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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2015-09-08 14:59:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 15:35:28 -0700 |
| commit | 46c043ede4711e8d598b9d63c5616c1fedb0605e (patch) | |
| tree | 8a559930980f59ef24c25b73b91899106f8f0418 /mm | |
| parent | 3fdd1b479dbc03347e98f904f54133a9cef5521f (diff) | |
| download | op-kernel-dev-46c043ede4711e8d598b9d63c5616c1fedb0605e.zip op-kernel-dev-46c043ede4711e8d598b9d63c5616c1fedb0605e.tar.gz | |
mm: take i_mmap_lock in unmap_mapping_range() for DAX
DAX is not so special: we need i_mmap_lock to protect mapping->i_mmap.
__dax_pmd_fault() uses unmap_mapping_range() shoot out zero page from
all mappings. We need to drop i_mmap_lock there to avoid lock deadlock.
Re-aquiring the lock should be fine since we check i_size after the
point.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/mm/memory.c b/mm/memory.c index 320c42e..ce8e983 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2426,17 +2426,10 @@ void unmap_mapping_range(struct address_space *mapping, if (details.last_index < details.first_index) details.last_index = ULONG_MAX; - - /* - * DAX already holds i_mmap_lock to serialise file truncate vs - * page fault and page fault vs page fault. - */ - if (!IS_DAX(mapping->host)) - i_mmap_lock_write(mapping); + i_mmap_lock_write(mapping); if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap))) unmap_mapping_range_tree(&mapping->i_mmap, &details); - if (!IS_DAX(mapping->host)) - i_mmap_unlock_write(mapping); + i_mmap_unlock_write(mapping); } EXPORT_SYMBOL(unmap_mapping_range); |
