[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)
                   ^

Comments

[Peter Jones]

Landed for 2.14

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/39150/
Subject: LU-13581 build: xarray and lockdep_is_held const clash
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 3fcceea0e301c51a29d641c287bd36302a706bbe

[Gerrit Updater]

Shaun Tancheff ([e-mail]) uploaded a new patch: https://review.whamcloud.com/39150
Subject: LU-13581 build: xarray and lockdep_is_held const clash
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 1902c60cf81363fb6635f4f5729d0874581e1b75

[Gerrit Updater]

James Simmons ([e-mail]) uploaded a new patch: https://review.whamcloud.com/38696
Subject: LU-13581 libcfs: fixup Xarray support
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: afc399c9aa540928f755fb8a21455c51bb7bf353

[John Hammond]

The signature of the lockdep functions changed sometime between 3.10 and 5.2. See https://elixir.bootlin.com/linux/v5.2-rc2/source/include/linux/lockdep.h#L354

[James A Simmons]

Strange this doesn't show up in the linux kernel since it was taken from it.