Add mmap() and munmap() methods to low level API

Currently this is only useful for CUSE.  Also update retrieve_reply()
method.

3 files changed, 83 insertions, 2 deletions

diff --git a/include/cuse_lowlevel.h b/include/cuse_lowlevel.h
index e147fa2..b8824fb 100644
--- a/include/cuse_lowlevel.h
+++ b/include/cuse_lowlevel.h
@@ -63,6 +63,13 @@ struct cuse_lowlevel_ops {
 		       const void *in_buf, size_t in_bufsz, size_t out_bufsz);
 	void (*poll) (fuse_req_t req, struct fuse_file_info *fi,
 		      struct fuse_pollhandle *ph);
+	void (*mmap) (fuse_req_t req, uint64_t addr, size_t length,
+		      int prot, int flags, off_t offset,
+		      struct fuse_file_info *fi);
+	void (*munmap) (fuse_req_t req, uint64_t map_id, size_t length,
+			struct fuse_file_info *fi);
+	void (*retrieve_reply) (fuse_req_t req, void *cookie, uint64_t map_id,
+				off_t offset, struct fuse_bufvec *bufv);
 };
 
 struct fuse_session *cuse_lowlevel_new(struct fuse_args *args,
diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
index eb8c790..039eb1f 100644
--- a/include/fuse_kernel.h
+++ b/include/fuse_kernel.h
@@ -79,6 +79,7 @@
  *
  * 7.18
  *  - add FUSE_IOCTL_DIR flag
+ *  - add FUSE_MMAP and FUSE_MUNMAP
  */
 
 #ifndef _LINUX_FUSE_H
@@ -308,6 +309,8 @@ enum fuse_opcode {
 	FUSE_POLL          = 40,
 	FUSE_NOTIFY_REPLY  = 41,
 	FUSE_BATCH_FORGET  = 42,
+	FUSE_MMAP          = 43,
+	FUSE_MUNMAP        = 44,
 
 	/* CUSE specific operations */
 	CUSE_INIT          = 4096,
@@ -600,6 +603,28 @@ struct fuse_notify_poll_wakeup_out {
 	__u64	kh;
 };
 
+struct fuse_mmap_in {
+	__u64	fh;
+	__u64	addr;
+	__u64	len;
+	__u32	prot;
+	__u32	flags;
+	__u64	offset;
+};
+
+struct fuse_mmap_out {
+	__u64	mapid;		/* Mmap ID, same namespace as Inode ID */
+	__u64	size;		/* Size of memory region */
+	__u64	reserved;
+};
+
+struct fuse_munmap_in {
+	__u64	fh;
+	__u64	mapid;
+	__u64	size;		/* Size of memory region */
+	__u64	reserved;
+};
+
 struct fuse_in_header {
 	__u32	len;
 	__u32	opcode;
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index 51aea39..6435937 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -911,13 +911,19 @@ struct fuse_lowlevel_ops {
 	/**
 	 * Callback function for the retrieve request
 	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *	fuse_reply_none
+	 *
+	 * @param req request handle
 	 * @param cookie user data supplied to fuse_lowlevel_notify_retrieve()
 	 * @param ino the inode number supplied to fuse_lowlevel_notify_retrieve()
 	 * @param offset the offset supplied to fuse_lowlevel_notify_retrieve()
 	 * @param bufv the buffer containing the returned data
 	 */
-	void (*retrieve_reply) (void *cookie, fuse_ino_t ino, off_t offset,
-				struct fuse_bufvec *bufv);
+	void (*retrieve_reply) (fuse_req_t req, void *cookie, fuse_ino_t ino,
+				off_t offset, struct fuse_bufvec *bufv);
 
 	/**
 	 * Forget about multiple inodes
@@ -951,6 +957,37 @@ struct fuse_lowlevel_ops {
 	 */
 	void (*flock) (fuse_req_t req, fuse_ino_t ino,
 		       struct fuse_file_info *fi, int op);
+
+	/**
+	 * Direct mmap (CUSE only for now)
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param addr starting address (in clients address space)
+	 * @param length length of the mapping
+	 * @param prot desired memory protection of the mapping
+	 * @param flags mmap flags
+	 * @param fi file information
+	 *
+	 * Introduced in version 2.9
+	 */
+	void (*mmap) (fuse_req_t req, fuse_ino_t ino, uint64_t addr,
+		      size_t length, int prot, int flags, off_t offset,
+		      struct fuse_file_info *fi);
+
+	/**
+	 * Direct munmap (CUSE only for now)
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param map_id identifies the mapping
+	 * @param length length of the mapping
+	 * @param fi file information
+	 *
+	 * Introduced in version 2.9
+	 */
+	void (*munmap) (fuse_req_t req, fuse_ino_t ino, uint64_t map_id,
+			size_t length, struct fuse_file_info *fi);
 };
 
 /**
@@ -1234,6 +1271,18 @@ int fuse_reply_ioctl_iov(fuse_req_t req, int result, const struct iovec *iov,
  */
 int fuse_reply_poll(fuse_req_t req, unsigned revents);
 
+/**
+ * Reply to an mmap request
+ *
+ * Possible requests:
+ *   mmap
+ *
+ * @param req request handle
+ * @param map_id identifies the mapping
+ * @param length length of the mapping (from zero offset)
+ */
+int fuse_reply_mmap(fuse_req_t req, uint64_t map_id, size_t length);
+
 /* ----------------------------------------------------------- *
  * Notification						       *
  * ----------------------------------------------------------- */