1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2017-2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Copyright (C) 2021, Alibaba Cloud 6 */ 7 #include "internal.h" 8 #include <linux/sched/mm.h> 9 #include <trace/events/erofs.h> 10 11 void erofs_unmap_metabuf(struct erofs_buf *buf) 12 { 13 if (!buf->base) 14 return; 15 kunmap_local(buf->base); 16 buf->base = NULL; 17 } 18 19 void erofs_put_metabuf(struct erofs_buf *buf) 20 { 21 if (!buf->page) 22 return; 23 erofs_unmap_metabuf(buf); 24 folio_put(page_folio(buf->page)); 25 buf->page = NULL; 26 } 27 28 void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset, 29 enum erofs_kmap_type type) 30 { 31 pgoff_t index = offset >> PAGE_SHIFT; 32 struct folio *folio = NULL; 33 34 if (buf->page) { 35 folio = page_folio(buf->page); 36 if (folio_file_page(folio, index) != buf->page) 37 erofs_unmap_metabuf(buf); 38 } 39 if (!folio || !folio_contains(folio, index)) { 40 erofs_put_metabuf(buf); 41 folio = read_mapping_folio(buf->mapping, index, buf->file); 42 if (IS_ERR(folio)) 43 return folio; 44 } 45 buf->page = folio_file_page(folio, index); 46 if (!buf->base && type == EROFS_KMAP) 47 buf->base = kmap_local_page(buf->page); 48 if (type == EROFS_NO_KMAP) 49 return NULL; 50 return buf->base + (offset & ~PAGE_MASK); 51 } 52 53 void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb) 54 { 55 struct erofs_sb_info *sbi = EROFS_SB(sb); 56 57 buf->file = NULL; 58 if (erofs_is_fileio_mode(sbi)) { 59 buf->file = sbi->fdev; /* some fs like FUSE needs it */ 60 buf->mapping = buf->file->f_mapping; 61 } else if (erofs_is_fscache_mode(sb)) 62 buf->mapping = sbi->s_fscache->inode->i_mapping; 63 else 64 buf->mapping = sb->s_bdev->bd_mapping; 65 } 66 67 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 68 erofs_off_t offset, enum erofs_kmap_type type) 69 { 70 erofs_init_metabuf(buf, sb); 71 return erofs_bread(buf, offset, type); 72 } 73 74 static int erofs_map_blocks_flatmode(struct inode *inode, 75 struct erofs_map_blocks *map) 76 { 77 struct erofs_inode *vi = EROFS_I(inode); 78 struct super_block *sb = inode->i_sb; 79 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 80 erofs_blk_t lastblk = erofs_iblks(inode) - tailendpacking; 81 82 map->m_flags = EROFS_MAP_MAPPED; /* no hole in flat inodes */ 83 if (map->m_la < erofs_pos(sb, lastblk)) { 84 map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la; 85 map->m_plen = erofs_pos(sb, lastblk) - map->m_la; 86 } else { 87 DBG_BUGON(!tailendpacking); 88 map->m_pa = erofs_iloc(inode) + vi->inode_isize + 89 vi->xattr_isize + erofs_blkoff(sb, map->m_la); 90 map->m_plen = inode->i_size - map->m_la; 91 92 /* inline data should be located in the same meta block */ 93 if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { 94 erofs_err(sb, "inline data across blocks @ nid %llu", vi->nid); 95 DBG_BUGON(1); 96 return -EFSCORRUPTED; 97 } 98 map->m_flags |= EROFS_MAP_META; 99 } 100 return 0; 101 } 102 103 int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) 104 { 105 struct super_block *sb = inode->i_sb; 106 struct erofs_inode *vi = EROFS_I(inode); 107 struct erofs_inode_chunk_index *idx; 108 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 109 u64 chunknr; 110 unsigned int unit; 111 erofs_off_t pos; 112 void *kaddr; 113 int err = 0; 114 115 trace_erofs_map_blocks_enter(inode, map, 0); 116 map->m_deviceid = 0; 117 if (map->m_la >= inode->i_size) { 118 /* leave out-of-bound access unmapped */ 119 map->m_flags = 0; 120 map->m_plen = map->m_llen; 121 goto out; 122 } 123 124 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 125 err = erofs_map_blocks_flatmode(inode, map); 126 goto out; 127 } 128 129 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 130 unit = sizeof(*idx); /* chunk index */ 131 else 132 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 133 134 chunknr = map->m_la >> vi->chunkbits; 135 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + 136 vi->xattr_isize, unit) + unit * chunknr; 137 138 kaddr = erofs_read_metabuf(&buf, sb, pos, EROFS_KMAP); 139 if (IS_ERR(kaddr)) { 140 err = PTR_ERR(kaddr); 141 goto out; 142 } 143 map->m_la = chunknr << vi->chunkbits; 144 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 145 round_up(inode->i_size - map->m_la, sb->s_blocksize)); 146 147 /* handle block map */ 148 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 149 __le32 *blkaddr = kaddr; 150 151 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 152 map->m_flags = 0; 153 } else { 154 map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr)); 155 map->m_flags = EROFS_MAP_MAPPED; 156 } 157 goto out_unlock; 158 } 159 /* parse chunk indexes */ 160 idx = kaddr; 161 switch (le32_to_cpu(idx->blkaddr)) { 162 case EROFS_NULL_ADDR: 163 map->m_flags = 0; 164 break; 165 default: 166 map->m_deviceid = le16_to_cpu(idx->device_id) & 167 EROFS_SB(sb)->device_id_mask; 168 map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr)); 169 map->m_flags = EROFS_MAP_MAPPED; 170 break; 171 } 172 out_unlock: 173 erofs_put_metabuf(&buf); 174 out: 175 if (!err) 176 map->m_llen = map->m_plen; 177 trace_erofs_map_blocks_exit(inode, map, 0, err); 178 return err; 179 } 180 181 static void erofs_fill_from_devinfo(struct erofs_map_dev *map, 182 struct erofs_device_info *dif) 183 { 184 map->m_bdev = NULL; 185 map->m_fp = NULL; 186 if (dif->file) { 187 if (S_ISBLK(file_inode(dif->file)->i_mode)) 188 map->m_bdev = file_bdev(dif->file); 189 else 190 map->m_fp = dif->file; 191 } 192 map->m_daxdev = dif->dax_dev; 193 map->m_dax_part_off = dif->dax_part_off; 194 map->m_fscache = dif->fscache; 195 } 196 197 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 198 { 199 struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 200 struct erofs_device_info *dif; 201 erofs_off_t startoff, length; 202 int id; 203 204 map->m_bdev = sb->s_bdev; 205 map->m_daxdev = EROFS_SB(sb)->dax_dev; 206 map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; 207 map->m_fscache = EROFS_SB(sb)->s_fscache; 208 map->m_fp = EROFS_SB(sb)->fdev; 209 210 if (map->m_deviceid) { 211 down_read(&devs->rwsem); 212 dif = idr_find(&devs->tree, map->m_deviceid - 1); 213 if (!dif) { 214 up_read(&devs->rwsem); 215 return -ENODEV; 216 } 217 if (devs->flatdev) { 218 map->m_pa += erofs_pos(sb, dif->mapped_blkaddr); 219 up_read(&devs->rwsem); 220 return 0; 221 } 222 erofs_fill_from_devinfo(map, dif); 223 up_read(&devs->rwsem); 224 } else if (devs->extra_devices && !devs->flatdev) { 225 down_read(&devs->rwsem); 226 idr_for_each_entry(&devs->tree, dif, id) { 227 if (!dif->mapped_blkaddr) 228 continue; 229 230 startoff = erofs_pos(sb, dif->mapped_blkaddr); 231 length = erofs_pos(sb, dif->blocks); 232 if (map->m_pa >= startoff && 233 map->m_pa < startoff + length) { 234 map->m_pa -= startoff; 