From: Florian Weimer <fweimer@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: libc-alpha@sourceware.org, linux-fsdevel@vger.kernel.org,
Trond Myklebust <trondmy@hammerspace.com>
Subject: Re: posix_fallocate behavior in glibc
Date: Mon, 29 Jul 2024 21:23:22 +0200 [thread overview]
Message-ID: <8734nsj93p.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20240729190100.GA1664@lst.de> (Christoph Hellwig's message of "Mon, 29 Jul 2024 21:01:00 +0200")
* Christoph Hellwig:
> On Mon, Jul 29, 2024 at 08:52:00PM +0200, Florian Weimer wrote:
>> > supporting fallocate. That's is generally the wrong thing to do, and
>> > spectacularly wrong for file systems that write out of place.
>>
>> In this case, the file system could return another error code besides
>> EOPNOTSUPP.
>
> What error code would that be and how do applications know about it?
Anything that's not EOPNOTSUPP will do. EMEDIUMTYPE or ENOTBLK might do
it. Any of the many STREAMS error codes could also be re-used quite
safely because Linux doesn't do STREAMS.
If you remove the fallback code, applications need to be taught about
EOPNOTSUPP, so that doesn't really make a difference.
Still it needs testing. It's possible that key software doesn't expect
posix_fallocate to fail.
Thanks,
Florian
next prev parent reply other threads:[~2024-07-29 19:23 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-29 16:09 posix_fallocate behavior in glibc Christoph Hellwig
2024-07-29 17:23 ` Paul Eggert
2024-07-29 17:43 ` Christoph Hellwig
2024-07-29 17:54 ` Adhemerval Zanella Netto
[not found] ` <CAPBLoAf11hM0PLhqPG5gUyivU9U1manpOOhDWCPugUmWc1VVUw@mail.gmail.com>
2024-07-29 18:45 ` Christoph Hellwig
2024-07-29 17:57 ` Florian Weimer
2024-07-29 18:44 ` Christoph Hellwig
2024-07-29 18:52 ` Florian Weimer
2024-07-29 19:01 ` Christoph Hellwig
2024-07-29 19:23 ` Florian Weimer [this message]
2024-07-30 15:47 ` Christoph Hellwig
2024-07-30 16:11 ` Paul Eggert
2024-07-30 16:20 ` Christoph Hellwig
2024-07-30 17:03 ` Florian Weimer
2024-07-30 17:08 ` Christoph Hellwig
2024-07-30 17:29 ` Florian Weimer
2024-07-30 17:52 ` Mark Wielaard
2024-07-31 2:32 ` Theodore Ts'o
2024-07-29 23:53 ` Dave Chinner
-- strict thread matches above, loose matches on Subject: below --
2024-06-26 6:01 Christoph Hellwig
2024-07-29 15:09 ` Christoph Hellwig
2024-07-29 15:11 ` Sam James
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