[libvirt] [PATCH] nodeinfo: fix nodeGetFreePages when max node is zero

[Michal Privoznik]

On 24.09.2014 14:00, Jincheng Miao wrote:
>
> On 09/24/2014 07:40 PM, Michal Privoznik wrote:
>> On 24.09.2014 07:45, Jincheng Miao wrote:
>>> In nodeGetFreePages, if startCell is given by '0',
>>> and the max node number is '0' too. The for-loop
>>> wouldn't be executed.
>>> So convert it to while-loop.
>>>
>>> Before:
>>>> virsh freepages --cellno 0 --pagesize 4
>>> error: internal error: no suitable info found
>>>
>>> After:
>>>> virsh freepages --cellno 0 --pagesize 4
>>> 4KiB: 472637
>>>
>>> Signed-off-by: Jincheng Miao <jmiao at redhat.com>
>>> ---
>>>   src/nodeinfo.c | 7 ++++---
>>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/src/nodeinfo.c b/src/nodeinfo.c
>>> index 2459922..1fe190a 100644
>>> --- a/src/nodeinfo.c
>>> +++ b/src/nodeinfo.c
>>> @@ -2042,18 +2042,19 @@ nodeGetFreePages(unsigned int npages,
>>>       }
>>>
>>>       lastCell = MIN(lastCell, startCell + cellCount);
>>> +    cell = startCell;
>>>
>>> -    for (cell = startCell; cell < lastCell; cell++) {
>>> +    do {
>>>           for (i = 0; i < npages; i++) {
>>>               unsigned int page_size = pages[i];
>>>               unsigned int page_free;
>>>
>>> -            if (virNumaGetPageInfo(cell, page_size, 0, NULL,
>>> &page_free) < 0)
>>> +            if (virNumaGetPageInfo(cell++, page_size, 0, NULL,
>>> &page_free) < 0)
>>>                   goto cleanup;
>>>
>>>               counts[ncounts++] = page_free;
>>>           }
>>> -    }
>>> +    } while (cell < lastCell);
>>>
>>>       if (!ncounts) {
>>>           virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>>>
>>
>> There's no need to switch to do-while loop. All what is needed is cell
>> <= lastCell in the for loop. I'm rewriting the patch and pushing. ACK.
>
> Wait, if change the for condition to 'cell <= lastCell', and pass
> startCell == -1,
> the for-loop will execute twice, and will overwrite counts[1] which is
> not allocated.

Oh, right. Seems like I'm brainwashed today. This is the diff I've 
forgot to 'git add':

diff --git a/src/nodeinfo.c b/src/nodeinfo.c
index 0a7642c..05eab6c 100644
--- a/src/nodeinfo.c
+++ b/src/nodeinfo.c
@@ -2041,7 +2041,7 @@ nodeGetFreePages(unsigned int npages,
          goto cleanup;
      }

-    lastCell = MIN(lastCell, startCell + cellCount);
+    lastCell = MIN(lastCell, startCell + cellCount - 1);

      for (cell = startCell; cell <= lastCell; cell++) {
          for (i = 0; i < npages; i++) {

Michal