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

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

7 files changed, 181 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 6269954..636dddc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-12-06  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Add mmap() and munmap() methods to low level API.  Currently
+	this is only useful for CUSE
+
+	* Update retrieve_reply() method
+
 2011-12-05  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Low level API: lock argument of fuse_reply_lock should have a
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						       *
  * ----------------------------------------------------------- */
diff --git a/lib/cuse_lowlevel.c b/lib/cuse_lowlevel.c
index 402cf4b..7bd289a 100644
--- a/lib/cuse_lowlevel.c
+++ b/lib/cuse_lowlevel.c
@@ -93,6 +93,28 @@ static void cuse_fll_poll(fuse_req_t req, fuse_ino_t ino,
 	req_clop(req)->poll(req, fi, ph);
 }
 
+static void cuse_fll_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)
+{
+	(void)ino;
+	req_clop(req)->mmap(req, addr, length, prot, flags, offset, fi);
+}
+
+static void cuse_fll_munmap(fuse_req_t req, fuse_ino_t ino, uint64_t map_id,
+			    size_t length, struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->munmap(req, map_id, length, fi);
+}
+
+static void cuse_fll_retrieve_reply(fuse_req_t req, void *cookie,
+				    fuse_ino_t ino, off_t offset,
+				    struct fuse_bufvec *bufv)
+{
+	req_clop(req)->retrieve_reply(req, cookie, ino, offset, bufv);
+}
+
 static size_t cuse_pack_info(int argc, const char **argv, char *buf)
 {
 	size_t size = 0;
@@ -169,6 +191,10 @@ struct fuse_session *cuse_lowlevel_new(struct fuse_args *args,
 	lop.fsync	= clop->fsync		? cuse_fll_fsync	: NULL;
 	lop.ioctl	= clop->ioctl		? cuse_fll_ioctl	: NULL;
 	lop.poll	= clop->poll		? cuse_fll_poll		: NULL;
+	lop.mmap	= clop->mmap		? cuse_fll_mmap		: NULL;
+	lop.munmap	= clop->munmap		? cuse_fll_munmap	: NULL;
+	lop.retrieve_reply = clop->retrieve_reply ?
+		cuse_fll_retrieve_reply : NULL;
 
 	se = fuse_lowlevel_new_common(args, &lop, sizeof(lop), userdata);
 	if (!se) {
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 8012d49..f69b2b1 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -437,7 +437,18 @@ static int fuse_send_data_iov_fallback(struct fuse_ll *f, struct fuse_chan *ch,
 	void *mbuf;
 	int res;
 
-	/* FIXME: Avoid memory copy if none of the buffers contain an fd */
+	/* Optimize common case */
+	if (buf->count == 1 && buf->idx == 0 && buf->off == 0 &&
+	    !(buf->buf[0].flags & FUSE_BUF_IS_FD)) {
+		/* FIXME: also avoid memory copy if there are multiple buffers
+		   but none of them contain an fd */
+
+		iov[iov_count].iov_base = buf->buf[0].mem;
+		iov[iov_count].iov_len = len;
+		iov_count++;
+		return fuse_send_msg(f, ch, iov, iov_count);
+	}
+
 	res = posix_memalign(&mbuf, pagesize, len);
 	if (res != 0)
 		return res;
@@ -956,6 +967,17 @@ int fuse_reply_poll(fuse_req_t req, unsigned revents)
 	return send_reply_ok(req, &arg, sizeof(arg));
 }
 
+int fuse_reply_mmap(fuse_req_t req, uint64_t map_id, size_t length)
+{
+	struct fuse_mmap_out arg;
+
+	memset(&arg, 0, sizeof(arg));
+	arg.mapid = map_id;
+	arg.size = length;
+
+	return send_reply_ok(req, &arg, sizeof(arg));
+}
+
 static void do_lookup(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 {
 	char *name = (char *) inarg;
@@ -1704,6 +1726,38 @@ static void do_poll(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 	}
 }
 
+static void do_mmap(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
+{
+	struct fuse_mmap_in *arg = (struct fuse_mmap_in *) inarg;
+	struct fuse_file_info fi;
+
+	memset(&fi, 0, sizeof(fi));
+	fi.fh = arg->fh;
+	fi.fh_old = fi.fh;
+
+	if (req->f->op.mmap)
+		req->f->op.mmap(req, nodeid, arg->addr, arg->len, arg->prot,
+				arg->flags, arg->offset, &fi);
+	else
+		fuse_reply_err(req, ENOSYS);
+
+}
+
+static void do_munmap(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
+{
+	struct fuse_munmap_in *arg = (struct fuse_munmap_in *) inarg;
+	struct fuse_file_info fi;
+
+	memset(&fi, 0, sizeof(fi));
+	fi.fh = arg->fh;
+	fi.fh_old = fi.fh;
+
+	if (req->f->op.munmap)
+		req->f->op.munmap(req, nodeid, arg->mapid, arg->size, &fi);
+	else
+		fuse_reply_err(req, ENOSYS);
+}
+
 static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 {
 	struct fuse_init_in *arg = (struct fuse_init_in *) inarg;
@@ -2069,12 +2123,14 @@ static void fuse_ll_retrieve_reply(struct fuse_notify_req *nreq,
 	}
 	bufv.buf[0].size = arg->size;
 
-	if (req->f->op.retrieve_reply)
-		req->f->op.retrieve_reply(rreq->cookie, ino, arg->offset, &bufv);
-	fuse_reply_none(req);
-	free(rreq);
-
+	if (req->f->op.retrieve_reply) {
+		req->f->op.retrieve_reply(req, rreq->cookie, ino,
+					  arg->offset, &bufv);
+	} else {
+		fuse_reply_none(req);
+	}
 out:
+	free(rreq);
 	if ((ibuf->flags & FUSE_BUF_IS_FD) && bufv.idx < bufv.count)
 		fuse_ll_clear_pipe(f);
 }
@@ -2218,6 +2274,8 @@ static struct {
 	[FUSE_DESTROY]	   = { do_destroy,     "DESTROY"     },
 	[FUSE_NOTIFY_REPLY] = { (void *) 1,    "NOTIFY_REPLY" },
 	[FUSE_BATCH_FORGET] = { do_batch_forget, "BATCH_FORGET" },
+	[FUSE_MMAP]        = { do_mmap, "MMAP" },
+	[FUSE_MUNMAP]      = { do_munmap, "MUNMAP" },
 	[CUSE_INIT]	   = { cuse_lowlevel_init, "CUSE_INIT"   },
 };
 
diff --git a/lib/fuse_versionscript b/lib/fuse_versionscript
index 96403c5..1ee1c9d 100644
--- a/lib/fuse_versionscript
+++ b/lib/fuse_versionscript
@@ -194,6 +194,7 @@ FUSE_2.9 {
 		fuse_start_cleanup_thread;
 		fuse_stop_cleanup_thread;
 		fuse_clean_cache;
+		fuse_reply_mmap;
 
 	local:
 		*;