From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f48.google.com ([74.125.82.48]:38643 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758192AbcILT3i (ORCPT ); Mon, 12 Sep 2016 15:29:38 -0400 Received: by mail-wm0-f48.google.com with SMTP id 1so163056237wmz.1 for ; Mon, 12 Sep 2016 12:29:37 -0700 (PDT) From: Miklos Szeredi To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Al Viro Subject: [PATCH 10/17] nsfs: clean up ns_get_name() interface Date: Mon, 12 Sep 2016 21:29:12 +0200 Message-Id: <1473708559-12714-11-git-send-email-mszeredi@redhat.com> In-Reply-To: <1473708559-12714-1-git-send-email-mszeredi@redhat.com> References: <1473708559-12714-1-git-send-email-mszeredi@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The only user of this is proc_ns_get_link(), which needs an allocated buffer. And ns_get_name() is much better positioned to know the size of the buffer to allocate, since it's the one that is going to fill it. Signed-off-by: Miklos Szeredi --- fs/nsfs.c | 17 +++++++++++++---- fs/proc/namespaces.c | 20 +++----------------- include/linux/proc_ns.h | 4 ++-- 3 files changed, 18 insertions(+), 23 deletions(-) diff --git a/fs/nsfs.c b/fs/nsfs.c index 8f20d6016e20..33ec85b91aba 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -5,6 +5,7 @@ #include #include #include +#include static struct vfsmount *nsfs_mnt; @@ -106,14 +107,22 @@ slow: goto got_it; } -int ns_get_name(char *buf, size_t size, struct task_struct *task, - const struct proc_ns_operations *ns_ops) +char *ns_get_name(struct task_struct *task, + const struct proc_ns_operations *ns_ops) { struct ns_common *ns; - int res = -ENOENT; + char *res = ERR_PTR(-ENOENT); + ns = ns_ops->get(task); if (ns) { - res = snprintf(buf, size, "%s:[%u]", ns_ops->name, ns->inum); + /* 10 for unsigned int in decimal + 3 extra chars + term null */ + size_t size = strlen(ns_ops->name) + 14; + + res = kmalloc(size, GFP_KERNEL); + if (!res) + res = ERR_PTR(-ENOMEM); + else + snprintf(res, size, "%s:[%u]", ns_ops->name, ns->inum); ns_ops->put(ns); } return res; diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 9c9a1683791a..9c7209734b05 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -33,8 +33,6 @@ static const struct proc_ns_operations *ns_entries[] = { #endif }; -#define PROC_NS_LINK_MAX 50 - static const char *proc_ns_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) @@ -59,21 +57,9 @@ static const char *proc_ns_get_link(struct dentry *dentry, if (!res) nd_jump_link(&ns_path); } else { - char *name = kmalloc(PROC_NS_LINK_MAX, GFP_KERNEL); - int err; - - res = ERR_PTR(-ENOMEM); - if (!name) - goto out_put; - - err = ns_get_name(name, PROC_NS_LINK_MAX, task, ns_ops); - if (err < 0) { - kfree(name); - res = ERR_PTR(err); - goto out_put; - } - set_delayed_call(done, kfree_link, name); - res = name; + res = ns_get_name(task, ns_ops); + if (!IS_ERR(res)) + set_delayed_call(done, kfree_link, res); } out_put: put_task_struct(task); diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index de0e7719d4c5..9ab3fb9b9101 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -74,8 +74,8 @@ extern struct file *proc_ns_fget(int fd); extern void *ns_get_path(struct path *path, struct task_struct *task, const struct proc_ns_operations *ns_ops); -extern int ns_get_name(char *buf, size_t size, struct task_struct *task, - const struct proc_ns_operations *ns_ops); +char *ns_get_name(struct task_struct *task, + const struct proc_ns_operations *ns_ops); extern void nsfs_init(void); #endif /* _LINUX_PROC_NS_H */ -- 2.5.5