Re: [PATCH] splice: fix wrong __splice_from_pipe() usage

OGAWA Hirofumi
2007-07-16T12:36:12Z

Jens Axboe <jens.axboe@oracle.com> writes:

>> nfsd_vfs_read() path.
>>
>> nfsd_vfs_read()
>> splice_direct_to_actor()
>> while(len) {
>> do_splice_to() [update sd->pos]
>> -> generic_file_splice_read() [read from sd->pos]
>> nfsd_direct_splice_actor()
>> -> __splice_from_pipe() [update sd->pos]
>> }
>>
>> do_splice_to() updates sd->pos for read, and pass updated sd to
>> __splice_from_pipe(), and __splice_from_pipe() updates sd->pos for
>> write. So, next do_splice_to() read from wrong position.
>
> Ah, I see. Copying the structure over would work, but it seems like a
> big work-around for something that is essentially bad behaviour in the
> splice core for direct splicing.
>
> Can you check if this works for you?

Simple test was done. The patch works for me.

Thanks.