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 <[email protected]>
Reported-by: Sasha Levin <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra (Intel) <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/memory.c b/mm/memory.c
index 649e7d440bd763fa647d47722abb6471cb75ab79..ca920d1fd314a17c7250d7916bd37403afa96b79 100644 (file)
--- 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);