There is no need for testing. The bug is documented. Someone made the decision to crash the code rather than handle the condition. See the git commit below.
BUG_ON(meta_ac == NULL); Some information is in a January posting to this list from Ben Hutchings. https://oss.oracle.com/pipermail/ocfs2-devel/2017-January/012701.html ++++++ meta_ac is passed down from ocfs2_dio_end_io_write(), which allocates it using ocfs2_lock_allocators()... but the latter only allocates it conditionally. It seems like the condition is wrong somehow. ++++++ Additional insight was provided by Ian Campbell in March. It was sent this list, but I do not see it in the archive. ++++++ This still seems to be happening for this user with 4.9.13, looking at "git log -p v4.9.13..origin/master -- fs/ocfs2" I wonder if https://git.kernel.org/torvalds/c/3e10b793fc40dfdbe51762e0d084bd6f2c8acaaa might be relevant? The commit message mentions meta_ac not getting allocated and an extent split vs refcount split differentiation and we have ocfs2_split_extent in the trace. Slim reasoning I know, maybe someone who knows the code could make a better determination. ++++++ -- Russell Mosemann IT Manager | Future Foam, Inc. 1610 Avenue N | Council Bluffs, IA 51501-1071 O: (712) 323-9122 Ext 228 F: (712) 323-0158 -----Original Message----- From: "Gang He" <g...@suse.com> Sent: Thursday, May 18, 2017 2:11am To: rmosem...@futurefoam.com, ocfs2-devel@oss.oracle.com Subject: Re: [Ocfs2-devel] kernel BUG at ocfs2/alloc.c:1514 Hello Russell, I just went through the bug description from the link below, Could you always meet this issue in your testing environment? since it looks like a simple direct write. Second, could you describe the whole reproduce steps in details or provide a testing script which can make this bug happen? Because, in our normal environment, I believe we can not meet this bug easily since the kernel version v4.9 is very new. Thanks Gang >>> > Copious stack traces available at > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=841144 > > > -- > Russell Mosemann > IT Manager | Future Foam, Inc. > 1610 Avenue N | Council Bluffs, IA 51501-1071 > O: (712) 323-9122 Ext 228 > F: (712) 323-0158 _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel