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| author | Yue Hu <huyue2@coolpad.com> | 2022-09-23 10:11:21 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2022-09-23 10:55:56 +0800 |
| commit | fdffc091e6f94602558bba712b51bc16f79fd6d5 (patch) | |
| tree | d6daa04f5f2e867786577dca54fd0ef194145fa5 /fs/erofs/zmap.c | |
| parent | 1ae9470c3e14624b0f4d8741c22b5a94062c0e33 (diff) | |
| download | linux-fdffc091e6f94602558bba712b51bc16f79fd6d5.tar.gz linux-fdffc091e6f94602558bba712b51bc16f79fd6d5.tar.bz2 linux-fdffc091e6f94602558bba712b51bc16f79fd6d5.zip | |
erofs: support interlaced uncompressed data for compressed files
Currently, uncompressed data is all handled in the shifted way, which
means we have to shift the whole on-disk plain pcluster to get the
logical data. However, since we are also using in-place I/O for
uncompressed data, data copy will be reduced a lot if pcluster is
recorded in the interlaced way as illustrated below:
_______________________________________________________________
| | | |_ tail part |_ head part _|
|<- blk0 ->| .. |<- blkn-2 ->|<- blkn-1 ->|
The logical data then becomes:
________________________________________________________
|_ head part _|_ blk0 _| .. |_ blkn-2 _|_ tail part _|
In addition, non-4k plain pclusters are also survived by the
interlaced way, which can be used for non-4k lclusters as well.
However, it's almost impossible to de-duplicate uncompressed data
in the interlaced way, therefore shifted uncompressed data is still
useful.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/8369112678604fdf4ef796626d59b1fdd0745a53.1663898962.git.huyue2@coolpad.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/zmap.c')
| -rw-r--r-- | fs/erofs/zmap.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index d58549ca1df9..7196235a441c 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -679,12 +679,18 @@ static int z_erofs_do_map_blocks(struct inode *inode, goto out; } - if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) - map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; - else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) + if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) { + if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER) + map->m_algorithmformat = + Z_EROFS_COMPRESSION_INTERLACED; + else + map->m_algorithmformat = + Z_EROFS_COMPRESSION_SHIFTED; + } else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) { map->m_algorithmformat = vi->z_algorithmtype[1]; - else + } else { map->m_algorithmformat = vi->z_algorithmtype[0]; + } if ((flags & EROFS_GET_BLOCKS_FIEMAP) || ((flags & EROFS_GET_BLOCKS_READMORE) && |