From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41552 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755128AbeCWKIH (ORCPT ); Fri, 23 Mar 2018 06:08:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Filipe Manana , Sasha Levin Subject: [PATCH 4.9 076/177] Btrfs: fix incorrect space accounting after failure to insert inline extent Date: Fri, 23 Mar 2018 10:53:24 +0100 Message-Id: <20180323094208.668814409@linuxfoundation.org> In-Reply-To: <20180323094205.090519271@linuxfoundation.org> References: <20180323094205.090519271@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Filipe Manana [ Upstream commit 1c81ba237bcecad9bc885a1ddcf02d725ea38482 ] When using compression, if we fail to insert an inline extent we incorrectly end up attempting to free the reserved data space twice, once through extent_clear_unlock_delalloc(), because we pass it the flag EXTENT_DO_ACCOUNTING, and once through a direct call to btrfs_free_reserved_data_space_noquota(). This results in a trace like the following: [ 834.576240] ------------[ cut here ]------------ [ 834.576825] WARNING: CPU: 2 PID: 486 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs] [ 834.579501] Modules linked in: btrfs crc32c_generic xor raid6_pq ppdev i2c_piix4 acpi_cpufreq psmouse tpm_tis parport_pc pcspkr serio_raw tpm_tis_core sg parport evdev i2c_core tpm button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs] [ 834.592116] CPU: 2 PID: 486 Comm: kworker/u32:4 Not tainted 4.10.0-rc8-btrfs-next-37+ #2 [ 834.593316] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 834.595273] Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs] [ 834.596103] Call Trace: [ 834.596103] dump_stack+0x67/0x90 [ 834.596103] __warn+0xc2/0xdd [ 834.596103] warn_slowpath_null+0x1d/0x1f [ 834.596103] btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs] [ 834.596103] compress_file_range.constprop.42+0x2fa/0x3fc [btrfs] [ 834.596103] ? submit_compressed_extents+0x3a7/0x3a7 [btrfs] [ 834.596103] async_cow_start+0x32/0x4d [btrfs] [ 834.596103] btrfs_scrubparity_helper+0x187/0x3e7 [btrfs] [ 834.596103] btrfs_delalloc_helper+0xe/0x10 [btrfs] [ 834.596103] process_one_work+0x273/0x4e4 [ 834.596103] worker_thread+0x1eb/0x2ca [ 834.596103] ? rescuer_thread+0x2b6/0x2b6 [ 834.596103] kthread+0x100/0x108 [ 834.596103] ? __list_del_entry+0x22/0x22 [ 834.596103] ret_from_fork+0x2e/0x40 [ 834.611656] ---[ end trace 719902fe6bdef08f ]--- So fix this by not calling directly btrfs_free_reserved_data_space_noquota() if an error happened. Signed-off-by: Filipe Manana Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/inode.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -567,8 +567,10 @@ cont: PAGE_SET_WRITEBACK | page_error_op | PAGE_END_WRITEBACK); - btrfs_free_reserved_data_space_noquota(inode, start, - end - start + 1); + if (ret == 0) + btrfs_free_reserved_data_space_noquota(inode, + start, + end - start + 1); goto free_pages_out; } }