From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: Dirtiable inode bdi default != sb bdi btrfs Date: Tue, 28 Sep 2010 10:05:49 +0300 Message-ID: <1285657549.2437.28.camel@localhost> References: <4C9AA546.6050201@cesarb.net> <20100923123849.8975fe47.akpm@linux-foundation.org> <20100927222548.GG3610@quack.suse.cz> <20100927225452.GG4270@think> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jan Kara , Cesar Eduardo Barros , Andrew Morton , hch@lst.de, linux-kernel@vger.kernel.org, Jens Axboe , linux-btrfs@vger.kernel.org, Alexander Viro , linux-fsdevel@vger.kernel.org, stable@kernel.org, Jens Axboe , =?UTF-8?Q?Micha=C5=82?= Piotrowski , Chuck Ebbert , kernel@lists.fedoraproject.org To: Chris Mason Return-path: In-Reply-To: <20100927225452.GG4270@think> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, 2010-09-27 at 18:54 -0400, Chris Mason wrote: > On Tue, Sep 28, 2010 at 12:25:48AM +0200, Jan Kara wrote: > > [Added CCs for similar ecryptfs warning] > > On Thu 23-09-10 12:38:49, Andrew Morton wrote: > > > > This started appearing for me on v2.6.36-rc5-49-gc79bd89; it di= d not=20 > > > > happen on v2.6.36-rc5-33-g1ce1e41, probably because it does not= have=20 > > > > commit 692ebd17c2905313fff3c504c249c6a0faad16ec which introduce= s the=20 > > > > warning. > > > > [...] > > > > device fsid 44d595920ddedfa-3ece6b56e80f689e devid 1 transid 22= 342=20 > > > > /dev/mapper/vg_cesarbinspiro-lv_home > > > > SELinux: initialized (dev dm-3, type btrfs), uses xattr > > > > ------------[ cut here ]------------ > > > > WARNING: at fs/fs-writeback.c:87 inode_to_bdi+0x62/0x6d() > > > > Hardware name: Inspiron N4010 > > > > Dirtiable inode bdi default !=3D sb bdi btrfs > > > > Modules linked in: ipv6 kvm_intel kvm uinput arc4 ecb=20 > > > > snd_hda_codec_intelhdmi snd_hda_codec_realtek iwlagn snd_hda_in= tel=20 > > > > iwlcore snd_hda_codec uvcvideo snd_hwdep mac80211 videodev snd_= seq=20 > > > > snd_seq_device v4l1_compat snd_pcm atl1c v4l2_compat_ioctl32 bt= usb=20 > > > > cfg80211 snd_timer i2c_i801 bluetooth iTCO_wdt dell_wmi dell_la= ptop snd=20 > > > > pcspkr wmi dcdbas shpchp iTCO_vendor_support soundcore snd_page= _alloc=20 > > > > rfkill joydev microcode btrfs zlib_deflate libcrc32c cryptd aes= _x86_64=20 > > > > aes_generic xts gf128mul dm_crypt usb_storage i915 drm_kms_help= er drm=20 > > > > i2c_algo_bit i2c_core video output [last unloaded: scsi_wait_sc= an] > > > > Pid: 1073, comm: find Not tainted 2.6.36-rc5+ #8 > > > > Call Trace: > > > > [] warn_slowpath_common+0x85/0x9d > > > > [] warn_slowpath_fmt+0x46/0x48 > > > > [] inode_to_bdi+0x62/0x6d > > > > [] __mark_inode_dirty+0xd0/0x177 > > > > [] touch_atime+0x107/0x12a > > > > [] ? filldir+0x0/0xd0 > > > > [] vfs_readdir+0x8d/0xb4 > > > > [] sys_getdents+0x81/0xd1 > > > > [] system_call_fastpath+0x16/0x1b > > Thanks for the report. These bdi pointers are a mess. As Chris po= inted > > out, btrfs forgets to properly initialize inode->i_mapping.backing_= dev_info > > for directories and special inodes and thus these were previously a= ttached > > to default_backing_dev_info which probably isn't what Chris would l= ike to > > see. >=20 > There's no actual writeback for these, so it works fine for btrfs eit= her > way. Side note: every time inode is marked as dirty, we wake up a bdi thread or the default bdi thread. So if we have inodes which do not need write-back, we should never mark them as dirty. --=20 Best Regards, Artem Bityutskiy (=D0=90=D1=80=D1=82=D1=91=D0=BC =D0=91=D0=B8=D1=82=D1=8E= =D1=86=D0=BA=D0=B8=D0=B9)