << 192 struct squashfs_sb_info *msblk = sb->s << 193 struct address_space *cache_mapping = << 194 const u64 read_start = round_down(inde << 195 const sector_t block = read_start >> m << 196 const u64 read_end = round_up(index + << 197 const sector_t block_end = read_end >> << 198 int offset = read_start - round_down(i << 199 int total_len = (block_end - block) << << 200 const int page_count = DIV_ROUND_UP(to << 201 int error, i; << 202 struct bio *bio; << 203 55 204 bio = bio_kmalloc(page_count, GFP_NOIO !! 56 if (msblk->devblksize - *offset == 1) { 205 if (!bio) !! 57 *length = (unsigned char) bh->b_data[*offset]; 206 return -ENOMEM; !! 58 put_bh(bh); 207 bio_init(bio, sb->s_bdev, bio->bi_inli !! 59 bh = sb_bread(sb, ++(*cur_index)); 208 bio->bi_iter.bi_sector = block * (msbl !! 60 if (bh == NULL) >> 61 return NULL; >> 62 *length |= (unsigned char) bh->b_data[0] << 8; >> 63 *offset = 1; >> 64 } else { >> 65 *length = (unsigned char) bh->b_data[*offset] | >> 66 (unsigned char) bh->b_data[*offset + 1] << 8; >> 67 *offset += 2; 209 68 210 for (i = 0; i < page_count; ++i) { !! 69 if (*offset == msblk->devblksize) { 211 unsigned int len = !! 70 put_bh(bh); 212 min_t(unsigned int, PA !! 71 bh = sb_bread(sb, ++(*cur_index)); 213 pgoff_t index = (read_start >> !! 72 if (bh == NULL) 214 struct page *page; !! 73 return NULL; 215 !! 74 *offset = 0; 216 page = squashfs_get_cache_page << 217 if (!page) << 218 page = alloc_page(GFP_ << 219 << 220 if (!page) { << 221 error = -ENOMEM; << 222 goto out_free_bio; << 223 } 75 } 224 << 225 /* << 226 * Use the __ version to avoid << 227 * to be separate when we chec << 228 */ << 229 __bio_add_page(bio, page, len, << 230 offset = 0; << 231 total_len -= len; << 232 } 76 } 233 77 234 if (cache_mapping) !! 78 return bh; 235 error = squashfs_bio_read_cach << 236 << 237 << 238 else << 239 error = submit_bio_wait(bio); << 240 if (error) << 241 goto out_free_bio; << 242 << 243 *biop = bio; << 244 *block_offset = index & ((1 << msblk-> << 245 return 0; << 246 << 247 out_free_bio: << 248 bio_free_pages(bio); << 249 bio_uninit(bio); << 250 kfree(bio); << 251 return error; << 252 } 79 } 253 80 >> 81 254 /* 82 /* 255 * Read and decompress a metadata block or dat 83 * Read and decompress a metadata block or datablock. Length is non-zero 256 * if a datablock is being read (the size is s 84 * if a datablock is being read (the size is stored elsewhere in the 257 * filesystem), otherwise the length is obtain 85 * filesystem), otherwise the length is obtained from the first two bytes of 258 * the metadata block. A bit in the length fi 86 * the metadata block. A bit in the length field indicates if the block 259 * is stored uncompressed in the filesystem (u 87 * is stored uncompressed in the filesystem (usually because compression 260 * generated a larger block - this does occasi 88 * generated a larger block - this does occasionally happen with compression 261 * algorithms). 89 * algorithms). 262 */ 90 */ 263 int squashfs_read_data(struct super_block *sb, 91 int squashfs_read_data(struct super_block *sb, u64 index, int length, 264 u64 *next_index, struct !! 92 u64 *next_index, struct squashfs_page_actor *output) 265 { 93 { 266 struct squashfs_sb_info *msblk = sb->s 94 struct squashfs_sb_info *msblk = sb->s_fs_info; 267 struct bio *bio = NULL; !! 95 struct buffer_head **bh; 268 int compressed; !! 96 int offset = index & ((1 << msblk->devblksize_log2) - 1); 269 int res; !! 97 u64 cur_index = index >> msblk->devblksize_log2; 270 int offset; !! 98 int bytes, compressed, b = 0, k = 0, avail, i; >> 99 >> 100 bh = kcalloc(((output->length + msblk->devblksize - 1) >> 101 >> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL); >> 102 if (bh == NULL) >> 103 return -ENOMEM; 271 104 272 if (length) { 105 if (length) { 273 /* 106 /* 274 * Datablock. 107 * Datablock. 275 */ 108 */ >> 109 bytes = -offset; 276 compressed = SQUASHFS_COMPRESS 110 compressed = SQUASHFS_COMPRESSED_BLOCK(length); 277 length = SQUASHFS_COMPRESSED_S 111 length = SQUASHFS_COMPRESSED_SIZE_BLOCK(length); >> 112 if (next_index) >> 113 *next_index = index + length; >> 114 278 TRACE("Block @ 0x%llx, %scompr 115 TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n", 279 index, compressed ? "" 116 index, compressed ? "" : "un", length, output->length); >> 117 >> 118 if (length < 0 || length > output->length || >> 119 (index + length) > msblk->bytes_used) >> 120 goto read_failure; >> 121 >> 122 for (b = 0; bytes < length; b++, cur_index++) { >> 123 bh[b] = sb_getblk(sb, cur_index); >> 124 if (bh[b] == NULL) >> 125 goto block_release; >> 126 bytes += msblk->devblksize; >> 127 } >> 128 ll_rw_block(REQ_OP_READ, 0, b, bh); 280 } else { 129 } else { 281 /* 130 /* 282 * Metadata block. 