sysfs: implement kobj_sysfs_assoc_lock (aecdceda) · Commits · 戴 / test

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 <htejun@gmail.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@suse.de>

fs/sysfs/dir.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -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,

fs/sysfs/sysfs.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;

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