Re: XFS LTS backport cabal

[Chandan Babu R <chandan.babu@oracle.com>]

On Thu, May 26, 2022 at 08:01:22 AM -0700, Leah Rumancik wrote:
> On Wed, May 25, 2022 at 02:23:10PM -0700, Darrick J. Wong wrote:
>> Hi everyone,
>> 
>> 3. fstesting -- new patches proposed for stable branches shouldn't
>> introduce new regressions, and ideally there would also be a regression
>> test that would now pass.  As Dave and I have stated in the past,
>> fstests is a big umbrella of a test suite, which implies that A/B
>> testing is the way to go.  I think at least Zorro and I would like to
>> improve the tagging in fstests to make it more obvious which tests
>> contain enough randomness that they cannot be expected to behave 100%
>> reliably.
> It would be nice to find an agreement on testing requirements. I have
> attached some ideas on configs/number of tests/etc as well as the status
> of my work on 5.15 below.
>
>
>> a> I've been following the recent fstests threads, and it seems to me
>> that there are really two classes of users -- sustaining people who want
>> fstests to run reliably so they can tell if their backports have broken
>> anything; and developers, who want the randomness to try to poke into
>> dusty corners of the filesystem.  Can we make it easier to associate
>> random bits of data (reliability rates, etc.) with a given fstests
>> configuration?  And create a test group^Wtag for the tests that rely on
>> RNGs to shake things up?
> This would be great!
>
>> 
>> 
>> Thoughts? Flames?
>> 
>> --D
> This thread had good timing :) I have been working on setting up 
> some automated testing. Currently, 5.15.y is our priority so I have 
> started working on this branch.
>
> Patches are being selected by simply searching for the “Fixes” 
> tag and applying if the commit-to-be-fixed is in the stable branch, 
> but AUTOSEL would be nice, so I’ll start playing around with that. 
> Amir, it would be nice to sync up the patch selection process. I can 
> help share the load, especially for 5.15.
>
> Selecting just the tagged “Fixes” for 5.15.y for patches through 
> 5.17.2, 15 patches were found and applied - if there are no 
> complaints about the testing setup, I can go ahead and send out this 
> batch:
>
> c30a0cbd07ec xfs: use kmem_cache_free() for kmem_cache objects
> 5ca5916b6bc9 xfs: punch out data fork delalloc blocks on COW writeback failure
> a1de97fe296c xfs: Fix the free logic of state in xfs_attr_node_hasname
> 1090427bf18f xfs: remove xfs_inew_wait
> 089558bc7ba7 xfs: remove all COW fork extents when remounting readonly
> 7993f1a431bc xfs: only run COW extent recovery when there are no live extents
> 09654ed8a18c xfs: check sb_meta_uuid for dabuf buffer recovery
> f8d92a66e810 xfs: prevent UAF in xfs_log_item_in_current_chkpt
> b97cca3ba909 xfs: only bother with sync_filesystem during readonly remount
> eba0549bc7d1 xfs: don't generate selinux audit messages for capability testing
> e014f37db1a2 xfs: use setattr_copy to set vfs inode attributes
> 70447e0ad978 xfs: async CIL flushes need pending pushes to be made stable
> c8c568259772 xfs: don't include bnobt blocks when reserving free block pool
> cd6f79d1fb32 xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks
> 919edbadebe1 xfs: drop async cache flushes from CIL commits.
>

In our experience, we found that some of the patches which fix bugs would not
have the associated "Fixes" tag. Hence I am currently using the script
https://gist.github.com/chandanr/c1e3affdb06eb2e025f955e7a77b2338 to identify
such commits along with the commits which have the "Fixes" tag.

The following command line obtains the list of commits from v5.18,

# list-xfs-fix-commits.sh v5.17 v5.18
--- Actual fixes ---
1:  eba0549bc7d10
2:  e014f37db1a2d
3:  70447e0ad9781
4:  c8c5682597727
5:  cd6f79d1fb324
6:  919edbadebe17
7:  9a5280b312e2e

---- Possible fixes; Along with matching regex  ----
1:  871b9316e7a77: bug
2:  41667260bc84d: bug
3:  83a44a4f47ad2: fix
4:  a9a4bc8c76d74: rac.+
5:  dbd0f5299302f: rac.+
6:  941fbdfd6dd0f: rac.+
7:  01728b44ef1b7: bug
8:  b9b1335e64030: fix
9:  82be38bcf8a2e: fix
10:  d2d7c0473586d: fix
11:  ab9c81ef321f9: assert
12:  b5f17bec1213a: rac.+
13:  41e6362183589: fix
14:  3c4cb76bce438: rac.+
15:  5652ef31705f2: fail

I go through each commit in the "Possible fixes" section and determine if any
of those need to be backported.

-- 
chandan