On Wed, 2010-09-29 at 15:00 +0200, Jan Kara wrote: > On Tue 28-09-10 10:05:49, Artem Bityutskiy wrote: > > 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 did not > > > > > > happen on v2.6.36-rc5-33-g1ce1e41, probably because it does not have > > > > > > commit 692ebd17c2905313fff3c504c249c6a0faad16ec which introduces the > > > > > > warning. > > > > > > [...] > > > > > > device fsid 44d595920ddedfa-3ece6b56e80f689e devid 1 transid 22342 > > > > > > /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 != sb bdi btrfs > > > > > > Modules linked in: ipv6 kvm_intel kvm uinput arc4 ecb > > > > > > snd_hda_codec_intelhdmi snd_hda_codec_realtek iwlagn snd_hda_intel > > > > > > iwlcore snd_hda_codec uvcvideo snd_hwdep mac80211 videodev snd_seq > > > > > > snd_seq_device v4l1_compat snd_pcm atl1c v4l2_compat_ioctl32 btusb > > > > > > cfg80211 snd_timer i2c_i801 bluetooth iTCO_wdt dell_wmi dell_laptop snd > > > > > > pcspkr wmi dcdbas shpchp iTCO_vendor_support soundcore snd_page_alloc > > > > > > rfkill joydev microcode btrfs zlib_deflate libcrc32c cryptd aes_x86_64 > > > > > > aes_generic xts gf128mul dm_crypt usb_storage i915 drm_kms_helper drm > > > > > > i2c_algo_bit i2c_core video output [last unloaded: scsi_wait_scan] > > > > > > Pid: 1073, comm: find Not tainted 2.6.36-rc5+ #8 > > > > > > Call Trace: > > > > > > [<ffffffff8104d0e4>] warn_slowpath_common+0x85/0x9d > > > > > > [<ffffffff8104d19f>] warn_slowpath_fmt+0x46/0x48 > > > > > > [<ffffffff811308b7>] inode_to_bdi+0x62/0x6d > > > > > > [<ffffffff81131b48>] __mark_inode_dirty+0xd0/0x177 > > > > > > [<ffffffff81127168>] touch_atime+0x107/0x12a > > > > > > [<ffffffff81122384>] ? filldir+0x0/0xd0 > > > > > > [<ffffffff8112259b>] vfs_readdir+0x8d/0xb4 > > > > > > [<ffffffff8112270b>] sys_getdents+0x81/0xd1 > > > > > > [<ffffffff81009c72>] system_call_fastpath+0x16/0x1b > > > > Thanks for the report. These bdi pointers are a mess. As Chris pointed > > > > out, btrfs forgets to properly initialize inode->i_mapping.backing_dev_info > > > > for directories and special inodes and thus these were previously attached > > > > to default_backing_dev_info which probably isn't what Chris would like to > > > > see. > > > > > > There's no actual writeback for these, so it works fine for btrfs either > > > 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. > Are you sure? I think we wake up the thread only when it's the first > dirty inode for the bdi... Err, right. If no one ever marks it as clean then we won't wake-up the thread. But I thought that marking it as dirty even once is bad because this causes bdi thread creation, which consumes resources. Sorry for my ignorance, I did not really follow the conversation, I just remember that when I looked at bdi stuff, I noticed that during boot the kernel created many bdi threads which were never used then. They eventually exited. But I thought that creating useless bdi threads it about concuming resources and slowing down the boot. As I remember, the reason was touch_atime() for some of the threads. But really, I did not dig this, I just noticed this conversation and wanted to let you know about the issue I noticed this summer. -- Best Regards, Artem Bityutskiy (ÐÑÑÑÐ ÐÐÑÑÑÐÐÐ) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
