net/9p: switch p9_fd_read to kernel_write

Instead of playing with the addressing limits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2017-09-01 17:39:18 +02:00 committed by Al Viro
parent b4bf802a5a
commit 670986ec01

View File

@ -422,8 +422,7 @@ static void p9_read_work(struct work_struct *work)
static int p9_fd_write(struct p9_client *client, void *v, int len)
{
int ret;
mm_segment_t oldfs;
ssize_t ret;
struct p9_trans_fd *ts = NULL;
if (client && client->status != Disconnected)
@ -435,12 +434,7 @@ static int p9_fd_write(struct p9_client *client, void *v, int len)
if (!(ts->wr->f_flags & O_NONBLOCK))
p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
oldfs = get_fs();
set_fs(get_ds());
/* The cast to a user pointer is valid due to the set_fs() */
ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
set_fs(oldfs);
ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;