block: enable dax for raw block devices
If an application wants exclusive access to all of the persistent memory
provided by an NVDIMM namespace it can use this raw-block-dax facility
to forgo establishing a filesystem. This capability is targeted
primarily to hypervisors wanting to provision persistent memory for
guests. It can be disabled / enabled dynamically via the new BLKDAXSET
ioctl.
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3aa5142..96fabc9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -482,6 +482,9 @@
int bd_fsfreeze_count;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
+#ifdef CONFIG_FS_DAX
+ int bd_map_count;
+#endif
};
/*
@@ -2264,6 +2267,14 @@
extern void emergency_thaw_all(void);
extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
extern int fsync_bdev(struct block_device *);
+#ifdef CONFIG_FS_DAX
+extern bool blkdev_dax_capable(struct block_device *bdev);
+#else
+static inline bool blkdev_dax_capable(struct block_device *bdev)
+{
+ return false;
+}
+#endif
extern struct super_block *blockdev_superblock;