[LU-9362] PFL: Files with multiple components should not return multiple values for ‘lfs getstripe’

• Type: Technical task
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.10.0
• Affects Version/s: Lustre 2.10.0
• Labels: pfl
• Assignee: Zhenyu Xu
• Reporter: James Nunez (Inactive)

Description

Recent testing on master with files with multiple components show that several tests fail due to ‘lfs getstripe’ with the index or the stripe count flags return multiple lines of output. If this impacts the Lustre test suites, this could impact exiting tools that use ‘lfs getstripe’ and expect output of a single value.

To demonstrate this, we have a file with three components:

[root@eagle-48vm6 ]# lfs getstripe /lustre/scratch/d9.sanity/d2/d3
/lustre/scratch/d9.sanity/d2/d3
  lcm_layout_gen:  0
  lcm_entry_count: 3
    lcme_id:             N/A
    lcme_flags:          0
    lcme_extent.e_start: 0
    lcme_extent.e_end:   2097152
      stripe_count:  1       stripe_size:   1048576       stripe_offset: -1
    lcme_id:             N/A
    lcme_flags:          0
    lcme_extent.e_start: 2097152
    lcme_extent.e_end:   16777216
      stripe_count:  2       stripe_size:   2097152       stripe_offset: -1
    lcme_id:             N/A
    lcme_flags:          0
    lcme_extent.e_start: 16777216
    lcme_extent.e_end:   EOF
      stripe_count:  4       stripe_size:   4194304       stripe_offset: -1
[root@eagle-48vm6 ]# lfs getstripe -i /lustre/scratch/d9.sanity/d2/d3
-1
-1
-1
[root@eagle-48vm6 ]# lfs getstripe -c /lustre/scratch/d9.sanity/d2/d3
1
2
4

Andreas Dilger has commented on this issue:

"lfs getstripe -c" should return a single value for the stripe count. In the design, this was the stripe count of the last instantiated component, since that is the best estimate for the number of stripes for the given file. In the implementation (AFAIK) it was the sum of all the instantiated stripe counts, which is also reasonable.

The following tests fail due to expecting a single value from ‘lfs getstripe’.
sanity test 27i, 27w, 27A - https://testing.hpdd.intel.com/test_sets/5cc43d3c-23b8-11e7-8920-5254006e85c2

Issue Links

• has to be finished together with: LU-9359 sanity test_27p: /mnt/lustre/d27p.sanity/f27p.sanity has size 4, not 80000004
• is related to: LU-9424 ‘lfs getstripe --component-count’ return nothing for non-composite files
• is related to: LU-8998 Progressive File Layout (PFL)