[LU-17159] Mark file layouts using append striping

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Labels: easy
• Severity: 3
• Assignee: Patrick Farrell
• Reporter: Andreas Dilger

Description

While it is not necessary for functional reasons, it would be useful for debugging/diagnostic reasons to set a flag in the file layout when the MDS decides to use the append-specific layout. Otherwise, this can cause hard-to-diagnose behavior with file layouts when it overrides the default file layout.

This could set the following flag in the layout when a file is using MDS_OPEN_APPEND and dah_append_stripe_count:

enum lcm_comp_md_flags {
         :
         LCM_FL_INCOMPRESSIBLE   = 0x10,
+        LCM_FL_APPEND           = 0x20,
};

The "lfs getstripe" and other commands would need to be updated for this flag.

Issue Links

• is related to: LU-18962 sanity test_27M: lod_fill_mirrors()) ASSERTION( (!!(!lo->ldo_is_composite) == !!(lo->ldo_mirror_count == 0)) )
• is related to: LU-9341 PFL: append should not instantiate full layout
• is related to: LU-12738 PFL: append of PFL file should not instantiate full layout