4.17-stable review patch. If anyone has any objections, please let me know.
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From: Waiman Long longman@redhat.com
commit 03eeafdd9ab06a770d42c2b264d50dff7e2f4eee upstream.
It was found that the use of up_read_non_owner() in NFS was causing the following warning when DEBUG_RWSEMS was configured.
DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
Looking into the rwsem.c file, it was discovered that the corresponding down_read_non_owner() function was not setting the owner field properly. This is fixed now, and the warning should be gone.
Fixes: 5149cbac4235 ("locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches") Signed-off-by: Waiman Long longman@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Tested-by: Gavin Schenk g.schenk@eckelmann.de Cc: Davidlohr Bueso dave@stgolabs.net Cc: Dan Williams dan.j.williams@intel.com Cc: Arnd Bergmann arnd@arndb.de Cc: linux-nfs@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1527168398-4291-1-git-send-email-longman@redhat.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/locking/rwsem.c | 1 + 1 file changed, 1 insertion(+)
--- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semap might_sleep();
__down_read(sem); + rwsem_set_reader_owned(sem); }
EXPORT_SYMBOL(down_read_non_owner);