From nobody Mon Feb 9 14:15:20 2026 Received: from fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com (fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com [3.64.237.68]) (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 93BB625D540; Tue, 21 Oct 2025 07:13:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.64.237.68 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761030790; cv=none; b=q8AX6M2lA9qJQFVkpMPaMJu1mCNUzSfCbnGOUdQ0IptHpP5hm19rjDSuQYELpGR0g2lI77+prFplQ7fHNAtEJuk4iWZB8fofTP16ZNlPTolZ35jXBse1V//HEeZ/66DSi9EOi3mTYkL5gcMcv1hhUYldspp6kkwopOT44ohwz9I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761030790; c=relaxed/simple; bh=YYP+JvL1Azmf39UNxyLGq9iTQvod6ds7wDUTSE8XiV4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mANOf2I/adJ3RK0mightC62I+YHhDWpXs99XVYEd6lzctln/mdcQ0MeIFDvO/Pdv0TBdJ2kqyHQwwnL26/wUyu15btV060PEP9FhSjjZj9GBux+jHrsZyfRNzPSd3cEVsYTJq1R2MnFmaoduQFjvcNw/EZTru7nTaDfYew4lV0w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.de; spf=pass smtp.mailfrom=amazon.de; dkim=pass (2048-bit key) header.d=amazon.de header.i=@amazon.de header.b=ZFYESqTi; arc=none smtp.client-ip=3.64.237.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.de header.i=@amazon.de header.b="ZFYESqTi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazoncorp2; t=1761030788; x=1792566788; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JG6/21Kc3LPmm7ifFU0zEa7/qVfomGnzIkk8iphJ08Q=; b=ZFYESqTis0Cp8Ld/BdgJrwAS7Y6xqQIo5/P0c4kFTT3BPHa3kHCGZPm3 3VqqweZuZTlQpC/Y7lipA6uFG+gY+O4NKr3Q0BSyMrv3//GR2NdIGE7U5 23qj2egJCXzUn9G8zJtR1BV0MJz4a1UVGM0tJFPwwD4RXd8qFJjZLBEKk cCf3rg11OJYRtoK9QTDfSdoVilAY7cnIzjyeUV2gPD0Wr58OwuhlDnip9 8fFtABBR6m1CrXMY7itaGZfEFjI+WZ8VfrH340ODVjnX2b3wfXIx1T6Bs GOMhN3eRhFSBUBaka6JliQY6q9xZFFiwHk8BwEDup6FnkVRc59ARIYapa Q==; X-CSE-ConnectionGUID: 9ajDuW3IRAqJTQOmqwROGg== X-CSE-MsgGUID: w3M+VODYSFGUxfTSLykcsw== X-IronPort-AV: E=Sophos;i="6.19,244,1754956800"; d="scan'208";a="3832773" Received: from ip-10-6-3-216.eu-central-1.compute.internal (HELO smtpout.naws.eu-central-1.prod.farcaster.email.amazon.dev) ([10.6.3.216]) by internal-fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Oct 2025 07:12:56 +0000 Received: from EX19MTAEUC002.ant.amazon.com [54.240.197.228:1068] by smtpin.naws.eu-central-1.prod.farcaster.email.amazon.dev [10.0.47.14:2525] with esmtp (Farcaster) id 1553515b-eb11-4da4-8ddb-b9d47464950e; Tue, 21 Oct 2025 07:12:56 +0000 (UTC) X-Farcaster-Flow-ID: 1553515b-eb11-4da4-8ddb-b9d47464950e Received: from EX19D013EUB004.ant.amazon.com (10.252.51.92) by EX19MTAEUC002.ant.amazon.com (10.252.51.245) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Tue, 21 Oct 2025 07:12:55 +0000 Received: from dev-dsk-mngyadam-1c-cb3f7548.eu-west-1.amazon.com (10.253.107.175) by EX19D013EUB004.ant.amazon.com (10.252.51.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Tue, 21 Oct 2025 07:12:46 +0000 From: Mahmoud Adam To: CC: , , Ryusuke Konishi , , , Andrew Morton , Jens Axboe , Xiubo Li , Ilya Dryomov , Jeff Layton , Alexander Viro , Theodore Ts'o , Andreas Dilger , Jaegeuk Kim , Chao Yu , Christoph Hellwig , "Darrick J. Wong" , Trond Myklebust , Anna Schumaker , "Matthew Wilcox (Oracle)" , Hannes Reinecke , Damien Le Moal , Luis Chamberlain , , , , , , , , , , Subject: [PATCH 6.1 8/8] nilfs2: fix deadlock warnings caused by lock dependency in init_nilfs() Date: Tue, 21 Oct 2025 09:03:43 +0200 Message-ID: <20251021070353.96705-10-mngyadam@amazon.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251021070353.96705-2-mngyadam@amazon.de> References: <20251021070353.96705-2-mngyadam@amazon.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D036UWC002.ant.amazon.com (10.13.139.242) To EX19D013EUB004.ant.amazon.com (10.252.51.92) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Ryusuke Konishi commit fb881cd7604536b17a1927fb0533f9a6982ffcc5 upstream. After commit c0e473a0d226 ("block: fix race between set_blocksize and read paths") was merged, set_blocksize() called by sb_set_blocksize() now locks the inode of the backing device file. As a result of this change, syzbot started reporting deadlock warnings due to a circular dependency involving the semaphore "ns_sem" of the nilfs object, the inode lock of the backing device file, and the locks that this inode lock is transitively dependent on. This is caused by a new lock dependency added by the above change, since init_nilfs() calls sb_set_blocksize() in the lock section of "ns_sem". However, these warnings are false positives because init_nilfs() is called in the early stage of the mount operation and the filesystem has not yet started. The reason why "ns_sem" is locked in init_nilfs() was to avoid a race condition in nilfs_fill_super() caused by sharing a nilfs object among multiple filesystem instances (super block structures) in the early implementation. However, nilfs objects and super block structures have long ago become one-to-one, and there is no longer any need to use the semaphore there. So, fix this issue by removing the use of the semaphore "ns_sem" in init_nilfs(). Link: https://lkml.kernel.org/r/20250503053327.12294-1-konishi.ryusuke@gmai= l.com Fixes: c0e473a0d226 ("block: fix race between set_blocksize and read paths") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+00f7f5b884b117ee6773@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3D00f7f5b884b117ee6773 Tested-by: syzbot+00f7f5b884b117ee6773@syzkaller.appspotmail.com Reported-by: syzbot+f30591e72bfc24d4715b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3Df30591e72bfc24d4715b Tested-by: syzbot+f30591e72bfc24d4715b@syzkaller.appspotmail.com> Signed-off-by: Andrew Morton Signed-off-by: Mahmoud Adam --- fs/nilfs2/the_nilfs.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c index be41e26b782469..05fdbbc63e1f5f 100644 --- a/fs/nilfs2/the_nilfs.c +++ b/fs/nilfs2/the_nilfs.c @@ -680,8 +680,6 @@ int init_nilfs(struct the_nilfs *nilfs, struct super_bl= ock *sb, char *data) int blocksize; int err; =20 - down_write(&nilfs->ns_sem); - blocksize =3D sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); if (!blocksize) { nilfs_err(sb, "unable to set blocksize"); @@ -757,7 +755,6 @@ int init_nilfs(struct the_nilfs *nilfs, struct super_bl= ock *sb, char *data) set_nilfs_init(nilfs); err =3D 0; out: - up_write(&nilfs->ns_sem); return err; =20 failed_sbh: --=20 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597