Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice

To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in fs/fuse when
CONFIG_SYSCALL_SPLICE is undefined.

Signed-off-by: Pieter Smith <redacted>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c

@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
        return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }

-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
                                    struct pipe_inode_info *pipe,
                                    size_t len, unsigned int flags)
 {

@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
        .llseek         = no_llseek,
        .read           = do_sync_read,
        .aio_read       = fuse_dev_read,
-       .splice_read    = fuse_dev_splice_read,
+       .splice_read    = __splice_p(fuse_dev_splice_read),
        .write          = do_sync_write,
        .aio_write      = fuse_dev_write,
        .splice_write   = fuse_dev_splice_write,

diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h

@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
                        int datasync);
 extern void block_sync_page(struct page *page);

+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+