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* Re: [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits
       [not found] <20190829041132.26677-1-deepa.kernel@gmail.com>
@ 2019-08-29  4:38 ` Deepa Dinamani
  2019-08-30  1:20   ` Mike Marshall
  0 siblings, 1 reply; 5+ messages in thread
From: Deepa Dinamani @ 2019-08-29  4:38 UTC (permalink / raw)
  To: Alexander Viro, Arnd Bergmann
  Cc: Latchesar Ionkov, martin, jfs-discussion, Dave Kleikamp, al,
	Bob Copeland, Adrian Hunter, Andreas Dilger, mikulas,
	stoph Hellwig, nico, Mike Marshall, linux-cifs, Yan, Zheng,
	Sage Weil, Darrick J. Wong, y2038 Mailman List,
	Richard Weinberger, Steve French, Anton Vorontsov, linux,
	codalist, Christoph Hellwig, coda, V9FS Developers, Ilya Dryomov,
	Ext4 Developers List, salah.triki, asmadeus, devel,
	Evgeniy Dushistov, Kees Cook, Eric Van Hensbergen, Jan Kara,
	reiserfs-devel, Tejun Heo, Joel Becker, aivazian.tigran, phillip,
	David Sterba, Jaegeuk Kim, ceph-devel, trond.myklebust,
	OGAWA Hirofumi, Andreas Dilger, Jan Harkes,
	Linux NFS Mailing List, Tony Luck, Theodore Ts'o, luisbg,
	Artem Bityutskiy, linux-ntfs-dev, Greg KH, linux-karma-devel,
	jlayton, Linux Kernel Mailing List, Linux F2FS DEV, Mailing List,
	linux-xfs, Colin Cross, Linux FS-devel Mailing List, linux-mtd,
	David Woodhouse, Anna Schumaker

