4 files changed, 36 insertions, 6 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index a7ef5e716f3c..296351615b00 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -335,9 +335,14 @@ static void fuse_send_readpages(struct fuse_req *req, struct file *file,
         loff_t pos = page_offset(req->pages[0]);
         size_t count = req->num_pages << PAGE_CACHE_SHIFT;
         req->out.page_zeroing = 1;
-        req->end = fuse_readpages_end;
         fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
-        request_send_background(fc, req);
+        if (fc->async_read) {
+                req->end = fuse_readpages_end;
+                request_send_background(fc, req);
+        } else {
+                request_send(fc, req);
+                fuse_readpages_end(fc, req);
+        }
 }
 
 struct fuse_readpages_data {
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 46cf933aa3bf..4a83adfec968 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -272,6 +272,9 @@ struct fuse_conn {
             reply, before any other request, and never cleared */
         unsigned conn_error : 1;
 
+        /** Do readpages asynchronously?  Only set in INIT */
+        unsigned async_read : 1;
+
         /*
          * The following bitfields are only for optimization purposes
          * and hence races in setting them will not cause malfunction
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index c755a0440a66..879e6fba9480 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -473,6 +473,16 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
                 fc->conn_error = 1;
         else {
+                unsigned long ra_pages;
+
+                if (arg->minor >= 6) {
+                        ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
+                        if (arg->flags & FUSE_ASYNC_READ)
+                                fc->async_read = 1;
+                } else
+                        ra_pages = fc->max_read / PAGE_CACHE_SIZE;
+
+                fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
                 fc->minor = arg->minor;
                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
         }
@@ -496,6 +506,8 @@ static void fuse_send_init(struct fuse_conn *fc)
 
         arg->major = FUSE_KERNEL_VERSION;
         arg->minor = FUSE_KERNEL_MINOR_VERSION;
+        arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
+        arg->flags |= FUSE_ASYNC_READ;
         req->in.h.opcode = FUSE_INIT;
         req->in.numargs = 1;
         req->in.args[0].size = sizeof(*arg);
@@ -552,8 +564,6 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
         fc->user_id = d.user_id;
         fc->group_id = d.group_id;
         fc->max_read = d.max_read;
-        if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages)
-                fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 
         /* Used by get_root_inode() */
         sb->s_fs_info = fc;
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 528959c52f1b..5425b60021e3 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -14,7 +14,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 5
+#define FUSE_KERNEL_MINOR_VERSION 6
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -58,6 +58,9 @@ struct fuse_kstatfs {
         __u32   spare[6];
 };
 
+/**
+ * Bitmasks for fuse_setattr_in.valid
+ */
 #define FATTR_MODE      (1 << 0)
 #define FATTR_UID       (1 << 1)
 #define FATTR_GID       (1 << 2)
@@ -75,6 +78,11 @@ struct fuse_kstatfs {
 #define FOPEN_DIRECT_IO         (1 << 0)
 #define FOPEN_KEEP_CACHE        (1 << 1)
 
+/**
+ * INIT request/reply flags
+ */
+#define FUSE_ASYNC_READ         (1 << 0)
+
 enum fuse_opcode {
         FUSE_LOOKUP        = 1,
         FUSE_FORGET        = 2,  /* no reply */
@@ -247,12 +255,16 @@ struct fuse_access_in {
 struct fuse_init_in {
         __u32   major;
         __u32   minor;
+        __u32   max_readahead;
+        __u32   flags;
 };
 
 struct fuse_init_out {
         __u32   major;
         __u32   minor;
-        __u32   unused[3];
+        __u32   max_readahead;
+        __u32   flags;
+        __u32   unused;
         __u32   max_write;
 };