Re: [PATCH v2 5/5] nfs: don't clear STATX_ATIME from result_mask

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

 



On Fri, Oct 19, 2018 at 8:14 PM, Trond Myklebust
<trondmy@xxxxxxxxxxxxxxx> wrote:
> On Fri, 2018-10-19 at 19:46 +0200, Miklos Szeredi wrote:

>> How is it then that only STATX_ATIME is cleared and not the other
>> fields?
>
> It isn't just the atime. We can also fail to revalidate the ctime and
> mtime if they are not being requested by the user.
>
>>
>> Note: junk != stale.  The statx definition doesn't talk about the
>> fields being up-to-date, except for AT_STATX_FORCE_SYNC, so stale
>> attributes are okay, and do not warrant clearing the result_mask.
>>
>
> I disagree. stale == junk here, because the default of
> AT_STATX_SYNC_AS_STAT is described by the manpage as "Do  whatever
> stat(2) does." which this is not.

Ah, you are talking about this:

    /* Is the user requesting attributes that might need revalidation? */
    if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
                    STATX_MTIME|STATX_UID|STATX_GID|
                    STATX_SIZE|STATX_BLOCKS)))
        goto out_no_update;

Well, if this is triggered for statx(...,  STATX_ATIME,
AT_STATX_SYNC_AS_STAT) and MNT_NOATIME, then yes, result will be junk.
Which means that the code is wrong, it shouldn't do that.

Otherwise (if something other than STATX_ATIME or STATX_INO or
STATX_TYPE is given as well) it *will* do the same thing as what
stat(2) does, so in that case STATX_ATIME should not  be cleared (yet
it is cleared).

I can do a patch, but not tonight...

Thanks,
Miklos


Thanks,
Miklos



[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