Adding the others who were on original cc, just in case.
- Deepa

On Wed, Aug 28, 2019 at 9:12 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
>
> Hi Al, Arnd,
>
> This is a pull request for filling in min and max timestamps for filesystems.
> I've added all the acks, and dropped the adfs patch. That will be merged through
> Russell's tree.
>
> Thanks,
> Deepa
>
> The following changes since commit 5d18cb62218608a1388858880ad3ec76d6cb0d3b:
>
>   Add linux-next specific files for 20190828 (2019-08-28 19:59:14 +1000)
>
> are available in the Git repository at:
>
>   https://github.com/deepa-hub/vfs limits
>
> for you to fetch changes up to f0f216afa4c7e4dee9121fde52ccf57f76119188:
>
>   isofs: Initialize filesystem timestamp ranges (2019-08-28 19:19:36 -0700)
>
> ----------------------------------------------------------------
> Deepa Dinamani (19):
>       vfs: Add file timestamp range support
>       vfs: Add timestamp_truncate() api
>       timestamp_truncate: Replace users of timespec64_trunc
>       mount: Add mount warning for impending timestamp expiry
>       utimes: Clamp the timestamps before update
>       fs: Fill in max and min timestamps in superblock
>       9p: Fill min and max timestamps in sb
>       ext4: Initialize timestamps limits
>       fs: nfs: Initialize filesystem timestamp ranges
>       fs: cifs: Initialize filesystem timestamp ranges
>       fs: fat: Initialize filesystem timestamp ranges
>       fs: affs: Initialize filesystem timestamp ranges
>       fs: sysv: Initialize filesystem timestamp ranges
>       fs: ceph: Initialize filesystem timestamp ranges
>       fs: orangefs: Initialize filesystem timestamp ranges
>       fs: hpfs: Initialize filesystem timestamp ranges
>       fs: omfs: Initialize filesystem timestamp ranges
>       pstore: fs superblock limits
>       isofs: Initialize filesystem timestamp ranges
>
>  fs/9p/vfs_super.c        |  6 +++++-
>  fs/affs/amigaffs.c       |  2 +-
>  fs/affs/amigaffs.h       |  3 +++
>  fs/affs/inode.c          |  4 ++--
>  fs/affs/super.c          |  4 ++++
>  fs/attr.c                | 21 ++++++++++++---------
>  fs/befs/linuxvfs.c       |  2 ++
>  fs/bfs/inode.c           |  2 ++
>  fs/ceph/super.c          |  2 ++
>  fs/cifs/cifsfs.c         | 22 ++++++++++++++++++++++
>  fs/cifs/netmisc.c        | 14 +++++++-------
>  fs/coda/inode.c          |  3 +++
>  fs/configfs/inode.c      | 12 ++++++------
>  fs/cramfs/inode.c        |  2 ++
>  fs/efs/super.c           |  2 ++
>  fs/ext2/super.c          |  2 ++
>  fs/ext4/ext4.h           | 10 +++++++++-
>  fs/ext4/super.c          | 17 +++++++++++++++--
>  fs/f2fs/file.c           | 21 ++++++++++++---------
>  fs/fat/inode.c           | 12 ++++++++++++
>  fs/freevxfs/vxfs_super.c |  2 ++
>  fs/hpfs/hpfs_fn.h        |  6 ++----
>  fs/hpfs/super.c          |  2 ++
>  fs/inode.c               | 33 ++++++++++++++++++++++++++++++++-
>  fs/isofs/inode.c         |  7 +++++++
>  fs/jffs2/fs.c            |  3 +++
>  fs/jfs/super.c           |  2 ++
>  fs/kernfs/inode.c        |  7 +++----
>  fs/minix/inode.c         |  2 ++
>  fs/namespace.c           | 33 ++++++++++++++++++++++++++++++++-
>  fs/nfs/super.c           | 20 +++++++++++++++++++-
>  fs/ntfs/inode.c          | 21 ++++++++++++---------
>  fs/omfs/inode.c          |  4 ++++
>  fs/orangefs/super.c      |  2 ++
>  fs/pstore/ram.c          |  2 ++
>  fs/qnx4/inode.c          |  2 ++
>  fs/qnx6/inode.c          |  2 ++
>  fs/reiserfs/super.c      |  3 +++
>  fs/romfs/super.c         |  2 ++
>  fs/squashfs/super.c      |  2 ++
>  fs/super.c               |  2 ++
>  fs/sysv/super.c          |  5 ++++-
>  fs/ubifs/file.c          | 21 ++++++++++++---------
>  fs/ufs/super.c           |  7 +++++++
>  fs/utimes.c              |  6 ++----
>  fs/xfs/xfs_super.c       |  2 ++
>  include/linux/fs.h       |  5 +++++
>  include/linux/time64.h   |  2 ++
>  48 files changed, 298 insertions(+), 72 deletions(-)


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits
  2019-08-29  4:38 ` [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits Deepa Dinamani
@ 2019-08-30  1:20   ` Mike Marshall
  2019-08-30  2:02     ` Deepa Dinamani
  0 siblings, 1 reply; 5+ messages in thread
From: Mike Marshall @ 2019-08-30  1:20 UTC (permalink / raw)
  To: Deepa Dinamani
  Cc: Latchesar Ionkov, Martin Brandenburg, jfs-discussion,
	Dave Kleikamp, al, Bob Copeland, Adrian Hunter, Andreas Dilger,
	mikulas, stoph Hellwig, nico, linux-cifs, Yan, Zheng, Sage Weil,
	Darrick J. Wong, y2038 Mailman List, Richard Weinberger,
	Steve French, Anton Vorontsov, linux, codalist,
	Christoph Hellwig, coda, V9FS Developers, Ilya Dryomov,
	Ext4 Developers List, salah.triki, asmadeus, devel,
	Evgeniy Dushistov, Kees Cook, Arnd Bergmann, Eric Van Hensbergen,
	Jan Kara, reiserfs-devel, Tejun Heo, Alexander Viro,
	aivazian.tigran, phillip, David Sterba, Jaegeuk Kim, ceph-devel,
	trond.myklebust, OGAWA Hirofumi, Andreas Dilger, Jan Harkes,
	Linux NFS Mailing List, Tony Luck, Theodore Ts'o, luisbg,
	Artem Bityutskiy, linux-ntfs-dev, Greg KH, linux-karma-devel,
	jlayton, Linux Kernel Mailing List, Linux F2FS DEV, Mailing List,
	linux-xfs, Colin Cross, Linux FS-devel Mailing List, linux-mtd,
	David Woodhouse, Anna Schumaker, Joel Becker

Hi Deepa...

