From: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Date: Mon, 22 Dec 2014 19:01:54 +0000 (+0200)
Subject: Revert "mm/memory.c: share the i_mmap_rwsem"
X-Git-Tag: v5.15~16602
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=48ec833b7851438f02164ea846852ce4696f09ad;p=platform%2Fkernel%2Flinux-starfive.git

Revert "mm/memory.c: share the i_mmap_rwsem"

This reverts commit c8475d144abb1e62958cc5ec281d2a9e161c1946.

There are several[1][2] of bug reports which points to this commit as potential
cause[3].

Let's revert it until we figure out what's going on.

[1] https://lkml.org/lkml/2014/11/14/342
[2] https://lkml.org/lkml/2014/12/22/213
[3] https://lkml.org/lkml/2014/12/9/741

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/memory.c b/mm/memory.c
index 649e7d44..ca920d1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2378,12 +2378,12 @@ void unmap_mapping_range(struct address_space *mapping,
 		details.last_index = ULONG_MAX;
 
 
-	i_mmap_lock_read(mapping);
+	i_mmap_lock_write(mapping);
 	if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap)))
 		unmap_mapping_range_tree(&mapping->i_mmap, &details);
 	if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
 		unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
-	i_mmap_unlock_read(mapping);
+	i_mmap_unlock_write(mapping);
 }
 EXPORT_SYMBOL(unmap_mapping_range);