Hi, If I attempt to mount a non-existant subvolume, e.g., mount -o subvol=1 /dev/sda6 /mnt then I get an an oops (see end of message). /dev/sda6 is my root filesystem, ''btrfs sub list /'' gives ID 331 top level 5 path snap/rawhide ID 341 top level 5 path snap/20101014 ID 342 top level 5 path snap/20101016 ID 343 top level 5 path snap/20101020 subvol 343 is set as the default subvolume. Cheers, Ralph. PS. What I''m actually trying to achieve is get back to the original subvolume I had before I did a ''btrfs subvol set-default'', is there any way of doing that? [ 463.981331] device label btr_root devid 1 transid 208372 /dev/sda6 [ 475.254561] BUG: unable to handle kernel NULL pointer dereference at 00000000000002d0 [ 475.254574] IP: [<ffffffff8113ab35>] bio_get_nr_vecs+0x10/0x3a [ 475.254591] PGD 205cff067 PUD 205d02067 PMD 0 [ 475.254602] Oops: 0000 [#1] SMP [ 475.254609] last sysfs file: /sys/devices/pci0000:00/0000:00:11.0/host3/target3:0:0/3:0:0:0/block/sda/sda5/stat [ 475.254618] CPU 3 [ 475.254621] Modules linked in: k8temp it87 hwmon_vid ipv6 cpufreq_ondemand powernow_k8 freq_table mperf kvm_amd kvm uinput arc4 ecb snd_hda_codec_atihdmi rt73usb r8169 ipheth snd_hda_codec_realtek crc_itu_t snd_usb_audio snd_hda_intel snd_hda_codec serio_raw rt2x00usb wmi rt2x00lib shpchp e100 snd_seq snd_pcm uvcvideo videodev snd_hwdep v4l1_compat v4l2_compat_ioctl32 snd_timer mii mac80211 snd_usbmidi_lib snd_rawmidi snd_seq_device snd microcode soundcore edac_core edac_mce_amd cfg80211 k10temp i2c_piix4 snd_page_alloc rfkill btrfs zlib_deflate libcrc32c pata_acpi ata_generic pata_atiixp radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core [last unloaded: scsi_wait_scan] [ 475.254724] [ 475.254733] Pid: 418, comm: btrfs-transacti Not tainted 2.6.35.6-43.fc14.x86_64 #1 GA-MA790GP-DS4H/GA-MA790GP-DS4H [ 475.254741] RIP: 0010:[<ffffffff8113ab35>] [<ffffffff8113ab35>] bio_get_nr_vecs+0x10/0x3a [ 475.254754] RSP: 0018:ffff88021b54fa60 EFLAGS: 00010246 [ 475.254760] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000100 [ 475.254766] RDX: ffffea00071cd9a8 RSI: ffff88021bac4030 RDI: ffff8802278296c0 [ 475.254773] RBP: ffff88021b54fa60 R08: 0000000000001000 R09: 0000000000000000 [ 475.254779] R10: ffff8802278296c0 R11: ffff88021b54fcbc R12: 0000000000001000 [ 475.254786] R13: ffff88021b54fc30 R14: 0000000000000000 R15: 000000000705ad10 [ 475.254794] FS: 00007f6c0c59f980(0000) GS:ffff880002180000(0000) knlGS:00000000f4c7eb70 [ 475.254801] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 475.254807] CR2: 00000000000002d0 CR3: 0000000205ca7000 CR4: 00000000000006e0 [ 475.254813] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 475.254820] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 475.254827] Process btrfs-transacti (pid: 418, threadinfo ffff88021b54e000, task ffff88021b1e1740) [ 475.254833] Stack: [ 475.254836] ffff88021b54fad0 ffffffffa01482d0 ffffea00071cd9a8 ffff88021bac42a0 [ 475.254846] <0> ffff88021bac4030 