Commit b2c042cc authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/scsiback: don't call scsiback_free_translation_entry() under lock 



scsiback_free_translation_entry() shouldn't be called under spinlock,
as it can sleep.

This requires to split removing a translation entry from the v2p list
from actually calling kref_put() for the entry.

Reported-by: default avatarDan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20230328084602.20729-1-jgross@suse.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent fae65ef3

drivers/xen/xen-scsiback.c

+14 −13
Original line number Diff line number Diff line
@@ -1010,12 +1010,6 @@ static int scsiback_add_translation_entry(struct vscsibk_info *info, 
	return err;

}



static void __scsiback_del_translation_entry(struct v2p_entry *entry)

{

	list_del(&entry->l);

	kref_put(&entry->kref, scsiback_free_translation_entry);

}



/*

  Delete the translation entry specified

*/
@@ -1024,18 +1018,20 @@ static int scsiback_del_translation_entry(struct vscsibk_info *info, 
{

	struct v2p_entry *entry;

	unsigned long flags;

	int ret = 0;



	spin_lock_irqsave(&info->v2p_lock, flags);

	/* Find out the translation entry specified */

	entry = scsiback_chk_translation_entry(info, v);

	if (entry)

		__scsiback_del_translation_entry(entry);

	else

		ret = -ENOENT;

		list_del(&entry->l);



	spin_unlock_irqrestore(&info->v2p_lock, flags);

	return ret;



	if (!entry)

		return -ENOENT;



	kref_put(&entry->kref, scsiback_free_translation_entry);

	return 0;

}



static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
@@ -1239,14 +1235,19 @@ static void scsiback_release_translation_entry(struct vscsibk_info *info) 
{

	struct v2p_entry *entry, *tmp;

	struct list_head *head = &(info->v2p_entry_lists);

	struct list_head tmp_list;

	unsigned long flags;



	spin_lock_irqsave(&info->v2p_lock, flags);



	list_for_each_entry_safe(entry, tmp, head, l)

		__scsiback_del_translation_entry(entry);

	list_cut_before(&tmp_list, head, head);



	spin_unlock_irqrestore(&info->v2p_lock, flags);



	list_for_each_entry_safe(entry, tmp, &tmp_list, l) {

		list_del(&entry->l);

		kref_put(&entry->kref, scsiback_free_translation_entry);

	}

}



static void scsiback_remove(struct xenbus_device *dev)