From: ebiederm@xmission.com (Eric W. Biederman)
To: Greg Kroah-Hartman <gregkh@suse.de>, Greg KH <greg@kroah.com>
Cc: Tejun Heo <htejun@gmail.com>,
Linux Containers <containers@lists.osdl.org>,
<netdev@vger.kernel.org>,
cornelia.huck@de.ibm.com, stern@rowland.harvard.edu,
kay.sievers@vrfy.org, <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
David Miller <davem@davemloft.net>
Subject: [PATCH 04/10] sysfs: Implement __sysfs_get_dentry
Date: Sat, 01 Dec 2007 02:18:55 -0700 [thread overview]
Message-ID: <m1odda7oxs.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <m1sl2m7p1c.fsf_-_@ebiederm.dsl.xmission.com> (Eric W. Biederman's message of "Sat, 01 Dec 2007 02:16:47 -0700")
This function is similar but much simpler to sysfs_get_dentry
returns a sysfs dentry if one curently exists.
This requires less locking the sysfs_get_dentry and which
makes it preferable in some contexts.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
fs/sysfs/dir.c | 38 ++++++++++++++++++++++++++++++++++++++
1 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index cff2b12..3ec9040 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -764,6 +764,44 @@ 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
next prev parent reply other threads:[~2007-12-01 9:21 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-01 9:06 [PATCH 0/10] sysfs network namespace support Eric W. Biederman
2007-12-01 9:12 ` [PATCH 01/10] sysfs: Make sysfs_mount static again Eric W. Biederman
2007-12-01 9:13 ` [PATCH 02/10] sysfs: Support for preventing unmounts Eric W. Biederman
2007-12-01 9:16 ` [PATCH 03/10] sysfs: sysfs_get_dentry add a sb parameter Eric W. Biederman
2007-12-01 9:18 ` Eric W. Biederman [this message]
2007-12-01 9:23 ` [PATCH 05/10] sysfs: Rename Support multiple superblocks Eric W. Biederman
2007-12-01 9:25 ` [PATCH 06/10] sysfs: sysfs_chmod_file handle " Eric W. Biederman
2007-12-01 9:28 ` [PATCH 07/10] sysfs: Implement sysfs tagged directory support Eric W. Biederman
2007-12-01 9:30 ` [PATCH 08/10] sysfs: Implement sysfs_delete_link and sysfs_rename_link Eric W. Biederman
2007-12-01 9:33 ` [PATCH 09/10] driver core: Implement tagged directory support for device classes Eric W. Biederman
2007-12-01 9:35 ` [PATCH 10/10] net: Enable tagging for net_class directories in sysfs Eric W. Biederman
2007-12-01 13:10 ` namespace support requires network modules to say "GPL" Mark Lord
2007-12-01 13:13 ` Mark Lord
2007-12-01 19:17 ` Stephen Hemminger
2007-12-01 19:23 ` Alan Cox
2007-12-01 19:38 ` Stephen Hemminger
2007-12-01 19:45 ` Alan Cox
2007-12-01 20:13 ` Eric W. Biederman
2007-12-01 20:21 ` Mark Lord
2007-12-01 20:29 ` Arjan van de Ven
2007-12-01 22:12 ` Mark Lord
2007-12-01 23:13 ` Eric W. Biederman
2007-12-01 23:24 ` Jiri Slaby
2007-12-02 1:14 ` Eric W. Biederman
2007-12-01 23:51 ` Mark Lord
2007-12-02 1:08 ` Eric W. Biederman
2007-12-01 20:52 ` Eric W. Biederman
2007-12-01 22:13 ` Mark Lord
2007-12-03 0:02 ` David Schwartz
2007-12-03 0:14 ` Alan Cox
2007-12-01 19:54 ` Eric W. Biederman
2007-12-02 0:30 ` Stephen Hemminger
2007-12-02 2:02 ` Eric W. Biederman
2007-12-02 3:34 ` Mark Lord
2007-12-02 4:23 ` Stephen Hemminger
2007-12-02 19:28 ` Ben Greear
2007-12-02 20:03 ` Patrick McHardy
2007-12-02 20:43 ` Adrian Bunk
2007-12-02 21:59 ` Patrick McHardy
2007-12-03 1:14 ` Adrian Bunk
2007-12-03 8:33 ` Denis V. Lunev
2007-12-03 17:35 ` Eric W. Biederman
2007-12-03 18:19 ` Ben Greear
2007-12-03 18:57 ` Daniel Lezcano
2007-12-04 15:19 ` Daniel Lezcano
2007-12-04 18:03 ` Eric W. Biederman
2007-12-04 18:44 ` Ben Greear
2007-12-04 19:17 ` Eric W. Biederman
2007-12-04 19:35 ` Ben Greear
2007-12-04 20:09 ` Eric W. Biederman
2007-12-05 6:14 ` David Miller
2007-12-05 6:01 ` David Miller
2007-12-04 17:59 ` Eric W. Biederman
2007-12-04 18:57 ` Ben Greear
2007-12-04 20:01 ` Eric W. Biederman
2007-12-05 6:07 ` David Miller
2007-12-03 8:24 ` Romano Giannetti
2007-12-03 15:34 ` Arjan van de Ven
2007-12-03 18:03 ` Eric W. Biederman
2007-12-03 18:13 ` David Miller
2007-12-02 13:51 ` Alan Cox
2007-12-02 19:56 ` Valdis.Kletnieks
2007-12-21 3:07 ` [PATCH 0/10] sysfs network namespace support Greg KH
2007-12-21 13:04 ` Eric W. Biederman
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