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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-07 08:38:33 +1100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-07 08:38:33 +1100
commit2110cf029a67237db572299bb51e0de9e3e3d4dd (patch)
tree6837ff139a807037f06952c3eb72c3e350bc05c8 /include
parent1589a3e7777631ff56dd58cd7dcdf275185e62b5 (diff)
parent1383923d1985cef2bceb8128094fbe5e05de7435 (diff)
downloadlinux-2110cf029a67237db572299bb51e0de9e3e3d4dd.tar.gz
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe: "I've got a few bits pending for 3.8 final, that I better get sent out. It's all been sitting for a while, I consider it safe. It contains: - Two bug fixes for mtip32xx, fixing a driver hang and a crash. - A few-liner protocol error fix for drbd. - A few fixes for the xen block front/back driver, fixing a potential data corruption issue. - A race fix for disk_clear_events(), causing spurious warnings. Out of the Chrome OS base. - A deadlock fix for disk_clear_events(), moving it to the a unfreezable workqueue. Also from the Chrome OS base." * 'for-linus' of git://git.kernel.dk/linux-block: drbd: fix potential protocol error and resulting disconnect/reconnect mtip32xx: fix for crash when the device surprise removed during rebuild mtip32xx: fix for driver hang after a command timeout block: prevent race/cleanup block: remove deadlock in disk_clear_events xen-blkfront: handle bvecs with partial data llist/xen-blkfront: implement safe version of llist_for_each_entry xen-blkback: implement safe iterator for the list of persistent grants
Diffstat (limited to 'include')
-rw-r--r--include/linux/llist.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/llist.h b/include/linux/llist.h
index a5199f6d0e8..d0ab98f73d3 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -125,6 +125,31 @@ 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
*