Unverified Commit f1b4cb65 authored by David Howells's avatar David Howells Committed by Christian Brauner
Browse files

iov_iter: Derive user-backedness from the iterator type 



Use the iterator type to determine whether an iterator is user-backed or
not rather than using a special flag for it.  Now that ITER_UBUF and
ITER_IOVEC are 0 and 1, they can be checked with a single comparison.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20230925120309.1731676-7-dhowells@redhat.com


cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Christian Brauner <christian@brauner.io>
cc: Matthew Wilcox <willy@infradead.org>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: David Laight <David.Laight@ACULAB.COM>
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 7d9e44a6

include/linux/uio.h

+1 −3
Original line number Diff line number Diff line
@@ -43,7 +43,6 @@ struct iov_iter { 
	bool copy_mc;

	bool nofault;

	bool data_source;

	bool user_backed;

	size_t iov_offset;

	/*

	 * Hack alert: overlay ubuf_iovec with iovec + count, so
@@ -140,7 +139,7 @@ static inline unsigned char iov_iter_rw(const struct iov_iter *i) 


static inline bool user_backed_iter(const struct iov_iter *i)

{

	return i->user_backed;

	return iter_is_ubuf(i) || iter_is_iovec(i);

}



/*
@@ -380,7 +379,6 @@ static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction, 
	*i = (struct iov_iter) {

		.iter_type = ITER_UBUF,

		.copy_mc = false,

		.user_backed = true,

		.data_source = direction,

		.ubuf = buf,

		.count = count,

lib/iov_iter.c

+0 −1
Original line number Diff line number Diff line
@@ -290,7 +290,6 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, 
		.iter_type = ITER_IOVEC,

		.copy_mc = false,

		.nofault = false,

		.user_backed = true,

		.data_source = direction,

		.__iov = iov,

		.nr_segs = nr_segs,