From htejun@gmail.com Wed Jun 13 12:27:32 2007 From: Tejun Heo Cc: Tejun Heo Subject: [PATCH 01/11] sysfs: make sysfs_drop_dentry() access inodes using ilookup() Date: Thu, 14 Jun 2007 04:27:21 +0900 Message-Id: <11817628414141-git-send-email-htejun@gmail.com> To: greg@kroah.com, dmitry.torokhov@gmail.com, cornelia.huck@de.ibm.com, oneukum@suse.de, rpurdie@rpsys.net, stern@rowland.harvard.edu, maneesh@in.ibm.com, linux-kernel@vger.kernel.org, htejun@gmail.com From: Tejun Heo sysfs_drop_dentry() used to go through sd->s_dentry and sd->s_parent->s_dentry to access the inodes. This is incorrect because inode can be cached without dentry. This patch makes sysfs_drop_dentry() access inodes using ilookup() on sd->s_ino. This is both correct and simpler. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 63 ++++++++++++++++++++++++------------------------------- 1 file changed, 28 insertions(+), 35 deletions(-) --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -219,9 +219,9 @@ void sysfs_instantiate(struct dentry *de */ void sysfs_drop_dentry(struct sysfs_dirent *sd) { - struct dentry *dentry = NULL, *parent = NULL; - struct inode *dir; + struct dentry *dentry = NULL; struct timespec curtime; + struct inode *inode; /* We're not holding a reference to ->s_dentry dentry but the * field will stay valid as long as sysfs_lock is held. @@ -229,19 +229,9 @@ void sysfs_drop_dentry(struct sysfs_dire spin_lock(&sysfs_lock); spin_lock(&dcache_lock); + /* drop dentry if it's there and dput() didn't kill it yet */ if (sd->s_dentry && sd->s_dentry->d_inode) { - /* get dentry if it's there and dput() didn't kill it yet */ dentry = dget_locked(sd->s_dentry); - parent = dentry->d_parent; - } else if (sd->s_parent->s_dentry->d_inode) { - /* We need to update the parent even if dentry for the - * victim itself doesn't exist. - */ - parent = dget_locked(sd->s_parent->s_dentry); - } - - /* drop */ - if (dentry) { spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); @@ -250,36 +240,39 @@ void sysfs_drop_dentry(struct sysfs_dire spin_unlock(&dcache_lock); spin_unlock(&sysfs_lock); - /* nothing to do if the parent isn't in dcache */ - if (!parent) - return; + dput(dentry); + /* XXX: unpin if directory, this will go away soon */ + if (sd->s_type & SYSFS_DIR) + dput(dentry); /* adjust nlink and update timestamp */ - dir = parent->d_inode; - mutex_lock(&dir->i_mutex); - curtime = CURRENT_TIME; - dir->i_ctime = dir->i_mtime = curtime; + inode = ilookup(sysfs_sb, sd->s_ino); + if (inode) { + mutex_lock(&inode->i_mutex); + + inode->i_ctime = curtime; + drop_nlink(inode); + if (sd->s_type & SYSFS_DIR) + drop_nlink(inode); - if (dentry) { - dentry->d_inode->i_ctime = curtime; - drop_nlink(dentry->d_inode); - if (sd->s_type & SYSFS_DIR) { - drop_nlink(dentry->d_inode); - drop_nlink(dir); - /* XXX: unpin if directory, this will go away soon */ - dput(dentry); - } + mutex_unlock(&inode->i_mutex); + iput(inode); } - mutex_unlock(&dir->i_mutex); + /* adjust nlink and udpate timestamp of the parent */ + inode = ilookup(sysfs_sb, sd->s_parent->s_ino); + if (inode) { + mutex_lock(&inode->i_mutex); + + inode->i_ctime = inode->i_mtime = curtime; + if (sd->s_type & SYSFS_DIR) + drop_nlink(inode); - /* bye bye */ - if (dentry) - dput(dentry); - else - dput(parent); + mutex_unlock(&inode->i_mutex); + iput(inode); + } } int sysfs_hash_and_remove(struct dentry * dir, const char * name)