From mboxrd@z Thu Jan 1 00:00:00 1970 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 454EF20EDC8; Wed, 25 Sep 2024 12:09:14 +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=1727266154; cv=none; b=cmtSgyKNi8xm3D8gtZFyWYIk+AUzasKhrqo1iXZefDj54eKXj/vda2btm8c4jKZr3PS7/gZaKBO0/h38umjUh9oZBNE45pR0chgkAVCFUVhaXN6zMDgaUBgYqB9yjqBlySXexXr1+hxkZ4qISrPWrRuJWWQ2C54FuR4C0jXCtGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727266154; c=relaxed/simple; bh=DLRwwhJALq3terZc9vA18D/Jwar7g4IeRYQBGkk+6nw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q0S6cUifDyAp9Xh4FDyT7NXMSUTg7wOYeVyhdLjOvNTQftZl0T4DlNQd0YLgNwjao79y9Ml2AtvmuALpBX7Jvl0y9fneemyv9HWsmNynqOrVTZ3KejIe6O3X73VNTwlpgiVHgSyntvyHReEUP98gVnjAOL7VvzGGLISSpNXQoKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SGaB6LLH; 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="SGaB6LLH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 194C3C4CEC3; Wed, 25 Sep 2024 12:09:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727266154; bh=DLRwwhJALq3terZc9vA18D/Jwar7g4IeRYQBGkk+6nw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SGaB6LLH34joF/KfpkTUQxJVGDVtb3mmAb0szlobqPH/kFL9gARHK1haG0JBYawtM Bu6f6nWDx3ine/2L4dMbR44iHCyAdngGL88XMv6jmt9w3NC4f69GgGwHqsB5qdVoEG kqfQyN3X1H4z10MIyml1qVIaLX8MNO+mISkw9pp3q0glnD/5tMYCWsZV3ogIJM6spk 57NqP2YEY3z5+r09ezVw+HBN+7AgseBByNxVWImQbiSyw5gTNUQs6qNSqlKT173qhU RZobSuRJiUAW8XrAMYcbaIoteEBUJBeYL4702vjEQMouELiToP+GZ6jrzvEQL4hzFq CmUAWCn1Gb+dw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christoph Hellwig , "Darrick J . Wong" , Christian Brauner , Sasha Levin , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 6.10 195/197] iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release Date: Wed, 25 Sep 2024 07:53:34 -0400 Message-ID: <20240925115823.1303019-195-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240925115823.1303019-1-sashal@kernel.org> References: <20240925115823.1303019-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.10.11 Content-Transfer-Encoding: 8bit From: Christoph Hellwig [ Upstream commit 7a9d43eace888a0ee6095035997bb138425844d3 ] When direct I/O completions invalidates the page cache it holds neither the i_rwsem nor the invalidate_lock so it can be racing with iomap_write_delalloc_release. If the search for the end of the region that contains data returns the start offset we hit such a race and just need to look for the end of the newly created hole instead. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240910043949.3481298-2-hch@lst.de Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index d505636035af3..74ee76f772d86 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1226,7 +1226,15 @@ static int iomap_write_delalloc_release(struct inode *inode, error = data_end; goto out_unlock; } - WARN_ON_ONCE(data_end <= start_byte); + + /* + * If we race with post-direct I/O invalidation of the page cache, + * there might be no data left at start_byte. + */ + if (data_end == start_byte) + continue; + + WARN_ON_ONCE(data_end < start_byte); WARN_ON_ONCE(data_end > scan_end_byte); error = iomap_write_delalloc_scan(inode, &punch_start_byte, -- 2.43.0