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Commit 04676269 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Sami Tolvanen
Browse files

BACKPORT: vfs: pass type instead of fn to do_{loop,iter}_readv_writev() 



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

Bug: 67506682
Change-Id: I919a90715ed71d6caf02b1333dbfec5e7e3ad52b
(cherry picked from commit 0f78d06ac1e9b470cbd8f913ee1688c8b2c8feb3)
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
parent 7c20af08

fs/read_write.c

+23 −31
Original line number Diff line number Diff line
@@ -23,9 +23,6 @@ 
#include <asm/uaccess.h>

#include <asm/unistd.h>



typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);

typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);



const struct file_operations generic_ro_fops = {

	.llseek		= generic_file_llseek,

	.read_iter	= generic_file_read_iter,
@@ -675,7 +672,7 @@ 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, struct iov_iter *iter,

		loff_t *ppos, iter_fn_t fn, int flags)

		loff_t *ppos, int type, int flags)

{

	struct kiocb kiocb;

	ssize_t ret;
@@ -692,7 +689,10 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, 
		kiocb.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);

	kiocb.ki_pos = *ppos;



	ret = fn(&kiocb, iter);

	if (type == READ)

		ret = filp->f_op->read_iter(&kiocb, iter);

	else

		ret = filp->f_op->write_iter(&kiocb, iter);

	BUG_ON(ret == -EIOCBQUEUED);

	*ppos = kiocb.ki_pos;

	return ret;
@@ -700,7 +700,7 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, 


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

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

		loff_t *ppos, io_fn_t fn, int flags)

		loff_t *ppos, int type, int flags)

{

	ssize_t ret = 0;
@@ -711,7 +711,13 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, 
		struct iovec iovec = iov_iter_iovec(iter);

		ssize_t nr;



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

		if (type == READ) {

			nr = filp->f_op->read(filp, iovec.iov_base,

					      iovec.iov_len, ppos);

		} else {

			nr = filp->f_op->write(filp, iovec.iov_base,

					       iovec.iov_len, ppos);

		}



		if (nr < 0) {

			if (!ret)
@@ -844,8 +850,6 @@ static ssize_t do_readv_writev(int type, struct file *file, 
	struct iovec *iov = iovstack;

	struct iov_iter iter;

	ssize_t ret;

	io_fn_t fn;

	iter_fn_t iter_fn;



	ret = import_iovec(type, uvector, nr_segs,

			   ARRAY_SIZE(iovstack), &iov, &iter);
@@ -859,19 +863,14 @@ static ssize_t do_readv_writev(int type, struct file *file, 
	if (ret < 0)

		goto out;



	if (type == READ) {

		fn = file->f_op->read;

		iter_fn = file->f_op->read_iter;

	} else {

		fn = (io_fn_t)file->f_op->write;

		iter_fn = file->f_op->write_iter;

	if (type != READ)

		file_start_write(file);

	}



	if (iter_fn)

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

	if ((type == READ && file->f_op->read_iter) ||

	    (type == WRITE && file->f_op->write_iter))

		ret = do_iter_readv_writev(file, &iter, pos, type, flags);

	else

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

		ret = do_loop_readv_writev(file, &iter, pos, type, flags);



	if (type != READ)

		file_end_write(file);
@@ -1069,8 +1068,6 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, 
	struct iovec *iov = iovstack;

	struct iov_iter iter;

	ssize_t ret;

	io_fn_t fn;

	iter_fn_t iter_fn;



	ret = compat_import_iovec(type, uvector, nr_segs,

				  UIO_FASTIOV, &iov, &iter);
@@ -1084,19 +1081,14 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, 
	if (ret < 0)

		goto out;



	if (type == READ) {

		fn = file->f_op->read;

		iter_fn = file->f_op->read_iter;

	} else {

		fn = (io_fn_t)file->f_op->write;

		iter_fn = file->f_op->write_iter;

	if (type != READ)

		file_start_write(file);

	}



	if (iter_fn)

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

	if ((type == READ && file->f_op->read_iter) ||

	    (type == WRITE && file->f_op->write_iter))

		ret = do_iter_readv_writev(file, &iter, pos, type, flags);

	else

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

		ret = do_loop_readv_writev(file, &iter, pos, type, flags);



	if (type != READ)

		file_end_write(file);