[PATCH 2/4] libfuse: add syncfs support to the upper library

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Support syncfs in the upper level library.

Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
 include/fuse.h |    5 +++++
 lib/fuse.c     |   31 +++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)


diff --git a/include/fuse.h b/include/fuse.h
index 6ce6ccfd102386..a59f43e0701e1a 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -890,6 +890,11 @@ struct fuse_operations {
 	 */
 	int (*iomap_config) (uint32_t flags, off_t maxbytes,
 			     struct fuse_iomap_config *cfg);
+
+	/**
+	 * Flush the entire filesystem to disk.
+	 */
+	int (*syncfs) (const char *path);
 #endif /* FUSE_USE_VERSION >= 318 */
 };
 
diff --git a/lib/fuse.c b/lib/fuse.c
index b722a1b526e3de..c3fa6dad589cb0 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2887,6 +2887,16 @@ static int fuse_fs_iomap_config(struct fuse_fs *fs, uint32_t flags,
 	return fs->op.iomap_config(flags, maxbytes, cfg);
 }
 
+static int fuse_fs_syncfs(struct fuse_fs *fs, const char *path)
+{
+	fuse_get_context()->private_data = fs->user_data;
+	if (!fs->op.syncfs)
+		return -ENOSYS;
+	if (fs->debug)
+		fuse_log(FUSE_LOG_DEBUG, "syncfs[%s]\n", path);
+	return fs->op.syncfs(path);
+}
+
 static void fuse_lib_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
 			     int valid, struct fuse_file_info *fi)
 {
@@ -4673,6 +4683,26 @@ static void fuse_lib_iomap_config(fuse_req_t req, uint32_t flags,
 	fuse_reply_iomap_config(req, &cfg);
 }
 
+static void fuse_lib_syncfs(fuse_req_t req, fuse_ino_t ino)
+{
+	struct fuse *f = req_fuse_prepare(req);
+	struct fuse_intr_data d;
+	char *path;
+	int err;
+
+	err = get_path(f, ino, &path);
+	if (err) {
+		reply_err(req, err);
+		return;
+	}
+
+	fuse_prepare_interrupt(f, req, &d);
+	err = fuse_fs_syncfs(f->fs, path);
+	fuse_finish_interrupt(f, req, &d);
+	free_path(f, ino, path);
+	reply_err(req, err);
+}
+
 static int clean_delay(struct fuse *f)
 {
 	/*
@@ -4771,6 +4801,7 @@ static struct fuse_lowlevel_ops fuse_path_ops = {
 	.fallocate = fuse_lib_fallocate,
 	.copy_file_range = fuse_lib_copy_file_range,
 	.lseek = fuse_lib_lseek,
+	.syncfs = fuse_lib_syncfs,
 	.iomap_begin = fuse_lib_iomap_begin,
 	.iomap_end = fuse_lib_iomap_end,
 	.iomap_ioend = fuse_lib_iomap_ioend,