diff options
| author |   Matthew Wilcox <willy@infradead.org> | 2018-11-27 13:16:33 -0800 |
|---|---|---|
| committer |   Dan Williams <dan.j.williams@intel.com> | 2018-11-28 11:08:08 -0800 |
| commit | c93db7bb6ef3251e0ea48ade311d3e9942748e1c (patch) | |
| tree | 30fa411a468978153847efb424e709deedc8cb7e /fs | |
| parent | Linux 4.20-rc4 (diff) | |
| download | linux-dev-c93db7bb6ef3251e0ea48ade311d3e9942748e1c.tar.xz linux-dev-c93db7bb6ef3251e0ea48ade311d3e9942748e1c.zip | |
dax: Check page->mapping isn't NULL
If we race with inode destroy, it's possible for page->mapping to be
NULL before we even enter this routine, as well as after having slept
waiting for the dax entry to become unlocked.
Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
Cc: <stable@vger.kernel.org>
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/dax.c | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -365,7 +365,7 @@ bool dax_lock_mapping_entry(struct page *page) struct address_space *mapping = READ_ONCE(page->mapping); locked = false; - if (!dax_mapping(mapping)) + if (!mapping || !dax_mapping(mapping)) break; /* |