[LU-15609] Client should not assume RDONLY implies SOM

Related — Fri, 22 Jul 2022 20:37:16 +0000

In lov_io_slice_mirror_init, the client code assumes that a RDONLY flag in the layout implies SOM and skips glimpse if so. This is something like a layering violation - SOM is communicated from the MDS when it is valid, and the client already skips glimpse in that case.

Prior to "~~LU-14526~~ flr: mirror split downgrade SOM"/https://review.whamcloud.com/43168/, this was incorrect but not a problem, because LCM_FL_RDONLY always implied valid SOM. That patch made that assumption invalid.

Fix is for client not to assume LCM_FL_RDONLY means SOM.

Whamcloud Community JIRA

[LU-15609] Client should not assume RDONLY implies SOM