fuse: allow batching of FORGET requests
Terje Malmedal reports that a fuse filesystem with 32 million inodes
on a machine with lots of memory can take up to 30 minutes to process
FORGET requests when all those inodes are evicted from the icache.
To solve this, create a BATCH_FORGET request that allows up to about
8000 FORGET requests to be sent in a single message.
This request is only sent if userspace supports interface version 7.16
or later, otherwise fall back to sending individual FORGET messages.
Reported-by: Terje Malmedal <terje.malmedal@usit.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index c3c578e..cf11881 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -41,6 +41,9 @@
* 7.15
* - add store notify
* - add retrieve notify
+ *
+ * 7.16
+ * - add BATCH_FORGET request
*/
#ifndef _LINUX_FUSE_H
@@ -72,7 +75,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 15
+#define FUSE_KERNEL_MINOR_VERSION 16
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -256,6 +259,7 @@
FUSE_IOCTL = 39,
FUSE_POLL = 40,
FUSE_NOTIFY_REPLY = 41,
+ FUSE_BATCH_FORGET = 42,
/* CUSE specific operations */
CUSE_INIT = 4096,
@@ -290,6 +294,16 @@
__u64 nlookup;
};
+struct fuse_forget_one {
+ __u64 nodeid;
+ __u64 nlookup;
+};
+
+struct fuse_batch_forget_in {
+ __u32 count;
+ __u32 dummy;
+};
+
struct fuse_getattr_in {
__u32 getattr_flags;
__u32 dummy;