Re: [PATCH v2 0/4] quota: add project quota support

[Dmitry Monakhov <dmonakhov@openvz.org>]

On Sat, 9 Aug 2014 00:39:58 +0800, Li Xi <pkuelelixi@gmail.com> wrote:
> Hi all,
> 
> The following patches propose an implementation of project support
> for ext4. A project is an aggregate of unrelated inodes which might
> scatter in different directories. Inodes belongs to a project
> possesses a same identification i.e. 'project ID', just like every
> inode has its user/group indentification. The following patches adds
> project quota as supplement to the former uer/group quota types.
> 
> This project ID of an inode is iherited from its parent direcotry
> and saved as an internal field of ext4 inode.
> 
> This is not the first existed attepmtion to add project quta support
> for ext4. Patches of subtree quota support which was posted by Dmity
> Monakhov in 2012 (http://lwn.net/Articles/506064/) implemented the
> similar feature in a different way. Rather than saving the project
> (or subtree) ID as an internal inode field, those patches manages
> the ID as extented attributes.
> 
> We rebased both patch sets onto the same kernel version and run
> benchmakrs respectively to comparing the peformance difference.
> It is worth noting that patches from Lai Siyao and Niu Yawei
> (quota: remove-dqptr_sem,
> http://article.gmane.org/gmane.comp.file-systems.ext4/44341/)
> improve the performance of quota enforcement significantly, which
> can be seen clearly from following results.
> 
> It is obvious that extended attribute implementation has performance
> impact when creating files. That is why we choose to push the patches
> which use internal inode field to save project ID.
I'll bet a box of "russian caviar" that AlViro will never ever allow 
to place project ID to generic inode. Because it is obviously has no
reason for any other filesystem except xfs/ext4.

BTW. Which quota options you use for performance testing? It looks like
you use non-journaled quota. But this means that you have to fully
recalculate quota in case of power failure. It is reasonable to enable
journaled-quota, but it result in visible journaling overhead.
> 
> Kernel: 3.16.0-rc5
> Server: Dell R620 (2 x E5-2667@3.3GHz, 256GB memory)
> Storage: 10 x 15K SAS disks(RAID10)
> Test tool: mdtest-1.9.3. Mdtest created 800K files in total. Each
> thread created files in unique directory.
> 
> File Creation:
>                      1thr     2thr     4thr     8thr    16thr
> - vanilla
> quota disabled      66094   105781   178968   186647   172536
> quotaon(ug)         60337    99582   157396   171463   162872
> 
> - vanilla + remove-dqptr_sem patches
> quota disabled      65955   112082   185550   181511   171988
> quotaon(ug)         62391   101905   171013   190570   168914
> 
> - prjquota(xattr)
> quota disabled      61396    97580   147852   146423   164895
> quotaon(ug)         57009    93435   140589   135748   153196
> quotaon(ugP)        57500    89419   133604   125291   105127
> 
> - prjquota(xattr) + remove-dqptr_sem patches
> quota disabled      64053   100078   147608   139403   163960
> quotaon(ug)         60754   104726   149231   139053   165990
> quotaon(ugP)        59238    93606   148921   138434   163931
> 
> - prjquota(internal) + remove-dqptr_sem patches
> quota disabled      65826   111828   181486   189227   171241
> quotaon(ug)         65418   107745   173584   180562   173752
> quotaon(ugP)        64669   103890   169176   186426   172192
> 
> 
> File Removal:
>                      1thr     2thr     4thr     8thr    16thr
> - vanilla
> quota disabled     118059   169825   234661   291812   345656
> quotaon(ug)        106675   135834   153532   100437    87489
> 
> - vanilla + remove-dqptr_sem patches
> quota disabled     120374   168437   236818   291754   331141
> quotaon(ug)        110709   161954   238333   293700   329015
> 
> - prjquota(xattr)
> quota disabled     116680   161662   229190   295642   332959
> quotaon(ug)        104783   134359   154950   100516    87923
> quotaon(ugP)       100240   125978   108653    68286    58991
> 
> - prjquota(xattr) + remove-dqptr_sem patches
> quota disabled     116281   168938   233733   286663   344002
> quotaon(ug)        109775   164995   236001   299389   340683
> quotaon(ugP)       113935   162979   236112   300033   356117
> 
> - prjquota(internal) + remove-dqptr_sem patches
> quota disabled     119537   171565   247418   291068   350138
> quotaon(ug)        121756   159580   240778   298012   342437
> quotaon(ugP)       118954   168022   241206   289055   334008
> 
> Changelog:
> * v2 <- v1:
>   - Add ioctl interface for setting/getting project;
>   - Add EXT4_FEATURE_RO_COMPAT_PROJECT;
>   - Add get_projid() method in struct dquot_operations;
>   - Add error check of ext4_inode_projid_set/get().
> 
> v1: http://article.gmane.org/gmane.comp.file-systems.ext4/45153
> 
> Any comments or feedbacks are appreciated.
> 
> Regards,
>                                           - Li Xi
> 
> Li Xi(4):
>  quota: Adds general codes to enforces project quota limites
>  ext4: Adds project ID support for ext4
>  ext4: Adds project quota support for ext4
>  ext4: Adds ioctl interface support for ext4 project
> 
>  Documentation/filesystems/ext4.txt |    4 +
>  fs/ext4/Kconfig                    |   11 --
>  fs/ext4/Makefile                   |    1 -
>  fs/ext4/ext4.h                     |   19 +++-
>  fs/ext4/ialloc.c                   |   16 +--
>  fs/ext4/inode.c                    |   85 +++++++++++++-
>  fs/ext4/ioctl.c                    |  100 ++++++++++++++++
>  fs/ext4/project.c                  |  224 ------------------------------------
>  fs/ext4/project.h                  |   58 ---------
>  fs/ext4/super.c                    |   45 ++++++--
>  fs/ext4/xattr.c                    |    6 -
>  fs/ext4/xattr.h                    |    2 -
>  fs/quota/Kconfig                   |    9 ++
>  fs/quota/dquot.c                   |  120 ++++++++++++++-----
>  fs/quota/quota.c                   |    5 +-
>  fs/quota/quotaio_v2.h              |    4 +-
>  include/linux/fs.h                 |    1 -
>  include/linux/quota.h              |    8 ++
>  include/uapi/linux/xattr.h         |    2 -
>  19 files changed, 345 insertions(+), 375 deletions(-)
> --
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