Bug 207217 - Kernel panic when using NFS with fscache and doing any read() operation
Summary: Kernel panic when using NFS with fscache and doing any read() operation
Status: ASSIGNED
Alias: None
Product: File System
Classification: Unclassified
Component: NFS (show other bugs)
Hardware: All Linux
: P1 blocking
Assignee: David Howells
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-04-12 19:27 UTC by David Flemström
Modified: 2021-03-25 14:30 UTC (History)
3 users (show)

See Also:
Kernel Version: 5.6.3
Subsystem:
Regression: No
Bisected commit-id:


Attachments
dmesg output (4.01 KB, text/plain)
2020-04-12 19:27 UTC, David Flemström
Details

Description David Flemström 2020-04-12 19:27:32 UTC
Created attachment 288395 [details]
dmesg output

Mounting a NFS volume and then performing a write() operation on any file causes this panic to occur.  The write() of course never completes, and the calling process hangs in an unkillable state.

The mount options are:

rw,vers=4.1,fsc,async,hard,rsize=1048576,wsize=1048576,timeo=900,retrans=5,_netdev,auto,x-systemd.automount,x-systemd.device-timeout=10,timeo=14,x-systemd.requires=network-online.target,nodev,nosuid,noatime,nodiratime

See dmesg output attached
Comment 1 David Flemström 2020-04-12 19:31:28 UTC
Maybe not too surprisingly, removing the fsc mount option causes the panic to no longer happen, but of course with degraded performance.
Comment 2 David Flemström 2020-04-14 12:57:56 UTC
I misread the stack trace, apparently the crash happens with a write() and then doing a read() shortly after
Comment 3 Maxim Doucet 2021-03-25 14:30:47 UTC
This seems to be a duplicate of bug 208883 where a fix was proposed

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