From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C6428E87854 for ; Tue, 3 Feb 2026 18:30:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 126516B00A8; Tue, 3 Feb 2026 13:30:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0AB0B6B00AB; Tue, 3 Feb 2026 13:30:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E963F6B00B2; Tue, 3 Feb 2026 13:30:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id D0B356B00A8 for ; Tue, 3 Feb 2026 13:30:12 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 71814BA022 for ; Tue, 3 Feb 2026 18:30:12 +0000 (UTC) X-FDA: 84403985064.30.5A92224 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf23.hostedemail.com (Postfix) with ESMTP id D79A9140014 for ; Tue, 3 Feb 2026 18:30:09 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=BMp0LuU6; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="/jianvj6"; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=1xqZqDho; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ZGVRnDb4; spf=pass (imf23.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770143410; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=oUJSBz9YfynC+iGlMIj3lZdp588PvIwvXy4YD3LexCo=; b=m0Im05rGtUwKRYauTUOvZn/0OfUsScwkvtRsqlF/8MUhrWdqqAt1R2iHFl0h76nXYSVZAm RU6QPCIPPInzekT+dL/S/Yfm8Fgm+qo6g2GB2Jo1WAO8YxcRHOpCc6fPQh7+5FTDYhyDpo Zqj0XjeO2pBafiYYCK9bq5LjvpmMkv0= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=BMp0LuU6; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="/jianvj6"; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=1xqZqDho; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ZGVRnDb4; spf=pass (imf23.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770143410; a=rsa-sha256; cv=none; b=Mw2xeyONui/4A9saC8B7MWsQ8ZQ/4fI6J8pmL5XCvZTNiU6cJKuJXJSfLu2mHqi6Lr0C4p 5eP9DwyFPAUsrqjRTm8Ip7F7J0YuUglKjgwMvjGHITSQX57dNkKPIxpWuHsmEhGi18NXDY t7ZeL2zNJ6XS+d0/VY8jBA9kqxrCNO0= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (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 smtp-out1.suse.de (Postfix) with ESMTPS id E41443E6D0; Tue, 3 Feb 2026 18:30:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1770143408; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=oUJSBz9YfynC+iGlMIj3lZdp588PvIwvXy4YD3LexCo=; b=BMp0LuU6c7tESb/HwI8YWgpAgaqRM5VBaoTI6PpyN0hEz5nmO+0wBRFXL0LFTD4wf+qHav HFVzs0iDbjc/XPiPXKkTO1zWZClkqF2sH5FvInXKlmhvsGEjJQ8RuPD3QhRmVT1UYA7Tni Rd2jPvgI+blpt3ZXaDKFfCi17HJ2OMM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1770143408; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=oUJSBz9YfynC+iGlMIj3lZdp588PvIwvXy4YD3LexCo=; b=/jianvj6eZ6jroFLLEXpskoB0on5wdunnaNV675eJ7wsLUsBcK3tmtWPpjizl0wWmLefyw IPfUQFEQGp2DWyCA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1770143407; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=oUJSBz9YfynC+iGlMIj3lZdp588PvIwvXy4YD3LexCo=; b=1xqZqDhoroY+aWb+YP4sj8N2OVG7zUUNNQjcEDfMDroz2db8qqPhEd5RTMpB8ZzmWPsW8i yykjFFC9sRAtSIQzcwXcoc1g5j/hZbe5I2culWruG7Xc3pbo6OiF/2hlDg4pVI8tNvjiPv z/AJqvkwcLdwEd+i9yUq8ZGd5+PD5KQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1770143407; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=oUJSBz9YfynC+iGlMIj3lZdp588PvIwvXy4YD3LexCo=; b=ZGVRnDb4u8RrkKi2WfehmiHmUmk2lo4RNtEV2jf0cLif9mz7nx3rFYHFNCcIAP0Si240n4 Rx6uIlrZPg6ZeiBQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (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 imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id B6EF73EA62; Tue, 3 Feb 2026 18:30:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id IGVOLK8+gmkiJwAAD6G6ig (envelope-from ); Tue, 03 Feb 2026 18:30:07 +0000 Message-ID: Date: Tue, 3 Feb 2026 19:30:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [Kernel Bug] WARNING in mempool_alloc_noprof Content-Language: en-US To: Christoph Hellwig Cc: Harry Yoo , Vernon Yang , =?UTF-8?B?5p2O6b6Z5YW0?