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 put_page(buf->page); 25 buf->page = NULL; 26 } 27 28 /* 29 * Derive the block size from inode->i_blkbits to make compatible with 30 * anonymous inode in fscache mode. 31 */ 32 void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset, 33 enum erofs_kmap_type type) 34 { 35 pgoff_t index = offset >> PAGE_SHIFT; 36 struct page *page = buf->page; 37 struct folio *folio; 38 unsigned int nofs_flag; 39 40 if (!page || page->index != index) { 41 erofs_put_metabuf(buf); 42 43 nofs_flag = memalloc_nofs_save(); 44 folio = read_cache_folio(buf->mapping, index, NULL, NULL); 45 memalloc_nofs_restore(nofs_flag); 46 if (IS_ERR(folio)) 47 return folio; 48 49 /* should already be PageUptodate, no need to lock page */ 50 page = folio_file_page(folio, index); 51 buf->page = page; 52 } 53 if (buf->kmap_type == EROFS_NO_KMAP) { 54 if (type == EROFS_KMAP) 55 buf->base = kmap_local_page(page); 56 buf->kmap_type = type; 57 } else if (buf->kmap_type != type) { 58 DBG_BUGON(1); 59 return ERR_PTR(-EFAULT); 60 } 61 if (type == EROFS_NO_KMAP) 62 return NULL; 63 return buf->base + (offset & ~PAGE_MASK); 64 } 65 66 void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb) 67 { 68 if (erofs_is_fscache_mode(sb)) 69 buf->mapping = EROFS_SB(sb)->s_fscache->inode->i_mapping; 70 else 71 buf->mapping = sb->s_bdev->bd_mapping; 72 } 73 74 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 75 erofs_off_t offset, enum erofs_kmap_type type) 76 { 77 erofs_init_metabuf(buf, sb); 78 return erofs_bread(buf, offset, type); 79 } 80 81 static int erofs_map_blocks_flatmode(struct inode *inode, 82 struct erofs_map_blocks *map) 83 { 84 erofs_blk_t nblocks, lastblk; 85 u64 offset = map->m_la; 86 struct erofs_inode *vi = EROFS_I(inode); 87 struct super_block *sb = inode->i_sb; 88 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 89 90 nblocks = erofs_iblks(inode); 91 lastblk = nblocks - tailendpacking; 92 93 /* there is no hole in flatmode */ 94 map->m_flags = EROFS_MAP_MAPPED; 95 if (offset < erofs_pos(sb, lastblk)) { 96 map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la; 97 map->m_plen = erofs_pos(sb, lastblk) - offset; 98 } else if (tailendpacking) { 99 map->m_pa = erofs_iloc(inode) + vi->inode_isize + 100 vi->xattr_isize + erofs_blkoff(sb, offset); 101 map->m_plen = inode->i_size - offset; 102 103 /* inline data should be located in the same meta block */ 104 if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { 105 erofs_err(sb, "inline data cross block boundary @ nid %llu", 106 vi->nid); 107 DBG_BUGON(1); 108 return -EFSCORRUPTED; 109 } 110 map->m_flags |= EROFS_MAP_META; 111 } else { 112 erofs_err(sb, "internal error @ nid: %llu (size %llu), m_la 0x%llx", 113 vi->nid, inode->i_size, map->m_la); 114 DBG_BUGON(1); 115 return -EIO; 116 } 117 return 0; 118 } 119 120 int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) 121 { 122 struct super_block *sb = inode->i_sb; 123 struct erofs_inode *vi = EROFS_I(inode); 124 struct erofs_inode_chunk_index *idx; 125 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 126 u64 chunknr; 127 unsigned int unit; 128 erofs_off_t pos; 129 void *kaddr; 130 int err = 0; 131 132 trace_erofs_map_blocks_enter(inode, map, 0); 133 map->m_deviceid = 0; 134 if (map->m_la >= inode->i_size) { 135 /* leave out-of-bound access unmapped */ 136 map->m_flags = 0; 137 map->m_plen = 0; 138 goto out; 139 } 140 141 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 142 err = erofs_map_blocks_flatmode(inode, map); 143 goto out; 144 } 145 146 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 147 unit = sizeof(*idx); /* chunk index */ 148 else 149 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 150 151 chunknr = map->m_la >> vi->chunkbits; 152 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + 153 vi->xattr_isize, unit) + unit * chunknr; 154 155 kaddr = erofs_read_metabuf(&buf, sb, pos, EROFS_KMAP); 