Messages in this thread Patch in this message | | | From | Jakob Koschel <> | Subject | [PATCH 1/2] dm snapshot: remove usage of list iterator for list_add() after the loop body | Date | Fri, 1 Apr 2022 00:02:35 +0200 |
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In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1].
Before, the code implicitly used the head when no element was found when using &pos->list. Since the new variable is only set if an element was found, the list_add() is performed within the loop and only done after the loop if it is done on the list head directly.
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> --- drivers/md/dm-snap.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 0d336b5ec571..23386a6e67e7 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -528,13 +528,17 @@ static int __validate_exception_handover(struct dm_snapshot *snap) static void __insert_snapshot(struct origin *o, struct dm_snapshot *s) { - struct dm_snapshot *l; + struct dm_snapshot *l = NULL, *iter; /* Sort the list according to chunk size, largest-first smallest-last */ - list_for_each_entry(l, &o->snapshots, list) - if (l->store->chunk_size < s->store->chunk_size) + list_for_each_entry(iter, &o->snapshots, list) + if (iter->store->chunk_size < s->store->chunk_size) { + l = iter; + list_add_tail(&s->list, &iter->list); break; - list_add_tail(&s->list, &l->list); + } + if (!l) + list_add_tail(&s->list, &o->snapshots); } /* base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275 -- 2.25.1
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