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xen/blkfront: remove redundant flush_op

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flush_op is unambiguously defined by feature_flush:
    REQ_FUA | REQ_FLUSH -> BLKIF_OP_WRITE_BARRIER
    REQ_FLUSH -> BLKIF_OP_FLUSH_DISKCACHE
    0 -> 0
and thus can be removed. This is just a cleanup.

The patch was suggested by Boris Ostrovsky.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Vitaly Kuznetsov 2014-12-09 15:25:10 +01:00 committed by Konrad Rzeszutek Wilk
parent ad42d391ae
commit fdf9b96503
1 changed files with 31 additions and 20 deletions
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51
drivers/block/xen-blkfront.c
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@ -126,7 +126,6 @@ struct blkfront_info
unsigned int persistent_gnts_c;
unsigned long shadow_free;
unsigned int feature_flush;
unsigned int flush_op;
unsigned int feature_discard:1;
unsigned int feature_secdiscard:1;
unsigned int discard_granularity;
@ -479,7 +478,19 @@ static int blkif_queue_request(struct request *req)
* way. (It's also a FLUSH+FUA, since it is
* guaranteed ordered WRT previous writes.)
*/
ring_req->operation = info->flush_op;
switch (info->feature_flush &
((REQ_FLUSH|REQ_FUA))) {
case REQ_FLUSH|REQ_FUA:
ring_req->operation =
BLKIF_OP_WRITE_BARRIER;
break;
case REQ_FLUSH:
ring_req->operation =
BLKIF_OP_FLUSH_DISKCACHE;
break;
default:
ring_req->operation = 0;
}
}
ring_req->u.rw.nr_segments = nseg;
}
@ -685,20 +696,26 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
return 0;
}
static const char *flush_info(unsigned int feature_flush)
{
switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) {
case REQ_FLUSH|REQ_FUA:
return "barrier: enabled;";
case REQ_FLUSH:
return "flush diskcache: enabled;";
default:
return "barrier or flush: disabled;";
}
}
static void xlvbd_flush(struct blkfront_info *info)
{
blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: %s: %s %s %s %s %s\n",
info->gd->disk_name,
info->flush_op == BLKIF_OP_WRITE_BARRIER ?
"barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ?
"flush diskcache" : "barrier or flush"),
info->feature_flush ? "enabled;" : "disabled;",
"persistent grants:",
info->feature_persistent ? "enabled;" : "disabled;",
"indirect descriptors:",
info->max_indirect_segments ? "enabled;" : "disabled;");
pr_info("blkfront: %s: %s %s %s %s %s\n",
info->gd->disk_name, flush_info(info->feature_flush),
"persistent grants:", info->feature_persistent ?
"enabled;" : "disabled;", "indirect descriptors:",
info->max_indirect_segments ? "enabled;" : "disabled;");
}
static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset)
@ -1190,7 +1207,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
if (error == -EOPNOTSUPP)
error = 0;
info->feature_flush = 0;
info->flush_op = 0;
xlvbd_flush(info);
}
/* fall through */
@ -1810,7 +1826,6 @@ static void blkfront_connect(struct blkfront_info *info)
physical_sector_size = sector_size;
info->feature_flush = 0;
info->flush_op = 0;
err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
"feature-barrier", "%d", &barrier,
@ -1823,10 +1838,8 @@ static void blkfront_connect(struct blkfront_info *info)
*
* If there are barriers, then we use flush.
*/
if (!err && barrier) {
if (!err && barrier)
info->feature_flush = REQ_FLUSH | REQ_FUA;
info->flush_op = BLKIF_OP_WRITE_BARRIER;
}
/*
* And if there is "feature-flush-cache" use that above
* barriers.
@ -1835,10 +1848,8 @@ static void blkfront_connect(struct blkfront_info *info)
"feature-flush-cache", "%d", &flush,
NULL);
if (!err && flush) {
if (!err && flush)
info->feature_flush = REQ_FLUSH;
info->flush_op = BLKIF_OP_FLUSH_DISKCACHE;
}
err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
"feature-discard", "%d", &discard,