diff options
Diffstat (limited to 'fs/erofs/data.c')
| -rw-r--r-- | fs/erofs/data.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c new file mode 100644 index 000000000..0c2c99c58 --- /dev/null +++ b/fs/erofs/data.c @@ -0,0 +1,452 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2018 HUAWEI, Inc. + * https://www.huawei.com/ + * Copyright (C) 2021, Alibaba Cloud + */ +#include "internal.h" +#include <linux/prefetch.h> +#include <linux/sched/mm.h> +#include <linux/dax.h> +#include <trace/events/erofs.h> + +void erofs_unmap_metabuf(struct erofs_buf *buf) +{ + if (buf->kmap_type == EROFS_KMAP) + kunmap_local(buf->base); + buf->base = NULL; + buf->kmap_type = EROFS_NO_KMAP; +} + +void erofs_put_metabuf(struct erofs_buf *buf) +{ + if (!buf->page) + return; + erofs_unmap_metabuf(buf); + put_page(buf->page); + buf->page = NULL; +} + +/* + * Derive the block size from inode->i_blkbits to make compatible with + * anonymous inode in fscache mode. + */ +void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr, + enum erofs_kmap_type type) +{ + struct inode *inode = buf->inode; + erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits; + pgoff_t index = offset >> PAGE_SHIFT; + struct page *page = buf->page; + struct folio *folio; + unsigned int nofs_flag; + + if (!page || page->index != index) { + erofs_put_metabuf(buf); + + nofs_flag = memalloc_nofs_save(); + folio = read_cache_folio(inode->i_mapping, index, NULL, NULL); + memalloc_nofs_restore(nofs_flag); + if (IS_ERR(folio)) + return folio; + + /* should already be PageUptodate, no need to lock page */ + page = folio_file_page(folio, index); + buf->page = page; + } + if (buf->kmap_type == EROFS_NO_KMAP) { + if (type == EROFS_KMAP) + buf->base = kmap_local_page(page); + buf->kmap_type = type; + } else if (buf->kmap_type != type) { + DBG_BUGON(1); + return ERR_PTR(-EFAULT); + } + if (type == EROFS_NO_KMAP) + return NULL; + return buf->base + (offset & ~PAGE_MASK); +} + +void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb) +{ + if (erofs_is_fscache_mode(sb)) + buf->inode = EROFS_SB(sb)->s_fscache->inode; + else + buf->inode = sb->s_bdev->bd_inode; +} + +void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, + erofs_blk_t blkaddr, enum erofs_kmap_type type) +{ + erofs_init_metabuf(buf, sb); + return erofs_bread(buf, blkaddr, type); +} + +static int erofs_map_blocks_flatmode(struct inode *inode, + struct erofs_map_blocks *map) +{ + erofs_blk_t nblocks, lastblk; + u64 offset = map->m_la; + struct erofs_inode *vi = EROFS_I(inode); + struct super_block *sb = inode->i_sb; + bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); + + nblocks = erofs_iblks(inode); + lastblk = nblocks - tailendpacking; + + /* there is no hole in flatmode */ + map->m_flags = EROFS_MAP_MAPPED; + if (offset < erofs_pos(sb, lastblk)) { + map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la; + map->m_plen = erofs_pos(sb, lastblk) - offset; + } else if (tailendpacking) { + map->m_pa = erofs_iloc(inode) + vi->inode_isize + + vi->xattr_isize + erofs_blkoff(sb, offset); + map->m_plen = inode->i_size - offset; + + /* inline data should be located in the same meta block */ + if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { + erofs_err(sb, "inline data cross block boundary @ nid %llu", + vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } + map->m_flags |= EROFS_MAP_META; + } else { + erofs_err(sb, "internal error @ nid: %llu (size %llu), m_la 0x%llx", + vi->nid, inode->i_size, map->m_la); + DBG_BUGON(1); + return -EIO; + } + return 0; +} + +int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) +{ + struct super_block *sb = inode->i_sb; + struct erofs_inode *vi = EROFS_I(inode); + struct erofs_inode_chunk_index *idx; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + u64 chunknr; + unsigned int unit; + erofs_off_t pos; + void *kaddr; + int err = 0; + + trace_erofs_map_blocks_enter(inode, map, 0); + map->m_deviceid = 