Zfs: PANIC in dbuf_clear_data()

[behlendorf]

System information

Type | Version/Name
--- | ---
Distribution Name | gentoo
Distribution Version |
Linux Kernel | 4.20.17-gentoo
Architecture | amd64
ZFS Version | 0.8.0-rc3_131_ge03b25a5

Describe the problem you're observing

System panic during zfs recv - same system that experienced #8168.

This is a duplicate of #8551.

Describe how to reproduce the problem

Receive unencrypted filesystem:

$ zfs send -wLvc -p -c -I olympic/HOME/curt@1551326401 olympic/HOME/curt@1554019201
$ zfs recv -sFv -o :autosnapshot=disabled -o readonly=on -o canmount=on -o mountpoint=/home/curt/backup//home/curt -o special_small_blocks=0 rpool/backup/millennium/olympic/HOME/curt

Include any warning/errors/backtraces from the system logs

[11522.141836] PANIC at dbuf.c:1090:dbuf_clear_data()
[11522.141885] Showing stack for process 29104
[11522.141888] CPU: 9 PID: 29104 Comm: receive_writer Tainted: P           O      4.20.17-gentoo #1
[11522.141890] Hardware name: Supermicro X9SRA/X9SRA-3/X9SRA/X9SRA-3, BIOS 3.2 01/16/2015
[11522.141891] Call Trace:
[11522.141900]  dump_stack+0x70/0x9a
[11522.141911]  spl_dumpstack+0x29/0x2b [spl]
[11522.141917]  spl_panic+0xd3/0xfb [spl]
[11522.142042]  dbuf_clear_data+0x58/0xa0 [zfs]
[11522.142084]  dmu_buf_will_fill+0x1f9/0x3a0 [zfs]
[11522.142125]  dmu_buf_write_embedded+0x86/0x310 [zfs]
[11522.142169]  dmu_write_embedded+0xa4/0x180 [zfs]
[11522.142273]  receive_process_record+0x497/0xb70 [zfs]
[11522.142336]  receive_writer_thread+0xaf/0x220 [zfs]
[11522.142433]  thread_generic_wrapper+0x7d/0xc0 [spl]
[11522.142437]  kthread+0x120/0x140

[ahrens]

I think @tcaputi is investigating a fix for this.

[behlendorf]

Closing. This issue is a duplicate of #8551 which was closed for the reason detailed in this https://github.com/zfsonlinux/zfs/issues/8551#issuecomment-483432226.