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Commit 7d35079f authored by Shaohua Li's avatar Shaohua Li Committed by Jens Axboe
Browse files

kernfs: use idr instead of ida to manage inode number 



kernfs uses ida to manage inode number. The problem is we can't get
kernfs_node from inode number with ida. Switching to use idr, next patch
will add an API to get kernfs_node from inode number.

Acked-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0a07b238

fs/kernfs/dir.c

+12 −5
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
DEFINE_MUTEX(kernfs_mutex);

static DEFINE_SPINLOCK(kernfs_rename_lock);	/* kn->parent and ->name */

static char kernfs_pr_cont_buf[PATH_MAX];	/* protected by rename_lock */

static DEFINE_SPINLOCK(kernfs_idr_lock);	/* root->ino_idr */



#define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb)
@@ -533,7 +534,9 @@ void kernfs_put(struct kernfs_node *kn) 
		simple_xattrs_free(&kn->iattr->xattrs);

	}

	kfree(kn->iattr);

	ida_simple_remove(&root->ino_ida, kn->ino);

	spin_lock(&kernfs_idr_lock);

	idr_remove(&root->ino_idr, kn->ino);

	spin_unlock(&kernfs_idr_lock);

	kmem_cache_free(kernfs_node_cache, kn);



	kn = parent;
@@ -542,7 +545,7 @@ void kernfs_put(struct kernfs_node *kn) 
			goto repeat;

	} else {

		/* just released the root kn, free @root too */

		ida_destroy(&root->ino_ida);

		idr_destroy(&root->ino_idr);

		kfree(root);

	}

}
@@ -630,7 +633,11 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, 
	if (!kn)

		goto err_out1;



	ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL);

	idr_preload(GFP_KERNEL);

	spin_lock(&kernfs_idr_lock);

	ret = idr_alloc(&root->ino_idr, kn, 1, 0, GFP_ATOMIC);

	spin_unlock(&kernfs_idr_lock);

	idr_preload_end();

	if (ret < 0)

		goto err_out2;

	kn->ino = ret;
@@ -875,13 +882,13 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, 
	if (!root)

		return ERR_PTR(-ENOMEM);



	ida_init(&root->ino_ida);

	idr_init(&root->ino_idr);

	INIT_LIST_HEAD(&root->supers);



	kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO,

			       KERNFS_DIR);

	if (!kn) {

		ida_destroy(&root->ino_ida);

		idr_destroy(&root->ino_idr);

		kfree(root);

		return ERR_PTR(-ENOMEM);

	}

include/linux/kernfs.h

+1 −1
Original line number Diff line number Diff line
@@ -163,7 +163,7 @@ struct kernfs_root { 
	unsigned int		flags;	/* KERNFS_ROOT_* flags */



	/* private fields, do not use outside kernfs proper */

	struct ida		ino_ida;

	struct idr		ino_idr;

	struct kernfs_syscall_ops *syscall_ops;



	/* list of kernfs_super_info of this root, protected by kernfs_mutex */