linux-kernel - Re: [PATCH] ext4/060: Skip for dax devices on non-4k page sizes

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Message-ID: <20251012195731.GG354523@mit.edu>
Date: Sun, 12 Oct 2025 15:57:31 -0400
From: "Theodore Ts'o" <tytso@....edu>
To: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
Cc: Zorro Lang <zlang@...hat.com>, fstests@...r.kernel.org,
        srivathsa.d.dara@...cle.com, linux-kernel@...r.kernel.org,
        Disha Goel <disgoel@...ux.ibm.com>
Subject: Re: [PATCH] ext4/060: Skip for dax devices on non-4k page sizes

On Sat, Oct 11, 2025 at 07:17:08PM +0530, Ojaswin Mujoo wrote:
> This test tries to trigger an ext4 corruption by resizing past the
> meta_bg size (8GB on 4k blocksize) in ext4. Since the test is sensistive
> to the size and FS layout it hardcodes the 4kb blocksize ignoring user's
> $MKFS_OPTIONS. While this is okay for most cases it fails for dax based
> filesystems where system pagesize is non-4k.
> 
> One way to work past this is to make the test blocksize agnostic, but
> since we still need the disk to be as big as the meta_bg size, this
> means for blocksize=64kb filesystems we need a scratch disk of ~4TB
> which is not feasible.
> 
> Hence, just skip the test if fsdax is used in a non-4k page size system.
> 
> Reported-by: Disha Goel <disgoel@...ux.ibm.com>
> Signed-off-by: Ojaswin Mujoo <ojaswin@...ux.ibm.com>

Makes sense to me.

Reviewed-by: Theodore Ts'o <tytso@....edu>