Fwd: SMB2 not respecting mtime values
Steve French
smfrench at gmail.com
Thu Jun 13 20:55:57 UTC 2019
I verified that Jacob is correct. Works (mtime preserved) to Windows
10 server, but fails to Samba 4.10 server (mtime not preserved after
being set).
On Wed, Jun 12, 2019 at 11:19 AM Jacob Shivers <jshivers at redhat.com> wrote:
>
> I finally got around to making some time for this and I this is indeed
> a server side issue.
> The SMB client is using the appropriate file handles when setting
> atime and mtime and the server initially reports the desired mtime.
> The server only slightly later reports a mtime matching that of ctime.
>
> $ tshark -tad -n -r cp_p-testing-3.16.66.pcap -Y 'smb2.pid == 0xf2d'
> -T fields -e frame.number -e smb2.fid -e smb2.last_access.time -e
> smb2.last_write.time -e _ws.col.Info -E header=y | tr '\t' '#' |
> column -t -s '#'
> frame.number smb2.fid
> smb2.last_access.time smb2.last_write.time
> _ws.col.Info
> 170
> Create Request
> File: test_file-data
> 171
> Create
> Response, Error: STATUS_OBJECT_NAME_NOT_FOUND
> 173 00000000-0000-0000-0000-000000000000
> Create Request
> File: test_file-data
> 174 5981ad82-0000-0000-1d86-2dcf00000000 May 27, 2019
> 20:16:03.862513400 EDT May 27, 2019 20:16:03.862513400 EDT Create
> Response File: test_file-data
> 175 5981ad82-0000-0000-1d86-2dcf00000000
> GetInfo Request
> FILE_INFO/SMB2_FILE_INTERNAL_INFO File: test_file-data
> 176
> GetInfo
> Response
> 177 5981ad82-0000-0000-1d86-2dcf00000000
> Write Request
> Len:12 Off:0 File: test_file-data
> 178
> Write Response
> 179
> Create Request
> File: test_file-data
> 180 b8fa5b2d-0000-0000-d86e-38bf00000000 May 27, 2019
> 20:16:03.862513400 EDT May 27, 2019 20:16:03.862513400 EDT Create
> Response File: test_file-data
> 181 b8fa5b2d-0000-0000-d86e-38bf00000000 Oct 31, 2018
> 00:00:00.000000000 EDT Oct 31, 2018 00:00:00.000000000 EDT SetInfo
> Request FILE_INFO/SMB2_FILE_BASIC_INFO File: test_file-data
> 182
> SetInfo
> Response
> 183 b8fa5b2d-0000-0000-d86e-38bf00000000
> Close Request
> File: test_file-data
> 184 Dec 31, 1969
> 19:00:00.000000000 EST Dec 31, 1969 19:00:00.000000000 EST Close
> Response
> 185
> Create Request
> File: test_file-data
> 186 f7323833-0000-0000-5d04-6e1d00000000 Oct 31, 2018
> 00:00:00.000000000 EDT Oct 31, 2018 00:00:00.000000000 EDT Create
> Response File: test_file-data
> 187 f7323833-0000-0000-5d04-6e1d00000000 Dec 31, 1969
> 19:00:00.000000000 EST Dec 31, 1969 19:00:00.000000000 EST SetInfo
> Request FILE_INFO/SMB2_FILE_BASIC_INFO File: test_file-data
> 188
> SetInfo
> Response
> 189 f7323833-0000-0000-5d04-6e1d00000000
> Close Request
> File: test_file-data
> 190 Dec 31, 1969
> 19:00:00.000000000 EST Dec 31, 1969 19:00:00.000000000 EST Close
> Response
> 191 5981ad82-0000-0000-1d86-2dcf00000000
> Close Request
> File: test_file-data
> 192 Dec 31, 1969
> 19:00:00.000000000 EST Dec 31, 1969 19:00:00.000000000 EST Close
> Response
>
>
> $ tshark -tad -n -r cp_p-testing-3.16.66.pcap -Y 'smb2.cmd == find' -O
> smb2 | sed '/test_file-data/,/test_file-data/ !d'
> FileIdBothDirectoryInfo: test_file-data
> Next Offset: 0
> File Index: 0x00000000
> Create: May 27, 2019 20:16:03.862513400 EDT
> Last Access: Oct 31, 2018 00:00:00.000000000 EDT
> Last Write: May 27, 2019 20:16:03.872393500 EDT
> Last Change: May 27, 2019 20:16:03.872393500 EDT
> End Of File: 12
> Allocation Size: 1048576
> File Attributes: 0x00000020
> .... .... .... .... .... .... .... ...0 = Read
> Only: NOT read only
> .... .... .... .... .... .... .... ..0. = Hidden: NOT hidden
