Commit d53471ba authored by Amir Goldstein's avatar Amir Goldstein Committed by Christian Brauner
Browse files

splice: remove permission hook from iter_file_splice_write() 



All the callers of ->splice_write(), (e.g. do_splice_direct() and
do_splice()) already check rw_verify_area() for the entire range
and perform all the other checks that are in vfs_write_iter().

Instead of creating another tiny helper for special caller, just
open-code it.

This is needed for fanotify "pre content" events.

Suggested-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231122122715.2561213-6-amir73il@gmail.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent b70d8e2b

fs/splice.c

+10 −3
Original line number Diff line number Diff line
@@ -673,10 +673,13 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, 
		.u.file = out,

	};

	int nbufs = pipe->max_usage;

	struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),

					GFP_KERNEL);

	struct bio_vec *array;

	ssize_t ret;



	if (!out->f_op->write_iter)

		return -EINVAL;



	array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL);

	if (unlikely(!array))

		return -ENOMEM;
@@ -684,6 +687,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, 


	splice_from_pipe_begin(&sd);

	while (sd.total_len) {

		struct kiocb kiocb;

		struct iov_iter from;

		unsigned int head, tail, mask;

		size_t left;
@@ -733,7 +737,10 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, 
		}



		iov_iter_bvec(&from, ITER_SOURCE, array, n, sd.total_len - left);

		ret = vfs_iter_write(out, &from, &sd.pos, 0);

		init_sync_kiocb(&kiocb, out);

		kiocb.ki_pos = sd.pos;

		ret = call_write_iter(out, &kiocb, &from);

		sd.pos = kiocb.ki_pos;

		if (ret <= 0)

			break;