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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC][PATCH] Use ioemu block drivers through blktap
> +static int connect_qemu(blkif_t *blkif)
> +{
> + char *rdctldev, *wrctldev;
> +
> + if (asprintf(&rdctldev, BLKTAP_CTRL_DIR "/qemu-read-%d",
> + blkif->domid) < 0)
> + return -1;
> +
> + if (asprintf(&wrctldev, BLKTAP_CTRL_DIR "/qemu-write-%d",
> + blkif->domid) < 0) {
> + free(rdctldev);
> + return -1;
> + }
> +
> + DPRINTF("Using qemu blktap pipe: %s\n", rdctldev);
> +
> + blkif->fds[READ] = open_ctrl_socket(wrctldev);
> + blkif->fds[WRITE] = open_ctrl_socket(rdctldev);
How about freeing the data here once?
> +
> + if (blkif->fds[READ] == -1 || blkif->fds[WRITE] == -1) {
> + free(rdctldev);
> + free(wrctldev);
And then this is not needed.
> + return -1;
> + }
> +
> + DPRINTF("Attached to qemu blktap pipes\n");
> + free(rdctldev);
> + free(wrctldev);
Nor these two lines above.
Thought looking at the 'connect_tapdisk' you are using 'goto'
there, why not emulate the same behavior in this function?
> + return 0;
> +}
> +
> +/* Launch tapdisk instance */
> +static int connect_tapdisk(blkif_t *blkif, int minor)
> +{
> + char *rdctldev = NULL, *wrctldev = NULL;
> + int ret = -1;
> +
> + DPRINTF("tapdisk process does not exist:\n");
> +
> + if (asprintf(&rdctldev,
> + "%s/tapctrlread%d", BLKTAP_CTRL_DIR, minor) == -1)
> + goto fail;
> +
> + if (asprintf(&wrctldev,
> + "%s/tapctrlwrite%d", BLKTAP_CTRL_DIR, minor) == -1)
> + goto fail;
> +
> + blkif->fds[READ] = open_ctrl_socket(rdctldev);
> + blkif->fds[WRITE] = open_ctrl_socket(wrctldev);
> +
> + if (blkif->fds[READ] == -1 || blkif->fds[WRITE] == -1)
> + goto fail;
> +
> + /*launch the new process*/
> + DPRINTF("Launching process, CMDLINE [tapdisk %s %s]\n",
> + wrctldev, rdctldev);
> +
> + if (launch_tapdisk(wrctldev, rdctldev) == -1) {
> + DPRINTF("Unable to fork, cmdline: [tapdisk %s %s]\n",
> + wrctldev, rdctldev);
> + goto fail;
> + }
> +
> + ret = 0;
> +
> +fail:
> + if (rdctldev)
> + free(rdctldev);
> +
> + if (wrctldev)
> + free(wrctldev);
> +
> + return ret;
> +}
> +
> int blktapctrl_new_blkif(blkif_t *blkif)
> {
> blkif_info_t *blk;
> @@ -524,30 +600,14 @@ int blktapctrl_new_blkif(blkif_t *blkif)
> blkif->cookie = next_cookie++;
>
> if (!exist) {
> - DPRINTF("Process does not exist:\n");
> - if (asprintf(&rdctldev,
> - "%s/tapctrlread%d", BLKTAP_CTRL_DIR,
> minor) == -1)
> - goto fail;
> - if (asprintf(&wrctldev,
> - "%s/tapctrlwrite%d", BLKTAP_CTRL_DIR,
> minor) == -1) {
> - free(rdctldev);
> - goto fail;
> + if (type == DISK_TYPE_IOEMU) {
> + if (connect_qemu(blkif))
> + goto fail;
> + } else {
> + if (connect_tapdisk(blkif, minor))
> + goto fail;
> }
> - blkif->fds[READ] = open_ctrl_socket(rdctldev);
> - blkif->fds[WRITE] = open_ctrl_socket(wrctldev);
> -
> - if (blkif->fds[READ] == -1 || blkif->fds[WRITE] == -1)
> - goto fail;
> -
> - /*launch the new process*/
> - DPRINTF("Launching process, CMDLINE [tapdisk %s
