From: Christoph Hellwig <hch@infradead.org>
To: Zhang Yi <yi.zhang@huaweicloud.com>
Cc: Lukas Herbolt <lukas@herbolt.com>,
Christoph Hellwig <hch@infradead.org>,
djwong@kernel.org, linux-xfs@vger.kernel.org,
Zhang Yi <yi.zhang@huawei.com>
Subject: Re: [PATCH] xfs: add FALLOC_FL_WRITE_ZEROES to XFS code base
Date: Wed, 22 Oct 2025 00:15:23 -0700 [thread overview]
Message-ID: <aPiEi2onSUfAPSdM@infradead.org> (raw)
In-Reply-To: <f90b0e3e-7734-4e86-8c73-011e71333272@huaweicloud.com>
On Wed, Oct 22, 2025 at 03:13:38PM +0800, Zhang Yi wrote:
> This situation will be intercepted in vfs_fallcoate().
Ah, perfect.
> Besides, it seems that the comments for the xfs_falloc_zero_range() also
> need to be updated. Specifically, for inodes that are always COW, there
> is no difference between FALLOC_FL_WRITE_ZEROES and FALLOC_FL_ZERO_RANGE
> because it does not create zeroed extents.
In fact we should not offer FALLOC_FL_WRITE_ZEROES for always COW
inodes. Yes, you can physically write zeroes if the hardware supports
it, but given that any overwrite will cause and allocation anyway it
will just increase the write amplification for no gain.
next prev parent reply other threads:[~2025-10-22 7:15 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-21 14:17 [PATCH 0/2] Add FL_WRITE_ZEROES to XFS, fix krealloc on xfs_uuid_table Lukas Herbolt
2025-10-21 14:17 ` [PATCH] xfs: add FALLOC_FL_WRITE_ZEROES to XFS code base Lukas Herbolt
2025-10-21 15:55 ` Darrick J. Wong
2025-10-22 5:00 ` Christoph Hellwig
2025-10-22 7:13 ` Zhang Yi
2025-10-22 7:15 ` Christoph Hellwig [this message]
2025-10-22 7:27 ` Zhang Yi
2025-10-29 17:53 ` [PATCH v3] " Lukas Herbolt
2025-10-29 18:22 ` Darrick J. Wong
2025-10-30 7:27 ` Christoph Hellwig
2025-11-12 21:02 ` [PATCH v4] " Lukas Herbolt
2025-11-13 6:59 ` Christoph Hellwig
2025-11-14 8:55 ` [PATCH v5] " Lukas Herbolt
2025-11-14 8:57 ` Christoph Hellwig
2025-11-14 16:44 ` Darrick J. Wong
2025-11-14 16:45 ` Christoph Hellwig
2025-11-18 9:05 ` lukas
2025-12-15 11:48 ` [PATCH v6] " Lukas Herbolt
2025-12-15 14:28 ` Christoph Hellwig
2025-10-30 7:29 ` [PATCH v3] " Christoph Hellwig
2025-10-21 14:17 ` [PATCH 2/2] xfs: Remove WARN_ONCE if xfs_uuid_table grows over 2x PAGE_SIZE Lukas Herbolt
2025-10-21 15:56 ` Darrick J. Wong
2025-10-21 22:02 ` Dave Chinner
2025-10-26 17:49 ` lukas
2025-10-22 4:53 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2026-02-12 13:12 [PATCH] xfs: add FALLOC_FL_WRITE_ZEROES to XFS code base Lukas Herbolt
2026-02-12 13:15 ` Lukas Herbolt
2026-02-25 8:37 Lukas Herbolt
2026-02-25 8:41 ` Lukas Herbolt
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