Hey, I just got a deadlock on Linux 3.18.5. It occurred while processing a some data: All in all reading from the btrfs volume, decompressing it (the bottleneck in this process), doing some calculations and finally writing the results back to a new file on the volume. I am using a freshly installed Ubuntu 14.04 in a virtual machine. The block device used for btrfs is a LVM volume offered by the KVM hypervisor. Unfortunately I was using an old version of my user space tools (Version 3.12-1), so it might be related to that? The volume was mounted with the following mount options: > default,compress-force=lzo,subvol=data Related kernel stack trace: > Feb 4 22:00:41 qdock03 kernel: [22560.284120] INFO: task btrfs-transacti:508 blocked for more than 120 seconds. > Feb 4 22:00:41 qdock03 kernel: [22560.284200] Tainted: G W 3.18.5-031805-generic #201501292218 > Feb 4 22:00:41 qdock03 kernel: [22560.284267] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > Feb 4 22:00:41 qdock03 kernel: [22560.284339] btrfs-transacti D 0000000000000001 0 508 2 0x00000000 > Feb 4 22:00:41 qdock03 kernel: [22560.284345] ffff881ece617b28 0000000000000046 ffffffffc0136e90 00000000008bee9a > Feb 4 22:00:41 qdock03 kernel: [22560.284349] ffff881ece617fd8 0000000000013640 ffff881ece095b00 0000000000013640 > Feb 4 22:00:41 qdock03 kernel: [22560.284352] ffff881ed0638000 ffff881ecfdf5000 ffff881ece617b98 ffff881f79c33f40 > Feb 4 22:00:41 qdock03 kernel: [22560.284356] Call Trace: > Feb 4 22:00:41 qdock03 kernel: [22560.284397] [<ffffffffc0136e90>] ? btree_io_failed_hook+0x60/0x60 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284406] [<ffffffff817b0750>] ? bit_wait_timeout+0x80/0x80 > Feb 4 22:00:41 qdock03 kernel: [22560.284411] [<ffffffff817afd29>] schedule+0x29/0x70 > Feb 4 22:00:41 qdock03 kernel: [22560.284415] [<ffffffff817afdff>] io_schedule+0x8f/0xd0 > Feb 4 22:00:41 qdock03 kernel: [22560.284419] [<ffffffff817b077c>] bit_wait_io+0x2c/0x50 > Feb 4 22:00:41 qdock03 kernel: [22560.284423] [<ffffffff817b04e5>] __wait_on_bit+0x65/0x90 > Feb 4 22:00:41 qdock03 kernel: [22560.284428] [<ffffffff8117888b>] ? find_get_pages_tag+0xcb/0x170 > Feb 4 22:00:41 qdock03 kernel: [22560.284449] [<ffffffffc015ce8e>] ? clear_state_bit+0xae/0x170 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284455] [<ffffffff81177e37>] wait_on_page_bit+0xc7/0xd0 > Feb 4 22:00:41 qdock03 kernel: [22560.284460] [<ffffffff810b4cf0>] ? wake_atomic_t_function+0x40/0x40 > Feb 4 22:00:41 qdock03 kernel: [22560.284465] [<ffffffff81178004>] filemap_fdatawait_range+0xf4/0x180 > Feb 4 22:00:41 qdock03 kernel: [22560.284483] [<ffffffffc013f41f>] btrfs_wait_marked_extents+0x8f/0x140 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284498] [<ffffffffc013f532>] btrfs_write_and_wait_transaction+0x62/0xb0 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284514] [<ffffffffc013fe04>] btrfs_commit_transaction+0x734/0xae0 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284528] [<ffffffffc013d4d5>] transaction_kthread+0x1d5/0x250 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284543] [<ffffffffc013d300>] ? open_ctree+0x1f50/0x1f50 [btrfs] > Feb 4 22:00:41 qdock03 kernel: [22560.284548] [<ffffffff81093a79>] kthread+0xc9/0xe0 > Feb 4 22:00:41 qdock03 kernel: [22560.284552] [<ffffffff810939b0>] ? flush_kthread_worker+0x90/0x90 > Feb 4 22:00:41 qdock03 kernel: [22560.284556] [<ffffffff817b3ebc>] ret_from_fork+0x7c/0xb0 > Feb 4 22:00:41 qdock03 kernel: [22560.284559] [<ffffffff810939b0>] ? flush_kthread_worker+0x90/0x90 Regards, Juergen-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
