xfs: add xfs_mount sysfs kobject

Embed a base kobject into xfs_mount. This creates a kobject associated
with each XFS mount and a subdirectory in sysfs with the name of the
filesystem. The subdirectory lifecycle matches that of the mount. Also
add the new xfs_sysfs.[c,h] source files with some XFS sysfs
infrastructure to facilitate attribute creation.

Note that there are currently no attributes exported as part of the
xfs_mount kobject. It exists solely to serve as a per-mount container
for child objects.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index f59b966bf903..8312771c2b5b 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -191,6 +191,17 @@ typedef __uint64_t __psunsigned_t;
 #define MAX(a,b)	(max(a,b))
 #define howmany(x, y)	(((x)+((y)-1))/(y))
 
+/*
+ * XFS wrapper structure for sysfs support. It depends on external data
+ * structures and is embedded in various internal data structures to implement
+ * the XFS sysfs object heirarchy. Define it here for broad access throughout
+ * the codebase.
+ */
+struct xfs_kobj {
+	struct kobject		kobject;
+	struct completion	complete;
+};
+
 /* Kernel uid/gid conversion. These are used to convert to/from the on disk
  * uid_t/gid_t types to the kuid_t/kgid_t types that the kernel uses internally.
  * The conversion here is type only, the value will remain the same since we