Ocfs2 devel - Nov 2022 - dinode link count inconsistency in ocfs2_read_links_count() logic

On 11/22/22 12:15 AM, Alexey Asemov (Alex/AT) via Ocfs2-devel
wrote:
> The modification I mentioned surely fixes the thing (well, obviously).
> 
> If to reproduce, trivial as well:
> 
> - mkfs with indexed-dirs option (otherwise low hardlink limit will apply)
> - Create a file
> - Create 65535 hardlinks to it, stat will now show 65536 hardlinks (that
comes from local inode cache)
> - Clear inode cache (for me cat 3 > /proc/sys/vm/drop_caches is enough)
or reboot
> - stat again and you will see hardlink count = 0 that is the result of
actual inconsistency
> 
Will take a deep look into it.

Thanks,
Joseph

Hi,

Checked the code again, since feature indexed dirs is now default on, so
the ocfs2_link_max() check will return OCFS2_DX_LINK_MAX, which can use
high 16 bits of links count.

Could you please send a formal patch?

Thanks,
Joseph

On 11/22/22 9:52 AM, Joseph Qi via Ocfs2-devel wrote:
> 
> 
> On 11/22/22 12:15 AM, Alexey Asemov (Alex/AT) via Ocfs2-devel wrote:
>> The modification I mentioned surely fixes the thing (well, obviously).
>>
>> If to reproduce, trivial as well:
>>
>> - mkfs with indexed-dirs option (otherwise low hardlink limit will
apply)
>> - Create a file
>> - Create 65535 hardlinks to it, stat will now show 65536 hardlinks
(that comes from local inode cache)
>> - Clear inode cache (for me cat 3 > /proc/sys/vm/drop_caches is
enough) or reboot
>> - stat again and you will see hardlink count = 0 that is the result of
actual inconsistency
>>
> 
> Will take a deep look into it.
> 
> Thanks,
> Joseph
> 
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