public inbox for linux-xfs@vger.kernel.org
 help / color / mirror / Atom feed
From: Brian Foster <bfoster@redhat.com>
To: Allison Collins <allison.henderson@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH v5 13/14] xfs: Add delay ready attr remove routines
Date: Fri, 13 Dec 2019 12:30:46 -0500	[thread overview]
Message-ID: <20191213173046.GG43376@bfoster> (raw)
In-Reply-To: <20191212041513.13855-14-allison.henderson@oracle.com>

On Wed, Dec 11, 2019 at 09:15:12PM -0700, Allison Collins wrote:
> This patch modifies the attr remove routines to be delay ready. This
> means they no longer roll or commit transactions, but instead return
> -EAGAIN to have the calling routine roll and refresh the transaction.
> In this series, xfs_attr_remove_args has become
> xfs_attr_remove_iter, which uses a sort of state machine like switch
> to keep track of where it was when EAGAIN was returned.
> xfs_attr_node_removename has also been modified to use the switch,
> and a  new version of xfs_attr_remove_args consists of a simple loop
> to refresh the transaction until the operation is completed.
> 
> This patch also adds a new struct xfs_delattr_context, which we will
> use to keep track of the current state of an attribute operation.
> The new xfs_delattr_state enum is used to track various operations
> that are in progress so that we know not to repeat them, and resume
> where we left off before EAGAIN was returned to cycle out the
> transaction. Other members take the place of local variables that
> need to retain their values across multiple function recalls.
> 
> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_attr.c     | 127 ++++++++++++++++++++++++++++++++++++-------
>  fs/xfs/libxfs/xfs_attr.h     |   1 +
>  fs/xfs/libxfs/xfs_da_btree.h |  16 ++++++
>  fs/xfs/scrub/common.c        |   2 +
>  fs/xfs/xfs_acl.c             |   2 +
>  fs/xfs/xfs_attr_list.c       |   1 +
>  fs/xfs/xfs_ioctl.c           |   2 +
>  fs/xfs/xfs_ioctl32.c         |   2 +
>  fs/xfs/xfs_iops.c            |   2 +
>  fs/xfs/xfs_xattr.c           |   1 +
>  10 files changed, 137 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index b5a5c84..726b75e 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
...
> @@ -1206,12 +1249,29 @@ xfs_attr_node_removename(
>  	struct xfs_buf		*bp;
>  	int			retval, error, forkoff;
>  	struct xfs_inode	*dp = args->dp;
> +	int			done = 0;
>  
>  	trace_xfs_attr_node_removename(args);
> +	state = args->dac.da_state;
> +	blk = args->dac.blk;
> +
> +	/* State machine switch */
> +	switch (args->dac.dela_state) {
> +	case XFS_DAS_RM_NODE_BLKS:
> +		goto rm_node_blks;
> +	case XFS_DAS_RM_INVALIDATE:
> +		goto rm_invalidate;
> +	case XFS_DAS_RM_SHRINK:
> +		goto rm_shrink;
> +	default:
> +		break;
> +	}

I think this function could use at least a couple more prepatory
refactoring patches before we introduce the state machine...

>  
>  	error = xfs_attr_node_hasname(args, &state);
>  	if (error != -EEXIST)
>  		goto out;
> +	else
> +		error = 0;
>  
>  	/*
>  	 * If there is an out-of-line value, de-allocate the blocks.
> @@ -1221,6 +1281,14 @@ xfs_attr_node_removename(
>  	blk = &state->path.blk[ state->path.active-1 ];
>  	ASSERT(blk->bp != NULL);
>  	ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
> +
> +	/*
> +	 * Store blk and state in the context incase we need to cycle out the
> +	 * transaction
> +	 */
> +	args->dac.blk = blk;
> +	args->dac.da_state = state;
> +
>  	if (args->rmtblkno > 0) {
>  		/*
>  		 * Fill in disk block numbers in the state structure
> @@ -1239,13 +1307,40 @@ xfs_attr_node_removename(
>  		if (error)
>  			goto out;
>  
> -		error = xfs_trans_roll_inode(&args->trans, args->dp);
> -		if (error)
> -			goto out;
> +		args->dac.dela_state = XFS_DAS_RM_INVALIDATE;
> +		return -EAGAIN;
> +	}

The entire (args->rmtblkno > 0) branch above could be reduced into a
helper function. BTW, does it matter whether the invalidate occurs
before or after this particular transaction roll? It looks to me it just
makes in-core changes. I'm wondering if we could just fold that in as
well and eliminate that state entirely.

