Re: [PATCH v11 00/25] xfs: Delay Ready Attributes

Allison Collins
2020-07-25T02:52:30Z

On 7/23/20 10:35 PM, Dave Chinner wrote:
> On Fri, Jul 24, 2020 at 01:41:00PM +1000, Dave Chinner wrote:
>> On Mon, Jul 20, 2020 at 05:15:41PM -0700, Allison Collins wrote:
>>> Hi all,
>>>
>>> This set is a subset of a larger series for delayed attributes. Which is a
>>> subset of an even larger series, parent pointers. Delayed attributes allow
>>> attribute operations (set and remove) to be logged and committed in the same
>>> way that other delayed operations do. This allows more complex operations (like
>>> parent pointers) to be broken up into multiple smaller transactions. To do
>>> this, the existing attr operations must be modified to operate as either a
>>> delayed operation or a inline operation since older filesystems will not be
>>> able to use the new log entries. This means that they cannot roll, commit, or
>>> finish transactions. Instead, they return -EAGAIN to allow the calling
>>> function to handle the transaction. In this series, we focus on only the clean
>>> up and refactoring needed to accomplish this. We will introduce delayed attrs
>>> and parent pointers in a later set.
>>>
>>> At the moment, I would like people to focus their review efforts on just this
>>> "delay ready" subseries, as I think that is a more conservative use of peoples
>>> review time. I also think the set is a bit much to manage all at once, and we
>>> need to get the infrastructure ironed out before we focus too much anything
>>> that depends on it. But I do have the extended series for folks that want to
>>> see the bigger picture of where this is going.
>>>
>>> To help organize the set, I've arranged the patches to make sort of mini sets.
>>> I thought it would help reviewers break down the reviewing some. For reviewing
>>> purposes, the set could be broken up into 4 different phases:
>>>
>>> Error code filtering (patches 1-2):
>>> These two patches are all about finding and catching error codes that need to
>>> be sent back up to user space before starting delayed operations. Errors that
>>> happen during a delayed operation are treated like internal errors that cause a
>>> shutdown. But we wouldnt want that for example: when the user tries to rename
>>> a non existent attr. So the idea is that we need to find all such conditions,
>>> and take care of them before starting a delayed operation.
>>> xfs: Add xfs_has_attr and subroutines
>>> xfs: Check for -ENOATTR or -EEXIST
>>>
>>> Move transactions upwards (patches 3-12):
>>> The goal of this subset is to try and move all the transaction specific code up
>>> the call stack much as possible. The idea being that once we get them to the
>>> top, we can introduce the statemachine to handle the -EAGAIN logic where ever
>>> the transactions used to be.
>>> xfs: Factor out new helper functions xfs_attr_rmtval_set
>>> xfs: Pull up trans handling in xfs_attr3_leaf_flipflags
>>> xfs: Split apart xfs_attr_leaf_addname
>>> xfs: Refactor xfs_attr_try_sf_addname
>>> xfs: Pull up trans roll from xfs_attr3_leaf_setflag
>>> xfs: Factor out xfs_attr_rmtval_invalidate
>>> xfs: Pull up trans roll in xfs_attr3_leaf_clearflag
>>> xfs: Refactor xfs_attr_rmtval_remove
>>> xfs: Pull up xfs_attr_rmtval_invalidate
>>> xfs: Add helper function xfs_attr_node_shrink
>>>
>>> Modularizing and cleanups (patches 13-22):
>>> Now that we have pulled the transactions up to where we need them, it's time to
>>> start breaking down the top level functions into new subfunctions. The goal
>>> being to work towards a top level function that deals mostly with the
>>> statemachine, and helpers for those states
>>> xfs: Remove unneeded xfs_trans_roll_inode calls
>>> xfs: Remove xfs_trans_roll in xfs_attr_node_removename
>>> xfs: Add helpers xfs_attr_is_shortform and xfs_attr_set_shortform
>>> xfs: Add helper function xfs_attr_leaf_mark_incomplete
>>> xfs: Add remote block helper functions
>>> xfs: Add helper function xfs_attr_node_removename_setup
>>> xfs: Add helper function xfs_attr_node_removename_rmt
>>> xfs: Simplify xfs_attr_leaf_addname
>>> xfs: Simplify xfs_attr_node_addname
>>> xfs: Lift -ENOSPC handler from xfs_attr_leaf_addname
>>
>> I'm happy to see everything up to here merged.
>
> BTW, that translates as:
>
> Acked-by: Dave Chinner <dchinner@redhat.com>
>
> For the first 22 patches.
Alrighty, thank you!!

Allison

>
> -Dave.
>