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 B8E1FEED8 for ; Wed, 18 Mar 2026 00:46:05 +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=1773794765; cv=none; b=tENaGDyPSEqd8ggiAbT5MiTMEImXDlTCeMUEHq+gZ56FpjRhb1VTEYpDnkD/hZumkji5B+viIAVxiWK9nCY2la5/FBMWQtqzh5iBIjBQ/umFeS3ul0bcwH534Qz3rtjCYUmzuhLWLg0NMSuIN4wyxBVyqR2tWdDmIhpIfor/9JM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773794765; c=relaxed/simple; bh=lWeiDp/P+HqzVyjeFLZYWHE/wlYd0FATDZf4G7+yQUM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bSBuUEwccIOgrXVS6DLSNp/X3FM9QCfGnmoivxY8Xsku+Ge01aFGdYccDu5eG+K3abfo98RkIg6e1cSHAfAS4gvTqN56xsp5X+g7sO5xFEgEsuTJF2zUySYiDPBP36kFBTxSZrWNSwxhk6arDT5sKgxKKlKH7lmhmbOzqEGhHzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NamDh/vv; 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="NamDh/vv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E5DDC4CEF7; Wed, 18 Mar 2026 00:46:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773794765; bh=lWeiDp/P+HqzVyjeFLZYWHE/wlYd0FATDZf4G7+yQUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NamDh/vvP2zrMZTLKtk/lf5/5oqKFOjA2fN705VWQFOyJjjb6YaWc2V9MtdkI2nLb UnHC1w5SemWcIJ3b+c2Kel3VhaDVAcUVLjkI1DQ78i0rviAW3T6lYdxL7I/L+HmumF kFQKYxDffRLkezbwdyebZrvoJ7EDoWmY7WlXPnYF0a2Mn/5heZixd5i1up//JJtIir gJq/bfqxKyvll8/dMO/sYdvq9CxFDrrnDn2S5Q6EUM47aKXxaQLREbjRu45C3aIibm elFa5cDHMSZFmx7LVaETD4TXIzJuiVhAPNkNM6xvi0CeW12h9jpWi7LIYQNYWJtpEk lPKe841ANp/Dw== From: Sasha Levin To: stable@vger.kernel.org Cc: "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , Christian Brauner , Sasha Levin Subject: [PATCH 6.6.y] iomap: reject delalloc mappings during writeback Date: Tue, 17 Mar 2026 20:46:03 -0400 Message-ID: <20260318004603.406498-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2026031712-muskiness-fraction-b148@gregkh> References: <2026031712-muskiness-fraction-b148@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Darrick J. Wong" [ Upstream commit d320f160aa5ff36cdf83c645cca52b615e866e32 ] Filesystems should never provide a delayed allocation mapping to writeback; they're supposed to allocate the space before replying. This can lead to weird IO errors and crashes in the block layer if the filesystem is being malicious, or if it hadn't set iomap->dev because it's a delalloc mapping. Fix this by failing writeback on delalloc mappings. Currently no filesystems actually misbehave in this manner, but we ought to be stricter about things like that. Cc: stable@vger.kernel.org # v5.5 Fixes: 598ecfbaa742ac ("iomap: lift the xfs writeback code to iomap") Signed-off-by: Darrick J. Wong Link: https://patch.msgid.link/20260302173002.GL13829@frogsfrogsfrogs Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Christian Brauner [ no ioend.c ] Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 7e9480150d61e..c5d439f8e2254 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1838,10 +1838,19 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, if (error) break; trace_iomap_writepage_map(inode, &wpc->iomap); - if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) - continue; - if (wpc->iomap.type == IOMAP_HOLE) + switch (wpc->iomap.type) { + case IOMAP_UNWRITTEN: + case IOMAP_MAPPED: + break; + case IOMAP_HOLE: continue; + default: + WARN_ON_ONCE(1); + error = -EIO; + break; + } + if (error) + break; iomap_add_to_ioend(inode, pos, folio, ifs, wpc, wbc, &submit_list); count++; -- 2.51.0