From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goffredo Baroncelli Subject: Re: Still Problems with /dev/btrfs-control Date: Sat, 9 Jan 2010 12:05:34 +0100 Message-ID: <201001091205.34578.kreijack@libero.it> References: <20100109114203.70ae0c14@simplux> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Cc: linux-btrfs@vger.kernel.org, Kay Sievers To: "Dipl.-Ing. Michael Niederle" Return-path: In-Reply-To: <20100109114203.70ae0c14@simplux> List-ID: Hi Michael On Saturday 09 January 2010, Dipl.-Ing. Michael Niederle wrote: > Thanks for the quick reply! > > But I still have problems with btrfsctl: > > stat /dev/btrfs-control > File: `/dev/btrfs-control' > Size: 0 Blocks: 0 IO Block: 4096 block special file > Device: ch/12d Inode: 659848 Links: 1 Device type: a,3e Ok, two things: 1) btrfs-control is a *character* device and _not_ a *block device* 2) on my system it is allocated under 10,55 (major/minor). $ stat /dev/btrfs-control File: `/dev/btrfs-control' Size: 0 Blocks: 0 IO Block: 4096 character special file Device: fh/15d Inode: 2404 Links: 1 Device type: a,37 Access: (0660/crw-rw----) Uid: (0/ root) Gid: ( 0/ root) Access: 2010-01-09 11:35:30.764909719 +0100 Modify: 2010-01-09 11:35:30.764909719 +0100 Change: 2010-01-09 11:35:30.764909719 +0100 ghigo@venice:~$ ls -l /dev/btrfs-control crw-rw---- 1 root root 10, 55 2010-01-09 11:35 /dev/btrfs-control Looking at the source btrfs-unstable/fs/btrfs$ grep -A 2 -B 2 "btrfs-control" *.c super.c-static struct miscdevice btrfs_misc = { super.c- .minor = MISC_DYNAMIC_MINOR, super.c: .name = "btrfs-control", super.c- .fops = &btrfs_ctl_fops super.c-}; It seems that it is dynamically allocated. The "major" should be always 10, the minor may be find with $ cat /proc/misc | grep btrfs-control 55 btrfs-control Or by $ cat /sys/class/misc/btrfs-control/dev 10:55 Regards Goffredo > Access: (0644/brw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) > Access: 2010-01-09 11:31:15.757979602 +0100 > Modify: 2010-01-09 11:31:15.757979602 +0100 > Change: 2010-01-09 11:31:15.757979602 +0100 > > mount -l -t btrfs > /dev/sda3 on / type btrfs (rw,relatime,noacl) [Alpha4] > > btrfsctl -A /dev/sda3 > failed to open /dev/btrfs-control: No such device or address > > Remark: When the btrfs-filesystem is originally mounted (from the startup- code > in the initial ramdisk), /dev/btrfs-control is not yet existant, because the > dev-directory is contained in the btrfs-filesystem. > > Everything else works fine. > > Greetings, Michael > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512