Commit 8016ab9e authored by NeilBrown's avatar NeilBrown Committed by Greg Kroah-Hartman
Browse files

staging: lustre: llite: refine ll_find_alias based on d_exact_alias 



The task of ll_find_alias() is now very similar to d_exact_alias().
We cannot use that function directly, but we can copy much of
the structure so that the similarities and differences are more
obvious.
Examining d_exact_alias() shows that the d_lock spinlock does not
need to be held in ll_find_alias as much as it currently is.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7e08e9a8

drivers/staging/lustre/lustre/llite/namei.c

+20 −10
Original line number Diff line number Diff line
@@ -381,6 +381,10 @@ void ll_i2gids(__u32 *suppgids, struct inode *i1, struct inode *i2) 


/*

 * Try to reuse unhashed or invalidated dentries.

 * This is very similar to d_exact_alias(), and any changes in one should be

 * considered for inclusion in the other.  The differences are that we don't

 * need an unhashed alias, and we don't want d_compare to be used for

 * comparison.

 */

static struct dentry *ll_find_alias(struct inode *inode, struct dentry *dentry)

{
@@ -392,20 +396,26 @@ static struct dentry *ll_find_alias(struct inode *inode, struct dentry *dentry) 
	spin_lock(&inode->i_lock);

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

		LASSERT(alias != dentry);

		/*

		 * Don't need alias->d_lock here, because aliases with

		 * d_parent == entry->d_parent are not subject to name or

		 * parent changes, because the parent inode i_mutex is held.

		 */



		spin_lock(&alias->d_lock);

		if (alias->d_parent == dentry->d_parent	     &&

		    alias->d_name.hash == dentry->d_name.hash       &&

		    alias->d_name.len == dentry->d_name.len	 &&

		if (alias->d_parent != dentry->d_parent)

			continue;

		if (alias->d_name.hash != dentry->d_name.hash)

			continue;

		if (alias->d_name.len != dentry->d_name.len ||

		    memcmp(alias->d_name.name, dentry->d_name.name,

			   dentry->d_name.len) == 0) {

			   dentry->d_name.len) != 0)

			continue;

		spin_lock(&alias->d_lock);

		dget_dlock(alias);

		spin_unlock(&alias->d_lock);

		spin_unlock(&inode->i_lock);

		return alias;

	}

		spin_unlock(&alias->d_lock);

	}

	spin_unlock(&inode->i_lock);



	return NULL;

CRA Git | Maintained and supported by SUSTech CRA and CCSE