0; + if (map->m_la >= inode->i_size) { + /* leave out-of-bound access unmapped */ + map->m_flags = 0; + map->m_plen = 0; + goto out; + } + + if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { + err = erofs_map_blocks_flatmode(inode, map); + goto out; + } + + if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) + unit = sizeof(*idx); /* chunk index */ + else + unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */ + + chunknr = map->m_la >> vi->chunkbits; + pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + + vi->xattr_isize, unit) + unit * chunknr; + + kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(sb, pos), EROFS_KMAP); + if (IS_ERR(kaddr)) { + err = PTR_ERR(kaddr); + goto out; + } + map->m_la = chunknr << vi->chunkbits; + map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits, + round_up(inode->i_size - map->m_la, sb->s_blocksize)); + + /* handle block map */ + if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) { + __le32 *blkaddr = kaddr + erofs_blkoff(sb, pos); + + if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) { + map->m_flags = 0; + } else { + map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr)); + map->m_flags = EROFS_MAP_MAPPED; + } + goto out_unlock; + } + /* parse chunk indexes */ + idx = kaddr + erofs_blkoff(sb, pos); + switch (le32_to_cpu(idx->blkaddr)) { + case EROFS_NULL_ADDR: + map->m_flags = 0; + break; + default: + map->m_deviceid = le16_to_cpu(idx->device_id) & + EROFS_SB(sb)->device_id_mask; + map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr)); + map->m_flags = EROFS_MAP_MAPPED; + break; + } +out_unlock: + erofs_put_metabuf(&buf); +out: + if (!err) + map->m_llen = map->m_plen; + trace_erofs_map_blocks_exit(inode, map, 0, err); + return err; +} + +int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) +{ + struct erofs_dev_context *devs = EROFS_SB(sb)->devs; + struct erofs_device_info *dif; + int id; + + map->m_bdev = sb->s_bdev; + map->m_daxdev = EROFS_SB(sb)->dax_dev; + map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; + map->m_fscache = EROFS_SB(sb)->s_fscache; + + if (map->m_deviceid) { + down_read(&devs->rwsem); + dif = idr_find(&devs->tree, map->m_deviceid - 1); + if (!dif) { + up_read(&devs->rwsem); + return -ENODEV; + } + if (devs->flatdev) { + map->m_pa += erofs_pos(sb, dif->mapped_blkaddr); + up_read(&devs->rwsem); + return 0; + } + map->m_bdev = dif->bdev; + map->m_daxdev = dif->dax_dev; + map->m_dax_part_off = dif->dax_part_off; + map->m_fscache = dif->fscache; + up_read(&devs->rwsem); + } else if (devs->extra_devices && !devs->flatdev) { + down_read(&devs->rwsem); + idr_for_each_entry(&devs->tree, dif, id) { + erofs_off_t startoff, length; + + if (!dif->mapped_blkaddr) + continue; + startoff = erofs_pos(sb, dif->mapped_blkaddr); + length = erofs_pos(sb, dif->blocks); + + if (map->m_pa >= startoff && + map->m_pa < startoff + length) { + map->m_pa -= startoff; + map->m_bdev = dif->bdev; + map->m_daxdev = dif->dax_dev; + map->m_dax_part_off = dif->dax_part_off; + map->m_fscache = dif->fscache; + break; + } + } + up_read(&devs->rwsem); + } + return 0; +} + +static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) +{ + int ret; + struct super_block *sb = inode->i_sb; + struct erofs_map_blocks map; + struct erofs_map_dev mdev; + + map.m_la = offset; + map.m_llen = length; + + ret = erofs_map_blocks(inode, &map); + if (ret < 0) + return ret; + + mdev = (struct erofs_map_dev) { + .m_deviceid = map.m_deviceid, + .m_pa = map.m_pa, + }; + ret = erofs_map_dev(sb, &mdev); + if (ret) + return ret; + + iomap->offset = map.m_la; + if (flags & IOMAP_DAX) + iomap->dax_dev = mdev.m_daxdev; + else + iomap->bdev = mdev.m_bdev; + iomap->length = map.m_llen; + iomap->flags = 0; + iomap->private = NULL; + + if (!