147e4937aSGao Xiang // SPDX-License-Identifier: GPL-2.0-only 247e4937aSGao Xiang /* 347e4937aSGao Xiang * Copyright (C) 2017-2018 HUAWEI, Inc. 4592e7cd0SAlexander A. Klimov * https://www.huawei.com/ 5c5aa903aSGao Xiang * Copyright (C) 2021, Alibaba Cloud 647e4937aSGao Xiang */ 747e4937aSGao Xiang #include "internal.h" 847e4937aSGao Xiang #include <linux/prefetch.h> 95375e7c8SJeffle Xu #include <linux/sched/mm.h> 1006252e9cSGao Xiang #include <linux/dax.h> 1147e4937aSGao Xiang #include <trace/events/erofs.h> 1247e4937aSGao Xiang 13fdf80a47SGao Xiang void erofs_unmap_metabuf(struct erofs_buf *buf) 14fdf80a47SGao Xiang { 15fdf80a47SGao Xiang if (buf->kmap_type == EROFS_KMAP) 16927e5010SGao Xiang kunmap_local(buf->base); 17fdf80a47SGao Xiang buf->base = NULL; 18fdf80a47SGao Xiang buf->kmap_type = EROFS_NO_KMAP; 19fdf80a47SGao Xiang } 20fdf80a47SGao Xiang 21fdf80a47SGao Xiang void erofs_put_metabuf(struct erofs_buf *buf) 22fdf80a47SGao Xiang { 23fdf80a47SGao Xiang if (!buf->page) 24fdf80a47SGao Xiang return; 25fdf80a47SGao Xiang erofs_unmap_metabuf(buf); 26fdf80a47SGao Xiang put_page(buf->page); 27fdf80a47SGao Xiang buf->page = NULL; 28fdf80a47SGao Xiang } 29fdf80a47SGao Xiang 30*3acea5fcSJingbo Xu /* 31*3acea5fcSJingbo Xu * Derive the block size from inode->i_blkbits to make compatible with 32*3acea5fcSJingbo Xu * anonymous inode in fscache mode. 33*3acea5fcSJingbo Xu */ 34fe5de585SGao Xiang void *erofs_bread(struct erofs_buf *buf, struct inode *inode, 35fdf80a47SGao Xiang erofs_blk_t blkaddr, enum erofs_kmap_type type) 36fdf80a47SGao Xiang { 37*3acea5fcSJingbo Xu erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits; 38fe5de585SGao Xiang struct address_space *const mapping = inode->i_mapping; 39fdf80a47SGao Xiang pgoff_t index = offset >> PAGE_SHIFT; 40fdf80a47SGao Xiang struct page *page = buf->page; 415375e7c8SJeffle Xu struct folio *folio; 425375e7c8SJeffle Xu unsigned int nofs_flag; 43fdf80a47SGao Xiang 44fdf80a47SGao Xiang if (!page || page->index != index) { 45fdf80a47SGao Xiang erofs_put_metabuf(buf); 465375e7c8SJeffle Xu 475375e7c8SJeffle Xu nofs_flag = memalloc_nofs_save(); 485375e7c8SJeffle Xu folio = read_cache_folio(mapping, index, NULL, NULL); 495375e7c8SJeffle Xu memalloc_nofs_restore(nofs_flag); 505375e7c8SJeffle Xu if (IS_ERR(folio)) 515375e7c8SJeffle Xu return folio; 525375e7c8SJeffle Xu 53fdf80a47SGao Xiang /* should already be PageUptodate, no need to lock page */ 545375e7c8SJeffle Xu page = folio_file_page(folio, index); 55fdf80a47SGao Xiang buf->page = page; 56fdf80a47SGao Xiang } 57fdf80a47SGao Xiang if (buf->kmap_type == EROFS_NO_KMAP) { 58fdf80a47SGao Xiang if (type == EROFS_KMAP) 59927e5010SGao Xiang buf->base = kmap_local_page(page); 60fdf80a47SGao Xiang buf->kmap_type = type; 61fdf80a47SGao Xiang } else if (buf->kmap_type != type) { 62fdf80a47SGao Xiang DBG_BUGON(1); 63fdf80a47SGao Xiang return ERR_PTR(-EFAULT); 64fdf80a47SGao Xiang } 65fdf80a47SGao Xiang if (type == EROFS_NO_KMAP) 