> .... .... .... .... .... .... .... .0.. = System:
> NOT a system file/dir
> .... .... .... .... .... .... .... 0... = Volume
> ID: NOT a volume ID
> .... .... .... .... .... .... ...0 .... =
> Directory: NOT a directory
> .... .... .... .... .... .... ..1. .... = Archive:
> Modified since last ARCHIVE
> .... .... .... .... .... .... .0.. .... = Device:
> NOT a device
> .... .... .... .... .... .... 0... .... = Normal:
> Has some attribute set
> .... .... .... .... .... ...0 .... .... =
> Temporary: NOT a temporary file
> .... .... .... .... .... ..0. .... .... = Sparse:
> NOT a sparse file
> .... .... .... .... .... .0.. .... .... = Reparse
> Point: Does NOT have an associated reparse point
> .... .... .... .... .... 0... .... .... =
> Compressed: Uncompressed
> .... .... .... .... ...0 .... .... .... = Offline: Online
> .... .... .... .... ..0. .... .... .... = Content
> Indexed: NOT content indexed
> .... .... .... .... .0.. .... .... .... =
> Encrypted: This is NOT an encrypted file
> Filename Length: 28
> EA Size: 60
> Reserved: 00000000
> File Id: 0x0000000000052b02
> Filename: test_file-data
>
> I've added additional notes, strace, and pcap data to both kenel and
> samba bugzillas that seem applicable to this:
>
> ** Bug 198967 - Modification times not preserved correctly **
> https://bugzilla.kernel.org/show_bug.cgi?id=198967
>
> ** Bug 13594 - smbd write time handling differs compared to recent
> Windows releases **
> https://bugzilla.samba.org/show_bug.cgi?id=13594
>
> The earlier comments about filehandle do not apply as the atime used
> the same filehandle and the filehandle used is what should be used for
> compound operations.
>
> For context, Samba is matching behavior in Windows 2k16.
>
>
> On Thu, Jan 24, 2019 at 5:49 PM Jeremy Allison <jra at samba.org> wrote:
> >
> > On Thu, Jan 24, 2019 at 05:47:24PM -0500, Jacob Shivers wrote:
> > > On Thu, Jan 24, 2019 at 3:14 PM Ralph Böhme <slow at samba.org> wrote:
> > > >
> > > > On Thu, Jan 24, 2019 at 12:24:53PM -0500, Jacob Shivers wrote:
> > > > >On Thu, Jan 24, 2019 at 12:11 PM Ralph Böhme via samba-technical
> > > > ><samba-technical at lists.samba.org> wrote:
> > > > >>
> > > > >> On Thu, Jan 24, 2019 at 09:03:41AM -0800, Jeremy Allison via samba-technical wrote:
> > > > >> >Maybe. Changing meta-data semantics on write is fraught with danger,
> > > > >> >and we don't even do that for SMB1 unix extensions. So let's not
> > > > >> >add contraints we don't understand yet please.
> > > > >> >
> > > > >> >My money is on a client bug, as always :-).
> > > > >>
> > > > >> fwiw, just in case you were not aware of this one:
> > > > >>
> > > > >> https://bugzilla.samba.org/show_bug.cgi?id=13594
> > > > >>
> > > > >> We also seem to have a bug that a set-eof on a handle with
> > > > >> set-eof-size=existing-size doesn't flush a pending write time update. At least
> > > > >> newer Windows server seem to do that.
> > > > >
> > > > >This seems like what the issue is.
> > > > >The SMB server is uptime mtime after the server actually flushes to
> > > > >stable storage.
> > > >
> > > > not quite, but still a client bug. :) The client uses a second handle to set the
> > > > mtime, it should use the first handle. Or open the second handle after closing
> > > > the first one where it did the write.
> > >
> > > Ahh.
> > >
> > > Thank you very much for your help and for narrowing down the problem
> > > to a client side bug :)
> >
> > Bingo ! I claim my 5 euro :-) :-).
--
Thanks,
Steve
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