Last night, this event jammed up a good chunk of my server:
Mar 4 01:51:36 vlad kernel: btrfs searching for 1716224 bytes, num_bytes 1716224, loop 2, allowed_alloc 1
Mar 4 01:51:36 vlad kernel: btrfs searching for 860160 bytes, num_bytes 860160, loop 2, allowed_alloc 1
[lots of this...]
Mar 4 01:55:52 vlad kernel: btrfs searching for 4096 bytes, num_bytes 4096, loop 2, allowed_alloc 1
Mar 4 01:55:52 vlad kernel: btrfs allocation failed flags 1, wanted 4096
Mar 4 01:55:52 vlad kernel: space_info has 0 free, is full
Mar 4 01:55:52 vlad kernel: block group 12582912 has 8388608 bytes, 8388608 used 0 pinned 0 reserved
Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
Mar 4 01:55:52 vlad kernel: block group 1103101952 has 1073741824 bytes, 1073741824 used 0 pinned 0 reserved
Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
[30 more lines of this]
Mar 4 01:55:52 vlad kernel: ------------[ cut here ]------------
Mar 4 01:55:52 vlad kernel: kernel BUG at fs/btrfs/extent-tree.c:3190!
Mar 4 01:55:52 vlad kernel: invalid opcode: 0000 [#1]
Mar 4 01:55:52 vlad kernel: last sysfs file: /sys/devices/virtual/block/dm-1/removable
Mar 4 01:55:52 vlad kernel: CPU 0
Mar 4 01:55:52 vlad kernel: Modules linked in: tcp_diag inet_diag kqemu tun cpufreq_userspace ipv6 nfsd nfs lockd nfs_acl auth_rpcgss sunrpc bridge stp llc btrfs zlib_deflate xfs exportfs it87 hwmon_vid powernow_k8 sbp2 ieee1394 ide_generic ide_gd_mod ide_cd_mod pcspkr evdev k8temp hwmon i2c_viapro i2c_core button usbhid usb_storage libusual dm_mirror dm_region_hash dm_log dm_snapshot dm_mod raid1 md_mod sg sr_mod cdrom via82cxxx floppy via_rhine mii ehci_hcd uhci_hcd usbcore pata_via ide_pci_generic ide_core sd_mod thermal processor fan unix
Mar 4 01:55:52 vlad kernel: Pid: 218, comm: pdflush Tainted: G B 2.6.29-rc6 #1 System Product Name
Mar 4 01:55:52 vlad kernel: RIP: 0010:[<ffffffffa0256b6b>] [<ffffffffa0256b6b>] __btrfs_reserve_extent+0x296/0x2ab [btrfs]
Mar 4 01:55:52 vlad kernel: RSP: 0018:ffff88003ea618d0 EFLAGS: 00010282
Mar 4 01:55:52 vlad kernel: RAX: ffff880039924aa0 RBX: ffff8800399249d0 RCX: 0000000000001000
Mar 4 01:55:52 vlad kernel: RDX: 00000000ffffffff RSI: 0000000000023b8a RDI: ffff880039924a98
Mar 4 01:55:52 vlad kernel: RBP: ffff880039924a88 R08: 0000000000000000 R09: 000000000000000a
Mar 4 01:55:52 vlad kernel: R10: 000000000000000a R11: ffff88000100f980 R12: ffff880039924a98
Mar 4 01:55:52 vlad kernel: R13: 0000000000001000 R14: ffff88003cb74488 R15: 0000000000001000
Mar 4 01:55:52 vlad kernel: FS: 00007ff4154246e0(0000) GS:ffffffff80577010(0000) knlGS:0000000000000000
Mar 4 01:55:52 vlad kernel: CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
Mar 4 01:55:52 vlad kernel: CR2: 00007f45ee1f54f8 CR3: 000000003bdea000 CR4: 00000000000006e0
Mar 4 01:55:52 vlad kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Mar 4 01:55:52 vlad kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Mar 4 01:55:52 vlad kernel: Process pdflush (pid: 218, threadinfo ffff88003ea60000, task ffff88003f93b1b0)
Mar 4 01:55:52 vlad kernel: Stack:
Mar 4 01:55:52 vlad kernel: 0000000381c00000 ffff88003ea619f0 0000000000000000 0000000000000000