66fdf80a47SGao Xiang return NULL; 67fdf80a47SGao Xiang return buf->base + (offset & ~PAGE_MASK); 68fdf80a47SGao Xiang } 69fdf80a47SGao Xiang 70fe5de585SGao Xiang void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, 71fe5de585SGao Xiang erofs_blk_t blkaddr, enum erofs_kmap_type type) 72fe5de585SGao Xiang { 735375e7c8SJeffle Xu if (erofs_is_fscache_mode(sb)) 745375e7c8SJeffle Xu return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode, 755375e7c8SJeffle Xu blkaddr, type); 765375e7c8SJeffle Xu 77fe5de585SGao Xiang return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type); 78fe5de585SGao Xiang } 79fe5de585SGao Xiang 8047e4937aSGao Xiang static int erofs_map_blocks_flatmode(struct inode *inode, 818b58f9f0SJingbo Xu struct erofs_map_blocks *map) 8247e4937aSGao Xiang { 8347e4937aSGao Xiang erofs_blk_t nblocks, lastblk; 8447e4937aSGao Xiang u64 offset = map->m_la; 85a5876e24SGao Xiang struct erofs_inode *vi = EROFS_I(inode); 86*3acea5fcSJingbo Xu struct super_block *sb = inode->i_sb; 878a765682SGao Xiang bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); 8847e4937aSGao Xiang 89*3acea5fcSJingbo Xu nblocks = erofs_iblks(inode); 908a765682SGao Xiang lastblk = nblocks - tailendpacking; 9147e4937aSGao Xiang 9247e4937aSGao Xiang /* there is no hole in flatmode */ 9347e4937aSGao Xiang map->m_flags = EROFS_MAP_MAPPED; 94*3acea5fcSJingbo Xu if (offset < erofs_pos(sb, lastblk)) { 95*3acea5fcSJingbo Xu map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la; 96*3acea5fcSJingbo Xu map->m_plen = erofs_pos(sb, lastblk) - offset; 978a765682SGao Xiang } else if (tailendpacking) { 98b780d3fcSGao Xiang map->m_pa = erofs_iloc(inode) + vi->inode_isize + 99*3acea5fcSJingbo Xu vi->xattr_isize + erofs_blkoff(sb, offset); 10047e4937aSGao Xiang map->m_plen = inode->i_size - offset; 10147e4937aSGao Xiang 102469407a3SGao Xiang /* inline data should be located in the same meta block */ 103*3acea5fcSJingbo Xu if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { 104*3acea5fcSJingbo Xu erofs_err(sb, "inline data cross block boundary @ nid %llu", 10547e4937aSGao Xiang vi->nid); 10647e4937aSGao Xiang DBG_BUGON(1); 107469407a3SGao Xiang return -EFSCORRUPTED; 10847e4937aSGao Xiang } 10947e4937aSGao Xiang map->m_flags |= EROFS_MAP_META; 11047e4937aSGao Xiang } else { 111*3acea5fcSJingbo Xu erofs_err(sb, "internal error @ nid: %llu (size %llu), m_la 0x%llx", 11247e4937aSGao Xiang vi->nid, inode->i_size, map->m_la); 11347e4937aSGao Xiang DBG_BUGON(1); 114469407a3SGao Xiang return -EIO; 11547e4937aSGao Xiang } 116469407a3SGao Xiang return 0; 11747e4937aSGao Xiang } 11847e4937aSGao Xiang 1198b58f9f0SJingbo Xu int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) 120c5aa903aSGao Xiang { 121c5aa903aSGao Xiang struct super_block *sb = inode->i_sb; 122c5aa903aSGao Xiang struct erofs_inode *vi = EROFS_I(inode); 123c5aa903aSGao Xiang struct erofs_inode_chunk_index *idx; 124fdf80a47SGao Xiang struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 