linux-kernel - [PATCH 04/15] sysfs: Implement __sysfs_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <m1hcb6ihfz.fsf_-_@frodo.ebiederm.org>
Date:	Thu, 03 Jul 2008 18:09:04 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Greg Kroah-Hartman <gregkh@...e.de>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Tejun Heo <htejun@...il.com>, Daniel Lezcano <dlezcano@...ibm.com>,
	linux-kernel@...r.kernel.org, Al Viro <viro@....linux.org.uk>,
	Linux Containers <containers@...ts.osdl.org>,
	Benjamin Thery <benjamin.thery@...l.net>,
	<netdev@...r.kernel.org>
Subject: [PATCH 04/15] sysfs: Implement __sysfs_get_dentry


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 <ebiederm@...ssion.com>
Signed-off-by: Benjamin Thery <benjamin.thery@...l.net>
Signed-off-by: Daniel Lezcano <dlezcano@...ibm.com>
Acked-by: Tejun Heo <tj@...nel.org>
---
 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/