diff options
Diffstat (limited to 'fs/sysfs/dir.c')
-rw-r--r-- | fs/sysfs/dir.c | 75 |
1 files changed, 64 insertions, 11 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 105a7e2..0cdfd81 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; |