Hi, Gao Xiang, Thanks for you answer, I understand now. In addition, I sent a patch to fix the clerical error here. It seems that the compilation won't be affected under the default configuration.
Thanks, Jianan -------------- Huang Jianan >Hi Jianan, > >On Mon, Oct 19, 2020 at 11:13:42AM +0800, [email protected] wrote: >> Hi, Gao Xiang锟斤拷 >> ________________________________ >> >> 锟斤拷锟斤拷锟剿ｏ拷 Gao Xiang<mailto:[email protected]> >> 锟斤拷锟斤拷时锟戒： 2020-10-17 13:16 >> 锟秸硷拷锟剿ｏ拷 linux-erofs<mailto:[email protected]> >> 锟斤拷锟酵ｏ拷 Huang Jianan<mailto:[email protected]>; Li >> Guifu<mailto:[email protected]>; Li >> Guifu<mailto:[email protected]>; Chao Yu<mailto:[email protected]>; Guo >> Weichao<mailto:[email protected]>; Zhang >> Shiming<mailto:[email protected]>; Gao Xiang<mailto:[email protected]> >> 锟斤拷锟解： [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 <[email protected]> >> Signed-off-by: Gao Xiang <[email protected]> >> --- >> 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? > >Thanks for your question. >The idea is that we requested the extent with > > map.m_la = end - 1; > > ret = z_erofs_map_blocks_iter(vnode, &map); > if (ret) > return ret; > >so the extent must include "end - 1", so >it's impossible that "end > map.m_la + map.m_llen" >(invalid return). > >or the entire extent would be holed extent, anyway, >that is another extent rather than a data extent. > >(BTW, the up-to-date commits is at >https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git/log/?h=wip/experimental_fuse >kindly check out them as well :) ) > >Thanks, >Gao Xiang > > >> >> + count = map.m_llen; >> + partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED); >> } >> if ((off_t)map.m_la < offset) { >> -- >> 2.24.0 >> >> Thanks, >> Jianan > ________________________________ OPPO 本电子邮件及其附件含有OPPO公司的保密信息，仅限于邮件指明的收件人使用（包含个人及群组）。禁止任何人在未经授权的情况下以任何形式使用。如果您错收了本邮件，请立即以电子邮件通知发件人并删除本邮件及其附件。 This e-mail and its attachments contain confidential information from OPPO, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!
