Commit d2d1f17a authored Jun 26, 2013 by Josh Durgin Committed by Sage Weil Jun 27, 2013

rbd: send snapshot context with writes

Sending the right snapshot context with each write is required for
snapshots to work. Due to the ordering of calls, the snapshot context
is never set for any requests. This causes writes to the current
version of the image to be reflected in all snapshots, which are
supposed to be read-only.

This happens because rbd_osd_req_format_write() sets the snapshot
context based on obj_request->img_request. At this point, however,
obj_request->img_request has not been set yet, to the snapshot context
is set to NULL. Fix this by moving rbd_img_obj_request_add(), which
sets obj_request->img_request, before the osd request formatting
calls.

This resolves:
    http://tracker.ceph.com/issues/5465



Reported-by: Karol Jurak <karol.jurak@gmail.com>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

parent 1617e40c

drivers/block/rbd.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -2254,13 +2254,17 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
		obj_request->pages, length,
		offset & ~PAGE_MASK, false, false);

		/*
		* set obj_request->img_request before formatting
		* the osd_request so that it gets the right snapc
		*/
		rbd_img_obj_request_add(img_request, obj_request);
		if (write_request)
		rbd_osd_req_format_write(obj_request);
		else
		rbd_osd_req_format_read(obj_request);

		obj_request->img_offset = img_offset;
		rbd_img_obj_request_add(img_request, obj_request);

		img_offset += length;
		resid -= length;

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