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(buf->page); 17 else if (buf->kmap_type == EROFS_KMAP_ATOMIC) 18 kunmap_atomic(buf->base); 19 buf->base = NULL; 20 buf->kmap_type = EROFS_NO_KMAP; 21 } 22 23 void erofs_put_metabuf(struct erofs_buf *buf) 24 { 25 if (!buf->page) 26 return; 27 erofs_unmap_metabuf(buf); 28 put_page(buf->page); 29 buf->page = NULL; 30 } 31 32 void *erofs_bread(struct erofs_buf *buf, struct inode *inode, 33 erofs_blk_t blkaddr, enum erofs_kmap_type type) 34 { 35 struct address_space *const mapping = inode->i_mapping; 36 erofs_off_t offset = blknr_to_addr(blkaddr); 37 pgoff_t index = offset >> PAGE_SHIFT; 38 struct page *page = buf->page; 39 struct folio *folio; 40 unsigned int nofs_flag; 41 42 if (!page || page->index != index) { 43 erofs_put_metabuf(buf); 44 45 nofs_flag = memalloc_nofs_save(); 46 folio = read_cache_folio(mapping, index, NULL, NULL); 47 memalloc_nofs_restore(nofs_flag); 48 if (IS_ERR(folio)) 49 return folio; 50 51 /* should already be PageUptodate, no need to lock page */ 52 page = folio_file_page(folio, index); 53 buf->page = page; 54 } 55 if (buf->kmap_type == EROFS_NO_KMAP) { 56 if (type == EROFS_KMAP) 57 buf->base = kmap(page); 58 else if (type == EROFS_KMAP_ATOMIC) 59 buf->base = kmap_atomic(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_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 71 erofs_blk_t blkaddr, enum erofs_kmap_type type) 72 { 73 if (erofs_is_fscache_mode(sb)) 74 return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode, 75 blkaddr, type); 76 77 return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type); 78 } 79 80 static int erofs_map_blocks_flatmode(struct inode *inode, 81 struct erofs_map_blocks *map, 82 int flags) 83 { 84 erofs_blk_t nblocks, lastblk; 85 u64 offset = map->m_la; 86 struct erofs_inode *vi = EROFS_I(inode); 87 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 88 89 nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); 90 lastblk = nblocks - tailendpacking; 91 92 /* there is no hole in flatmode */ 93 map->m_flags = EROFS_MAP_MAPPED; 94 if (offset < blknr_to_addr(lastblk)) { 95 map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la; 96 map->m_plen = blknr_to_addr(lastblk) - offset; 97 } else if (tailendpacking) { 98 /* 2 - inode inline B: inode, [xattrs], inline last blk... */ 99 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); 100 101 map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize + 102 vi->xattr_isize + erofs_blkoff(map->m_la); 103 map->m_plen = inode->i_size - offset; 104 105 /* inline data should be located in the same meta block */ 106 if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) { 107 erofs_err(inode->i_sb, 108 "inline data cross block boundary @ nid %llu", 109 vi->nid); 110 DBG_BUGON(1); 111 return -EFSCORRUPTED; 112 } 113 map->m_flags |= EROFS_MAP_META; 114 } else { 115 erofs_err(inode->i_sb, 116 "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, 125 struct erofs_map_blocks *map, int flags) 126 { 127 struct super_block *sb = inode->i_sb; 128 struct erofs_inode *vi = EROFS_I(inode); 129 struct erofs_inode_chunk_index *idx; 130 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 131 u64 chunknr; 132 unsigned int unit; 133 erofs_off_t pos; 134 void *kaddr; 135 int err = 0; 136 137 trace_erofs_map_blocks_enter(inode, map, flags); 138 map->m_deviceid = 0; 139 if (map->m_la >= inode->i_size) { 140 /* leave out-of-bound access unmapped */ 141 map->m_flags = 0; 142 map->m_plen = 0; 143 goto out; 144 } 145 146 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 147 err = erofs_map_blocks_flatmode(inode, map, flags); 148 goto out; 149 } 150 151 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 152 unit = sizeof(*idx); /* chunk index */ 153 else 154 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 155 156 chunknr = map->m_la >> vi->chunkbits; 157 pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize + 158 vi->xattr_isize, unit) + unit * chunknr; 159 160 kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP); 161 if (IS_ERR(kaddr)) { 162 err = PTR_ERR(kaddr); 163 goto out; 164 } 165 map->m_la = chunknr << vi->chunkbits; 166 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 167 roundup(inode->i_size - map->m_la, EROFS_BLKSIZ)); 168 169 /* handle block map */ 170 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 171 __le32 *blkaddr = kaddr + erofs_blkoff(pos); 