From patchwork Wed Apr 9 17:00:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 14045141 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BEA6B1C2324; Wed, 9 Apr 2025 17:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744218025; cv=none; b=I2GCSDUSLxB/g4Ohm6oyEmGykxGiu3fz7eZBjwBHTZi5aCue9k/yno3EcBxDjK4yFu/PJux9BTgHmNqi3YRfrMfPKBkPFl+Ln0i1dww8CAO6vb/O3u6fD8mkdYenmmCd91DSPBT8shWCdkMRieoPf4KTRyolWtbYi5baUfaaTa4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744218025; c=relaxed/simple; bh=iC/jQbcLbJDGJ+zTA6vNVqqv9zFp9l+WGsGwMEoqRNU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=RGL71ZdjZ7JWVc4QwVeGw02DU4yPZvK0JaO1r7mPLVN7PmI+zlEGQ3w9MZsnGYlu4mfXvktpYOo/40z30ElPXy8cPCLZ4oN/qqWvizIlnvBTWKM/qGh9Lrewdoo+x6C1rOwKAtuWi6UebOsNm2jiLZ5yueCe1JGf2e/wcCsaKY4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HpEpfeff; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HpEpfeff" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C77E5C4CEE7; Wed, 9 Apr 2025 17:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744218025; bh=iC/jQbcLbJDGJ+zTA6vNVqqv9zFp9l+WGsGwMEoqRNU=; h=From:To:Cc:Subject:Date:From; b=HpEpfeffs0T9WmcoEWY+75D8gY4v7Ki5VLqwmmemfvoIvZivHNDQALuwgDPIOxEca Kb7uxQrpUiM/Z7oK/xffQT7GfvPcEmeQZc40T2rfuNxLNM0yx/7OdflcWZL1qr0xt/ Zop96C9GDzXFzDg5Ee8vnmkJH94ngPCqaUNNQV163udZf4twIRzYD/02jS7PUejMP8 IBRKkZcIaxUn9pQWt94F7XLF0HbZESkQ9Ra28IFkM7qa0fkEZOnhDSNodyBAPQugFN 0BK7/uHvX93F0GOp7uDOp73rxY8nKLCBTVbWFxERpFAhcRtR52Er4+KR67NB7lcQLF dqTReI62Yj8WQ== From: Song Liu To: netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org Cc: dhowells@redhat.com, pc@manguebit.com, kernel-team@fb.com, Song Liu Subject: [PATCH v2] netfs: Only create /proc/fs/netfs with CONFIG_PROC_FS Date: Wed, 9 Apr 2025 10:00:15 -0700 Message-ID: <20250409170015.2651829-1-song@kernel.org> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When testing a special config: CONFIG_NETFS_SUPPORTS=y CONFIG_PROC_FS=n The system crashes with something like: [ 3.766197] ------------[ cut here ]------------ [ 3.766484] kernel BUG at mm/mempool.c:560! [ 3.766789] Oops: invalid opcode: 0000 [#1] SMP NOPTI [ 3.767123] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W [ 3.767777] Tainted: [W]=WARN [ 3.767968] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), [ 3.768523] RIP: 0010:mempool_alloc_slab.cold+0x17/0x19 [ 3.768847] Code: 50 fe ff 58 5b 5d 41 5c 41 5d 41 5e 41 5f e9 93 95 13 00 [ 3.769977] RSP: 0018:ffffc90000013998 EFLAGS: 00010286 [ 3.770315] RAX: 000000000000002f RBX: ffff888100ba8640 RCX: 0000000000000000 [ 3.770749] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 00000000ffffffff [ 3.771217] RBP: 0000000000092880 R08: 0000000000000000 R09: ffffc90000013828 [ 3.771664] R10: 0000000000000001 R11: 00000000ffffffea R12: 0000000000092cc0 [ 3.772117] R13: 0000000000000400 R14: ffff8881004b1620 R15: ffffea0004ef7e40 [ 3.772554] FS: 0000000000000000(0000) GS:ffff8881b5f3c000(0000) knlGS:0000000000000000 [ 3.773061] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3.773443] CR2: ffffffff830901b4 CR3: 0000000004296001 CR4: 0000000000770ef0 [ 3.773884] PKRU: 55555554 [ 3.774058] Call Trace: [ 3.774232] [ 3.774371] mempool_alloc_noprof+0x6a/0x190 [ 3.774649] ? _printk+0x57/0x80 [ 3.774862] netfs_alloc_request+0x85/0x2ce [ 3.775147] netfs_readahead+0x28/0x170 [ 3.775395] read_pages+0x6c/0x350 [ 3.775623] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.775928] page_cache_ra_unbounded+0x1bd/0x2a0 [ 3.776247] filemap_get_pages+0x139/0x970 [ 3.776510] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.776820] filemap_read+0xf9/0x580 [ 3.777054] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.777368] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.777674] ? find_held_lock+0x32/0x90 [ 3.777929] ? netfs_start_io_read+0x19/0x70 [ 3.778221] ? netfs_start_io_read+0x19/0x70 [ 3.778489] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.778800] ? lock_acquired+0x1e6/0x450 [ 3.779054] ? srso_alias_return_thunk+0x5/0xfbef5 [ 3.779379] netfs_buffered_read_iter+0x57/0x80 [ 3.779670] __kernel_read+0x158/0x2c0 [ 3.779927] bprm_execve+0x300/0x7a0 [ 3.780185] kernel_execve+0x10c/0x140 [ 3.780423] ? __pfx_kernel_init+0x10/0x10 [ 3.780690] kernel_init+0xd5/0x150 [ 3.780910] ret_from_fork+0x2d/0x50 [ 3.781156] ? __pfx_kernel_init+0x10/0x10 [ 3.781414] ret_from_fork_asm+0x1a/0x30 [ 3.781677] [ 3.781823] Modules linked in: [ 3.782065] ---[ end trace 0000000000000000 ]--- This is caused by the following error path in netfs_init(): if (!proc_mkdir("fs/netfs", NULL)) goto error_proc; Fix this by adding ifdef in netfs_main(), so that /proc/fs/netfs is only created with CONFIG_PROC_FS. Signed-off-by: Song Liu Acked-by: David Howells --- fs/netfs/main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/netfs/main.c b/fs/netfs/main.c index 4e3e62040831..70ecc8f5f210 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -127,11 +127,13 @@ static int __init netfs_init(void) if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0) goto error_subreqpool; +#ifdef CONFIG_PROC_FS if (!proc_mkdir("fs/netfs", NULL)) goto error_proc; if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, &netfs_requests_seq_ops)) goto error_procfile; +#endif #ifdef CONFIG_FSCACHE_STATS if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, netfs_stats_show)) @@ -144,9 +146,11 @@ static int __init netfs_init(void) return 0; error_fscache: +#ifdef CONFIG_PROC_FS error_procfile: remove_proc_subtree("fs/netfs", NULL); error_proc: +#endif mempool_exit(&netfs_subrequest_pool); error_subreqpool: kmem_cache_destroy(netfs_subrequest_slab);