All of lore.kernel.org
 help / color / mirror / Atom feed
From: Brian Foster <bfoster@redhat.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Allison Collins <allison.henderson@oracle.com>,
	linux-xfs@vger.kernel.org
Subject: Re: [PATCH v7 07/19] xfs: Factor out xfs_attr_leaf_addname helper
Date: Tue, 25 Feb 2020 08:26:46 -0500	[thread overview]
Message-ID: <20200225132646.GB21304@bfoster> (raw)
In-Reply-To: <20200225064207.GG10776@dread.disaster.area>

On Tue, Feb 25, 2020 at 05:42:07PM +1100, Dave Chinner wrote:
> On Sat, Feb 22, 2020 at 07:05:59PM -0700, Allison Collins wrote:
> > Factor out new helper function xfs_attr_leaf_try_add. Because new delayed attribute
> > routines cannot roll transactions, we carve off the parts of xfs_attr_leaf_addname
> > that we can use, and move the commit into the calling function.
> 
> 68-72 columns :P
> 
> > 
> > Signed-off-by: Allison Collins <allison.henderson@oracle.com>
> > Reviewed-by: Brian Foster <bfoster@redhat.com>
> > ---
> >  fs/xfs/libxfs/xfs_attr.c | 88 +++++++++++++++++++++++++++++++-----------------
> >  1 file changed, 57 insertions(+), 31 deletions(-)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> > index cf0cba7..b2f0780 100644
> > --- a/fs/xfs/libxfs/xfs_attr.c
> > +++ b/fs/xfs/libxfs/xfs_attr.c
> > @@ -305,10 +305,30 @@ xfs_attr_set_args(
> >  		}
> >  	}
> >  
> > -	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
> > +	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
> >  		error = xfs_attr_leaf_addname(args);
> > -	else
> > -		error = xfs_attr_node_addname(args);
> > +		if (error != -ENOSPC)
> > +			return error;
> > +
> > +		/*
> > +		 * Commit that transaction so that the node_addname()
> > +		 * call can manage its own transactions.
> > +		 */
> > +		error = xfs_defer_finish(&args->trans);
> > +		if (error)
> > +			return error;
> > +
> > +		/*
> > +		 * Commit the current trans (including the inode) and
> > +		 * start a new one.
> > +		 */
> > +		error = xfs_trans_roll_inode(&args->trans, dp);
> > +		if (error)
> > +			return error;
> > +
> > +	}
> > +
> > +	error = xfs_attr_node_addname(args);
> >  	return error;
> 
> 	return xfs_attr_node_addname(args);
> 
> better yet:
> 
> 	if (!xfs_bmap_one_block(dp, XFS_ATTR_FORK))
> 		return xfs_attr_node_addname(args);
> 
> 	error = xfs_attr_leaf_addname(args);
> 	if (error != -ENOSPC)
> 		return error;
> 	.....
> 
> BTW, I think I see the pattern now - isolate all the metadata
> changes from the mechanism of rolling the transactions, which means
> it can be converted to a set of operations connected by a generic
> transaction rolling mechanism. It's all starting to make more sense
> now :P
> 

Yeah.. IIRC the initial attempt at this was going down the path of
creating an entire separate xattr codepath for xattr intents. The
existing codepath has the issue of rolling transactions all over the
place, which makes it difficult to execute from dfops context. The goal
is then to try and take this thing apart such that it works in dfops
context for intents and at the same time can be driven by a high level
transaction rolling loop to support the traditional xattr codepath for
backwards compatibility.

The whole state/context thing fell out of that. I think most agree that
it's ugly, but it's a useful intermediate step for breaking down this
hunk of code into components that can be further evaluated for
simplification and reduction (while making functional progress as well).
E.g., perhaps the top-level states can be eliminated in favor of simply
looking at current xattr fork format. This gets hairier deeper down in
the set path, but I think we may eventually see some similar patterns
emerge when you consider that leaf and node adds follow a very similar
flow and make many of the same function calls with regard to handling
remote values, renames, etc. etc. All in all, I think it will be
interesting if we could come up with some abstractions that ultimately
facilitate removal of the state stuff. That's certainly not clear
enough to me at least right now, but something to keep in mind when
working through this code..

Brian

> > @@ -679,31 +700,36 @@ xfs_attr_leaf_addname(
> >  	retval = xfs_attr3_leaf_add(bp, args);
> >  	if (retval == -ENOSPC) {
> >  		/*
> > -		 * Promote the attribute list to the Btree format, then
> > -		 * Commit that transaction so that the node_addname() call
> > -		 * can manage its own transactions.
> > +		 * Promote the attribute list to the Btree format.
> > +		 * Unless an error occurs, retain the -ENOSPC retval
> >  		 */
> 
> Comments should use all 80 columns...
> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com
> 


  reply	other threads:[~2020-02-25 13:26 UTC|newest]

Thread overview: 135+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-23  2:05 [PATCH v7 00/19] xfs: Delayed Ready Attrs Allison Collins
2020-02-23  2:05 ` [PATCH v7 01/19] xfs: Replace attribute parameters with struct xfs_name Allison Collins
2020-02-23  9:34   ` Amir Goldstein
2020-02-23 16:03     ` Allison Collins
2020-02-25  0:49       ` Dave Chinner
2020-02-24 12:08   ` Chandan Rajendra
2020-02-24 16:25     ` Allison Collins
2020-02-24 13:06   ` Brian Foster
2020-02-24 16:25     ` Allison Collins
2020-02-23  2:05 ` [PATCH v7 02/19] xfs: Embed struct xfs_name in xfs_da_args Allison Collins
2020-02-23 11:54   ` Amir Goldstein
2020-02-23 16:51     ` Allison Collins
2020-02-24  6:50       ` Amir Goldstein
2020-02-24  7:36         ` Allison Collins
2020-02-24  7:43           ` Amir Goldstein
2020-02-25  0:57   ` Dave Chinner
2020-02-25  2:00     ` Allison Collins
2020-02-25  4:06       ` Dave Chinner
2020-02-25  4:19         ` Allison Collins
2020-02-25  4:27           ` Darrick J. Wong
2020-02-25  6:07             ` Allison Collins
2020-02-25  6:30               ` Dave Chinner
2020-02-25 17:21             ` Christoph Hellwig
2020-02-25  6:56   ` Chandan Rajendra
2020-02-25 23:26     ` Allison Collins
2020-02-23  2:05 ` [PATCH v7 03/19] xfs: Add xfs_has_attr and subroutines Allison Collins
2020-02-23 12:20   ` Amir Goldstein
2020-02-23 17:28     ` Allison Collins
2020-02-24  6:58       ` Amir Goldstein
2020-02-25  6:26     ` Dave Chinner
2020-02-25  6:43       ` Amir Goldstein
2020-02-25 22:27         ` Dave Chinner
2020-02-24 13:08   ` Brian Foster
2020-02-24 21:18     ` Allison Collins
2020-02-25 13:25       ` Brian Foster
2020-02-26  2:31         ` Allison Collins
2020-02-25  9:49   ` Chandan Rajendra
2020-02-25 10:15     ` Chandan Rajendra
2020-02-26  2:19       ` Allison Collins
2020-02-26  2:18     ` Allison Collins
2020-02-23  2:05 ` [PATCH v7 04/19] xfs: Check for -ENOATTR or -EEXIST Allison Collins
2020-02-23 12:25   ` Amir Goldstein
2020-02-23 17:33     ` Allison Collins
2020-02-24 13:08   ` Brian Foster
2020-02-24 21:18     ` Allison Collins
2020-02-23  2:05 ` [PATCH v7 05/19] xfs: Factor out new helper functions xfs_attr_rmtval_set Allison Collins
2020-02-25 12:53   ` Chandan Rajendra
2020-02-26  2:20     ` Allison Collins
2020-02-23  2:05 ` [PATCH v7 06/19] xfs: Factor out trans handling in xfs_attr3_leaf_flipflags Allison Collins
2020-02-23 12:30   ` Amir Goldstein
2020-02-23 17:36     ` Allison Collins
2020-02-28  4:56   ` Chandan Rajendra
2020-02-23  2:05 ` [PATCH v7 07/19] xfs: Factor out xfs_attr_leaf_addname helper Allison Collins
2020-02-23 12:42   ` Amir Goldstein
2020-02-23 18:38     ` Allison Collins
2020-02-24  6:38       ` Amir Goldstein
2020-02-24  7:09         ` Allison Collins
2020-02-24  7:27           ` Amir Goldstein
2020-02-25  6:42   ` Dave Chinner
2020-02-25 13:26     ` Brian Foster [this message]
2020-02-25 23:26     ` Allison Collins
2020-02-28  6:51   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 08/19] xfs: Refactor xfs_attr_try_sf_addname Allison Collins
2020-02-23 13:04   ` Amir Goldstein
