fs/ubifs: use rbtree postorder iteration helper instead of opencoding

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 17 insertions, 114 deletions

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index cc1febd8fadf..5157b866a853 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2118,26 +2118,10 @@ out_free:
  */
 static void free_inodes(struct fsck_data *fsckd)
 {
-        struct rb_node *this = fsckd->inodes.rb_node;
-        struct fsck_inode *fscki;
+        struct fsck_inode *fscki, *n;
 
-        while (this) {
-                if (this->rb_left)
-                        this = this->rb_left;
-                else if (this->rb_right)
-                        this = this->rb_right;
-                else {
-                        fscki = rb_entry(this, struct fsck_inode, rb);
-                        this = rb_parent(this);
-                        if (this) {
-                                if (this->rb_left == &fscki->rb)
-                                        this->rb_left = NULL;
-                                else
-                                        this->rb_right = NULL;
-                        }
-                        kfree(fscki);
-                }
-        }
+        rbtree_postorder_for_each_entry_safe(fscki, n, &fsckd->inodes, rb)
+                kfree(fscki);
 }
 
 /**
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index 36bd4efd0819..a902c5919e42 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -574,27 +574,10 @@ static int done_already(struct rb_root *done_tree, int lnum)
  */
 static void destroy_done_tree(struct rb_root *done_tree)
 {
-        struct rb_node *this = done_tree->rb_node;
-        struct done_ref *dr;
+        struct done_ref *dr, *n;
 
-        while (this) {
-                if (this->rb_left) {
-                        this = this->rb_left;
-                        continue;
-                } else if (this->rb_right) {
-                        this = this->rb_right;
-                        continue;
-                }
-                dr = rb_entry(this, struct done_ref, rb);
-                this = rb_parent(this);
-                if (this) {
-                        if (this->rb_left == &dr->rb)
-                                this->rb_left = NULL;
-                        else
-                                this->rb_right = NULL;
-                }
+        rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb)
                 kfree(dr);
-        }
 }
 
 /**
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
index ba32da3fe08a..f1c3e5a1b315 100644
--- a/fs/ubifs/orphan.c
+++ b/fs/ubifs/orphan.c
@@ -815,27 +815,10 @@ static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
 
 static void dbg_free_check_tree(struct rb_root *root)
 {
-        struct rb_node *this = root->rb_node;
-        struct check_orphan *o;
+        struct check_orphan *o, *n;
 
-        while (this) {
-                if (this->rb_left) {
-                        this = this->rb_left;
-                        continue;
-                } else if (this->rb_right) {
-                        this = this->rb_right;
-                        continue;
-                }
-                o = rb_entry(this, struct check_orphan, rb);
-                this = rb_parent(this);
-                if (this) {
-                        if (this->rb_left == &o->rb)
-                                this->rb_left = NULL;
-                        else
-                                this->rb_right = NULL;
-                }
+        rbtree_postorder_for_each_entry_safe(o, n, root, rb)
                 kfree(o);
-        }
 }
 
 static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c
index 065096e36ed9..c14adb2f420c 100644
--- a/fs/ubifs/recovery.c
+++ b/fs/ubifs/recovery.c
@@ -1335,29 +1335,14 @@ static void remove_ino(struct ubifs_info *c, ino_t inum)
  */
 void ubifs_destroy_size_tree(struct ubifs_info *c)
 {
-        struct rb_node *this = c->size_tree.rb_node;
-        struct size_entry *e;
+        struct size_entry *e, *n;
 
-        while (this) {
-                if (this->rb_left) {
-                        this = this->rb_left;
-                        continue;
-                } else if (this->rb_right) {
-                        this = this->rb_right;
-                        continue;
-                }
-                e = rb_entry(this, struct size_entry, rb);
+        rbtree_postorder_for_each_entry_safe(e, n, &c->size_tree, rb) {
                 if (e->inode)
                         iput(e->inode);
-                this = rb_parent(this);
-                if (this) {
-                        if (this->rb_left == &e->rb)
-                                this->rb_left = NULL;
-                        else
-                                this->rb_right = NULL;
-                }
                 kfree(e);
         }
+
         c->size_tree = RB_ROOT;
 }
 
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index f69daa514a57..5ded8490c0c6 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -873,26 +873,10 @@ static void free_orphans(struct ubifs_info *c)
  */
 static void free_buds(struct ubifs_info *c)
 {
-        struct rb_node *this = c->buds.rb_node;
-        struct ubifs_bud *bud;
-
-        while (this) {
-                if (this->rb_left)
-                        this = this->rb_left;
-                else if (this->rb_right)
-                        this = this->rb_right;
-                else {
-                        bud = rb_entry(this, struct ubifs_bud, rb);
-                        this = rb_parent(this);
-                        if (this) {
-                                if (this->rb_left == &bud->rb)
-                                        this->rb_left = NULL;
-                                else
-                                        this->rb_right = NULL;
-                        }
-                        kfree(bud);
-                }
-        }
+        struct ubifs_bud *bud, *n;
+
+        rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
+                kfree(bud);
 }
 
 /**
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 349f31a30f40..9083bc7ed4ae 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -178,27 +178,11 @@ static int ins_clr_old_idx_znode(struct ubifs_info *c,
  */
 void destroy_old_idx(struct ubifs_info *c)
 {
-        struct rb_node *this = c->old_idx.rb_node;
-        struct ubifs_old_idx *old_idx;
+        struct ubifs_old_idx *old_idx, *n;
 
-        while (this) {
-                if (this->rb_left) {
-                        this = this->rb_left;
-                        continue;
-                } else if (this->rb_right) {
-                        this = this->rb_right;
-                        continue;
-                }
-                old_idx = rb_entry(this, struct ubifs_old_idx, rb);
-                this = rb_parent(this);
-                if (this) {
-                        if (this->rb_left == &old_idx->rb)
-                                this->rb_left = NULL;
-                        else
-                                this->rb_right = NULL;
-                }
+        rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb)
                 kfree(old_idx);
-        }
+
         c->old_idx = RB_ROOT;
 }