发件人： Gao Xiang

发送时间： 2020-10-17 13:16

收件人： linux-erofs

抄送： Huang Jianan; Li Guifu; Li Guifu; Chao Yu; Guo Weichao; Zhang Shiming; Gao Xiang

主题： [WIP] [PATCH 04/12] erofs-utils: fuse: adjust larger extent handling

so more easy to understand.

 

[ let's fold in to the original patch. ]

Cc: Huang Jianan <huangjianan@oppo.com>

Signed-off-by: Gao Xiang <hsiangkao@aol.com>

---

fuse/read.c | 13 +++++++++----

1 file changed, 9 insertions(+), 4 deletions(-)

 

diff --git a/fuse/read.c b/fuse/read.c

index 0d0e3b0fa468..dd44adaa1c40 100644

--- a/fuse/read.c

+++ b/fuse/read.c

@@ -112,12 +112,17 @@ size_t erofs_read_data_compression(struct erofs_vnode *vnode, char *buffer,

Z_EROFS_COMPRESSION_LZ4 :

Z_EROFS_COMPRESSION_SHIFTED;

- if (end >= map.m_la + map.m_llen) {

- count = map.m_llen;

- partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED);

- } else {

+ /*

+ * trim to the needed size if the returned extent is quite

+ * larger than requested, and set up partial flag as well.

+ */

+ if (end < map.m_la + map.m_llen) {

count = end - map.m_la;

partial = true;

+ } else {

+ ASSERT(end == map.m_la + map_m_llen);

I think you mean map.m_llen intesad of map_m_llen.

Besides, I don't understand why add ASSERT here. 

I think this condition will be true if offset+size is exactly the end of a compressed block?

+ count = map.m_llen;

+ partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED);

}

if ((off_t)map.m_la < offset) {

--

2.24.0

Thanks,

Jianan