[PATCH 00/13] netfs, cifs: Fixes to retry-related code

[Max Kellermann]

On Wed, Jul 9, 2025 at 3:01 PM David Howells <dhowells at redhat.com> wrote:
> If you keep an eye on /proc/fs/netfs/requests you should be able to see any
> tasks in there that get stuck.  If one gets stuck, then:

After one got stuck, this is what I see in /proc/fs/netfs/requests:

REQUEST  OR REF FL ERR  OPS COVERAGE
======== == === == ==== === =========
00000065 2C   2 80002020    0   0 @0000 0/0

> Looking in /proc/fs/netfs/requests, you should be able to see the debug ID of
> the stuck request.  If you can try grepping the trace log for that:
>
> grep "R=<8-digit-hex-id>" /sys/kernel/debug/tracing/trace

   kworker/u96:4-455     [008] ...1.   107.145222: netfs_sreq:
R=00000065[1] WRIT PREP  f=00 s=0 0/0 s=0 e=0
   kworker/u96:4-455     [008] ...1.   107.145292: netfs_sreq:
R=00000065[1] WRIT SUBMT f=100 s=0 0/29e1 s=0 e=0
   kworker/u96:4-455     [008] ...1.   107.145311: netfs_sreq:
R=00000065[1] WRIT CA-PR f=100 s=0 0/3000 s=0 e=0
   kworker/u96:4-455     [008] ...1.   107.145457: netfs_sreq:
R=00000065[1] WRIT CA-WR f=100 s=0 0/3000 s=0 e=0
     kworker/8:1-437     [008] ...1.   107.149530: netfs_sreq:
R=00000065[1] WRIT TERM  f=100 s=0 3000/3000 s=2 e=0
     kworker/8:1-437     [008] ...1.   107.149531: netfs_rreq:
R=00000065 2C WAKE-Q  f=80002020

I can reproduce this easily - it happens every time I log out of that
machine when bash tries to write the bash_history file - the write()
always gets stuck.

(The above was 6.15.5 plus all patches in this PR.)