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