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Commit 88bc7d50 authored by Niels de Vos's avatar Niels de Vos Committed by Miklos Szeredi
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fuse: add support for copy_file_range() 



There are several FUSE filesystems that can implement server-side copy
or other efficient copy/duplication/clone methods. The copy_file_range()
syscall is the standard interface that users have access to while not
depending on external libraries that bypass FUSE.

Signed-off-by: default avatarNiels de Vos <ndevos@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 908a572b

fs/fuse/file.c

+77 −0
Original line number Diff line number Diff line
@@ -3011,6 +3011,82 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, 
	return err;

}



static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in,

				    struct file *file_out, loff_t pos_out,

				    size_t len, unsigned int flags)

{

	struct fuse_file *ff_in = file_in->private_data;

	struct fuse_file *ff_out = file_out->private_data;

	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;

	FUSE_ARGS(args);

	struct fuse_copy_file_range_in inarg = {

		.fh_in = ff_in->fh,

		.off_in = pos_in,

		.nodeid_out = ff_out->nodeid,

		.fh_out = ff_out->fh,

		.off_out = pos_out,

		.len = len,

		.flags = flags

	};

	struct fuse_write_out outarg;

	ssize_t err;

	/* mark unstable when write-back is not used, and file_out gets

	 * extended */

	bool is_unstable = (!fc->writeback_cache) &&

			   ((pos_out + len) > inode_out->i_size);



	if (fc->no_copy_file_range)

		return -EOPNOTSUPP;



	inode_lock(inode_out);



	if (fc->writeback_cache) {

		err = filemap_write_and_wait_range(inode_out->i_mapping,

						   pos_out, pos_out + len);

		if (err)

			goto out;



		fuse_sync_writes(inode_out);

	}



	if (is_unstable)

		set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);



	args.in.h.opcode = FUSE_COPY_FILE_RANGE;

	args.in.h.nodeid = ff_in->nodeid;

	args.in.numargs = 1;

	args.in.args[0].size = sizeof(inarg);

	args.in.args[0].value = &inarg;

	args.out.numargs = 1;

	args.out.args[0].size = sizeof(outarg);

	args.out.args[0].value = &outarg;

	err = fuse_simple_request(fc, &args);

	if (err == -ENOSYS) {

		fc->no_copy_file_range = 1;

		err = -EOPNOTSUPP;

	}

	if (err)

		goto out;



	if (fc->writeback_cache) {

		fuse_write_update_size(inode_out, pos_out + outarg.size);

		file_update_time(file_out);

	}



	fuse_invalidate_attr(inode_out);



	err = outarg.size;

out:

	if (is_unstable)

		clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);



	inode_unlock(inode_out);



	return err;

}



static const struct file_operations fuse_file_operations = {

	.llseek		= fuse_file_llseek,

	.read_iter	= fuse_file_read_iter,
@@ -3027,6 +3103,7 @@ static const struct file_operations fuse_file_operations = { 
	.compat_ioctl	= fuse_file_compat_ioctl,

	.poll		= fuse_file_poll,

	.fallocate	= fuse_file_fallocate,

	.copy_file_range = fuse_copy_file_range,

};



static const struct file_operations fuse_direct_io_file_operations = {

fs/fuse/fuse_i.h

+3 −0
Original line number Diff line number Diff line
@@ -637,6 +637,9 @@ struct fuse_conn { 
	/** Allow other than the mounter user to access the filesystem ? */

	unsigned allow_other:1;



	/** Does the filesystem support copy_file_range? */

	unsigned no_copy_file_range:1;



	/** The number of requests waiting for completion */

	atomic_t num_waiting;

include/uapi/linux/fuse.h

+60 −46
Original line number Diff line number Diff line
@@ -116,6 +116,9 @@ 
 *

 *  7.27

 *  - add FUSE_ABORT_ERROR

 *

 *  7.28

 *  - add FUSE_COPY_FILE_RANGE

 */



#ifndef _LINUX_FUSE_H
@@ -151,7 +154,7 @@ 
#define FUSE_KERNEL_VERSION 7



/** Minor version number of this interface */

#define FUSE_KERNEL_MINOR_VERSION 27

#define FUSE_KERNEL_MINOR_VERSION 28



/** The node ID of the root inode */

#define FUSE_ROOT_ID 1
@@ -381,6 +384,7 @@ enum fuse_opcode { 
	FUSE_READDIRPLUS	= 44,

	FUSE_RENAME2		= 45,

	FUSE_LSEEK		= 46,

	FUSE_COPY_FILE_RANGE	= 47,



	/* CUSE specific operations */

	CUSE_INIT		= 4096,
@@ -792,4 +796,14 @@ struct fuse_lseek_out { 
	uint64_t	offset;

};



struct fuse_copy_file_range_in {

	uint64_t	fh_in;

	uint64_t	off_in;

	uint64_t	nodeid_out;

	uint64_t	fh_out;

	uint64_t	off_out;

	uint64_t	len;

	uint64_t	flags;

};



#endif /* _LINUX_FUSE_H */