Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 475 insertions, 0 deletions

diff --git a/drivers/md/dm-ebs-target.c b/drivers/md/dm-ebs-target.c
new file mode 100644
index 000000000..512cc6cea
--- /dev/null
+++ b/drivers/md/dm-ebs-target.c
@@ -0,0 +1,475 @@
+/*
+ * Copyright (C) 2020 Red Hat GmbH
+ *
+ * This file is released under the GPL.
+ *
+ * Device-mapper target to emulate smaller logical block
+ * size on backing devices exposing (natively) larger ones.
+ *
+ * E.g. 512 byte sector emulation on 4K native disks.
+ */
+
+#include "dm.h"
+#include <linux/module.h>
+#include <linux/workqueue.h>
+#include <linux/dm-bufio.h>
+
+#define DM_MSG_PREFIX "ebs"
+
+static void ebs_dtr(struct dm_target *ti);
+
+/* Emulated block size context. */
+struct ebs_c {
+	struct dm_dev *dev;		/* Underlying device to emulate block size on. */
+	struct dm_bufio_client *bufio;	/* Use dm-bufio for read and read-modify-write processing. */
+	struct workqueue_struct *wq;	/* Workqueue for ^ processing of bios. */
+	struct work_struct ws;		/* Work item used for ^. */
+	struct bio_list bios_in;	/* Worker bios input list. */
+	spinlock_t lock;		/* Guard bios input list above. */
+	sector_t start;			/* <start> table line argument, see ebs_ctr below. */
+	unsigned int e_bs;		/* Emulated block size in sectors exposed to upper layer. */
+	unsigned int u_bs;		/* Underlying block size in sectors retrieved from/set on lower layer device. */
+	unsigned char block_shift;	/* bitshift sectors -> blocks used in dm-bufio API. */
+	bool u_bs_set:1;		/* Flag to indicate underlying block size is set on table line. */
+};
+
+static inline sector_t __sector_to_block(struct ebs_c *ec, sector_t sector)
+{
+	return sector >> ec->block_shift;
+}
+
+static inline sector_t __block_mod(sector_t sector, unsigned int bs)
+{
+	return sector & (bs - 1);
+}
+
+/* Return number of blocks for a bio, accounting for misalignment of start and end sectors. */
+static inline unsigned int __nr_blocks(struct ebs_c *ec, struct bio *bio)
+{
+	sector_t end_sector = __block_mod(bio->bi_iter.bi_sector, ec->u_bs) + bio_sectors(bio);
+
+	return __sector_to_block(ec, end_sector) + (__block_mod(end_sector, ec->u_bs) ? 1 : 0);
+}
+
+static inline bool __ebs_check_bs(unsigned int bs)
+{
+	return bs && is_power_of_2(bs);
+}
+
+/*
+ * READ/WRITE:
+ *
+ * copy blocks between bufio blocks and bio vector's (partial/overlapping) pages.
+ */
+static int __ebs_rw_bvec(struct ebs_c *ec, enum req_op op, struct bio_vec *bv,
+			 struct bvec_iter *iter)
+{
+	int r = 0;
+	unsigned char *ba, *pa;
+	unsigned int cur_len;
+	unsigned int bv_len = bv->bv_len;
+	unsigned int buf_off = to_bytes(__block_mod(iter->bi_sector, ec->u_bs));
+	sector_t block = __sector_to_block(ec, iter->bi_sector);
+	struct dm_buffer *b;
+
+	if (unlikely(!bv->bv_page || !bv_len))
+		return -EIO;
+
+	pa = bvec_virt(bv);
+
+	/* Handle overlapping page <-> blocks */
+	while (bv_len) {
+		cur_len = min(dm_bufio_get_block_size(ec->bufio) - buf_off, bv_len);
+
+		/* Avoid reading for writes in case bio vector's page overwrites block completely. */
+		if (op == REQ_OP_READ || buf_off || bv_len < dm_bufio_get_block_size(ec->bufio))
+			ba = dm_bufio_read(ec->bufio, block, &b);
+		else
+			ba = dm_bufio_new(ec->bufio, block, &b);
+
+		if (IS_ERR(ba)) {
+			/*
+			 * Carry on with next buffer, if any, to issue all possible
+			 * data but return error.
