[PATCH 1/2] dump: simplify a bit kdump get_next_page()

[marcandre.lureau@redhat.com]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

This should be functionally equivalent, but slightly easier to read,
with simplified paths and checks at the end of the function.

The following patch is a major rewrite to get rid of the assert().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 dump/dump.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/dump/dump.c b/dump/dump.c
index 4d9658ffa2..18f06cffe2 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -1107,37 +1107,31 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
     uint8_t *buf;
 
     /* block == NULL means the start of the iteration */
-    if (!block) {
-        block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
-        *blockptr = block;
-        assert((block->target_start & ~target_page_mask) == 0);
-        assert((block->target_end & ~target_page_mask) == 0);
-        *pfnptr = dump_paddr_to_pfn(s, block->target_start);
-        if (bufptr) {
-            *bufptr = block->host_addr;
-        }
-        return true;
+    if (block == NULL) {
+        *blockptr = block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
+        addr = block->target_start;
+    } else {
+        addr = dump_pfn_to_paddr(s, *pfnptr + 1);
     }
-
-    *pfnptr = *pfnptr + 1;
-    addr = dump_pfn_to_paddr(s, *pfnptr);
+    assert(block != NULL);
 
     if ((addr >= block->target_start) &&
         (addr + s->dump_info.page_size <= block->target_end)) {
         buf = block->host_addr + (addr - block->target_start);
     } else {
         /* the next page is in the next block */
-        block = QTAILQ_NEXT(block, next);
-        *blockptr = block;
+        *blockptr = block = QTAILQ_NEXT(block, next);
         if (!block) {
             return false;
         }
-        assert((block->target_start & ~target_page_mask) == 0);
-        assert((block->target_end & ~target_page_mask) == 0);
-        *pfnptr = dump_paddr_to_pfn(s, block->target_start);
+        addr = block->target_start;
         buf = block->host_addr;
     }
 
+    /* those checks are going away next */
+    assert((block->target_start & ~target_page_mask) == 0);
+    assert((block->target_end & ~target_page_mask) == 0);
+    *pfnptr = dump_paddr_to_pfn(s, addr);
     if (bufptr) {
         *bufptr = buf;
     }
-- 
2.37.2