[PATCH] fuse: add POSIX file locking support

This patch adds POSIX file locking support to the fuse interface.

This implementation doesn't keep any locking state in kernel.  Unlocking on
close() is handled by the FLUSH message, which now contains the lock owner id.

Mandatory locking is not supported.  The filesystem may enfoce mandatory
locking in userspace if needed.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 24 insertions, 2 deletions

diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 8e4319614bef..e7a76ec0f05c 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -1,6 +1,6 @@
 /*
     FUSE: Filesystem in Userspace
-    Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>
+    Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
 
     This program can be distributed under the terms of the GNU GPL.
     See the file COPYING.
@@ -15,7 +15,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 6
+#define FUSE_KERNEL_MINOR_VERSION 7
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -59,6 +59,13 @@ struct fuse_kstatfs {
         __u32   spare[6];
 };
 
+struct fuse_file_lock {
+        __u64   start;
+        __u64   end;
+        __u32   type;
+        __u32   pid; /* tgid */
+};
+
 /**
  * Bitmasks for fuse_setattr_in.valid
  */
@@ -83,6 +90,7 @@ struct fuse_kstatfs {
  * INIT request/reply flags
  */
 #define FUSE_ASYNC_READ         (1 << 0)
+#define FUSE_POSIX_LOCKS        (1 << 1)
 
 enum fuse_opcode {
         FUSE_LOOKUP        = 1,
@@ -113,6 +121,9 @@ enum fuse_opcode {
         FUSE_READDIR       = 28,
         FUSE_RELEASEDIR    = 29,
         FUSE_FSYNCDIR      = 30,
+        FUSE_GETLK         = 31,
+        FUSE_SETLK         = 32,
+        FUSE_SETLKW        = 33,
         FUSE_ACCESS        = 34,
         FUSE_CREATE        = 35
 };
@@ -200,6 +211,7 @@ struct fuse_flush_in {
         __u64   fh;
         __u32   flush_flags;
         __u32   padding;
+        __u64   lock_owner;
 };
 
 struct fuse_read_in {
@@ -248,6 +260,16 @@ struct fuse_getxattr_out {
         __u32   padding;
 };
 
+struct fuse_lk_in {
+        __u64   fh;
+        __u64   owner;
+        struct fuse_file_lock lk;
+};
+
+struct fuse_lk_out {
+        struct fuse_file_lock lk;
+};
+
 struct fuse_access_in {
         __u32   mask;
         __u32   padding;