From abca8759df783b5f2d920fccb8abc4c75699b3c1 Mon Sep 17 00:00:00 2001 From: Roger Pau Monne Date: Tue, 4 Dec 2012 15:21:53 +0100 Subject: [PATCH] --- yaml --- r: 349565 b: refs/heads/master c: ebb351cf78ee6bf3262e6b4b6906f456c05e6d5e h: refs/heads/master i: 349563: 9e04234bcd6a4e506e188250edd016ee25f96c40 v: v3 --- [refs] | 2 +- trunk/drivers/block/xen-blkfront.c | 3 ++- trunk/include/linux/llist.h | 25 +++++++++++++++++++++++++ 3 files changed, 28 insertions(+), 2 deletions(-) diff --git a/[refs] b/[refs] index e6c5ec609c5f..159093fbfe17 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 7dc341175af5e7361af81499ea192c7b274b6357 +refs/heads/master: ebb351cf78ee6bf3262e6b4b6906f456c05e6d5e diff --git a/trunk/drivers/block/xen-blkfront.c b/trunk/drivers/block/xen-blkfront.c index 96e9b00db081..cfdb033c7107 100644 --- a/trunk/drivers/block/xen-blkfront.c +++ b/trunk/drivers/block/xen-blkfront.c @@ -792,6 +792,7 @@ static void blkif_free(struct blkfront_info *info, int suspend) { struct llist_node *all_gnts; struct grant *persistent_gnt; + struct llist_node *n; /* Prevent new requests being issued until we fix things up. */ spin_lock_irq(&info->io_lock); @@ -804,7 +805,7 @@ static void blkif_free(struct blkfront_info *info, int suspend) /* Remove all persistent grants */ if (info->persistent_gnts_c) { all_gnts = llist_del_all(&info->persistent_gnts); - llist_for_each_entry(persistent_gnt, all_gnts, node) { + llist_for_each_entry_safe(persistent_gnt, n, all_gnts, node) { gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); __free_page(pfn_to_page(persistent_gnt->pfn)); kfree(persistent_gnt); diff --git a/trunk/include/linux/llist.h b/trunk/include/linux/llist.h index a5199f6d0e82..d0ab98f73d38 100644 --- a/trunk/include/linux/llist.h +++ b/trunk/include/linux/llist.h @@ -124,6 +124,31 @@ static inline void init_llist_head(struct llist_head *list) &(pos)->member != NULL; \ (pos) = llist_entry((pos)->member.next, typeof(*(pos)), member)) +/** + * llist_for_each_entry_safe - iterate safely against remove over some entries + * of lock-less list of given type. + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as a temporary storage. + * @node: the fist entry of deleted list entries. + * @member: the name of the llist_node with the struct. + * + * In general, some entries of the lock-less list can be traversed + * safely only after being removed from list, so start with an entry + * instead of list head. This variant allows removal of entries + * as we iterate. + * + * If being used on entries deleted from lock-less list directly, the + * traverse order is from the newest to the oldest added entry. If + * you want to traverse from the oldest to the newest, you must + * reverse the order by yourself before traversing. + */ +#define llist_for_each_entry_safe(pos, n, node, member) \ + for ((pos) = llist_entry((node), typeof(*(pos)), member), \ + (n) = (pos)->member.next; \ + &(pos)->member != NULL; \ + (pos) = llist_entry(n, typeof(*(pos)), member), \ + (n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL) + /** * llist_empty - tests whether a lock-less list is empty * @head: the list to test