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Commit ac15ac06 authored by Al Viro's avatar Al Viro
Browse files

lift iov_iter into {compat_,}do_readv_writev() 



get it closer to matching {compat_,}rw_copy_check_uvector().

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c0fec3a9

fs/read_write.c

+23 −31
Original line number Diff line number Diff line
@@ -695,25 +695,23 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) 
}

EXPORT_SYMBOL(iov_shorten);



static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iovec *iov,

		unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn)

static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,

		loff_t *ppos, iter_fn_t fn)

{

	struct kiocb kiocb;

	struct iov_iter iter;

	ssize_t ret;



	init_sync_kiocb(&kiocb, filp);

	kiocb.ki_pos = *ppos;



	iov_iter_init(&iter, rw, iov, nr_segs, len);

	ret = fn(&kiocb, &iter);

	ret = fn(&kiocb, iter);

	BUG_ON(ret == -EIOCBQUEUED);

	*ppos = kiocb.ki_pos;

	return ret;

}



static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,

		unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn)

static ssize_t do_sync_readv_writev(struct file *filp, struct iov_iter *iter,

		loff_t *ppos, iov_fn_t fn)

{

	struct kiocb kiocb;

	ssize_t ret;
@@ -721,30 +719,23 @@ static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, 
	init_sync_kiocb(&kiocb, filp);

	kiocb.ki_pos = *ppos;



	ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);

	ret = fn(&kiocb, iter->iov, iter->nr_segs, kiocb.ki_pos);

	BUG_ON(ret == -EIOCBQUEUED);

	*ppos = kiocb.ki_pos;

	return ret;

}



/* Do it by hand, with file-ops */

static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,

		unsigned long nr_segs, loff_t *ppos, io_fn_t fn)

static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,

		loff_t *ppos, io_fn_t fn)

{

	struct iovec *vector = iov;

	ssize_t ret = 0;



	while (nr_segs > 0) {

		void __user *base;

		size_t len;

	while (iov_iter_count(iter)) {

		struct iovec iovec = iov_iter_iovec(iter);

		ssize_t nr;



		base = vector->iov_base;

		len = vector->iov_len;

		vector++;

		nr_segs--;



		nr = fn(filp, base, len, ppos);

		nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);



		if (nr < 0) {

			if (!ret)
@@ -752,8 +743,9 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, 
			break;

		}

		ret += nr;

		if (nr != len)

		if (nr != iovec.iov_len)

			break;

		iov_iter_advance(iter, nr);

	}



	return ret;
@@ -844,6 +836,7 @@ static ssize_t do_readv_writev(int type, struct file *file, 
	size_t tot_len;

	struct iovec iovstack[UIO_FASTIOV];

	struct iovec *iov = iovstack;

	struct iov_iter iter;

	ssize_t ret;

	io_fn_t fn;

	iov_fn_t fnv;
@@ -853,6 +846,7 @@ static ssize_t do_readv_writev(int type, struct file *file, 
				    ARRAY_SIZE(iovstack), iovstack, &iov);

	if (ret <= 0)

		goto out;

	iov_iter_init(&iter, type, iov, nr_segs, ret);



	tot_len = ret;

	ret = rw_verify_area(type, file, pos, tot_len);
@@ -872,13 +866,11 @@ static ssize_t do_readv_writev(int type, struct file *file, 
	}



	if (iter_fn)

		ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len,

						pos, iter_fn);

		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);

	else if (fnv)

		ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,

						pos, fnv);

		ret = do_sync_readv_writev(file, &iter, pos, fnv);

	else

		ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);

		ret = do_loop_readv_writev(file, &iter, pos, fn);



	if (type != READ)

		file_end_write(file);
@@ -1024,6 +1016,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, 
	compat_ssize_t tot_len;

	struct iovec iovstack[UIO_FASTIOV];

	struct iovec *iov = iovstack;

	struct iov_iter iter;

	ssize_t ret;

	io_fn_t fn;

	iov_fn_t fnv;
@@ -1033,6 +1026,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, 
					       UIO_FASTIOV, iovstack, &iov);

	if (ret <= 0)

		goto out;

	iov_iter_init(&iter, type, iov, nr_segs, ret);



	tot_len = ret;

	ret = rw_verify_area(type, file, pos, tot_len);
@@ -1052,13 +1046,11 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, 
	}



	if (iter_fn)

		ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len,

						pos, iter_fn);

		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);

	else if (fnv)

		ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,

						pos, fnv);

		ret = do_sync_readv_writev(file, &iter, pos, fnv);

	else

		ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);

		ret = do_loop_readv_writev(file, &iter, pos, fn);



	if (type != READ)

		file_end_write(file);