156 if (IS_ERR(kaddr)) { 157 err = PTR_ERR(kaddr); 158 goto out; 159 } 160 map->m_la = chunknr << vi->chunkbits; 161 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 162 round_up(inode->i_size - map->m_la, sb->s_blocksize)); 163 164 /* handle block map */ 165 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 166 __le32 *blkaddr = kaddr; 167 168 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 169 map->m_flags = 0; 170 } else { 171 map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr)); 172 map->m_flags = EROFS_MAP_MAPPED; 173 } 174 goto out_unlock; 175 } 176 /* parse chunk indexes */ 177 idx = kaddr; 178 switch (le32_to_cpu(idx->blkaddr)) { 179 case EROFS_NULL_ADDR: 180 map->m_flags = 0; 181 break; 182 default: 183 map->m_deviceid = le16_to_cpu(idx->device_id) & 184 EROFS_SB(sb)->device_id_mask; 185 map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr)); 186 map->m_flags = EROFS_MAP_MAPPED; 187 break; 188 } 189 out_unlock: 190 erofs_put_metabuf(&buf); 191 out: 192 if (!err) 193 map->m_llen = map->m_plen; 194 trace_erofs_map_blocks_exit(inode, map, 0, err); 195 return err; 196 } 197 198 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 199 { 200 struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 201 struct erofs_device_info *dif; 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; 208 209 if (map->m_deviceid) { 210 down_read(&devs->rwsem); 211 dif = idr_find(&devs->tree, map->m_deviceid - 1); 212 if (!dif) { 213 up_read(&devs->rwsem); 214 return -ENODEV; 215 } 216 if (devs->flatdev) { 217 map->m_pa += erofs_pos(sb, dif->mapped_blkaddr); 218 up_read(&devs->rwsem); 219 return 0; 220 } 221 map->m_bdev = dif->bdev_file ? file_bdev(dif->bdev_file) : NULL; 222 map->m_daxdev = dif->dax_dev; 223 map->m_dax_part_off = dif->dax_part_off; 224 map->m_fscache = dif->fscache; 225 up_read(&devs->rwsem); 226 } else if (devs->extra_devices && !devs->flatdev) { 227 down_read(&devs->rwsem); 228 idr_for_each_entry(&devs->tree, dif, id) { 229 erofs_off_t startoff, length; 230 231 if (!dif->mapped_blkaddr) 232 continue; 233 startoff = erofs_pos(sb, dif->mapped_blkaddr); 234 length = erofs_pos(sb, dif->blocks); 235 236 if (map->m_pa >= startoff && 237 map->m_pa < startoff + length) { 238 map->m_pa -= startoff; 239 map->m_bdev = dif->bdev_file ? 240 file_bdev(dif->bdev_file) : NULL; 241 map->m_daxdev = dif->dax_dev; 242 map->m_dax_part_off = dif->dax_part_off; 243 map->m_fscache = dif->fscache; 244 break; 245 } 246 } 247 up_read(&devs->rwsem); 248 } 249 return 0; 250 } 251 252 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 253 unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 254 { 255 int ret; 256 struct super_block *sb = inode->i_sb; 257 struct erofs_map_blocks map; 258 struct erofs_map_dev mdev; 259 260 map.m_la = offset; 261 map.m_llen = length; 262 263 ret = erofs_map_blocks(inode, &map); 264 if (ret < 0) 265 return ret; 266 267 mdev = (struct erofs_map_dev) { 268 .m_deviceid = map.m_deviceid, 269 .m_pa = map.m_pa, 270 }; 271 ret = erofs_map_dev(sb, &mdev); 272 if (ret) 273 return ret; 274 275 iomap->offset = map.m_la; 276 if (flags & IOMAP_DAX) 277 iomap->dax_dev = mdev.m_daxdev; 278 else 279 iomap->bdev = mdev.m_bdev; 280 iomap->length = map.m_llen; 281 iomap->flags = 0; 282 iomap->private = NULL; 283 284 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 285 iomap->type = IOMAP_HOLE; 286 iomap->addr = IOMAP_NULL_ADDR; 287 if (!iomap->length) 288 iomap->length = length; 289 return 0; 290 } 291 292 if (map.m_flags & EROFS_MAP_META) { 293 void *ptr; 294 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 295 296 iomap->type = IOMAP_INLINE; 297 ptr = erofs_read_metabuf(&buf, sb, mdev.m_pa, EROFS_KMAP); 298 if (IS_ERR(ptr)) 299 return PTR_ERR(ptr); 300 iomap->inline_data = ptr; 301 iomap->private = buf.base; 302 } else { 303 iomap->type = IOMAP_MAPPED; 304 iomap->addr = mdev.m_pa; 305 if (flags & IOMAP_DAX) 306 iomap->addr += mdev.m_dax_part_off; 307 } 308 return 0; 309 } 310 311 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 312 ssize_t written, unsigned int flags, struct iomap *iomap) 313 { 314 void *ptr = iomap->private; 315 316 if (ptr) { 317 struct erofs_buf buf = { 318 .page = kmap_to_page(ptr), 319 .base = ptr, 320 .kmap_type = EROFS_KMAP, 321 }; 322 323 DBG_BUGON(iomap->type != IOMAP_INLINE); 324 erofs_put_metabuf(&buf); 325 } else { 326 DBG_BUGON(iomap->type == IOMAP_INLINE); 327 } 328 return written; 329 } 330 331 static const struct iomap_ops erofs_iomap_ops = { 332 .iomap_begin = erofs_iomap_begin, 333 .iomap_end = erofs_iomap_end, 334 }; 335 336 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 337 u64 start, u64 len) 338 { 339 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 340 #ifdef CONFIG_EROFS_FS_ZIP 341 return iomap_fiemap(inode, fieinfo, start, len, 342 &z_erofs_iomap_report_ops); 343 #else 344 return -EOPNOTSUPP; 345 #endif 346 } 347 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 348 } 349 350 /* 351 * since we dont have write or truncate flows, so no inode 352 * locking needs to be held at the moment. 353 */ 354 static int erofs_read_folio(struct file *file, struct folio *folio) 355 { 356 return iomap_read_folio(folio, &erofs_iomap_ops); 357 } 358 359 static void erofs_readahead(struct readahead_control *rac) 360 { 361 return iomap_readahead(rac, &erofs_iomap_ops); 362 } 363 364 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 365 { 366 return iomap_bmap(mapping, block, &erofs_iomap_ops); 367 } 368 369 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 370 { 371 struct inode *inode = file_inode(iocb->ki_filp); 372 373 /* no need taking (shared) inode lock since it's a ro filesystem */ 374 if (!iov_iter_count(to)) 375 return 0; 376 377 #ifdef CONFIG_FS_DAX 378 if (IS_DAX(inode)) 379 return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 380 #endif 381 if (iocb->ki_flags & IOCB_DIRECT) { 382 struct block_device *bdev = inode->i_sb->s_bdev; 383 unsigned int blksize_mask; 384 385 if (bdev) 386 blksize_mask = bdev_logical_block_size(bdev) - 1; 387 else 388 blksize_mask = i_blocksize(inode) - 1; 389 390 if ((iocb->ki_pos | iov_iter_count(to) | 391 iov_iter_alignment(to)) & blksize_mask) 392 return -EINVAL; 393 394 return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 395 NULL, 0, NULL, 0); 396 } 397 return filemap_read(iocb, to, 0); 398 } 399 400 /* for uncompressed (aligned) files and raw access for other files */ 401 const struct address_space_operations erofs_raw_access_aops = { 402 .read_folio = erofs_read_folio, 403 .readahead = erofs_readahead, 404 .bmap = erofs_bmap, 405 .direct_IO = noop_direct_IO, 406 .release_folio = iomap_release_folio, 407 .invalidate_folio = iomap_invalidate_folio, 408 }; 409 410 #ifdef CONFIG_FS_DAX 411 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 412 unsigned int order) 413 { 414 return dax_iomap_fault(vmf, order, NULL, NULL, &erofs_iomap_ops); 415 } 416 417 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 418 { 419 return erofs_dax_huge_fault(vmf, 0); 420 } 421 422 static const struct vm_operations_struct erofs_dax_vm_ops = { 423 .fault = erofs_dax_fault, 424 .huge_fault = erofs_dax_huge_fault, 425 }; 426 427 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 428 { 429 if (!IS_DAX(file_inode(file))) 430 return generic_file_readonly_mmap(file, vma); 431 432 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 433 return -EINVAL; 434 435 vma->vm_ops = &erofs_dax_vm_ops; 436 vm_flags_set(vma, VM_HUGEPAGE); 437 return 0; 438 } 439 #else 440 #define erofs_file_mmap generic_file_readonly_mmap 441 #endif 442 443 const struct file_operations erofs_file_fops = { 444 .llseek = generic_file_llseek, 445 .read_iter = erofs_file_read_iter, 446 .mmap = erofs_file_mmap, 447 .get_unmapped_area = thp_get_unmapped_area, 448 .splice_read = filemap_splice_read, 449 }; 450