[PATCH 0/3] btrfs: fix RCU string sparse noise

[Omar Sandoval <osandov@osandov.com>]

Hi everyone,

These patches clean up the big stack of sparse RCU errors I introduced into the
integration tree as reported by the kbuild test robot:

On Thu, Nov 27, 2014 at 06:45:20AM +0800, kbuild test robot wrote:
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git integration
> head:   c7a37618b60026121255c69e042d74ae5631470c
> commit: 37aad79d90a0cbf82a5eda62dfe3af4241f5aca3 [38/39] Move BTRFS RCU string to common library
> reproduce:
>   # apt-get install sparse
>   git checkout 37aad79d90a0cbf82a5eda62dfe3af4241f5aca3
>   make ARCH=x86_64 allmodconfig
>   make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> fs/btrfs/check-integrity.c:848:25: sparse: incorrect type in argument 1 (different address spaces)
>    fs/btrfs/check-integrity.c:848:25:    expected struct rcu_string [noderef] <asn:4>*rcu_str
>    fs/btrfs/check-integrity.c:848:25:    got struct rcu_string *name
[snip, there's a lot of these]

As payment for my transgressions, this also clean ups the existing rcu_string
usage to get rid of the preexisting noise.

The first patch fixes the __rcu annotations which I got wrong on the first go.
The second fixes an incorrect use of RCU in the BTRFS_IOC_DEV_INFO ioctl. The
third refactors the volume code's usage of rcu_string, fixing a questionable
RCU or two in the process.

This patch series applies to Chris' integration branch.

Thanks!

Omar Sandoval (3):
  rcustring: clean up botched __rcu annotations
  btrfs: fix suspicious RCU in BTRFS_IOC_DEV_INFO
  btrfs: refactor btrfs_device->name updates

 fs/btrfs/ioctl.c          | 10 ++---
 fs/btrfs/volumes.c        | 93 ++++++++++++++++++++++++++++++++---------------
 fs/btrfs/volumes.h        |  2 +-
 include/linux/rcustring.h |  5 +--
 4 files changed, 72 insertions(+), 38 deletions(-)

-- 
2.1.3