Bug 83011

Summary: BUG_ON should be eradicated from the btrfs source tree
Product: File System Reporter: Marc MERLIN (marc)
Component: btrfsAssignee: Josef Bacik (josef)
Status: NEW ---    
Severity: normal CC: rini17, szg00000
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: all Subsystem:
Regression: No Bisected commit-id:

Description Marc MERLIN 2014-08-22 14:34:50 UTC 
BUG_ON is bad:
- it prevents the traceback from being syslogged to another filesystem that hasn't crashed, or even running dmesg | ssh some_other_system if your entire system has to become read only.
- more simply, BUG_ON makes it hard to impossible to get the crash info on most average systems, so it loses the report. Even a picture of your screen is likely to miss earlier info that scrolled off
- Crashing a system because of one filesystem out of potentially many, is clearly the wrong thing to do.

Please remove all of them and convert them to WARN_ON_ONCE or equivalent, and where appropriate remount the filesystem readonly to prevent further damage (this is already done in places, but should be done everywhere).