Patch "drbd: remove usage of list iterator variable after loop" has been added to the 5.17-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drbd: remove usage of list iterator variable after loop

to the 5.17-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drbd-remove-usage-of-list-iterator-variable-after-lo.patch
and it can be found in the queue-5.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a5d82ac5d76e5e9cbb8edd7203e0571569a1d0de
Author: Jakob Koschel <jakobkoschel@xxxxxxxxx>
Date:   Fri Apr 1 00:03:48 2022 +0200

    drbd: remove usage of list iterator variable after loop
    
    [ Upstream commit 901aeda62efa21f2eae937bccb71b49ae531be06 ]
    
    In preparation to limit the scope of a list iterator to the list
    traversal loop, use a dedicated pointer to iterate through the list [1].
    
    Since that variable should not be used past the loop iteration, a
    separate variable is used to 'remember the current location within the
    loop'.
    
    To either continue iterating from that position or skip the iteration
    (if the previous iteration was complete) list_prepare_entry() is used.
    
    Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@xxxxxxxxxxxxxx/ [1]
    Signed-off-by: Jakob Koschel <jakobkoschel@xxxxxxxxx>
    Link: https://lore.kernel.org/r/20220331220349.885126-1-jakobkoschel@xxxxxxxxx
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 478ba959362c..416f4f48f69b 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -171,7 +171,7 @@ void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 		unsigned int set_size)
 {
 	struct drbd_request *r;
-	struct drbd_request *req = NULL;
+	struct drbd_request *req = NULL, *tmp = NULL;
 	int expect_epoch = 0;
 	int expect_size = 0;
 
@@ -225,8 +225,11 @@ void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 	 * to catch requests being barrier-acked "unexpectedly".
 	 * It usually should find the same req again, or some READ preceding it. */
 	list_for_each_entry(req, &connection->transfer_log, tl_requests)
-		if (req->epoch == expect_epoch)
+		if (req->epoch == expect_epoch) {
+			tmp = req;
 			break;
+		}
+	req = list_prepare_entry(tmp, &connection->transfer_log, tl_requests);
 	list_for_each_entry_safe_from(req, r, &connection->transfer_log, tl_requests) {
 		if (req->epoch != expect_epoch)
 			break;