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Subject[PATCH] xen-blkfront: drop the use of llist_for_each_entry_safe
Date
Replace llist_for_each_entry_safe with a while loop and
llist_del_first.

llist_for_each_entry_safe can trigger a bug in GCC 4.1, so it's best
to remove it and use a while loop and llist_del_first (which is
already in llist.h).

Since xen-blkfront is the only user of the llist_for_each_entry_safe
macro remove it from llist.h.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/block/xen-blkfront.c | 5 ++---
include/linux/llist.h | 25 -------------------------
2 files changed, 2 insertions(+), 28 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 11043c1..c325062 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -790,7 +790,6 @@ static void blkif_restart_queue(struct work_struct *work)

static void blkif_free(struct blkfront_info *info, int suspend)
{
- struct llist_node *all_gnts;
struct grant *persistent_gnt;
struct llist_node *n;

@@ -804,8 +803,8 @@ 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_safe(persistent_gnt, n, all_gnts, node) {
+ while ((n = llist_del_first(&info->persistent_gnts)) != NULL) {
+ persistent_gnt = llist_entry(n, struct grant, node);
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
__free_page(pfn_to_page(persistent_gnt->pfn));
kfree(persistent_gnt);
diff --git a/include/linux/llist.h b/include/linux/llist.h
index d0ab98f..a5199f6 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -125,31 +125,6 @@ static inline void init_llist_head(struct llist_head *list)
(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
*
--
1.7.7.5 (Apple Git-26)
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