Merge commit 'fuse/for-next'

fs/fuse/dev.c

@@ -250,7 +250,7 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 
 static void flush_bg_queue(struct fuse_conn *fc)
 {
-	while (fc->active_background < FUSE_MAX_BACKGROUND &&
+	while (fc->active_background < fc->max_background &&
 	       !list_empty(&fc->bg_queue)) {
 		struct fuse_req *req;
 
@@ -280,11 +280,11 @@ __releases(&fc->lock)
 	list_del(&req->intr_entry);
 	req->state = FUSE_REQ_FINISHED;
 	if (req->background) {
-		if (fc->num_background == FUSE_MAX_BACKGROUND) {
+		if (fc->num_background == fc->max_background) {
 			fc->blocked = 0;
 			wake_up_all(&fc->blocked_waitq);
 		}
-		if (fc->num_background == FUSE_CONGESTION_THRESHOLD &&
+		if (fc->num_background == fc->congestion_threshold &&
 		    fc->connected && fc->bdi_initialized) {
 			clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
 			clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
@@ -410,9 +410,9 @@ static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
 {
 	req->background = 1;
 	fc->num_background++;
-	if (fc->num_background == FUSE_MAX_BACKGROUND)
+	if (fc->num_background == fc->max_background)
 		fc->blocked = 1;
-	if (fc->num_background == FUSE_CONGESTION_THRESHOLD &&
+	if (fc->num_background == fc->congestion_threshold &&
 	    fc->bdi_initialized) {
 		set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
 		set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);

fs/fuse/fuse_i.h

@@ -25,12 +25,6 @@
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
 
-/** Maximum number of outstanding background requests */
-#define FUSE_MAX_BACKGROUND 12
-
-/** Congestion starts at 75% of maximum */
-#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100)
-
 /** Bias for fi->writectr, meaning new writepages must not be sent */
 #define FUSE_NOWRITE INT_MIN
 
@@ -349,6 +343,12 @@ struct fuse_conn {
 	/** rbtree of fuse_files waiting for poll events indexed by ph */
 	struct rb_root polled_files;
 
+	/** Maximum number of outstanding background requests */
+	unsigned max_background;
+
+	/** Number of background requests at which congestion starts */
+	unsigned congestion_threshold;
+
 	/** Number of requests currently in the background */
 	unsigned num_background;
 

fs/fuse/inode.c

@@ -32,6 +32,12 @@ DEFINE_MUTEX(fuse_mutex);
 
 #define FUSE_DEFAULT_BLKSIZE 512
 
+/** Maximum number of outstanding background requests */
+#define FUSE_DEFAULT_MAX_BACKGROUND 12
+
+/** Congestion starts at 75% of maximum */
+#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
+
 struct fuse_mount_data {
 	int fd;
 	unsigned rootmode;
@@ -517,6 +523,8 @@ void fuse_conn_init(struct fuse_conn *fc)
 	INIT_LIST_HEAD(&fc->bg_queue);
 	INIT_LIST_HEAD(&fc->entry);
 	atomic_set(&fc->num_waiting, 0);
+	fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
+	fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 	fc->khctr = 0;
 	fc->polled_files = RB_ROOT;
 	fc->reqctr = 0;
@@ -736,6 +744,12 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 	else {
 		unsigned long ra_pages;
 
+		if (arg->minor >= 13) {
+			if (arg->max_background)
+				fc->max_background = arg->max_background;
+			if (arg->congestion_threshold)
+				fc->congestion_threshold = arg->congestion_threshold;
+		}
 		if (arg->minor >= 6) {
 			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 			if (arg->flags & FUSE_ASYNC_READ)

include/linux/fuse.h

@@ -30,6 +30,10 @@
  *  - add umask flag to input argument of open, mknod and mkdir
  *  - add notification messages for invalidation of inodes and
  *    directory entries
+ *
+ * 7.13
+ *  - make max number of background requests and congestion threshold
+ *    tunables
  */
 
 #ifndef _LINUX_FUSE_H
@@ -37,11 +41,31 @@
 
 #include <linux/types.h>
 
+/*
+ * Version negotiation:
+ *
+ * Both the kernel and userspace send the version they support in the
+ * INIT request and reply respectively.
+ *
+ * If the major versions match then both shall use the smallest
+ * of the two minor versions for communication.
+ *
+ * If the kernel supports a larger major version, then userspace shall
+ * reply with the major version it supports, ignore the rest of the
+ * INIT message and expect a new INIT message from the kernel with a
+ * matching major version.
+ *
+ * If the library supports a larger major version, then it shall fall
+ * back to the major protocol version sent by the kernel for
+ * communication and reply with that major version (and an arbitrary
+ * supported minor version).
+ */
+
 /** Version number of this interface */
 #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
@@ -427,7 +451,8 @@ struct fuse_init_out {
 	__u32	minor;
 	__u32	max_readahead;
 	__u32	flags;
-	__u32	unused;
+	__u16   max_background;
+	__u16   congestion_threshold;
 	__u32	max_write;
 };