Mar 4 01:55:52 vlad kernel: ffff880000000001 0000000381c00000 0000000000000000 ffff88003ea619f0
Mar 4 01:55:52 vlad kernel: 000000001da5d000 0000000000001000 ffff88003ef22800 ffff88003a8214f0
Mar 4 01:55:52 vlad kernel: Call Trace:
Mar 4 01:55:52 vlad kernel: [<ffffffffa0256bae>] ? btrfs_reserve_extent+0x2e/0x52 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa026903d>] ? cow_file_range+0x1ae/0x307 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa026983f>] ? run_delalloc_range+0x9e/0x2f1 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa027c814>] ? find_lock_delalloc_range+0x124/0x17d [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa027d066>] ? __extent_writepage+0x1e3/0x791 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffff802890ff>] ? sync_buffer+0x0/0x3d
Mar 4 01:55:52 vlad kernel: [<ffffffff80312f86>] ? radix_tree_gang_lookup_tag_slot+0x7d/0xa2
Mar 4 01:55:52 vlad kernel: [<ffffffff8024d343>] ? find_get_pages_tag+0x46/0xb6
Mar 4 01:55:52 vlad kernel: [<ffffffff802387b1>] ? wake_bit_function+0x0/0x23
Mar 4 01:55:52 vlad kernel: [<ffffffffa027a95a>] ? extent_write_cache_pages+0x13c/0x242 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa027967a>] ? flush_write_bio+0x0/0x23 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa027ce83>] ? __extent_writepage+0x0/0x791 [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa027aa9b>] ? extent_writepages+0x3b/0x5c [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffffa02677c9>] ? btrfs_get_extent+0x0/0x73c [btrfs]
Mar 4 01:55:52 vlad kernel: [<ffffffff80252cf5>] ? do_writepages+0x20/0x2d
Mar 4 01:55:52 vlad kernel: [<ffffffff80284549>] ? __writeback_single_inode+0x15a/0x33b
Mar 4 01:55:52 vlad kernel: [<ffffffffa01048b2>] ? dm_any_congested+0x2f/0x39 [dm_mod]
Mar 4 01:55:52 vlad kernel: [<ffffffff80284afa>] ? generic_sync_sb_inodes+0x287/0x3e4
Mar 4 01:55:52 vlad kernel: [<ffffffff80284dbe>] ? writeback_inodes+0x68/0xa1
Mar 4 01:55:52 vlad kernel: [<ffffffff80252e10>] ? wb_kupdate+0x8b/0xfd
Mar 4 01:55:52 vlad kernel: [<ffffffff8025374b>] ? pdflush+0x0/0x1b5
Mar 4 01:55:52 vlad kernel: [<ffffffff8025374b>] ? pdflush+0x0/0x1b5
Mar 4 01:55:52 vlad kernel: [<ffffffff80253869>] ? pdflush+0x11e/0x1b5
Mar 4 01:55:52 vlad kernel: [<ffffffff80252d85>] ? wb_kupdate+0x0/0xfd
Mar 4 01:55:52 vlad kernel: [<ffffffff802383f1>] ? kthread+0x47/0x73
Mar 4 01:55:52 vlad kernel: [<ffffffff8020c07a>] ? child_rip+0xa/0x20
Mar 4 01:55:52 vlad kernel: [<ffffffff802383aa>] ? kthread+0x0/0x73
Mar 4 01:55:52 vlad kernel: [<ffffffff8020c070>] ? child_rip+0x0/0x20
Mar 4 01:55:52 vlad kernel: Code: 8b 83 b8 00 00 00 48 8d 98 48 ff ff ff 48 8b 83 b8 00 00 00 0f 18 08 48 8d 83 b8 00 00 00 48 39 c5 75 b0 4c 89 e7 e8 63 42 fe df <0f> 0b eb fe 48 83 c4 38 31 c0 5b 5d 41 5c 41 5d 41 5e 41 5f c3
Mar 4 01:55:52 vlad kernel: RIP [<ffffffffa0256b6b>] __btrfs_reserve_extent+0x296/0x2ab [btrfs]
Mar 4 01:55:52 vlad kernel: RSP <ffff88003ea618d0>
Mar 4 01:55:52 vlad kernel: ---[ end trace eb8a7132a207a474 ]---
Now, to my untrained eye, this looks like it might be an ENOSPC
problem, and thus wouldn't be entirely unexpected, except for one
thing:
hrm@vlad:~ $ df -h
Filesystem Size Used Avail Use% Mounted on
[...]
