From nobody Thu Oct 9 10:06:06 2025
Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171])
(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
(No client certificate requested)
by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC1C2202F70;
Wed, 18 Jun 2025 09:17:25 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org;
arc=none smtp.client-ip=80.241.56.171
ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
t=1750238247; cv=none;
b=Dy9/VYuGIYVqRxC8EdWsBPn6z3inTtKaNlucns71HRiGIpEKFqs1n7Zc6NdM0HAmPlKWFftEFEnhGTaNoiAJqexGKNOIeyi7NvYdfms9aZhk0px+18YmusV7oe07sr9QFQn6XW1NtrnsA9sP1EzGhoDWHWbSiq3gfRjWiA+eK3A=
ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org;
s=arc-20240116; t=1750238247; c=relaxed/simple;
bh=4guzzl8+uPUhHITQeQqcp6+BE4ne+X0iPtJ7/i9d4V8=;
h=From:To:Cc:Subject:Date:Message-ID:MIME-Version;
b=NMi5O6PSJtvSrzDfU8BEXo2G2dA5EJkx9y9uTk8fbzbIfCsYdW1gOcRazYC9DQ3JiH2sN/dI3Drxj9yp3Dlc23xNcKxMJdaqynqrAaZ+UT8lZMHT09R6Nvrrw5TaaTi3+Zi4HId2Rxp5azRmDE8g7aXBt0gEClIZ8V1vNymFkKs=
ARC-Authentication-Results: i=1; smtp.subspace.kernel.org;
dmarc=fail (p=none dis=none) header.from=samsung.com;
spf=pass smtp.mailfrom=pankajraghav.com;
arc=none smtp.client-ip=80.241.56.171
Authentication-Results: smtp.subspace.kernel.org;
dmarc=fail (p=none dis=none) header.from=samsung.com
Authentication-Results: smtp.subspace.kernel.org;
spf=pass smtp.mailfrom=pankajraghav.com
Received: from smtp1.mailbox.org (smtp1.mailbox.org [10.196.197.1])
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest
SHA256)
(No client certificate requested)
by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4bMdRc1fpdz9tG4;
Wed, 18 Jun 2025 11:17:16 +0200 (CEST)
From: Pankaj Raghav
To: Alexander Viro ,
Jan Kara ,
mcgrof@kernel.org,
Christian Brauner
Cc: linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org,
gost.dev@samsung.com,
kernel@pankajraghav.com,
Pankaj Raghav
Subject: [PATCH] fs/buffer: use min folio order to calculate upper limit in
__getblk_slow()
Date: Wed, 18 Jun 2025 11:17:10 +0200
Message-ID: <20250618091710.119946-1-p.raghav@samsung.com>
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id:
List-Subscribe:
List-Unsubscribe:
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="utf-8"
The maximum IO size that a block device can read as a single block is
based on the min folio order and not the PAGE_SIZE as we have bs > ps
support for block devices[1].
Calculate the upper limit based on the on min folio order.
[1] https://lore.kernel.org/linux-block/20250221223823.1680616-1-mcgrof@ker=
nel.org/
Signed-off-by: Pankaj Raghav
Reviewed-by: Jan Kara
---
I found this while I was adding bs > ps support to ext4. Ext4 uses this
routine to read the superblock.
fs/buffer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 8cf4a1dc481e..98f90da69a0a 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1121,10 +1121,11 @@ __getblk_slow(struct block_device *bdev, sector_t b=
lock,
unsigned size, gfp_t gfp)
{
bool blocking =3D gfpflags_allow_blocking(gfp);
+ int blocklog =3D PAGE_SHIFT + mapping_min_folio_order(bdev->bd_mapping);
=20
/* Size must be multiple of hard sectorsize */
- if (unlikely(size & (bdev_logical_block_size(bdev)-1) ||
- (size < 512 || size > PAGE_SIZE))) {
+ if (unlikely(size & (bdev_logical_block_size(bdev) - 1) ||
+ (size < 512 || size > (1U << blocklog)))) {
printk(KERN_ERR "getblk(): invalid block size %d requested\n",
size);
printk(KERN_ERR "logical block size: %d\n",
base-commit: e04c78d86a9699d136910cfc0bdcf01087e3267e
--=20
2.49.0