Commit 488e8f68 authored by Amir Goldstein's avatar Amir Goldstein Committed by Christian Brauner
Browse files

fs: fork splice_file_range() from do_splice_direct() 



In preparation of calling do_splice_direct() without file_start_write()
held, create a new helper splice_file_range(), to be called from context
of ->copy_file_range() methods instead of do_splice_direct().

Currently, the only difference is that splice_file_range() does not take
flags argument and that it asserts that file_start_write() is held, but
we factor out a common helper do_splice_direct_actor() that will be used
later.

Use the new helper from __ceph_copy_file_range(), that was incorrectly
passing to do_splice_direct() the copy flags argument as splice flags.
The value of copy flags in ceph is always 0, so it is a smenatic bug fix.

Move the declaration of both helpers to linux/splice.h.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231130141624.3338942-2-amir73il@gmail.com


Acked-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 21b32e6a

fs/ceph/file.c

+5 −4
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/falloc.h>

#include <linux/iversion.h>

#include <linux/ktime.h>

#include <linux/splice.h>



#include "super.h"

#include "mds_client.h"
@@ -3010,8 +3011,8 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, 
		 * {read,write}_iter, which will get caps again.

		 */

		put_rd_wr_caps(src_ci, src_got, dst_ci, dst_got);

		ret = do_splice_direct(src_file, &src_off, dst_file,

				       &dst_off, src_objlen, flags);

		ret = splice_file_range(src_file, &src_off, dst_file, &dst_off,

					src_objlen);

		/* Abort on short copies or on error */

		if (ret < (long)src_objlen) {

			doutc(cl, "Failed partial copy (%zd)\n", ret);
@@ -3065,8 +3066,8 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, 
	 */

	if (len && (len < src_ci->i_layout.object_size)) {

		doutc(cl, "Final partial copy of %zu bytes\n", len);

		bytes = do_splice_direct(src_file, &src_off, dst_file,

					 &dst_off, len, flags);

		bytes = splice_file_range(src_file, &src_off, dst_file,

					  &dst_off, len);

		if (bytes > 0)

			ret += bytes;

		else

fs/read_write.c

+2 −4
Original line number Diff line number Diff line
@@ -1423,10 +1423,8 @@ ssize_t generic_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)

{

	lockdep_assert(file_write_started(file_out));



	return do_splice_direct(file_in, &pos_in, file_out, &pos_out,

				len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);

	return splice_file_range(file_in, &pos_in, file_out, &pos_out,

				 min_t(size_t, len, MAX_RW_COUNT));

}

EXPORT_SYMBOL(generic_copy_file_range);

fs/splice.c

+51 −20
Original line number Diff line number Diff line
@@ -1170,25 +1170,10 @@ static void direct_file_splice_eof(struct splice_desc *sd) 
		file->f_op->splice_eof(file);

}



/**

 * do_splice_direct - splices data directly between two files

 * @in:		file to splice from

 * @ppos:	input file offset

 * @out:	file to splice to

 * @opos:	output file offset

 * @len:	number of bytes to splice

 * @flags:	splice modifier flags

 *

 * Description:

 *    For use by do_sendfile(). splice can easily emulate sendfile, but

 *    doing it in the application would incur an extra system call

 *    (splice in + splice out, as compared to just sendfile()). So this helper

 *    can splice directly through a process-private pipe.

 *

 * Callers already called rw_verify_area() on the entire range.

 */

long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,

		      loff_t *opos, size_t len, unsigned int flags)

static long do_splice_direct_actor(struct file *in, loff_t *ppos,

				   struct file *out, loff_t *opos,

				   size_t len, unsigned int flags,

				   splice_direct_actor *actor)

{

	struct splice_desc sd = {

		.len		= len,
@@ -1207,14 +1192,60 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, 
	if (unlikely(out->f_flags & O_APPEND))

		return -EINVAL;



	ret = splice_direct_to_actor(in, &sd, direct_splice_actor);

	ret = splice_direct_to_actor(in, &sd, actor);

	if (ret > 0)

		*ppos = sd.pos;



	return ret;

}

/**

 * do_splice_direct - splices data directly between two files

 * @in:		file to splice from

 * @ppos:	input file offset

 * @out:	file to splice to

 * @opos:	output file offset

 * @len:	number of bytes to splice

 * @flags:	splice modifier flags

 *

 * Description:

 *    For use by do_sendfile(). splice can easily emulate sendfile, but

 *    doing it in the application would incur an extra system call

 *    (splice in + splice out, as compared to just sendfile()). So this helper

 *    can splice directly through a process-private pipe.

 *

 * Callers already called rw_verify_area() on the entire range.

 */

long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,

		      loff_t *opos, size_t len, unsigned int flags)

{

	return do_splice_direct_actor(in, ppos, out, opos, len, flags,

				      direct_splice_actor);

}

EXPORT_SYMBOL(do_splice_direct);



/**

 * splice_file_range - splices data between two files for copy_file_range()

 * @in:		file to splice from

 * @ppos:	input file offset

 * @out:	file to splice to

 * @opos:	output file offset

 * @len:	number of bytes to splice

 *

 * Description:

 *    For use by generic_copy_file_range() and ->copy_file_range() methods.

 *

 * Callers already called rw_verify_area() on the entire range.

 */

long splice_file_range(struct file *in, loff_t *ppos, struct file *out,

		       loff_t *opos, size_t len)

{

	lockdep_assert(file_write_started(out));



	return do_splice_direct_actor(in, ppos, out, opos, len, 0,

				      direct_splice_actor);

}

EXPORT_SYMBOL(splice_file_range);



static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags)

{

	for (;;) {

include/linux/fs.h

+0 −2
Original line number Diff line number Diff line
@@ -3052,8 +3052,6 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos, 
			 size_t len, unsigned int flags);

extern ssize_t iter_file_splice_write(struct pipe_inode_info *,

		struct file *, loff_t *, size_t, unsigned int);

extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,

		loff_t *opos, size_t len, unsigned int flags);





extern void

include/linux/splice.h

+8 −5
Original line number Diff line number Diff line
@@ -80,11 +80,14 @@ extern ssize_t add_to_pipe(struct pipe_inode_info *, 
long vfs_splice_read(struct file *in, loff_t *ppos,

		     struct pipe_inode_info *pipe, size_t len,

		     unsigned int flags);

extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,

				      splice_direct_actor *);

extern long do_splice(struct file *in, loff_t *off_in,

		      struct file *out, loff_t *off_out,

		      size_t len, unsigned int flags);

ssize_t splice_direct_to_actor(struct file *file, struct splice_desc *sd,

			       splice_direct_actor *actor);

long do_splice(struct file *in, loff_t *off_in, struct file *out,

	       loff_t *off_out, size_t len, unsigned int flags);

long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,

		      loff_t *opos, size_t len, unsigned int flags);

long splice_file_range(struct file *in, loff_t *ppos, struct file *out,

		       loff_t *opos, size_t len);



extern long do_tee(struct file *in, struct file *out, size_t len,

		   unsigned int flags);