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/dax.h> 10 #include <trace/events/erofs.h> 11 12 void erofs_unmap_metabuf(struct erofs_buf *buf) 13 { 14 if (buf->kmap_type == EROFS_KMAP) 15 kunmap(buf->page); 16 else if (buf->kmap_type == EROFS_KMAP_ATOMIC) 17 kunmap_atomic(buf->base); 18 buf->base = NULL; 19 buf->kmap_type = EROFS_NO_KMAP; 20 } 21 22 void erofs_put_metabuf(struct erofs_buf *buf) 23 { 24 if (!buf->page) 25 return; 26 erofs_unmap_metabuf(buf); 27 put_page(buf->page); 28 buf->page = NULL; 29 } 30 31 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 32 erofs_blk_t blkaddr, enum erofs_kmap_type type) 33 { 34 struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping; 35 erofs_off_t offset = blknr_to_addr(blkaddr); 36 pgoff_t index = offset >> PAGE_SHIFT; 37 struct page *page = buf->page; 38 39 if (!page || page->index != index) { 40 erofs_put_metabuf(buf); 41 page = read_cache_page_gfp(mapping, index, 42 mapping_gfp_constraint(mapping, ~__GFP_FS)); 43 if (IS_ERR(page)) 44 return page; 45 /* should already be PageUptodate, no need to lock page */ 46 buf->page = page; 47 } 48 if (buf->kmap_type == EROFS_NO_KMAP) { 49 if (type == EROFS_KMAP) 50 buf->base = kmap(page); 51 else if (type == EROFS_KMAP_ATOMIC) 52 buf->base = kmap_atomic(page); 53 buf->kmap_type = type; 54 } else if (buf->kmap_type != type) { 55 DBG_BUGON(1); 56 return ERR_PTR(-EFAULT); 57 } 58 if (type == EROFS_NO_KMAP) 59 return NULL; 60 return buf->base + (offset & ~PAGE_MASK); 61 } 62 63 static int erofs_map_blocks_flatmode(struct inode *inode, 64 struct erofs_map_blocks *map, 65 int flags) 66 { 67 erofs_blk_t nblocks, lastblk; 68 u64 offset = map->m_la; 69 struct erofs_inode *vi = EROFS_I(inode); 70 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 71 72 nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); 73 lastblk = nblocks - tailendpacking; 74 75 /* there is no hole in flatmode */ 76 map->m_flags = EROFS_MAP_MAPPED; 77 if (offset < blknr_to_addr(lastblk)) { 78 map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la; 79 map->m_plen = blknr_to_addr(lastblk) - offset; 80 } else if (tailendpacking) { 81 /* 2 - inode inline B: inode, [xattrs], inline last blk... */ 82 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); 83 84 map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize + 85 vi->xattr_isize + erofs_blkoff(map->m_la); 86 map->m_plen = inode->i_size - offset; 87 88 /* inline data should be located in the same meta block */ 89 if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) { 90 erofs_err(inode->i_sb, 91 "inline data cross block boundary @ nid %llu", 92 vi->nid); 93 DBG_BUGON(1); 94 return -EFSCORRUPTED; 95 } 96 map->m_flags |= EROFS_MAP_META; 97 } else { 98 erofs_err(inode->i_sb, 99 "internal error @ nid: %llu (size %llu), m_la 0x%llx", 100 vi->nid, inode->i_size, map->m_la); 101 DBG_BUGON(1); 102 return -EIO; 103 } 104 return 0; 105 } 106 107 static int erofs_map_blocks(struct inode *inode, 108 struct erofs_map_blocks *map, int flags) 109 { 110 struct super_block *sb = inode->i_sb; 111 struct erofs_inode *vi = EROFS_I(inode); 112 struct erofs_inode_chunk_index *idx; 113 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 114 u64 chunknr; 115 unsigned int unit; 116 erofs_off_t pos; 117 void *kaddr; 118 int err = 0; 119 120 trace_erofs_map_blocks_enter(inode, map, flags); 121 map->m_deviceid = 0; 122 if (map->m_la >= inode->i_size) { 123 /* leave out-of-bound access unmapped */ 124 map->m_flags = 0; 125 map->m_plen = 0; 126 goto out; 127 } 128 129 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 130 err = erofs_map_blocks_flatmode(inode, map, flags); 131 goto out; 132 } 133 134 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 135 unit = sizeof(*idx); /* chunk index */ 136 else 137 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 138 139 chunknr = map->m_la >> vi->chunkbits; 140 pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize + 141 vi->xattr_isize, unit) + unit * chunknr; 142 143 kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP); 144 if (IS_ERR(kaddr)) { 145 err = PTR_ERR(kaddr); 146 goto out; 147 } 148 map->m_la = chunknr << vi->chunkbits; 149 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 150 roundup(inode->i_size - map->m_la, EROFS_BLKSIZ)); 151 152 /* handle block map */ 153 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 154 __le32 *blkaddr = kaddr + erofs_blkoff(pos); 155 156 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 157 map->m_flags = 0; 158 } else { 159 map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr)); 160 map->m_flags = EROFS_MAP_MAPPED; 161 } 162 goto out_unlock; 163 } 164 /* parse chunk indexes */ 165 idx = kaddr + erofs_blkoff(pos); 166 switch (le32_to_cpu(idx->blkaddr)) { 167 case EROFS_NULL_ADDR: 168 map->m_flags = 0; 169 break; 170 default: 171 map->m_deviceid = le16_to_cpu(idx->device_id) & 172 EROFS_SB(sb)->device_id_mask; 173 map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr)); 174 map->m_flags = EROFS_MAP_MAPPED; 175 break; 176 } 177 out_unlock: 178 erofs_put_metabuf(&buf); 179 out: 180 if (!err) 181 map->m_llen = map->m_plen; 182 trace_erofs_map_blocks_exit(inode, map, flags, 0); 183 return err; 184 } 185 186 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 187 { 188 struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 189 struct erofs_device_info *dif; 190 int id; 191 192 /* primary device by default */ 193 map->m_bdev = sb->s_bdev; 194 map->m_daxdev = EROFS_SB(sb)->dax_dev; 195 map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; 196 197 if (map->m_deviceid) { 198 down_read(&devs->rwsem); 199 dif = idr_find(&devs->tree, map->m_deviceid - 1); 200 if (!dif) { 201 up_read(&devs->rwsem); 202 return -ENODEV; 203 } 204 map->m_bdev = dif->bdev; 205 map->m_daxdev = dif->dax_dev; 206 map->m_dax_part_off = dif->dax_part_off; 207 up_read(&devs->rwsem); 208 } else if (devs->extra_devices) { 209 down_read(&devs->rwsem); 210 idr_for_each_entry(&devs->tree, dif, id) { 211 erofs_off_t startoff, length; 212 213 if (!dif->mapped_blkaddr) 214 continue; 215 startoff = blknr_to_addr(dif->mapped_blkaddr); 216 length = blknr_to_addr(dif->blocks); 217 218 if (map->m_pa >= startoff && 219 map->m_pa < startoff + length) { 220 map->m_pa -= startoff; 221 map->m_bdev = dif->bdev; 222 map->m_daxdev = dif->dax_dev; 223 map->m_dax_part_off = dif->dax_part_off; 224 break; 225 } 226 } 227 up_read(&devs->rwsem); 228 } 229 return 0; 230 } 231 232 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 233 unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 234 { 235 int ret; 236 struct erofs_map_blocks map; 237 struct erofs_map_dev mdev; 238 239 map.m_la = offset; 240 map.m_llen = length; 241 242 ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW); 243 if (ret < 0) 244 return ret; 245 246 mdev = (struct erofs_map_dev) { 247 .m_deviceid = map.m_deviceid, 248 .m_pa = map.m_pa, 249 }; 250 ret = erofs_map_dev(inode->i_sb, &mdev); 251 if (ret) 252 return ret; 253 254 iomap->offset = map.m_la; 255 if (flags & IOMAP_DAX) 256 iomap->dax_dev = mdev.m_daxdev; 257 else 258 iomap->bdev = mdev.m_bdev; 259 iomap->length = map.m_llen; 260 iomap->flags = 0; 261 iomap->private = NULL; 262 263 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 264 iomap->type = IOMAP_HOLE; 265 iomap->addr = IOMAP_NULL_ADDR; 266 if (!iomap->length) 267 iomap->length = length; 268 return 0; 269 } 270 271 if (map.m_flags & EROFS_MAP_META) { 272 void *ptr; 273 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 274 275 iomap->type = IOMAP_INLINE; 276 ptr = erofs_read_metabuf(&buf, inode->i_sb, 277 erofs_blknr(mdev.m_pa), EROFS_KMAP); 278 if (IS_ERR(ptr)) 279 return PTR_ERR(ptr); 280 iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa); 281 iomap->private = buf.base; 282 } else { 283 iomap->type = IOMAP_MAPPED; 284 iomap->addr = mdev.m_pa; 285 if (flags & IOMAP_DAX) 286 iomap->addr += mdev.m_dax_part_off; 287 } 288 return 0; 289 } 290 