From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E88FF405C3F; Fri, 4 Sep 2026 06:05:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501932; cv=none; b=ZSO2zWxrUigwAF38gHSamEglSCMGyWmBbstwfeaX2cqgPFPV8RY+uIfm/IPmp7DxLjt7vjPnwaUAFlSpPpzoiuBfdlMOB6Ul6kQm5DWjmCSKHGfaUdHC4ZM8IUApF1Cn4ebhNJnAvjYi+VJucgxnVdgGIC7lxiE+OOuqRIOarMI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501932; c=relaxed/simple; bh=LJY1/2ozq4uMSv6Bn9mtYaq6y1mSa5nQSWDfaoKGSLE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=En2qOBefTo7KCsPOxRH5u5glqwYroN1cukWjHN+OnN2vDyDGxVqLBFLOEdDl9peRLTItn+P/CcOscwwLdDdgn+QsGfhaxXvlGwgsLX49BRKY+2I8SGDvdIkwcQME3A/GKGexW6kpomTCpM6BckBR8J3jS3XLXzVBlixoBTNMv78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Q95FxseX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Q95FxseX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EB631F00A3D; Fri, 4 Sep 2026 06:05:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501930; bh=K/ZrbUxRS6/FQWQo8LyOHi+6UxpWQU3UYWzyN5uBiY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Q95FxseXq7c/El3/3raGTnHC/Izr/q3ab6bCY43+nR11fD+Us+k09bgYbdbPXrPWh bHTvg9qbeTkNVeJuvBLJTsvdfNTcqimd0ZjEW5ov/+qkvo96SZasmaME+YaC0AgVsI 2I9jxss4acqh4Y5AXE1u3VY4zJjq3th+wSzy1xe8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jan Prusakowski , Chao Yu , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.12 003/403] f2fs: fix potential deadloop in prepare_compress_overwrite() Date: Fri, 4 Sep 2026 06:56:46 +0200 Message-ID: <20260904045734.887531784@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chao Yu [ Upstream commit 3147ee567dd9004a49826ddeaf0a4b12865d4409 ] Jan Prusakowski reported a kernel hang issue as below: When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I encountered a problem in generic/475 test where fsstress process gets blocked in __f2fs_write_data_pages() and the test hangs. The options I used are: MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc INFO: task kworker/u8:0:11 blocked for more than 122 seconds. Not tainted 6.14.0-rc3-xfstests-lockdep #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: writeback wb_workfn (flush-253:0) Call Trace: __schedule+0x309/0x8e0 schedule+0x3a/0x100 schedule_preempt_disabled+0x15/0x30 __mutex_lock+0x59a/0xdb0 __f2fs_write_data_pages+0x3ac/0x400 do_writepages+0xe8/0x290 __writeback_single_inode+0x5c/0x360 writeback_sb_inodes+0x22f/0x570 wb_writeback+0xb0/0x410 wb_do_writeback+0x47/0x2f0 wb_workfn+0x5a/0x1c0 process_one_work+0x223/0x5b0 worker_thread+0x1d5/0x3c0 kthread+0xfd/0x230 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 The root cause is: once generic/475 starts toload error table to dm device, f2fs_prepare_compress_overwrite() will loop reading compressed cluster pages due to IO error, meanwhile it has held .writepages lock, it can block all other writeback tasks. Let's fix this issue w/ below changes: - add f2fs_handle_page_eio() in prepare_compress_overwrite() to detect IO error. - detect cp_error earler in f2fs_read_multi_pages(). Fixes: 4c8ff7095bef ("f2fs: support data compression") Reported-by: Jan Prusakowski Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/compress.c | 1 + fs/f2fs/data.c | 10 ++++++---- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index c2ec80c82b6de..9e7fb8d883099 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1141,6 +1141,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc, f2fs_compress_ctx_add_page(cc, page_folio(page)); if (!PageUptodate(page)) { + f2fs_handle_page_eio(sbi, page_folio(page), DATA); release_and_retry: f2fs_put_rpages(cc); f2fs_unlock_rpages(cc, i + 1); diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 16c15360605b0..ec816df4887cc 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2250,6 +2250,12 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, int i; int ret = 0; + if (unlikely(f2fs_cp_error(sbi))) { + ret = -EIO; + from_dnode = false; + goto out_put_dnode; + } + f2fs_bug_on(sbi, f2fs_cluster_is_empty(cc)); last_block_in_file = F2FS_BYTES_TO_BLK(f2fs_readpage_limit(inode) + @@ -2293,10 +2299,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, if (ret) goto out; - if (unlikely(f2fs_cp_error(sbi))) { - ret = -EIO; - goto out_put_dnode; - } f2fs_bug_on(sbi, dn.data_blkaddr != COMPRESS_ADDR); skip_reading_dnode: -- 2.53.0