Re: [PATCH v11 05/25] xfs: Split apart xfs_attr_leaf_addname

Darrick J. Wong
2020-07-21T23:21:49Z

On Mon, Jul 20, 2020 at 05:15:46PM -0700, Allison Collins wrote:
> Split out new helper function xfs_attr_leaf_try_add from
> xfs_attr_leaf_addname. Because new delayed attribute routines cannot
> roll transactions, we split off the parts of xfs_attr_leaf_addname that
> we can use, and move the commit into the calling function.
>
> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
> Reviewed-by: Brian Foster <bfoster@redhat.com>
> Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>

Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> fs/xfs/libxfs/xfs_attr.c | 95 +++++++++++++++++++++++++++++++-----------------
> 1 file changed, 61 insertions(+), 34 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index 28a9f8e..6fc6dc6 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -256,10 +256,31 @@ 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;
> +
> + /*
> + * Finish any deferred work items and roll the transaction once
> + * more. The goal here is to call node_addname with the inode
> + * and transaction in the same state (inode locked and joined,
> + * transaction clean) no matter how we got to this step.
> + */
> + 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;
> }
>
> @@ -507,20 +528,21 @@ xfs_attr_shortform_addname(xfs_da_args_t *args)
> *========================================================================*/
>
> /*
> - * Add a name to the leaf attribute list structure
> + * Tries to add an attribute to an inode in leaf form
> *
> - * This leaf block cannot have a "remote" value, we only call this routine
> - * if bmap_one_block() says there is only one block (ie: no remote blks).
> + * This function is meant to execute as part of a delayed operation and leaves
> + * the transaction handling to the caller. On success the attribute is added
> + * and the inode and transaction are left dirty. If there is not enough space,
> + * the attr data is converted to node format and -ENOSPC is returned. Caller is
> + * responsible for handling the dirty inode and transaction or adding the attr
> + * in node format.
> */
> STATIC int
> -xfs_attr_leaf_addname(
> - struct xfs_da_args *args)
> +xfs_attr_leaf_try_add(
> + struct xfs_da_args *args,
> + struct xfs_buf *bp)
> {
> - struct xfs_buf *bp;
> - int retval, error, forkoff;
> - struct xfs_inode *dp = args->dp;
> -
> - trace_xfs_attr_leaf_addname(args);
> + int retval, error;
>
> /*
> * Look up the given attribute in the leaf block. Figure out if
> @@ -562,31 +584,39 @@ 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
> */
> error = xfs_attr3_leaf_to_node(args);
> if (error)
> return error;
> - error = xfs_defer_finish(&args->trans);
> - if (error)
> - return error;
> + }
> + return retval;
> +out_brelse:
> + xfs_trans_brelse(args->trans, bp);
> + return retval;
> +}
>
> - /*
> - * Commit the current trans (including the inode) and start
> - * a new one.
> - */
> - error = xfs_trans_roll_inode(&args->trans, dp);
> - if (error)
> - return error;
>
> - /*
> - * Fob the whole rest of the problem off on the Btree code.
> - */
> - error = xfs_attr_node_addname(args);
> +/*
> + * Add a name to the leaf attribute list structure
> + *
> + * This leaf block cannot have a "remote" value, we only call this routine
> + * if bmap_one_block() says there is only one block (ie: no remote blks).
> + */
> +STATIC int
> +xfs_attr_leaf_addname(
> + struct xfs_da_args *args)
> +{
> + int error, forkoff;
> + struct xfs_buf *bp = NULL;
> + struct xfs_inode *dp = args->dp;
> +
> + trace_xfs_attr_leaf_addname(args);
> +
> + error = xfs_attr_leaf_try_add(args, bp);
> + if (error)
> return error;
> - }
>
> /*
> * Commit the transaction that added the attr name so that
> @@ -681,9 +711,6 @@ xfs_attr_leaf_addname(
> error = xfs_attr3_leaf_clearflag(args);
> }
> return error;
> -out_brelse:
> - xfs_trans_brelse(args->trans, bp);
> - return retval;
> }
>
> /*
> --
> 2.7.4
>