On Wed, 15 Nov 2006 22:55:43 -0800 Mingming Cao <cmm@xxxxxxxxxx> wrote: > Hmm, maxblocks, in bitmap_search_next_usable_block(), is the end block > number of the range to search, not the lengh of the range. maxblocks > get passed to ext2_find_next_zero_bit(), where it expecting to take the > _size_ of the range to search instead... > > Something like this: (this is not a patch) > @@ -524,7 +524,7 @@ bitmap_search_next_usable_block(ext2_grp > ext2_grpblk_t next; > > - next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start); > + next = ext2_find_next_zero_bit(bh->b_data, maxblocks-start + 1, start); > if (next >= maxblocks) > return -1; > return next; > } yes, the `size' arg to find_next_zero_bit() represents the number of bits to scan at `offset'. So I think your change is correctish. But we don't want the "+ 1", do we? If we're right then this bug could cause the code to scan off the end of the bitmap. But it won't explain Hugh's bug, because of the if (next >= maxblocks). btw, how come try_to_extend_reservation() uses spin_trylock? - 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
