fuse: add support for mandatory locking

For mandatory locking the userspace filesystem needs to know the lock
ownership for read, write and truncate operations.

This patch adds the necessary fields to the protocol.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 6f4a31266cd5..7d4fa5b25b87 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -14,6 +14,7 @@
  * 7.9:
  *  - new fuse_getattr_in input argument of GETATTR
  *  - add lk_flags in fuse_lk_in
+ *  - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
  */
 
 #include <asm/types.h>
@@ -86,6 +87,7 @@ struct fuse_file_lock {
 #define FATTR_FH        (1 << 6)
 #define FATTR_ATIME_NOW (1 << 7)
 #define FATTR_MTIME_NOW (1 << 8)
+#define FATTR_LOCKOWNER (1 << 9)
 
 /**
  * Flags returned by the OPEN request
@@ -123,8 +125,15 @@ struct fuse_file_lock {
  * WRITE flags
  *
  * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
+ * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
  */
 #define FUSE_WRITE_CACHE        (1 << 0)
+#define FUSE_WRITE_LOCKOWNER    (1 << 1)
+
+/**
+ * Read flags
+ */
+#define FUSE_READ_LOCKOWNER     (1 << 1)
 
 enum fuse_opcode {
         FUSE_LOOKUP        = 1,
@@ -219,7 +228,7 @@ struct fuse_setattr_in {
         __u32   padding;
         __u64   fh;
         __u64   size;
-        __u64   unused1;
+        __u64   lock_owner;
         __u64   atime;
         __u64   mtime;
         __u64   unused2;
@@ -262,14 +271,18 @@ struct fuse_read_in {
         __u64   fh;
         __u64   offset;
         __u32   size;
-        __u32   padding;
+        __u32   read_flags;
+        __u64   lock_owner;
 };
 
+#define FUSE_COMPAT_WRITE_IN_SIZE 24
+
 struct fuse_write_in {
         __u64   fh;
         __u64   offset;
         __u32   size;
         __u32   write_flags;
+        __u64   lock_owner;
 };
 
 struct fuse_write_out {