split do_revalidate() into RCU and non-RCU cases (f5e1c1c1) · Commits · 戴 / test

fs/namei.c

+30 −17

Original line number	Diff line number	Diff line
		@@ -592,12 +592,10 @@ static int d_revalidate(struct dentry dentry, struct nameidata nd)
		return status;
		}

		static inline struct dentry *
		static struct dentry *
		do_revalidate(struct dentry dentry, struct nameidata nd)
		{
		int status;

		status = d_revalidate(dentry, nd);
		int status = d_revalidate(dentry, nd);
		if (unlikely(status <= 0)) {
		/*
		* The dentry failed validation.
		@@ -606,21 +604,36 @@ do_revalidate(struct dentry dentry, struct nameidata nd)
		* to return a fail status.
		*/
		if (status < 0) {
		/* If we're in rcu-walk, we don't have a ref */
		if (!(nd->flags & LOOKUP_RCU))
		dput(dentry);
		dentry = ERR_PTR(status);
		} else if (!d_invalidate(dentry)) {
		dput(dentry);
		dentry = NULL;
		}
		}
		return dentry;
		}

		} else {
		static inline struct dentry *
		do_revalidate_rcu(struct dentry dentry, struct nameidata nd)
		{
		int status = dentry->d_op->d_revalidate(dentry, nd);
		if (likely(status > 0))
		return dentry;
		if (status == -ECHILD) {
		if (nameidata_dentry_drop_rcu(nd, dentry))
		return ERR_PTR(-ECHILD);
		return do_revalidate(dentry, nd);
		}
		if (status < 0)
		return ERR_PTR(status);
		/* Don't d_invalidate in rcu-walk mode */
		if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
		if (nameidata_dentry_drop_rcu(nd, dentry))
		return ERR_PTR(-ECHILD);
		if (!d_invalidate(dentry)) {
		dput(dentry);
		dentry = NULL;
		}
		}
		}
		return dentry;
		}

		@@ -1260,7 +1273,7 @@ static int do_lookup(struct nameidata nd, struct qstr name,

		nd->seq = seq;
		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
		dentry = do_revalidate(dentry, nd);
		dentry = do_revalidate_rcu(dentry, nd);
		if (!dentry)
		goto need_lookup;
		if (IS_ERR(dentry))

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