235 erofs_fill_from_devinfo(map, dif); 236 break; 237 } 238 } 239 up_read(&devs->rwsem); 240 } 241 return 0; 242 } 243 244 /* 245 * bit 30: I/O error occurred on this folio 246 * bit 0 - 29: remaining parts to complete this folio 247 */ 248 #define EROFS_ONLINEFOLIO_EIO (1 << 30) 249 250 void erofs_onlinefolio_init(struct folio *folio) 251 { 252 union { 253 atomic_t o; 254 void *v; 255 } u = { .o = ATOMIC_INIT(1) }; 256 257 folio->private = u.v; /* valid only if file-backed folio is locked */ 258 } 259 260 void erofs_onlinefolio_split(struct folio *folio) 261 { 262 atomic_inc((atomic_t *)&folio->private); 263 } 264 265 void erofs_onlinefolio_end(struct folio *folio, int err) 266 { 267 int orig, v; 268 269 do { 270 orig = atomic_read((atomic_t *)&folio->private); 271 v = (orig - 1) | (err ? EROFS_ONLINEFOLIO_EIO : 0); 272 } while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig); 273 274 if (v & ~EROFS_ONLINEFOLIO_EIO) 275 return; 276 folio->private = 0; 277 folio_end_read(folio, !(v & EROFS_ONLINEFOLIO_EIO)); 278 } 279 280 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 281 unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 282 { 283 int ret; 284 struct super_block *sb = inode->i_sb; 285 struct erofs_map_blocks map; 286 struct erofs_map_dev mdev; 287 288 map.m_la = offset; 289 map.m_llen = length; 290 291 ret = erofs_map_blocks(inode, &map); 292 if (ret < 0) 293 return ret; 294 295 mdev = (struct erofs_map_dev) { 296 .m_deviceid = map.m_deviceid, 297 .m_pa = map.m_pa, 298 }; 299 ret = erofs_map_dev(sb, &mdev); 300 if (ret) 301 return ret; 302 303 iomap->offset = map.m_la; 304 if (flags & IOMAP_DAX) 305 iomap->dax_dev = mdev.m_daxdev; 306 else 307 iomap->bdev = mdev.m_bdev; 308 iomap->length = map.m_llen; 309 iomap->flags = 0; 310 iomap->private = NULL; 311 312 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 313 iomap->type = IOMAP_HOLE; 314 iomap->addr = IOMAP_NULL_ADDR; 315 if (!iomap->length) 316 iomap->length = length; 317 return 0; 318 } 319 320 if (map.m_flags & EROFS_MAP_META) { 321 void *ptr; 322 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 323 324 iomap->type = IOMAP_INLINE; 325 ptr = erofs_read_metabuf(&buf, sb, mdev.m_pa, EROFS_KMAP); 326 if (IS_ERR(ptr)) 327 return PTR_ERR(ptr); 328 iomap->inline_data = ptr; 329 iomap->private = buf.base; 330 } else { 331 iomap->type = IOMAP_MAPPED; 332 iomap->addr = mdev.m_pa; 333 if (flags & IOMAP_DAX) 334 iomap->addr += mdev.m_dax_part_off; 335 } 336 return 0; 337 } 338 339 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 340 ssize_t written, unsigned int flags, struct iomap *iomap) 341 { 342 void *ptr = iomap->private; 343 344 if (ptr) { 345 struct erofs_buf buf = { 346 .page = kmap_to_page(ptr), 347 .base = ptr, 348 }; 349 350 DBG_BUGON(iomap->type != IOMAP_INLINE); 351 erofs_put_metabuf(&buf); 352 } else { 353 DBG_BUGON(iomap->type == IOMAP_INLINE); 354 } 355 return written; 356 } 357 358 static const struct iomap_ops erofs_iomap_ops = { 359 .iomap_begin = erofs_iomap_begin, 360 .iomap_end = erofs_iomap_end, 361 }; 362 363 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 364 u64 start, u64 len) 365 { 366 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 367 #ifdef CONFIG_EROFS_FS_ZIP 368 return iomap_fiemap(inode, fieinfo, start, len, 369 &z_erofs_iomap_report_ops); 370 #else 371 return -EOPNOTSUPP; 372 #endif 373 } 374 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 375 } 376 377 /* 378 * since we dont have write or truncate flows, so no inode 379 * locking needs to be held at the moment. 