On Tue, 2016-05-10 at 12:49 -0700, Dan Williams wrote:

On Tue, May 10, 2016 at 9:23 AM, Toshi Kani [off-list ref] wrote:

quoted

blkdev_dax_capable() is similar to bdev_dax_supported(), but needs
to remain as a separate interface for checking dax capability of
a raw block device.

Rename and relocate blkdev_dax_capable() to keep them maintained
consistently, and call bdev_direct_access() for the dax capability
check.

There is no change in the behavior.

 :

quoted

diff --git a/block/ioctl.c b/block/ioctl.c
index 4ff1f92..7eeda07 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c

@@ -4,7 +4,6 @@

 #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>

@@ -407,35 +406,6 @@ static inline int is_unrecognized_ioctl(int ret)

                ret == -ENOIOCTLCMD;
 }

-#ifdef CONFIG_FS_DAX
-bool blkdev_dax_capable(struct block_device *bdev)
-{
-       struct gendisk *disk = bdev->bd_disk;
-
-       if (!disk->fops->direct_access)
-               return false;
-
-       /*
-        * If the partition is not aligned on a page boundary, we can't
-        * do dax I/O to it.
-        */
-       if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512))
-                       || (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;
-}
-#endif

This will collide with my pending change to revert raw block device
dax support, and also with Vishal's DAX error handling changes.  For
coordination purposes I'm thining this should all go on top of the
branch that Vishal is putting together with the dax zeroing changes
from Jan and Christoph as well.

This patch does not depend on the rest of the series, so it can be handled
separately.  There is a minor conflict -- bdev_dax_capable() is put under
bdev_dax_supported() in the same file.  This should be easy to resolve, but
let me know if you need me to merge it up.

Thanks,
-Toshi