125c5aa903aSGao Xiang u64 chunknr; 126c5aa903aSGao Xiang unsigned int unit; 127c5aa903aSGao Xiang erofs_off_t pos; 128fdf80a47SGao Xiang void *kaddr; 129c5aa903aSGao Xiang int err = 0; 130c5aa903aSGao Xiang 1318b58f9f0SJingbo Xu trace_erofs_map_blocks_enter(inode, map, 0); 132dfeab2e9SGao Xiang map->m_deviceid = 0; 133c5aa903aSGao Xiang if (map->m_la >= inode->i_size) { 134c5aa903aSGao Xiang /* leave out-of-bound access unmapped */ 135c5aa903aSGao Xiang map->m_flags = 0; 136c5aa903aSGao Xiang map->m_plen = 0; 137c5aa903aSGao Xiang goto out; 138c5aa903aSGao Xiang } 139c5aa903aSGao Xiang 140469407a3SGao Xiang if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { 1418b58f9f0SJingbo Xu err = erofs_map_blocks_flatmode(inode, map); 142469407a3SGao Xiang goto out; 143469407a3SGao Xiang } 144c5aa903aSGao Xiang 145c5aa903aSGao Xiang if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) 146c5aa903aSGao Xiang unit = sizeof(*idx); /* chunk index */ 147c5aa903aSGao Xiang else 148c5aa903aSGao Xiang unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ 149c5aa903aSGao Xiang 150c5aa903aSGao Xiang chunknr = map->m_la >> vi->chunkbits; 151b780d3fcSGao Xiang pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + 152c5aa903aSGao Xiang vi->xattr_isize, unit) + unit * chunknr; 153c5aa903aSGao Xiang 154*3acea5fcSJingbo Xu kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(sb, pos), EROFS_KMAP); 155fdf80a47SGao Xiang if (IS_ERR(kaddr)) { 156fdf80a47SGao Xiang err = PTR_ERR(kaddr); 157469407a3SGao Xiang goto out; 158469407a3SGao Xiang } 159c5aa903aSGao Xiang map->m_la = chunknr << vi->chunkbits; 160c5aa903aSGao Xiang map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, 161*3acea5fcSJingbo Xu round_up(inode->i_size - map->m_la, sb->s_blocksize)); 162c5aa903aSGao Xiang 163c5aa903aSGao Xiang /* handle block map */ 164c5aa903aSGao Xiang if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { 165*3acea5fcSJingbo Xu __le32 *blkaddr = kaddr + erofs_blkoff(sb, pos); 166c5aa903aSGao Xiang 167c5aa903aSGao Xiang if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { 168c5aa903aSGao Xiang map->m_flags = 0; 169c5aa903aSGao Xiang } else { 170*3acea5fcSJingbo Xu map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr)); 171c5aa903aSGao Xiang map->m_flags = EROFS_MAP_MAPPED; 172c5aa903aSGao Xiang } 173c5aa903aSGao Xiang goto out_unlock; 174c5aa903aSGao Xiang } 175c5aa903aSGao Xiang /* parse chunk indexes */ 176*3acea5fcSJingbo Xu idx = kaddr + erofs_blkoff(sb, pos); 177c5aa903aSGao Xiang switch (le32_to_cpu(idx->blkaddr)) { 178c5aa903aSGao Xiang case EROFS_NULL_ADDR: 179c5aa903aSGao Xiang map->m_flags = 0; 180c5aa903aSGao Xiang break; 181c5aa903aSGao Xiang default: 182dfeab2e9SGao Xiang map->m_deviceid = le16_to_cpu(idx->device_id) & 183dfeab2e9SGao Xiang EROFS_SB(sb)->device_id_mask; 184*3acea5fcSJingbo Xu map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr)); 185c5aa903aSGao Xiang map->m_flags = EROFS_MAP_MAPPED; 186c5aa903aSGao Xiang break; 187c5aa903aSGao Xiang } 188c5aa903aSGao Xiang out_unlock: 189fdf80a47SGao Xiang erofs_put_metabuf(&buf); 190c5aa903aSGao Xiang out: 191469407a3SGao Xiang if (!err) 192c5aa903aSGao Xiang map->m_llen = map->m_plen; 1938b58f9f0SJingbo Xu trace_erofs_map_blocks_exit(inode, map, 0, err); 194c5aa903aSGao Xiang return err; 195c5aa903aSGao Xiang } 196c5aa903aSGao Xiang 197dfeab2e9SGao Xiang int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) 198dfeab2e9SGao Xiang { 199dfeab2e9SGao Xiang struct erofs_dev_context *devs = EROFS_SB(sb)->devs; 200dfeab2e9SGao Xiang struct erofs_device_info *dif; 201dfeab2e9SGao Xiang int id; 202dfeab2e9SGao Xiang 203dfeab2e9SGao Xiang /* primary device by default */ 204dfeab2e9SGao Xiang map->m_bdev = sb->s_bdev; 205dfeab2e9SGao Xiang map->m_daxdev = EROFS_SB(sb)->dax_dev; 206de205114SChristoph Hellwig map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; 207955b478eSJeffle Xu map->m_fscache = EROFS_SB(sb)->s_fscache; 208dfeab2e9SGao Xiang 209dfeab2e9SGao Xiang if (map->m_deviceid) { 210dfeab2e9SGao Xiang down_read(&devs->rwsem); 211dfeab2e9SGao Xiang dif = idr_find(&devs->tree, map->m_deviceid - 1); 212dfeab2e9SGao Xiang if (!dif) { 213dfeab2e9SGao Xiang up_read(&devs->rwsem); 214dfeab2e9SGao Xiang return -ENODEV; 215dfeab2e9SGao Xiang } 216dfeab2e9SGao Xiang map->m_bdev = dif->bdev; 217dfeab2e9SGao Xiang map->m_daxdev = dif->dax_dev; 218de205114SChristoph Hellwig map->m_dax_part_off = dif->dax_part_off; 219955b478eSJeffle Xu map->m_fscache = dif->fscache; 220dfeab2e9SGao Xiang up_read(&devs->rwsem); 221dfeab2e9SGao Xiang } else if (devs->extra_devices) { 222dfeab2e9SGao Xiang down_read(&devs->rwsem); 223dfeab2e9SGao Xiang idr_for_each_entry(&devs->tree, dif, id) { 224dfeab2e9SGao Xiang erofs_off_t startoff, length; 225dfeab2e9SGao Xiang 226dfeab2e9SGao Xiang if (!dif->mapped_blkaddr) 227dfeab2e9SGao Xiang continue; 228*3acea5fcSJingbo Xu startoff = erofs_pos(sb, dif->mapped_blkaddr); 229*3acea5fcSJingbo Xu length = erofs_pos(sb, dif->blocks); 230dfeab2e9SGao Xiang 231dfeab2e9SGao Xiang if (map->m_pa >= startoff && 232dfeab2e9SGao Xiang map->m_pa < startoff + length) { 233dfeab2e9SGao Xiang map->m_pa -= startoff; 234dfeab2e9SGao Xiang map->m_bdev = dif->bdev; 235dfeab2e9SGao Xiang map->m_daxdev = dif->dax_dev; 236de205114SChristoph Hellwig map->m_dax_part_off = dif->dax_part_off; 237955b478eSJeffle Xu map->m_fscache = dif->fscache; 238dfeab2e9SGao Xiang break; 239dfeab2e9SGao Xiang } 240dfeab2e9SGao Xiang } 241dfeab2e9SGao Xiang up_read(&devs->rwsem); 242dfeab2e9SGao Xiang } 243dfeab2e9SGao Xiang return 0; 244dfeab2e9SGao Xiang } 245dfeab2e9SGao Xiang 246a08e67a0SHuang Jianan static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 247a08e67a0SHuang Jianan unsigned int flags, struct iomap *iomap, struct iomap *srcmap) 248a08e67a0SHuang Jianan { 249a08e67a0SHuang Jianan int ret; 250*3acea5fcSJingbo Xu struct super_block *sb = inode->i_sb; 