131 * Metadata block. 283 */ 132 */ 284 const u8 *data; !! 133 if ((index + 2) > msblk->bytes_used) 285 struct bvec_iter_all iter_all !! 134 goto read_failure; 286 struct bio_vec *bvec = bvec_in !! 135 287 !! 136 bh[0] = get_block_length(sb, &cur_index, &offset, &length); 288 if (index + 2 > msblk->bytes_u !! 137 if (bh[0] == NULL) 289 res = -EIO; !! 138 goto read_failure; 290 goto out; !! 139 b = 1; 291 } << 292 res = squashfs_bio_read(sb, in << 293 if (res) << 294 goto out; << 295 << 296 if (WARN_ON_ONCE(!bio_next_seg << 297 res = -EIO; << 298 goto out_free_bio; << 299 } << 300 /* Extract the length of the m << 301 data = bvec_virt(bvec); << 302 length = data[offset]; << 303 if (offset < bvec->bv_len - 1) << 304 length |= data[offset << 305 } else { << 306 if (WARN_ON_ONCE(!bio_ << 307 res = -EIO; << 308 goto out_free_ << 309 } << 310 data = bvec_virt(bvec) << 311 length |= data[0] << 8 << 312 } << 313 bio_free_pages(bio); << 314 bio_uninit(bio); << 315 kfree(bio); << 316 140 >> 141 bytes = msblk->devblksize - offset; 317 compressed = SQUASHFS_COMPRESS 142 compressed = SQUASHFS_COMPRESSED(length); 318 length = SQUASHFS_COMPRESSED_S 143 length = SQUASHFS_COMPRESSED_SIZE(length); 319 index += 2; !! 144 if (next_index) >> 145 *next_index = index + length + 2; 320 146 321 TRACE("Block @ 0x%llx, %scompr !! 147 TRACE("Block @ 0x%llx, %scompressed size %d\n", index, 322 compressed ? "" : "un", !! 148 compressed ? "" : "un", length); 323 } << 324 if (length <= 0 || length > output->le << 325 (index + length) > msb << 326 res = -EIO; << 327 goto out; << 328 } << 329 149 330 if (next_index) !! 150 if (length < 0 || length > output->length || 331 *next_index = index + length; !! 151 (index + length) > msblk->bytes_used) >> 152 goto block_release; 332 153 333 res = squashfs_bio_read(sb, index, len !! 154 for (; bytes < length; b++) { 334 if (res) !! 155 bh[b] = sb_getblk(sb, ++cur_index); 335 goto out; !! 156 if (bh[b] == NULL) >> 157 goto block_release; >> 158 bytes += msblk->devblksize; >> 159 } >> 160 ll_rw_block(REQ_OP_READ, 0, b - 1, bh + 1); >> 161 } >> 162 >> 163 for (i = 0; i < b; i++) { >> 164 wait_on_buffer(bh[i]); >> 165 if (!buffer_uptodate(bh[i])) >> 166 goto block_release; >> 167 } 336 168 337 if (compressed) { 169 if (compressed) { 338 if (!msblk->stream) { !! 170 if (!msblk->stream) 339 res = -EIO; !! 171 goto read_failure; 340 goto out_free_bio; !! 172 length = squashfs_decompress(msblk, bh, b, offset, length, 341 } !! 173 output); 342 res = msblk->thread_ops->decom !! 174 if (length < 0) >> 175 goto read_failure; 343 } else { 176 } else { 344 res = copy_bio_to_actor(bio, o !! 177 /* 345 } !! 178 * Block is uncompressed. >> 179 */ >> 180 int in, pg_offset = 0; >> 181 void *data = squashfs_first_page(output); 346 182 347 out_free_bio: !! 183 for (bytes = length; k < b; k++) { 348 bio_free_pages(bio); !! 184 in = min(bytes, msblk->devblksize - offset); 349 bio_uninit(bio); !! 185 bytes -= in; 350 kfree(bio); !! 186 while (in) { 351 out: !! 187 if (pg_offset == PAGE_SIZE) { 352 if (res < 0) { !! 188 data = squashfs_next_page(output); 353 ERROR("Failed to read block 0x !! 189 pg_offset = 0; 354 if (msblk->panic_on_errors) !! 190 } 355 panic("squashfs read f !! 191 avail = min_t(int, in, PAGE_SIZE - >> 192 pg_offset); >> 193 memcpy(data + pg_offset, bh[k]->b_data + offset, >> 194 avail); >> 195 in -= avail; >> 196 pg_offset += avail; >> 197 offset += avail; >> 198 } >> 199 offset = 0; >> 200 put_bh(bh[k]); >> 201 } >> 202 squashfs_finish_page(output); 356 } 203 } 357 204 358 return res; !! 205 kfree(bh); >> 206 return length; >> 207 >> 208 block_release: >> 209 for (; k < b; k++) >> 210 put_bh(bh[k]); >> 211 >> 212 read_failure: >> 213 ERROR("squashfs_read_data failed to read block 0x%llx\n", >> 214 (unsigned long long) index); >> 215 kfree(bh); >> 216 return -EIO; 359 } 217 } 360 218

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TOMOYO Linux Cross Reference
Linux/fs/squashfs/block.c

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Differences between /fs/squashfs/block.c (Version linux-6.12-rc7) and /fs/squashfs/block.c (Version linux-4.19.323)

TOMOYO Linux Cross Reference Linux/fs/squashfs/block.c

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Differences between /fs/squashfs/block.c (Version linux-6.12-rc7) and /fs/squashfs/block.c (Version linux-4.19.323)

TOMOYO Linux Cross Reference
Linux/fs/squashfs/block.c