I installed this patch series on top of Linux 5.3-rc6 and ran xfstests
on orangefs and got a regression... generic/258 failed
with: "Timestamp wrapped"...

# cat results/generic/258.out.bad
QA output created by 258
Creating file with timestamp of Jan 1, 1960
Testing for negative seconds since epoch
Timestamp wrapped: 0
Timestamp wrapped
(see /home/hubcap/xfstests-dev/results//generic/258.full for details)

Just to double check, I compiled Linux 5.3-rc6 without the timestamp series,
and 258 passed... then added the patch series back and the failure returned...

Also.... when I was using "git am" to apply the patch series, the ceph patch
failed, so I "git skipped" it...

I obtained the patch series from: https://github.com/deepa-hub/vfs limits
today.

-Mike

On Thu, Aug 29, 2019 at 12:38 AM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
>
> Adding the others who were on original cc, just in case.
> - Deepa
>
> On Wed, Aug 28, 2019 at 9:12 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> >
> > Hi Al, Arnd,
> >
> > This is a pull request for filling in min and max timestamps for filesystems.
> > I've added all the acks, and dropped the adfs patch. That will be merged through
> > Russell's tree.
> >
> > Thanks,
> > Deepa
> >
> > The following changes since commit 5d18cb62218608a1388858880ad3ec76d6cb0d3b:
> >
> >   Add linux-next specific files for 20190828 (2019-08-28 19:59:14 +1000)
> >
> > are available in the Git repository at:
> >
> >   https://github.com/deepa-hub/vfs limits
> >
> > for you to fetch changes up to f0f216afa4c7e4dee9121fde52ccf57f76119188:
> >
> >   isofs: Initialize filesystem timestamp ranges (2019-08-28 19:19:36 -0700)
> >
> > ----------------------------------------------------------------
> > Deepa Dinamani (19):
> >       vfs: Add file timestamp range support
> >       vfs: Add timestamp_truncate() api
> >       timestamp_truncate: Replace users of timespec64_trunc
> >       mount: Add mount warning for impending timestamp expiry
> >       utimes: Clamp the timestamps before update
> >       fs: Fill in max and min timestamps in superblock
> >       9p: Fill min and max timestamps in sb
> >       ext4: Initialize timestamps limits
> >       fs: nfs: Initialize filesystem timestamp ranges
> >       fs: cifs: Initialize filesystem timestamp ranges
> >       fs: fat: Initialize filesystem timestamp ranges
> >       fs: affs: Initialize filesystem timestamp ranges
> >       fs: sysv: Initialize filesystem timestamp ranges
> >       fs: ceph: Initialize filesystem timestamp ranges
> >       fs: orangefs: Initialize filesystem timestamp ranges
> >       fs: hpfs: Initialize filesystem timestamp ranges
> >       fs: omfs: Initialize filesystem timestamp ranges
> >       pstore: fs superblock limits
> >       isofs: Initialize filesystem timestamp ranges
> >
> >  fs/9p/vfs_super.c        |  6 +++++-
> >  fs/affs/amigaffs.c       |  2 +-
> >  fs/affs/amigaffs.h       |  3 +++
> >  fs/affs/inode.c          |  4 ++--
> >  fs/affs/super.c          |  4 ++++
> >  fs/attr.c                | 21 ++++++++++++---------
> >  fs/befs/linuxvfs.c       |  2 ++
> >  fs/bfs/inode.c           |  2 ++
> >  fs/ceph/super.c          |  2 ++
> >  fs/cifs/cifsfs.c         | 22 ++++++++++++++++++++++
> >  fs/cifs/netmisc.c        | 14 +++++++-------
> >  fs/coda/inode.c          |  3 +++
> >  fs/configfs/inode.c      | 12 ++++++------
> >  fs/cramfs/inode.c        |  2 ++
> >  fs/efs/super.c           |  2 ++
> >  fs/ext2/super.c          |  2 ++
> >  fs/ext4/ext4.h           | 10 +++++++++-
> >  fs/ext4/super.c          | 17 +++++++++++++++--
> >  fs/f2fs/file.c           | 21 ++++++++++++---------
> >  fs/fat/inode.c           | 12 ++++++++++++
> >  fs/freevxfs/vxfs_super.c |  2 ++
> >  fs/hpfs/hpfs_fn.h        |  6 ++----
> >  fs/hpfs/super.c          |  2 ++
> >  fs/inode.c               | 33 ++++++++++++++++++++++++++++++++-
> >  fs/isofs/inode.c         |  7 +++++++
> >  fs/jffs2/fs.c            |  3 +++
> >  fs/jfs/super.c           |  2 ++
> >  fs/kernfs/inode.c        |  7 +++----
> >  fs/minix/inode.c         |  2 ++
> >  fs/namespace.c           | 33 ++++++++++++++++++++++++++++++++-
> >  fs/nfs/super.c           | 20 +++++++++++++++++++-
> >  fs/ntfs/inode.c          | 21 ++++++++++++---------
> >  fs/omfs/inode.c          |  4 ++++
> >  fs/orangefs/super.c      |  2 ++
> >  fs/pstore/ram.c          |  2 ++
> >  fs/qnx4/inode.c          |  2 ++
> >  fs/qnx6/inode.c          |  2 ++
> >  fs/reiserfs/super.c      |  3 +++
> >  fs/romfs/super.c         |  2 ++
> >  fs/squashfs/super.c      |  2 ++
> >  fs/super.c               |  2 ++
> >  fs/sysv/super.c          |  5 ++++-
> >  fs/ubifs/file.c          | 21 ++++++++++++---------
> >  fs/ufs/super.c           |  7 +++++++
> >  fs/utimes.c              |  6 ++----
> >  fs/xfs/xfs_super.c       |  2 ++
> >  include/linux/fs.h       |  5 +++++
> >  include/linux/time64.h   |  2 ++
> >  48 files changed, 298 insertions(+), 72 deletions(-)


