Am Donnerstag, 18. Dezember 2014, 13:22:20 schrieb leroy christophe:

Hi Leroy, Herbert,

Le 18/12/2014 13:15, Stephan Mueller a écrit :

quoted

Hi Herbert,

While testing the vmsplice/splice interface of algif_hash I was made
aware of the problem that data blobs larger than 16 pages do not seem
to be hashed properly.

For testing, a file is mmap()ed and handed to vmsplice / splice. If
the file is smaller than 2**16, the interface returns the proper
hash. However, when the file is larger, only the first 2**16 bytes
seem to be used.

When adding printk's to hash_sendpage, I see that this function is
invoked exactly 16 times where the first 15 invocations have the
MSG_MORE flag set and the last invocation does not have MSG_MORE.

Hi Stephan,

I have already noticed the same issue and proposed a patch, but I never
got any feedback and it has never been merged, allthought I pinged it
a few times.

See https://lkml.org/lkml/2014/4/18/276

Thanks a lot for pointing to this patch.

Herbert, do you see a problem in this patch? If no, would it be possible 
that you ping the VFS maintainer as I guess your word carries more 
weight?

In any case, I will test that patch tonight.

Thanks
Stephan