[Ocfs2-devel] [PATCH 0/9 v6] ocfs2: support append O_DIRECT write

[Junxiao Bi]

Hi Joseph,

Did this version make any performance improvement with v5? I tested v5,
and it didn't improve performance with original buffer write + sync.

Thanks,
Junxiao.

On 01/20/2015 04:01 PM, Joseph Qi wrote:
> Currently in case of append O_DIRECT write (block not allocated yet),
> ocfs2 will fall back to buffered I/O. This has some disadvantages.
> Firstly, it is not the behavior as expected.
> Secondly, it will consume huge page cache, e.g. in mass backup scenario.
> Thirdly, modern filesystems such as ext4 support this feature.
> 
> In this patch set, the direct I/O write doesn't fallback to buffer I/O
> write any more because the allocate blocks are enabled in direct I/O
> now.
> 
> changelog:
> v6 <- v5:
> -- Take Mark's advice to use prefix "dio-" to distinguish dio orphan
>    entry from unlink/rename.
> -- Take Mark's advice to treat this feature as a ro compat feature.
> -- Fix a bug in case of not cluster aligned io, cluster_align should
>    be !zero_len, not !!zero_len.
> -- Fix a bug in case of fallocate with FALLOC_FL_KEEP_SIZE.
> -- Fix the wrong *ppos and written when completing the rest request
>    using buffer io.
> 
> Corresponding ocfs2 tools (mkfs.ocfs2, tunefs.ocfs2, fsck.ocfs2, etc.)
> will be updated later.
> 
> 
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