Commit f9c34674 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Miklos Szeredi
Browse files

vfs: factor out helpers d_instantiate_anon() and d_alloc_anon() 



Those helpers are going to be used by overlayfs to implement
NFS export decode.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent c62520a8

fs/dcache.c

+56 −31
Original line number Diff line number Diff line
@@ -1699,9 +1699,15 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) 
}

EXPORT_SYMBOL(d_alloc);



struct dentry *d_alloc_anon(struct super_block *sb)

{

	return __d_alloc(sb, NULL);

}

EXPORT_SYMBOL(d_alloc_anon);



struct dentry *d_alloc_cursor(struct dentry * parent)

{

	struct dentry *dentry = __d_alloc(parent->d_sb, NULL);

	struct dentry *dentry = d_alloc_anon(parent->d_sb);

	if (dentry) {

		dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR;

		dentry->d_parent = dget(parent);
@@ -1887,7 +1893,7 @@ struct dentry *d_make_root(struct inode *root_inode) 
	struct dentry *res = NULL;



	if (root_inode) {

		res = __d_alloc(root_inode->i_sb, NULL);

		res = d_alloc_anon(root_inode->i_sb);

		if (res)

			d_instantiate(res, root_inode);

		else
@@ -1926,33 +1932,19 @@ struct dentry *d_find_any_alias(struct inode *inode) 
}

EXPORT_SYMBOL(d_find_any_alias);



static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)

static struct dentry *__d_instantiate_anon(struct dentry *dentry,

					   struct inode *inode,

					   bool disconnected)

{

	struct dentry *tmp;

	struct dentry *res;

	unsigned add_flags;



	if (!inode)

		return ERR_PTR(-ESTALE);

	if (IS_ERR(inode))

		return ERR_CAST(inode);



	res = d_find_any_alias(inode);

	if (res)

		goto out_iput;



	tmp = __d_alloc(inode->i_sb, NULL);

	if (!tmp) {

		res = ERR_PTR(-ENOMEM);

		goto out_iput;

	}



	security_d_instantiate(tmp, inode);

	security_d_instantiate(dentry, inode);

	spin_lock(&inode->i_lock);

	res = __d_find_any_alias(inode);

	if (res) {

		spin_unlock(&inode->i_lock);

		dput(tmp);

		dput(dentry);

		goto out_iput;

	}
@@ -1962,16 +1954,49 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) 
	if (disconnected)

		add_flags |= DCACHE_DISCONNECTED;



	spin_lock(&tmp->d_lock);

	__d_set_inode_and_type(tmp, inode, add_flags);

	hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry);

	hlist_bl_lock(&tmp->d_sb->s_anon);

	hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);

	hlist_bl_unlock(&tmp->d_sb->s_anon);

	spin_unlock(&tmp->d_lock);

	spin_lock(&dentry->d_lock);

	__d_set_inode_and_type(dentry, inode, add_flags);

	hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);

	hlist_bl_lock(&dentry->d_sb->s_anon);

	hlist_bl_add_head(&dentry->d_hash, &dentry->d_sb->s_anon);

	hlist_bl_unlock(&dentry->d_sb->s_anon);

	spin_unlock(&dentry->d_lock);

	spin_unlock(&inode->i_lock);



	return tmp;

	return dentry;



 out_iput:

	iput(inode);

	return res;

}



struct dentry *d_instantiate_anon(struct dentry *dentry, struct inode *inode)

{

	return __d_instantiate_anon(dentry, inode, true);

}

EXPORT_SYMBOL(d_instantiate_anon);



static struct dentry *__d_obtain_alias(struct inode *inode, bool disconnected)

{

	struct dentry *tmp;

	struct dentry *res;



	if (!inode)

		return ERR_PTR(-ESTALE);

	if (IS_ERR(inode))

		return ERR_CAST(inode);



	res = d_find_any_alias(inode);

	if (res)

		goto out_iput;



	tmp = d_alloc_anon(inode->i_sb);

	if (!tmp) {

		res = ERR_PTR(-ENOMEM);

		goto out_iput;

	}



	return __d_instantiate_anon(tmp, inode, disconnected);



out_iput:

	iput(inode);
@@ -1998,7 +2023,7 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) 
 */

struct dentry *d_obtain_alias(struct inode *inode)

{

	return __d_obtain_alias(inode, 1);

	return __d_obtain_alias(inode, true);

}

EXPORT_SYMBOL(d_obtain_alias);
@@ -2019,7 +2044,7 @@ EXPORT_SYMBOL(d_obtain_alias); 
 */

struct dentry *d_obtain_root(struct inode *inode)

{

	return __d_obtain_alias(inode, 0);

	return __d_obtain_alias(inode, false);

}

EXPORT_SYMBOL(d_obtain_root);

include/linux/dcache.h

+2 −0
Original line number Diff line number Diff line
@@ -227,6 +227,7 @@ extern seqlock_t rename_lock; 
 */

extern void d_instantiate(struct dentry *, struct inode *);

extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);

extern struct dentry * d_instantiate_anon(struct dentry *, struct inode *);

extern int d_instantiate_no_diralias(struct dentry *, struct inode *);

extern void __d_drop(struct dentry *dentry);

extern void d_drop(struct dentry *dentry);
@@ -235,6 +236,7 @@ extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op 


/* allocate/de-allocate */

extern struct dentry * d_alloc(struct dentry *, const struct qstr *);

extern struct dentry * d_alloc_anon(struct super_block *);

extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);

extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,

					wait_queue_head_t *);