Commit 7a0ad546 authored by Kees Cook's avatar Kees Cook
Browse files

pstore: Refactor pstorefs record list removal 

The "unlink" handling should perform list removal (which can also make
sure records don't get double-erased), and the "evict" handling should
be responsible only for memory freeing.

Link: https://lore.kernel.org/lkml/20200506152114.50375-8-keescook@chromium.org/


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 6248a066

fs/pstore/inode.c

+13 −6
Original line number Diff line number Diff line
@@ -177,10 +177,21 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) 
{

	struct pstore_private *p = d_inode(dentry)->i_private;

	struct pstore_record *record = p->record;

	int rc = 0;



	if (!record->psi->erase)

		return -EPERM;



	/* Make sure we can't race while removing this file. */

	mutex_lock(&records_list_lock);

	if (!list_empty(&p->list))

		list_del_init(&p->list);

	else

		rc = -ENOENT;

	mutex_unlock(&records_list_lock);

	if (rc)

		return rc;



	mutex_lock(&record->psi->read_mutex);

	record->psi->erase(record);

	mutex_unlock(&record->psi->read_mutex);
@@ -193,13 +204,8 @@ static void pstore_evict_inode(struct inode *inode) 
	struct pstore_private	*p = inode->i_private;



	clear_inode(inode);

	if (p) {

		mutex_lock(&records_list_lock);

		list_del(&p->list);

		mutex_unlock(&records_list_lock);

	free_pstore_private(p);

}

}



static const struct inode_operations pstore_dir_inode_operations = {

	.lookup		= simple_lookup,
@@ -417,6 +423,7 @@ static void pstore_kill_sb(struct super_block *sb) 
{

	kill_litter_super(sb);

	pstore_sb = NULL;

	INIT_LIST_HEAD(&records_list);

}



static struct file_system_type pstore_fs_type = {

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