Re: [Fwd: [Bug 9732] New: oops in extent code via ext4_fallocate]

[Eric Sandeen <sandeen@redhat.com>]

Aneesh Kumar K.V wrote:
> On Fri, Jan 11, 2008 at 02:42:00PM -0600, Eric Sandeen wrote:
> 
>> The BUG_ON is:
>>
>>         BUG_ON(*logical < le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len));
>>
>> where these were the values:
>>
>>         logical 8 ee_block 0 ee_len 32776
>>
>> Haven't looked further into it yet.
>>
> 
> Not able to reproduce. Why is it calling ext4_ext_search_left for that
> value of logical ? ext4_ext_get_blocks should have found that the
> logical belong to an already existing extent and return from there. It
> should have returned from
> 
> 2365      if (create == EXT4_CREATE_UNINITIALIZED_EXT)
> 2366               goto out;
> 
> 
> root@qemu-image:/ext4# /root/testfallocate  -f a 0 100

> root@qemu-image:/ext4# /root/truncate  ./a 50

> root@qemu-image:/ext4# /root/testfallocate  -f a 0 100

This isn't exercising extents code at all, all your sizes are all within
the first block.  Try the numbers I have in the bug?

Or more simply,

[root@bear-05 sdb8]# ./testfallocate -f testfile 0 32768
[root@bear-05 sdb8]# ./testfallocate -f testfile 16384 65536

or

[root@bear-05 sdb8]# ./testfallocate -f testfile 0 16384
[root@bear-05 sdb8]# ./testfallocate -f testfile 32768 65536


-Eric