Re: [RFC 0/5] Ext4: Add support for blocksize < pagesize for dioread_nolock

[Matthew Bobrowski <mbobrowski@mbobrowski.org>]

On Sun, Nov 03, 2019 at 02:16:06PM -0500, Theodore Y. Ts'o wrote:
> On Tue, Oct 29, 2019 at 12:49:24PM +0530, Ritesh Harjani wrote:
> > 
> > So it looks like these failed tests does not seem to be because of this
> > patch series. But these are broken in general for at least 1K blocksize.
> 
> Agreed, I failed to add them to the exclude list for diread_nolock_1k.  
> Thanks for pointing that out!   
> 
> After looking through these patches, it looks good.  So, I've landed
> this series on the ext4 git tree.
> 
> There are some potential conflicts with Matthew's DIO using imap patch
> set.  I tried resolving them in the obvious way (see the tt/mb-dio
> branch[1] on ext4.git), and unfortunately, there is a flaky test
> failure with generic/270 --- 2 times out 30 runs of generic/270, the
> file system is left inconsistent, with problems found in the block
> allocation bitmap.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/log/?h=tt/mb-dio
> 
> I've verified that generic/270 isn't a problem on -rc3, and it's not a
> problem with just your patch series.  So, it's almost certain it's
> because I screwed up the merge.  I applied each of Matthew's patch one
> at a time, and conflict was in changes in ext4_end_io_dio, which is
> dropped in Matthew's patch.  It wasn't obvious though where the
> dioread-nolock-1k change should be applied in Matthew's patch series.
> Could you take a look?  Thanks!!

Hang on a second.

Are we not prematurely merging this series in with master? I thought
that this is something that should've come after the iomap direct I/O
port, no? The use of io_end's within the new direct I/O implementation
are effectively redundant...

/M