fs/super.c: sync ro remount after blocking writers

Move sync_filesystem() after sb_prepare_remount_readonly().  If writers
sneak in anywhere from sync_filesystem() to sb_prepare_remount_readonly()
it can cause inodes to be dirtied and writeback to occur well after
sys_mount() has completely successfully.

This was spotted by corrupted ubifs filesystems on reboot, but appears
that it can cause issues with any filesystem using writeback.

CRs-Fixed: 627559
Change-Id: Ib417b59d39210aab2de4e5ae48b18129e8bc3e26
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Richard Weinberger <richard@nod.at>
Co-authored-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Git-commit: 807612db2f9940b9fa6deaef054eb16d51bd3e00
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
msm: kgsl: Add new API's to track device mutex owner

Add new API's kgsl_mutex_lock/unlock to track device mutex owner.
Mutex owner is an atomic variable and all operations set/clear on
it are also atomic to avoid any race conditions.

If a thread tries to acquire the mutex using new API, try to acquire
the mutex only if mutex owner is not same as current thread. This is
to prevent deadlocks which can happen if a thread tries to acquire
mutex with mutex held.

Change-Id: I3da4d0427ede5458f6a663043c57a4799b72d8fd
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
cpufreq: interactive: Optimize sync_freq implementation

Don't let frequency drop below sync_freq if either load or
frequency among other cpus is above a certain threshold,
not necessarily both.

Change-Id: Iada28e08e812498e16d5189b309a7314f88814dd