380 */ 381 static int erofs_read_folio(struct file *file, struct folio *folio) 382 { 383 return iomap_read_folio(folio, &erofs_iomap_ops); 384 } 385 386 static void erofs_readahead(struct readahead_control *rac) 387 { 388 return iomap_readahead(rac, &erofs_iomap_ops); 389 } 390 391 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 392 { 393 return iomap_bmap(mapping, block, &erofs_iomap_ops); 394 } 395 396 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 397 { 398 struct inode *inode = file_inode(iocb->ki_filp); 399 400 /* no need taking (shared) inode lock since it's a ro filesystem */ 401 if (!iov_iter_count(to)) 402 return 0; 403 404 #ifdef CONFIG_FS_DAX 405 if (IS_DAX(inode)) 406 return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 407 #endif 408 if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_sb->s_bdev) 409 return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 410 NULL, 0, NULL, 0); 411 return filemap_read(iocb, to, 0); 412 } 413 414 /* for uncompressed (aligned) files and raw access for other files */ 415 const struct address_space_operations erofs_aops = { 416 .read_folio = erofs_read_folio, 417 .readahead = erofs_readahead, 418 .bmap = erofs_bmap, 419 .direct_IO = noop_direct_IO, 420 .release_folio = iomap_release_folio, 421 .invalidate_folio = iomap_invalidate_folio, 422 }; 423 424 #ifdef CONFIG_FS_DAX 425 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 426 unsigned int order) 427 { 428 return dax_iomap_fault(vmf, order, NULL, NULL, &erofs_iomap_ops); 429 } 430 431 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 432 { 433 return erofs_dax_huge_fault(vmf, 0); 434 } 435 436 static const struct vm_operations_struct erofs_dax_vm_ops = { 437 .fault = erofs_dax_fault, 438 .huge_fault = erofs_dax_huge_fault, 439 }; 440 441 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 442 { 443 if (!IS_DAX(file_inode(file))) 444 return generic_file_readonly_mmap(file, vma); 445 446 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 447 return -EINVAL; 448 449 vma->vm_ops = &erofs_dax_vm_ops; 450 vm_flags_set(vma, VM_HUGEPAGE); 451 return 0; 452 } 453 #else 454 #define erofs_file_mmap generic_file_readonly_mmap 455 #endif 456 457 static loff_t erofs_file_llseek(struct file *file, loff_t offset, int whence) 458 { 459 struct inode *inode = file->f_mapping->host; 460 const struct iomap_ops *ops = &erofs_iomap_ops; 461 462 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) 463 #ifdef CONFIG_EROFS_FS_ZIP 464 ops = &z_erofs_iomap_report_ops; 465 #else 466 return generic_file_llseek(file, offset, whence); 467 #endif 468 469 if (whence == SEEK_HOLE) 470 offset = iomap_seek_hole(inode, offset, ops); 471 else if (whence == SEEK_DATA) 472 offset = iomap_seek_data(inode, offset, ops); 473 else 474 return generic_file_llseek(file, offset, whence); 475 476 if (offset < 0) 477 return offset; 478 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes); 479 } 480 481 const struct file_operations erofs_file_fops = { 482 .llseek = erofs_file_llseek, 483 .read_iter = erofs_file_read_iter, 484 .mmap = erofs_file_mmap, 485 .get_unmapped_area = thp_get_unmapped_area, 486 .splice_read = filemap_splice_read, 487 }; 488