fs/dax.c: release PMD lock even when there is no PMD support in DAX

follow_pte_pmd() can theoretically return after having acquired a PMD
lock, even when DAX was not compiled with CONFIG_FS_DAX_PMD.

Release the PMD lock unconditionally.

Link: http://lkml.kernel.org/r/20180118133839.20587-1-jschoenh@amazon.de
Fixes: f729c8c9b2 ("dax: wrprotect pmd_t in dax_mapping_entry_mkclean")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan H. Schönherr 2018-01-31 16:14:04 -08:00 committed by Linus Torvalds
parent 7b1cd95d65
commit ee190ca651

View File

@ -636,8 +636,8 @@ static void dax_mapping_entry_mkclean(struct address_space *mapping,
pmd = pmd_mkclean(pmd);
set_pmd_at(vma->vm_mm, address, pmdp, pmd);
unlock_pmd:
spin_unlock(ptl);
#endif
spin_unlock(ptl);
} else {
if (pfn != pte_pfn(*ptep))
goto unlock_pte;