Commit 3a96d5cd authored Jun 12, 2013 by Josh Durgin Committed by Sage Weil Jun 13, 2013

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 <chris@onthe.net.au>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

parent 3abef3b3

drivers/block/rbd.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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",

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