> +
> +rm_invalidate:
> +	args->dac.dela_state = XFS_DAS_RM_INVALIDATE;
>  
> -		error = xfs_attr_rmtval_remove(args);
> +	if (args->rmtblkno > 0) {
> +		error = xfs_attr_rmtval_invalidate(args);
>  		if (error)
>  			goto out;
> +	}
> +
> +rm_node_blks:
> +
> +	args->dac.dela_state = XFS_DAS_RM_NODE_BLKS;
> +	if (args->rmtblkno > 0) {
> +		/*
> +		 * Unmap value blocks for this attr.  This is similar to
> +		 * xfs_attr_rmtval_remove, but open coded here to return EAGAIN
> +		 * for new transactions
> +		 */
> +		while (!done && !error) {
> +			error = xfs_bunmapi(args->trans, args->dp,
> +				    args->rmtblkno, args->rmtblkcnt,
> +				    XFS_BMAPI_ATTRFORK, 1, &done);
> +			if (error)
> +				return error;
> +
> +			if (!done) {
> +				args->dac.dela_state = XFS_DAS_RM_NODE_BLKS;
> +				return -EAGAIN;
> +			}
> +		}
>  

The above could use the helper function treatment as well. E.g.,
something like xfs_attr_rmtval_unmap() that has a *done param this
function can check to determine whether to return -EAGAIN or proceed.

>  		/*
>  		 * Refill the state structure with buffers, the prior calls
> @@ -1271,17 +1366,14 @@ xfs_attr_node_removename(
>  		error = xfs_da3_join(state);
>  		if (error)
>  			goto out;
> -		error = xfs_defer_finish(&args->trans);
> -		if (error)
> -			goto out;

Hmm.. I think we might want to lift the xfs_defer_finish() call up into
the iter() function rather than just drop it. Otherwise this changes
behavior in that the transaction roll doesn't complete pending deferred
operations.

> -		/*
> -		 * Commit the Btree join operation and start a new trans.
> -		 */
> -		error = xfs_trans_roll_inode(&args->trans, dp);
> -		if (error)
> -			goto out;
> +
> +		args->dac.dela_state = XFS_DAS_RM_SHRINK;
> +		return -EAGAIN;
>  	}
>  
> +rm_shrink:
> +	args->dac.dela_state = XFS_DAS_RM_SHRINK;
> +
>  	/*
>  	 * If the result is small enough, push it all into the inode.
>  	 */
> @@ -1302,9 +1394,6 @@ xfs_attr_node_removename(
>  			/* bp is gone due to xfs_da_shrink_inode */
>  			if (error)
>  				goto out;
> -			error = xfs_defer_finish(&args->trans);
> -			if (error)
> -				goto out;
>  		} else
>  			xfs_trans_brelse(args->trans, bp);
>  	}

Same deal here (and same fundamental comment for the next patch)..
create a xfs_attr_node_shrink() or some such helper to make functions
that handle state smaller and easier to follow once the state bits are
introduced.

