diff options
Diffstat (limited to 'fs/erofs/data.c')
| -rw-r--r-- | fs/erofs/data.c | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c new file mode 100644 index 000000000..0885b1f2f --- /dev/null +++ b/fs/erofs/data.c @@ -0,0 +1,534 @@ +// 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/filelock.h> +#include <linux/sched/mm.h> +#include <trace/events/erofs.h> + +void erofs_unmap_metabuf(struct erofs_buf *buf) +{ + if (!buf->base) + return; + kunmap_local(buf->base); + buf->base = NULL; +} + +void erofs_put_metabuf(struct erofs_buf *buf) +{ + if (!buf->page) + return; + erofs_unmap_metabuf(buf); + folio_put(page_folio(buf->page)); + buf->page = NULL; +} + +void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset, bool need_kmap) +{ + pgoff_t index = (buf->off + offset) >> PAGE_SHIFT; + struct folio *folio = NULL; + + if (buf->page) { + folio = page_folio(buf->page); + if (folio_file_page(folio, index) != buf->page) + erofs_unmap_metabuf(buf); + } + if (!folio || !folio_contains(folio, index)) { + erofs_put_metabuf(buf); + folio = read_cache_folio(buf->mapping, index, + buf->mc ? erofs_read_meta_folio : NULL, NULL); + if (IS_ERR(folio)) + return folio; + } + buf->page = folio_file_page(folio, index); + if (!need_kmap) + return NULL; + if (!buf->base) + buf->base = kmap_local_page(buf->page); + return buf->base + (offset & ~PAGE_MASK); +} + +int erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb, + bool in_metabox) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + + buf->mc = false; + if (in_metabox) { + if (unlikely(!sbi->metabox_inode)) + return -EFSCORRUPTED; + buf->mapping = sbi->metabox_inode->i_mapping; + return 0; + } + if (erofs_is_fileio_mode(sbi)) { + buf->mapping = sbi->managed_cache->i_mapping; + buf->mc = true; + } else { + buf->off = sbi->dif0.fsoff; + buf->mapping = sb->s_bdev->bd_mapping; + } + return 0; +} + +void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, + erofs_off_t offset, bool in_metabox) +{ + int err; + + err = erofs_init_metabuf(buf, sb, in_metabox); + if (err) + return ERR_PTR(err); + return erofs_bread(buf, offset, true); +} + +static int erofs_map_chunks(struct inode *inode, struct erofs_map_blocks *map) +{ + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + struct super_block *sb = inode->i_sb; + struct erofs_inode *vi = EROFS_I(inode); + struct erofs_inode_chunk_index *idx; + unsigned int unit = vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES ? + sizeof(*idx) : EROFS_BLOCK_MAP_ENTRY_SIZE; + erofs_blk_t addrmask = (vi->chunkformat & EROFS_CHUNK_FORMAT_48BIT) ? + BIT_ULL(48) - 1 : BIT_ULL(32) - 1; + u64 nr = map->m_la >> vi->chunkbits, chunksize = 1ULL << vi->chunkbits; + erofs_off_t pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + + vi->xattr_isize, unit) + unit * nr; + /* m_llen will be clamped to EOF in the end */ + erofs_off_t endpos = round_up(pos + 1, sb->s_blocksize); + u64 last, addr; + + idx = erofs_read_metabuf(&buf, sb, pos, erofs_inode_in_metabox(inode)); + if (IS_ERR(idx)) + return PTR_ERR(idx); + + map->m_la = nr << vi->chunkbits; + map->m_llen = 0; + nr = 0; + do { + if (unit == EROFS_BLOCK_MAP_ENTRY_SIZE) { + addr = le32_to_cpu(((__le32 *)idx)[nr]); + if (addr == (u32)EROFS_NULL_ADDR) + addr = EROFS_NULL_ADDR; + } else { + addr = (((u64)le16_to_cpu(idx[nr].startblk_hi) << 32) | + le32_to_cpu(idx[nr].startblk_lo)) & addrmask; + if (addr ^ (EROFS_NULL_ADDR & addrmask)) + addr |= (u64)(le16_to_cpu(idx[nr].device_id) & + EROFS_SB(sb)->device_id_mask) << 48; + else + addr = EROFS_NULL_ADDR; + } + if (!nr) { + last = addr; + continue; + } + /* expand and account the prior chunk here */ + map->m_llen += chunksize; + if (last != EROFS_NULL_ADDR) + last += erofs_blknr(sb, chunksize); + } while (addr == last && pos + (++nr) * unit < endpos); + + if (last != EROFS_NULL_ADDR) { + map->m_pa = erofs_pos(sb, last & addrmask) - map->m_llen; + map->m_deviceid = last >> 48; + map->m_flags = EROFS_MAP_MAPPED; + } + if (addr == last) + map->m_llen += chunksize; + map->m_llen = min_t(erofs_off_t, map->m_llen, + round_up(inode->i_size - map->m_la, sb->s_blocksize)); + erofs_put_metabuf(&buf); + 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); + bool tailinline = (vi->datalayout == EROFS_INODE_FLAT_INLINE); + erofs_off_t pos; + int err = 0; + + trace_erofs_map_blocks_enter(inode, map, 0); + map->m_deviceid = 0; + map->m_flags = 0; + if (map->m_la >= inode->i_size) + goto out; + if (vi->datalayout == EROFS_INODE_CHUNK_BASED) { + err = erofs_map_chunks(inode, map); + } else if (tailinline || vi->startblk != EROFS_NULL_ADDR) { + pos = erofs_pos(sb, erofs_iblks(inode) - tailinline); + map->m_flags = EROFS_MAP_MAPPED; + if (map->m_la < pos) { + map->m_pa = erofs_pos(sb, vi->startblk) + map->m_la; + map->m_llen = pos - map->m_la; + } else { + map->m_pa = erofs_iloc(inode) + vi->inode_isize + + vi->xattr_isize + erofs_blkoff(sb, map->m_la); + map->m_llen = inode->i_size - map->m_la; + map->m_flags |= EROFS_MAP_META; + if (erofs_blkoff(sb, map->m_pa) + map->m_llen > + sb->s_blocksize) { + erofs_err(sb, "inline data across blocks @ nid %llu", vi->nid); + return -EFSCORRUPTED; + } + } + } +out: + map->m_plen = err ? 0 : map->m_llen; + trace_erofs_map_blocks_exit(inode, map, 0, err); + return err; +} + +static void erofs_fill_from_devinfo(struct erofs_map_dev *map, + struct super_block *sb, struct erofs_device_info *dif) +{ + map->m_sb = sb; + map->m_dif = dif; + map->m_bdev = NULL; + if (dif->file && S_ISBLK(file_inode(dif->file)->i_mode)) + map->m_bdev = file_bdev(dif->file); +} + +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; + erofs_off_t startoff; + int id; + + erofs_fill_from_devinfo(map, sb, &EROFS_SB(sb)->dif0); + map->m_bdev = sb->s_bdev; /* use s_bdev for the primary device */ + 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->uniaddr); + up_read(&devs->rwsem); + return 0; + } + erofs_fill_from_devinfo(map, sb, dif); + up_read(&devs->rwsem); + } else if (devs->extra_devices && !devs->flatdev) { + down_read(&devs->rwsem); + idr_for_each_entry(&devs->tree, dif, id) { + if (!dif->uniaddr) + continue; + + startoff = erofs_pos(sb, dif->uniaddr); + if (map->m_pa >= startoff && + map->m_pa < startoff + erofs_pos(sb, dif->blocks)) { + map->m_pa -= startoff; + erofs_fill_from_devinfo(map, sb, dif); + break; + } + } + up_read(&devs->rwsem); + } + return 0; +} + +/* + * bit 30: I/O error occurred on this folio + * bit 29: CPU has dirty data in D-cache (needs aliasing handling); + * bit 0 - 29: remaining parts to complete this folio + */ +#define EROFS_ONLINEFOLIO_EIO 30 +#define EROFS_ONLINEFOLIO_DIRTY 29 + +void erofs_onlinefolio_init(struct folio *folio) +{ + union { + atomic_t o; + void *v; + } u = { .o = ATOMIC_INIT(1) }; + + folio->private = u.v; /* valid only if file-backed folio is locked */ +} + +void erofs_onlinefolio_split(struct folio *folio) +{ + atomic_inc((atomic_t *)&folio->private); +} + +void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty) +{ + int orig, v; + + do { + orig = atomic_read((atomic_t *)&folio->private); + DBG_BUGON(orig <= 0); + v = dirty << EROFS_ONLINEFOLIO_DIRTY; + v |= (orig - 1) | (!!err << EROFS_ONLINEFOLIO_EIO); + } while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig); + + if (v & (BIT(EROFS_ONLINEFOLIO_DIRTY) - 1)) + return; + folio->private = 0; + if (v & BIT(EROFS_ONLINEFOLIO_DIRTY)) + flush_dcache_folio(folio); + folio_end_read(folio, !(v & BIT(EROFS_ONLINEFOLIO_EIO))); +} + +struct erofs_iomap_iter_ctx { + struct page *page; + void *base; + struct inode *realinode; +}; + +static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) +{ + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); + struct erofs_iomap_iter_ctx *ctx = iter->private; + struct inode *realinode = ctx ? ctx->realinode : inode; + struct super_block *sb = realinode->i_sb; + struct erofs_map_blocks map; + struct erofs_map_dev mdev; + int ret; + + map.m_la = offset; + map.m_llen = length; + ret = erofs_map_blocks(realinode, &map); + if (ret < 0) + return ret; + + iomap->offset = map.m_la; + iomap->length = map.m_llen; + iomap->flags = 0; + iomap->addr = IOMAP_NULL_ADDR; + if (!