Bug 202403 - failed readahead spams syslog
Summary: failed readahead spams syslog
Status: RESOLVED CODE_FIX
Alias: None
Product: File System
Classification: Unclassified
Component: btrfs (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: BTRFS virtual assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-01-24 18:52 UTC by LimeTech
Modified: 2019-03-07 14:56 UTC (History)
1 user (show)

See Also:
Kernel Version: 4.19.16
Subsystem:
Regression: No
Bisected commit-id:

Attachments
prevent failed readhead from spamming syslog (704 bytes, text/plain)
2019-01-24 18:52 UTC, LimeTech 		Details
Add an attachment (proposed patch, testcase, etc.)

Description LimeTech 2019-01-24 18:52:24 UTC 
Created attachment 280731 [details]
prevent failed readhead from spamming syslog

Probably due to this patch:
https://www.systutorials.com/linux-kernels/771332/btrfs-readpages-should-submit-io-as-read-ahead-linux-4-19/

When underlying device driver fails a REQ_RAHEAD the btrfs_end_io() function generates a syslog message.  This patch fixes it, but maybe a btrfs developer has a better method?

-tom
Comment 1 David Sterba 2019-01-25 12:10:40 UTC 
Thanks for pointing it out, I've never seen the patch that added the REQ_RAHEAD bit as it was not CCed to the mailinglist. Readahead could fail for various reasons but should not be considered a hard error, unlike proper reads.

The proposed fix looks correct to me.
Comment 2 David Sterba 2019-03-07 14:56:33 UTC 
Patch submitted https://patchwork.kernel.org/patch/10843055/ , queued for some 5.1-rc. Thanks for the report and fix.
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