Commit 105c2db2 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Fix nfs_clear_verifier_delegated() for delegated directories 



If the client returns a directory delegation, then look up all the child
dentries, and clear their 'verifier delegated' bit, unless subject to a
file delegation.

Similarly, if a file delegation is being returned, check if there is a
directory delegation before clearing a 'verifier delegated' bit.

Reported-by: default avatarChristoph Hellwig <hch@lst.de>
Fixes: 156b0948 ("NFS: Request a directory delegation on ACCESS, CREATE, and UNLINK")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 6f9bda23

fs/nfs/dir.c

+49 −8
Original line number Diff line number Diff line
@@ -1440,7 +1440,8 @@ static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf) 


	if (!dir || !nfs_verify_change_attribute(dir, verf))

		return;

	if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ, 0))

	if (NFS_PROTO(dir)->have_delegation(dir, FMODE_READ, 0) ||

	    (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ, 0)))

		nfs_set_verifier_delegated(&verf);

	dentry->d_time = verf;

}
@@ -1465,6 +1466,49 @@ void nfs_set_verifier(struct dentry *dentry, unsigned long verf) 
EXPORT_SYMBOL_GPL(nfs_set_verifier);



#if IS_ENABLED(CONFIG_NFS_V4)

static void nfs_clear_verifier_file(struct inode *inode)

{

	struct dentry *alias;

	struct inode *dir;



	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {

		spin_lock(&alias->d_lock);

		dir = d_inode_rcu(alias->d_parent);

		if (!dir ||

		    !NFS_PROTO(dir)->have_delegation(dir, FMODE_READ, 0))

			nfs_unset_verifier_delegated(&alias->d_time);

		spin_unlock(&alias->d_lock);

	}

}



static void nfs_clear_verifier_directory(struct inode *dir)

{

	struct dentry *this_parent;

	struct dentry *dentry;

	struct inode *inode;



	if (hlist_empty(&dir->i_dentry))

		return;

	this_parent =

		hlist_entry(dir->i_dentry.first, struct dentry, d_u.d_alias);



	spin_lock(&this_parent->d_lock);

	nfs_unset_verifier_delegated(&this_parent->d_time);

	dentry = d_first_child(this_parent);

	hlist_for_each_entry_from(dentry, d_sib) {

		if (unlikely(dentry->d_flags & DCACHE_DENTRY_CURSOR))

			continue;

		inode = d_inode_rcu(dentry);

		if (inode &&

		    NFS_PROTO(inode)->have_delegation(inode, FMODE_READ, 0))

			continue;

		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);

		nfs_unset_verifier_delegated(&dentry->d_time);

		spin_unlock(&dentry->d_lock);

	}

	spin_unlock(&this_parent->d_lock);

}



/**

 * nfs_clear_verifier_delegated - clear the dir verifier delegation tag

 * @inode: pointer to inode
@@ -1477,16 +1521,13 @@ EXPORT_SYMBOL_GPL(nfs_set_verifier); 
 */

void nfs_clear_verifier_delegated(struct inode *inode)

{

	struct dentry *alias;



	if (!inode)

		return;

	spin_lock(&inode->i_lock);

	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {

		spin_lock(&alias->d_lock);

		nfs_unset_verifier_delegated(&alias->d_time);

		spin_unlock(&alias->d_lock);

	}

	if (S_ISREG(inode->i_mode))

		nfs_clear_verifier_file(inode);

	else if (S_ISDIR(inode->i_mode))

		nfs_clear_verifier_directory(inode);

	spin_unlock(&inode->i_lock);

}

EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);