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits
  2019-08-30  1:20   ` Mike Marshall
@ 2019-08-30  2:02     ` Deepa Dinamani
  2019-08-30 13:58       ` Arnd Bergmann
  0 siblings, 1 reply; 5+ messages in thread
From: Deepa Dinamani @ 2019-08-30  2:02 UTC (permalink / raw)
  To: Mike Marshall
  Cc: Latchesar Ionkov, Martin Brandenburg, jfs-discussion,
	Dave Kleikamp, al, Bob Copeland, Adrian Hunter, Andreas Dilger,
	mikulas, stoph Hellwig, nico, linux-cifs, Yan, Zheng, Sage Weil,
	Darrick J. Wong, y2038 Mailman List, Richard Weinberger,
	Steve French, Anton Vorontsov, linux, codalist,
	Christoph Hellwig, coda, V9FS Developers, Ilya Dryomov,
	Ext4 Developers List, salah.triki, asmadeus, devel,
	Evgeniy Dushistov, Kees Cook, Arnd Bergmann, Eric Van Hensbergen,
	Jan Kara, reiserfs-devel, Tejun Heo, Alexander Viro,
	aivazian.tigran, phillip, David Sterba, Jaegeuk Kim, ceph-devel,
	trond.myklebust, OGAWA Hirofumi, Andreas Dilger, Jan Harkes,
	Linux NFS Mailing List, Tony Luck, Theodore Ts'o, luisbg,
	Artem Bityutskiy, linux-ntfs-dev, Greg KH, linux-karma-devel,
	jlayton, Linux Kernel Mailing List, Linux F2FS DEV, Mailing List,
	linux-xfs, Colin Cross, Linux FS-devel Mailing List, linux-mtd,
	David Woodhouse, Anna Schumaker, Joel Becker

