David Sterba wrote on 2015/07/24 14:34 +0200:
On Thu, Jul 23, 2015 at 05:18:10PM +0800, Qu Wenruo wrote:
@@ -246,6 +247,14 @@ static int custom_alloc_extent(struct btrfs_root *root, u64 num_bytes,
continue;
}
+ if (metadata) {
+ BUG_ON(num_bytes != root->nodesize);
This caught my attention and looking at possible values of num_bytes,
this can crash:
1291 for (last_byte = 0; last_byte < first_free; last_byte += sectorsize) {
1292 ret = custom_alloc_extent(root, sectorsize, 0, &key, 0);
where sectorsize == num_bytes.
For that case, the last 0 means that's a data block,
and won't comes to the BUG_ON, as it is only designed for metadata.
And for metadata allocation, the size will only be nodes/leafsize
Thanks,
Qu
+ if (check_crossing_stripes(start, num_bytes)) {
+ last = round_down(start + num_bytes,
+ BTRFS_STRIPE_LEN);
+ continue;
+ }
+ }
clear_extent_dirty(&root->fs_info->free_space_cache,
start, start + num_bytes - 1, 0);
@@ -1280,7 +1289,7 @@ static int create_ext2_image(struct btrfs_root *root, ext2_filsys ext2_fs,
* special, we can't rely on relocate_extents_range to relocate it.
*/
for (last_byte = 0; last_byte < first_free; last_byte += sectorsize) {
- ret = custom_alloc_extent(root, sectorsize, 0, &key);
+ ret = custom_alloc_extent(root, sectorsize, 0, &key, 0);
Same here.
- ret = custom_alloc_extent(root, sectorsize, 0, &key);
+ ret = custom_alloc_extent(root, sectorsize, 0, &key, 0);
And here.
I hope there's a way how to avoid the BUG_ON at all.
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
