1 files changed, 30 insertions, 18 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 1afdffdf80db..e08ab4702d97 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -148,6 +148,26 @@ void fuse_release_background(struct fuse_req *req)
         spin_unlock(&fuse_lock);
 }
 
+static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
+{
+        int i;
+        struct fuse_init_out *arg = &req->misc.init_out;
+
+        if (arg->major != FUSE_KERNEL_VERSION)
+                fc->conn_error = 1;
+        else {
+                fc->minor = arg->minor;
+                fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
+        }
+
+        /* After INIT reply is received other requests can go
+           out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
+           up()s on outstanding_sem.  The last up() is done in
+           fuse_putback_request() */
+        for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
+                up(&fc->outstanding_sem);
+}
+
 /*
  * This function is called when a request is finished.  Either a reply
  * has arrived or it was interrupted (and not yet sent) or some error
@@ -172,21 +192,9 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
                 up_read(&fc->sbput_sem);
         }
         wake_up(&req->waitq);
-        if (req->in.h.opcode == FUSE_INIT) {
-                int i;
-
-                if (req->misc.init_in_out.major != FUSE_KERNEL_VERSION)
-                        fc->conn_error = 1;
-
-                fc->minor = req->misc.init_in_out.minor;
-
-                /* After INIT reply is received other requests can go
-                   out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
-                   up()s on outstanding_sem.  The last up() is done in
-                   fuse_putback_request() */
-                for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
-                        up(&fc->outstanding_sem);
-        } else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {
+        if (req->in.h.opcode == FUSE_INIT)
+                process_init_reply(fc, req);
+        else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {
                 /* Special case for failed iget in CREATE */
                 u64 nodeid = req->in.h.nodeid;
                 __fuse_get_request(req);
@@ -359,7 +367,7 @@ void fuse_send_init(struct fuse_conn *fc)
         /* This is called from fuse_read_super() so there's guaranteed
            to be a request available */
         struct fuse_req *req = do_get_request(fc);
-        struct fuse_init_in_out *arg = &req->misc.init_in_out;
+        struct fuse_init_in *arg = &req->misc.init_in;
         arg->major = FUSE_KERNEL_VERSION;
         arg->minor = FUSE_KERNEL_MINOR_VERSION;
         req->in.h.opcode = FUSE_INIT;
@@ -367,8 +375,12 @@ void fuse_send_init(struct fuse_conn *fc)
         req->in.args[0].size = sizeof(*arg);
         req->in.args[0].value = arg;
         req->out.numargs = 1;
-        req->out.args[0].size = sizeof(*arg);
-        req->out.args[0].value = arg;
+        /* Variable length arguement used for backward compatibility
+           with interface version < 7.5.  Rest of init_out is zeroed
+           by do_get_request(), so a short reply is not a problem */
+        req->out.argvar = 1;
+        req->out.args[0].size = sizeof(struct fuse_init_out);
+        req->out.args[0].value = &req->misc.init_out;
         request_send_background(fc, req);
 }