= , syzkaller@googlegroups.com, akpm@linux-foundation.org, cl@gentwo.org, rientjes@google.com, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net, Eric Biggers , "Theodore Y. Ts'o" , linux-fscrypt@vger.kernel.org References: <6f5881df-0e0b-4278-808b-7c0cffa12a30@suse.cz> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJnyBr8BQka0IFQAAoJECJPp+fMgqZkqmMQ AIbGN95ptUMUvo6aAdhxaOCHXp1DfIBuIOK/zpx8ylY4pOwu3GRe4dQ8u4XS9gaZ96Gj4bC+ jwWcSmn+TjtKW3rH1dRKopvC07tSJIGGVyw7ieV/5cbFffA8NL0ILowzVg8w1ipnz1VTkWDr 2zcfslxJsJ6vhXw5/npcY0ldeC1E8f6UUoa4eyoskd70vO0wOAoGd02ZkJoox3F5ODM0kjHu Y97VLOa3GG66lh+ZEelVZEujHfKceCw9G3PMvEzyLFbXvSOigZQMdKzQ8D/OChwqig8wFBmV QCPS4yDdmZP3oeDHRjJ9jvMUKoYODiNKsl2F+xXwyRM2qoKRqFlhCn4usVd1+wmv9iLV8nPs 2Db1ZIa49fJet3Sk3PN4bV1rAPuWvtbuTBN39Q/6MgkLTYHb84HyFKw14Rqe5YorrBLbF3rl M51Dpf6Egu1yTJDHCTEwePWug4XI11FT8lK0LNnHNpbhTCYRjX73iWOnFraJNcURld1jL1nV r/LRD+/e2gNtSTPK0Qkon6HcOBZnxRoqtazTU6YQRmGlT0v+rukj/cn5sToYibWLn+RoV1CE Qj6tApOiHBkpEsCzHGu+iDQ1WT0Idtdynst738f/uCeCMkdRu4WMZjteQaqvARFwCy3P/jpK uvzMtves5HvZw33ZwOtMCgbpce00DaET4y/UzsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZ8gcVAUJFhTonwAKCRAiT6fnzIKmZLY8D/9uo3Ut9yi2YCuASWxr7QQZ lJCViArjymbxYB5NdOeC50/0gnhK4pgdHlE2MdwF6o34x7TPFGpjNFvycZqccSQPJ/gibwNA zx3q9vJT4Vw+YbiyS53iSBLXMweeVV1Jd9IjAoL+EqB0cbxoFXvnjkvP1foiiF5r73jCd4PR rD+GoX5BZ7AZmFYmuJYBm28STM2NA6LhT0X+2su16f/HtummENKcMwom0hNu3MBNPUOrujtW khQrWcJNAAsy4yMoJ2Lw51T/5X5Hc7jQ9da9fyqu+phqlVtn70qpPvgWy4HRhr25fCAEXZDp xG4RNmTm+pqorHOqhBkI7wA7P/nyPo7ZEc3L+ZkQ37u0nlOyrjbNUniPGxPxv1imVq8IyycG AN5FaFxtiELK22gvudghLJaDiRBhn8/AhXc642/Z/yIpizE2xG4KU4AXzb6C+o7LX/WmmsWP Ly6jamSg6tvrdo4/e87lUedEqCtrp2o1xpn5zongf6cQkaLZKQcBQnPmgHO5OG8+50u88D9I rywqgzTUhHFKKF6/9L/lYtrNcHU8Z6Y4Ju/MLUiNYkmtrGIMnkjKCiRqlRrZE/v5YFHbayRD dJKXobXTtCBYpLJM4ZYRpGZXne/FAtWNe4KbNJJqxMvrTOrnIatPj8NhBVI0RSJRsbilh6TE m6M14QORSWTLRg== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Action: no action X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D79A9140014 X-Stat-Signature: 1deoof9nojqkumo76c7mhbt1trx5a8qm X-Rspam-User: X-HE-Tag: 1770143409-422912 X-HE-Meta: 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 SNQJIMnu 6G4uWjSE3a3OPfeZV7IcQEULueUoZuyLrqCuVrJM2GQuUOyVdMKq3XbbDX/S05zlqac/U5r2YsNs6Ye6MlzYIagmIk7XqbIKBHsDakfXBxA73bGcQCMTxXWmszgdrcgqk4YCOMG4ytWs6s5go2qVC/1xYpI0eq/4cuGdYz6ZnQm2UtPSCYri1GKYpuojP19x3Nz7V9hdvc7GbY11I/H8a3h7T/TrEIr+wMLq7mtemWZquJZ9Lp1qzetVyT6k6es06YpbMYAUgs73cgCbylZD7soQRs0Ub4la8p2sFFLW+ZYNvtrxm/6ldgl6jlLrwOq6y65aEuebrJa+Wlkw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/3/26 17:59, Christoph Hellwig wrote: > On Tue, Feb 03, 2026 at 05:55:27PM +0100, Vlastimil Babka wrote: >> On 2/3/26 17:27, Christoph Hellwig wrote: >> > On Tue, Feb 03, 2026 at 06:52:39PM +0900, Harry Yoo wrote: >> >> Maybe the changelog could be rephrased a bit, >> >> but overall LGTM, thanks! >> > >> > >> > No, that does not make sense. If mempool is used with __GFP_RECLAIM in >> > the flags it won't fail, and if it isn't, GFP_NOFAIL can't work. >> >> So that means as long as there's __GFP_RECLAIM, __GFP_NOFAIL isn't wrong, >> just redundant. > > Given how picky the rest of the mm is about __GFP_NOFAIL, silently > accepting it where it has no (or a weird and unexpected) effect > seems like a disservice to the users. OK then. But I don't think we need to add checks to the mempool hot paths. If somebody uses __GFP_NOFAIL, eventually it will trickle to the existing warning that triggered here. If it's using slab then eventually that will reach the page allocator too. Maybe not with some custom alloc functions, but meh. This f2fs_encrypt_one_page() case is weird though (and the relevant parts seem to be identical in current mainline). It uses GFP_NOFS, so __GFP_RECLAIM is there. It only adds __GFP_NOFAIL in case fscrypt_encrypt_pagecache_blocks() already failed with -ENOMEM. That means fscrypt_alloc_bounce_page() returns NULL, which is either the WARN_ON_ONCE(!fscrypt_bounce_page_pool) case (but the report doesn't include such a warning), or mempool_alloc() failed - but that shouldn't happen with GFP_NOFS? (Also the !fscrypt_bounce_page_pool is therefore an infinite retry loop, isn't it? Which would be truly a bug, unless I'm missing something.) Ah but fscrypt_encrypt_pagecache_blocks() can also return -ENOMEM due to fscrypt_crypt_data_unit() returning it. And there theoretically in v6.12.11 skcipher_request_alloc() could return -ENOMEM. In practice I assume this report was achieved by fault injection. But that possibility is gone with mainline commit 52e7e0d88933 ("fscrypt: Switch to sync_skcipher and on-stack requests") anyway. I think the whole "goto retry_encrypt;" loop in f2fs_encrypt_one_page() should just be removed.