Commit 82a763e6 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: simplify file splice 



generic_file_splice_read() and iter_file_splice_write() will call back into
f_op->iter_read() and f_op->iter_write() respectively.  These already do
the real file lookup and cred override.  So the code in ovl_splice_read()
and ovl_splice_write() is redundant.

In addition the ovl_file_accessed() call in ovl_splice_write() is
incorrect, though probably harmless.

Fix by calling generic_file_splice_read() and iter_file_splice_write()
directly.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 89bdfaf9

fs/overlayfs/file.c

+2 −44
Original line number Diff line number Diff line
@@ -397,48 +397,6 @@ out_unlock: 
	return ret;

}



static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,

			 struct pipe_inode_info *pipe, size_t len,

			 unsigned int flags)

{

	ssize_t ret;

	struct fd real;

	const struct cred *old_cred;



	ret = ovl_real_fdget(in, &real);

	if (ret)

		return ret;



	old_cred = ovl_override_creds(file_inode(in)->i_sb);

	ret = generic_file_splice_read(real.file, ppos, pipe, len, flags);

	revert_creds(old_cred);



	ovl_file_accessed(in);

	fdput(real);

	return ret;

}



static ssize_t

ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,

			  loff_t *ppos, size_t len, unsigned int flags)

{

	struct fd real;

	const struct cred *old_cred;

	ssize_t ret;



	ret = ovl_real_fdget(out, &real);

	if (ret)

		return ret;



	old_cred = ovl_override_creds(file_inode(out)->i_sb);

	ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);

	revert_creds(old_cred);



	ovl_file_accessed(out);

	fdput(real);

	return ret;

}



static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)

{

	struct fd real;
@@ -746,8 +704,8 @@ const struct file_operations ovl_file_operations = { 
#ifdef CONFIG_COMPAT

	.compat_ioctl	= ovl_compat_ioctl,

#endif

	.splice_read    = ovl_splice_read,

	.splice_write   = ovl_splice_write,

	.splice_read    = generic_file_splice_read,

	.splice_write   = iter_file_splice_write,



	.copy_file_range	= ovl_copy_file_range,

	.remap_file_range	= ovl_remap_file_range,

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