On 03/30/2011 07:58 PM, Arne Jansen wrote:
> Am 10.03.2011 13:28, schrieb Chris Mason:
>> Excerpts from liubo's message of 2011-03-10 03:50:27 -0500:
>>> On 03/07/2011 10:13 AM, liubo wrote:
>>>> btrfs will remove unused block groups after balance.
>>>> When a empty filesystem is balanced, the block group with tag "DATA" may be
>>>> dropped, and after umount and mount again, it will not find "DATA"
>>>> space_info
>>>> and lead to OOPS.
>>>> So we initial the necessary space_infos(DATA, SYSTEM, METADATA) to avoid
>>>> OOPS.
>>>>
>
> this patch breaks mixed block groups. If the space_infos get added
> upfront, later on all mixed block groups will be added to the data
> space_info, leaving the metadata space_info completely empty.
> No mixed space_info will ever get created.
Hi, Arne,
Sorry for the late reply.
> As a fix it might be enough to call btrfs_init_space_info after
> btrfs_read_block_groups, not before, but I haven't tested it.
>
Seems impossible, the original bug just occurs in btrfs_read_block_groups()...
> This was the cause of the BUG reported by Sergei Trofimovich in the
> thread "v2.6.38-6555-ga44f99c: null pointer dereference on -ENOSPC".
>
Thanks for pointing this out.
Anyway, will dig it more.
thanks,
liubo
> -Arne
>
>>> Hi, Chirs,
>>>
>>> These two fixes are for critical problems(one OOPS and one memory leak), so
>>> would
>>> you please take some time to review them and check if they are ready for
>>> the next
>>> git pull?
>>>
>>> Seems that you have been a lot busy these days. ;)
>> Hi Liubo,
>>
>> I'm looking at both of these. There are no more rc's for 2.6.38, only
>> the final release, so the bar is very high for a commit that goes in.
>>
>> -chris
>>
>>> thanks,
>>> liubo
>>>
>>>> Reported-by: Daniel J Blueman <daniel.blue...@gmail.com>
>>>> Signed-off-by: Liu Bo <liubo2...@cn.fujitsu.com>
>>>> ---
>>>> fs/btrfs/ctree.h | 1 +
>>>> fs/btrfs/disk-io.c | 6 ++++++
>>>> fs/btrfs/extent-tree.c | 23 +++++++++++++++++++++++
>>>> 3 files changed, 30 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>>>> index 28188a7..49c50e5 100644
>>>> --- a/fs/btrfs/ctree.h
>>>> +++ b/fs/btrfs/ctree.h
>>>> @@ -2221,6 +2221,7 @@ int btrfs_error_discard_extent(struct btrfs_root
>>>> *root, u64 bytenr,
>>>> u64 num_bytes);
>>>> int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
>>>> struct btrfs_root *root, u64 type);
>>>> +int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
>>>>
>>>> /* ctree.c */
>>>> int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
>>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>>>> index 3e1ea3e..8bcdc62 100644
>>>> --- a/fs/btrfs/disk-io.c
>>>> +++ b/fs/btrfs/disk-io.c
>>>> @@ -1967,6 +1967,12 @@ struct btrfs_root *open_ctree(struct super_block
>>>> *sb,
>>>> fs_info->metadata_alloc_profile = (u64)-1;
>>>> fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
>>>>
>>>> + ret = btrfs_init_space_info(fs_info);
>>>> + if (ret) {
>>>> + printk(KERN_ERR "Failed to initial space info: %d\n", ret);
>>>> + goto fail_block_groups;
>>>> + }
>>>> +
>>>> ret = btrfs_read_block_groups(extent_root);
>>>> if (ret) {
>>>> printk(KERN_ERR "Failed to read block groups: %d\n", ret);
>>>> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
>>>> index 100e409..08525ee 100644
>>>> --- a/fs/btrfs/extent-tree.c
>>>> +++ b/fs/btrfs/extent-tree.c
>>>> @@ -8714,6 +8714,29 @@ out:
>>>> return ret;
>>>> }
>>>>
>>>> +int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
>>>> +{
>>>> + struct btrfs_space_info *space_info;
>>>> + int ret;
>>>> +
>>>> + ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM, 0, 0,
>>>> + &space_info);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA, 0, 0,
>>>> + &space_info);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA, 0, 0,
>>>> + &space_info);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + return ret;
>>>> +}
>>>> +
>>>> int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start,
>>>> u64 end)
>>>> {
>>>> return unpin_extent_range(root, start, end);
>
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