configfs: new object reprsenting tree fragments
commit 47320fbe11a6059ae502c9c16b668022fdb4cf76 upstream.
Refcounted, hangs of configfs_dirent, created by operations that add
fragments to configfs tree (mkdir and configfs_register_{subsystem,group}).
Will be used in the next commit to provide exclusion between fragment
removal and ->show/->store calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index ccc31fa..16eb59a 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -34,6 +34,15 @@
#include <linux/list.h>
#include <linux/spinlock.h>
+struct configfs_fragment {
+ atomic_t frag_count;
+ struct rw_semaphore frag_sem;
+ bool frag_dead;
+};
+
+void put_fragment(struct configfs_fragment *);
+struct configfs_fragment *get_fragment(struct configfs_fragment *);
+
struct configfs_dirent {
atomic_t s_count;
int s_dependent_count;
@@ -48,6 +57,7 @@
#ifdef CONFIG_LOCKDEP
int s_depth;
#endif
+ struct configfs_fragment *s_frag;
};
#define CONFIGFS_ROOT 0x0001
@@ -75,8 +85,8 @@
extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
extern int configfs_create_bin_file(struct config_item *,
const struct configfs_bin_attribute *);
-extern int configfs_make_dirent(struct configfs_dirent *,
- struct dentry *, void *, umode_t, int);
+extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
+ void *, umode_t, int, struct configfs_fragment *);
extern int configfs_dirent_is_ready(struct configfs_dirent *);
extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
@@ -151,6 +161,7 @@
{
if (!(sd->s_type & CONFIGFS_ROOT)) {
kfree(sd->s_iattr);
+ put_fragment(sd->s_frag);
kmem_cache_free(configfs_dir_cachep, sd);
}
}