fuse: add support for opening dax device as backing

This is only possible with FUSE_PASSTHROUGH_V2 enabled.

Mark the inode with S_DAX if FUSE_LOOKUP returns with FUSE_ATTR_DAX set.

This patch does not yet provide a way actually use the dax dev backing:
when such a backing ID is provided in reply to FUSE_OPEN with
FOPEN_PASSTHROUGH flag set, an error will be returned.

Truncate and hole punch is not currently allowed on inodes marked with
S_DAX.

Move fuse_backing_put() from fuse_free_inode() to fuse_evict_inode() to
avoid sleeping in atomic context.

Originally-by: John Groves <john@groves.net>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

0 files changed, 0 insertions, 0 deletions