fuse: add file handle to getattr operation

Add necessary protocol changes for supplying a file handle with the getattr
operation.  Step the API version to 7.9.

This patch doesn't actually supply the file handle, because that needs some
kind of VFS support, which we haven't yet been able to agree upon.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fuse/dir.c

@@ -705,10 +705,12 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
 	stat->blksize = (1 << inode->i_blkbits);
 }
 
-static int fuse_do_getattr(struct inode *inode, struct kstat *stat)
+static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
+			   struct file *file)
 {
 	int err;
-	struct fuse_attr_out arg;
+	struct fuse_getattr_in inarg;
+	struct fuse_attr_out outarg;
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
 	u64 attr_version;
@@ -721,24 +723,35 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat)
 	attr_version = fc->attr_version;
 	spin_unlock(&fc->lock);
 
+	memset(&inarg, 0, sizeof(inarg));
+	/* Directories have separate file-handle space */
+	if (file && S_ISREG(inode->i_mode)) {
+		struct fuse_file *ff = file->private_data;
+
+		inarg.getattr_flags |= FUSE_GETATTR_FH;
+		inarg.fh = ff->fh;
+	}
 	req->in.h.opcode = FUSE_GETATTR;
 	req->in.h.nodeid = get_node_id(inode);
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(inarg);
+	req->in.args[0].value = &inarg;
 	req->out.numargs = 1;
-	req->out.args[0].size = sizeof(arg);
-	req->out.args[0].value = &arg;
+	req->out.args[0].size = sizeof(outarg);
+	req->out.args[0].value = &outarg;
 	request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (!err) {
-		if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) {
+		if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
 			make_bad_inode(inode);
 			err = -EIO;
 		} else {
-			fuse_change_attributes(inode, &arg.attr,
-					       attr_timeout(&arg),
+			fuse_change_attributes(inode, &outarg.attr,
+					       attr_timeout(&outarg),
 					       attr_version);
 			if (stat)
-				fuse_fillattr(inode, &arg.attr, stat);
+				fuse_fillattr(inode, &outarg.attr, stat);
 		}
 	}
 	return err;
@@ -833,7 +846,7 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
 	    ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
 		struct fuse_inode *fi = get_fuse_inode(inode);
 		if (fi->i_time < get_jiffies_64()) {
-			err = fuse_do_getattr(inode, NULL);
+			err = fuse_do_getattr(inode, NULL, NULL);
 			if (err)
 				return err;
 
@@ -848,7 +861,7 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
 		   attributes.  This is also needed, because the root
 		   node will at first have no permissions */
 		if (err == -EACCES && !refreshed) {
-			err = fuse_do_getattr(inode, NULL);
+			err = fuse_do_getattr(inode, NULL, NULL);
 			if (!err)
 				err = generic_permission(inode, mask, NULL);
 		}
@@ -864,7 +877,7 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
 			if (refreshed)
 				return -EACCES;
 
-			err = fuse_do_getattr(inode, NULL);
+			err = fuse_do_getattr(inode, NULL, NULL);
 			if (!err && !(inode->i_mode & S_IXUGO))
 				return -EACCES;
 		}
@@ -1107,7 +1120,7 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
 		return -EACCES;
 
 	if (fi->i_time < get_jiffies_64())
-		err = fuse_do_getattr(inode, stat);
+		err = fuse_do_getattr(inode, stat, NULL);
 	else {
 		err = 0;
 		generic_fillattr(inode, stat);

fs/fuse/inode.c

@@ -553,7 +553,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 	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 | FUSE_POSIX_LOCKS;
+	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS;
 	req->in.h.opcode = FUSE_INIT;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(*arg);

include/linux/fuse.h

@@ -6,7 +6,14 @@
     See the file COPYING.
 */
 
-/* This file defines the kernel interface of FUSE */
+/*
+ * This file defines the kernel interface of FUSE
+ *
+ * Protocol changelog:
+ *
+ * 7.9:
+ *  - new fuse_getattr_in input argument of GETATTR
+ */
 
 #include <asm/types.h>
 #include <linux/major.h>
@@ -15,7 +22,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 8
+#define FUSE_KERNEL_MINOR_VERSION 9
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -91,12 +98,18 @@ struct fuse_file_lock {
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
+#define FUSE_FILE_OPS		(1 << 2)
 
 /**
  * Release flags
  */
 #define FUSE_RELEASE_FLUSH	(1 << 0)
 
+/**
+ * Getattr flags
+ */
+#define FUSE_GETATTR_FH		(1 << 0)
+
 enum fuse_opcode {
 	FUSE_LOOKUP	   = 1,
 	FUSE_FORGET	   = 2,  /* no reply */
@@ -154,6 +167,12 @@ struct fuse_forget_in {
 	__u64	nlookup;
 };
 
+struct fuse_getattr_in {
+	__u32	getattr_flags;
+	__u32	dummy;
+	__u64	fh;
+};
+
 struct fuse_attr_out {
 	__u64	attr_valid;	/* Cache timeout for the attributes */
 	__u32	attr_valid_nsec;