xfs: clean up final attr removal in xfs_attr_set_iter

Clean up the final leaf/node states in xfs_attr_set_iter() to
further simplify the high level state machine and to set the
completion state correctly. As we are adding a separate state
for node format removal, we need to ensure that node formats
are collapsed back to shortform or empty correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson<allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

3 files changed, 94 insertions, 72 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index c0e72e9c4f53..467e23602005 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -60,7 +60,7 @@ STATIC int xfs_attr_node_get(xfs_da_args_t *args);
 STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
 static int xfs_attr_node_try_addname(struct xfs_attr_item *attr);
 STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_item *attr);
-STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_attr_item *attr);
+STATIC int xfs_attr_node_remove_attr(struct xfs_attr_item *attr);
 STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
 				 struct xfs_da_state **state);
 STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
@@ -444,6 +444,77 @@ out:
 }
 
 /*
+ * Remove the original attr we have just replaced. This is dependent on the
+ * original lookup and insert placing the old attr in args->blkno/args->index
+ * and the new attr in args->blkno2/args->index2.
+ */
+static int
+xfs_attr_leaf_remove_attr(
+	struct xfs_attr_item		*attr)
+{
+	struct xfs_da_args              *args = attr->xattri_da_args;
+	struct xfs_inode		*dp = args->dp;
+	struct xfs_buf			*bp = NULL;
+	int				forkoff;
+	int				error;
+
+	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
+				   &bp);
+	if (error)
+		return error;
+
+	xfs_attr3_leaf_remove(bp, args);
+
+	forkoff = xfs_attr_shortform_allfit(bp, dp);
+	if (forkoff)
+		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
+		/* bp is gone due to xfs_da_shrink_inode */
+
+	return error;
+}
+
+/*
+ * Shrink an attribute from leaf to shortform. Used by the node format remove
+ * path when the node format collapses to a single block and so we have to check
+ * if it can be collapsed further.
+ */
+static int
+xfs_attr_leaf_shrink(
+	struct xfs_da_args	*args,
+	struct xfs_da_state     *state)
+{
+	struct xfs_inode	*dp = args->dp;
+	int			error, forkoff;
+	struct xfs_buf		*bp;
+
+	if (!xfs_attr_is_leaf(dp))
+		return 0;
+
+	/*
+	 * Have to get rid of the copy of this dabuf in the state.
+	 */
+	if (state) {
+		ASSERT(state->path.active == 1);
+		ASSERT(state->path.blk[0].bp);
+		state->path.blk[0].bp = NULL;
+	}
+
+	error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
+	if (error)
+		return error;
+
+	forkoff = xfs_attr_shortform_allfit(bp, dp);
+	if (forkoff) {
+		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
+		/* bp is gone due to xfs_da_shrink_inode */
+	} else {
+		xfs_trans_brelse(args->trans, bp);
+	}
+
+	return error;
+}
+
+/*
  * Set the attribute specified in @args.
  * This routine is meant to function as a delayed operation, and may return
  * -EAGAIN when the transaction needs to be rolled.  Calling functions will need
@@ -455,9 +526,7 @@ xfs_attr_set_iter(
 	struct xfs_attr_item		*attr)
 {
 	struct xfs_da_args              *args = attr->xattri_da_args;
-	struct xfs_inode		*dp = args->dp;
-	struct xfs_buf			*bp = NULL;
-	int				forkoff, error = 0;
+	int				error = 0;
 
 	/* State machine switch */
 next_state:
@@ -548,32 +617,16 @@ next_state:
 		attr->xattri_dela_state++;
 		break;
 
-	case XFS_DAS_RD_LEAF:
-		/*
-		 * This is the last step for leaf format. Read the block with
-		 * the old attr, remove the old attr, check for shortform
-		 * conversion and return.
-		 */
-		error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
-					   &bp);
-		if (error)
-			return error;
-
-		xfs_attr3_leaf_remove(bp, args);
-
-		forkoff = xfs_attr_shortform_allfit(bp, dp);
-		if (forkoff)
-			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
-			/* bp is gone due to xfs_da_shrink_inode */
-
-		return error;
+	case XFS_DAS_LEAF_REMOVE_ATTR:
+		error = xfs_attr_leaf_remove_attr(attr);
+		attr->xattri_dela_state = XFS_DAS_DONE;
+		break;
 
-	case XFS_DAS_CLR_FLAG:
-		/*
-		 * The last state for node format. Look up the old attr and
-		 * remove it.
-		 */
-		error = xfs_attr_node_addname_clear_incomplete(attr);
+	case XFS_DAS_NODE_REMOVE_ATTR:
+		error = xfs_attr_node_remove_attr(attr);
+		if (!error)
+			error = xfs_attr_leaf_shrink(args, NULL);
+		attr->xattri_dela_state = XFS_DAS_DONE;
 		break;
 	default:
 		ASSERT(0);
@@ -1268,8 +1321,8 @@ out:
 }
 
 
-STATIC int
-xfs_attr_node_addname_clear_incomplete(
+static int
+xfs_attr_node_remove_attr(
 	struct xfs_attr_item		*attr)
 {
 	struct xfs_da_args		*args = attr->xattri_da_args;
@@ -1310,38 +1363,6 @@ out:
 	return retval;
 }
 
-/*
- * Shrink an attribute from leaf to shortform
- */
-STATIC int
-xfs_attr_node_shrink(
-	struct xfs_da_args	*args,
-	struct xfs_da_state     *state)
-{
-	struct xfs_inode	*dp = args->dp;
-	int			error, forkoff;
-	struct xfs_buf		*bp;
-
-	/*
-	 * Have to get rid of the copy of this dabuf in the state.
-	 */
-	ASSERT(state->path.active == 1);
-	ASSERT(state->path.blk[0].bp);
-	state->path.blk[0].bp = NULL;
-
-	error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
-	if (error)
-		return error;
-
-	forkoff = xfs_attr_shortform_allfit(bp, dp);
-	if (forkoff) {
-		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
-		/* bp is gone due to xfs_da_shrink_inode */
-	} else
-		xfs_trans_brelse(args->trans, bp);
-
-	return error;
-}
 
 /*
  * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
@@ -1550,7 +1571,7 @@ xfs_attr_remove_iter(
 		 * transaction.
 		 */
 		if (xfs_attr_is_leaf(dp))
-			error = xfs_attr_node_shrink(args, state);
+			error = xfs_attr_leaf_shrink(args, state);
 		ASSERT(error != -EAGAIN);
 		break;
 	default:
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 1e038c23029a..7b0a5a165725 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -451,21 +451,21 @@ enum xfs_delattr_state {
 	XFS_DAS_RM_NAME,		/* Remove attr name */
 	XFS_DAS_RM_SHRINK,		/* We are shrinking the tree */
 
-	/* Leaf state set sequence */
+	/* Leaf state set/replace sequence */
 	XFS_DAS_LEAF_SET_RMT,		/* set a remote xattr from a leaf */
 	XFS_DAS_LEAF_ALLOC_RMT,		/* We are allocating remote blocks */
 	XFS_DAS_LEAF_REPLACE,		/* Perform replace ops on a leaf */
 	XFS_DAS_LEAF_REMOVE_OLD,	/* Start removing old attr from leaf */
 	XFS_DAS_LEAF_REMOVE_RMT,	/* A rename is removing remote blocks */
-	XFS_DAS_RD_LEAF,		/* Read in the new leaf */
+	XFS_DAS_LEAF_REMOVE_ATTR,	/* Remove the old attr from a leaf */
 
-	/* Node state set sequence, must match leaf state above */
+	/* Node state set/replace sequence, must match leaf state above */
 	XFS_DAS_NODE_SET_RMT,		/* set a remote xattr from a node */
 	XFS_DAS_NODE_ALLOC_RMT,		/* We are allocating remote blocks */
 	XFS_DAS_NODE_REPLACE,		/* Perform replace ops on a node */
 	XFS_DAS_NODE_REMOVE_OLD,	/* Start removing old attr from node */
 	XFS_DAS_NODE_REMOVE_RMT,	/* A rename is removing remote blocks */
-	XFS_DAS_CLR_FLAG,		/* Clear incomplete flag */
+	XFS_DAS_NODE_REMOVE_ATTR,	/* Remove the old attr from a node */
 
 	XFS_DAS_DONE,			/* finished operation */
 };
@@ -483,13 +483,13 @@ enum xfs_delattr_state {
 	{ XFS_DAS_LEAF_REPLACE,		"XFS_DAS_LEAF_REPLACE" }, \
 	{ XFS_DAS_LEAF_REMOVE_OLD,	"XFS_DAS_LEAF_REMOVE_OLD" }, \
 	{ XFS_DAS_LEAF_REMOVE_RMT,	"XFS_DAS_LEAF_REMOVE_RMT" }, \
-	{ XFS_DAS_RD_LEAF,		"XFS_DAS_RD_LEAF" }, \
+	{ XFS_DAS_LEAF_REMOVE_ATTR,	"XFS_DAS_LEAF_REMOVE_ATTR" }, \
 	{ XFS_DAS_NODE_SET_RMT,		"XFS_DAS_NODE_SET_RMT" }, \
 	{ XFS_DAS_NODE_ALLOC_RMT,	"XFS_DAS_NODE_ALLOC_RMT" },  \
 	{ XFS_DAS_NODE_REPLACE,		"XFS_DAS_NODE_REPLACE" },  \
 	{ XFS_DAS_NODE_REMOVE_OLD,	"XFS_DAS_NODE_REMOVE_OLD" }, \
 	{ XFS_DAS_NODE_REMOVE_RMT,	"XFS_DAS_NODE_REMOVE_RMT" }, \
-	{ XFS_DAS_CLR_FLAG,		"XFS_DAS_CLR_FLAG" }, \
+	{ XFS_DAS_NODE_REMOVE_ATTR,	"XFS_DAS_NODE_REMOVE_ATTR" }, \
 	{ XFS_DAS_DONE,			"XFS_DAS_DONE" }
 
 /*
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 793d2a86ab2c..260760ce2d05 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -4141,13 +4141,14 @@ TRACE_DEFINE_ENUM(XFS_DAS_LEAF_ALLOC_RMT);
 TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REPLACE);
 TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REMOVE_OLD);
 TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REMOVE_RMT);
-TRACE_DEFINE_ENUM(XFS_DAS_RD_LEAF);
+TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REMOVE_ATTR);
 TRACE_DEFINE_ENUM(XFS_DAS_NODE_SET_RMT);
 TRACE_DEFINE_ENUM(XFS_DAS_NODE_ALLOC_RMT);
 TRACE_DEFINE_ENUM(XFS_DAS_NODE_REPLACE);
 TRACE_DEFINE_ENUM(XFS_DAS_NODE_REMOVE_OLD);
 TRACE_DEFINE_ENUM(XFS_DAS_NODE_REMOVE_RMT);
-TRACE_DEFINE_ENUM(XFS_DAS_CLR_FLAG);
+TRACE_DEFINE_ENUM(XFS_DAS_NODE_REMOVE_ATTR);
+TRACE_DEFINE_ENUM(XFS_DAS_DONE);
 
 DECLARE_EVENT_CLASS(xfs_das_state_class,
 	TP_PROTO(int das, struct xfs_inode *ip),