diff options
| author | Jan Beulich <JBeulich@suse.com> | 2016-07-07 02:05:46 -0600 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2016-07-22 08:23:45 -0400 |
| commit | ff595325ed556fb4b83af5b9ffd5c427c18405d7 (patch) | |
| tree | 162b59688b4783ec48266ac153f4a2a9ed13eaa1 /drivers/block/xen-blkfront.c | |
| parent | 6694389af9be4d1eb8d3313788a902f0590fb8c2 (diff) | |
xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
... for single items being collected: It is more typesafe (as the
compiler can check format string and to-be-written-to variable match)
and requires one less parameter to be passed.
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkfront.c')
| -rw-r--r-- | drivers/block/xen-blkfront.c | 43 |
1 files changed, 19 insertions, 24 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2e6d1e9c3345..ca0536eb7037 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -2208,10 +2208,9 @@ static void blkfront_setup_discard(struct blkfront_info *info) info->discard_granularity = discard_granularity; info->discard_alignment = discard_alignment; } - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "discard-secure", "%d", &discard_secure, - NULL); - if (!err) + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "discard-secure", "%u", &discard_secure); + if (err > 0) info->feature_secdiscard = !!discard_secure; } @@ -2310,9 +2309,8 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) info->feature_flush = 0; - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "feature-barrier", "%d", &barrier, - NULL); + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-barrier", "%d", &barrier); /* * If there's no "feature-barrier" defined, then it means @@ -2321,38 +2319,35 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) * * If there are barriers, then we use flush. */ - if (!err && barrier) + if (err > 0 && barrier) info->feature_flush = REQ_FLUSH | REQ_FUA; /* * And if there is "feature-flush-cache" use that above * barriers. */ - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "feature-flush-cache", "%d", &flush, - NULL); + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-flush-cache", "%d", &flush); - if (!err && flush) + if (err > 0 && flush) info->feature_flush = REQ_FLUSH; - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "feature-discard", "%d", &discard, - NULL); + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-discard", "%d", &discard); - if (!err && discard) + if (err > 0 && discard) blkfront_setup_discard(info); - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "feature-persistent", "%u", &persistent, - NULL); - if (err) + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-persistent", "%d", &persistent); + if (err <= 0) info->feature_persistent = 0; else info->feature_persistent = persistent; - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, - "feature-max-indirect-segments", "%u", &indirect_segments, - NULL); - if (err) + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-max-indirect-segments", "%u", + &indirect_segments); + if (err <= 0) info->max_indirect_segments = 0; else info->max_indirect_segments = min(indirect_segments, |