(map.m_flags & EROFS_MAP_MAPPED)) { + iomap->type = IOMAP_HOLE; + return 0; + } + + if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(realinode)) { + 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; + + if (flags & IOMAP_DAX) + iomap->dax_dev = mdev.m_dif->dax_dev; + else + iomap->bdev = mdev.m_bdev; + iomap->addr = mdev.m_dif->fsoff + mdev.m_pa; + if (flags & IOMAP_DAX) + iomap->addr += mdev.m_dif->dax_part_off; + } + + if (map.m_flags & EROFS_MAP_META) { + iomap->type = IOMAP_INLINE; + /* read context should read the inlined data */ + if (ctx) { + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + void *ptr; + + ptr = erofs_read_metabuf(&buf, sb, map.m_pa, + erofs_inode_in_metabox(realinode)); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + iomap->inline_data = ptr; + ctx->page = buf.page; + ctx->base = buf.base; + } + } else { + iomap->type = IOMAP_MAPPED; + } + 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) +{ + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); + struct erofs_iomap_iter_ctx *ctx = iter->private; + + if (ctx && ctx->base) { + struct erofs_buf buf = { + .page = ctx->page, + .base = ctx->base, + }; + + DBG_BUGON(iomap->type != IOMAP_INLINE); + erofs_put_metabuf(&buf); + ctx->base = NULL; + } + return written; +} + +static DEFINE_IOMAP_ITER_NEXT_END(erofs_iomap_next, erofs_iomap_begin, + erofs_iomap_end); + +static const struct iomap_ops erofs_iomap_ops = { + .iomap_next = erofs_iomap_next, +}; + +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)) { + if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP)) + return -EOPNOTSUPP; + return iomap_fiemap(inode, fieinfo, start, len, + &z_erofs_iomap_report_ops); + } + 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) +{ + struct iomap_read_folio_ctx read_ctx = { + .ops = &iomap_bio_read_ops, + .cur_folio = folio, + }; + bool need_iput; + struct erofs_iomap_iter_ctx iter_ctx = { + .realinode = erofs_real_inode(folio_inode(folio), &need_iput), + }; + + trace_erofs_read_folio(iter_ctx.realinode, folio, true); + iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx); + if (need_iput) + iput(iter_ctx.realinode); + return 0; +} + +static void erofs_readahead(struct readahead_control *rac) +{ + struct iomap_read_folio_ctx read_ctx = { + .ops = &iomap_bio_read_ops, + .rac = rac, + }; + bool need_iput; + struct erofs_iomap_iter_ctx iter_ctx = { + .realinode = erofs_real_inode(rac->mapping->host, &need_iput), + }; + + trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac), + readahead_count(rac), true); + iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx); + if (need_iput) + iput(iter_ctx.realinode); +} + +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; + + if (IS_ENABLED(CONFIG_FS_DAX) && IS_DAX(inode)) + return dax_iomap_rw(iocb, to, &erofs_iomap_ops); + + if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_sb->s_bdev) { + struct erofs_iomap_iter_ctx iter_ctx = { + .realinode = inode, + }; + + return iomap_dio_rw(iocb, to, &erofs_iomap_ops, + NULL, 0, &iter_ctx, 0); + } + return filemap_read(iocb, to, 0); +} + +/* for uncompressed (aligned) files and raw access for other files */ +const struct address_space_operations erofs_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_prepare(struct vm_area_desc *desc) +{ + if (!IS_DAX(file_inode(desc->file))) + return generic_file_readonly_mmap_prepare(desc); + + if (vma_desc_test_all(desc, VMA_SHARED_BIT, VMA_MAYWRITE_BIT)) + return -EINVAL; + + desc->vm_ops = &erofs_dax_vm_ops; + vma_desc_set_flags(desc, VMA_HUGEPAGE_BIT); + return 0; +} +#else +#define erofs_file_mmap_prepare generic_file_readonly_mmap_prepare +#endif + +loff_t erofs_file_llseek(struct file *file, loff_t offset, int whence) +{ + struct inode *inode = file->f_mapping->host; + const struct iomap_ops *ops = &erofs_iomap_ops; + + if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) { + if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP)) + return generic_file_llseek(file, offset, whence); + ops = &z_erofs_iomap_report_ops; + } + + if (whence == SEEK_HOLE) + offset = iomap_seek_hole(inode, offset, ops); + else if (whence == SEEK_DATA) + offset = iomap_seek_data(inode, offset, ops); + else + return generic_file_llseek(file, offset, whence); + + if (offset < 0) + return offset; + return vfs_setpos(file, offset, inode->i_sb->s_maxbytes); +} + +const struct file_operations erofs_file_fops = { + .llseek = erofs_file_llseek, + .read_iter = erofs_file_read_iter, + .unlocked_ioctl = erofs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = erofs_compat_ioctl, +#endif + .mmap_prepare = erofs_file_mmap_prepare, + .get_unmapped_area = thp_get_unmapped_area, + .splice_read = filemap_splice_read, + .setlease = generic_setlease, +}; |