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->kmap_type == EROFS_KMAP) 14 kunmap_local(buf->base); 15 buf->base = NULL; 16 buf->kmap_type = EROFS_NO_KMAP; 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, NULL); 42 if (IS_ERR(folio)) 43 return folio; 44 } 45 buf->page = folio_file_page(folio, index); 46 47 if (buf->kmap_type == EROFS_NO_KMAP) { 48 if (type == EROFS_KMAP) 49 buf->base = kmap_local_page(buf->page); 50 buf->kmap_type = type; 51 } else if (buf->kmap_type != type) { 52 DBG_BUGON(1); 53 return ERR_PTR(-EFAULT); 54 } 55 if (type == EROFS_NO_KMAP) 56 return NULL; 57 return buf->base + (offset & ~PAGE_MASK); 58 } 59 60 void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb) 61 { 62 if (erofs_is_fscache_mode(sb)) 63 buf->mapping = EROFS_SB(sb)->s_fscache->inode->i_mapping; 64 else 65 buf->mapping = sb->s_bdev->bd_mapping; 66 } 67 68 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 69 erofs_off_t offset, enum erofs_kmap_type type) 70 { 71 erofs_init_metabuf(buf, sb); 72 return erofs_bread(buf, offset, type); 73 } 74 75 static int erofs_map_blocks_flatmode(struct inode *inode, 76 struct erofs_map_blocks *map) 77 { 78 erofs_blk_t nblocks, lastblk; 79 u64 offset = map->m_la; 80 struct erofs_inode *vi = EROFS_I(inode); 81 struct super_block *sb = inode->i_sb; 82 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 83 84 nblocks = erofs_iblks(inode); 85 lastblk = nblocks - tailendpacking; 86 87 /* there is no hole in flatmode */ 88 map->m_flags = EROFS_MAP_MAPPED; 89 if (offset < erofs_pos(sb, lastblk)) { 90 map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la; 91 map->m_plen = erofs_pos(sb, lastblk) - offset; 92 } else if (tailendpacking) { 93 map->m_pa = erofs_iloc(inode) + vi->inode_isize + 94 vi->xattr_isize + erofs_blkoff(sb, offset); 95 map->m_plen = inode->i_size - offset; 96 97 /* inline data should be located in the same meta block */ 98 if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { 99 erofs_err(sb, "inline data cross block boundary @ nid %llu", 100 vi->nid); 101 DBG_BUGON(1); 102 return -EFSCORRUPTED; 103 } 104 map->m_flags |= EROFS_MAP_META; 105 } else { 106 erofs_err(sb, "internal error @ nid: %llu (size %llu), m_la 0x%llx", 107 vi->nid, inode->i_size, map->m_la); 108 DBG_BUGON(1); 109 return -EIO; 110 } 111 return 0; 112 } 113 114 int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) 115 { 116 struct super_block *sb = inode->i_sb; 117 struct erofs_inode *vi = EROFS_I(inode); 118 struct erofs_inode_chunk_index *idx; 119 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 120 u64 chunknr; 121 unsigned int unit; 122 erofs_off_t pos; 123 void *kaddr; 124 int err = 0; 125 126 trace_erofs_map_blocks_enter(inode, map, 0); 127 map->m_deviceid = 0; 128 if (map->m_la >= inode->i_size) { 129 /* leave out-of-bound access unmapped */ 130 map->m_flags = 0; 131 map->m_plen = 0; 132 goto out; 133 } 134 135 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 136 err = erofs_map_blocks_flatmode(inode, map); 137 goto out; 138 } 139 140 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 141 unit = sizeof(*idx); /* chunk index */ 142 else 143 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 144 145 chunknr = map->m_la >> vi->chunkbits; 146 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + 147 vi->xattr_isize, unit) + unit * chunknr; 148 149 kaddr = erofs_read_metabuf(&buf, sb, pos, EROFS_KMAP); 150 if (IS_ERR(kaddr)) { 151 err = PTR_ERR(kaddr); 152 goto out; 153 } 154 map->m_la = chunknr << vi->chunkbits; 155 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 156 round_up(inode->i_size - map->m_la, sb->s_blocksize)); 157 158 /* handle block map */ 159 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 160 __le32 *blkaddr = kaddr; 161 162 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 