291 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 292 ssize_t written, unsigned int flags, struct iomap *iomap) 293 { 294 void *ptr = iomap->private; 295 296 if (ptr) { 297 struct erofs_buf buf = { 298 .page = kmap_to_page(ptr), 299 .base = ptr, 300 .kmap_type = EROFS_KMAP, 301 }; 302 303 DBG_BUGON(iomap->type != IOMAP_INLINE); 304 erofs_put_metabuf(&buf); 305 } else { 306 DBG_BUGON(iomap->type == IOMAP_INLINE); 307 } 308 return written; 309 } 310 311 static const struct iomap_ops erofs_iomap_ops = { 312 .iomap_begin = erofs_iomap_begin, 313 .iomap_end = erofs_iomap_end, 314 }; 315 316 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 317 u64 start, u64 len) 318 { 319 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 320 #ifdef CONFIG_EROFS_FS_ZIP 321 return iomap_fiemap(inode, fieinfo, start, len, 322 &z_erofs_iomap_report_ops); 323 #else 324 return -EOPNOTSUPP; 325 #endif 326 } 327 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 328 } 329 330 /* 331 * since we dont have write or truncate flows, so no inode 332 * locking needs to be held at the moment. 333 */ 334 static int erofs_readpage(struct file *file, struct page *page) 335 { 336 return iomap_readpage(page, &erofs_iomap_ops); 337 } 338 339 static void erofs_readahead(struct readahead_control *rac) 340 { 341 return iomap_readahead(rac, &erofs_iomap_ops); 342 } 343 344 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 345 { 346 return iomap_bmap(mapping, block, &erofs_iomap_ops); 347 } 348 349 static int erofs_prepare_dio(struct kiocb *iocb, struct iov_iter *to) 350 { 351 struct inode *inode = file_inode(iocb->ki_filp); 352 loff_t align = iocb->ki_pos | iov_iter_count(to) | 353 iov_iter_alignment(to); 354 struct block_device *bdev = inode->i_sb->s_bdev; 355 unsigned int blksize_mask; 356 357 if (bdev) 358 blksize_mask = (1 << ilog2(bdev_logical_block_size(bdev))) - 1; 359 else 360 blksize_mask = (1 << inode->i_blkbits) - 1; 361 362 if (align & blksize_mask) 363 return -EINVAL; 364 return 0; 365 } 366 367 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 368 { 369 /* no need taking (shared) inode lock since it's a ro filesystem */ 370 if (!iov_iter_count(to)) 371 return 0; 372 373 #ifdef CONFIG_FS_DAX 374 if (IS_DAX(iocb->ki_filp->f_mapping->host)) 375 return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 376 #endif 377 if (iocb->ki_flags & IOCB_DIRECT) { 378 int err = erofs_prepare_dio(iocb, to); 379 380 if (!err) 381 return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 382 NULL, 0, 0); 383 if (err < 0) 384 return err; 385 } 386 return filemap_read(iocb, to, 0); 387 } 388 389 /* for uncompressed (aligned) files and raw access for other files */ 390 const struct address_space_operations erofs_raw_access_aops = { 391 .readpage = erofs_readpage, 392 .readahead = erofs_readahead, 393 .bmap = erofs_bmap, 394 .direct_IO = noop_direct_IO, 395 }; 396 397 #ifdef CONFIG_FS_DAX 398 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 399 enum page_entry_size pe_size) 400 { 401 return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops); 402 } 403 404 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 405 { 406 return erofs_dax_huge_fault(vmf, PE_SIZE_PTE); 407 } 408 409 static const struct vm_operations_struct erofs_dax_vm_ops = { 410 .fault = erofs_dax_fault, 411 .huge_fault = erofs_dax_huge_fault, 412 }; 413 414 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 415 { 416 if (!IS_DAX(file_inode(file))) 417 return generic_file_readonly_mmap(file, vma); 418 419 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 420 return -EINVAL; 421 422 vma->vm_ops = &erofs_dax_vm_ops; 423 vma->vm_flags |= VM_HUGEPAGE; 424 return 0; 425 } 426 #else 427 #define erofs_file_mmap generic_file_readonly_mmap 428 #endif 429 430 const struct file_operations erofs_file_fops = { 431 .llseek = generic_file_llseek, 432 .read_iter = erofs_file_read_iter, 433 .mmap = erofs_file_mmap, 434 .splice_read = generic_file_splice_read, 435 }; 436