From: Tejun Heo Date: Wed, 13 Jun 2007 18:45:15 +0000 (+0900) Subject: sysfs: implement kobj_sysfs_assoc_lock X-Git-Tag: v2.6.23-rc1~1107^2~29 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=aecdcedaab49ca40620dc7dd70f67ee7269a66c9;p=linux-2.6-omap-h63xx.git sysfs: implement kobj_sysfs_assoc_lock kobj->dentry can go away anytime unless the user controls when the associated sysfs node is deleted. This patch implements kobj_sysfs_assoc_lock which protects kobj->dentry. This will be used to maintain kobj based API when converting sysfs to use sysfs_dirent tree instead of dentry/kobject. Note that this lock belongs to kobject/driver-model not sysfs. Once sysfs is converted to not use kobject in its interface, this can be removed from sysfs. This is in preparation of object reference simplification. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 07912269567..e9fddcc5944 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -15,6 +15,7 @@ DECLARE_RWSEM(sysfs_rename_sem); spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED; +spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; static DEFINE_IDA(sysfs_ino_ida); @@ -426,8 +427,13 @@ static void __sysfs_remove_dir(struct dentry *dentry) void sysfs_remove_dir(struct kobject * kobj) { - __sysfs_remove_dir(kobj->dentry); + struct dentry *d = kobj->dentry; + + spin_lock(&kobj_sysfs_assoc_lock); kobj->dentry = NULL; + spin_unlock(&kobj_sysfs_assoc_lock); + + __sysfs_remove_dir(d); } int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 39ab0481379..718e2e123fa 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -62,6 +62,7 @@ extern void sysfs_drop_dentry(struct sysfs_dirent *sd, struct dentry *parent); extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); extern spinlock_t sysfs_lock; +extern spinlock_t kobj_sysfs_assoc_lock; extern struct rw_semaphore sysfs_rename_sem; extern struct super_block * sysfs_sb; extern const struct file_operations sysfs_dir_operations;