2020-02-23 17:51     ` Allison Collins
2020-02-24 13:08   ` Brian Foster
2020-02-24 21:19     ` Allison Collins
2020-02-28  7:42   ` Chandan Rajendra
2020-02-28 18:14     ` Allison Collins
2020-02-23  2:06 ` [PATCH v7 09/19] xfs: Factor out trans roll from xfs_attr3_leaf_setflag Allison Collins
2020-02-28  7:59   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 10/19] xfs: Factor out xfs_attr_rmtval_invalidate Allison Collins
2020-02-28 10:42   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 11/19] xfs: Factor out trans roll in xfs_attr3_leaf_clearflag Allison Collins
2020-02-28 10:56   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 12/19] xfs: Add helper function xfs_attr_rmtval_unmap Allison Collins
2020-02-24 13:40   ` Brian Foster
2020-02-24 21:44     ` Allison Collins
2020-02-25 13:27       ` Brian Foster
2020-02-26  3:29         ` Allison Collins
2020-02-26 13:47           ` Brian Foster
2020-02-25  7:21   ` Dave Chinner
2020-02-25 23:27     ` Allison Collins
2020-02-28 14:22   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 13/19] xfs: Add delay ready attr remove routines Allison Collins
2020-02-24 15:25   ` Brian Foster
2020-02-24 17:03     ` Brian Foster
2020-02-24 23:14     ` Allison Collins
2020-02-24 23:56       ` Darrick J. Wong
2020-02-25 13:34       ` Brian Foster
2020-02-26  5:36         ` Allison Collins
2020-02-26 13:48           ` Brian Foster
2020-02-26 19:23             ` Allison Collins
2020-02-25  8:57   ` Dave Chinner
2020-02-26  0:57     ` Allison Collins
2020-02-26 22:34       ` Dave Chinner
2020-02-27  4:18         ` Allison Collins
2020-03-03  5:03   ` Chandan Rajendra
2020-03-03  5:40     ` Allison Collins
2020-02-23  2:06 ` [PATCH v7 14/19] xfs: Add delay ready attr set routines Allison Collins
2020-03-03 13:41   ` Chandan Rajendra
2020-03-03 17:07     ` Allison Collins
2020-02-23  2:06 ` [PATCH v7 15/19] xfs: Add helper function xfs_attr_node_shrink Allison Collins
2020-02-23 13:22   ` Amir Goldstein
2020-02-23 18:41     ` Allison Collins
2020-02-25  9:05   ` Dave Chinner
2020-02-26  1:48     ` Allison Collins
2020-02-23  2:06 ` [PATCH v7 16/19] xfs: Simplify xfs_attr_set_iter Allison Collins
2020-02-23 13:26   ` Amir Goldstein
2020-02-23 18:42     ` Allison Collins
2020-02-25  9:21   ` Dave Chinner
2020-02-26  2:13     ` Allison Collins
2020-02-26 22:39       ` Dave Chinner
2020-03-04  4:30   ` Chandan Rajendra
2020-03-04 17:04     ` Allison Collins
2020-03-05  3:39       ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 17/19] xfs: Add helper function xfs_attr_leaf_mark_incomplete Allison Collins
2020-02-23 13:47   ` Amir Goldstein
2020-02-23 18:43     ` Allison Collins
2020-02-25  9:31   ` Dave Chinner
2020-02-26  2:17     ` Allison Collins
2020-03-04  4:37   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 18/19] xfs: Add remote block helper functions Allison Collins
2020-02-23 13:45   ` Amir Goldstein
2020-03-04  4:59   ` Chandan Rajendra
2020-02-23  2:06 ` [PATCH v7 19/19] xfs: Remove xfs_attr_rmtval_remove Allison Collins
2020-02-23 13:54   ` Amir Goldstein
2020-02-23 18:50     ` Allison Collins
2020-02-23  7:55 ` [PATCH v7 00/19] xfs: Delayed Ready Attrs Amir Goldstein
2020-02-23 16:02   ` Allison Collins
2020-02-24  6:30     ` Amir Goldstein
2020-02-24 16:23       ` Allison Collins
2020-02-25  5:53         ` Amir Goldstein
2020-02-24  8:31   ` Chandan Rajendra
2020-02-25  9:52   ` Dave Chinner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200225132646.GB21304@bfoster \
    --to=bfoster@redhat.com \
    --cc=allison.henderson@oracle.com \
    --cc=david@fromorbit.com \
    --cc=linux-xfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.