xen/blk[front|back]: Enhance discard support with secure erasing support. (5ea42986) · Commits · 戴 / test

drivers/block/xen-blkback/blkback.c

+12 −6

Original line number	Diff line number	Diff line
		@@ -422,13 +422,16 @@ static void xen_blk_discard(struct xen_blkif blkif, struct blkif_request req)
		int status = BLKIF_RSP_OKAY;
		struct block_device *bdev = blkif->vbd.bdev;

		if (blkif->blk_backend_type == BLKIF_BACKEND_PHY)
		if (blkif->blk_backend_type == BLKIF_BACKEND_PHY) {
		unsigned long secure = (blkif->vbd.discard_secure &&
		(req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
		BLKDEV_DISCARD_SECURE : 0;
		/* just forward the discard request */
		err = blkdev_issue_discard(bdev,
		req->u.discard.sector_number,
		req->u.discard.nr_sectors,
		GFP_KERNEL, 0);
		else if (blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
		GFP_KERNEL, secure);
		} else if (blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
		/* punch a hole in the backing file */
		struct loop_device *lo = bdev->bd_disk->private_data;
		struct file *file = lo->lo_backing_file;
		@@ -643,6 +646,9 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
		break;
		}

		if (unlikely(operation == REQ_DISCARD))
		nseg = 0;
		else
		/* Check that the number of segments is sane. */
		nseg = req->u.rw.nr_segments;

		@@ -708,7 +714,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
		* the hypercall to unmap the grants - that is all done in
		* xen_blkbk_unmap.
		*/
		if (operation != REQ_DISCARD && xen_blkbk_map(req, pending_req, seg))
		if (nseg && xen_blkbk_map(req, pending_req, seg))
		goto fail_flush;

		/*

drivers/block/xen-blkback/common.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -69,7 +69,7 @@ struct blkif_x86_32_request_rw {
		} __attribute__((__packed__));

		struct blkif_x86_32_request_discard {
		uint8_t nr_segments; /* number of segments */
		uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
		blkif_vdev_t _pad1; /* was "handle" for read/write requests */
		uint64_t id; /* private guest value, echoed in resp */
		blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
		@@ -104,7 +104,7 @@ struct blkif_x86_64_request_rw {
		} __attribute__((__packed__));

		struct blkif_x86_64_request_discard {
		uint8_t nr_segments; /* number of segments */
		uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
		blkif_vdev_t _pad1; /* was "handle" for read/write requests */
		uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
		uint64_t id;
		@@ -164,6 +164,7 @@ struct xen_vbd {
		/* Cached size parameter. */
		sector_t size;
		bool flush_support;
		bool discard_secure;
		};

		struct backend_info;
		@@ -261,6 +262,7 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst,
		dst->u.rw.seg[i] = src->u.rw.seg[i];
		break;
		case BLKIF_OP_DISCARD:
		dst->u.discard.flag = src->u.discard.flag;
		dst->u.discard.sector_number = src->u.discard.sector_number;
		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
		break;
		@@ -290,6 +292,7 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst,
		dst->u.rw.seg[i] = src->u.rw.seg[i];
		break;
		case BLKIF_OP_DISCARD:
		dst->u.discard.flag = src->u.discard.flag;
		dst->u.discard.sector_number = src->u.discard.sector_number;
		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
		break;

drivers/block/xen-blkback/xenbus.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -338,6 +338,9 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
		if (q && q->flush_flags)
		vbd->flush_support = true;

		if (q && blk_queue_secdiscard(q))
		vbd->discard_secure = true;

		DPRINTK("Successful creation of handle=%04x (dom=%u)\n",
		handle, blkif->domid);
		return 0;
		@@ -420,6 +423,15 @@ int xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be)
		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,
		"writting discard-secure");
		goto kfree;
		}
		}
		} else {
		err = PTR_ERR(type);

drivers/block/xen-blkfront.c

+31 −10

Original line number	Diff line number	Diff line
		@@ -98,7 +98,8 @@ struct blkfront_info
		unsigned long shadow_free;
		unsigned int feature_flush;
		unsigned int flush_op;
		unsigned int feature_discard;
		unsigned int feature_discard:1;
		unsigned int feature_secdiscard:1;
		unsigned int discard_granularity;
		unsigned int discard_alignment;
		int is_ready;
		@@ -305,11 +306,14 @@ static int blkif_queue_request(struct request *req)
		ring_req->operation = info->flush_op;
		}

		if (unlikely(req->cmd_flags & REQ_DISCARD)) {
		if (unlikely(req->cmd_flags & (REQ_DISCARD \| REQ_SECURE))) {
		/* id, sector_number and handle are set above. */
		ring_req->operation = BLKIF_OP_DISCARD;
		ring_req->u.discard.nr_segments = 0;
		ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
		if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard)
		ring_req->u.discard.flag = BLKIF_DISCARD_SECURE;
		else
		ring_req->u.discard.flag = 0;
		} else {
		ring_req->u.rw.nr_segments = blk_rq_map_sg(req->q, req,
		info->sg);
		@@ -426,6 +430,8 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
		blk_queue_max_discard_sectors(rq, get_capacity(gd));
		rq->limits.discard_granularity = info->discard_granularity;
		rq->limits.discard_alignment = info->discard_alignment;
		if (info->feature_secdiscard)
		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq);
		}

