pmem, dax: disable dax in the presence of bad blocks
Longer term teach dax to punch "error" holes in mapping requests and
deliver SIGBUS to applications that consume a bad pmem page. For now,
simply disable the dax performance optimization in the presence of known
errors.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/block/ioctl.c b/block/ioctl.c
index 7a964d8..2c84683 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -4,6 +4,7 @@
#include <linux/gfp.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>
+#include <linux/badblocks.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/blktrace_api.h>
@@ -422,6 +423,15 @@
|| (bdev->bd_part->nr_sects % (PAGE_SIZE / 512)))
return false;
+ /*
+ * If the device has known bad blocks, force all I/O through the
+ * driver / page cache.
+ *
+ * TODO: support finer grained dax error handling
+ */
+ if (disk->bb && disk->bb->count)
+ return false;
+
return true;
}