This code doesn't compile, is marked as DANGEROUS, and is said
to be removed when block drivers use grant tables. So let's remove it.
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
linux-2.6-xen-sparse/drivers/xen/Kconfig | 13
linux-2.6-xen-sparse/drivers/xen/Makefile | 1
linux-2.6-xen-sparse/drivers/xen/blktap/Makefile | 3
linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c | 900 --------------------
linux-2.6-xen-sparse/drivers/xen/blktap/common.h | 100 --
linux-2.6-xen-sparse/drivers/xen/blktap/interface.c | 134 --
linux-2.6-xen-sparse/drivers/xen/blktap/xenbus.c | 223 ----
7 files changed, 1374 deletions(-)
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/Kconfig
--- a/linux-2.6-xen-sparse/drivers/xen/Kconfig Thu Jun 08 16:51:39 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/Kconfig Fri Jun 09 01:24:49 2006 -0400
@@ -84,19 +84,6 @@ config XEN_BLKDEV_BACKEND
block devices to other guests via a high-performance shared-memory
interface.
-config XEN_BLKDEV_TAP_BE
- tristate "Block Tap support for backend driver (DANGEROUS)"
- depends on XEN_BLKDEV_BACKEND
- default n
- help
- If you intend to use the block tap driver, the backend domain will
- not know the domain id of the real frontend, and so will not be able
- to map its data pages. This modifies the backend to attempt to map
- from both the tap domain and the real frontend. This presents a
- security risk, and so should ONLY be used for development
- with the blktap. This option will be removed as the block drivers
are
- modified to use grant tables.
-
config XEN_NETDEV_BACKEND
tristate "Network-device backend driver"
depends on XEN_BACKEND && NET
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/Makefile
--- a/linux-2.6-xen-sparse/drivers/xen/Makefile Thu Jun 08 16:51:39 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/Makefile Fri Jun 09 01:24:49 2006 -0400
@@ -12,6 +12,5 @@ obj-$(CONFIG_XEN_TPMDEV_BACKEND) += tpmb
obj-$(CONFIG_XEN_TPMDEV_BACKEND) += tpmback/
obj-$(CONFIG_XEN_BLKDEV_FRONTEND) += blkfront/
obj-$(CONFIG_XEN_NETDEV_FRONTEND) += netfront/
-obj-$(CONFIG_XEN_BLKDEV_TAP) += blktap/
obj-$(CONFIG_XEN_PCIDEV_BACKEND) += pciback/
obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += pcifront/
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/blktap/Makefile
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/Makefile Thu Jun 08 16:51:39
2006 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +0,0 @@
-
-obj-y := xenbus.o interface.o blktap.o
-
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c Thu Jun 08 16:51:39
2006 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,900 +0,0 @@
-/******************************************************************************
- * arch/xen/drivers/blkif/blktap/blktap.c
- *
- * This is a modified version of the block backend driver that remaps requests
- * to a user-space memory region. It is intended to be used to write
- * application-level servers that provide block interfaces to client VMs.
- */
-
-#include <linux/kernel.h>
-#include <linux/spinlock.h>
-#include <xen/balloon.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/miscdevice.h>
-#include <linux/errno.h>
-#include <linux/major.h>
-#include <linux/gfp.h>
-#include <linux/poll.h>
-#include <asm/tlbflush.h>
-#include "common.h"
-
-/* Only one process may open /dev/xen/blktap at any time. */
-static unsigned long blktap_dev_inuse;
-unsigned long blktap_ring_ok; /* make this ring->state */
-
-/* Rings up to user space. */
-static blkif_front_ring_t blktap_ufe_ring;
-
-/* for poll: */
-static wait_queue_head_t blktap_wait;
-
-/* current switching mode */
-static unsigned long blktap_mode;
-
-/* local prototypes */
-static int blktap_read_ufe_ring(void);
-
-
-/* /dev/xen/blktap resides at device number major=10, minor=200 */
-#define BLKTAP_MINOR 202
-
-/* blktap IOCTLs: */
-#define BLKTAP_IOCTL_KICK_FE 1
-#define BLKTAP_IOCTL_KICK_BE 2 /* currently unused */
-#define BLKTAP_IOCTL_SETMODE 3
-#define BLKTAP_IOCTL_PRINT_IDXS 100
-
-/* blktap switching modes: (Set with BLKTAP_IOCTL_SETMODE) */
-#define BLKTAP_MODE_PASSTHROUGH 0x00000000 /* default */
-#define BLKTAP_MODE_INTERCEPT_FE 0x00000001
-#define BLKTAP_MODE_INTERCEPT_BE 0x00000002 /* unimp. */
-#define BLKTAP_MODE_COPY_FE 0x00000004 /* unimp. */
-#define BLKTAP_MODE_COPY_BE 0x00000008 /* unimp. */
-#define BLKTAP_MODE_COPY_FE_PAGES 0x00000010 /* unimp. */
-#define BLKTAP_MODE_COPY_BE_PAGES 0x00000020 /* unimp. */
-
-#define BLKTAP_MODE_INTERPOSE \
- (BLKTAP_MODE_INTERCEPT_FE | BLKTAP_MODE_INTERCEPT_BE)
-
-#define BLKTAP_MODE_COPY_BOTH \
- (BLKTAP_MODE_COPY_FE | BLKTAP_MODE_COPY_BE)
-
-#define BLKTAP_MODE_COPY_BOTH_PAGES \
- (BLKTAP_MODE_COPY_FE_PAGES | BLKTAP_MODE_COPY_BE_PAGES)
-
-static inline int BLKTAP_MODE_VALID(unsigned long arg)
-{
- return ((arg == BLKTAP_MODE_PASSTHROUGH ) ||
- (arg == BLKTAP_MODE_INTERCEPT_FE) ||
- (arg == BLKTAP_MODE_INTERPOSE ));
-/*
- return (
- ( arg == BLKTAP_MODE_PASSTHROUGH ) ||
- ( arg == BLKTAP_MODE_INTERCEPT_FE ) ||
- ( arg == BLKTAP_MODE_INTERCEPT_BE ) ||
- ( arg == BLKTAP_MODE_INTERPOSE ) ||
- ( (arg & ~BLKTAP_MODE_COPY_FE_PAGES) == BLKTAP_MODE_COPY_FE ) ||
- ( (arg & ~BLKTAP_MODE_COPY_BE_PAGES) == BLKTAP_MODE_COPY_BE ) ||
- ( (arg & ~BLKTAP_MODE_COPY_BOTH_PAGES) == BLKTAP_MODE_COPY_BOTH )
- );
-*/
-}
-
-
-/******************************************************************
- * MMAP REGION
- */
-
-/*
- * We use a big chunk of address space to map in-flight requests into,
- * and export this region up to user-space. See the comments in blkback
- * about this -- the two must be kept in sync if the tap is used as a
- * passthrough.
