mm/cma.c: warn if the CMA area could not be activated

While activating a CMA area we check to make sure that all the PFNs in
the range are inside the same zone.  This is a requirement for
alloc_contig_range() to work.  Any CMA area failing the check is
disabled for good.  This happens silently right now making all future
cma_alloc() allocations failure inevitable.

Here we add an error message stating that the CMA area could not be
activated which makes it easier to explain any future cma_alloc()
failures on it.  While in there, change the bail out goto label from
'err' to 'not_in_zone' which makes more sense.

Link: http://lkml.kernel.org/r/20170605023729.26303-1-khandual@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/cma.c b/mm/cma.c
index 978b4a1441ef7120678e1fc7973b38c8ccf4dd5a..9e45491917895a23f5bcf49ef5d16596cbf93aeb 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -127,7 +127,7 @@ static int __init cma_activate_area(struct cma *cma)
                         * to be in the same zone.
                         */
                        if (page_zone(pfn_to_page(pfn)) != zone)
-                               goto err;
+                               goto not_in_zone;
                }
                init_cma_reserved_pageblock(pfn_to_page(base_pfn));
        } while (--i);
@@ -141,7 +141,8 @@ static int __init cma_activate_area(struct cma *cma)
 
        return 0;
 
-err:
+not_in_zone:
+       pr_err("CMA area %s could not be activated\n", cma->name);
        kfree(cma->bitmap);
        cma->count = 0;
        return -EINVAL;