From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: [PATCH 04/15] sysfs: Implement __sysfs_get_dentry Date: Thu, 03 Jul 2008 18:09:04 -0700 Message-ID: References: <20080618170729.808539948@theryb.frec.bull.fr> <486706C9.9040303@gmail.com> <4869D314.5030403@gmail.com> <486A0751.9080602@gmail.com> <486AF4FA.8020805@gmail.com> <486B060C.7030607@gmail.com> <486C4515.1070007@gmail.com> <486CB051.5000507@fr.ibm.com> <486CF71F.5090405@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: (Eric W. Biederman's message of "Thu, 03 Jul 2008 18:08:02 -0700") Sender: netdev-owner@vger.kernel.org To: Greg Kroah-Hartman , Andrew Morton Cc: Tejun Heo , Daniel Lezcano , linux-kernel@vger.kernel.org, Al Viro , Linux Containers , Benjamin Thery , netdev@vger.kernel.org List-Id: containers.vger.kernel.org This function is similar but much simpler to sysfs_get_dentry returns a sysfs dentry if one curently exists. Signed-off-by: Eric W. Biederman Signed-off-by: Benjamin Thery Signed-off-by: Daniel Lezcano Acked-by: Tejun Heo --- fs/sysfs/dir.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 39 insertions(+), 0 deletions(-) diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 69c40ed..df9934a 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -764,6 +764,45 @@ void sysfs_remove_dir(struct kobject * kobj) __sysfs_remove_dir(sd); } +/** + * __sysfs_get_dentry - get dentry for the given sysfs_dirent + * @sb: superblock of the dentry to return + * @sd: sysfs_dirent of interest + * + * Get dentry for @sd. Only return a dentry if one currently + * exists. + * + * LOCKING: + * Kernel thread context (may sleep) + * + * RETURNS: + * Pointer to found dentry on success, NULL on failure. + */ +static struct dentry *__sysfs_get_dentry(struct super_block *sb, + struct sysfs_dirent *sd) +{ + struct inode *inode; + struct dentry *dentry = NULL; + + inode = ilookup5_nowait(sysfs_sb, sd->s_ino, sysfs_ilookup_test, sd); + if (inode && !(inode->i_state & I_NEW)) { + struct dentry *alias; + spin_lock(&dcache_lock); + list_for_each_entry(alias, &inode->i_dentry, d_alias) { + if (!IS_ROOT(alias) && d_unhashed(alias)) + continue; + if (alias->d_sb != sb) + continue; + dentry = alias; + dget_locked(dentry); + break; + } + spin_unlock(&dcache_lock); + } + iput(inode); + return dentry; +} + int sysfs_rename_dir(struct kobject * kobj, const char *new_name) { struct sysfs_dirent *sd = kobj->sd; -- 1.5.3.rc6.17.g1911