+			 */
+			r = PTR_ERR(ba);
+		} else {
+			/* Copy data to/from bio to buffer if read/new was successful above. */
+			ba += buf_off;
+			if (op == REQ_OP_READ) {
+				memcpy(pa, ba, cur_len);
+				flush_dcache_page(bv->bv_page);
+			} else {
+				flush_dcache_page(bv->bv_page);
+				memcpy(ba, pa, cur_len);
+				dm_bufio_mark_partial_buffer_dirty(b, buf_off, buf_off + cur_len);
+			}
+
+			dm_bufio_release(b);
+		}
+
+		pa += cur_len;
+		bv_len -= cur_len;
+		buf_off = 0;
+		block++;
+	}
+
+	return r;
+}
+
+/* READ/WRITE: iterate bio vector's copying between (partial) pages and bufio blocks. */
+static int __ebs_rw_bio(struct ebs_c *ec, enum req_op op, struct bio *bio)
+{
+	int r = 0, rr;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+
+	bio_for_each_bvec(bv, bio, iter) {
+		rr = __ebs_rw_bvec(ec, op, &bv, &iter);
+		if (rr)
+			r = rr;
+	}
+
+	return r;
+}
+
+/*
+ * Discard bio's blocks, i.e. pass discards down.
+ *
+ * Avoid discarding partial blocks at beginning and end;
+ * return 0 in case no blocks can be discarded as a result.
+ */
+static int __ebs_discard_bio(struct ebs_c *ec, struct bio *bio)
+{
+	sector_t block, blocks, sector = bio->bi_iter.bi_sector;
+
+	block = __sector_to_block(ec, sector);
+	blocks = __nr_blocks(ec, bio);
+
+	/*
+	 * Partial first underlying block (__nr_blocks() may have
+	 * resulted in one block).
+	 */
+	if (__block_mod(sector, ec->u_bs)) {
+		block++;
+		blocks--;
+	}
+
+	/* Partial last underlying block if any. */
+	if (blocks && __block_mod(bio_end_sector(bio), ec->u_bs))
+		blocks--;
+
+	return blocks ? dm_bufio_issue_discard(ec->bufio, block, blocks) : 0;
+}
+
+/* Release blocks them from the bufio cache. */
+static void __ebs_forget_bio(struct ebs_c *ec, struct bio *bio)
+{
+	sector_t blocks, sector = bio->bi_iter.bi_sector;
+
+	blocks = __nr_blocks(ec, bio);
+
+	dm_bufio_forget_buffers(ec->bufio, __sector_to_block(ec, sector), blocks);
+}
+
+/* Worker function to process incoming bios. */
+static void __ebs_process_bios(struct work_struct *ws)
+{
+	int r;
+	bool write = false;
+	sector_t block1, block2;
+	struct ebs_c *ec = container_of(ws, struct ebs_c, ws);
+	struct bio *bio;
+	struct bio_list bios;
+
+	bio_list_init(&bios);
+
+	spin_lock_irq(&ec->lock);
+	bios = ec->bios_in;
+	bio_list_init(&ec->bios_in);
+	spin_unlock_irq(&ec->lock);
+
+	/* Prefetch all read and any mis-aligned write buffers */
+	bio_list_for_each(bio, &bios) {
+		block1 = __sector_to_block(ec, bio->bi_iter.bi_sector);
+		if (bio_op(bio) == REQ_OP_READ)
+			dm_bufio_prefetch(ec->bufio, block1, __nr_blocks(ec, bio));
+		else if (bio_op(bio) == REQ_OP_WRITE && !(bio->bi_opf & REQ_PREFLUSH)) {
+			block2 = __sector_to_block(ec, bio_end_sector(bio));
+			if (__block_mod(bio->bi_iter.bi_sector, ec->u_bs))
+				dm_bufio_prefetch(ec->bufio, block1, 1);
+			if (__block_mod(bio_end_sector(bio), ec->u_bs) && block2 != block1)
+				dm_bufio_prefetch(ec->bufio, block2, 1);
+		}
+	}
+
+	bio_list_for_each(bio, &bios) {
+		r = -EIO;
+		if (bio_op(bio) == REQ_OP_READ)
+			r = __ebs_rw_bio(ec, REQ_OP_READ, bio);
+		else if (bio_op(bio) == REQ_OP_WRITE) {
+			write = true;
+			r = __ebs_rw_bio(ec, REQ_OP_WRITE, bio);
+		} else if (bio_op(bio) == REQ_OP_DISCARD) {
+			__ebs_forget_bio(ec, bio);
+			r = __ebs_discard_bio(ec, bio);
+		}
+
+		if (r < 0)
+			bio->bi_status = errno_to_blk_status(r);
+	}
+
+	/*
+	 * We write dirty buffers after processing I/O on them
+	 * but before we endio thus addressing REQ_FUA/REQ_SYNC.
