On 3/2/22 9:37 AM, Jeff Layton wrote:
It's possible we'll have less than a page's worth of residual data, that
is stradding the last two pages in the array. That will make it
incorrectly set the last_piece boolean when it shouldn't.
Account for a non-zero cursor->page_offset when advancing.
It's been quite a while I looked at this code, but isn't
cursor->resid supposed to be the number of bytes remaining,
irrespective of the offset?
Have you found this to cause a failure?
-Alex
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
net/ceph/messenger.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index d3bb656308b4..3f8453773cc8 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -894,10 +894,9 @@ static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
return false; /* no more data */
/* Move on to the next page; offset is already at 0 */
-
BUG_ON(cursor->page_index >= cursor->page_count);
cursor->page_index++;
- cursor->last_piece = cursor->resid <= PAGE_SIZE;
+ cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
return true;
}
