From 4dae76705fc8f9854bb732f9944e7ff9ba7a8e9f Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Tue, 13 Mar 2012 18:43:23 -0400 Subject: xen/blkback: Squash the discard support for 'file' and 'phy' type. The only reason for the distinction was for the special case of 'file' (which is assumed to be loopback device), was to reach inside the loopback device, find the underlaying file, and call fallocate on it. Fortunately "xen-blkback: convert hole punching to discard request on loop devices" removes that use-case and we now based the discard support based on blk_queue_discard(q) and extract all appropriate parameters from the 'struct request_queue'. CC: Li Dongyang Acked-by: Jan Beulich [v1: Dropping pointless initializer and keeping blank line] [v2: Remove the kfree as it is not used anymore] Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkback/blkback.c | 19 +++++----- drivers/block/xen-blkback/common.h | 6 ---- drivers/block/xen-blkback/xenbus.c | 70 ++++++++++++++----------------------- 3 files changed, 34 insertions(+), 61 deletions(-) (limited to 'drivers/block/xen-blkback') diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 70caa896997..73f196ca713 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -398,21 +398,18 @@ static int dispatch_discard_io(struct xen_blkif *blkif, int err = 0; int status = BLKIF_RSP_OKAY; struct block_device *bdev = blkif->vbd.bdev; + unsigned long secure; blkif->st_ds_req++; xen_blkif_get(blkif); - if (blkif->blk_backend_type == BLKIF_BACKEND_PHY || - blkif->blk_backend_type == BLKIF_BACKEND_FILE) { - unsigned long secure = (blkif->vbd.discard_secure && - (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ? - BLKDEV_DISCARD_SECURE : 0; - err = blkdev_issue_discard(bdev, - req->u.discard.sector_number, - req->u.discard.nr_sectors, - GFP_KERNEL, secure); - } else - err = -EOPNOTSUPP; + secure = (blkif->vbd.discard_secure && + (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ? + BLKDEV_DISCARD_SECURE : 0; + + err = blkdev_issue_discard(bdev, req->u.discard.sector_number, + req->u.discard.nr_sectors, + GFP_KERNEL, secure); if (err == -EOPNOTSUPP) { pr_debug(DRV_PFX "discard op failed, not supported\n"); diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index d0ee7edc9be..773cf27dc23 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -146,11 +146,6 @@ enum blkif_protocol { BLKIF_PROTOCOL_X86_64 = 3, }; -enum blkif_backend_type { - BLKIF_BACKEND_PHY = 1, - BLKIF_BACKEND_FILE = 2, -}; - struct xen_vbd { /* What the domain refers to this vbd as. */ blkif_vdev_t handle; @@ -177,7 +172,6 @@ struct xen_blkif { unsigned int irq; /* Comms information. */ enum blkif_protocol blk_protocol; - enum blkif_backend_type blk_backend_type; union blkif_back_rings blk_rings; void *blk_ring; /* The VBD attached to this interface. */ diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 24a2fb57e5d..d417c13e027 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -390,61 +390,43 @@ int xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) { struct xenbus_device *dev = be->dev; struct xen_blkif *blkif = be->blkif; - char *type; int err; int state = 0; + struct block_device *bdev = be->blkif->vbd.bdev; + struct request_queue *q = bdev_get_queue(bdev); - type = xenbus_read(XBT_NIL, dev->nodename, "type", NULL); - if (!IS_ERR(type)) { - if (strncmp(type, "file", 4) == 0) { - state = 1; - blkif->blk_backend_type = BLKIF_BACKEND_FILE; + if (blk_queue_discard(q)) { + err = xenbus_printf(xbt, dev->nodename, + "discard-granularity", "%u", + q->limits.discard_granularity); + if (err) { + xenbus_dev_fatal(dev, err, + "writing discard-granularity"); + goto out; + } + err = xenbus_printf(xbt, dev->nodename, + "discard-alignment", "%u", + q->limits.discard_alignment); + if (err) { + xenbus_dev_fatal(dev, err, + "writing discard-alignment"); + goto out; } - if (strncmp(type, "phy", 3) == 0) { - struct block_device *bdev = be->blkif->vbd.bdev; - struct request_queue *q = bdev_get_queue(bdev); - if (blk_queue_discard(q)) { - err = xenbus_printf(xbt, dev->nodename, - "discard-granularity", "%u", - q->limits.discard_granularity); - if (err) { - xenbus_dev_fatal(dev, err, - "writing discard-granularity"); - goto kfree; - } - err = xenbus_printf(xbt, dev->nodename, - "discard-alignment", "%u", - q->limits.discard_alignment); - if (err) { - xenbus_dev_fatal(dev, err, - "writing discard-alignment"); - goto kfree; - } - state = 1; - blkif->blk_backend_type = BLKIF_BACKEND_PHY; - } - /* Optional. */ - err = xenbus_printf(xbt, dev->nodename, - "discard-secure", "%d", - blkif->vbd.discard_secure); - if (err) { - xenbus_dev_fatal(dev, err, + state = 1; + /* Optional. */ + err = xenbus_printf(xbt, dev->nodename, + "discard-secure", "%d", + blkif->vbd.discard_secure); + if (err) { + xenbus_dev_fatal(dev, err, "writting discard-secure"); - goto kfree; - } + goto out; } - } else { - err = PTR_ERR(type); - xenbus_dev_fatal(dev, err, "reading type"); - goto out; } - err = xenbus_printf(xbt, dev->nodename, "feature-discard", "%d", state); if (err) xenbus_dev_fatal(dev, err, "writing feature-discard"); -kfree: - kfree(type); out: return err; } -- cgit v1.2.3-18-g5258