More on quotas

[Jim McDonough]

Jeremy Allison wrote,
>At what point in the above sequence does it issue the zero
>byte write ? Is that the "set the new file size" call you
>mean, or is it before or after that ? This is important,
>as I can easily catch this zero size write and cause the
>real filesize to be extended - although there's an inherent
>race condition w.r.t. other apps extending the file at the
>same time.

Ok, I'll summarize less this time.  NT doesn't issue this zero byte write
to a samba server, presumably because some previous request failed (a
transact2 query file info failed because of unsupported level 0x109.  The
following summary is from an NT client to a 2k server:

C transact2 Query path info, File = \home\jmcd\oldfile
R transact2 (Unknown) (response)
C check path, File = \home\jmcd
R check path
C transact2 Findfirst, File = \home\jmcd\oldfile
R transact2 (Unknown) (response)
C NT create & X, File = home\jmcd\oldfile
R NT create & X, FID = 0x112d
C read & X, FID = 0x112d, Read 0x1000 at 0x000000
R read & X, Read 0x1000
R read & X, Read 0x1000
C transact2 Query path info, File = \newfile
R transact2 - NT error, System, Error, Code = (52
C NT create & X, File = home\jmcd\oldfile
C lock & X, FID = 0x112d, Unlocks = 0 (0x4e for 0
C lock & X, FID = 0x112d, Unlocks = 0 (0x4e for 0
R NT create & X, FID = 0x112e
C transact2 Query file info, FID = 0x112e
R transact2 Open (response)
C transact2 Query file info, FID = 0x112e
R transact2 (Unknown) (response)
C transact2 Query file info, FID = 0x112e
R transact2 Open (response)
C NT create & X, File = \newfile
R NT create & X, FID = 0x4000
C write, FID = 0x4000, Write 0x0 at 0x27736000  <<<<<<here's the zero byte
write that doesn't occur from samba
R write - NT error, System, Error, Code = (127) S
C transact2 Query file info, FID = 0x4000
R transact2 (Unknown) (response)
C transact2 Set file info, FID = 0x4000
R transact2 (Unknown) (response)
C close file, FID = 0x4000
R close file
C close file, FID = 0x112e
R close file
C close file, FID = 0x112d
R close file

----------------------------
Jim McDonough
Linux Technology Center
IBM Boulder

Notes: Jim McDonough/Boulder/IBM @ IBMUS
VNET: JMCD at IBMUSM54
Internet: jmcd at us.ibm.com

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