From 3a96d5cd7bdce45d5dded75c3a62d4fb98050280 Mon Sep 17 00:00:00 2001 From: Josh Durgin Date: Wed, 12 Jun 2013 19:15:06 -0700 Subject: [PATCH] rbd: use the correct length for format 2 object names Format 2 objects use 16 characters for the object name suffix to be able to express the full 64-bit range of object numbers. Format 1 images only use 12 characters for this. Using 12-character names for format 2 caused userspace and kernel rbd clients to read differently named objects, which made an image written by one client look empty to the other client. CC: stable@vger.kernel.org # 3.9+ Reported-by: Chris Dunlop Signed-off-by: Josh Durgin Reviewed-by: Sage Weil --- drivers/block/rbd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 3a897a5..cc7c60e 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1038,12 +1038,16 @@ static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) char *name; u64 segment; int ret; + char *name_format; name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO); if (!name) return NULL; segment = offset >> rbd_dev->header.obj_order; - ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx", + name_format = "%s.%012llx"; + if (rbd_dev->image_format == 2) + name_format = "%s.%016llx"; + ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, name_format, rbd_dev->header.object_prefix, segment); if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) { pr_err("error formatting segment name for #%llu (%d)\n", -- 2.7.4