163 map->m_flags = 0; 164 } else { 165 map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr)); 166 map->m_flags = EROFS_MAP_MAPPED; 167 } 168 goto out_unlock; 169 } 170 /* parse chunk indexes */ 171 idx = kaddr; 172 switch (le32_to_cpu(idx->blkaddr)) { 173 case EROFS_NULL_ADDR: 174 map->m_flags = 0; 175 break; 176 default: 177 map->m_deviceid = le16_to_cpu(idx->device_id) & 178 EROFS_SB(sb)->device_id_mask; 179 map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr)); 180 map->m_flags = EROFS_MAP_MAPPED; 181 break; 182 } 183 out_unlock: 184 erofs_put_metabuf(&buf); 185 out: 186 if (!err) 187 map->m_llen = map->m_plen; 188 trace_erofs_map_blocks_exit(inode, map, 0, err); 189 return err; 190 } 191 192 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 193 { 194 struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 195 struct erofs_device_info *dif; 196 int id; 197 198 map->m_bdev = sb->s_bdev; 199 map->m_daxdev = EROFS_SB(sb)->dax_dev; 200 map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; 201 map->m_fscache = EROFS_SB(sb)->s_fscache; 202 203 if (map->m_deviceid) { 204 down_read(&devs->rwsem); 205 dif = idr_find(&devs->tree, map->m_deviceid - 1); 206 if (!dif) { 207 up_read(&devs->rwsem); 208 return -ENODEV; 209 } 210 if (devs->flatdev) { 211 map->m_pa += erofs_pos(sb, dif->mapped_blkaddr); 212 up_read(&devs->rwsem); 213 return 0; 214 } 215 map->m_bdev = dif->bdev_file ? file_bdev(dif->bdev_file) : NULL; 216 map->m_daxdev = dif->dax_dev; 217 map->m_dax_part_off = dif->dax_part_off; 218 map->m_fscache = dif->fscache; 219 up_read(&devs->rwsem); 220 } else if (devs->extra_devices && !devs->flatdev) { 221 down_read(&devs->rwsem); 222 idr_for_each_entry(&devs->tree, dif, id) { 223 erofs_off_t startoff, length; 224 225 if (!dif->mapped_blkaddr) 226 continue; 227 startoff = erofs_pos(sb, dif->mapped_blkaddr); 228 length = erofs_pos(sb, dif->blocks); 229 230 if (map->m_pa >= startoff && 231 map->m_pa < startoff + length) { 232 map->m_pa -= startoff; 233 map->m_bdev = dif->bdev_file ? 234 file_bdev(dif->bdev_file) : NULL; 235 map->m_daxdev = dif->dax_dev; 236 map->m_dax_part_off = dif->dax_part_off; 237 map->m_fscache = dif->fscache; 238 break; 239 } 240 } 241 up_read(&devs->rwsem); 242 } 243 return 0; 244 } 245 246 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 247 unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 248 { 249 int ret; 250 struct super_block *sb = inode->i_sb; 251 struct erofs_map_blocks map; 252 struct erofs_map_dev mdev; 253 254 map.m_la = offset; 255 map.m_llen = length; 256 257 ret = erofs_map_blocks(inode, &map); 258 if (ret < 0) 259 return ret; 260 261 mdev = (struct erofs_map_dev) { 262 .m_deviceid = map.m_deviceid, 263 .m_pa = map.m_pa, 264 }; 265 ret = erofs_map_dev(sb, &mdev); 266 if (ret) 267 return ret; 268 269 iomap->offset = map.m_la; 270 if (flags & IOMAP_DAX) 271 iomap->dax_dev = mdev.m_daxdev; 272 else 273 iomap->bdev = mdev.m_bdev; 274 iomap->length = map.m_llen; 275 iomap->flags = 0; 276 iomap->private = NULL; 277 278 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 279 iomap->type = IOMAP_HOLE; 280 iomap->addr = IOMAP_NULL_ADDR; 281 if (!iomap->length) 282 iomap->length = length; 283 return 0; 284 } 285 286 if (map.m_flags & EROFS_MAP_META) { 287 void *ptr; 288 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 289 290 iomap->type = IOMAP_INLINE; 291 ptr = erofs_read_metabuf(&buf, sb, mdev.m_pa, EROFS_KMAP); 292 if (IS_ERR(ptr)) 293 return PTR_ERR(ptr); 294 iomap->inline_data = ptr; 295 iomap->private = buf.base; 296 } else { 297 iomap->type = IOMAP_MAPPED; 298 iomap->addr = mdev.m_pa; 299 if (flags & IOMAP_DAX) 300 iomap->addr += mdev.m_dax_part_off; 301 } 302 return 0; 303 } 304 305 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 