From e4dde731ae70072338352c6f8fb75fd04a42cf8d Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 29 Nov 2010 10:19:07 +0200 Subject: [PATCH] vhost: correctly set bits of dirty pages Fix two bugs in dirty page logging: When counting pages we should increase address by 1 instead of VHOST_PAGE_SIZE. Make log_write() correctly process requests that cross pages with write_address not starting at page boundary. Reported-by: Jason Wang Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 94701ff3a23a..159c77a5746f 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -884,6 +884,7 @@ static int log_write(void __user *log_base, int r; if (!write_length) return 0; + write_length += write_address % VHOST_PAGE_SIZE; write_address /= VHOST_PAGE_SIZE; for (;;) { u64 base = (u64)(unsigned long)log_base; @@ -897,7 +898,7 @@ static int log_write(void __user *log_base, if (write_length <= VHOST_PAGE_SIZE) break; write_length -= VHOST_PAGE_SIZE; - write_address += VHOST_PAGE_SIZE; + write_address += 1; } return r; }