[LU-13581] LU-9859 libcfs: add support for Xarray breaks build on 3.10.0-1062.9.1.el7.x86_64.debug

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Severity: 3
• Assignee: Shaun Tancheff
• Reporter: John Hammond

Description

When lockdep is enabled, the Xarray header cannot be compiled due to const qualification errors:

  CC [M]  /root/lustre-release/libcfs/libcfs/linux/xarray.o
In file included from /root/lustre-release/libcfs/libcfs/linux/xarray.c:19:0:
/root/lustre-release/libcfs/include/libcfs/linux/xarray.h: In function ‘xa_head’:
/root/lustre-release/libcfs/include/libcfs/linux/xarray.h:1135:2: error: passing argument 1 of ‘lock_is_held’ discards ‘const’ qualifier from pointer target type [-Werror]
  return rcu_dereference_check(xa->xa_head,
  ^
In file included from include/linux/spinlock_types.h:18:0,
                 from include/linux/spinlock.h:81,
                 from include/linux/mmzone.h:7,
                 from include/linux/gfp.h:5,
                 from include/linux/slab.h:12,
                 from /root/lustre-release/libcfs/libcfs/linux/xarray.c:17:
include/linux/lockdep.h:340:19: note: expected ‘struct lockdep_map *’ but argument is of type ‘const struct lockdep_map *’
 static inline int lock_is_held(struct lockdep_map *lock)
                   ^