On Tue, Aug 30, 2016 at 10:25:13AM +1000, Dave Chinner wrote: > On Mon, Aug 29, 2016 at 06:47:04PM -0500, Bill O'Donnell wrote: > > On Tue, Aug 30, 2016 at 09:40:44AM +1000, Dave Chinner wrote: > > > On Mon, Aug 29, 2016 at 06:26:15PM -0500, Bill O'Donnell wrote: > > > > On Tue, Aug 30, 2016 at 09:12:06AM +1000, Dave Chinner wrote: > > > > > On Mon, Aug 29, 2016 at 08:40:12AM -0500, Bill O'Donnell wrote: > > > > > > Commits b20b6c2 and 29647c8 modified xfs_quota for use on > > > > > > non-XFS filesystems. One modification in fs_initialise_mounts > > > > > > (paths.c) resulted in an xfstest fail (xfs/261), due to foreign > > > > > > fs paths entering the fs table. > > > > > > > > > > What's the failure? I'm not seeing it here on any of my test > > > > > machines... > > > > > > > > On my box, there are a few ext4 mounts, and test xfs/261 > > > > populates the fs table with those paths. > > > > > > I have ext2 and ext3 mounts on these machines as well, and they > > > don't throw any errors. > > > > > > > So when xfs_quota commands > > > > in 261 are executed, a "foreign filesystem" message is thrown. > > > > > > What is the output that is causing the failure? When someone > > > asks you to describe the error that is occurring, please quote the > > > /exact error/ that is occurring - describing it via paraphrasing > > > does not tell anything useful about the error as I cannot correlate > > > that description to the code that is throwing it. > > > > Ahh, ok, I'm sorry about that. > > [root@dell-pesc440-01 xfstests-dev]# ./check -d tests/xfs/261 > > FSTYP -- xfs (debug) > > PLATFORM -- Linux/x86_64 dell-pesc440-01 4.7.0-rc108052016bill02+ > > MKFS_OPTIONS -- -f -bsize=4096 /dev/mapper/fedora_dell--pesc440--01-csdf > > MOUNT_OPTIONS -- -o context=system_u:object_r:nfs_t:s0 /dev/mapper/fedora_dell--pesc440--01-csdf /mnt/scratch > > > > xfs/261 2s ...QA output created by 261 > > Silence is golden. > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > print command is for XFS filesystems only > > Bill, slow down and work through the code from first principles. I > don't care about getting a fix quickly - I care about the process > you use to find the problem and whether you end up fully > understanding the problem. Walk through the code in the debugger if > you have to - it will show you the flow and how the pieces connect > together. > > The question that needs to be answered is this: what set of initial > conditions is causing this error to occur? We don't really care > about what previous changes caused the issue at this point - working > that out comes /after/ diagnosing the problem when we are trying to > work out a fix. > > So, yes, the issue occurs because there are foreign fs types in the > fstable, but that's not the underlying problem nor the problem that > needs to be solved. > > Use the debugger and cssope to connect the dots between the fstable > initialisation, the fs_path initialisation, and the function that > prints that error. That should give you a good idea of why the error > is being printed. > > Then have a look at print_f() and see what it does with the fstable. > Then tell me whether we should even care about checking for foreign > filesystems before we run the print_f command. At this point, the > fix should be obvious. I used gdb to check the flow, and realized that instead of modifying paths.c, it makes sense to simply allow the print (and paths) command regardless of whether or not the fs is foreign or not. So to that end, no, we shouldn't care about checking for foreign fs before print_f. This will dispense with the notion of involving foreign_allowed in libxcmd/paths.c. That's fine, but I'm still a bit stymied understanding the original intent for the "-f" flag. Did we not want to remind the user that one must use -f when using xfs_quota on a foreign fs (exceptions being help and quit)? Also, I had thought adding "-f" was to ensure that the default behavior of xfs_quota didn't change in the face of other filesystems. Wouldn't not populating the fs table with foreign fs entries be the simplest way to ensure that no "print all the info" options which iterate over the table will change their output? > > And then have a look at printpath() and tell me what the foriegn > filesystem handling bug it contains. Other than some minor output formatting issues, I've not been able to discover a bug in printpath(). I'm obviously missing something ;) Thanks- Bill > > And, yes, I could have written and tested the patch to fix all this > in the time it took to write this email, but then you don't have the > opportunity to learn from doing it.... > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
