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Diffstat (limited to 'block/ioctl.c')
-rw-r--r--block/ioctl.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
index 0918aed2d..d8996bbd7 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>
@@ -406,6 +407,35 @@ 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
+
static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
@@ -568,6 +598,9 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
case BLKTRACESETUP:
case BLKTRACETEARDOWN:
return blk_trace_ioctl(bdev, cmd, argp);
+ case BLKDAXGET:
+ return put_int(arg, !!(bdev->bd_inode->i_flags & S_DAX));
+ break;
case IOC_PR_REGISTER:
return blkdev_pr_register(bdev, argp);
case IOC_PR_RESERVE: