On Wed, 2011-03-09 at 22:37 +0000, Daniel Stodden wrote:
> On Wed, 2011-03-09 at 05:18 -0500, Ian Campbell wrote:
> > On Wed, 2011-03-09 at 00:42 +0000, Daniel Stodden wrote:
> > > Moves blktap2 definitions into a common header file.
> > >
> > > Includes xen/interface/io/ring.h and new ring definitions. Makes
> > > blktap build independently from xen-devel headers.
> > >
> > > New blktap_ring structs are fully congrent to blkif rings, for binary
> > > compat.
> > >
> > > Signed-off-by: Daniel Stodden <daniel.stodden@xxxxxxxxxx>
> > > ---
> > > drivers/xen/blktap/blktap.h | 66 ++++----------------------------
> > > drivers/xen/blktap/control.c | 14 +++---
> > > drivers/xen/blktap/device.c | 12 +++---
> > > drivers/xen/blktap/request.c | 8 ++--
> > > drivers/xen/blktap/ring.c | 51 ++++++++++++++-----------
> > > drivers/xen/blktap/sysfs.c | 6 +-
> > > include/linux/blktap.h | 85
> > > ++++++++++++++++++++++++++++++++++++++++++
> >
> > This new file defines the kernel<->user (tapdisk process) ring protocol,
> > right?
>
> Yes. It's exactly as far as I can go right now maintaining
> compatibility. The main objective was rather to get off xen-devel
> headers in favour of kernel sources.
>
> - includes xen/interface/io/ring.
> - doesn't include xen/interface/io/blkif.
> - certainly doesn't include xen/interface/blkif.h
> (the alignment stuff for guests).
>
> The old code used blkif and struct blkif_* definitions. The new one got
> it's own struct blktap_*s, identical as far as READ/WRITE commands go.
>
> But this also means one can develop the userland stuff independently
> from blkif.h. New commands (flush, trim, ...) get quite a bit more
> useful freedom.
>
> > I think its proper home would be under include/xen somewhere, which is
> > where the gntdev and evtchn etc driver interfaces are defined.
>
> A very long time ago, a somewhat obvious choice was made to use xen ring
> headers for the blktap user <-> kernel interface. So this header
> presently still wants xen/interface.
>
> It doesn't depend on anything xenish, nor is this a Xen driver anymore.
> I thought even with that header dependency, that's somewhat a
> linux/blktap.h already, so I made it so.
OK.
> I'm feeling some heat from boston-newxen people because in XCP I'm
> actually building blktap.hg against the kernel devel rpm contents right
> now. That's got to vanish. It's great for hacking extensions, but the
> component dependency is a bit gross, admittedly.
Sure, but you could build against a copy of the kernel source tree,
which would remove the dependency on the kernel binary RPMs.
> Once doing so, it's a standalone kernel blktap.h which can be copied
> over into userland trees, without additional definitions included.
If the other user of this interface is the tapdisk userspace, but that
includes a copy of the interface header (note: I'm not convinced that is
a good idea) then I think the right place for this copy of the header is
drivers/block/blktap/.
If on the other hand userland is building against this exact header then
include/linux is probably right given that the driver has no Xen
dependency.
> This isn't sick: Blktap2 doesn't need the full ring.h macro contents
> with memory barriers etc anyway, because the userland dispatching is
> synchronous. It could be just bare structs, and the standard PUSH/PULL
> macros are rather decoration and could be dropped (or reimplemented as
> memcpy()s).
>
> Will this justify linux/blktap.h?
>
> One could also revert that ring.h pad space hack.
>
> I'm not passionate about it. If you still disagree, I'll give up and we
> move it elsewhere.
>
> In this case, it could as well go back into drivers/block/blktap, and
> I'll just give up on 'development mode' hacks to verify tapdisk builds
> against the kernel tree altogether.
What sort of "'development mode' hacks"?
> > Where is the canonical definition of this interface stored? In the
> > kernel tree or the hypervisor tree?
>
> You mean blktap.h? This is not a xen driver. I'd call this the canonical
> definition, a reference with what that kernel/driver revision supports,
> that's why I put it there.
>
> It wouldn't belong elsewhere, except for occasionally updated verbatim
> copies in updated blktap sources, to unstress build dependencies.
>
> Daniel
>
> > Ian.
> >
> > > 7 files changed, 142 insertions(+), 100 deletions(-)
> > > create mode 100644 include/linux/blktap.h
> > >
> > > diff --git a/drivers/xen/blktap/blktap.h b/drivers/xen/blktap/blktap.h
> > > index fe63fc9..1318cad 100644
> > > --- a/drivers/xen/blktap/blktap.h
> > > +++ b/drivers/xen/blktap/blktap.h
> > > @@ -6,7 +6,7 @@
> > > #include <linux/cdev.h>
> > > #include <linux/init.h>
> > > #include <linux/scatterlist.h>
> > > -#include <xen/blkif.h>
> > > +#include <linux/blktap.h>
> > >
> > > extern int blktap_debug_level;
> > > extern int blktap_ring_major;
> > > @@ -30,74 +30,26 @@ extern int blktap_device_major;
> > > #define BLKTAP_DEVICE_CLOSED 5
> > > #define BLKTAP_SHUTDOWN_REQUESTED 8
> > >
> > > -/* blktap IOCTLs: */
> > > -#define BLKTAP2_IOCTL_KICK_FE 1
> > > -#define BLKTAP2_IOCTL_ALLOC_TAP 200
> > > -#define BLKTAP2_IOCTL_FREE_TAP 201
> > > -#define BLKTAP2_IOCTL_CREATE_DEVICE 202
> > > -#define BLKTAP2_IOCTL_REMOVE_DEVICE 207
> > > -
> > > -#define BLKTAP2_MAX_MESSAGE_LEN 256
> > > -
> > > -#define BLKTAP2_RING_MESSAGE_CLOSE 3
> > > -
> > > #define BLKTAP_REQUEST_FREE 0
> > > #define BLKTAP_REQUEST_PENDING 1
> > >
> > > -/*
> > > - * The maximum number of requests that can be outstanding at any time
> > > - * is determined by
> > > - *
> > > - * [mmap_alloc * MAX_PENDING_REQS * BLKIF_MAX_SEGMENTS_PER_REQUEST]
> > > - *
> > > - * where mmap_alloc < MAX_DYNAMIC_MEM.
> > > - *
> > > - * TODO:
> > > - * mmap_alloc is initialised to 2 and should be adjustable on the fly via
> > > - * sysfs.
> > > - */
> > > -#define BLK_RING_SIZE __RING_SIZE((struct blkif_sring *)0,
> > > PAGE_SIZE)
> > > -#define MAX_DYNAMIC_MEM BLK_RING_SIZE
> > > -#define MAX_PENDING_REQS BLK_RING_SIZE
> > > -#define MMAP_PAGES (MAX_PENDING_REQS * BLKIF_MAX_SEGMENTS_PER_REQUEST)
> > > -#define MMAP_VADDR(_start, _req, _seg) \
> > > - (_start + \
> > > - ((_req) * BLKIF_MAX_SEGMENTS_PER_REQUEST * PAGE_SIZE) + \
> > > - ((_seg) * PAGE_SIZE))
> > > -
> > > -struct grant_handle_pair {
> > > - grant_handle_t kernel;
> > > - grant_handle_t user;
> > > -};
> > > -#define INVALID_GRANT_HANDLE 0xFFFF
> > > -
> > > -struct blktap_handle {
> > > - unsigned int ring;
> > > - unsigned int device;
> > > - unsigned int minor;
> > > -};
> > > -
> > > -struct blktap_params {
> > > - char name[BLKTAP2_MAX_MESSAGE_LEN];
> > > - unsigned long long capacity;
> > > - unsigned long sector_size;
> > > -};
> > > -
> > > struct blktap_device {
> > > spinlock_t lock;
> > > struct gendisk *gd;
> > > };
> > >
> > > +struct blktap_request;
> > > +
> > > struct blktap_ring {
> > > struct task_struct *task;
> > >
> > > struct vm_area_struct *vma;
> > > - struct blkif_front_ring ring;
> > > + blktap_front_ring_t ring;
> > > unsigned long ring_vstart;
> > > unsigned long user_vstart;
> > >
> > > int n_pending;
> > > - struct blktap_request *pending[MAX_PENDING_REQS];
> > > + struct blktap_request *pending[BLKTAP_RING_SIZE];
> > >
> > > wait_queue_head_t poll_wait;
> > >
> > > @@ -128,8 +80,8 @@ struct blktap_request {
> > > int operation;
> > > struct timeval time;
> > >
> > > - struct scatterlist
> > > sg_table[BLKIF_MAX_SEGMENTS_PER_REQUEST];
> > > - struct page
> > > *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
> > > + struct scatterlist sg_table[BLKTAP_SEGMENT_MAX];
> > > + struct page *pages[BLKTAP_SEGMENT_MAX];
> > > int nr_pages;
> > > };
> > >
> > > @@ -148,7 +100,7 @@ struct blktap {
> > >
> > > wait_queue_head_t remove_wait;
> > > struct work_struct remove_work;
> > > - char name[BLKTAP2_MAX_MESSAGE_LEN];
> > > + char name[BLKTAP_NAME_MAX];
> > >
> > > struct blktap_statistics stats;
> > > };
> > > @@ -189,7 +141,7 @@ void blktap_sysfs_destroy(struct blktap *);
> > > int blktap_device_init(void);
> > > void blktap_device_exit(void);
> > > size_t blktap_device_debug(struct blktap *, char *, size_t);
> > > -int blktap_device_create(struct blktap *, struct blktap_params *);
> > > +int blktap_device_create(struct blktap *, struct blktap_device_info *);
> > > int blktap_device_destroy(struct blktap *);
> > > void blktap_device_destroy_sync(struct blktap *);
> > > void blktap_device_run_queue(struct blktap *);
> > > diff --git a/drivers/xen/blktap/control.c b/drivers/xen/blktap/control.c
> > > index f339bba..57b1a10 100644
> > > --- a/drivers/xen/blktap/control.c
> > > +++ b/drivers/xen/blktap/control.c
> > > @@ -127,19 +127,19 @@ blktap_control_ioctl(struct inode *inode, struct
> > > file *filp,
> > > struct blktap *tap;
> > >
> > > switch (cmd) {
> > > - case BLKTAP2_IOCTL_ALLOC_TAP: {
> > > - struct blktap_handle h;
> > > + case BLKTAP_IOCTL_ALLOC_TAP: {
> > > + struct blktap_info info;
> > > void __user *ptr = (void __user*)arg;
> > >
> > > tap = blktap_control_create_tap();
> > > if (!tap)
> > > return -ENOMEM;
> > >
> > > - h.ring = blktap_ring_major;
> > > - h.device = blktap_device_major;
> > > - h.minor = tap->minor;
> > > + info.ring_major = blktap_ring_major;
> > > + info.bdev_major = blktap_device_major;
> > > + info.ring_minor = tap->minor;
> > >
> > > - if (copy_to_user(ptr, &h, sizeof(h))) {
> > > + if (copy_to_user(ptr, &info, sizeof(info))) {
> > > blktap_control_destroy_tap(tap);
> > > return -EFAULT;
> > > }
> > > @@ -147,7 +147,7 @@ blktap_control_ioctl(struct inode *inode, struct file
> > > *filp,
> > > return 0;
> > > }
> > >
> > > - case BLKTAP2_IOCTL_FREE_TAP: {
> > > + case BLKTAP_IOCTL_FREE_TAP: {
> > > int minor = arg;
> > >
> > > if (minor > MAX_BLKTAP_DEVICE)
> > > diff --git a/drivers/xen/blktap/device.c b/drivers/xen/blktap/device.c
> > > index fce2769..6bb04bd 100644
> > > --- a/drivers/xen/blktap/device.c
> > > +++ b/drivers/xen/blktap/device.c
> > > @@ -186,7 +186,7 @@ blktap_device_make_request(struct blktap *tap, struct
> > > request *rq)
> > > write ? 'w' : 'r', blk_rq_bytes(rq), nsegs);
> > >
> > > request->rq = rq;
> > > - request->operation = write ? BLKIF_OP_WRITE : BLKIF_OP_READ;
> > > + request->operation = write ? BLKTAP_OP_WRITE : BLKTAP_OP_READ;
> > >
> > > err = blktap_request_get_pages(tap, request, nsegs);
> > > if (err)
> > > @@ -276,7 +276,7 @@ blktap_device_do_request(struct request_queue *rq)
> > >
> > > static void
> > > blktap_device_configure(struct blktap *tap,
> > > - struct blktap_params *params)
> > > + struct blktap_device_info *params)
> > > {
> > > struct request_queue *rq;
> > > struct blktap_device *dev = &tap->device;
> > > @@ -297,8 +297,8 @@ blktap_device_configure(struct blktap *tap,
> > > blk_queue_max_segment_size(rq, PAGE_SIZE);
> > >
> > > /* Ensure a merged request will fit in a single I/O ring slot. */
> > > - blk_queue_max_phys_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST);
> > > - blk_queue_max_hw_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST);
> > > + blk_queue_max_phys_segments(rq, BLKTAP_SEGMENT_MAX);
> > > + blk_queue_max_hw_segments(rq, BLKTAP_SEGMENT_MAX);
> > >
> > > /* Make sure buffer addresses are sector-aligned. */
> > > blk_queue_dma_alignment(rq, 511);
> > > @@ -311,7 +311,7 @@ blktap_device_configure(struct blktap *tap,
> > >
> > > static int
> > > blktap_device_validate_params(struct blktap *tap,
> > > - struct blktap_params *params)
> > > + struct blktap_device_info *params)
> > > {
> > > struct device *dev = tap->ring.dev;
> > > int sector_order, name_sz;
> > > @@ -425,7 +425,7 @@ blktap_device_destroy_sync(struct blktap *tap)
> > > }
> > >
> > > int
> > > -blktap_device_create(struct blktap *tap, struct blktap_params *params)
> > > +blktap_device_create(struct blktap *tap, struct blktap_device_info
> > > *params)
> > > {
> > > int minor, err;
> > > struct gendisk *gd;
> > > diff --git a/drivers/xen/blktap/request.c b/drivers/xen/blktap/request.c
> > > index 9bef48c..8cfd6c9 100644
> > > --- a/drivers/xen/blktap/request.c
> > > +++ b/drivers/xen/blktap/request.c
> > > @@ -7,18 +7,18 @@
> > > #include "blktap.h"
> > >
> > > /* max pages per shared pool. just to prevent accidental dos. */
> > > -#define POOL_MAX_PAGES (256*BLKIF_MAX_SEGMENTS_PER_REQUEST)
> > > +#define POOL_MAX_PAGES (256*BLKTAP_SEGMENT_MAX)
> > >
> > > /* default page pool size. when considering to shrink a shared pool,
> > > * note that paused tapdisks may grab a whole lot of pages for a long
> > > * time. */
> > > -#define POOL_DEFAULT_PAGES (2 * MMAP_PAGES)
> > > +#define POOL_DEFAULT_PAGES (2 * BLKTAP_RING_SIZE *
> > > BLKTAP_SEGMENT_MAX)
> > >
> > > /* max number of pages allocatable per request. */
> > > -#define POOL_MAX_REQUEST_PAGES BLKIF_MAX_SEGMENTS_PER_REQUEST
> > > +#define POOL_MAX_REQUEST_PAGES BLKTAP_SEGMENT_MAX
> > >
> > > /* min request structs per pool. These grow dynamically. */
> > > -#define POOL_MIN_REQS BLK_RING_SIZE
> > > +#define POOL_MIN_REQS BLKTAP_RING_SIZE
> > >
> > > static struct kset *pool_set;
> > >
> > > diff --git a/drivers/xen/blktap/ring.c b/drivers/xen/blktap/ring.c
> > > index 6b86be5..9442a64 100644
> > > --- a/drivers/xen/blktap/ring.c
> > > +++ b/drivers/xen/blktap/ring.c
> > > @@ -18,7 +18,7 @@ static struct cdev blktap_ring_cdev;
> > >
> > > static void
> > > blktap_ring_read_response(struct blktap *tap,
> > > - const struct blkif_response *rsp)
> > > + const blktap_ring_rsp_t *rsp)
> > > {
> > > struct blktap_ring *ring = &tap->ring;
> > > struct blktap_request *request;
> > > @@ -27,7 +27,7 @@ blktap_ring_read_response(struct blktap *tap,
> > > request = NULL;
> > >
> > > usr_idx = rsp->id;
> > > - if (usr_idx < 0 || usr_idx >= MAX_PENDING_REQS) {
> > > + if (usr_idx < 0 || usr_idx >= BLKTAP_RING_SIZE) {
> > > err = -ERANGE;
> > > goto invalid;
> > > }
> > > @@ -48,7 +48,7 @@ blktap_ring_read_response(struct blktap *tap,
> > > "request %d [%p] response: %d\n",
> > > request->usr_idx, request, rsp->status);
> > >
> > > - err = rsp->status == BLKIF_RSP_OKAY ? 0 : -EIO;
> > > + err = rsp->status == BLKTAP_RSP_OKAY ? 0 : -EIO;
> > > end_request:
> > > blktap_device_end_request(tap, request, err);
> > > return;
> > > @@ -67,7 +67,7 @@ static void
> > > blktap_read_ring(struct blktap *tap)
> > > {
> > > struct blktap_ring *ring = &tap->ring;
> > > - struct blkif_response rsp;
> > > + blktap_ring_rsp_t rsp;
> > > RING_IDX rc, rp;
> > >
> > > down_read(¤t->mm->mmap_sem);
> > > @@ -90,6 +90,11 @@ blktap_read_ring(struct blktap *tap)
> > > up_read(¤t->mm->mmap_sem);
> > > }
> > >
> > > +#define MMAP_VADDR(_start, _req, _seg) \
> > > + ((_start) + \
> > > + ((_req) * BLKTAP_SEGMENT_MAX * BLKTAP_PAGE_SIZE) + \
> > > + ((_seg) * BLKTAP_PAGE_SIZE))
> > > +
> > > static int blktap_ring_fault(struct vm_area_struct *vma, struct vm_fault
> > > *vmf)
> > > {
> > > return VM_FAULT_SIGBUS;
> > > @@ -102,7 +107,7 @@ blktap_ring_fail_pending(struct blktap *tap)
> > > struct blktap_request *request;
> > > int usr_idx;
> > >
> > > - for (usr_idx = 0; usr_idx < MAX_PENDING_REQS; usr_idx++) {
> > > + for (usr_idx = 0; usr_idx < BLKTAP_RING_SIZE; usr_idx++) {
> > > request = ring->pending[usr_idx];
> > > if (!request)
> > > continue;
> > > @@ -154,7 +159,7 @@ blktap_ring_map_request(struct blktap *tap,
> > > int seg, err = 0;
> > > int write;
> > >
> > > - write = request->operation == BLKIF_OP_WRITE;
> > > + write = request->operation == BLKTAP_OP_WRITE;
> > >
> > > for (seg = 0; seg < request->nr_pages; seg++) {
> > > if (write)
> > > @@ -182,7 +187,7 @@ blktap_ring_unmap_request(struct blktap *tap,
> > >
> > > uaddr = MMAP_VADDR(ring->user_vstart, request->usr_idx, 0);
> > > size = request->nr_pages << PAGE_SHIFT;
> > > - read = request->operation == BLKIF_OP_READ;
> > > + read = request->operation == BLKTAP_OP_READ;
> > >
> > > if (read)
> > > for (seg = 0; seg < request->nr_pages; seg++)
> > > @@ -217,11 +222,11 @@ blktap_ring_make_request(struct blktap *tap)
> > > if (!request)
> > > return ERR_PTR(-ENOMEM);
> > >
> > > - for (usr_idx = 0; usr_idx < BLK_RING_SIZE; usr_idx++)
> > > + for (usr_idx = 0; usr_idx < BLKTAP_RING_SIZE; usr_idx++)
> > > if (!ring->pending[usr_idx])
> > > break;
> > >
> > > - BUG_ON(usr_idx >= BLK_RING_SIZE);
> > > + BUG_ON(usr_idx >= BLKTAP_RING_SIZE);
> > >
> > > request->tap = tap;
> > > request->usr_idx = usr_idx;
> > > @@ -237,7 +242,7 @@ blktap_ring_submit_request(struct blktap *tap,
> > > struct blktap_request *request)
> > > {
> > > struct blktap_ring *ring = &tap->ring;
> > > - struct blkif_request *breq;
> > > + blktap_ring_req_t *breq;
> > > struct scatterlist *sg;
> > > int i, nsecs = 0;
> > >
> > > @@ -248,12 +253,12 @@ blktap_ring_submit_request(struct blktap *tap,
> > >
> > > breq->id = request->usr_idx;
> > > breq->sector_number = blk_rq_pos(request->rq);
> > > - breq->handle = 0;
> > > + breq->__pad = 0;
> > > breq->operation = request->operation;
> > > breq->nr_segments = request->nr_pages;
> > >
> > > blktap_for_each_sg(sg, request, i) {
> > > - struct blkif_request_segment *seg = &breq->seg[i];
> > > + struct blktap_segment *seg = &breq->seg[i];
> > > int first, count;
> > >
> > > count = sg->length >> 9;
> > > @@ -270,12 +275,12 @@ blktap_ring_submit_request(struct blktap *tap,
> > > do_gettimeofday(&request->time);
> > >
> > >
> > > - if (request->operation == BLKIF_OP_WRITE) {
> > > + if (request->operation == BLKTAP_OP_WRITE) {
> > > tap->stats.st_wr_sect += nsecs;
> > > tap->stats.st_wr_req++;
> > > }
> > >
> > > - if (request->operation == BLKIF_OP_READ) {
> > > + if (request->operation == BLKTAP_OP_READ) {
> > > tap->stats.st_rd_sect += nsecs;
> > > tap->stats.st_rd_req++;
> > > }
> > > @@ -327,7 +332,7 @@ blktap_ring_mmap(struct file *filp, struct
> > > vm_area_struct *vma)
> > > {
> > > struct blktap *tap = filp->private_data;
> > > struct blktap_ring *ring = &tap->ring;
> > > - struct blkif_sring *sring;
> > > + blktap_sring_t *sring;
> > > struct page *page = NULL;
> > > int err;
> > >
> > > @@ -384,25 +389,25 @@ blktap_ring_ioctl(struct inode *inode, struct file
> > > *filp,
> > > return -EACCES;
> > >
> > > switch(cmd) {
> > > - case BLKTAP2_IOCTL_KICK_FE:
> > > + case BLKTAP_IOCTL_RESPOND:
> > >
> > > blktap_read_ring(tap);
> > > return 0;
> > >
> > > - case BLKTAP2_IOCTL_CREATE_DEVICE: {
> > > - struct blktap_params params;
> > > + case BLKTAP_IOCTL_CREATE_DEVICE: {
> > > + struct blktap_device_info info;
> > > void __user *ptr = (void *)arg;
> > >
> > > if (!arg)
> > > return -EINVAL;
> > >
> > > - if (copy_from_user(¶ms, ptr, sizeof(params)))
> > > + if (copy_from_user(&info, ptr, sizeof(info)))
> > > return -EFAULT;
> > >
> > > - return blktap_device_create(tap, ¶ms);
> > > + return blktap_device_create(tap, &info);
> > > }
> > >
> > > - case BLKTAP2_IOCTL_REMOVE_DEVICE:
> > > + case BLKTAP_IOCTL_REMOVE_DEVICE:
> > >
> > > return blktap_device_destroy(tap);
> > > }
> > > @@ -482,7 +487,7 @@ blktap_ring_debug(struct blktap *tap, char *buf,
> > > size_t size)
> > > s += snprintf(s, end - s,
> > > "begin pending:%d\n", ring->n_pending);
> > >
> > > - for (usr_idx = 0; usr_idx < MAX_PENDING_REQS; usr_idx++) {
> > > + for (usr_idx = 0; usr_idx < BLKTAP_RING_SIZE; usr_idx++) {
> > > struct blktap_request *request;
> > > struct timeval *time;
> > > int write;
> > > @@ -491,7 +496,7 @@ blktap_ring_debug(struct blktap *tap, char *buf,
> > > size_t size)
> > > if (!request)
> > > continue;
> > >
> > > - write = request->operation == BLKIF_OP_WRITE;
> > > + write = request->operation == BLKTAP_OP_WRITE;
> > > time = &request->time;
> > >
> > > s += snprintf(s, end - s,
> > > diff --git a/drivers/xen/blktap/sysfs.c b/drivers/xen/blktap/sysfs.c
> > > index 7bbfea8..182de9a 100644
> > > --- a/drivers/xen/blktap/sysfs.c
> > > +++ b/drivers/xen/blktap/sysfs.c
> > > @@ -20,7 +20,7 @@ blktap_sysfs_set_name(struct device *dev, struct
> > > device_attribute *attr, const c
> > > if (!tap)
> > > return 0;
> > >
> > > - if (size >= BLKTAP2_MAX_MESSAGE_LEN)
> > > + if (size >= BLKTAP_NAME_MAX)
> > > return -ENAMETOOLONG;
> > >
> > > if (strnlen(buf, size) != size)
> > > @@ -75,8 +75,8 @@ blktap_sysfs_remove_device(struct device *dev,
> > > goto wait;
> > >
> > > if (tap->ring.vma) {
> > > - blkif_sring_t *sring = tap->ring.ring.sring;
> > > - sring->private.tapif_user.msg =
> > > BLKTAP2_RING_MESSAGE_CLOSE;
> > > + blktap_sring_t *sring = tap->ring.ring.sring;
> > > + sring->private.tapif_user.msg = BLKTAP_RING_MESSAGE_CLOSE;
> > > blktap_ring_kick_user(tap);
> > > } else {
> > > INIT_WORK(&tap->remove_work, blktap_sysfs_remove_work);
> > > diff --git a/include/linux/blktap.h b/include/linux/blktap.h
> > > new file mode 100644
> > > index 0000000..ec33429
> > > --- /dev/null
> > > +++ b/include/linux/blktap.h
> > > @@ -0,0 +1,85 @@
> > > +/*
> > > + * Copyright (c) 2011, XenSource Inc.
> > > + * All rights reserved.
> > > + */
> > > +
> > > +#ifndef _LINUX_BLKTAP_H
> > > +#define _LINUX_BLKTAP_H
> > > +
> > > +/*
> > > + * Control
> > > + */
> > > +
> > > +#define BLKTAP_IOCTL_RESPOND 1
> > > +#define BLKTAP_IOCTL_ALLOC_TAP 200
> > > +#define BLKTAP_IOCTL_FREE_TAP 201
> > > +#define BLKTAP_IOCTL_CREATE_DEVICE 202
> > > +#define BLKTAP_IOCTL_REMOVE_DEVICE 207
> > > +
> > > +#define BLKTAP_NAME_MAX 256
> > > +
> > > +struct blktap_info {
> > > + unsigned int ring_major;
> > > + unsigned int bdev_major;
> > > + unsigned int ring_minor;
> > > +};
> > > +
> > > +struct blktap_device_info {
> > > + char name[BLKTAP_NAME_MAX];
> > > + unsigned long long capacity;
> > > + unsigned long sector_size;
> > > +};
> > > +
> > > +/*
> > > + * I/O ring
> > > + */
> > > +
> > > +#ifdef __KERNEL__
> > > +#define BLKTAP_PAGE_SIZE PAGE_SIZE
> > > +#endif
> > > +
> > > +#include <xen/interface/io/ring.h>
> > > +
> > > +typedef struct blktap_ring_request blktap_ring_req_t;
> > > +typedef struct blktap_ring_response blktap_ring_rsp_t;
> > > +
> > > +struct blktap_segment {
> > > + uint32_t __pad;
> > > + uint8_t first_sect;
> > > + uint8_t last_sect;
> > > +};
> > > +
> > > +#define BLKTAP_OP_READ 0
> > > +#define BLKTAP_OP_WRITE 1
> > > +
> > > +#define BLKTAP_SEGMENT_MAX 11
> > > +
> > > +struct blktap_ring_request {
> > > + uint8_t operation;
> > > + uint8_t nr_segments;
> > > + uint16_t __pad;
> > > + uint64_t id;
> > > + uint64_t sector_number;
> > > + struct blktap_segment seg[BLKTAP_SEGMENT_MAX];
> > > +};
> > > +
> > > +#define BLKTAP_RSP_EOPNOTSUPP -2
> > > +#define BLKTAP_RSP_ERROR -1
> > > +#define BLKTAP_RSP_OKAY 0
> > > +
> > > +struct blktap_ring_response {
> > > + uint64_t id;
> > > + uint8_t operation;
> > > + int16_t status;
> > > +};
> > > +
> > > +DEFINE_RING_TYPES(blktap, struct blktap_ring_request, struct
> > > blktap_ring_response);
> > > +#define BLKTAP_RING_SIZE __CONST_RING_SIZE(blktap, BLKTAP_PAGE_SIZE)
> > > +
> > > +/*
> > > + * Ring messages (DEPRECATED)
> > > + */
> > > +
> > > +#define BLKTAP_RING_MESSAGE_CLOSE 3
> > > +
> > > +#endif /* _LINUX_BLKTAP_H */
> > > --
> > > 1.7.0.4
> > >
> > >
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-devel
> >
> >
>
>
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