This is a note to let you know that I've just added the patch titled
xen-blkfront: Advertise feature-persistent as user requested
to the 5.19-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:
xen-blkfront-advertise-feature-persistent-as-user-requested.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9f5e0fe5d05f7e8de7f39b2b10089834eb0ff787 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@xxxxxxxxxx>
Date: Wed, 31 Aug 2022 16:58:23 +0000
Subject: xen-blkfront: Advertise feature-persistent as user requested
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From: SeongJae Park <sj@xxxxxxxxxx>
commit 9f5e0fe5d05f7e8de7f39b2b10089834eb0ff787 upstream.
The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature. However, commit
74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent
grants") made a field of blkfront, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value. As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.
This commit fixes the misuse of the semantic by making blkfront saves
the parameter value in a separate place and advertises the support based
on only the saved value.
Fixes: 74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent grants")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x
Suggested-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Tested-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Link: https://lore.kernel.org/r/20220831165824.94815-3-sj@xxxxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/xen-blkfront.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -213,6 +213,9 @@ struct blkfront_info
unsigned int feature_fua:1;
unsigned int feature_discard:1;
unsigned int feature_secdiscard:1;
+ /* Connect-time cached feature_persistent parameter */
+ unsigned int feature_persistent_parm:1;
+ /* Persistent grants feature negotiation result */
unsigned int feature_persistent:1;
unsigned int bounce:1;
unsigned int discard_granularity;
@@ -1848,7 +1851,7 @@ again:
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u",
- info->feature_persistent);
+ info->feature_persistent_parm);
if (err)
dev_warn(&dev->dev,
"writing persistent grants feature to xenbus");
@@ -2281,7 +2284,8 @@ static void blkfront_gather_backend_feat
if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0))
blkfront_setup_discard(info);
- if (feature_persistent)
+ info->feature_persistent_parm = feature_persistent;
+ if (info->feature_persistent_parm)
info->feature_persistent =
!!xenbus_read_unsigned(info->xbdev->otherend,
"feature-persistent", 0);
Patches currently in stable-queue which might be from sj@xxxxxxxxxx are
queue-5.19/xen-blkfront-cache-feature_persistent-value-before-advertisement.patch
queue-5.19/xen-blkfront-advertise-feature-persistent-as-user-requested.patch
queue-5.19/xen-blkback-advertise-feature-persistent-as-user-requested.patch
