gfs2: Only dereference i->iov when iter_is_iovec(i)

Only dereference i->iov after establishing that i is of type ITER_IOVEC.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2021-11-03 16:07:36 +01:00
parent 78805cbe5d
commit 9642c8c44d

View file

@ -773,8 +773,8 @@ static inline bool should_fault_in_pages(ssize_t ret, struct iov_iter *i,
size_t *prev_count,
size_t *window_size)
{
char __user *p = i->iov[0].iov_base + i->iov_offset;
size_t count = iov_iter_count(i);
char __user *p;
int pages = 1;
if (likely(!count))
@ -787,14 +787,14 @@ static inline bool should_fault_in_pages(ssize_t ret, struct iov_iter *i,
if (*prev_count != count || !*window_size) {
int pages, nr_dirtied;
pages = min_t(int, BIO_MAX_VECS,
DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE));
pages = min_t(int, BIO_MAX_VECS, DIV_ROUND_UP(count, PAGE_SIZE));
nr_dirtied = max(current->nr_dirtied_pause -
current->nr_dirtied, 1);
pages = min(pages, nr_dirtied);
}
*prev_count = count;
p = i->iov[0].iov_base + i->iov_offset;
*window_size = (size_t)PAGE_SIZE * pages - offset_in_page(p);
return true;
}