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| author |   Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-10-09 04:08:37 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-10-18 00:15:55 +0800 |
| commit | 8f89926290c4b3d31748d5089b27952243be0693 (patch) | |
| tree | 10ae1736dcfdbff04abdd9e9354fd27369e7c449 /fs/erofs/zmap.c | |
| parent | erofs: add multiple device support (diff) | |
| download | linux-dev-8f89926290c4b3d31748d5089b27952243be0693.tar.xz linux-dev-8f89926290c4b3d31748d5089b27952243be0693.zip | |
erofs: get compression algorithms directly on mapping
Currently, z_erofs_map_blocks_iter() returns whether extents are
compressed or not, and the decompression frontend gets the specific
algorithms then.
It works but not quite well in many aspests, for example:
- The decompression frontend has to deal with whether extents are
compressed or not again and lookup the algorithms if compressed.
It's duplicated and too detailed about the on-disk mapping.
- A new secondary compression head will be introduced later so that
each file can have 2 compression algorithms at most for different
type of data. It could increase the complexity of the decompression
frontend if still handled in this way;
- A new readmore decompression strategy will be introduced to get
better performance for much bigger pcluster and lzma, which needs
the specific algorithm in advance as well.
Let's look up compression algorithms in z_erofs_map_blocks_iter()
directly instead.
Link: https://lore.kernel.org/r/20211008200839.24541-2-xiang@kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/zmap.c')
| -rw-r--r-- | fs/erofs/zmap.c | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 7a6df35fdc91..1c3b068e5a42 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -111,7 +111,7 @@ struct z_erofs_maprecorder { unsigned long lcn; /* compression extent information gathered */ - u8 type; + u8 type, headtype; u16 clusterofs; u16 delta[2]; erofs_blk_t pblk, compressedlcs; @@ -446,9 +446,8 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, } return z_erofs_extent_lookback(m, m->delta[0]); case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: - map->m_flags &= ~EROFS_MAP_ZIPPED; - fallthrough; case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: + m->headtype = m->type; map->m_la = (lcn << lclusterbits) | m->clusterofs; break; default: @@ -472,7 +471,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN && m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD); - if (!(map->m_flags & EROFS_MAP_ZIPPED) || + if (m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN || !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) { map->m_plen = 1 << lclusterbits; return 0; @@ -609,16 +608,14 @@ int z_erofs_map_blocks_iter(struct inode *inode, if (err) goto unmap_out; - map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */ + map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED; end = (m.lcn + 1ULL) << lclusterbits; switch (m.type) { case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: - if (endoff >= m.clusterofs) - map->m_flags &= ~EROFS_MAP_ZIPPED; - fallthrough; case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: if (endoff >= m.clusterofs) { + m.headtype = m.type; map->m_la = (m.lcn << lclusterbits) | m.clusterofs; break; } @@ -650,12 +647,16 @@ int z_erofs_map_blocks_iter(struct inode *inode, map->m_llen = end - map->m_la; map->m_pa = blknr_to_addr(m.pblk); - map->m_flags |= EROFS_MAP_MAPPED; err = z_erofs_get_extent_compressedlen(&m, initial_lcn); if (err) goto out; + if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) + map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; + else + map->m_algorithmformat = vi->z_algorithmtype[0]; + if (flags & EROFS_GET_BLOCKS_FIEMAP) { err = z_erofs_get_extent_decompressedlen(&m); if (!err) |