Hi,
Aneesh Kumar K.V wrote:
> you would need http://www.kernel.org/pub/software/devel/sparse/
> to find and fix these warnings.
I have updated ext4 online defrag to fix sparse warnings.
I also changed the construction of ext4 online defrag patches
to compile one-by-one and make them small but there is
no functional change since previous version.
Outline for ext4 online defrag:
Ext4 online defrag has the following three functions.
1.[ no option ] Solving a single file fragmentation
Single file fragmentation is solved by moving file
data to contiguous free blocks.
2.[ -r ] Solving a relevant file fragmentation
Relevant file fragmentation could be solved by moving
the files under the specified directory close together with
the block containing the directory data.
3.[ -f ] Solving a free space fragmentation
If there is no contiguous free blocks in the filesystem,
the other files are moved to make sufficient space to allocate
contiguous blocks for the target file.
Next steps:
1. Rework of defrag functions based on review comments from Mingming.
2. Implement defrag -f mode with FIEMAP ioctl.
3. Remove the limit of target file size (now 128MB) in -f mode.
* Past mail concerning -f mode.
http://marc.info/?l=linux-ext4&m=118239067704899&w=4
Summary of patches:
* These patches are replaced with ext4 online defrag patches
which are already in the ext4 git tree (linux-2.6.26-rc8).
[PATCH 1/8] Exchange the blocks between two inodes
- Exchange the data blocks between the temporary inode and
the original inode.
[PATCH 2/8] Read and write file data with memory page
- Read the file data from the old blocks to the page and
write the file data on the page into the new blocks.
[PATCH 3/8] Allocate new contiguous blocks with mballoc
- Search contiguous free blocks with mutil-block allocation
and allocate them for the temporary inode.
[PATCH 4/8] Main function of ext4 online defrag and ioctl implementation
- Create the temporary inode and do defrag per
defrag_size (defalut 64MB).
[PATCH 5/8] Defragmentation for the relevant files (-r mode)
- Relevant file fragmentation could be solved by moving
the files under the specified directory close together with
the block containing the directory data.
[PATCH 6/8] Check the free space fragmentation (-f mode)
- Check the free space fragmentation in the block group
where target file is located.
[PATCH 7/8] Move victim files for the target file (-f mode)
- Move victim files to make sufficient space and reallocates
the contiguous blocks for the target file.
[PATCH 8/8] Online defrag command
- The defrag command. Usage is as follows:
- Put the multiple files closer together.
# e4defrag -r directory-name
- Defrag for free space fragmentation.
# e4defrag -f file-name
- Defrag for a single file.
# e4defrag file-name
- Defrag for all files on ext4.
# e4defrag device-name
Comments and reviews are welcome.
Regards,
Akira
On Fri, 2008-04-04 at 20:19 +0900, Akira Fujita wrote:
> Hi,
>
> Aneesh Kumar K.V wrote:
> > you would need http://www.kernel.org/pub/software/devel/sparse/
> > to find and fix these warnings.
>
> I have updated ext4 online defrag to fix sparse warnings.
> I also changed the construction of ext4 online defrag patches
> to compile one-by-one and make them small but there is
> no functional change since previous version.
>
Thanks, I have updated the patch queue with v8
> Outline for ext4 online defrag:
> Ext4 online defrag has the following three functions.
>
> 1.[ no option ] Solving a single file fragmentation
> Single file fragmentation is solved by moving file
> data to contiguous free blocks.
>
> 2.[ -r ] Solving a relevant file fragmentation
> Relevant file fragmentation could be solved by moving
> the files under the specified directory close together with
> the block containing the directory data.
>
> 3.[ -f ] Solving a free space fragmentation
> If there is no contiguous free blocks in the filesystem,
> the other files are moved to make sufficient space to allocate
> contiguous blocks for the target file.
>
> Next steps:
> 1. Rework of defrag functions based on review comments from Mingming.
> 2. Implement defrag -f mode with FIEMAP ioctl.
> 3. Remove the limit of target file size (now 128MB) in -f mode.
> * Past mail concerning -f mode.
> http://marc.info/?l=linux-ext4&m=118239067704899&w=4
>
> Summary of patches:
> * These patches are replaced with ext4 online defrag patches
> which are already in the ext4 git tree (linux-2.6.26-rc8).
>
> [PATCH 1/8] Exchange the blocks between two inodes
> - Exchange the data blocks between the temporary inode and
> the original inode.
>
> [PATCH 2/8] Read and write file data with memory page
> - Read the file data from the old blocks to the page and
> write the file data on the page into the new blocks.
>
> [PATCH 3/8] Allocate new contiguous blocks with mballoc
> - Search contiguous free blocks with mutil-block allocation
> and allocate them for the temporary inode.
>
> [PATCH 4/8] Main function of ext4 online defrag and ioctl implementation
> - Create the temporary inode and do defrag per
> defrag_size (defalut 64MB).
>
I am curious about the ordering here. It seems reverse the order of the
first 4 patches make the logic more clear to me, start from patch 4,
then 3, then 2 and last 1? At lease when I read the describtion of the
first patch I was puzzled by a minute what is this coming from
Just share my thoughts.
Mingming
> [PATCH 5/8] Defragmentation for the relevant files (-r mode)
> - Relevant file fragmentation could be solved by moving
> the files under the specified directory close together with
> the block containing the directory data.
>
> [PATCH 6/8] Check the free space fragmentation (-f mode)
> - Check the free space fragmentation in the block group
> where target file is located.
>
> [PATCH 7/8] Move victim files for the target file (-f mode)
> - Move victim files to make sufficient space and reallocates
> the contiguous blocks for the target file.
>
> [PATCH 8/8] Online defrag command
> - The defrag command. Usage is as follows:
> - Put the multiple files closer together.
> # e4defrag -r directory-name
> - Defrag for free space fragmentation.
> # e4defrag -f file-name
> - Defrag for a single file.
> # e4defrag file-name
> - Defrag for all files on ext4.
> # e4defrag device-name
>
> Comments and reviews are welcome.
>
> Regards,
> Akira
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Hello,
Mingming Cao wrote:
>> Summary of patches:
>> * These patches are replaced with ext4 online defrag patches
>> which are already in the ext4 git tree (linux-2.6.26-rc8).
>>
>> [PATCH 1/8] Exchange the blocks between two inodes
>> - Exchange the data blocks between the temporary inode and
>> the original inode.
>>
>> [PATCH 2/8] Read and write file data with memory page
>> - Read the file data from the old blocks to the page and
>> write the file data on the page into the new blocks.
>>
>> [PATCH 3/8] Allocate new contiguous blocks with mballoc
>> - Search contiguous free blocks with mutil-block allocation
>> and allocate them for the temporary inode.
>>
>> [PATCH 4/8] Main function of ext4 online defrag and ioctl implementation
>> - Create the temporary inode and do defrag per
>> defrag_size (defalut 64MB).
>>
>
> I am curious about the ordering here. It seems reverse the order of the
> first 4 patches make the logic more clear to me, start from patch 4,
> then 3, then 2 and last 1? At lease when I read the describtion of the
> first patch I was puzzled by a minute what is this coming from
>
> Just share my thoughts.
>
Ah, as you said, the ordering the patches is confusing.
I'll reconstruct my patches order(4-3-2-1-5-6-7-8) to be clear
in the future release.
Thanks,
Akira