From: Miklos Szeredi <mszeredi@xxxxxxxxxx>
commit a2bc92362941006830afa3dfad6caec1f99acbf5 upstream.
Prior to sending COPY_FILE_RANGE to userspace filesystem, we must flush all
dirty pages in both the source and destination files.
This patch adds the missing flush of the source file.
Tested on libfuse-3.5.0 with:
libfuse/example/passthrough_ll /mnt/fuse/ -o writeback
libfuse/test/test_syscalls /mnt/fuse/tmp/test
Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/fuse/file.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3098,6 +3098,7 @@ static ssize_t fuse_copy_file_range(stru
{
struct fuse_file *ff_in = file_in->private_data;
struct fuse_file *ff_out = file_out->private_data;
+ struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
struct fuse_inode *fi_out = get_fuse_inode(inode_out);
struct fuse_conn *fc = ff_in->fc;
@@ -3121,6 +3122,17 @@ static ssize_t fuse_copy_file_range(stru
if (fc->no_copy_file_range)
return -EOPNOTSUPP;
+ if (fc->writeback_cache) {
+ inode_lock(inode_in);
+ err = filemap_write_and_wait_range(inode_in->i_mapping,
+ pos_in, pos_in + len);
+ if (!err)
+ fuse_sync_writes(inode_in);
+ inode_unlock(inode_in);
+ if (err)
+ return err;
+ }
+
inode_lock(inode_out);
if (fc->writeback_cache) {
