Goffredo Baroncelli, Thu, 10 Feb 2011 19:24:57 +0100: > On 02/09/2011 09:12 PM, Lubos Kolouch wrote: >> Goffredo Baroncelli, Wed, 09 Feb 2011 19:25:34 +0100: >> >>> On 02/08/2011 10:26 PM, Lubos Kolouch wrote: >>>> Goffredo Baroncelli, Tue, 08 Feb 2011 21:00:25 +0100: >>>> >>>>> On 02/08/2011 07:57 AM, Lubos Kolouch wrote: >>>>>> Hi, >>>>>> >>>>>> I'm hitting this issue - sda5 is a normal device, nothing to do >>>>>> with loop, encryption etc. >>>>>> >>>>>> # mkfs.btrfs /dev/sda5 >>>>>> >>>>>> WARNING! - Btrfs v0.19-35-g1b444cd-dirty IS EXPERIMENTAL WARNING! - >>>>>> see http://btrfs.wiki.kernel.org before using >>>>>> >>>>>> error checking /dev/sda5 mount status >>>>>> >>>>>> Is there something I can do to resolve this? >>>>> >>>>> Some months ago I posted a patch [*] which allows to create a >>>>> filesystem even if an integrity tests fail. Anyway it would be >>>>> interesting understand why mkfs.btrfs fails. It is possible to have >>>>> a strace of the command ? >>>>> >>>>> >>>> here ... http://paste.pocoo.org/show/334638/ but it is not in chroot, >>>> it is in "normal" system >>>> >>>> Lubos >>>> >>>> >>> Hi Lubos, >>> >>> Could you post also the output of "cat /proc/mounts" command and the >>> output of "btrfs filesystem show" command. I cannot understand what >>> should be the problem. >> >> Hi Goffredo, >> >> Sure, >> # cat /proc/mounts >> >> rootfs / rootfs rw 0 0 >> /dev/root / btrfs rw,noatime,compress,ssd 0 0 proc /proc proc >> rw,nosuid,nodev,noexec,relatime 0 0 rc-svcdir /lib/rc/init.d tmpfs >> rw,nosuid,nodev,noexec,relatime,size=1024k,mode=755 0 0 sysfs /sys >> sysfs rw,nosuid,nodev,noexec,relatime 0 0 securityfs >> /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0 >> debugfs /sys/kernel/debug debugfs rw,nosuid,nodev,noexec,relatime 0 0 >> udev /dev devtmpfs >> rw,nosuid,relatime,size=10240k,nr_inodes=217934,mode=755 0 0 fusectl >> /sys/fs/fuse/connections fusectl rw,relatime 0 0 none /dev/pts devpts >> rw,relatime,mode=600,ptmxmode=000 0 0 none /dev/shm tmpfs rw,relatime 0 >> 0 >> /dev/sda1 /boot ext2 rw,relatime,errors=continue 0 0 none >> /var/tmp/portage tmpfs rw,relatime 0 0 binfmt_misc >> /proc/sys/fs/binfmt_misc binfmt_misc rw,nosuid,nodev,noexec,relatime 0 >> 0 >> /dev/mapper/_dev_sda6 /home btrfs rw,noatime,compress,ssd 0 0 >> >> # btrfs filesystem show >> >> Label: none uuid: fd070c17-e98b-4b50-9fa8-3453482aafa2 >> Total devices 1 FS bytes used 5.51GB >> devid 1 size 18.64GB used 10.79GB path /dev/sda2 >> >> Label: none uuid: bf9a1b00-f8bd-44d3-b140-10eea088a60e >> Total devices 1 FS bytes used 6.73GB >> devid 1 size 19.54GB used 19.54GB path /dev/sda5 >> >> Label: none uuid: ae0ba016-1945-4e7a-9fb4-e9311d199727 >> Total devices 1 FS bytes used 57.50GB devid 1 size 78.91GB used >> 78.91GB path /dev/dm-0 >> >> # mkfs.btrfs /dev/sda5 >> >> WARNING! - Btrfs v0.19-35-g1b444cd-dirty IS EXPERIMENTAL WARNING! - see >> http://btrfs.wiki.kernel.org before using >> >> error checking /dev/sda5 mount status >> >> Also, I can mount it no problem - strange, isn't it > > > Ok, I think to have track down the problem. To me it seems a bug in > mkfs.btrfs. > > The first thing that should be highlighted is that you are trying to > format an already btrfs formatted device. In this there is not anything > wrong. > > However, before formatting a device mkfs.btrfs performs some sanity > check. It checks if the device is already mounted, scanning > /proc/mounts. > > In a normal case (the device which will be formatted doesn't contain a > btrfs filesystem), mkfs.btrfs is smart enough to don't check device > which are in /proc/mounts bat doesn't exist (like /dev/root). > > Instead when the device which will be formatted already contains a btrfs > filesystem, mkfs.btrfs performs a different checks. In fact it considers > also the case of a multi-device based btrfs filesystem. However in this > case it doesn't skip a not existent device but it raises an error. I > think that this is a bug. > > As workaround I suggest the following: make a link between the real root > device and /dev/root. > > It should be sufficient to format the device. >
Hello - you are right... # ln -s /dev/sda2 /dev/root # mkfs.btrfs /dev/sda5 WARNING! - Btrfs v0.19-35-g1b444cd-dirty IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using fs created label (null) on /dev/sda5 nodesize 4096 leafsize 4096 sectorsize 4096 size 19.54GB Btrfs v0.19-35-g1b444cd-dirty Lubos -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
