[Xen-devel] [PATCH] xen-blkfront: feature flags handling adjustments

["Jan Beulich" <JBeulich@xxxxxxxx>]

Don't truncate the "feature-persistent" value read from xenstore: Any
non-zero value is supposed to enable the feature, just like is already
being done for feature_secdiscard.

Just like the other feature_* fields, feature_flush and feature_fua are
boolean flags, and hence fit well into a single bit.

Keep all bit fields together to limit gaps.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 drivers/block/xen-blkfront.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- 4.10-rc5/drivers/block/xen-blkfront.c
+++ 4.10-rc5-xen-blkfront-feature-flags/drivers/block/xen-blkfront.c
@@ -197,13 +197,13 @@ struct blkfront_info
        /* Number of pages per ring buffer. */
        unsigned int nr_ring_pages;
        struct request_queue *rq;
-       unsigned int feature_flush;
-       unsigned int feature_fua;
+       unsigned int feature_flush:1;
+       unsigned int feature_fua:1;
        unsigned int feature_discard:1;
        unsigned int feature_secdiscard:1;
+       unsigned int feature_persistent:1;
        unsigned int discard_granularity;
        unsigned int discard_alignment;
-       unsigned int feature_persistent:1;
        /* Number of 4KB segments handled */
        unsigned int max_indirect_segments;
        int is_ready;
@@ -2323,8 +2323,8 @@ static void blkfront_gather_backend_feat
                blkfront_setup_discard(info);
 
        info->feature_persistent =
-               xenbus_read_unsigned(info->xbdev->otherend,
-                                    "feature-persistent", 0);
+               !!xenbus_read_unsigned(info->xbdev->otherend,
+                                      "feature-persistent", 0);
 
        indirect_segments = xenbus_read_unsigned(info->xbdev->otherend,
                                        "feature-max-indirect-segments", 0);




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