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