Brian

> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> index 3b5dad4..f6ac571 100644
> --- a/fs/xfs/libxfs/xfs_attr.h
> +++ b/fs/xfs/libxfs/xfs_attr.h
> @@ -152,6 +152,7 @@ int xfs_attr_set_args(struct xfs_da_args *args);
>  int xfs_attr_remove(struct xfs_inode *dp, struct xfs_name *name, int flags);
>  int xfs_has_attr(struct xfs_da_args *args);
>  int xfs_attr_remove_args(struct xfs_da_args *args);
> +int xfs_attr_remove_iter(struct xfs_da_args *args);
>  int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
>  		  int flags, struct attrlist_cursor_kern *cursor);
>  bool xfs_attr_namecheck(const void *name, size_t length);
> diff --git a/fs/xfs/libxfs/xfs_da_btree.h b/fs/xfs/libxfs/xfs_da_btree.h
> index 580fb72..137ec29 100644
> --- a/fs/xfs/libxfs/xfs_da_btree.h
> +++ b/fs/xfs/libxfs/xfs_da_btree.h
> @@ -49,10 +49,26 @@ enum xfs_dacmp {
>  	XFS_CMP_CASE		/* names are same but differ in case */
>  };
>  
> +enum xfs_delattr_state {
> +	XFS_DAS_RM_INVALIDATE	= 1, /* We are invalidating blocks */
> +	XFS_DAS_RM_SHRINK	= 2, /* We are shrinking the tree */
> +	XFS_DAS_RM_NODE_BLKS	= 3,/* We are removing node blocks */
> +};
> +
> +/*
> + * Context used for keeping track of delayed attribute operations
> + */
> +struct xfs_delattr_context {
> +	struct xfs_da_state	*da_state;
> +	struct xfs_da_state_blk *blk;
> +	enum xfs_delattr_state	dela_state;
> +};
> +
>  /*
>   * Structure to ease passing around component names.
>   */
>  typedef struct xfs_da_args {
> +	struct xfs_delattr_context dac;/* context used for delay attr ops */
>  	struct xfs_da_geometry *geo;	/* da block geometry */
>  	struct xfs_name	name;		/* name, length and argument  flags*/
>  	uint8_t		filetype;	/* filetype of inode for directories */
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index 1887605..9a649d1 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -24,6 +24,8 @@
>  #include "xfs_rmap_btree.h"
>  #include "xfs_log.h"
>  #include "xfs_trans_priv.h"
> +#include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_reflink.h"
>  #include "scrub/scrub.h"
> diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
> index 7b0e5b7..573e47e 100644
> --- a/fs/xfs/xfs_acl.c
> +++ b/fs/xfs/xfs_acl.c
> @@ -10,6 +10,8 @@
>  #include "xfs_trans_resv.h"
>  #include "xfs_mount.h"
>  #include "xfs_inode.h"
> +#include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_trace.h"
>  #include "xfs_error.h"
> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> index d37743b..881b9a4 100644
> --- a/fs/xfs/xfs_attr_list.c
> +++ b/fs/xfs/xfs_attr_list.c
> @@ -12,6 +12,7 @@
>  #include "xfs_trans_resv.h"
>  #include "xfs_mount.h"
>  #include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_inode.h"
>  #include "xfs_trans.h"
>  #include "xfs_bmap.h"
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 4fc8698..a31753f 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -15,6 +15,8 @@
>  #include "xfs_iwalk.h"
>  #include "xfs_itable.h"
>  #include "xfs_error.h"
> +#include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_bmap.h"
>  #include "xfs_bmap_util.h"
> diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
> index c4c4f09..4b693e3 100644
> --- a/fs/xfs/xfs_ioctl32.c
> +++ b/fs/xfs/xfs_ioctl32.c
> @@ -17,6 +17,8 @@
>  #include "xfs_itable.h"
>  #include "xfs_fsops.h"
>  #include "xfs_rtalloc.h"
> +#include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_ioctl.h"
>  #include "xfs_ioctl32.h"
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index e85bbf5..a2d299f 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -13,6 +13,8 @@
>  #include "xfs_inode.h"
>  #include "xfs_acl.h"
>  #include "xfs_quota.h"
> +#include "xfs_da_format.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_trans.h"
>  #include "xfs_trace.h"
> diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> index 5623682..8bdb972 100644
> --- a/fs/xfs/xfs_xattr.c
> +++ b/fs/xfs/xfs_xattr.c
> @@ -10,6 +10,7 @@
>  #include "xfs_log_format.h"
>  #include "xfs_da_format.h"
>  #include "xfs_inode.h"
> +#include "xfs_da_btree.h"
>  #include "xfs_attr.h"
>  #include "xfs_acl.h"
>  
> -- 
> 2.7.4
> 


  reply	other threads:[~2019-12-13 20:39 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-12  4:14 [PATCH v5 00/14] xfs: Delay Ready Attributes Allison Collins
2019-12-12  4:15 ` [PATCH v5 01/14] xfs: Remove all strlen in all xfs_attr_* functions for attr names Allison Collins
2019-12-12  4:15 ` [PATCH v5 02/14] xfs: Replace attribute parameters with struct xfs_name Allison Collins
2019-12-13 13:07   ` Brian Foster
2019-12-14  6:57     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 03/14] xfs: Embed struct xfs_name in xfs_da_args Allison Collins
2019-12-12  4:15 ` [PATCH v5 04/14] xfs: Add xfs_has_attr and subroutines Allison Collins
2019-12-13 13:08   ` Brian Foster
2019-12-14  6:58     ` Allison Collins
2019-12-24 12:18   ` Christoph Hellwig
2019-12-25  4:21     ` Allison Collins
2020-01-21 22:30       ` Darrick J. Wong
2020-01-22  0:25         ` Allison Collins
2020-01-25 16:27           ` Allison Collins
2020-01-25 23:08             ` Christoph Hellwig
2020-01-26  4:03               ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 05/14] xfs: Factor out new helper functions xfs_attr_rmtval_set Allison Collins
2019-12-24 12:14   ` Christoph Hellwig
2019-12-25 17:43     ` Allison Collins
2020-01-06 14:46       ` Brian Foster
2020-01-06 18:29         ` Allison Collins
2020-01-06 21:45           ` Darrick J. Wong
2020-01-06 23:33             ` Dave Chinner
2019-12-12  4:15 ` [PATCH v5 06/14] xfs: Factor up trans handling in xfs_attr3_leaf_flipflags Allison Collins
2019-12-24 12:16   ` Christoph Hellwig
2019-12-25 20:49     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 07/14] xfs: Factor out xfs_attr_leaf_addname helper Allison Collins
2019-12-13 14:15   ` Brian Foster
2019-12-14  6:58     ` Allison Collins
2019-12-24 12:22   ` Christoph Hellwig
2019-12-26 17:04     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 08/14] xfs: Factor up xfs_attr_try_sf_addname Allison Collins
2019-12-13 14:15   ` Brian Foster
2019-12-14  6:58     ` Allison Collins
2019-12-24 12:25   ` Christoph Hellwig
2019-12-27  3:23     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 09/14] xfs: Factor up trans roll from xfs_attr3_leaf_setflag Allison Collins
2019-12-24 12:26   ` Christoph Hellwig
2019-12-12  4:15 ` [PATCH v5 10/14] xfs: Factor out xfs_attr_rmtval_invalidate Allison Collins
2019-12-12  4:15 ` [PATCH v5 11/14] xfs: Factor up trans roll in xfs_attr3_leaf_clearflag Allison Collins
2019-12-24 12:28   ` Christoph Hellwig
2019-12-12  4:15 ` [PATCH v5 12/14] xfs: Check for -ENOATTR or -EEXIST Allison Collins
2019-12-13 14:16   ` Brian Foster
2019-12-14  7:56     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 13/14] xfs: Add delay ready attr remove routines Allison Collins
2019-12-13 17:30   ` Brian Foster [this message]
2019-12-14 19:21     ` Allison Collins
2019-12-24 12:30   ` Christoph Hellwig
2019-12-24 23:18     ` Allison Collins
2019-12-12  4:15 ` [PATCH v5 14/14] xfs: Add delay ready attr set routines Allison Collins
2019-12-24 12:02 ` [PATCH v5 00/14] xfs: Delay Ready Attributes Christoph Hellwig

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=20191213173046.GG43376@bfoster \
    --to=bfoster@redhat.com \
    --cc=allison.henderson@oracle.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox