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-rw-r--r--fs/sysfs/dir.c75
1 files changed, 64 insertions, 11 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 105a7e2d1660..0cdfd8128d3e 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -789,27 +789,81 @@ void sysfs_remove_subdir(struct sysfs_dirent *sd)
remove_dir(sd);
}
+static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos)
+{
+ struct sysfs_dirent *last;
+
+ while (true) {
+ struct rb_node *rbn;
+
+ last = pos;
+
+ if (sysfs_type(pos) != SYSFS_DIR)
+ break;
+
+ rbn = rb_first(&pos->s_dir.children);
+ if (!rbn)
+ break;
+
+ pos = to_sysfs_dirent(rbn);
+ }
+
+ return last;
+}
+
+/**
+ * sysfs_next_descendant_post - find the next descendant for post-order walk
+ * @pos: the current position (%NULL to initiate traversal)
+ * @root: sysfs_dirent whose descendants to walk
+ *
+ * Find the next descendant to visit for post-order traversal of @root's
+ * descendants. @root is included in the iteration and the last node to be
+ * visited.
+ */
+static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos,
+ struct sysfs_dirent *root)
+{
+ struct rb_node *rbn;
+
+ lockdep_assert_held(&sysfs_mutex);
+
+ /* if first iteration, visit leftmost descendant which may be root */
+ if (!pos)
+ return sysfs_leftmost_descendant(root);
+
+ /* if we visited @root, we're done */
+ if (pos == root)
+ return NULL;
+
+ /* if there's an unvisited sibling, visit its leftmost descendant */
+ rbn = rb_next(&pos->s_rb);
+ if (rbn)
+ return sysfs_leftmost_descendant(to_sysfs_dirent(rbn));
+
+ /* no sibling left, visit parent */
+ return pos->s_parent;
+}
static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
{
struct sysfs_addrm_cxt acxt;
- struct rb_node *pos;
+ struct sysfs_dirent *pos, *next;
if (!dir_sd)
return;
pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
sysfs_addrm_start(&acxt);
- pos = rb_first(&dir_sd->s_dir.children);
- while (pos) {
- struct sysfs_dirent *sd = to_sysfs_dirent(pos);
- pos = rb_next(pos);
- if (sysfs_type(sd) != SYSFS_DIR)
- sysfs_remove_one(&acxt, sd);
- }
- sysfs_addrm_finish(&acxt);
- remove_dir(dir_sd);
+ next = NULL;
+ do {
+ pos = next;
+ next = sysfs_next_descendant_post(pos, dir_sd);
+ if (pos)
+ sysfs_remove_one(&acxt, pos);
+ } while (next);
+
+ sysfs_addrm_finish(&acxt);
}
/**
@@ -820,7 +874,6 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
* the directory before we remove the directory, and we've inlined
* what used to be sysfs_rmdir() below, instead of calling separately.
*/
-
void sysfs_remove_dir(struct kobject *kobj)
{
struct sysfs_dirent *sd = kobj->sd;