00000441810da44c 0000000000000000 ffffea00071cd9a8 [ 475.254856] <0> ffff88021b54fad0 ffffea00071cd9a8 0000000e0b5a2000 ffff88021bac4030 [ 475.254868] Call Trace: [ 475.254920] [<ffffffffa01482d0>] submit_extent_page.clone.16+0xfc/0x1bd [btrfs] [ 475.254966] [<ffffffffa014acc2>] __extent_writepage+0x507/0x55f [btrfs] [ 475.255009] [<ffffffffa0148f9c>] ? end_bio_extent_writepage+0x0/0x15f [btrfs] [ 475.255052] [<ffffffffa014b092>] extent_write_full_page+0x88/0xb7 [btrfs] [ 475.255087] [<ffffffffa012a89d>] ? btree_get_extent+0x0/0x181 [btrfs] [ 475.255097] [<ffffffff810e6c2e>] ? dec_zone_page_state+0x0/0x36 [ 475.255132] [<ffffffffa012c57b>] btree_writepage+0x4f/0xef [btrfs] [ 475.255141] [<ffffffff810da628>] write_one_page+0x77/0xbb [ 475.255181] [<ffffffffa01563f1>] ? btrfs_wake_function+0x0/0x15 [btrfs] [ 475.255219] [<ffffffffa012f814>] btrfs_write_marked_extents+0xe2/0x11e [btrfs] [ 475.255256] [<ffffffffa012f982>] btrfs_write_and_wait_marked_extents+0x1e/0x41 [btrfs] [ 475.255292] [<ffffffffa012f9ec>] btrfs_write_and_wait_transaction+0x47/0x49 [btrfs] [ 475.255329] [<ffffffffa012ffad>] btrfs_commit_transaction+0x4ef/0x5e6 [btrfs] [ 475.255339] [<ffffffff810663c3>] ? autoremove_wake_function+0x0/0x39 [ 475.255373] [<ffffffffa012b268>] transaction_kthread+0x170/0x225 [btrfs] [ 475.255380] [<ffffffffa012b0f8>] ? transaction_kthread+0x0/0x225 [btrfs] [ 475.255380] [<ffffffff81065f29>] kthread+0x7f/0x87 [ 475.255380] [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10 [ 475.255380] [<ffffffff81065eaa>] ? kthread+0x0/0x87 [ 475.255380] [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10 [ 475.255380] Code: c9 c3 55 48 89 e5 0f 1f 44 00 00 f0 ff 0f 0f 94 c0 84 c0 c9 0f 95 c0 0f b6 c0 c3 55 48 89 e5 0f 1f 44 00 00 48 8b 87 98 00 00 00 <48> 8b 88 d0 02 00 00 8b 81 8c 04 00 00 0f b7 91 b2 04 00 00 c9 [ 475.255380] RIP [<ffffffff8113ab35>] bio_get_nr_vecs+0x10/0x3a [ 475.255380] RSP <ffff88021b54fa60> [ 475.255380] CR2: 00000000000002d0 [ 475.255564] ---[ end trace 9116819b3f146cc9 ]--- -- 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
On Sat, Oct 23, 2010 at 10:42:56AM +1300, Ralph Loader wrote:> Hi, > > If I attempt to mount a non-existant subvolume, e.g., > > mount -o subvol=1 /dev/sda6 /mnt > > then I get an an oops (see end of message). > > /dev/sda6 is my root filesystem, ''btrfs sub list /'' gives > > ID 331 top level 5 path snap/rawhide > ID 341 top level 5 path snap/20101014 > ID 342 top level 5 path snap/20101016 > ID 343 top level 5 path snap/20101020 > > subvol 343 is set as the default subvolume. >You''ll want this http://git.kernel.org/?p=linux/kernel/git/josef/btrfs-work.git;a=commit;h=a5ecef26de54d54982053e3f6895df6e39807b07> Cheers, > Ralph. > > PS. What I''m actually trying to achieve is get back to the original subvolume I had before I did a ''btrfs subvol set-default'', is there any way of doing that? >mount -o subvolid=0. Thanks, Josef -- 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