+	 */
+	r = write ? dm_bufio_write_dirty_buffers(ec->bufio) : 0;
+
+	while ((bio = bio_list_pop(&bios))) {
+		/* Any other request is endioed. */
+		if (unlikely(r && bio_op(bio) == REQ_OP_WRITE))
+			bio_io_error(bio);
+		else
+			bio_endio(bio);
+	}
+}
+
+/*
+ * Construct an emulated block size mapping: <dev_path> <offset> <ebs> [<ubs>]
+ *
+ * <dev_path>: path of the underlying device
+ * <offset>: offset in 512 bytes sectors into <dev_path>
+ * <ebs>: emulated block size in units of 512 bytes exposed to the upper layer
+ * [<ubs>]: underlying block size in units of 512 bytes imposed on the lower layer;
+ * 	    optional, if not supplied, retrieve logical block size from underlying device
+ */
+static int ebs_ctr(struct dm_target *ti, unsigned int argc, char **argv)
+{
+	int r;
+	unsigned short tmp1;
+	unsigned long long tmp;
+	char dummy;
+	struct ebs_c *ec;
+
+	if (argc < 3 || argc > 4) {
+		ti->error = "Invalid argument count";
+		return -EINVAL;
+	}
+
+	ec = ti->private = kzalloc(sizeof(*ec), GFP_KERNEL);
+	if (!ec) {
+		ti->error = "Cannot allocate ebs context";
+		return -ENOMEM;
+	}
+
+	r = -EINVAL;
+	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 ||
+	    tmp != (sector_t)tmp ||
+	    (sector_t)tmp >= ti->len) {
+		ti->error = "Invalid device offset sector";
+		goto bad;
+	}
+	ec->start = tmp;
+
+	if (sscanf(argv[2], "%hu%c", &tmp1, &dummy) != 1 ||
+	    !__ebs_check_bs(tmp1) ||
+	    to_bytes(tmp1) > PAGE_SIZE) {
+		ti->error = "Invalid emulated block size";
+		goto bad;
+	}
+	ec->e_bs = tmp1;
+
+	if (argc > 3) {
+		if (sscanf(argv[3], "%hu%c", &tmp1, &dummy) != 1 || !__ebs_check_bs(tmp1)) {
+			ti->error = "Invalid underlying block size";
+			goto bad;
+		}
+		ec->u_bs = tmp1;
+		ec->u_bs_set = true;
+	} else
+		ec->u_bs_set = false;
+
+	r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &ec->dev);
+	if (r) {
+		ti->error = "Device lookup failed";
+		ec->dev = NULL;
+		goto bad;
+	}
+
+	r = -EINVAL;
+	if (!ec->u_bs_set) {
+		ec->u_bs = to_sector(bdev_logical_block_size(ec->dev->bdev));
+		if (!__ebs_check_bs(ec->u_bs)) {
+			ti->error = "Invalid retrieved underlying block size";
+			goto bad;
+		}
+	}
+
+	if (!ec->u_bs_set && ec->e_bs == ec->u_bs)
+		DMINFO("Emulation superfluous: emulated equal to underlying block size");
+
+	if (__block_mod(ec->start, ec->u_bs)) {
+		ti->error = "Device offset must be multiple of underlying block size";
+		goto bad;
+	}
+
+	ec->bufio = dm_bufio_client_create(ec->dev->bdev, to_bytes(ec->u_bs), 1,
+					   0, NULL, NULL, 0);
+	if (IS_ERR(ec->bufio)) {
+		ti->error = "Cannot create dm bufio client";
+		r = PTR_ERR(ec->bufio);
+		ec->bufio = NULL;
+		goto bad;
+	}
+
+	ec->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
+	if (!ec->wq) {
+		ti->error = "Cannot create dm-" DM_MSG_PREFIX " workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	ec->block_shift = __ffs(ec->u_bs);
+	INIT_WORK(&ec->ws, &__ebs_process_bios);
+	bio_list_init(&ec->bios_in);
+	spin_lock_init(&ec->lock);
+
+	ti->num_flush_bios = 1;
+	ti->num_discard_bios = 1;
+	ti->num_secure_erase_bios = 0;
+	ti->num_write_zeroes_bios = 0;
+	return 0;
+bad:
+	ebs_dtr(ti);
+	return r;
+}
+
+static void ebs_dtr(struct dm_target *ti)
+{
+	struct ebs_c *ec = ti->private;
+
+	if (ec->wq)
+		destroy_workqueue(ec->wq);
+	if (ec->bufio)
+		dm_bufio_client_destroy(ec->bufio);
+	if (ec->dev)
+		dm_put_device(ti, ec->dev);
+	kfree(ec);
+}
+
+static int ebs_map(struct dm_target *ti, struct bio *bio)
+{
+	struct ebs_c *ec = ti->private;
+
+	bio_set_dev(bio, ec->dev->bdev);
+	bio->bi_iter.bi_sector = ec->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
+
+	if (unlikely(bio_op(bio) == REQ_OP_FLUSH))
+		return DM_MAPIO_REMAPPED;
+	/*
+	 * Only queue for bufio processing in case of partial or overlapping buffers
+	 * -or-
+	 * emulation with ebs == ubs aiming for tests of dm-bufio overhead.
