Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add fusectl interface to max_background
  fuse: limit user-specified values of max background requests
  fuse: use drop_nlink() instead of direct nlink manipulation
  fuse: document protocol version negotiation
  fuse: make the number of max background requests and congestion threshold tunable

1 files changed, 27 insertions, 2 deletions

diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index cf593bf9fd3..3e2925a34bf 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -30,6 +30,10 @@
  *  - add umask flag to input argument of open, mknod and mkdir
  *  - add notification messages for invalidation of inodes and
  *    directory entries
+ *
+ * 7.13
+ *  - make max number of background requests and congestion threshold
+ *    tunables
  */
 
 #ifndef _LINUX_FUSE_H
@@ -37,11 +41,31 @@
 
 #include <linux/types.h>
 
+/*
+ * Version negotiation:
+ *
+ * Both the kernel and userspace send the version they support in the
+ * INIT request and reply respectively.
+ *
+ * If the major versions match then both shall use the smallest
+ * of the two minor versions for communication.
+ *
+ * If the kernel supports a larger major version, then userspace shall
+ * reply with the major version it supports, ignore the rest of the
+ * INIT message and expect a new INIT message from the kernel with a
+ * matching major version.
+ *
+ * If the library supports a larger major version, then it shall fall
+ * back to the major protocol version sent by the kernel for
+ * communication and reply with that major version (and an arbitrary
+ * supported minor version).
+ */
+
 /** Version number of this interface */
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 12
+#define FUSE_KERNEL_MINOR_VERSION 13
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -427,7 +451,8 @@ struct fuse_init_out {
 	__u32	minor;
 	__u32	max_readahead;
 	__u32	flags;
-	__u32	unused;
+	__u16   max_background;
+	__u16   congestion_threshold;
 	__u32	max_write;
 };