Bill Davidsen wrote:
> the value inside the loop is
> correct (or at least is the same as the original patch).
I agree, this can be shown with:
#include <stdio.h>
int main()
{
unsigned int i, count = 10;
printf ("The original loop:\n");
for (i = count-1; i >= 0; i--) {
printf ("%u, ", i);
if (i == -1) {
printf ("which is wrong.\n");
break;
}
}
printf ("As suggested by Bill:\n");
for (i = count; i--; )
printf ("%u, ", i);
printf ("...After the loop i=%u\n");
printf ("Your suggestion:\n");
i = count;
while (i--)
printf ("%u, ", i);
printf ("...After the loop i=%u\n");
return 0;
}
> Theodore Tso wrote:
>> probably
>> the best way of handling this is to recast it not as a for loop, but
>> as a while loop.
Ok, with me. As also shown this will give the same results:
-----------8<--------------->8-------------
Fix loop, with obvious unsigned wrap
Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
---
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 3e5edc9..0e574d4 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -1188,7 +1188,8 @@ static struct ext3_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
/* Split the existing block in the middle, size-wise */
size = 0;
move = 0;
- for (i = count-1; i >= 0; i--) {
+ i = count;
+ while (i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 63adcb7..b8903d4 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1198,7 +1198,8 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
/* Split the existing block in the middle, size-wise */
size = 0;
move = 0;
- for (i = count-1; i >= 0; i--) {
+ i = count;
+ while (i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
