On 06/18/2014 11:35 PM, Dave Chinner wrote: > On Thu, Jun 12, 2014 at 10:28:02PM -0400, Michael L. Semon wrote: >> On 06/10/2014 01:52 AM, Dave Chinner wrote: >>> On Mon, Jun 09, 2014 at 11:21:03PM -0400, Michael L. Semon wrote: >>>> Hi! I've been running around in circles trying to work with too many >>>> ACLs, even losing my ability to count for a while. Along the way, >>>> xfs_repair from git xfsprogs (last commit around May 27) is showing >>>> the following symptoms: >>>> >>>> On v5-superblock XFS... >>>> >>>> 1) When the ACL count is just above the limit from v4-superblock XFS-- >>>> 96 is a good test figure--`xfs_repair -n` and `xfs_repair` will both >>>> end in a segmentation fault. >>> >>> I couldn't reproduce this - I suspect that this is a problem with >>> the ACL struct having a hardcoded array size or userspace not >>> having the correct padding in the on-disk structure definition and >>> you are on a 32bit system. I think I've fixed that in the patch >>> below. >> >> Maybe. Pentium III has a narrower cacheline than the Pentium 4, so >> I was not surprised to see holes in the XFS kernel code, even in the >> non-XFS kernel structs. Do I need to upgrade something (ACL, system >> kernel headers, etc.) or would a pahole trip through libxfs be more >> revealing? >> >> What I'm getting is that if xfs_repair is counting between 200 and >> 256 ACLs, it will mention that there are too many ACLs, and it will >> segfault. With your patch, the areas below and above this range are >> OK. >> >> A sample session like the one I overwrote last time looks like this: >> >> Phase 1 - find and verify superblock... >> Phase 2 - using internal log >> - zero log... >> - scan filesystem freespace and inode maps... >> - found root inode chunk >> Phase 3 - for each AG... >> - scan and clear agi unlinked lists... >> - process known inodes and perform inode discovery... >> - agno = 0 >> Too many ACL entries, count 250 >> entry contains illegal value in attribute named SGI_ACL_FILE or SGI_ACL_DEFAULT >> (segfault, either Error 4 or Error 5, forgot to bring dmesg) > > Ok, your test found a bug in the patch that was causing segv's - at > about 20 ACLs, not 250. It's not the same as what you have reported, > but it was a stack corruption bug and so may just be triggering > differently on your machines. > > Can you try the patch below? This patch works! The range from 4 ACL entries to the ACL limit seems to be fine to xfs_repair. No segfaults, and the ACL limit is OK for this case. >> Maybe not...your E-mail patch doesn't have the git version at the >> bottom, so I wondered whether I installed the entire patch. What >> I did get went through `git am` just fine, with one whitespace error. > > That's because I didn't use git directly to generate it. As you > found out, it's still a valid patch... Indeed. All is well here, and hopefully, xfs_repair is a patch or two more ready for the masses. Good work! Michael _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
