[PATCH v7 16/19] xfs: Simplify xfs_attr_set_iter

Allison Collins
2020-02-23T02:06:26Z

Delayed attribute mechanics make frequent use of goto statements. We can use this
to further simplify xfs_attr_set_iter. Because states tend to fall between if
conditions, we can invert the if logic and jump to the goto. This helps to reduce
indentation and simplify things.

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
---
fs/xfs/libxfs/xfs_attr.c | 71 ++++++++++++++++++++++++++++--------------------
1 file changed, 42 insertions(+), 29 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 30a16fe..dd935ff 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -254,6 +254,19 @@ xfs_attr_try_sf_addname(
}

/*
+ * Check to see if the attr should be upgraded from non-existent or shortform to
+ * single-leaf-block attribute list.
+ */
+static inline bool
+xfs_attr_fmt_needs_update(
+ struct xfs_inode *dp)
+{
+ return dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
+ (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
+ dp->i_d.di_anextents == 0);
+}
+
+/*
* Set the attribute specified in @args.
*/
int
@@ -342,40 +355,40 @@ xfs_attr_set_iter(
}

/*
- * If the attribute list is non-existent or a shortform list,
- * upgrade it to a single-leaf-block attribute list.
+ * If the attribute list is already in leaf format, jump straight to
+ * leaf handling. Otherwise, try to add the attribute to the shortform
+ * list; if there's no room then convert the list to leaf format and try
+ * again.
*/
- if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
- (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
- dp->i_d.di_anextents == 0)) {
+ if (!xfs_attr_fmt_needs_update(dp))
+ goto add_leaf;

- /*
- * Try to add the attr to the attribute list in the inode.
- */
- error = xfs_attr_try_sf_addname(dp, args);
+ /*
+ * Try to add the attr to the attribute list in the inode.
+ */
+ error = xfs_attr_try_sf_addname(dp, args);

- /* Should only be 0, -EEXIST or ENOSPC */
- if (error != -ENOSPC)
- return error;
+ /* Should only be 0, -EEXIST or ENOSPC */
+ if (error != -ENOSPC)
+ return error;

- /*
- * It won't fit in the shortform, transform to a leaf block.
- * GROT: another possible req'mt for a double-split btree op.
- */
- error = xfs_attr_shortform_to_leaf(args, leaf_bp);
- if (error)
- return error;
+ /*
+ * It won't fit in the shortform, transform to a leaf block.
+ * GROT: another possible req'mt for a double-split btree op.
+ */
+ error = xfs_attr_shortform_to_leaf(args, leaf_bp);
+ if (error)
+ return error;

- /*
- * Prevent the leaf buffer from being unlocked so that a
- * concurrent AIL push cannot grab the half-baked leaf
- * buffer and run into problems with the write verifier.
- */
- xfs_trans_bhold(args->trans, *leaf_bp);
- args->dac.flags |= XFS_DAC_FINISH_TRANS;
- args->dac.dela_state = XFS_DAS_ADD_LEAF;
- return -EAGAIN;
- }
+ /*
+ * Prevent the leaf buffer from being unlocked so that a
+ * concurrent AIL push cannot grab the half-baked leaf
+ * buffer and run into problems with the write verifier.
+ */
+ xfs_trans_bhold(args->trans, *leaf_bp);
+ args->dac.flags |= XFS_DAC_FINISH_TRANS;
+ args->dac.dela_state = XFS_DAS_ADD_LEAF;
+ return -EAGAIN;

add_leaf:

--
2.7.4