> %s]\n",wrctldev, rdctldev);
> - if (launch_tapdisk(wrctldev, rdctldev) == -1) {
> - DPRINTF("Unable to fork, cmdline: [tapdisk %s
> %s]\n",wrctldev, rdctldev);
> - goto fail;
> - }
> -
> - free(rdctldev);
> - free(wrctldev);
> +
> } else {
> DPRINTF("Process exists!\n");
> blkif->fds[READ] = exist->fds[READ];
> diff -r f33328217eee tools/blktap/drivers/tapdisk.h
> --- a/tools/blktap/drivers/tapdisk.h Mon Mar 10 22:51:57 2008 +0000
> +++ b/tools/blktap/drivers/tapdisk.h Thu Mar 13 13:00:18 2008 +0100
> @@ -167,6 +167,7 @@ extern struct tap_disk tapdisk_qcow2;
> #define DISK_TYPE_RAM 3
> #define DISK_TYPE_QCOW 4
> #define DISK_TYPE_QCOW2 5
> +#define DISK_TYPE_IOEMU 6
>
>
> /*Define Individual Disk Parameters here */
> @@ -227,6 +228,16 @@ static disk_info_t qcow2_disk = {
> 0,
> #ifdef TAPDISK
> &tapdisk_qcow2,
> +#endif
> +};
> +
> +static disk_info_t ioemu_disk = {
> + DISK_TYPE_IOEMU,
> + "ioemu disk",
> + "ioemu",
> + 0,
> +#ifdef TAPDISK
> + NULL
> #endif
> };
>
> @@ -238,6 +249,7 @@ static disk_info_t *dtypes[] = {
> &ram_disk,
> &qcow_disk,
> &qcow2_disk,
> + &ioemu_disk,
> };
>
> typedef struct driver_list_entry {
> diff -r f33328217eee tools/blktap/lib/blktaplib.h
> --- a/tools/blktap/lib/blktaplib.h Mon Mar 10 22:51:57 2008 +0000
> +++ b/tools/blktap/lib/blktaplib.h Thu Mar 13 13:00:18 2008 +0100
> @@ -221,15 +221,5 @@ int xs_fire_next_watch(struct xs_handle
> ((_req) * BLKIF_MAX_SEGMENTS_PER_REQUEST * getpagesize()) + \
> ((_seg) * getpagesize()))
>
> -/* Defines that are only used by library clients */
> -
> -#ifndef __COMPILING_BLKTAP_LIB
> -
> -static char *blkif_op_name[] = {
> - [BLKIF_OP_READ] = "READ",
> - [BLKIF_OP_WRITE] = "WRITE",
> -};
> -
> -#endif /* __COMPILING_BLKTAP_LIB */
>
> #endif /* __BLKTAPLIB_H__ */
> diff -r f33328217eee tools/ioemu/Makefile.target
> --- a/tools/ioemu/Makefile.target Mon Mar 10 22:51:57 2008 +0000
> +++ b/tools/ioemu/Makefile.target Thu Mar 13 13:00:18 2008 +0100
> @@ -17,6 +17,7 @@ VPATH=$(SRC_PATH):$(TARGET_PATH):$(SRC_P
> VPATH=$(SRC_PATH):$(TARGET_PATH):$(SRC_PATH)/hw:$(SRC_PATH)/audio
> CPPFLAGS+=-I. -I.. -I$(TARGET_PATH) -I$(SRC_PATH)
> CPPFLAGS+= -I$(XEN_ROOT)/tools/libxc
> +CPPFLAGS+= -I$(XEN_ROOT)/tools/blktap/lib
> CPPFLAGS+= -I$(XEN_ROOT)/tools/xenstore
> CPPFLAGS+= -I$(XEN_ROOT)/tools/include
> ifdef CONFIG_DARWIN_USER
> @@ -429,6 +430,7 @@ VL_OBJS+= usb-uhci.o smbus_eeprom.o
> VL_OBJS+= usb-uhci.o smbus_eeprom.o
> VL_OBJS+= piix4acpi.o
> VL_OBJS+= xenstore.o
> +VL_OBJS+= xen_blktap.o
> VL_OBJS+= xen_platform.o
> VL_OBJS+= xen_machine_fv.o
> VL_OBJS+= xen_machine_pv.o
> diff -r f33328217eee tools/ioemu/hw/xen_machine_pv.c
> --- a/tools/ioemu/hw/xen_machine_pv.c Mon Mar 10 22:51:57 2008 +0000
> +++ b/tools/ioemu/hw/xen_machine_pv.c Thu Mar 13 13:00:18 2008 +0100
> @@ -26,6 +26,9 @@
> #include "xen_console.h"
> #include "xenfb.h"
>
> +extern void init_blktap(void);
> +
> +
> /* The Xen PV machine currently provides
> * - a virtual framebuffer
> * - ....
