From: Miklos Szeredi <miklos@szeredi.hu>
Date: Wed, 23 Jun 2010 08:33:32 +0000 (+0000)
Subject: * Make the number of max background requests and congestion
X-Git-Tag: fuse_2_9_0~111
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8b2a7f59b3d07fb82f7df8fa8efd7ff38700e60d;p=qemu-gpiodev%2Flibfuse.git

* Make the number of max background requests and congestion
threshold tunable.
---

diff --git a/ChangeLog b/ChangeLog
index f7f9db2..1376e81 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-06-23  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Make the number of max background requests and congestion
+	threshold tunable.  New options are "max_background" and
+	"congestion_threshold".  Only effective on linux kernel versions
+	2.6.32 or greater.  Patch by Csaba Henk
+
 2010-06-17  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Add fuse_reply_fd() reply function to the low level interface.
diff --git a/include/fuse_common.h b/include/fuse_common.h
index c547ac8..70304c3 100644
--- a/include/fuse_common.h
+++ b/include/fuse_common.h
@@ -159,10 +159,20 @@ struct fuse_conn_info {
 	 */
 	unsigned want;
 
+	/**
+	 * Maximum number of backgrounded requests
+	 */
+	unsigned max_background;
+
+	/**
+	 * Kernel congestion threshold parameter
+	 */
+	unsigned congestion_threshold;
+
 	/**
 	 * For future use.
 	 */
-	unsigned reserved[25];
+	unsigned reserved[23];
 };
 
 struct fuse_session;
diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
index bd73630..6f9b9b5 100644
--- a/include/fuse_kernel.h
+++ b/include/fuse_kernel.h
@@ -66,6 +66,7 @@
 #define __s64 int64_t
 #define __u32 uint32_t
 #define __s32 int32_t
+#define __u16 uint16_t
 
 /*
  * Version negotiation:
@@ -91,7 +92,7 @@
 #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
@@ -477,7 +478,8 @@ struct fuse_init_out {
 	__u32	minor;
 	__u32	max_readahead;
 	__u32	flags;
-	__u32	unused;
+	__u16   max_background;
+	__u16   congestion_threshold;
 	__u32	max_write;
 };
 
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 76eaa3f..109f92d 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1416,6 +1416,19 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		outarg.flags |= FUSE_DONT_MASK;
 	outarg.max_readahead = f->conn.max_readahead;
 	outarg.max_write = f->conn.max_write;
+	if (f->conn.proto_minor >= 13) {
+		if (f->conn.max_background >= (1 << 16))
+			f->conn.max_background = (1 << 16) - 1;
+		if (f->conn.congestion_threshold > f->conn.max_background)
+			f->conn.congestion_threshold = f->conn.max_background;
+		if (!f->conn.congestion_threshold) {
+			f->conn.congestion_threshold =
+				f->conn.max_background * 3 / 4;
+		}
+
+		outarg.max_background = f->conn.max_background;
+		outarg.congestion_threshold = f->conn.congestion_threshold;
+	}
 
 	if (f->debug) {
 		fprintf(stderr, "   INIT: %u.%u\n", outarg.major, outarg.minor);
@@ -1423,6 +1436,10 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		fprintf(stderr, "   max_readahead=0x%08x\n",
 			outarg.max_readahead);
 		fprintf(stderr, "   max_write=0x%08x\n", outarg.max_write);
+		fprintf(stderr, "   max_background=%i\n",
+			outarg.max_background);
+		fprintf(stderr, "   congestion_threshold=%i\n",
+		        outarg.congestion_threshold);
 	}
 
 	send_reply_ok(req, &outarg, arg->minor < 5 ? 8 : sizeof(outarg));
@@ -1709,6 +1726,9 @@ static struct fuse_opt fuse_ll_opts[] = {
 	{ "allow_root", offsetof(struct fuse_ll, allow_root), 1 },
 	{ "max_write=%u", offsetof(struct fuse_ll, conn.max_write), 0 },
 	{ "max_readahead=%u", offsetof(struct fuse_ll, conn.max_readahead), 0 },
+	{ "max_background=%u", offsetof(struct fuse_ll, conn.max_background), 0 },
+	{ "congestion_threshold=%u",
+	  offsetof(struct fuse_ll, conn.congestion_threshold), 0 },
 	{ "async_read", offsetof(struct fuse_ll, conn.async_read), 1 },
 	{ "sync_read", offsetof(struct fuse_ll, conn.async_read), 0 },
 	{ "atomic_o_trunc", offsetof(struct fuse_ll, atomic_o_trunc), 1},
@@ -1735,6 +1755,8 @@ static void fuse_ll_help(void)
 	fprintf(stderr,
 "    -o max_write=N         set maximum size of write requests\n"
 "    -o max_readahead=N     set maximum readahead\n"
+"    -o max_background=N    set number of maximum background requests\n"
+"    -o congestion_threshold=N  set kernel's congestion threshold\n"
 "    -o async_read          perform reads asynchronously (default)\n"
 "    -o sync_read           perform reads synchronously\n"
 "    -o atomic_o_trunc      enable atomic open+truncate support\n"