From: Miklos Szeredi <mszeredi@redhat.com>
Date: Fri, 14 Feb 2025 10:00:53 +0000 (+0100)
Subject: fuse: optmize missing FUSE_LINK support
X-Git-Tag: v6.15-rc1~51^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eef36cf6a7016cb5353d4b0a9dbdfbd52c4bd973;p=thirdparty%2Fkernel%2Flinux.git

fuse: optmize missing FUSE_LINK support

If filesystem doesn't support FUSE_LINK (i.e. returns -ENOSYS), then
remember this and next time return immediately, without incurring the
overhead of a round trip to the server.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 1717ae0d08647..83c56ce6ad206 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1123,6 +1123,9 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
 	struct fuse_mount *fm = get_fuse_mount(inode);
 	FUSE_ARGS(args);
 
+	if (fm->fc->no_link)
+		goto out;
+
 	memset(&inarg, 0, sizeof(inarg));
 	inarg.oldnodeid = get_node_id(inode);
 	args.opcode = FUSE_LINK;
@@ -1138,7 +1141,11 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
 		fuse_invalidate_attr(inode);
 
 	if (err == -ENOSYS)
-		err = -EPERM;
+		fm->fc->no_link = 1;
+out:
+	if (fm->fc->no_link)
+		return -EPERM;
+
 	return err;
 }
 
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 2086dac7243ba..6f00b177a4343 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -870,6 +870,9 @@ struct fuse_conn {
 	/* Use pages instead of pointer for kernel I/O */
 	unsigned int use_pages_for_kvec_io:1;
 
+	/* Is link not implemented by fs? */
+	unsigned int no_link:1;
+
 	/* Use io_uring for communication */
 	unsigned int io_uring;