libfuse: add copy_file_range() support

Add support for the relatively new copy_file_range() syscall. Backend
filesystems can now implement an efficient way of cloning/duplicating
data ranges within files. See 'man 2 copy_file_range' for more details.

3 files changed, 91 insertions, 0 deletions

diff --git a/lib/fuse.c b/lib/fuse.c
index b88ef1a..946ae2f 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2359,6 +2359,29 @@ int fuse_fs_fallocate(struct fuse_fs *fs, const char *path, int mode,
 		return -ENOSYS;
 }
 
+ssize_t fuse_fs_copy_file_range(struct fuse_fs *fs, const char *path_in,
+				struct fuse_file_info *fi_in, off_t off_in,
+				const char *path_out,
+				struct fuse_file_info *fi_out, off_t off_out,
+				size_t len, int flags)
+{
+	fuse_get_context()->private_data = fs->user_data;
+	if (fs->op.copy_file_range) {
+		if (fs->debug)
+			fprintf(stderr, "copy_file_range from %s:%llu to "
+			                "%s:%llu, length: %llu\n",
+				path_in,
+				(unsigned long long) off_in,
+				path_out,
+				(unsigned long long) off_out,
+				(unsigned long long) len);
+
+		return fs->op.copy_file_range(path_in, fi_in, off_in, path_out,
+					      fi_out, off_out, len, flags);
+	} else
+		return -ENOSYS;
+}
+
 static int is_open(struct fuse *f, fuse_ino_t dir, const char *name)
 {
 	struct node *node;
@@ -4290,6 +4313,45 @@ static void fuse_lib_fallocate(fuse_req_t req, fuse_ino_t ino, int mode,
 	reply_err(req, err);
 }
 
+static void fuse_lib_copy_file_range(fuse_req_t req, fuse_ino_t nodeid_in,
+				     off_t off_in, struct fuse_file_info *fi_in,
+				     fuse_ino_t nodeid_out, off_t off_out,
+				     struct fuse_file_info *fi_out, size_t len,
+				     int flags)
+{
+	struct fuse *f = req_fuse_prepare(req);
+	struct fuse_intr_data d;
+	char *path_in, *path_out;
+	int err;
+	ssize_t res;
+
+	err = get_path_nullok(f, nodeid_in, &path_in);
+	if (err) {
+		reply_err(req, err);
+		return;
+	}
+
+	err = get_path_nullok(f, nodeid_out, &path_out);
+	if (err) {
+		free_path(f, nodeid_in, path_in);
+		reply_err(req, err);
+		return;
+	}
+
+	fuse_prepare_interrupt(f, req, &d);
+	res = fuse_fs_copy_file_range(f->fs, path_in, fi_in, off_in, path_out,
+				      fi_out, off_out, len, flags);
+	fuse_finish_interrupt(f, req, &d);
+
+	if (res >= 0)
+		fuse_reply_write(req, res);
+	else
+		reply_err(req, res);
+
+	free_path(f, nodeid_in, path_in);
+	free_path(f, nodeid_out, path_out);
+}
+
 static int clean_delay(struct fuse *f)
 {
 	/*
@@ -4386,6 +4448,7 @@ static struct fuse_lowlevel_ops fuse_path_ops = {
 	.ioctl = fuse_lib_ioctl,
 	.poll = fuse_lib_poll,
 	.fallocate = fuse_lib_fallocate,
+	.copy_file_range = fuse_lib_copy_file_range,
 };
 
 int fuse_notify_poll(struct fuse_pollhandle *ph)
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 844e797..cd59ec0 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1810,6 +1810,27 @@ static void do_fallocate(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		fuse_reply_err(req, ENOSYS);
 }
 
+static void do_copy_file_range(fuse_req_t req, fuse_ino_t nodeid_in, const void *inarg)
+{
+	struct fuse_copy_file_range_in *arg = (struct fuse_copy_file_range_in *) inarg;
+	struct fuse_file_info fi_in, fi_out;
+
+	memset(&fi_in, 0, sizeof(fi_in));
+	fi_in.fh = arg->fh_in;
+
+	memset(&fi_out, 0, sizeof(fi_out));
+	fi_out.fh = arg->fh_out;
+
+
+	if (req->se->op.copy_file_range)
+		req->se->op.copy_file_range(req, nodeid_in, arg->off_in,
+					    &fi_in, arg->nodeid_out,
+					    arg->off_out, &fi_out, arg->len,
+					    arg->flags);
+	else
+		fuse_reply_err(req, ENOSYS);
+}
+
 static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 {
 	struct fuse_init_in *arg = (struct fuse_init_in *) inarg;
@@ -2395,6 +2416,7 @@ static struct {
 	[FUSE_BATCH_FORGET] = { do_batch_forget, "BATCH_FORGET" },
 	[FUSE_READDIRPLUS] = { do_readdirplus,	"READDIRPLUS"},
 	[FUSE_RENAME2]     = { do_rename2,      "RENAME2"    },
+	[FUSE_COPY_FILE_RANGE] = { do_copy_file_range, "COPY_FILE_RANGE" },
 	[CUSE_INIT]	   = { cuse_lowlevel_init, "CUSE_INIT"   },
 };
 
diff --git a/lib/fuse_versionscript b/lib/fuse_versionscript
index 2802bb4..00f955d 100644
--- a/lib/fuse_versionscript
+++ b/lib/fuse_versionscript
@@ -153,6 +153,12 @@ FUSE_3.3 {
 		fuse_open_channel;
 } FUSE_3.2;
 
+FUSE_3.4 {
+	global:
+		fuse_fs_copy_file_range;
+		fuse_reply_copy_file_range;
+} FUSE_3.3;
+
 # Local Variables:
 # indent-tabs-mode: t
 # End: