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Commit f5e1c1c1 authored by Al Viro's avatar Al Viro
Browse files

split do_revalidate() into RCU and non-RCU cases 



fixing oopsen in lookup_one_len()

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 24643087

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))