Re: [PATCH v2] vfs: prevent copy_file_range to copy across devices

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 2021-02-15 at 15:43 +0000, Luis Henriques wrote:
> Nicolas Boichat reported an issue when trying to use the
> copy_file_range
> syscall on a tracefs file.  It failed silently because the file
> content is
> generated on-the-fly (reporting a size of zero) and copy_file_range
> needs
> to know in advance how much data is present.

That explanation makes no sense whatsoever. copy_file_range is a non-
atomic operation and so the file can change while being copied. Any
determination of 'how much data is present' that is made in advance
would therefore be a flaw in the copy process being used (i.e.
do_splice_direct()). Does sendfile() also 'issue' in the same way?


-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@xxxxxxxxxxxxxxx






[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux