[LU-3602] make utility functions availalbe to user space

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Labels: llnl
• Assignee: Lai Siyao
• Reporter: Ned Bass (Inactive)

Description

In LU-2973 we decided that user-space callers of lgetxattr() should be responsible for swabbing the value of "lustre.lov" as needed. This issue is to discuss how best to make utility functions (for swabbing, comparing, etc. of data structures like lov_user_md and lu_fid) available to both kernel and user space.

The swabbing functions are implemented in ptlrpc/pack_generic.c with extern declarations in lustre_idl.h. While these are compiled in a user-space library if liblustre is enabled, it would be nice to make them available in a generic way for liblustreapi (i.e. for LU-2182). That is, liblustre should not be a dependency for liblustreapi. Perhaps such utility functions can be refactored into a generic library that can be linked to from kernel and user code.

Issue Links

• is related to: LU-2182 Add llapi_file_get_layout() function in liblustreapi
• is related to: LU-2973 lov_mds_md not swabbed in ll_getxattr
• is related to: LU-5969 Create an LGPL version of liblustreapi