From 80e14deab672c43e0ccde437cbf076698b11218e Mon Sep 17 00:00:00 2001 From: Josh Durgin Date: Wed, 12 Jun 2013 19:15:06 -0700 Subject: rbd: use the correct length for format 2 object names commit 3a96d5cd7bdce45d5dded75c3a62d4fb98050280 upstream. [Backported for 3.9-stable. 'kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO)' was changed as 'kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO)' in 78c2a44 since 3.10-rc1, and 78c2a44 is relied on a big patchset, so restore it as 3.9 did.] 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. Reported-by: Chris Dunlop Signed-off-by: Josh Durgin Reviewed-by: Sage Weil Reviewed-by: Lingzhu Xiang Signed-off-by: Zhouping Liu Signed-off-by: Greg Kroah-Hartman --- 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 fe333e4b731e..c2b1427e3468 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -833,12 +833,16 @@ static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) char *name; u64 segment; int ret; + char *name_format; name = kmalloc(MAX_OBJ_NAME_SIZE + 1, 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", -- cgit v1.2.3