It worked fine with 4.4.0.62 (Ubuntu Xenial) kernel.

Thanks!

On Fri, Feb 17, 2017 at 9:48 PM, Eric Wheeler [off-list ref] wrote:

On Fri, 17 Feb 2017, shiva rkreddy wrote:

quoted

Hi Eric:

Kernel version: 4.2.0.42

It was 3.13 (Ubuntu Trusty) kernel that was upgraded to Ubuntu
"linux-generic-lts-wily". This upgrade made the kernel version to
4.2.0.42.
The devices were created after kernel upgrade to 4.2.0.42.

I'm not sure what Ubuntu has patched in, and 4.2 isn't a supported
upstream kernel.  Try 4.1.38 or 4.4.49.

--
Eric Wheeler

quoted

I can reproduce and provide more details if needed.

This was the whole backtrace from dmesg:

===
[ 53.752177] bcache: register_cache() registered cache device nvme0n1p17
[ 58.641878] bcache: register_bdev() registered backing device sdj
[ 253.701153] INFO: task bcache_allocato:496 blocked for more than 120 seconds.
[ 253.953639] bcache_allocato D ffff88085fe16640 0 496 2 0x00000000
[ 253.953670] [<ffffffffc01311e3>] bch_bucket_alloc+0x163/0x320 [bcache]
[ 253.953682] [<ffffffffc014fa36>] ? bch_crc64+0x36/0x50 [bcache]
[ 253.953689] [<ffffffffc0146de4>] bch_prio_write+0x184/0x310 [bcache]
[ 253.953693] [<ffffffffc0131019>] bch_allocator_thread+0x3d9/0x440 [bcache]
[ 253.953699] [<ffffffffc0130c40>] ? invalidate_buckets+0x920/0x920 [bcache]
[ 253.953716] INFO: task bcache-register:525 blocked for more than 120 seconds.
[ 254.206187] bcache-register D ffff88085fe16640 0 525 1 0x00000004
[ 254.206202] [<ffffffffc01311e3>] bch_bucket_alloc+0x163/0x320 [bcache]
[ 254.206208] [<ffffffffc013152c>] __bch_bucket_alloc_set+0xec/0x140 [bcache]
[ 254.206213] [<ffffffffc01315ce>] bch_bucket_alloc_set+0x4e/0x70 [bcache]
[ 254.206218] [<ffffffffc0145866>] __uuid_write+0x46/0xe0 [bcache]
[ 254.206223] [<ffffffffc0146806>] bch_uuid_write+0x16/0x40 [bcache]
[ 254.206228] [<ffffffffc0147493>] bch_cached_dev_attach+0x153/0x490 [bcache]
[ 254.206249] [<ffffffffc0149645>] register_bcache+0xa25/0x13b0 [bcache]
[ 254.206317] INFO: task bcache-register:527 blocked for more than 120 seconds.
[ 254.458788] bcache-register D ffff88105f456640 0 527 1 0x00000004
[ 254.458812] [<ffffffffc0148e5e>] register_bcache+0x23e/0x13b0 [bcache]
[ 254.458832] INFO: task bcache-register:548 blocked for more than 120 seconds.
[ 254.711311] bcache-register D ffff88105f456640 0 548 1 0x00000004
===

Thanks
Shiva

On Fri, Feb 17, 2017 at 5:57 PM, Eric Wheeler [off-list ref] wrote:

quoted

Hi Shiva,

What kernel version?

Also, see if you can paste the trace without wrapping and include the
whole backtrace including kernel version and line numbers if any.

--
Eric Wheeler

On Fri, 17 Feb 2017, shiva rkreddy wrote:

quoted

Greetings to all!

I'm experimenting bcache with sas disks as backing devices and nvme as
cache. The backing devices are used as ceph osd mount points.
I was able to make them part of ceph cluster and have the ceph mount
points added to fstab using the bcache uuid.

These bcache backing devices are disappearing after rebooting the host
that has these devices. dmesg shows, bcache_allocto blocked and later
bcache-register blocked.
bcache cache device is registered successfully though.

Digged the mailing list and couldn't find consumable information. Did
anyone encounter this problem ? Any thoughts on troubleshooting ..

Appreciate your help!

Here is excerpt from dmesg:

[   53.752029] bcache: bch_journal_replay() journal replay done, 2173
keys in 153 entries, seq 331031
                                   │

[   53.752177] bcache: register_cache() registered cache device
nvme0n1p17
                                         │

[   58.641878] bcache: register_bdev() registered backing device sdj

                                  │

[  253.701153] INFO: task bcache_allocato:496 blocked for more than
120 seconds.
                                     │

[  253.953639] bcache_allocato D ffff88085fe16640     0   496      2
0x00000000
                                    │

[  253.953670]  [<ffffffffc01311e3>] bch_bucket_alloc+0x163/0x320
[bcache]
                                       │

[  253.953682]  [<ffffffffc014fa36>] ? bch_crc64+0x36/0x50 [bcache]

                                  │

[  253.953689]  [<ffffffffc0146de4>] bch_prio_write+0x184/0x310
[bcache]
                                         │

[  253.953693]  [<ffffffffc0131019>] bch_allocator_thread+0x3d9/0x440
[bcache]
                                   │

[  253.953699]  [<ffffffffc0130c40>] ? invalidate_buckets+0x920/0x920
[bcache]
                                   │

[  253.953716] INFO: task bcache-register:525 blocked for more than
120 seconds.
                                     │

[  254.206187] bcache-register D ffff88085fe16640     0   525      1
0x00000004
                                    │

[  254.206202]  [<ffffffffc01311e3>] bch_bucket_alloc+0x163/0x320
[bcache]
                                       │

[  254.206208]  [<ffffffffc013152c>] __bch_bucket_alloc_set+0xec/0x140
[bcache]
                                  │

[  254.206213]  [<ffffffffc01315ce>] bch_bucket_alloc_set+0x4e/0x70
[bcache]
                                     │

[  254.206218]  [<ffffffffc0145866>] __uuid_write+0x46/0xe0 [bcache]

                                  │

[  254.206223]  [<ffffffffc0146806>] bch_uuid_write+0x16/0x40 [bcache]

                                  │

[  254.206228]  [<ffffffffc0147493>] bch_cached_dev_attach+0x153/0x490
[bcache]
                                  │

[  254.206249]  [<ffffffffc0149645>] register_bcache+0xa25/0x13b0
[bcache]
                                       │

[  254.206317] INFO: task bcache-register:527 blocked for more than
120 seconds.
                                     │

[  254.458788] bcache-register D ffff88105f456640     0   527      1
0x00000004
                                    │

[  254.458812]  [<ffffffffc0148e5e>] register_bcache+0x23e/0x13b0
[bcache]
                                       │

[  254.458832] INFO: task bcache-register:548 blocked for more than
120 seconds.
                                     │

[  254.711311] bcache-register D ffff88105f456640     0   548      1 0x00000004
--
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