fix default_file_splice_read()

Botched calculation of number of pages.  As the result,
we were dropping pieces when doing splice to pipe from
e.g. 9p.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-11-26 20:05:42 -05:00
Родитель 3ad0e83cf8
Коммит 8e54cadab4
1 изменённых файлов: 2 добавлений и 1 удалений

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@ -408,7 +408,8 @@ static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
if (res <= 0)
return -ENOMEM;
nr_pages = res / PAGE_SIZE;
BUG_ON(dummy);
nr_pages = DIV_ROUND_UP(res, PAGE_SIZE);
vec = __vec;
if (nr_pages > PIPE_DEF_BUFFERS) {