From: zwu.kernel@gmail.com Subject: [RFC v4+ hot_track 13/19] debugfs: introduce one function Date: Mon, 29 Oct 2012 12:30:55 +0800 Message-ID: <1351485061-12297-14-git-send-email-zwu.kernel@gmail.com> References: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Cc: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, david@fromorbit.com, tytso@mit.edu, cmm@us.ibm.com, wuzhy@linux.vnet.ibm.com, wenqing.lz@taobao.com To: linux-fsdevel@vger.kernel.org Return-path: Received: from e37.co.us.ibm.com ([32.97.110.158]:44918 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757944Ab2J2Edm (ORCPT ); Mon, 29 Oct 2012 00:33:42 -0400 Received: from /spool/local by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 28 Oct 2012 22:33:41 -0600 In-Reply-To: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Zhi Yong Wu The debugfs function is used to get expected dentry. Signed-off-by: Zhi Yong Wu --- fs/debugfs/inode.c | 26 ++++++++++++++++++++++++++ include/linux/debugfs.h | 9 +++++++++ 2 files changed, 35 insertions(+), 0 deletions(-) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index b607d92..c6291bc 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -354,6 +354,32 @@ exit: return dentry; } +struct dentry *debugfs_get_dentry(const char *name, + struct dentry *parent, int len) +{ + struct dentry *dentry = NULL; + int error = 0; + + error = simple_pin_fs(&debug_fs_type, &debugfs_mount, + &debugfs_mount_count); + if (error) + return NULL; + + if (!parent) + parent = debugfs_mount->mnt_root; + + mutex_lock(&parent->d_inode->i_mutex); + dentry = lookup_one_len(name, parent, strlen(name)); + if (!IS_ERR(dentry)) { + mutex_unlock(&parent->d_inode->i_mutex); + return dentry; + } + mutex_unlock(&parent->d_inode->i_mutex); + + return NULL; +} +EXPORT_SYMBOL_GPL(debugfs_get_dentry); + /** * debugfs_create_file - create a file in the debugfs filesystem * @name: a pointer to a string containing the name of the file to create. diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 66c434f..8913a4d 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -46,6 +46,9 @@ extern struct dentry *arch_debugfs_dir; extern const struct file_operations debugfs_file_operations; extern const struct inode_operations debugfs_link_operations; +struct dentry *debugfs_get_dentry(const char *name, + struct dentry *parent, int len); + struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops); @@ -103,6 +106,12 @@ bool debugfs_initialized(void); #include +static inline struct dentry *debugfs_get_dentry(const char *name, + struct dentry *parent, int len) +{ + return ERR_PTR(-ENODEV); +} + /* * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled * so users have a chance to detect if there was a real error or not. We don't -- 1.7.6.5