Commit 03507db6 authored Aug 27, 2013 by Josh Durgin Committed by Sage Weil Sep 03, 2013

rbd: fix buffer size for writes to images with snapshots

rbd_osd_req_create() needs to know the snapshot context size to create
a buffer large enough to send it with the message front. It gets this
from the img_request, which was not set for the obj_request yet. This
resulted in trying to write past the end of the front payload, hitting
this BUG:

libceph: BUG_ON(p > msg->front.iov_base + msg->front.iov_len);

Fix this by associating the obj_request with its img_request
immediately after it's created, before the osd request is created.

Fixes: http://tracker.ceph.com/issues/5760


Suggested-by: Alex Elder <alex.elder@linaro.org>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <alex.elder@linaro.org>

parent 9542cf0b

drivers/block/rbd.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -2203,6 +2203,11 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
		rbd_segment_name_free(object_name);
		if (!obj_request)
		goto out_unwind;
		/*
		* set obj_request->img_request before creating the
		* osd_request so that it gets the right snapc
		*/
		rbd_img_obj_request_add(img_request, obj_request);

		if (type == OBJ_REQUEST_BIO) {
		unsigned int clone_size;
		@@ -2244,11 +2249,6 @@ 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

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