		/* Hard sector size and max sectors impersonate the equiv. hardware. */
		@@ -707,6 +713,8 @@ static void blkif_free(struct blkfront_info *info, int suspend)
		static void blkif_completion(struct blk_shadow *s)
		{
		int i;
		/* Do not let BLKIF_OP_DISCARD as nr_segment is in the same place
		* flag. */
		for (i = 0; i < s->req.u.rw.nr_segments; i++)
		gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL);
		}
		@@ -738,6 +746,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
		id = bret->id;
		req = info->shadow[id].request;

		if (bret->operation != BLKIF_OP_DISCARD)
		blkif_completion(&info->shadow[id]);

		add_id_to_freelist(info, id);
		@@ -751,7 +760,9 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
		info->gd->disk_name);
		error = -EOPNOTSUPP;
		info->feature_discard = 0;
		info->feature_secdiscard = 0;
		queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
		queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq);
		}
		__blk_end_request_all(req, error);
		break;
		@@ -1039,6 +1050,7 @@ static int blkif_recover(struct blkfront_info *info)
		req->u.rw.id = get_id_from_freelist(info);
		memcpy(&info->shadow[req->u.rw.id], &copy[i], sizeof(copy[i]));

		if (req->operation != BLKIF_OP_DISCARD) {
		/* Rewrite any grant references invalidated by susp/resume. */
		for (j = 0; j < req->u.rw.nr_segments; j++)
		gnttab_grant_foreign_access_ref(
		@@ -1046,6 +1058,7 @@ static int blkif_recover(struct blkfront_info *info)
		info->xbdev->otherend_id,
		pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]),
		rq_data_dir(info->shadow[req->u.rw.id].request));
		}
		info->shadow[req->u.rw.id].req = *req;

		info->ring.req_prod_pvt++;
		@@ -1137,11 +1150,13 @@ static void blkfront_setup_discard(struct blkfront_info *info)
		char *type;
		unsigned int discard_granularity;
		unsigned int discard_alignment;
		unsigned int discard_secure;

		type = xenbus_read(XBT_NIL, info->xbdev->otherend, "type", NULL);
		if (IS_ERR(type))
		return;

		info->feature_secdiscard = 0;
		if (strncmp(type, "phy", 3) == 0) {
		err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
		"discard-granularity", "%u", &discard_granularity,
		@@ -1152,6 +1167,12 @@ 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)
		info->feature_secdiscard = discard_secure;

		} else if (strncmp(type, "file", 4) == 0)
		info->feature_discard = 1;

include/xen/interface/io/blkif.h

+17 −1

Original line number	Diff line number	Diff line
		@@ -84,6 +84,21 @@ typedef uint64_t blkif_sector_t;
		* e07154r6-Data_Set_Management_Proposal_for_ATA-ACS2.doc
		* http://www.seagate.com/staticfiles/support/disc/manuals/
		* Interface%20manuals/100293068c.pdf
		* The backend can optionally provide three extra XenBus attributes to
		* further optimize the discard functionality:
		* 'discard-aligment' - Devices that support discard functionality may
		* internally allocate space in units that are bigger than the exported
		* logical block size. The discard-alignment parameter indicates how many bytes
		* the beginning of the partition is offset from the internal allocation unit's
		* natural alignment.
		* 'discard-granularity' - Devices that support discard functionality may
		* internally allocate space using units that are bigger than the logical block
		* size. The discard-granularity parameter indicates the size of the internal
		* allocation unit in bytes if reported by the device. Otherwise the
		* discard-granularity will be set to match the device's physical block size.
		* 'discard-secure' - All copies of the discarded sectors (potentially created
		* by garbage collection) must also be erased. To use this feature, the flag
		* BLKIF_DISCARD_SECURE must be set in the blkif_request_trim.
		*/
		#define BLKIF_OP_DISCARD 5

		@@ -111,7 +126,8 @@ struct blkif_request_rw {
		} __attribute__((__packed__));

		struct blkif_request_discard {
		uint8_t nr_segments; /* number of segments */
		uint8_t flag; /* BLKIF_DISCARD_SECURE or zero. */
		#define BLKIF_DISCARD_SECURE (1<<0) /* ignored if discard-secure=0 */
		blkif_vdev_t _pad1; /* only for read/write requests */
		#ifdef CONFIG_X86_64
		uint32_t _pad2; /* offsetof(blkif_req..,u.discard.id)==8*/

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