- */
-
-#define MAX_PENDING_REQS 64
-#define BATCH_PER_DOMAIN 16
-
-/* immediately before the mmap area, we have a bunch of pages reserved
- * for shared memory rings.
- */
-#define RING_PAGES 1 /* Front */
-
-/* Where things are inside the device mapping. */
-struct vm_area_struct *blktap_vma = NULL;
-unsigned long mmap_vstart; /* Kernel pages for mapping in data. */
-unsigned long rings_vstart; /* start of mmaped vma */
-unsigned long user_vstart; /* start of user mappings */
-
-#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))
-
-/*
- * Each outstanding request that we've passed to the lower device layers has a
- * 'pending_req' allocated to it. Each buffer_head that completes decrements
- * the pendcnt towards zero. When it hits zero, the specified domain has a
- * response queued for it, with the saved 'id' passed back.
- */
-typedef struct {
- blkif_t *blkif;
- unsigned long id;
- int nr_pages;
- atomic_t pendcnt;
- unsigned short operation;
- int status;
-} pending_req_t;
-
-/*
- * We can't allocate pending_req's in order, since they may complete out of
- * order. We therefore maintain an allocation ring. This ring also indicates
- * when enough work has been passed down -- at that point the allocation ring
- * will be empty.
- */
-static pending_req_t pending_reqs[MAX_PENDING_REQS];
-static unsigned char pending_ring[MAX_PENDING_REQS];
-static DEFINE_SPINLOCK(pend_prod_lock);
-/* NB. We use a different index type to differentiate from shared blk rings. */
-typedef unsigned int PEND_RING_IDX;
-#define MASK_PEND_IDX(_i) ((_i)&(MAX_PENDING_REQS-1))
-static PEND_RING_IDX pending_prod, pending_cons;
-#define NR_PENDING_REQS (MAX_PENDING_REQS - pending_prod + pending_cons)
-
-/* Requests passing through the tap to the backend hijack the id field
- * in the request message. In it we put the AR index _AND_ the fe domid.
- * the domid is used by the backend to map the pages properly.
- */
-
-static inline unsigned long MAKE_ID(domid_t fe_dom, PEND_RING_IDX idx)
-{
- return ((fe_dom << 16) | MASK_PEND_IDX(idx));
-}
-
-extern inline PEND_RING_IDX ID_TO_IDX(unsigned long id)
-{
- return (PEND_RING_IDX)(id & 0x0000ffff);
-}
-
-extern inline domid_t ID_TO_DOM(unsigned long id)
-{
- return (domid_t)(id >> 16);
-}
-
-
-
-/******************************************************************
- * GRANT HANDLES
- */
-
-/* When using grant tables to map a frame for device access then the
- * handle returned must be used to unmap the frame. This is needed to
- * drop the ref count on the frame.
- */
-struct grant_handle_pair
-{
- grant_handle_t kernel;
- grant_handle_t user;
-};
-static struct grant_handle_pair pending_grant_handles[MMAP_PAGES];
-#define pending_handle(_idx, _i) \
- (pending_grant_handles[((_idx) * BLKIF_MAX_SEGMENTS_PER_REQUEST) + (_i)])
-#define BLKTAP_INVALID_HANDLE(_g) \
- (((_g->kernel) == 0xFFFF) && ((_g->user) == 0xFFFF))
-#define BLKTAP_INVALIDATE_HANDLE(_g) do { \
- (_g)->kernel = 0xFFFF; (_g)->user = 0xFFFF; \
- } while(0)
-
-
-/******************************************************************
- * BLKTAP VM OPS
- */
-
-static struct page *blktap_nopage(struct vm_area_struct *vma,
- unsigned long address,
- int *type)
-{
- /*
- * if the page has not been mapped in by the driver then generate
- * a SIGBUS to the domain.
- */
- force_sig(SIGBUS, current);
-
- return 0;
-}
-
-struct vm_operations_struct blktap_vm_ops = {
- .nopage = blktap_nopage,
-};
-
-/******************************************************************
- * BLKTAP FILE OPS
- */
-
-static int blktap_open(struct inode *inode, struct file *filp)
-{
- blkif_sring_t *sring;
-
- if (test_and_set_bit(0, &blktap_dev_inuse))
- return -EBUSY;
-
- /* Allocate the fe ring. */
- sring = (blkif_sring_t *)get_zeroed_page(GFP_KERNEL);
- if (sring == NULL)
- return -ENOMEM;
-
- SetPageReserved(virt_to_page(sring));
-
- SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&blktap_ufe_ring, sring, PAGE_SIZE);
-
- return 0;
-}
-
-static int blktap_release(struct inode *inode, struct file *filp)
-{
- blktap_dev_inuse = 0;
- blktap_ring_ok = 0;
-
- /* Free the ring page. */
- ClearPageReserved(virt_to_page(blktap_ufe_ring.sring));
- free_page((unsigned long) blktap_ufe_ring.sring);
-
- /* Clear any active mappings and free foreign map table */
- if (blktap_vma != NULL) {
- zap_page_range(
- blktap_vma, blktap_vma->vm_start,
- blktap_vma->vm_end - blktap_vma->vm_start, NULL);
- blktap_vma = NULL;
- }
-
- return 0;
-}
-
-
-/* Note on mmap:
- * We need to map pages to user space in a way that will allow the block
- * subsystem set up direct IO to them. This couldn't be done before, because
- * there isn't really a sane way to translate a user virtual address down to a
- * physical address when the page belongs to another domain.
- *
- * My first approach was to map the page in to kernel memory, add an entry
- * for it in the physical frame list (using alloc_lomem_region as in blkback)
- * and then attempt to map that page up to user space. This is disallowed
- * by xen though, which realizes that we don't really own the machine frame
- * underlying the physical page.
- *
- * The new approach is to provide explicit support for this in xen linux.
- * The VMA now has a flag, VM_FOREIGN, to indicate that it contains pages
- * mapped from other vms. vma->vm_private_data is set up as a mapping
- * from pages to actual page structs. There is a new clause in get_user_pages
- * that does the right thing for this sort of mapping.
- */
-static int blktap_mmap(struct file *filp, struct vm_area_struct *vma)
-{
- int size;
- struct page **map;
- int i;
-
- DPRINTK(KERN_ALERT "blktap mmap (%lx, %lx)\n",
- vma->vm_start, vma->vm_end);
-
- vma->vm_flags |= VM_RESERVED;
- vma->vm_ops = &blktap_vm_ops;
-
- size = vma->vm_end - vma->vm_start;
- if (size != ((MMAP_PAGES + RING_PAGES) << PAGE_SHIFT)) {
- printk(KERN_INFO
- "blktap: you _must_ map exactly %d pages!\n",
- MMAP_PAGES + RING_PAGES);
- return -EAGAIN;
- }
-
- size >>= PAGE_SHIFT;
- DPRINTK(KERN_INFO "blktap: 2 rings + %d pages.\n", size-1);
-
- rings_vstart = vma->vm_start;
- user_vstart = rings_vstart + (RING_PAGES << PAGE_SHIFT);
-
- /* Map the ring pages to the start of the region and reserve it. */
-
- /* not sure if I really need to do this... */
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
- if (remap_pfn_range(vma, vma->vm_start,
- __pa(blktap_ufe_ring.sring) >> PAGE_SHIFT,
- PAGE_SIZE, vma->vm_page_prot)) {
- WPRINTK("Mapping user ring failed!\n");
- goto fail;
- }
-
- /* Mark this VM as containing foreign pages, and set up mappings. */
- map = kmalloc(((vma->vm_end - vma->vm_start) >> PAGE_SHIFT)
- * sizeof(struct page_struct*),
- GFP_KERNEL);
- if (map == NULL) {
- WPRINTK("Couldn't alloc VM_FOREIGH map.\n");
- goto fail;
- }
-
- for (i = 0; i < ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT); i++)
- map[i] = NULL;
-
- vma->vm_private_data = map;
- vma->vm_flags |= VM_FOREIGN;
-
- blktap_vma = vma;
- blktap_ring_ok = 1;
-
- return 0;
- fail:
- /* Clear any active mappings. */
- zap_page_range(vma, vma->vm_start,
- vma->vm_end - vma->vm_start, NULL);
-
- return -ENOMEM;
-}
-
-static int blktap_ioctl(struct inode *inode, struct file *filp,
- unsigned int cmd, unsigned long arg)
-{
- switch(cmd) {
- case BLKTAP_IOCTL_KICK_FE: /* There are fe messages to process. */
- return blktap_read_ufe_ring();
-
- case BLKTAP_IOCTL_SETMODE:
- if (BLKTAP_MODE_VALID(arg)) {
- blktap_mode = arg;
- /* XXX: may need to flush rings here. */
- printk(KERN_INFO "blktap: set mode to %lx\n", arg);
- return 0;
- }
- case BLKTAP_IOCTL_PRINT_IDXS:
- {
- //print_fe_ring_idxs();
- WPRINTK("User Rings: \n-----------\n");
- WPRINTK("UF: rsp_cons: %2d, req_prod_prv: %2d "
- "| req_prod: %2d, rsp_prod: %2d\n",
- blktap_ufe_ring.rsp_cons,
- blktap_ufe_ring.req_prod_pvt,
- blktap_ufe_ring.sring->req_prod,
- blktap_ufe_ring.sring->rsp_prod);
-
- }
- }
- return -ENOIOCTLCMD;
-}
-
-static unsigned int blktap_poll(struct file *file, poll_table *wait)
-{
- poll_wait(file, &blktap_wait, wait);
- if (blktap_ufe_ring.req_prod_pvt != blktap_ufe_ring.sring->req_prod) {
- flush_tlb_all();
- RING_PUSH_REQUESTS(&blktap_ufe_ring);
- return POLLIN | POLLRDNORM;
- }
-
- return 0;
-}
-
-void blktap_kick_user(void)
-{
- /* blktap_ring->req_prod = blktap_req_prod; */
- wake_up_interruptible(&blktap_wait);
-}
-
-static struct file_operations blktap_fops = {
- .owner = THIS_MODULE,
- .poll = blktap_poll,
- .ioctl = blktap_ioctl,
- .open = blktap_open,
- .release = blktap_release,
- .mmap = blktap_mmap,
-};
-
-
-
-static int do_block_io_op(blkif_t *blkif, int max_to_do);
-static void dispatch_rw_block_io(blkif_t *blkif, blkif_request_t *req);
-static void make_response(blkif_t *blkif, unsigned long id,
- unsigned short op, int st);
-
-
-static void fast_flush_area(int idx, int nr_pages)
-{
- struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST*2];
- unsigned int i, op = 0;
- struct grant_handle_pair *handle;
- uint64_t ptep;
- int ret;
-
- for ( i = 0; i < nr_pages; i++)
- {
- handle = &pending_handle(idx, i);
- if (BLKTAP_INVALID_HANDLE(handle))
- continue;
-
- gnttab_set_unmap_op(&unmap[op],
- MMAP_VADDR(mmap_vstart, idx, i),
- GNTMAP_host_map, handle->kernel);
- op++;
-
- if (create_lookup_pte_addr(
- blktap_vma->vm_mm,
- MMAP_VADDR(user_vstart, idx, i),
- &ptep) !=0) {
- DPRINTK("Couldn't get a pte addr!\n");
- return;
- }
- gnttab_set_unmap_grnat_ref(&unmap[op], ptep,
- GNTMAP_host_map |
- GNTMAP_application_map |
- GNTMAP_contains_pte, handle->user);
- op++;
-
- BLKTAP_INVALIDATE_HANDLE(handle);
- }
-
- ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, op);
- BUG_ON(ret);
-
- if (blktap_vma != NULL)
- zap_page_range(blktap_vma,
- MMAP_VADDR(user_vstart, idx, 0),
- nr_pages << PAGE_SHIFT, NULL);
-}
-
-/******************************************************************
- * BLOCK-DEVICE SCHEDULER LIST MAINTENANCE
- */
-
-static struct list_head blkio_schedule_list;
-static spinlock_t blkio_schedule_list_lock;
-
-static int __on_blkdev_list(blkif_t *blkif)
-{
- return blkif->blkdev_list.next != NULL;
-}
-
-static void remove_from_blkdev_list(blkif_t *blkif)
-{
- unsigned long flags;
-
- if (!__on_blkdev_list(blkif))
- return;
-
- spin_lock_irqsave(&blkio_schedule_list_lock, flags);
- if (__on_blkdev_list(blkif)) {
- list_del(&blkif->blkdev_list);
- blkif->blkdev_list.next = NULL;
- blkif_put(blkif);
- }
- spin_unlock_irqrestore(&blkio_schedule_list_lock, flags);
-}
-
-static void add_to_blkdev_list_tail(blkif_t *blkif)
-{
- unsigned long flags;
-
- if (__on_blkdev_list(blkif))
- return;
-
- spin_lock_irqsave(&blkio_schedule_list_lock, flags);
- if (!__on_blkdev_list(blkif) && (blkif->status == CONNECTED)) {
- list_add_tail(&blkif->blkdev_list, &blkio_schedule_list);
- blkif_get(blkif);
- }
- spin_unlock_irqrestore(&blkio_schedule_list_lock, flags);
-}
-
-
-/******************************************************************
- * SCHEDULER FUNCTIONS
- */
-
-static DECLARE_WAIT_QUEUE_HEAD(blkio_schedule_wait);
-
-static int blkio_schedule(void *arg)
-{
- DECLARE_WAITQUEUE(wq, current);
-
- blkif_t *blkif;
- struct list_head *ent;
-
- daemonize("xenblkd");
-
- for (;;) {
- /* Wait for work to do. */
- add_wait_queue(&blkio_schedule_wait, &wq);
- set_current_state(TASK_INTERRUPTIBLE);
- if ((NR_PENDING_REQS == MAX_PENDING_REQS) ||
- list_empty(&blkio_schedule_list))
- schedule();
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&blkio_schedule_wait, &wq);
-
- /* Queue up a batch of requests. */
- while ((NR_PENDING_REQS < MAX_PENDING_REQS) &&
- !list_empty(&blkio_schedule_list)) {
- ent = blkio_schedule_list.next;
- blkif = list_entry(ent, blkif_t, blkdev_list);
- blkif_get(blkif);
- remove_from_blkdev_list(blkif);
- if (do_block_io_op(blkif, BATCH_PER_DOMAIN))
- add_to_blkdev_list_tail(blkif);
- blkif_put(blkif);
- }
- }
-}
-
-static void maybe_trigger_blkio_schedule(void)
-{
- /*
- * Needed so that two processes, who together make the following
- * predicate true, don't both read stale values and evaluate the
- * predicate incorrectly. Incredibly unlikely to stall the scheduler
- * on the x86, but...
- */
- smp_mb();
-
- if ((NR_PENDING_REQS < (MAX_PENDING_REQS/2)) &&
- !list_empty(&blkio_schedule_list))
- wake_up(&blkio_schedule_wait);
-}
-
-
-
-/******************************************************************
- * COMPLETION CALLBACK -- Called as bh->b_end_io()
- */
-
-
-static int blktap_read_ufe_ring(void)
-{
- /* This is called to read responses from the UFE ring. */
-
- RING_IDX i, j, rp;
- blkif_response_t *resp;
- blkif_t *blkif;
- int pending_idx;
- pending_req_t *pending_req;
- unsigned long flags;
-
- /* if we are forwarding from UFERring to FERing */
- if (blktap_mode & BLKTAP_MODE_INTERCEPT_FE) {
-
- /* for each outstanding message on the UFEring */
- rp = blktap_ufe_ring.sring->rsp_prod;
- rmb();
-
- for (i = blktap_ufe_ring.rsp_cons; i != rp; i++) {
- resp = RING_GET_RESPONSE(&blktap_ufe_ring, i);
- pending_idx = MASK_PEND_IDX(ID_TO_IDX(resp->id));
- pending_req = &pending_reqs[pending_idx];
-
- blkif = pending_req->blkif;
- for (j = 0; j < pending_req->nr_pages; j++) {
- unsigned long vaddr;
- struct page **map = blktap_vma->vm_private_data;
- int offset;
-
- vaddr = MMAP_VADDR(user_vstart, pending_idx,
j);
- offset = (vaddr - blktap_vma->vm_start) >>
PAGE_SHIFT;
-
- //ClearPageReserved(virt_to_page(vaddr));
- ClearPageReserved((struct page *)map[offset]);
- map[offset] = NULL;
- }
-
- fast_flush_area(pending_idx, pending_req->nr_pages);
- make_response(blkif, pending_req->id, resp->operation,
- resp->status);
- blkif_put(pending_req->blkif);
- spin_lock_irqsave(&pend_prod_lock, flags);
- pending_ring[MASK_PEND_IDX(pending_prod++)] =
pending_idx;
- spin_unlock_irqrestore(&pend_prod_lock, flags);
- }
- blktap_ufe_ring.rsp_cons = i;
- maybe_trigger_blkio_schedule();
- }
- return 0;
-}
-
-
-/******************************************************************************
- * NOTIFICATION FROM GUEST OS.
- */
-
-irqreturn_t blkif_be_int(int irq, void *dev_id, struct pt_regs *regs)
-{
- blkif_t *blkif = dev_id;
- add_to_blkdev_list_tail(blkif);
- maybe_trigger_blkio_schedule();
- return IRQ_HANDLED;
-}
-
-
-
-/******************************************************************
- * DOWNWARD CALLS -- These interface with the block-device layer proper.
- */
-
-static int do_block_io_op(blkif_t *blkif, int max_to_do)
-{
- blkif_back_ring_t *blk_ring = &blkif->blk_ring;
- blkif_request_t *req;
- RING_IDX i, rp;
- int more_to_do = 0;
-
- rp = blk_ring->sring->req_prod;
- rmb(); /* Ensure we see queued requests up to 'rp'. */
-
- for (i = blk_ring->req_cons;
- (i != rp) && !RING_REQUEST_CONS_OVERFLOW(blk_ring, i);
- i++ ) {
- if ((max_to_do-- == 0) ||
- (NR_PENDING_REQS == MAX_PENDING_REQS)) {
- more_to_do = 1;
- break;
- }
-
- req = RING_GET_REQUEST(blk_ring, i);
- switch (req->operation) {
- case BLKIF_OP_READ:
- case BLKIF_OP_WRITE:
- dispatch_rw_block_io(blkif, req);
- break;
-
- default:
- DPRINTK("error: unknown block io operation [%d]\n",
- req->operation);
- make_response(blkif, req->id, req->operation,
- BLKIF_RSP_ERROR);
- break;
- }
- }
-
- blk_ring->req_cons = i;
- blktap_kick_user();
-
- return more_to_do;
-}
-
-static void dispatch_rw_block_io(blkif_t *blkif, blkif_request_t *req)
-{
- blkif_request_t *target;
- int i, pending_idx = pending_ring[MASK_PEND_IDX(pending_cons)];
- pending_req_t *pending_req;
- struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST*2];
- int op, ret;
- unsigned int nseg;
- int retval;
-
- /* Check that number of segments is sane. */
- nseg = req->nr_segments;
- if (unlikely(nseg == 0) ||
- unlikely(nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) {
- DPRINTK("Bad number of segments in request (%d)\n", nseg);
- goto bad_descriptor;
- }
-
- /* Make sure userspace is ready. */
- if (!blktap_ring_ok) {
- DPRINTK("blktap: ring not ready for requests!\n");
- goto bad_descriptor;
- }
-
-
- if (RING_FULL(&blktap_ufe_ring)) {
- WPRINTK("blktap: fe_ring is full, can't add "
- "(very broken!).\n");
- goto bad_descriptor;
- }
-
- flush_cache_all(); /* a noop on intel... */
-
- /* Map the foreign pages directly in to the application */
- op = 0;
- for (i = 0; i < req->nr_segments; i++) {
-
- unsigned long uvaddr;
- unsigned long kvaddr;
- uint64_t ptep;
- uint32_t flags;
-
- uvaddr = MMAP_VADDR(user_vstart, pending_idx, i);
- kvaddr = MMAP_VADDR(mmap_vstart, pending_idx, i);
-
- flags = GNTMAP_host_map;
- /* This needs a bit more thought in terms of interposition:
- * If we want to be able to modify pages during write using
- * grant table mappings, the guest will either need to allow
- * it, or we'll need to incur a copy. Bit of an fbufs moment.
;) */
- if (req->operation == BLKIF_OP_WRITE)
- flags |= GNTMAP_readonly;
- /* Map the remote page to kernel. */
- gnttab_set_map_op(&map[op], kvaddr, flags, req->seg[i].gref,
- blkif->domid);
- op++;
-
- /* Now map it to user. */
- ret = create_lookup_pte_addr(blktap_vma->vm_mm, uvaddr, &ptep);
- if (ret) {
- DPRINTK("Couldn't get a pte addr!\n");
- fast_flush_area(pending_idx, req->nr_segments);
- goto bad_descriptor;
- }
-
- flags = GNTMAP_host_map | GNTMAP_application_map
- | GNTMAP_contains_pte;
- /* Above interposition comment applies here as well. */
- if (req->operation == BLKIF_OP_WRITE)
- flags |= GNTMAP_readonly;
- gnttab_set_map_op(&map[op], ptep, flags, req->seg[i].gref,
- blkif->domid);
- op++;
- }
-
- retval = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map, op);
- BUG_ON(retval);
-
- op = 0;
- for (i = 0; i < (req->nr_segments*2); i += 2) {
- unsigned long uvaddr;
- unsigned long kvaddr;
- unsigned long offset;
- int cancel = 0;
-
- uvaddr = MMAP_VADDR(user_vstart, pending_idx, i/2);
- kvaddr = MMAP_VADDR(mmap_vstart, pending_idx, i/2);
-
- if (unlikely(map[i].status)) {
- DPRINTK("Error on kernel grant mapping (%d)\n",
- map[i].status);
- ret = map[i].status;
- cancel = 1;
- }
-
- if (unlikely(map[i+1].status)) {
- DPRINTK("Error on user grant mapping (%d)\n",
- map[i+1].status);
- ret = map[i+1].status;
- cancel = 1;
- }
-
- if (cancel) {
- fast_flush_area(pending_idx, req->nr_segments);
- goto bad_descriptor;
- }
-
- /* Set the necessary mappings in p2m and in the VM_FOREIGN
- * vm_area_struct to allow user vaddr -> struct page lookups
- * to work. This is needed for direct IO to foreign pages. */
- set_phys_to_machine(__pa(kvaddr) >> PAGE_SHIFT,
- FOREIGN_FRAME(map[i].dev_bus_addr >>
PAGE_SHIFT));
-
- offset = (uvaddr - blktap_vma->vm_start) >> PAGE_SHIFT;
- ((struct page **)blktap_vma->vm_private_data)[offset] =
- pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
-
- /* Save handles for unmapping later. */
- pending_handle(pending_idx, i/2).kernel = map[i].handle;
- pending_handle(pending_idx, i/2).user = map[i+1].handle;
- }
-
- /* Mark mapped pages as reserved: */
- for (i = 0; i < req->nr_segments; i++) {
- unsigned long kvaddr;
- kvaddr = MMAP_VADDR(mmap_vstart, pending_idx, i);
- SetPageReserved(pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT));
- }
-
- pending_req = &pending_reqs[pending_idx];
- pending_req->blkif = blkif;
- pending_req->id = req->id;
- pending_req->operation = req->operation;
- pending_req->status = BLKIF_RSP_OKAY;
- pending_req->nr_pages = nseg;
- req->id = MAKE_ID(blkif->domid, pending_idx);
- //atomic_set(&pending_req->pendcnt, nbio);
- pending_cons++;
- blkif_get(blkif);
-
- /* Finally, write the request message to the user ring. */
- target = RING_GET_REQUEST(&blktap_ufe_ring,
- blktap_ufe_ring.req_prod_pvt);
- memcpy(target, req, sizeof(*req));
- blktap_ufe_ring.req_prod_pvt++;
- return;
-
- bad_descriptor:
- make_response(blkif, req->id, req->operation, BLKIF_RSP_ERROR);
-}
-
-
-
-/******************************************************************
- * MISCELLANEOUS SETUP / TEARDOWN / DEBUGGING
- */
-
-
-static void make_response(blkif_t *blkif, unsigned long id,
- unsigned short op, int st)
-{
- blkif_response_t *resp;
- unsigned long flags;
- blkif_back_ring_t *blk_ring = &blkif->blk_ring;
-
- /* Place on the response ring for the relevant domain. */
- spin_lock_irqsave(&blkif->blk_ring_lock, flags);
- resp = RING_GET_RESPONSE(blk_ring, blk_ring->rsp_prod_pvt);
- resp->id = id;
- resp->operation = op;
- resp->status = st;
- wmb(); /* Ensure other side can see the response fields. */
- blk_ring->rsp_prod_pvt++;
- RING_PUSH_RESPONSES(blk_ring);
- spin_unlock_irqrestore(&blkif->blk_ring_lock, flags);
-
- /* Kick the relevant domain. */
- notify_remote_via_irq(blkif->irq);
-}
-
-static struct miscdevice blktap_miscdev = {
- .minor = BLKTAP_MINOR,
- .name = "blktap",
- .fops = &blktap_fops,
- .devfs_name = "misc/blktap",
-};
-
-void blkif_deschedule(blkif_t *blkif)
-{
- remove_from_blkdev_list(blkif);
-}
-
-static int __init blkif_init(void)
-{
- int i, j, err;
- struct page *page;
-
- blkif_interface_init();
-
- page = balloon_alloc_empty_page_range(MMAP_PAGES);
- BUG_ON(page == NULL);
- mmap_vstart = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
-
- pending_cons = 0;
- pending_prod = MAX_PENDING_REQS;
- memset(pending_reqs, 0, sizeof(pending_reqs));
- for ( i = 0; i < MAX_PENDING_REQS; i++ )
- pending_ring[i] = i;
-
- spin_lock_init(&blkio_schedule_list_lock);
- INIT_LIST_HEAD(&blkio_schedule_list);
-
- i = kernel_thread(blkio_schedule, 0, CLONE_FS | CLONE_FILES);
- BUG_ON(i<0);
-
- blkif_xenbus_init();
-
- for (i = 0; i < MAX_PENDING_REQS ; i++)
- for (j = 0; j < BLKIF_MAX_SEGMENTS_PER_REQUEST; j++)
- BLKTAP_INVALIDATE_HANDLE(&pending_handle(i, j));
-
- err = misc_register(&blktap_miscdev);
- if (err != 0) {
- printk(KERN_ALERT "Couldn't register /dev/misc/blktap (%d)\n",
- err);
- return err;
- }
-
- init_waitqueue_head(&blktap_wait);
-
- return 0;
-}
-
-__initcall(blkif_init);
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/blktap/common.h
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/common.h Thu Jun 08 16:51:39
2006 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,100 +0,0 @@
-
-#ifndef __BLKIF__BACKEND__COMMON_H__
-#define __BLKIF__BACKEND__COMMON_H__
-
-#include <linux/config.h>
-#include <linux/version.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/slab.h>
-#include <linux/blkdev.h>
-#include <linux/vmalloc.h>
-#include <asm/io.h>
-#include <asm/setup.h>
-#include <asm/pgalloc.h>
-#include <xen/evtchn.h>
-#include <asm/hypervisor.h>
-#include <xen/interface/io/blkif.h>
-#include <xen/interface/io/ring.h>
-#include <xen/gnttab.h>
-#include <xen/driver_util.h>
-
-#define DPRINTK(_f, _a...) pr_debug("(file=%s, line=%d) " _f, \
- __FILE__ , __LINE__ , ## _a )
-
-#define WPRINTK(fmt, args...) printk(KERN_WARNING "blk_tap: " fmt, ##args)
-
-struct vbd {
- blkif_vdev_t handle; /* what the domain refers to this vbd as */
- unsigned char readonly; /* Non-zero -> read-only */
- unsigned char type; /* VDISK_xxx */
- u32 pdevice; /* phys device that this vbd maps to */
- struct block_device *bdev;
-};
-
-typedef struct blkif_st {
- /* Unique identifier for this interface. */
- domid_t domid;
- unsigned int handle;
- /* Physical parameters of the comms window. */
- unsigned int evtchn;
- unsigned int irq;
- /* Comms information. */
- blkif_back_ring_t blk_ring;
- struct vm_struct *blk_ring_area;
- /* VBDs attached to this interface. */
- struct vbd vbd;
- /* Private fields. */
- enum { DISCONNECTED, CONNECTED } status;
-#ifdef CONFIG_XEN_BLKDEV_TAP_BE
- /* Is this a blktap frontend */
- unsigned int is_blktap;
-#endif
- struct list_head blkdev_list;
- spinlock_t blk_ring_lock;
- atomic_t refcnt;
-
- struct work_struct free_work;
-
- grant_handle_t shmem_handle;
- grant_ref_t shmem_ref;
-} blkif_t;
-
-blkif_t *alloc_blkif(domid_t domid);
-void free_blkif_callback(blkif_t *blkif);
-int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn);
-
-#define blkif_get(_b) (atomic_inc(&(_b)->refcnt))
-#define blkif_put(_b) \
- do { \
- if ( atomic_dec_and_test(&(_b)->refcnt) ) \
- free_blkif_callback(_b); \
- } while (0)
-
-/* Create a vbd. */
-int vbd_create(blkif_t *blkif, blkif_vdev_t vdevice, u32 pdevice,
- int readonly);
-void vbd_free(struct vbd *vbd);
-
-unsigned long vbd_size(struct vbd *vbd);
-unsigned int vbd_info(struct vbd *vbd);
-unsigned long vbd_secsize(struct vbd *vbd);
-
-struct phys_req {
- unsigned short dev;
- unsigned short nr_sects;
- struct block_device *bdev;
- blkif_sector_t sector_number;
-};
-
-int vbd_translate(struct phys_req *req, blkif_t *blkif, int operation);
-
-void blkif_interface_init(void);
-
-void blkif_deschedule(blkif_t *blkif);
-
-void blkif_xenbus_init(void);
-
-irqreturn_t blkif_be_int(int irq, void *dev_id, struct pt_regs *regs);
-
-#endif /* __BLKIF__BACKEND__COMMON_H__ */
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/blktap/interface.c
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/interface.c Thu Jun 08
16:51:39 2006 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,134 +0,0 @@
-/******************************************************************************
- * arch/xen/drivers/blkif/backend/interface.c
- *
- * Block-device interface management.
- *
- * Copyright (c) 2004, Keir Fraser
- */
-
-#include "common.h"
-#include <xen/evtchn.h>
-
-static kmem_cache_t *blkif_cachep;
-
-blkif_t *alloc_blkif(domid_t domid)
-{
- blkif_t *blkif;
-
- blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL);
- if (!blkif)
- return ERR_PTR(-ENOMEM);
-
- memset(blkif, 0, sizeof(*blkif));
- blkif->domid = domid;
- blkif->status = DISCONNECTED;
- spin_lock_init(&blkif->blk_ring_lock);
- atomic_set(&blkif->refcnt, 1);
-
- return blkif;
-}
-
-static int map_frontend_page(blkif_t *blkif, unsigned long shared_page)
-{
- struct gnttab_map_grant_ref op;
- int ret;
-
- gnttab_set_map_op(&op, (unsigned long)blkif->blk_ring_area->addr,
- GNTMAP_host_map, shared_page, blkif->domid);
-
- lock_vm_area(blkif->blk_ring_area);
- ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1);
- unlock_vm_area(blkif->blk_ring_area);
- BUG_ON(ret);
-
- if (op.status) {
- DPRINTK(" Grant table operation failure !\n");
- return op.status;
- }
-
- blkif->shmem_ref = shared_page;
- blkif->shmem_handle = op.handle;
-
- return 0;
-}
-
-static void unmap_frontend_page(blkif_t *blkif)
-{
- struct gnttab_unmap_grant_ref op;
- int ret;
-
- gnttab_set_unmap_op(&op, (unsigned long)blkif->blk_ring_area->addr,
- GNTMAP_host_map, blkif->shmem_handle);
-
- lock_vm_area(blkif->blk_ring_area);
- ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1);
- unlock_vm_area(blkif->blk_ring_area);
- BUG_ON(ret);
-}
-
-int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
-{
- blkif_sring_t *sring;
- int err;
- struct evtchn_bind_interdomain bind_interdomain;
-
- if ((blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL)
- return -ENOMEM;
-
- err = map_frontend_page(blkif, shared_page);
- if (err) {
- free_vm_area(blkif->blk_ring_area);
- return err;
- }
-
- bind_interdomain.remote_dom = blkif->domid;
- bind_interdomain.remote_port = evtchn;
-
- err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
- &bind_interdomain);
- if (err) {
- unmap_frontend_page(blkif);
- free_vm_area(blkif->blk_ring_area);
- return err;
- }
-
- blkif->evtchn = bind_interdomain.local_port;
-
- sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
- BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
-
- blkif->irq = bind_evtchn_to_irqhandler(
- blkif->evtchn, blkif_be_int, 0, "blkif-backend", blkif);
-
- blkif->status = CONNECTED;
-
- return 0;
-}
-
-static void free_blkif(void *arg)
-{
- blkif_t *blkif = (blkif_t *)arg;
-
- if (blkif->irq)
- unbind_from_irqhandler(blkif->irq, blkif);
-
- if (blkif->blk_ring.sring) {
- unmap_frontend_page(blkif);
- free_vm_area(blkif->blk_ring_area);
- blkif->blk_ring.sring = NULL;
- }
-
- kmem_cache_free(blkif_cachep, blkif);
-}
-
-void free_blkif_callback(blkif_t *blkif)
-{
- INIT_WORK(&blkif->free_work, free_blkif, (void *)blkif);
- schedule_work(&blkif->free_work);
-}
-
-void __init blkif_interface_init(void)
-{
- blkif_cachep = kmem_cache_create(
- "blkif_cache", sizeof(blkif_t), 0, 0, NULL, NULL);
-}
diff -r 4f1e39ec05d6 linux-2.6-xen-sparse/drivers/xen/blktap/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/xenbus.c Thu Jun 08 16:51:39
2006 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,223 +0,0 @@
-/* Xenbus code for blkif tap
-
- A Warfield.
-
- Hastily modified from the oroginal backend code:
-
- Copyright (C) 2005 Rusty Russell <rusty@xxxxxxxxxxxxxxx>
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-*/
-
-#include <stdarg.h>
-#include <linux/module.h>
-#include <xen/xenbus.h>
-#include "common.h"
-
-struct backend_info
-{
- struct xenbus_device *dev;
-
- /* our communications channel */
- blkif_t *blkif;
-
- long int frontend_id;
-
- /* watch back end for changes */
- struct xenbus_watch backend_watch;
-
- /* watch front end for changes */
- struct xenbus_watch watch;
- char *frontpath;
-};
-
-static int blkback_remove(struct xenbus_device *dev)
-{
- struct backend_info *be = dev->data;
-
- if (be->watch.node)
- unregister_xenbus_watch(&be->watch);
- unregister_xenbus_watch(&be->backend_watch);
- if (be->blkif)
- blkif_put(be->blkif);
- kfree(be->frontpath);
- kfree(be);
- return 0;
-}
-
-/* Front end tells us frame. */
-static void frontend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
-{
- unsigned long ring_ref;
- unsigned int evtchn;
- int err;
- struct backend_info *be
- = container_of(watch, struct backend_info, watch);
-
- /* If other end is gone, delete ourself. */
- if (vec && !xenbus_exists(be->frontpath, "")) {
- xenbus_rm(be->dev->nodename, "");
- device_unregister(&be->dev->dev);
- return;
- }
- if (be->blkif == NULL || be->blkif->status == CONNECTED)
- return;
-
- err = xenbus_gather(be->frontpath, "ring-ref", "%lu", &ring_ref,
- "event-channel", "%u", &evtchn, NULL);
- if (err) {
- xenbus_dev_error(be->dev, err,
- "reading %s/ring-ref and event-channel",
- be->frontpath);
- return;
- }
-
- /* Map the shared frame, irq etc. */
- err = blkif_map(be->blkif, ring_ref, evtchn);
- if (err) {
- xenbus_dev_error(be->dev, err, "mapping ring-ref %lu port %u",
- ring_ref, evtchn);
- goto abort;
- }
-
- xenbus_dev_ok(be->dev);
-
- return;
-
-abort:
- xenbus_transaction_end(1);
-}
-
-/*
- Setup supplies physical device.
- We provide event channel and device details to front end.
- Frontend supplies shared frame and event channel.
- */
-static void backend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
-{
- int err;
- char *p;
- long int handle;
- struct backend_info *be
- = container_of(watch, struct backend_info, backend_watch);
- struct xenbus_device *dev = be->dev;
-
- if (be->blkif == NULL) {
- /* Front end dir is a number, which is used as the handle. */
- p = strrchr(be->frontpath, '/') + 1;
- handle = simple_strtoul(p, NULL, 0);
-
- be->blkif = alloc_blkif(be->frontend_id);
- if (IS_ERR(be->blkif)) {
- err = PTR_ERR(be->blkif);
- be->blkif = NULL;
- xenbus_dev_error(dev, err, "creating block interface");
- return;
- }
-
- /* Pass in NULL node to skip exist test. */
- frontend_changed(&be->watch, NULL, 0);
- }
-}
-
-static int blkback_probe(struct xenbus_device *dev,
- const struct xenbus_device_id *id)
-{
- struct backend_info *be;
- char *frontend;
- int err;
-
- be = kzalloc(sizeof(*be), GFP_KERNEL);
- if (!be) {
- xenbus_dev_error(dev, -ENOMEM, "allocating backend structure");
- return -ENOMEM;
- }
-
- frontend = NULL;
- err = xenbus_gather(dev->nodename,
- "frontend-id", "%li", &be->frontend_id,
- "frontend", NULL, &frontend,
- NULL);
- if (XENBUS_EXIST_ERR(err))
- goto free_be;
- if (err < 0) {
- xenbus_dev_error(dev, err,
- "reading %s/frontend or frontend-id",
- dev->nodename);
- goto free_be;
- }
- if (strlen(frontend) == 0 || !xenbus_exists(frontend, "")) {
- /* If we can't get a frontend path and a frontend-id,
- * then our bus-id is no longer valid and we need to
- * destroy the backend device.
- */
- err = -ENOENT;
- goto free_be;
- }
-
- be->dev = dev;
- be->backend_watch.node = dev->nodename;
- be->backend_watch.callback = backend_changed;
- /* Registration implicitly fires backend_changed once */
- err = register_xenbus_watch(&be->backend_watch);
- if (err) {
- be->backend_watch.node = NULL;
- xenbus_dev_error(dev, err, "adding backend watch on %s",
- dev->nodename);
- goto free_be;
- }
-
- be->frontpath = frontend;
- be->watch.node = be->frontpath;
- be->watch.callback = frontend_changed;
- err = register_xenbus_watch(&be->watch);
- if (err) {
- be->watch.node = NULL;
- xenbus_dev_error(dev, err,
- "adding frontend watch on %s",
- be->frontpath);
- goto free_be;
- }
-
- dev->data = be;
- return 0;
-
- free_be:
- if (be->backend_watch.node)
- unregister_xenbus_watch(&be->backend_watch);
- kfree(frontend);
- kfree(be);
- return err;
-}
-
-static struct xenbus_device_id blkback_ids[] = {
- { "vbd" },
- { "" }
-};
-
-static struct xenbus_driver blkback = {
- .name = "vbd",
- .owner = THIS_MODULE,
- .ids = blkback_ids,
- .probe = blkback_probe,
- .remove = blkback_remove,
-};
-
-void blkif_xenbus_init(void)
-{
- xenbus_register_backend(&blkback);
-}
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