failed to linearize skb with tiny unaligned fragment

After previous (to 4.6.2-1-ARCH) kernel update, when I try to watch films from my Excito B3 (Kodi on RPi3 via NFS), the film will get stuck a few times, and then will cause B3 to die - only hard reboot helps. I updated the kernel to newest version (4.6.3-1-ARCH) yesterday, but the issue persists.

In the log, I get a ton of those: (few hundred per second):

$this->bbcode_second_pass_quote('', '[')root@archb3 ~]# journalctl -r | grep skb | head -n1
Jun 24 18:02:28 archb3 kernel: mv643xx_eth_port mv643xx_eth_port.1 eth1: failed to linearize skb with tiny unaligned fragment

[moonman]

Well, seems the problem is back. I had removed the patch that disabled TSO in 4.6.0-2 as after testing and some digging in commits in mainline it seemed the problem was fixed In 4.5.x releases. Obviously it is not.. I will readd the patch back so expect this to be fixed shortly. Thanks for the report

[stasheck]

You rock!

I don't know if that's of any use, but I noticed that the issue happens only after some time, and seems more related to time than to amount of data transferred:
- directly after reboot, I was able to stream 2 episodes of a TV series, each about 1 hr and >2 GB in size, and the problem only appeared on 3rd episode
- on the next day, issue started within minutes of starting an episode, and while I haven't checked - knowing my network, much less than 4 GB of data flew through the interface before that.

[moonman]

Please test linux-kirkwood-dt-4.6.3-2.

Thanks for quick turnaround!

I noticed today that my Transmission is failing with "not enough space on drive", even though there's 100 GB+ of space. Checking journal, I found this - for -2 and for -1 kernel, I'm not sure if it's related, but for -1 kernel it was right next to "failed to linearize..." lines:

$this->bbcode_second_pass_quote('', 'J')ul 01 13:40:19 archb3 kernel: ---[ end trace 210c701fffeb29b3 ]---
Jul 01 13:40:19 archb3 kernel: [<c013d1c4>] (SyS_pwrite64) from [<c000a4a0>] (ret_fast_syscall+0x0/0x38)
Jul 01 13:40:19 archb3 kernel: [<c013c008>] (vfs_write) from [<c013d1c4>] (SyS_pwrite64+0x7c/0x94)
Jul 01 13:40:19 archb3 kernel: [<c013b0c8>] (new_sync_write) from [<c013c008>] (vfs_write+0x90/0x1a4)
Jul 01 13:40:19 archb3 kernel: [<bf168ae0>] (btrfs_file_write_iter [btrfs]) from [<c013b0c8>] (new_sync_write+0x84/0xac)
Jul 01 13:40:19 archb3 kernel: [<bf1639a8>] (__btrfs_buffered_write [btrfs]) from [<bf168ae0>] (btrfs_file_write_iter+0x1e4/0x6f8 [btrfs])
Jul 01 13:40:19 archb3 kernel: [<bf12798c>] (btrfs_free_reserved_data_space [btrfs]) from [<bf1639a8>] (__btrfs_buffered_write+0x554/0x7bc [btrfs])
Jul 01 13:40:19 archb3 kernel: [<bf127930>] (btrfs_free_reserved_data_space_noquota [btrfs]) from [<bf12798c>] (btrfs_free_reserved_data_space+0x24/0x44 [btrfs])
Jul 01 13:40:19 archb3 kernel: [<c001f38c>] (warn_slowpath_null) from [<bf127930>] (btrfs_free_reserved_data_space_noquota+0x160/0x198 [btrfs])
Jul 01 13:40:19 archb3 kernel: [<c001f2b4>] (__warn) from [<c001f38c>] (warn_slowpath_null+0x20/0x28)
Jul 01 13:40:19 archb3 kernel: [<c000da38>] (show_stack) from [<c001f2b4>] (__warn+0xdc/0x104)
Jul 01 13:40:19 archb3 kernel: [<c00105e4>] (unwind_backtrace) from [<c000da38>] (show_stack+0x10/0x14)
Jul 01 13:40:19 archb3 kernel: Hardware name: Marvell Kirkwood (Flattened Device Tree)
Jul 01 13:40:19 archb3 kernel: CPU: 0 PID: 445 Comm: transmission-da Tainted: G W 4.6.3-2-ARCH #1
Jul 01 13:40:19 archb3 kernel: Modules linked in: cfg80211 rfkill bridge stp llc ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_tcpudp xt_multiport xt_recent xt_conntrack nf_connt
Jul 01 13:40:19 archb3 kernel: WARNING: CPU: 0 PID: 445 at fs/btrfs/extent-tree.c:4233 btrfs_free_reserved_data_space_noquota+0x160/0x198 [btrfs]
Jul 01 13:40:18 archb3 kernel: ------------[ cut here ]------------