172 173 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 174 map->m_flags = 0; 175 } else { 176 map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr)); 177 map->m_flags = EROFS_MAP_MAPPED; 178 } 179 goto out_unlock; 180 } 181 /* parse chunk indexes */ 182 idx = kaddr + erofs_blkoff(pos); 183 switch (le32_to_cpu(idx->blkaddr)) { 184 case EROFS_NULL_ADDR: 185 map->m_flags = 0; 186 break; 187 default: 188 map->m_deviceid = le16_to_cpu(idx->device_id) & 189 EROFS_SB(sb)->device_id_mask; 190 map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr)); 191 map->m_flags = EROFS_MAP_MAPPED; 192 break; 193 } 194 out_unlock: 195 erofs_put_metabuf(&buf); 196 out: 197 if (!err) 198 map->m_llen = map->m_plen; 199 trace_erofs_map_blocks_exit(inode, map, flags, 0); 200 return err; 201 } 202 203 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 204 { 205 struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 206 struct erofs_device_info *dif; 207 int id; 208 209 /* primary device by default */ 210 map->m_bdev = sb->s_bdev; 211 map->m_daxdev = EROFS_SB(sb)->dax_dev; 212 map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; 213 map->m_fscache = EROFS_SB(sb)->s_fscache; 214 215 if (map->m_deviceid) { 216 down_read(&devs->rwsem); 217 dif = idr_find(&devs->tree, map->m_deviceid - 1); 218 if (!dif) { 219 up_read(&devs->rwsem); 220 return -ENODEV; 221 } 222 map->m_bdev = dif->bdev; 223 map->m_daxdev = dif->dax_dev; 224 map->m_dax_part_off = dif->dax_part_off; 225 map->m_fscache = dif->fscache; 226 up_read(&devs->rwsem); 227 } else if (devs->extra_devices) { 228 down_read(&devs->rwsem); 229 idr_for_each_entry(&devs->tree, dif, id) { 230 erofs_off_t startoff, length; 231 232 if (!dif->mapped_blkaddr) 233 continue; 234 startoff = blknr_to_addr(dif->mapped_blkaddr); 235 length = blknr_to_addr(dif->blocks); 236 237 if (map->m_pa >= startoff && 238 map->m_pa < startoff + length) { 239 map->m_pa -= startoff; 240 map->m_bdev = dif->bdev; 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 erofs_map_blocks map; 257 struct erofs_map_dev mdev; 258 259 map.m_la = offset; 260 map.m_llen = length; 261 262 ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW); 263 if (ret < 0) 264 return ret; 265 266 mdev = (struct erofs_map_dev) { 267 .m_deviceid = map.m_deviceid, 268 .m_pa = map.m_pa, 269 }; 270 ret = erofs_map_dev(inode->i_sb, &mdev); 271 if (ret) 272 return ret; 273 274 iomap->offset = map.m_la; 275 if (flags & IOMAP_DAX) 276 iomap->dax_dev = mdev.m_daxdev; 277 else 278 iomap->bdev = mdev.m_bdev; 279 iomap->length = map.m_llen; 280 iomap->flags = 0; 281 iomap->private = NULL; 282 283 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 284 iomap->type = IOMAP_HOLE; 285 iomap->addr = IOMAP_NULL_ADDR; 286 if (!iomap->length) 287 iomap->length = length; 288 return 0; 289 } 290 291 if (map.m_flags & EROFS_MAP_META) { 292 void *ptr; 293 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 294 295 iomap->type = IOMAP_INLINE; 296 ptr = erofs_read_metabuf(&buf, inode->i_sb, 297 erofs_blknr(mdev.m_pa), EROFS_KMAP); 298 if (IS_ERR(ptr)) 299 return PTR_ERR(ptr); 300 iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa); 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 = (1 << inode->i_blkbits) - 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 }; 407 408 #ifdef CONFIG_FS_DAX 409 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 410 enum page_entry_size pe_size) 411 { 412 return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops); 413 } 414 415 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 416 { 417 return erofs_dax_huge_fault(vmf, PE_SIZE_PTE); 418 } 419 420 static const struct vm_operations_struct erofs_dax_vm_ops = { 421 .fault = erofs_dax_fault, 422 .huge_fault = erofs_dax_huge_fault, 423 }; 424 425 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 426 { 427 if (!IS_DAX(file_inode(file))) 428 return generic_file_readonly_mmap(file, vma); 429 430 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 431 return -EINVAL; 432 433 vma->vm_ops = &erofs_dax_vm_ops; 434 vma->vm_flags |= VM_HUGEPAGE; 435 return 0; 436 } 437 #else 438 #define erofs_file_mmap generic_file_readonly_mmap 439 #endif 440 441 const struct file_operations erofs_file_fops = { 442 .llseek = generic_file_llseek, 443 .read_iter = erofs_file_read_iter, 444 .mmap = erofs_file_mmap, 445 .splice_read = generic_file_splice_read, 446 }; 447