> @@ -40,6 +43,10 @@ static void xen_init_pv(uint64_t ram_siz
> {
> struct xenfb *xenfb;
> extern int domid;
> +
> +
> + /* Initialize tapdisk client */
> + init_blktap();
>
> /* Connect to text console */
> if (serial_hds[0]) {
> diff -r f33328217eee tools/ioemu/vl.c
> --- a/tools/ioemu/vl.c Mon Mar 10 22:51:57 2008 +0000
> +++ b/tools/ioemu/vl.c Thu Mar 13 13:00:18 2008 +0100
> @@ -6270,6 +6270,12 @@ void qemu_system_powerdown_request(void)
> powerdown_requested = 1;
> if (cpu_single_env)
> cpu_interrupt(cpu_single_env, CPU_INTERRUPT_EXIT);
> +}
> +
> +static void qemu_sighup_handler(int signal)
> +{
> + fprintf(stderr, "Received SIGHUP, terminating.\n");
> + exit(0);
> }
>
> void main_loop_wait(int timeout)
> @@ -7980,7 +7986,7 @@ int main(int argc, char **argv)
>
> #ifndef CONFIG_STUBDOM
> /* Unblock SIGTERM and SIGHUP, which may have been blocked by the caller
> */
> - signal(SIGHUP, SIG_DFL);
> + signal(SIGHUP, qemu_sighup_handler);
> sigemptyset(&set);
> sigaddset(&set, SIGTERM);
> sigaddset(&set, SIGHUP);
> diff -r f33328217eee tools/python/xen/xend/server/BlktapController.py
> --- a/tools/python/xen/xend/server/BlktapController.py Mon Mar 10
> 22:51:57 2008 +0000
> +++ b/tools/python/xen/xend/server/BlktapController.py Thu Mar 13
> 13:00:18 2008 +0100
> @@ -13,7 +13,9 @@ blktap_disk_types = [
> 'vmdk',
> 'ram',
> 'qcow',
> - 'qcow2'
> + 'qcow2',
> +
> + 'ioemu'
Why add the extra \n ?
> ]
>
> class BlktapController(BlkifController):
> diff -r f33328217eee tools/ioemu/hw/xen_blktap.c
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/tools/ioemu/hw/xen_blktap.c Thu Mar 13 13:00:18 2008 +0100
> @@ -0,0 +1,688 @@
> +/* xen_blktap.c
> + *
> + * Interface to blktapctrl to allow use of qemu block drivers with blktap.
> + * This file is based on tools/blktap/drivers/tapdisk.c
> + *
> + * Copyright (c) 2005 Julian Chesterfield and Andrew Warfield.
> + * Copyright (c) 2008 Kevin Wolf
> + */
> +
> +/*
> + * There are several communication channels which are used by this interface:
> + *
> + * - A pair of pipes for receiving and sending general control messages
> + * (qemu-read-N and qemu-writeN in /var/run/tap, where N is the domain
> ID).
> + * These control messages are handled by handle_blktap_ctrlmsg().
> + *
> + * - One file descriptor per attached disk (/dev/xen/blktapN) for disk
> + * specific control messages. A callback is triggered on this fd if there
> + * is a new IO request. The callback function is handle_blktap_iomsg().
> + *
> + * - A shared ring for each attached disk containing the actual IO
> requests
> + * and responses. Whenever handle_blktap_iomsg() is triggered it
> processes
> + * the requests on this ring.
> + */
> +
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <sys/mman.h>
> +#include <sys/ioctl.h>
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <errno.h>
> +#include <stdlib.h>
> +
> +#include "vl.h"
> +#include "blktaplib.h"
> +#include "xen_blktap.h"
> +#include "block_int.h"
> +
> +#define MSG_SIZE 4096
> +
> +#define BLKTAP_CTRL_DIR "/var/run/tap"
> +
> +/* If enabled, print debug messages to stderr */
> +#if 1
> +#define DPRINTF(_f, _a...) fprintf(stderr, __FILE__ ":%d: " _f, __LINE__,
> ##_a)
> +#else
> +#define DPRINTF(_f, _a...) ((void)0)
> +#endif
> +
> +#if 1
> +#define ASSERT(_p) \
> + if ( !(_p) ) { DPRINTF("Assertion '%s' failed, line %d, file %s", #_p , \
You probably want \n at the end.
