libnvdimm, pmem: fix kmap_atomic() leak in error path

When we enounter a bad block we need to kunmap_atomic() before
returning.

Cc: <stable@vger.kernel.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index efc2a5e..e7b86a7 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -66,22 +66,25 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                        unsigned int len, unsigned int off, int rw,
                        sector_t sector)
 {
+       int rc = 0;
        void *mem = kmap_atomic(page);
        phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
        void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
 
        if (rw == READ) {
                if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
-                       return -EIO;
-               memcpy_from_pmem(mem + off, pmem_addr, len);
-               flush_dcache_page(page);
+                       rc = -EIO;
+               else {
+                       memcpy_from_pmem(mem + off, pmem_addr, len);
+                       flush_dcache_page(page);
+               }
        } else {
                flush_dcache_page(page);
                memcpy_to_pmem(pmem_addr, mem + off, len);
        }
 
        kunmap_atomic(mem);
-       return 0;
+       return rc;
 }
 
 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)