From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4427226B95A for ; Wed, 30 Jul 2025 10:29:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753871349; cv=none; b=kAkSmlmFHaAXeEnFaUqrWs+32tMQTSiTV+rwHp75VNAu9bjm0cMa8+GbaqQC79eTgPczlsa2wISbfo5LPd3VuGpMoCIHA6aW0u8YO2KFCpWjCqVyGzqpM8CgMAyaV2xIo9e+w0xCtFmaQ5uW/2anfYIAXPTbd0+ilnLPrlo+hdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753871349; c=relaxed/simple; bh=lO7YkAhoMX+qzxXhKtt6Kzmf4wUtQ/sEypG2OHMHblU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=jnB1GG6fT30hIk/zyCPjFoi2P3RcPJgdyKeXHt+rMYsv9GfK5MNzEwPV65a3uw+MYjkHXbqfRtl/6OOf2W75Q9wGtgFeMXzlk/I5OiJxqWdZR4wSYISDyZqsEYI2pAd/cJfliCk2ouy7Kn9DZdcHgdLLSjPTbIhOERtCkT0NioI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=ub84NMA4; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=Qaala2Jg; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=E7ptiLY2; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=gEoL0hF5; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="ub84NMA4"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="Qaala2Jg"; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="E7ptiLY2"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="gEoL0hF5" Received: from imap1.dmz-prg2.suse.org (unknown [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 CF3AD21246; Wed, 30 Jul 2025 10:28:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1753871340; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sbC6Uq5aYunWTU8USVVOdmjcJNM1Dt2n1UGLWwQRu+8=; b=ub84NMA47RseCfjunnnzV3zEfNtor+YWEe+5S145sG5x5HYl5BSql3N9JlMNF8T4rAmeWt j2sVzdr5sajXe/MtlEtloWujysrXpPtVVzNZxLbQ9bb8veUFx6IRvuH+MbUL+xhqd6ygSN +ALiSyCZnYFC3xIp5XzJCbnU7cIEhFM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1753871340; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sbC6Uq5aYunWTU8USVVOdmjcJNM1Dt2n1UGLWwQRu+8=; b=Qaala2Jg8yjaKT5mp/KNtfn3fA/d09lA7WElo6vWN7wurTieSXrVmELQNagpixSgzeiLPE sfg8Ma5WofD1SZDg== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1753871339; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sbC6Uq5aYunWTU8USVVOdmjcJNM1Dt2n1UGLWwQRu+8=; b=E7ptiLY2u8hMlo/1derQYVC1+Ul9LerWDx5sX+rEoaj2rLDGVBC1OcmHBytHryRwffmRyu lqXUpAZYfBHPK7mQKy86uHzBX/MWA1ElAHPJ889PURRUcL/gYa1b+Z9jehl2nzBG7foerw /7tCc1aEnFIrWHOBF2x3/+UJNW/tH3o= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1753871339; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sbC6Uq5aYunWTU8USVVOdmjcJNM1Dt2n1UGLWwQRu+8=; b=gEoL0hF5yZOWd21zLCSzN9WEthatKLWDoAxBh9xa2QrBNDykpAHwEIO3c0TpqKMYk+FAmD 2rPQ29BG5Te9HlAw== 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 B8A871388B; Wed, 30 Jul 2025 10:28:59 +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 KkoMLevziWhvfQAAD6G6ig (envelope-from ); Wed, 30 Jul 2025 10:28:59 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 7277EA094F; Wed, 30 Jul 2025 12:28:59 +0200 (CEST) From: Jan Kara To: Christian Brauner Cc: , "Darrick J . Wong" , Jan Kara , John Garry , "Ritesh Harjani (IBM)" , stable@vger.kernel.org Subject: [PATCH] iomap: Fix broken data integrity guarantees for O_SYNC writes Date: Wed, 30 Jul 2025 12:28:41 +0200 Message-ID: <20250730102840.20470-2-jack@suse.cz> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1920; i=jack@suse.cz; h=from:subject; bh=lO7YkAhoMX+qzxXhKtt6Kzmf4wUtQ/sEypG2OHMHblU=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBoifPYe+pOCTKYAOuLCx+ipNUdUqidRt9KSPJKNZUZ bA5qz16JATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCaInz2AAKCRCcnaoHP2RA2SlQCA ClZnOwpx0K5w2IalXfFQEEJM9eGybMRcz7gyFWpRp2F4W+Ksmm+V1/FrI8TcGHW8ondSO/TG6Lpuh9 ajQCwlfriZcq6gt0IgSE3vatVzfgnP+JhOnFhUhNPJbUu1aqoWsDdrKFK6nhyMP21ZdXhXkZq4uP+u X5O1n5z0SR+iVXdrXNr3wHewSAUTZOBdM14NXVxyry2FxOx642MLvi3pBZA3/F0FbsXW6+DvhBL4gU sllOI9tWNqztsD6ojSKH2/hKStlrc+2CBZRdLmfyPpLOu5DurYAy6gNdnDGarIrVd7G8jAiTUaOzC4 48+LKZvTGm7bS4b3yEExYM+s+mOZLk X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Content-Transfer-Encoding: 8bit X-Spamd-Result: default: False [-1.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[vger.kernel.org,kernel.org,suse.cz,oracle.com,gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TAGGED_RCPT(0.00)[]; RCPT_COUNT_SEVEN(0.00)[7]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; RCVD_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com] X-Spam-Flag: NO X-Spam-Level: X-Spam-Score: -1.30 Commit d279c80e0bac ("iomap: inline iomap_dio_bio_opflags()") has broken the logic in iomap_dio_bio_iter() in a way that when the device does support FUA (or has no writeback cache) and the direct IO happens to freshly allocated or unwritten extents, we will *not* issue fsync after completing direct IO O_SYNC / O_DSYNC write because the IOMAP_DIO_WRITE_THROUGH flag stays mistakenly set. Fix the problem by clearing IOMAP_DIO_WRITE_THROUGH whenever we do not perform FUA write as it was originally intended. CC: John Garry CC: "Ritesh Harjani (IBM)" Fixes: d279c80e0bac ("iomap: inline iomap_dio_bio_opflags()") CC: stable@vger.kernel.org Signed-off-by: Jan Kara --- fs/iomap/direct-io.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) BTW, I've spotted this because some performance tests got suspiciously fast on recent kernels :) Sadly no easy improvement to cherry-pick for me to fix customer issue I'm chasing... diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 6f25d4cfea9f..b84f6af2eb4c 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -363,14 +363,14 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio) if (iomap->flags & IOMAP_F_SHARED) dio->flags |= IOMAP_DIO_COW; - if (iomap->flags & IOMAP_F_NEW) { + if (iomap->flags & IOMAP_F_NEW) need_zeroout = true; - } else if (iomap->type == IOMAP_MAPPED) { - if (iomap_dio_can_use_fua(iomap, dio)) - bio_opf |= REQ_FUA; - else - dio->flags &= ~IOMAP_DIO_WRITE_THROUGH; - } + else if (iomap->type == IOMAP_MAPPED && + iomap_dio_can_use_fua(iomap, dio)) + bio_opf |= REQ_FUA; + + if (!(bio_opf & REQ_FUA)) + dio->flags &= ~IOMAP_DIO_WRITE_THROUGH; /* * We can only do deferred completion for pure overwrites that -- 2.43.0