On Thu, Aug 29, 2019 at 6:20 PM Mike Marshall <hubcap@omnibond.com> wrote:
>
> Hi Deepa...
>
> I installed this patch series on top of Linux 5.3-rc6 and ran xfstests
> on orangefs and got a regression... generic/258 failed
> with: "Timestamp wrapped"...
>
> # cat results/generic/258.out.bad
> QA output created by 258
> Creating file with timestamp of Jan 1, 1960
> Testing for negative seconds since epoch
> Timestamp wrapped: 0
> Timestamp wrapped
> (see /home/hubcap/xfstests-dev/results//generic/258.full for details)

Note that patch [16/20] https://lkml.org/lkml/2019/8/18/193 assumes
that orangefs does not support negative timestamps.
And, the reason was pointed out in the commit text:

----------------------
Assume the limits as unsigned according to the below
commit 98e8eef557a9 ("changed PVFS_time from int64_t to uint64_t")
in https://github.com/waltligon/orangefs

Author: Neill Miller <neillm@mcs.anl.gov>
Date:   Thu Sep 2 15:00:38 2004 +0000
--------------------

So the timestamp being wrapped to 0 in this case is correct behavior
according to my patchset.
The generic/258 assumes that the timestamps can be negative. If this
is not true then it should not be run for this fs.

But, if you think the timestamp should support negative timestamps for
orangefs, I'd be happy to change it.

> Just to double check, I compiled Linux 5.3-rc6 without the timestamp series,
> and 258 passed... then added the patch series back and the failure returned...
>
> Also.... when I was using "git am" to apply the patch series, the ceph patch
> failed, so I "git skipped" it...

My series applies cleanly against linux-next as of yesterday.

-Deepa


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits
  2019-08-30  2:02     ` Deepa Dinamani
@ 2019-08-30 13:58       ` Arnd Bergmann
  2019-08-31 22:50         ` Deepa Dinamani
  0 siblings, 1 reply; 5+ messages in thread
From: Arnd Bergmann @ 2019-08-30 13:58 UTC (permalink / raw)
  To: Deepa Dinamani
  Cc: Latchesar Ionkov, Martin Brandenburg, jfs-discussion,
	Dave Kleikamp, Anders Larsen, Bob Copeland, Adrian Hunter,
	Andreas Dilger, mikulas, stoph Hellwig, Nicolas Pitre,
	Mike Marshall, linux-cifs, Yan, Zheng, Sage Weil,
	Darrick J. Wong, y2038 Mailman List, Richard Weinberger,
	Steve French, Anton Vorontsov, Russell King - ARM Linux,
	codalist, Christoph Hellwig, coda, V9FS Developers, Ilya Dryomov,
	Ext4 Developers List, salah.triki, asmadeus, devel,
	Evgeniy Dushistov, Kees Cook, Eric Van Hensbergen, Jan Kara,
	reiserfs-devel, Tejun Heo, Alexander Viro, aivazian.tigran,
	phillip, David Sterba, Jaegeuk Kim, ceph-devel, trond.myklebust,
	OGAWA Hirofumi, Andreas Dilger, Jan Harkes,
	Linux NFS Mailing List, Tony Luck, Theodore Ts'o,
	Luis de Bethencourt, Artem Bityutskiy, linux-ntfs-dev, Greg KH,
	linux-karma-devel, Jeff Layton, Linux Kernel Mailing List,
	Linux F2FS DEV, Mailing List, linux-xfs, Colin Cross,
	Linux FS-devel Mailing List, linux-mtd, David Woodhouse,
	Anna Schumaker, Joel Becker

