From: Florian Weimer <fweimer@redhat.com>
To: Hans Holmberg <hans.holmberg@wdc.com>
Cc: linux-xfs@vger.kernel.org, Carlos Maiolino <cem@kernel.org>,
Dave Chinner <david@fromorbit.com>,
"Darrick J . Wong" <djwong@kernel.org>,
Christoph Hellwig <hch@lst.de>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
libc-alpha@sourceware.org
Subject: Re: [RFC] xfs: fake fallocate success for always CoW inodes
Date: Thu, 06 Nov 2025 14:48:12 +0100 [thread overview]
Message-ID: <lhuikfngtlv.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20251106133530.12927-1-hans.holmberg@wdc.com> (Hans Holmberg's message of "Thu, 6 Nov 2025 14:35:30 +0100")
* Hans Holmberg:
> We don't support preallocations for CoW inodes and we currently fail
> with -EOPNOTSUPP, but this causes an issue for users of glibc's
> posix_fallocate[1]. If fallocate fails, posix_fallocate falls back on
> writing actual data into the range to try to allocate blocks that way.
> That does not actually gurantee anything for CoW inodes however as we
> write out of place.
Why doesn't fallocate trigger the copy instead? Isn't this what the
user is requesting?
Thanks,
Florian
next prev parent reply other threads:[~2025-11-06 13:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-06 13:35 [RFC] xfs: fake fallocate success for always CoW inodes Hans Holmberg
2025-11-06 13:48 ` Florian Weimer [this message]
2025-11-06 13:52 ` Christoph Hellwig
2025-11-06 14:42 ` Matthew Wilcox
2025-11-06 14:46 ` Christoph Hellwig
2025-11-11 8:31 ` Hans Holmberg
2025-11-11 9:05 ` hch
2025-11-11 9:50 ` Florian Weimer
2025-11-11 13:40 ` hch
2025-11-06 16:31 ` Florian Weimer
2025-11-06 17:05 ` Christoph Hellwig
2025-11-08 12:30 ` Florian Weimer
2025-11-09 22:15 ` Dave Chinner
2025-11-10 5:27 ` Florian Weimer
2025-11-10 9:38 ` Christoph Hellwig
2025-11-10 10:03 ` Florian Weimer
2025-11-10 20:28 ` Dave Chinner
2025-11-11 8:56 ` Christoph Hellwig
2025-11-10 9:37 ` Christoph Hellwig
2025-11-10 9:44 ` Florian Weimer
2025-11-10 21:33 ` Dave Chinner
2025-11-11 9:04 ` Christoph Hellwig
2025-11-11 9:30 ` Florian Weimer
2025-11-10 9:31 ` Christoph Hellwig
2025-11-10 9:48 ` truncatat? was, " Christoph Hellwig
2025-11-10 10:00 ` Florian Weimer
2025-11-10 9:49 ` Florian Weimer
2025-11-10 9:52 ` Christoph Hellwig
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