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 1717ae0d086470451919c232449f5b8339d5062c..83c56ce6ad206a9e9af9033bfd028114cb2d1737 100644 (file)
--- 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 2086dac7243ba82e1ce6762e2d1406014566aaaa..6f00b177a4343c9e839b31e631bae71dcc05ffea 100644 (file)
--- 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;