Re: [PATCH 2/2] fat (exportfs): reconnect file handles to evicted inodes/dentries

From: OGAWA Hirofumi
Date: Wed Jul 04 2012 - 23:59:03 EST


"Steve Magnani" <steve@xxxxxxxxxxxxxxx> writes:

>> And can you add explanation the test of this? What were tested?
>
> I set up a memory-limited virtual machine with a 2 GB FAT partition
> containing a kernel tree (~770 MB, ~40000 files, 9 levels) and did some
> 'cp -r' and 'ls -lR' operations on it, some overlapping, some not.

Sounds good. It would be useful to add to changelog.

>> Please don't add new lock_super() usage if it is not necessary. Almost
>> all of lock_super() just replaced lock_kernel() usage. It rather should
>> be removed in future. Probably, this should use inode->i_mutex
>> instead.
>
> I will look into this. My concern was freezing the filesystem while we
> walk the on-disk structures. Also I developed this patch against 2.6.35
> (the Bad Old BKL days) and ported it forward to 3.5.

I see.

>> BTW, the above issue is same with all of directory read.
>>
>> And although this is using i_pos, is there no possibility to be passed
>> the detached inode (i.e. open but unlinked inode, i_pos == 0)?
>
> It is possible, that's why I added code to fall back to using logstart.
>
> I may yet rip out the get_name code. The testing I did before posting the
> patch seemed to indicate that it was needed - I saw ESTALE errors without
> get_name support that I did not see with it present. But I've been
> digging into this some more and I think that was just a coincidence;
> probably I just generated more extreme memory pressure when testing
> without get_name. I should know more tomorrow.

Thanks.
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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