From: Gao Xiang Date: Mon, 15 Jun 2026 07:37:35 +0000 (+0800) Subject: erofs: introduce erofs_map_chunks() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=99980e9a7eca5ba3f4a2892acb0ccdcc7fe1dd8f;p=thirdparty%2Flinux.git erofs: introduce erofs_map_chunks() Try to map more chunks in the same metadata on-disk block for more efficient IO performance. Signed-off-by: Gao Xiang --- diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 44da21c9d7776..cdf2e2ef8ea84 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -98,17 +98,73 @@ void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb, return erofs_bread(buf, offset, true); } -int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) +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; - unsigned int unit, blksz = sb->s_blocksize; struct erofs_inode *vi = EROFS_I(inode); struct erofs_inode_chunk_index *idx; - erofs_blk_t startblk, addrmask; - bool tailpacking; + 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; - u64 chunknr; int err = 0; trace_erofs_map_blocks_enter(inode, map, 0); @@ -116,13 +172,10 @@ int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) map->m_flags = 0; if (map->m_la >= inode->i_size) goto out; - - if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { - tailpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE); - if (!tailpacking && vi->startblk == EROFS_NULL_ADDR) - goto out; - pos = erofs_pos(sb, erofs_iblks(inode) - tailpacking); - + 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; @@ -132,57 +185,15 @@ int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map) vi->xattr_isize + erofs_blkoff(sb, map->m_la); map->m_llen = inode->i_size - map->m_la; map->m_flags |= EROFS_MAP_META; - } - 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; - - idx = erofs_read_metabuf(&buf, sb, pos, erofs_inode_in_metabox(inode)); - if (IS_ERR(idx)) { - err = PTR_ERR(idx); - goto out; - } - map->m_la = chunknr << vi->chunkbits; - map->m_llen = min_t(erofs_off_t, 1UL << vi->chunkbits, - round_up(inode->i_size - map->m_la, blksz)); - if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES) { - addrmask = (vi->chunkformat & EROFS_CHUNK_FORMAT_48BIT) ? - BIT_ULL(48) - 1 : BIT_ULL(32) - 1; - startblk = (((u64)le16_to_cpu(idx->startblk_hi) << 32) | - le32_to_cpu(idx->startblk_lo)) & addrmask; - if ((startblk ^ EROFS_NULL_ADDR) & addrmask) { - map->m_deviceid = le16_to_cpu(idx->device_id) & - EROFS_SB(sb)->device_id_mask; - map->m_pa = erofs_pos(sb, startblk); - map->m_flags = EROFS_MAP_MAPPED; - } - } else { - startblk = le32_to_cpu(*(__le32 *)idx); - if (startblk != (u32)EROFS_NULL_ADDR) { - map->m_pa = erofs_pos(sb, startblk); - map->m_flags = EROFS_MAP_MAPPED; + 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; + } } } - erofs_put_metabuf(&buf); out: - if (!err) { - map->m_plen = map->m_llen; - /* inline data should be located in the same meta block */ - if ((map->m_flags & EROFS_MAP_META) && - erofs_blkoff(sb, map->m_pa) + map->m_plen > blksz) { - erofs_err(sb, "inline data across blocks @ nid %llu", vi->nid); - DBG_BUGON(1); - return -EFSCORRUPTED; - } - } + map->m_plen = err ? 0 : map->m_llen; trace_erofs_map_blocks_exit(inode, map, 0, err); return err; }