251a08e67a0SHuang Jianan struct erofs_map_blocks map; 252dfeab2e9SGao Xiang struct erofs_map_dev mdev; 253a08e67a0SHuang Jianan 254a08e67a0SHuang Jianan map.m_la = offset; 255a08e67a0SHuang Jianan map.m_llen = length; 256a08e67a0SHuang Jianan 2578b58f9f0SJingbo Xu ret = erofs_map_blocks(inode, &map); 258a08e67a0SHuang Jianan if (ret < 0) 259a08e67a0SHuang Jianan return ret; 260a08e67a0SHuang Jianan 261dfeab2e9SGao Xiang mdev = (struct erofs_map_dev) { 262dfeab2e9SGao Xiang .m_deviceid = map.m_deviceid, 263dfeab2e9SGao Xiang .m_pa = map.m_pa, 264dfeab2e9SGao Xiang }; 265*3acea5fcSJingbo Xu ret = erofs_map_dev(sb, &mdev); 266dfeab2e9SGao Xiang if (ret) 267dfeab2e9SGao Xiang return ret; 268dfeab2e9SGao Xiang 269a08e67a0SHuang Jianan iomap->offset = map.m_la; 270e33f42b2SGao Xiang if (flags & IOMAP_DAX) 271de205114SChristoph Hellwig iomap->dax_dev = mdev.m_daxdev; 272e33f42b2SGao Xiang else 273de205114SChristoph Hellwig iomap->bdev = mdev.m_bdev; 274a08e67a0SHuang Jianan iomap->length = map.m_llen; 275a08e67a0SHuang Jianan iomap->flags = 0; 276771c994eSGao Xiang iomap->private = NULL; 277a08e67a0SHuang Jianan 278a08e67a0SHuang Jianan if (!(map.m_flags & EROFS_MAP_MAPPED)) { 279a08e67a0SHuang Jianan iomap->type = IOMAP_HOLE; 280a08e67a0SHuang Jianan iomap->addr = IOMAP_NULL_ADDR; 281a08e67a0SHuang Jianan if (!iomap->length) 282a08e67a0SHuang Jianan iomap->length = length; 283a08e67a0SHuang Jianan return 0; 284a08e67a0SHuang Jianan } 285a08e67a0SHuang Jianan 286a08e67a0SHuang Jianan if (map.m_flags & EROFS_MAP_META) { 287fdf80a47SGao Xiang void *ptr; 288fdf80a47SGao Xiang struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 289771c994eSGao Xiang 290771c994eSGao Xiang iomap->type = IOMAP_INLINE; 291*3acea5fcSJingbo Xu ptr = erofs_read_metabuf(&buf, sb, 292*3acea5fcSJingbo Xu erofs_blknr(sb, mdev.m_pa), EROFS_KMAP); 293fdf80a47SGao Xiang if (IS_ERR(ptr)) 294fdf80a47SGao Xiang return PTR_ERR(ptr); 295*3acea5fcSJingbo Xu iomap->inline_data = ptr + erofs_blkoff(sb, mdev.m_pa); 296fdf80a47SGao Xiang iomap->private = buf.base; 297771c994eSGao Xiang } else { 298a08e67a0SHuang Jianan iomap->type = IOMAP_MAPPED; 299dfeab2e9SGao Xiang iomap->addr = mdev.m_pa; 300e33f42b2SGao Xiang if (flags & IOMAP_DAX) 301e33f42b2SGao Xiang iomap->addr += mdev.m_dax_part_off; 302771c994eSGao Xiang } 303a08e67a0SHuang Jianan return 0; 304a08e67a0SHuang Jianan } 305a08e67a0SHuang Jianan 306771c994eSGao Xiang static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, 307771c994eSGao Xiang ssize_t written, unsigned int flags, struct iomap *iomap) 308771c994eSGao Xiang { 309fdf80a47SGao Xiang void *ptr = iomap->private; 310771c994eSGao Xiang 311fdf80a47SGao Xiang if (ptr) { 312fdf80a47SGao Xiang struct erofs_buf buf = { 313fdf80a47SGao Xiang .page = kmap_to_page(ptr), 314fdf80a47SGao Xiang .base = ptr, 315fdf80a47SGao Xiang .kmap_type = EROFS_KMAP, 316fdf80a47SGao Xiang }; 317fdf80a47SGao Xiang 318771c994eSGao Xiang DBG_BUGON(iomap->type != IOMAP_INLINE); 319fdf80a47SGao Xiang erofs_put_metabuf(&buf); 320771c994eSGao Xiang } else { 321771c994eSGao Xiang DBG_BUGON(iomap->type == IOMAP_INLINE); 322771c994eSGao Xiang } 323771c994eSGao Xiang return written; 324771c994eSGao Xiang } 325771c994eSGao Xiang 326a08e67a0SHuang Jianan static const struct iomap_ops erofs_iomap_ops = { 327a08e67a0SHuang Jianan .iomap_begin = erofs_iomap_begin, 328771c994eSGao Xiang .iomap_end = erofs_iomap_end, 329a08e67a0SHuang Jianan }; 330a08e67a0SHuang Jianan 331eadcd6b5SGao Xiang int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 332eadcd6b5SGao Xiang u64 start, u64 len) 333eadcd6b5SGao Xiang { 334eadcd6b5SGao Xiang if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { 335eadcd6b5SGao Xiang #ifdef CONFIG_EROFS_FS_ZIP 336eadcd6b5SGao Xiang return iomap_fiemap(inode, fieinfo, start, len, 337eadcd6b5SGao Xiang &z_erofs_iomap_report_ops); 338eadcd6b5SGao Xiang #else 339eadcd6b5SGao Xiang return -EOPNOTSUPP; 340eadcd6b5SGao Xiang #endif 341eadcd6b5SGao Xiang } 342eadcd6b5SGao Xiang return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); 343eadcd6b5SGao Xiang } 344eadcd6b5SGao Xiang 345771c994eSGao Xiang /* 346771c994eSGao Xiang * since we dont have write or truncate flows, so no inode 347771c994eSGao Xiang * locking needs to be held at the moment. 348771c994eSGao Xiang */ 3497479c505SMatthew Wilcox (Oracle) static int erofs_read_folio(struct file *file, struct folio *folio) 350771c994eSGao Xiang { 3517479c505SMatthew Wilcox (Oracle) return iomap_read_folio(folio, &erofs_iomap_ops); 352771c994eSGao Xiang } 353771c994eSGao Xiang 354771c994eSGao Xiang static void erofs_readahead(struct readahead_control *rac) 355771c994eSGao Xiang { 356771c994eSGao Xiang return iomap_readahead(rac, &erofs_iomap_ops); 357771c994eSGao Xiang } 358771c994eSGao Xiang 359771c994eSGao Xiang static sector_t erofs_bmap(struct address_space *mapping, sector_t block) 360771c994eSGao Xiang { 361771c994eSGao Xiang return iomap_bmap(mapping, block, &erofs_iomap_ops); 362771c994eSGao Xiang } 363771c994eSGao Xiang 364a08e67a0SHuang Jianan static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) 365a08e67a0SHuang Jianan { 366de8a801aSGao Xiang struct inode *inode = file_inode(iocb->ki_filp); 367de8a801aSGao Xiang 368a08e67a0SHuang Jianan /* no need taking (shared) inode lock since it's a ro filesystem */ 369a08e67a0SHuang Jianan if (!iov_iter_count(to)) 370a08e67a0SHuang Jianan return 0; 371a08e67a0SHuang Jianan 37206252e9cSGao Xiang #ifdef CONFIG_FS_DAX 373de8a801aSGao Xiang if (IS_DAX(inode)) 37406252e9cSGao Xiang return dax_iomap_rw(iocb, to, &erofs_iomap_ops); 37506252e9cSGao Xiang #endif 376a08e67a0SHuang Jianan if (iocb->ki_flags & IOCB_DIRECT) { 377de8a801aSGao Xiang struct block_device *bdev = inode->i_sb->s_bdev; 378de8a801aSGao Xiang unsigned int blksize_mask; 379a08e67a0SHuang Jianan 380de8a801aSGao Xiang if (bdev) 381de8a801aSGao Xiang blksize_mask = bdev_logical_block_size(bdev) - 1; 382de8a801aSGao Xiang else 3833993f4f4SYue Hu blksize_mask = i_blocksize(inode) - 1; 384de8a801aSGao Xiang 385de8a801aSGao Xiang if ((iocb->ki_pos | iov_iter_count(to) | 386de8a801aSGao Xiang iov_iter_alignment(to)) & blksize_mask) 387de8a801aSGao Xiang return -EINVAL; 388de8a801aSGao Xiang 389a08e67a0SHuang Jianan return iomap_dio_rw(iocb, to, &erofs_iomap_ops, 390786f847fSChristoph Hellwig NULL, 0, NULL, 0); 391a08e67a0SHuang Jianan } 392a08e67a0SHuang Jianan return filemap_read(iocb, to, 0); 393a08e67a0SHuang Jianan } 394a08e67a0SHuang Jianan 39547e4937aSGao Xiang /* for uncompressed (aligned) files and raw access for other files */ 39647e4937aSGao Xiang const struct address_space_operations erofs_raw_access_aops = { 3977479c505SMatthew Wilcox (Oracle) .read_folio = erofs_read_folio, 398771c994eSGao Xiang .readahead = erofs_readahead, 39947e4937aSGao Xiang .bmap = erofs_bmap, 400a08e67a0SHuang Jianan .direct_IO = noop_direct_IO, 401ce529cc2SJingbo Xu .release_folio = iomap_release_folio, 402ce529cc2SJingbo Xu .invalidate_folio = iomap_invalidate_folio, 403a08e67a0SHuang Jianan }; 404a08e67a0SHuang Jianan 40506252e9cSGao Xiang #ifdef CONFIG_FS_DAX 40606252e9cSGao Xiang static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, 40706252e9cSGao Xiang enum page_entry_size pe_size) 40806252e9cSGao Xiang { 40906252e9cSGao Xiang return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops); 41006252e9cSGao Xiang } 41106252e9cSGao Xiang 41206252e9cSGao Xiang static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) 41306252e9cSGao Xiang { 41406252e9cSGao Xiang return erofs_dax_huge_fault(vmf, PE_SIZE_PTE); 41506252e9cSGao Xiang } 41606252e9cSGao Xiang 41706252e9cSGao Xiang static const struct vm_operations_struct erofs_dax_vm_ops = { 41806252e9cSGao Xiang .fault = erofs_dax_fault, 41906252e9cSGao Xiang .huge_fault = erofs_dax_huge_fault, 42006252e9cSGao Xiang }; 42106252e9cSGao Xiang 42206252e9cSGao Xiang static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 42306252e9cSGao Xiang { 42406252e9cSGao Xiang if (!IS_DAX(file_inode(file))) 42506252e9cSGao Xiang return generic_file_readonly_mmap(file, vma); 42606252e9cSGao Xiang 42706252e9cSGao Xiang if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) 42806252e9cSGao Xiang return -EINVAL; 42906252e9cSGao Xiang 43006252e9cSGao Xiang vma->vm_ops = &erofs_dax_vm_ops; 4311c71222eSSuren Baghdasaryan vm_flags_set(vma, VM_HUGEPAGE); 43206252e9cSGao Xiang return 0; 43306252e9cSGao Xiang } 43406252e9cSGao Xiang #else 43506252e9cSGao Xiang #define erofs_file_mmap generic_file_readonly_mmap 43606252e9cSGao Xiang #endif 43706252e9cSGao Xiang 438a08e67a0SHuang Jianan const struct file_operations erofs_file_fops = { 439a08e67a0SHuang Jianan .llseek = generic_file_llseek, 440a08e67a0SHuang Jianan .read_iter = erofs_file_read_iter, 44106252e9cSGao Xiang .mmap = erofs_file_mmap, 442a08e67a0SHuang Jianan .splice_read = generic_file_splice_read, 44347e4937aSGao Xiang }; 444