kernfs: do not alloc iattrs in kernfs_xattr_get (d0c9c153) · Commits · 戴 / test

fs/kernfs/inode.c

+14 −4

Original line number	Original line	Diff line number	Diff line
	@@ -31,14 +31,14 @@ static const struct inode_operations kernfs_iops = {
	.listxattr = kernfs_iop_listxattr,		.listxattr = kernfs_iop_listxattr,
	};		};

	static struct kernfs_iattrs kernfs_iattrs(struct kernfs_node kn)		static struct kernfs_iattrs __kernfs_iattrs(struct kernfs_node kn, int alloc)
	{		{
	static DEFINE_MUTEX(iattr_mutex);		static DEFINE_MUTEX(iattr_mutex);
	struct kernfs_iattrs *ret;		struct kernfs_iattrs *ret;

	mutex_lock(&iattr_mutex);		mutex_lock(&iattr_mutex);

	if (kn->iattr)		if (kn->iattr \|\| !alloc)
	goto out_unlock;		goto out_unlock;

	kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);		kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);
	@@ -60,6 +60,16 @@ out_unlock:
	return ret;		return ret;
	}		}

			static struct kernfs_iattrs kernfs_iattrs(struct kernfs_node kn)
			{
			return __kernfs_iattrs(kn, 1);
			}

			static struct kernfs_iattrs kernfs_iattrs_noalloc(struct kernfs_node kn)
			{
			return __kernfs_iattrs(kn, 0);
			}

	int __kernfs_setattr(struct kernfs_node kn, const struct iattr iattr)		int __kernfs_setattr(struct kernfs_node kn, const struct iattr iattr)
	{		{
	struct kernfs_iattrs *attrs;		struct kernfs_iattrs *attrs;
	@@ -306,9 +316,9 @@ static int kernfs_xattr_get(const struct xattr_handler *handler,
	struct kernfs_node *kn = inode->i_private;		struct kernfs_node *kn = inode->i_private;
	struct kernfs_iattrs *attrs;		struct kernfs_iattrs *attrs;

	attrs = kernfs_iattrs(kn);		attrs = kernfs_iattrs_noalloc(kn);
	if (!attrs)		if (!attrs)
	return -ENOMEM;		return -ENODATA;

	return simple_xattr_get(&attrs->xattrs, name, value, size);		return simple_xattr_get(&attrs->xattrs, name, value, size);
	}		}

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