Re: [PATCH RESEND v8 0/3] Introduce RCU string API

[Omar Sandoval <osandov@osandov.com>]

On Sat, Jan 10, 2015 at 11:56:48AM -0800, Paul E. McKenney wrote:
> On Fri, Jan 09, 2015 at 12:35:57PM -0800, Omar Sandoval wrote:
> > Hi, everyone,
> > 
> > Now that the merge window and the holidays are over, I've rebased this on
> > v3.19-rc3 for the next merge window.
> 
> Wasn't btrfs going to take this one?
> 
> If I am supposed to take it, please split out the RCU infrastructure
> portion so that I can push it separately.
> 
> 							Thanx, Paul
> 
> > This patch series introduces the RCU string API and cleans up the wreckage of
> > sparse warnings which follow from it (shown here from when the patch was
> > briefly in the btrfs integration tree):
> > 
> > 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]
> > 
> > Version 8 combines the original patch with another patch series I posted to fix
> > these warnings, which fixes the botched __rcu annotations that caused some of
> > the warnings and refactors the existing uses of rcustring to get rid of the
> > rest. There's also a patch to fix an RCU misuse.
> > 
> > Thanks!
> > 
> > v8: Get the __rcu annotations right, clean up RCU string-related sparse noise
> > v7: Add arguments to kernel doc for printk wrappers, use ##__VA_ARGS
> > v6: Add header dependencies to rcustring.h
> > v5: Rebase against v3.18-rc3
> > v4: Don't return anything from the printk wrappers on the assumption that
> > printk will return void someday
> > v3: Add __rcu annotation to relevant functions, add Paul's ack and Josh's
> > review
> > 
> > Omar Sandoval (3):
> >   Move BTRFS RCU string to common library
> >   btrfs: refactor btrfs_device->name updates
> >   btrfs: fix suspicious RCU in BTRFS_IOC_DEV_INFO
> > 
> >  fs/btrfs/check-integrity.c |   6 +--
> >  fs/btrfs/dev-replace.c     |  19 ++++----
> >  fs/btrfs/disk-io.c         |   6 +--
> >  fs/btrfs/extent_io.c       |   4 +-
> >  fs/btrfs/ioctl.c           |  14 +++---
> >  fs/btrfs/raid56.c          |   2 +-
> >  fs/btrfs/rcu-string.h      |  56 ------------------------
> >  fs/btrfs/scrub.c           |  15 ++++---
> >  fs/btrfs/super.c           |   2 +-
> >  fs/btrfs/volumes.c         | 107 ++++++++++++++++++++++++++++++---------------
> >  fs/btrfs/volumes.h         |   2 +-
> >  include/linux/rcustring.h  |  97 ++++++++++++++++++++++++++++++++++++++++
> >  12 files changed, 204 insertions(+), 126 deletions(-)
> >  delete mode 100644 fs/btrfs/rcu-string.h
> >  create mode 100644 include/linux/rcustring.h
> > 
> > -- 
> > 2.2.1
> > 
> 

Hi, Paul,

I believe Chris is still going to take this one, just wanted to keep you
and the RCU reviewers in the loop.

Thanks!
-- 
Omar