On Fri, Aug 30, 2019 at 4:02 AM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> On Thu, Aug 29, 2019 at 6:20 PM Mike Marshall <hubcap@omnibond.com> wrote:
> >
> > Hi Deepa...
> >
> > I installed this patch series on top of Linux 5.3-rc6 and ran xfstests
> > on orangefs and got a regression... generic/258 failed
> > with: "Timestamp wrapped"...
> >
> > # cat results/generic/258.out.bad
> > QA output created by 258
> > Creating file with timestamp of Jan 1, 1960
> > Testing for negative seconds since epoch
> > Timestamp wrapped: 0
> > Timestamp wrapped
> > (see /home/hubcap/xfstests-dev/results//generic/258.full for details)
>
> Note that patch [16/20] https://lkml.org/lkml/2019/8/18/193 assumes
> that orangefs does not support negative timestamps.
> And, the reason was pointed out in the commit text:
>
> ----------------------
> Assume the limits as unsigned according to the below
> commit 98e8eef557a9 ("changed PVFS_time from int64_t to uint64_t")
> in https://github.com/waltligon/orangefs
>
> Author: Neill Miller <neillm@mcs.anl.gov>
> Date:   Thu Sep 2 15:00:38 2004 +0000
> --------------------
>
> So the timestamp being wrapped to 0 in this case is correct behavior
> according to my patchset.
> The generic/258 assumes that the timestamps can be negative. If this
> is not true then it should not be run for this fs.
>
> But, if you think the timestamp should support negative timestamps for
> orangefs, I'd be happy to change it.

I think it's unclear from the orangefs source code what the intention is,
as there is a mixed of signed and unsigned types used for the inode
stamps:

#define encode_PVFS_time encode_int64_t
#define encode_int64_t(pptr,x) do { \
    *(int64_t*) *(pptr) = cpu_to_le64(*(x)); \
    *(pptr) += 8; \
} while (0)
#define decode_PVFS_time decode_int64_t
#define decode_int64_t(pptr,x) do { \
    *(x) = le64_to_cpu(*(int64_t*) *(pptr)); \
    *(pptr) += 8; \
} while (0)

This suggests that making it unsigned may have been an accident.

Then again,  it's clearly and consistently printed as unsigned in
user space:

        gossip_debug(
            GOSSIP_GETATTR_DEBUG, " VERSION is %llu, mtime is %llu\n",
            llu(s_op->attr.mtime), llu(resp_attr->mtime));

A related issue I noticed is this:

PVFS_time PINT_util_mktime_version(PVFS_time time)
{
    struct timeval t = {0,0};
    PVFS_time version = (time << 32);

    gettimeofday(&t, NULL);
    version |= (PVFS_time)t.tv_usec;
    return version;
}
PVFS_time PINT_util_mkversion_time(PVFS_time version)
{
    return (PVFS_time)(version >> 32);
}
static PINT_sm_action getattr_verify_attribs(
        struct PINT_smcb *smcb, job_status_s *js_p)
{
...
    resp_attr->mtime = PINT_util_mkversion_time(s_op->attr.mtime);
...
}

which suggests that at least for some purposes, the mtime field
is only an unsigned 32-bit number (1970..2106). From my readiing,
this affects the on-disk format, but not the protocol implemented
by the kernel.

atime and ctime are apparently 64-bit, but mtime is only 32-bit
seconds, plus a 32-bit 'version'. I suppose the server could be
fixed to allow a larger range, but probably would take it out of
the 'version' bits, not the upper half.

To be on the safe side, I suppose the kernel can only assume
an unsigned 32-bit range to be available. If the server gets
extended beyond that, it would have to pass a feature flag.