(map.m_flags & EROFS_MAP_MAPPED)) { + iomap->type = IOMAP_HOLE; + iomap->addr = IOMAP_NULL_ADDR; + if (!iomap->length) + iomap->length = length; + return 0; + } + + if (map.m_flags & EROFS_MAP_META) { + void *ptr; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + + iomap->type = IOMAP_INLINE; + ptr = erofs_read_metabuf(&buf, sb, + erofs_blknr(sb, mdev.m_pa), EROFS_KMAP); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + iomap->inline_data = ptr + erofs_blkoff(sb, mdev.m_pa); + iomap->private = buf.base; + } else { + iomap->type = IOMAP_MAPPED; + iomap->addr = mdev.m_pa; + if (flags & IOMAP_DAX) + iomap->addr += mdev.m_dax_part_off; + } + return 0; +} + +static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned int flags, struct iomap *iomap) +{ + void *ptr = iomap->private; + + if (ptr) { + struct erofs_buf buf = { + .page = kmap_to_page(ptr), + .base = ptr, + .kmap_type = EROFS_KMAP, + }; + + DBG_BUGON(iomap->type != IOMAP_INLINE); + erofs_put_metabuf(&buf); + } else { + DBG_BUGON(iomap->type == IOMAP_INLINE); + } + return written; +} + +static const struct iomap_ops erofs_iomap_ops = { + .iomap_begin = erofs_iomap_begin, + .iomap_end = erofs_iomap_end, +}; + +int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + u64 start, u64 len) +{ + if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { +#ifdef CONFIG_EROFS_FS_ZIP + return iomap_fiemap(inode, fieinfo, start, len, + &z_erofs_iomap_report_ops); +#else + return -EOPNOTSUPP; +#endif + } + return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops); +} + +/* + * since we dont have write or truncate flows, so no inode + * locking needs to be held at the moment. + */ +static int erofs_read_folio(struct file *file, struct folio *folio) +{ + return iomap_read_folio(folio, &erofs_iomap_ops); +} + +static void erofs_readahead(struct readahead_control *rac) +{ + return iomap_readahead(rac, &erofs_iomap_ops); +} + +static sector_t erofs_bmap(struct address_space *mapping, sector_t block) +{ + return iomap_bmap(mapping, block, &erofs_iomap_ops); +} + +static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + /* no need taking (shared) inode lock since it's a ro filesystem */ + if (!iov_iter_count(to)) + return 0; + +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + return dax_iomap_rw(iocb, to, &erofs_iomap_ops); +#endif + if (iocb->ki_flags & IOCB_DIRECT) { + struct block_device *bdev = inode->i_sb->s_bdev; + unsigned int blksize_mask; + + if (bdev) + blksize_mask = bdev_logical_block_size(bdev) - 1; + else + blksize_mask = i_blocksize(inode) - 1; + + if ((iocb->ki_pos | iov_iter_count(to) | + iov_iter_alignment(to)) & blksize_mask) + return -EINVAL; + + return iomap_dio_rw(iocb, to, &erofs_iomap_ops, + NULL, 0, NULL, 0); + } + return filemap_read(iocb, to, 0); +} + +/* for uncompressed (aligned) files and raw access for other files */ +const struct address_space_operations erofs_raw_access_aops = { + .read_folio = erofs_read_folio, + .readahead = erofs_readahead, + .bmap = erofs_bmap, + .direct_IO = noop_direct_IO, + .release_folio = iomap_release_folio, + .invalidate_folio = iomap_invalidate_folio, +}; + +#ifdef CONFIG_FS_DAX +static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf, + unsigned int order) +{ + return dax_iomap_fault(vmf, order, NULL, NULL, &erofs_iomap_ops); +} + +static vm_fault_t erofs_dax_fault(struct vm_fault *vmf) +{ + return erofs_dax_huge_fault(vmf, 0); +} + +static const struct vm_operations_struct erofs_dax_vm_ops = { + .fault = erofs_dax_fault, + .huge_fault = erofs_dax_huge_fault, +}; + +static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + if (!IS_DAX(file_inode(file))) + return generic_file_readonly_mmap(file, vma); + + if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) + return -EINVAL; + + vma->vm_ops = &erofs_dax_vm_ops; + vm_flags_set(vma, VM_HUGEPAGE); + return 0; +} +#else +#define erofs_file_mmap generic_file_readonly_mmap +#endif + +const struct file_operations erofs_file_fops = { + .llseek = generic_file_llseek, + .read_iter = erofs_file_read_iter, + .mmap = erofs_file_mmap, + .splice_read = filemap_splice_read, +}; |