Commit 357f8e65 authored by Nick Piggin's avatar Nick Piggin
Browse files

fs: dcache reduce dcache_inode_lock 



dcache_inode_lock can be avoided in d_delete() and d_materialise_unique()
in cases where it is not required.

Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
parent 89ad485f

fs/dcache.c

+12 −12
Original line number Diff line number Diff line
@@ -1828,10 +1828,15 @@ void d_delete(struct dentry * dentry) 
	/*

	 * Are we the only user?

	 */

	spin_lock(&dcache_inode_lock);

again:

	spin_lock(&dentry->d_lock);

	isdir = S_ISDIR(dentry->d_inode->i_mode);

	if (dentry->d_count == 1) {

		if (!spin_trylock(&dcache_inode_lock)) {

			spin_unlock(&dentry->d_lock);

			cpu_relax();

			goto again;

		}

		dentry->d_flags &= ~DCACHE_CANT_MOUNT;

		dentry_iput(dentry);

		fsnotify_nameremove(dentry, isdir);
@@ -1842,7 +1847,6 @@ void d_delete(struct dentry * dentry) 
		__d_drop(dentry);



	spin_unlock(&dentry->d_lock);

	spin_unlock(&dcache_inode_lock);



	fsnotify_nameremove(dentry, isdir);

}
@@ -2164,14 +2168,15 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) 


	BUG_ON(!d_unhashed(dentry));



	spin_lock(&dcache_inode_lock);



	if (!inode) {

		actual = dentry;

		__d_instantiate(dentry, NULL);

		goto found_lock;

		d_rehash(actual);

		goto out_nolock;

	}



	spin_lock(&dcache_inode_lock);



	if (S_ISDIR(inode->i_mode)) {

		struct dentry *alias;
@@ -2198,10 +2203,9 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) 
	actual = __d_instantiate_unique(dentry, inode);

	if (!actual)

		actual = dentry;

	else if (unlikely(!d_unhashed(actual)))

		goto shouldnt_be_hashed;

	else

		BUG_ON(!d_unhashed(actual));



found_lock:

	spin_lock(&actual->d_lock);

found:

	spin_lock(&dcache_hash_lock);
@@ -2217,10 +2221,6 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) 


	iput(inode);

	return actual;



shouldnt_be_hashed:

	spin_unlock(&dcache_inode_lock);

	BUG();

}

EXPORT_SYMBOL_GPL(d_materialise_unique);