     Arnd


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Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits
  2019-08-30 13:58       ` Arnd Bergmann
@ 2019-08-31 22:50         ` Deepa Dinamani
  0 siblings, 0 replies; 5+ messages in thread
From: Deepa Dinamani @ 2019-08-31 22:50 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Latchesar Ionkov, Martin Brandenburg, jfs-discussion,
	Dave Kleikamp, Anders Larsen, Bob Copeland, Adrian Hunter,
	Andreas Dilger, mikulas, stoph Hellwig, Nicolas Pitre,
	Mike Marshall, linux-cifs, Yan, Zheng, Sage Weil,
	Darrick J. Wong, y2038 Mailman List, Richard Weinberger,
	Steve French, Anton Vorontsov, Russell King - ARM Linux,
	codalist, Christoph Hellwig, coda, V9FS Developers, Ilya Dryomov,
	Ext4 Developers List, salah.triki, asmadeus, devel,
	Evgeniy Dushistov, Kees Cook, Eric Van Hensbergen, Jan Kara,
	reiserfs-devel, Tejun Heo, Alexander Viro, aivazian.tigran,
	phillip, David Sterba, Jaegeuk Kim, ceph-devel, trond.myklebust,
	OGAWA Hirofumi, Andreas Dilger, Jan Harkes,
	Linux NFS Mailing List, Tony Luck, Theodore Ts'o,
	Luis de Bethencourt, Artem Bityutskiy, linux-ntfs-dev, Greg KH,
	linux-karma-devel, Jeff Layton, Linux Kernel Mailing List,
	Linux F2FS DEV, Mailing List, linux-xfs, Colin Cross,
	Linux FS-devel Mailing List, linux-mtd, David Woodhouse,
	Anna Schumaker, Joel Becker

> I think it's unclear from the orangefs source code what the intention is,
> as there is a mixed of signed and unsigned types used for the inode
> stamps:
>
> #define encode_PVFS_time encode_int64_t
> #define encode_int64_t(pptr,x) do { \
>     *(int64_t*) *(pptr) = cpu_to_le64(*(x)); \
>     *(pptr) += 8; \
> } while (0)
> #define decode_PVFS_time decode_int64_t
> #define decode_int64_t(pptr,x) do { \
>     *(x) = le64_to_cpu(*(int64_t*) *(pptr)); \
>     *(pptr) += 8; \
> } while (0)
>
> This suggests that making it unsigned may have been an accident.
>
> Then again,  it's clearly and consistently printed as unsigned in
> user space:
>
>         gossip_debug(
>             GOSSIP_GETATTR_DEBUG, " VERSION is %llu, mtime is %llu\n",
>             llu(s_op->attr.mtime), llu(resp_attr->mtime));

I think I had noticed these two and decided maybe the intention was to
use unsigned types.

> A related issue I noticed is this:
>
> PVFS_time PINT_util_mktime_version(PVFS_time time)
> {
>     struct timeval t = {0,0};
>     PVFS_time version = (time << 32);
>
>     gettimeofday(&t, NULL);
>     version |= (PVFS_time)t.tv_usec;
>     return version;
> }
> PVFS_time PINT_util_mkversion_time(PVFS_time version)
> {
>     return (PVFS_time)(version >> 32);
> }
> static PINT_sm_action getattr_verify_attribs(
>         struct PINT_smcb *smcb, job_status_s *js_p)
> {
> ...
>     resp_attr->mtime = PINT_util_mkversion_time(s_op->attr.mtime);
> ...
> }
>
> which suggests that at least for some purposes, the mtime field
> is only an unsigned 32-bit number (1970..2106). From my readiing,
> this affects the on-disk format, but not the protocol implemented
> by the kernel.
>
> atime and ctime are apparently 64-bit, but mtime is only 32-bit
> seconds, plus a 32-bit 'version'. I suppose the server could be
> fixed to allow a larger range, but probably would take it out of
> the 'version' bits, not the upper half.

I had missed this part. Thanks.

> To be on the safe side, I suppose the kernel can only assume
> an unsigned 32-bit range to be available. If the server gets
> extended beyond that, it would have to pass a feature flag.

This makes sense to me also. And, as Arnd pointed out on the IRC, if
there are negative timestamps that are already in use, this will be a
problem for those use cases.
I can update tha patch to use limits 0-u32_max.

-Deepa


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^ permalink raw reply	[flat|nested] 5+ messages in thread

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Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <20190829041132.26677-1-deepa.kernel@gmail.com>
2019-08-29  4:38 ` [f2fs-dev] [GIT PULL] vfs: Add support for timestamp limits Deepa Dinamani
2019-08-30  1:20   ` Mike Marshall
2019-08-30  2:02     ` Deepa Dinamani
2019-08-30 13:58       ` Arnd Bergmann
2019-08-31 22:50         ` Deepa Dinamani

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