Merge tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs

Pull configfs updates from Christoph Hellwig: "A fix from Nic for a race seen in production (including a stable tag). And while I'm sending you this I'm also sneaking in a trivial new helper from Bart so that we don't need inter-tree dependencies for the next merge window" * tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs: configfs: Introduce config_item_get_unless_zero() configfs: Fix race between create_link and configfs_rmdir

Linus Torvalds committed 9 years ago

Commit ab2789b2 parents 20223f0 19e72d33 files · +11 −3Browse files

Unified · Split

3 files

fs/configfs/item.c +8 −0
fs/configfs/symlink.c +1 −2
include/linux/configfs.h +2 −1

fs/configfs/item.c+8−0

@@ -138,6 +138,14 @@ struct config_item config_item_get(struct config_item item) · 137 unmodified lines
138	138	}
139	139	EXPORT_SYMBOL(config_item_get);
140	140
	141	+struct config_item config_item_get_unless_zero(struct config_item item)
	142	+{
	143	+ if (item && kref_get_unless_zero(&item->ci_kref))
	144	+ return item;
	145	+ return NULL;
	146	+}
	147	+EXPORT_SYMBOL(config_item_get_unless_zero);
	148	+
141	149	static void config_item_cleanup(struct config_item *item)
142	150	{
143	151	struct config_item_type *t = item->ci_type;

fs/configfs/symlink.c+1−2

@@ -83,14 +83,13 @@ static int create_link(struct config_item *parent_item, · 82 unmodified lines
83	83	ret = -ENOMEM;
84	84	sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL);
85	85	if (sl) {
86		− sl->sl_target = config_item_get(item);
87	86	spin_lock(&configfs_dirent_lock);
88	87	if (target_sd->s_type & CONFIGFS_USET_DROPPING) {
89	88	spin_unlock(&configfs_dirent_lock);
90		− config_item_put(item);
91	89	kfree(sl);
92	90	return -ENOENT;
93	91	}
	92	+ sl->sl_target = config_item_get(item);
94	93	list_add(&sl->sl_list, &target_sd->s_links);
95	94	spin_unlock(&configfs_dirent_lock);
96	95	ret = configfs_create_link(sl, parent_item->ci_dentry,

include/linux/configfs.h+2−1

@@ -74,7 +74,8 @@ extern void config_item_init_type_name(struct config_item *item, · 73 unmodified lines
74	74	const char *name,
75	75	struct config_item_type *type);
76	76
77		−extern struct config_item * config_item_get(struct config_item *);
	77	+extern struct config_item config_item_get(struct config_item );
	78	+extern struct config_item config_item_get_unless_zero(struct config_item );
78	79	extern void config_item_put(struct config_item *);
79	80
80	81	struct config_item_type {