Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs (d6dd6431) · Commits · 戴 / test

fs/dcache.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -358,13 +358,10 @@ static void dentry_unlink_inode(struct dentry * dentry)
		__releases(dentry->d_inode->i_lock)
		{
		struct inode *inode = dentry->d_inode;
		bool hashed = !d_unhashed(dentry);

		if (hashed)
		raw_write_seqcount_begin(&dentry->d_seq);
		__d_clear_type_and_inode(dentry);
		hlist_del_init(&dentry->d_u.d_alias);
		if (hashed)
		raw_write_seqcount_end(&dentry->d_seq);
		spin_unlock(&dentry->d_lock);
		spin_unlock(&inode->i_lock);
		@@ -1932,11 +1929,13 @@ struct dentry d_make_root(struct inode root_inode)

		if (root_inode) {
		res = d_alloc_anon(root_inode->i_sb);
		if (res)
		if (res) {
		res->d_flags \|= DCACHE_RCUACCESS;
		d_instantiate(res, root_inode);
		else
		} else {
		iput(root_inode);
		}
		}
		return res;
		}
		EXPORT_SYMBOL(d_make_root);

+26 −2

Original line number	Diff line number	Diff line
		@@ -659,12 +659,21 @@ int __legitimize_mnt(struct vfsmount *bastard, unsigned seq)
		return 0;
		mnt = real_mount(bastard);
		mnt_add_count(mnt, 1);
		smp_mb(); // see mntput_no_expire()
		if (likely(!read_seqretry(&mount_lock, seq)))
		return 0;
		if (bastard->mnt_flags & MNT_SYNC_UMOUNT) {
		mnt_add_count(mnt, -1);
		return 1;
		}
		lock_mount_hash();
		if (unlikely(bastard->mnt_flags & MNT_DOOMED)) {
		mnt_add_count(mnt, -1);
		unlock_mount_hash();
		return 1;
		}
		unlock_mount_hash();
		/* caller will mntput() */
		return -1;
		}

		@@ -1195,12 +1204,27 @@ static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput);
		static void mntput_no_expire(struct mount *mnt)
		{
		rcu_read_lock();
		if (likely(READ_ONCE(mnt->mnt_ns))) {
		/*
		* Since we don't do lock_mount_hash() here,
		* ->mnt_ns can change under us. However, if it's
		* non-NULL, then there's a reference that won't
		* be dropped until after an RCU delay done after
		* turning ->mnt_ns NULL. So if we observe it
		* non-NULL under rcu_read_lock(), the reference
		* we are dropping is not the final one.
		*/
		mnt_add_count(mnt, -1);
		if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */
		rcu_read_unlock();
		return;
		}
		lock_mount_hash();
		/*
		* make sure that if __legitimize_mnt() has not seen us grab
		* mount_lock, we'll see their refcount increment here.
		*/
		smp_mb();
		mnt_add_count(mnt, -1);
		if (mnt_get_count(mnt)) {
		rcu_read_unlock();
		unlock_mount_hash();