306 ssize_t written, unsigned int flags, struct iomap *iomap) 307 { 308 void *ptr = iomap->private; 309 310 if (ptr) { 311 struct erofs_buf buf = { 312 .page = kmap_to_page(ptr), 313 .base = ptr, 314 .kmap_type = EROFS_KMAP, 315 }; 316 317 DBG_BUGON(iomap->type != IOMAP_INLINE); 318 erofs_put_metabuf(&buf); 319 } else { 320 DBG_BUGON(iomap->type == IOMAP_INLINE); 321 } 322 return written; 323 } 324 325 static const struct iomap_ops erofs_iomap_ops = { 326 .iomap_begin = erofs_iomap_begin, 327 .iomap_end = erofs_iomap_end, 328 }; 329 330 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 331 u64 start, u64 len) 332 { 333 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 334 #ifdef CONFIG_EROFS_FS_ZIP 335 return iomap_fiemap(inode, fieinfo, start, len, 336 &z_erofs_iomap_report_ops); 337 #else 338 return -EOPNOTSUPP; 339 #endif 340 } 341 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 342 } 343 344 /* 345 * since we dont have write or truncate flows, so no inode 346 * locking needs to be held at the moment. 347 */ 348 static int erofs_read_folio(struct file *file, struct folio *folio) 349 { 350 return iomap_read_folio(folio, &erofs_iomap_ops); 351 } 352 353 static void erofs_readahead(struct readahead_control *rac) 354 { 355 return iomap_readahead(rac, &erofs_iomap_ops); 356 } 357 358 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 359 { 360 return iomap_bmap(mapping, block, &erofs_iomap_ops); 361 } 362 363 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 364 { 365 struct inode *inode = file_inode(iocb->ki_filp); 366 367 /* no need taking (shared) inode lock since it's a ro filesystem */ 368 if (!iov_iter_count(to)) 369 return 0; 370 371 #ifdef CONFIG_FS_DAX 372 if (IS_DAX(inode)) 373 return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 374 #endif 375 if (iocb->ki_flags & IOCB_DIRECT) { 376 struct block_device *bdev = inode->i_sb->s_bdev; 377 unsigned int blksize_mask; 378 379 if (bdev) 380 blksize_mask = bdev_logical_block_size(bdev) - 1; 381 else 382 blksize_mask = i_blocksize(inode) - 1; 383 384 if ((iocb->ki_pos | iov_iter_count(to) | 385 iov_iter_alignment(to)) & blksize_mask) 386 return -EINVAL; 387 388 return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 389 NULL, 0, NULL, 0); 390 } 391 return filemap_read(iocb, to, 0); 392 } 393 394 /* for uncompressed (aligned) files and raw access for other files */ 395 const struct address_space_operations erofs_raw_access_aops = { 396 .read_folio = erofs_read_folio, 397 .readahead = erofs_readahead, 398 .bmap = erofs_bmap, 399 .direct_IO = noop_direct_IO, 400 .release_folio = iomap_release_folio, 401 .invalidate_folio = iomap_invalidate_folio, 402 }; 403 404 #ifdef CONFIG_FS_DAX 405 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 406 unsigned int order) 407 { 408 return dax_iomap_fault(vmf, order, NULL, NULL, &erofs_iomap_ops); 409 } 410 411 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 412 { 413 return erofs_dax_huge_fault(vmf, 0); 414 } 415 416 static const struct vm_operations_struct erofs_dax_vm_ops = { 417 .fault = erofs_dax_fault, 418 .huge_fault = erofs_dax_huge_fault, 419 }; 420 421 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 422 { 423 if (!IS_DAX(file_inode(file))) 424 return generic_file_readonly_mmap(file, vma); 425 426 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 427 return -EINVAL; 428 429 vma->vm_ops = &erofs_dax_vm_ops; 430 vm_flags_set(vma, VM_HUGEPAGE); 431 return 0; 432 } 433 #else 434 #define erofs_file_mmap generic_file_readonly_mmap 435 #endif 436 437 const struct file_operations erofs_file_fops = { 438 .llseek = generic_file_llseek, 439 .read_iter = erofs_file_read_iter, 440 .mmap = erofs_file_mmap, 441 .get_unmapped_area = thp_get_unmapped_area, 442 .splice_read = filemap_splice_read, 443 }; 444