From bbea1c1a31b1128d34b2b5b4f28276969cce14e9 Mon Sep 17 00:00:00 2001
From: Alex Elder <elder@inktank.com>
Date: Mon, 6 May 2013 17:40:33 -0500
Subject: [PATCH] rbd: re-submit write request for flattened clone
Add code to rbd_img_parent_read_full_callback() to detect when a
clone's parent image has disappeared, and re-submit the original
write request in that case. (See the previous commit for more
reasoning about why this is appropriate.)
Rename some variables in rbd_img_obj_parent_read_full_callback()
to match the convention used in the previous patch.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
---
drivers/block/rbd.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4edcb6d85f01..5c2731859e8a 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2319,7 +2319,7 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
struct rbd_device *rbd_dev;
struct page **pages;
u32 page_count;
- int result;
+ int img_result;
u64 parent_length;
u64 offset;
u64 length;
@@ -2338,7 +2338,7 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
orig_request = img_request->obj_request;
rbd_assert(orig_request != NULL);
rbd_assert(obj_request_type_valid(orig_request->type));
- result = img_request->result;
+ img_result = img_request->result;
parent_length = img_request->length;
rbd_assert(parent_length == img_request->xferred);
rbd_img_request_put(img_request);
@@ -2347,7 +2347,22 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
rbd_dev = orig_request->img_request->rbd_dev;
rbd_assert(rbd_dev);
- if (result)
+ /*
+ * If the overlap has become 0 (most likely because the
+ * image has been flattened) we need to free the pages
+ * and re-submit the original write request.
+ */
+ if (!rbd_dev->parent_overlap) {
+ struct ceph_osd_client *osdc;
+
+ ceph_release_page_vector(pages, page_count);
+ osdc = &rbd_dev->rbd_client->client->osdc;
+ img_result = rbd_obj_request_submit(osdc, orig_request);
+ if (!img_result)
+ return;
+ }
+
+ if (img_result)
goto out_err;
/*
@@ -2356,7 +2371,7 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
* request. Allocate the new copyup osd request for the
* original request, and release the old one.
*/
- result = -ENOMEM;
+ img_result = -ENOMEM;
osd_req = rbd_osd_req_create_copyup(orig_request);
if (!osd_req)
goto out_err;
@@ -2391,13 +2406,13 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
orig_request->callback = rbd_img_obj_copyup_callback;
osdc = &rbd_dev->rbd_client->client->osdc;
- result = rbd_obj_request_submit(osdc, orig_request);
- if (!result)
+ img_result = rbd_obj_request_submit(osdc, orig_request);
+ if (!img_result)
return;
out_err:
/* Record the error code and complete the request */
- orig_request->result = result;
+ orig_request->result = img_result;
orig_request->xferred = 0;
obj_request_done_set(orig_request);
rbd_obj_request_complete(orig_request);
--
2.20.1