+	 */
+	if (likely(__block_mod(bio->bi_iter.bi_sector, ec->u_bs) ||
+		   __block_mod(bio_end_sector(bio), ec->u_bs) ||
+		   ec->e_bs == ec->u_bs)) {
+		spin_lock_irq(&ec->lock);
+		bio_list_add(&ec->bios_in, bio);
+		spin_unlock_irq(&ec->lock);
+
+		queue_work(ec->wq, &ec->ws);
+
+		return DM_MAPIO_SUBMITTED;
+	}
+
+	/* Forget any buffer content relative to this direct backing device I/O. */
+	__ebs_forget_bio(ec, bio);
+
+	return DM_MAPIO_REMAPPED;
+}
+
+static void ebs_status(struct dm_target *ti, status_type_t type,
+		       unsigned status_flags, char *result, unsigned maxlen)
+{
+	struct ebs_c *ec = ti->private;
+
+	switch (type) {
+	case STATUSTYPE_INFO:
+		*result = '\0';
+		break;
+	case STATUSTYPE_TABLE:
+		snprintf(result, maxlen, ec->u_bs_set ? "%s %llu %u %u" : "%s %llu %u",
+			 ec->dev->name, (unsigned long long) ec->start, ec->e_bs, ec->u_bs);
+		break;
+	case STATUSTYPE_IMA:
+		*result = '\0';
+		break;
+	}
+}
+
+static int ebs_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
+{
+	struct ebs_c *ec = ti->private;
+	struct dm_dev *dev = ec->dev;
+
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	*bdev = dev->bdev;
+	return !!(ec->start || ti->len != bdev_nr_sectors(dev->bdev));
+}
+
+static void ebs_io_hints(struct dm_target *ti, struct queue_limits *limits)
+{
+	struct ebs_c *ec = ti->private;
+
+	limits->logical_block_size = to_bytes(ec->e_bs);
+	limits->physical_block_size = to_bytes(ec->u_bs);
+	limits->alignment_offset = limits->physical_block_size;
+	blk_limits_io_min(limits, limits->logical_block_size);
+}
+
+static int ebs_iterate_devices(struct dm_target *ti,
+				  iterate_devices_callout_fn fn, void *data)
+{
+	struct ebs_c *ec = ti->private;
+
+	return fn(ti, ec->dev, ec->start, ti->len, data);
+}
+
+static struct target_type ebs_target = {
+	.name		 = "ebs",
+	.version	 = {1, 0, 1},
+	.features	 = DM_TARGET_PASSES_INTEGRITY,
+	.module		 = THIS_MODULE,
+	.ctr		 = ebs_ctr,
+	.dtr		 = ebs_dtr,
+	.map		 = ebs_map,
+	.status		 = ebs_status,
+	.io_hints	 = ebs_io_hints,
+	.prepare_ioctl	 = ebs_prepare_ioctl,
+	.iterate_devices = ebs_iterate_devices,
+};
+
+static int __init dm_ebs_init(void)
+{
+	int r = dm_register_target(&ebs_target);
+
+	if (r < 0)
+		DMERR("register failed %d", r);
+
+	return r;
+}
+
+static void dm_ebs_exit(void)
+{
+	dm_unregister_target(&ebs_target);
+}
+
+module_init(dm_ebs_init);
+module_exit(dm_ebs_exit);
+
+MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
+MODULE_DESCRIPTION(DM_NAME " emulated block size target");
+MODULE_LICENSE("GPL");