/dev/mapper/media-scratch
41G 17G 25G 42% /media/vlad/video/video
The filesystem was nowhere near full, and I wasn't expecting it to
become anywhere near full. The only thing that writes to the
filesystem is deliberately coded to leave several gigabytes of space
free.
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- Nothing wrong with being written in Perl... Some of my best ---
friends are written in Perl.
On Wed, Mar 04, 2009 at 06:06:19PM +0000, Hugo Mills wrote:
> Last night, this event jammed up a good chunk of my server:
>
> Mar 4 01:51:36 vlad kernel: btrfs searching for 1716224 bytes, num_bytes 1716224, loop 2, allowed_alloc 1
> Mar 4 01:51:36 vlad kernel: btrfs searching for 860160 bytes, num_bytes 860160, loop 2, allowed_alloc 1
> [lots of this...]
> Mar 4 01:55:52 vlad kernel: btrfs searching for 4096 bytes, num_bytes 4096, loop 2, allowed_alloc 1
> Mar 4 01:55:52 vlad kernel: btrfs allocation failed flags 1, wanted 4096
> Mar 4 01:55:52 vlad kernel: space_info has 0 free, is full
> Mar 4 01:55:52 vlad kernel: block group 12582912 has 8388608 bytes, 8388608 used 0 pinned 0 reserved
> Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
> Mar 4 01:55:52 vlad kernel: block group 1103101952 has 1073741824 bytes, 1073741824 used 0 pinned 0 reserved
> Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
> [30 more lines of this]
So yeah thats expected, you ran out of space. The key thing is this
Mar 4 01:55:52 vlad kernel: space_info has 0 free, is full
If space_info has 0 free and is full, then there is no space to allocate for it
and its completely used. I'd recommend switching to the -rc7 kernel since that
has things in place to keep this from happening as often. Thanks,
Josef
On Wed, Mar 04, 2009 at 01:50:53PM -0500, Josef Bacik wrote:
> On Wed, Mar 04, 2009 at 06:06:19PM +0000, Hugo Mills wrote:
> > Last night, this event jammed up a good chunk of my server:
> >
> > Mar 4 01:51:36 vlad kernel: btrfs searching for 1716224 bytes, num_bytes 1716224, loop 2, allowed_alloc 1
> > Mar 4 01:51:36 vlad kernel: btrfs searching for 860160 bytes, num_bytes 860160, loop 2, allowed_alloc 1
> > [lots of this...]
> > Mar 4 01:55:52 vlad kernel: btrfs searching for 4096 bytes, num_bytes 4096, loop 2, allowed_alloc 1
> > Mar 4 01:55:52 vlad kernel: btrfs allocation failed flags 1, wanted 4096
> > Mar 4 01:55:52 vlad kernel: space_info has 0 free, is full
> > Mar 4 01:55:52 vlad kernel: block group 12582912 has 8388608 bytes, 8388608 used 0 pinned 0 reserved
> > Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
> > Mar 4 01:55:52 vlad kernel: block group 1103101952 has 1073741824 bytes, 1073741824 used 0 pinned 0 reserved
> > Mar 4 01:55:52 vlad kernel: 0 blocks of free space at or bigger than bytes is
> > [30 more lines of this]
>
> So yeah thats expected, you ran out of space. The key thing is this
>
> Mar 4 01:55:52 vlad kernel: space_info has 0 free, is full
>
> If space_info has 0 free and is full, then there is no space to allocate for it
> and its completely used. I'd recommend switching to the -rc7 kernel since that
> has things in place to keep this from happening as often. Thanks,
I'll do that.
However, what's confusing me is that the filesystem was reported as
less than half full (17/41GiB used) at the time that it decided it had
no space. Is there any likely explanation for that behaviour?
I've used btrfsctl to resize it online several times: shrink by
1GiB, then enlarge by 12, 10, 10GiB. Might that have been a factor?
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- How do you become King? You stand in the marketplace and ---
announce you're going to tax everyone. If you get out
alive, you're King.