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 if (map->m_la >= inode->i_size) { 93 /* leave out-of-bound access unmapped */ 94 map->m_flags = 0; 95 map->m_plen = 0; 96 goto out; 97 } 98 99 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) 100 return erofs_map_blocks_flatmode(inode, map, flags); 101 102 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 103 unit = sizeof(*idx); /* chunk index */ 104 else 105 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 106 107 chunknr = map->m_la >> vi->chunkbits; 108 pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize + 109 vi->xattr_isize, unit) + unit * chunknr; 110 111 page = erofs_get_meta_page(inode->i_sb, erofs_blknr(pos)); 112 if (IS_ERR(page)) 113 return PTR_ERR(page); 114 115 map->m_la = chunknr << vi->chunkbits; 116 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 117 roundup(inode->i_size - map->m_la, EROFS_BLKSIZ)); 118 119 /* handle block map */ 120 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 121 __le32 *blkaddr = page_address(page) + erofs_blkoff(pos); 122 123 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 124 map->m_flags = 0; 125 } else { 126 map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr)); 127 map->m_flags = EROFS_MAP_MAPPED; 128 } 129 goto out_unlock; 130 } 131 /* parse chunk indexes */ 132 idx = page_address(page) + erofs_blkoff(pos); 133 switch (le32_to_cpu(idx->blkaddr)) { 134 case EROFS_NULL_ADDR: 135 map->m_flags = 0; 136 break; 137 default: 138 /* only one device is supported for now */ 139 if (idx->device_id) { 140 erofs_err(sb, "invalid device id %u @ %llu for nid %llu", 141 le16_to_cpu(idx->device_id), 142 chunknr, vi->nid); 143 err = -EFSCORRUPTED; 144 goto out_unlock; 145 } 146 map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr)); 147 map->m_flags = EROFS_MAP_MAPPED; 148 break; 149 } 150 out_unlock: 151 unlock_page(page); 152 put_page(page); 153 out: 154 map->m_llen = map->m_plen; 155 return err; 156 } 157 158 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 159 unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 160 { 161 int ret; 162 struct erofs_map_blocks map; 163 164 map.m_la = offset; 165 map.m_llen = length; 166 167 ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW); 168 if (ret < 0) 169 return ret; 170 171 iomap->bdev = inode->i_sb->s_bdev; 172 iomap->dax_dev = EROFS_I_SB(inode)->dax_dev; 173 iomap->offset = map.m_la; 174 iomap->length = map.m_llen; 175 iomap->flags = 0; 176 iomap->private = NULL; 177 178 if (!(map.m_flags & EROFS_MAP_MAPPED)) { 179 iomap->type = IOMAP_HOLE; 180 iomap->addr = IOMAP_NULL_ADDR; 181 if (!iomap->length) 182 iomap->length = length; 183 return 0; 184 } 185 186 if (map.m_flags & EROFS_MAP_META) { 187 struct page *ipage; 188 189 iomap->type = IOMAP_INLINE; 190 ipage = erofs_get_meta_page(inode->i_sb, 191 erofs_blknr(map.m_pa)); 192 if (IS_ERR(ipage)) 193 return PTR_ERR(ipage); 194 iomap->inline_data = page_address(ipage) + 195 erofs_blkoff(map.m_pa); 196 iomap->private = ipage; 197 } else { 198 iomap->type = IOMAP_MAPPED; 199 iomap->addr = map.m_pa; 200 } 201 return 0; 202 } 203 204 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 205 ssize_t written, unsigned int flags, struct iomap *iomap) 206 { 207 struct page *ipage = iomap->private; 208 209 if (ipage) { 210 DBG_BUGON(iomap->type != IOMAP_INLINE); 211 unlock_page(ipage); 212 put_page(ipage); 213 } else { 214 DBG_BUGON(iomap->type == IOMAP_INLINE); 215 } 216 return written; 217 } 218 219 static const struct iomap_ops erofs_iomap_ops = { 220 .iomap_begin = erofs_iomap_begin, 221 .iomap_end = erofs_iomap_end, 222 }; 223 224 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 225 u64 start, u64 len) 226 { 227 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 228 #ifdef CONFIG_EROFS_FS_ZIP 229 return iomap_fiemap(inode, fieinfo, start, len, 230 &z_erofs_iomap_report_ops); 231 #else 232 return -EOPNOTSUPP; 233 #endif 234 } 235 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 236 } 237 238 /* 239 * since we dont have write or truncate flows, so no inode 240 * locking needs to be held at the moment. 241 */ 242 static int erofs_readpage(struct file *file, struct page *page) 243 { 244 return iomap_readpage(page, &erofs_iomap_ops); 245 } 246 247 static void erofs_readahead(struct readahead_control *rac) 248 { 249 return iomap_readahead(rac, &erofs_iomap_ops); 250 } 251 252 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 253 { 254 return iomap_bmap(mapping, block, &erofs_iomap_ops); 255 } 256 257 static int erofs_prepare_dio(struct kiocb *iocb, struct iov_iter *to) 258 { 259 struct inode *inode = file_inode(iocb->ki_filp); 260 loff_t align = iocb->ki_pos | iov_iter_count(to) | 261 iov_iter_alignment(to); 262 struct block_device *bdev = inode->i_sb->s_bdev; 263 unsigned int blksize_mask; 264 265 if (bdev) 266 blksize_mask = (1 << ilog2(bdev_logical_block_size(bdev))) - 1; 267 else 268 blksize_mask = (1 << inode->i_blkbits) - 1; 269 270 if (align & blksize_mask) 271 return -EINVAL; 272 return 0; 273 } 274 275 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 276 { 277 /* no need taking (shared) inode lock since it's a ro filesystem */ 278 if (!iov_iter_count(to)) 279 return 0; 280 281 #ifdef CONFIG_FS_DAX 282 if (IS_DAX(iocb->ki_filp->f_mapping->host)) 283 return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 284 #endif 285 if (iocb->ki_flags & IOCB_DIRECT) { 286 int err = erofs_prepare_dio(iocb, to); 287 288 if (!err) 289 return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 290 NULL, 0); 291 if (err < 0) 292 return err; 293 } 294 return filemap_read(iocb, to, 0); 295 } 296 297 /* for uncompressed (aligned) files and raw access for other files */ 298 const struct address_space_operations erofs_raw_access_aops = { 299 .readpage = erofs_readpage, 300 .readahead = erofs_readahead, 301 .bmap = erofs_bmap, 302 .direct_IO = noop_direct_IO, 303 }; 304 305 #ifdef CONFIG_FS_DAX 306 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 307 enum page_entry_size pe_size) 308 { 309 return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops); 310 } 311 312 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 313 { 314 return erofs_dax_huge_fault(vmf, PE_SIZE_PTE); 315 } 316 317 static const struct vm_operations_struct erofs_dax_vm_ops = { 318 .fault = erofs_dax_fault, 319 .huge_fault = erofs_dax_huge_fault, 320 }; 321 322 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 323 { 324 if (!IS_DAX(file_inode(file))) 325 return generic_file_readonly_mmap(file, vma); 326 327 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 328 return -EINVAL; 329 330 vma->vm_ops = &erofs_dax_vm_ops; 331 vma->vm_flags |= VM_HUGEPAGE; 332 return 0; 333 } 334 #else 335 #define erofs_file_mmap generic_file_readonly_mmap 336 #endif 337 338 const struct file_operations erofs_file_fops = { 339 .llseek = generic_file_llseek, 340 .read_iter = erofs_file_read_iter, 341 .mmap = erofs_file_mmap, 342 .splice_read = generic_file_splice_read, 343 }; 344