Handling quota and out of space issues while holding an OpLock

[David Collier-Brown]

Am Sonntag, 19. September 2004 19:11 schrieb Richard Sharpe:
>>I have noticed that windows clients tend to send requests to extend the
>>file size even though they are holding an oplock on a file.
>>
>>It struck me that this must be so they can deal with issues like out of
>>quota or out of space at the point at which they occur  [...]

Peter Waechtler wrote:
 > [Discussion of checking writes]
> And with regards to quota: when does a unix system checks the quota limit?
> On Inode and block allocation time? Am I able to create a sparse file that is 
> beyond the limit - only getting an error on block allocation? I think so.

   Yes, that's correct: standard Unix discovers it's out of space/quota
only when it actually allocates the blocks of a "holey" file.

   This came up in discussions here before, but I don't recollect what
the resolution was. I do remember that space-filling was an expensive
operation (;-)).  The quota code is mostly by Stefan (metze)
Metzmacher...

--dave