* Make the number of max background requests and congestion

threshold tunable.

diff --git a/ChangeLog b/ChangeLog
index f7f9db2b76f3ca5aac7e8fe98e016332be2e7664..1376e816df92b97f081a1dfa1bc48497a8ae204a 100644 (file)
--- 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 c547ac8ee0088b18e057761de95664737a0a2c70..70304c364a9a75802707b7ba3363cf5afba418be 100644 (file)
--- 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 bd736307daed5ab27a122d272436c0d62839c1ad..6f9b9b5e8b116b3a11a9f5177e39acf7c135c40e 100644 (file)
--- 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 76eaa3f2dc34baec8e1676d69443d932025e5b69..109f92d7ec08c5d837bd8712d73a7f81353e2294 100644 (file)
--- 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"