> + __LINE__, __FILE__); *(int*)0=0; }
> +#else
> +#define ASSERT(_p) ((void)0)
> +#endif
> +
> +
> +extern int domid;
> +
> +int read_fd;
> +int write_fd;
> +
> +static pid_t process;
> +fd_list_entry_t *fd_start = NULL;
> +
> +static void handle_blktap_iomsg(void* private);
> +
> +struct aiocb_info {
> + struct td_state *s;
> + uint64_t sector;
> + int nr_secs;
> + int idx;
> + long i;
> +};
> +
> +static void unmap_disk(struct td_state *s)
> +{
> + tapdev_info_t *info = s->ring_info;
> + fd_list_entry_t *entry;
> +
> + bdrv_close(s->bs);
> +
> + if (info != NULL && info->mem > 0)
> + munmap(info->mem, getpagesize() * BLKTAP_MMAP_REGION_SIZE);
> +
> + entry = s->fd_entry;
> + *entry->pprev = entry->next;
> + if (entry->next)
> + entry->next->pprev = entry->pprev;
> +
> + qemu_set_fd_handler2(info->fd, NULL, NULL, NULL, NULL);
> + close(info->fd);
> +
> + free(s->fd_entry);
> + free(s->blkif);
> + free(s->ring_info);
> + free(s);
> +
> + return;
> +}
> +
> +static inline fd_list_entry_t *add_fd_entry(int tap_fd, struct td_state *s)
> +{
> + fd_list_entry_t **pprev, *entry;
> +
> + DPRINTF("Adding fd_list_entry\n");
> +
> + /*Add to linked list*/
> + s->fd_entry = entry = malloc(sizeof(fd_list_entry_t));
> + entry->tap_fd = tap_fd;
> + entry->s = s;
> + entry->next = NULL;
> +
> + pprev = &fd_start;
> + while (*pprev != NULL)
> + pprev = &(*pprev)->next;
> +
> + *pprev = entry;
> + entry->pprev = pprev;
> +
> + return entry;
> +}
> +
> +static inline struct td_state *get_state(int cookie)
> +{
> + fd_list_entry_t *ptr;
> +
> + ptr = fd_start;
> + while (ptr != NULL) {
> + if (ptr->cookie == cookie) return ptr->s;
> + ptr = ptr->next;
> + }
> + return NULL;
> +}
> +
> +static struct td_state *state_init(void)
> +{
> + int i;
> + struct td_state *s;
> + blkif_t *blkif;
> +
> + s = malloc(sizeof(struct td_state));
Would it make sense to zero out the allocated memory?
> + blkif = s->blkif = malloc(sizeof(blkif_t));
> + s->ring_info = calloc(1, sizeof(tapdev_info_t));
> +
> + for (i = 0; i < MAX_REQUESTS; i++) {
> + blkif->pending_list[i].secs_pending = 0;
> + blkif->pending_list[i].submitting = 0;
> + }
> +
> + return s;
> +}
> +
> +static int map_new_dev(struct td_state *s, int minor)
> +{
> + int tap_fd;
> + tapdev_info_t *info = s->ring_info;
> + char *devname;
> + fd_list_entry_t *ptr;
> + int page_size;
> +
> + if (asprintf(&devname,"%s/%s%d", BLKTAP_DEV_DIR, BLKTAP_DEV_NAME,
> minor) == -1)
> + return -1;
> + tap_fd = open(devname, O_RDWR);
> + if (tap_fd == -1)
> + {
> + DPRINTF("open failed on dev %s!",devname);
You forgot to include \n above.
> + goto fail;
> + }
> + info->fd = tap_fd;
> +
> + /*Map the shared memory*/
> + page_size = getpagesize();
> + info->mem = mmap(0, page_size * BLKTAP_MMAP_REGION_SIZE,
> + PROT_READ | PROT_WRITE, MAP_SHARED, info->fd, 0);
> + if ((long int)info->mem == -1)
> + {
> + DPRINTF("mmap failed on dev %s!\n",devname);
> + goto fail;
> + }
> +
> + /* assign the rings to the mapped memory */
> + info->sring = (blkif_sring_t *)((unsigned long)info->mem);
> + BACK_RING_INIT(&info->fe_ring, info->sring, page_size);
> +
> + info->vstart =
> + (unsigned long)info->mem + (BLKTAP_RING_PAGES * page_size);
> +
> + ioctl(info->fd, BLKTAP_IOCTL_SENDPID, process );
> + ioctl(info->fd, BLKTAP_IOCTL_SETMODE, BLKTAP_MODE_INTERPOSE );
> + free(devname);
> +
> + /*Update the fd entry*/
> + ptr = fd_start;
> + while (ptr != NULL) {
> + if (s == ptr->s) {
> + ptr->tap_fd = tap_fd;
> +
> + /* Setup fd_handler for qemu main loop */
> + DPRINTF("set tap_fd = %d\n", tap_fd);
> + qemu_set_fd_handler2(tap_fd, NULL,
> &handle_blktap_iomsg, NULL, s);
> +
> + break;
> + }
> + ptr = ptr->next;
> + }
> +
> +
> + DPRINTF("map_new_dev = %d\n", minor);
> + return minor;
> +
> + fail:
> + free(devname);
> + return -1;
> +}
> +
> +static int open_disk(struct td_state *s, char *path, int readonly)
> +{
> + struct disk_id id;
> + BlockDriverState* bs;
> +
> + DPRINTF("Opening %s\n", path);
> + bs = calloc(sizeof(*bs), 1);
Are the arguments swapped?
> +
> + memset(&id, 0, sizeof(struct disk_id));
> +
> + if (bdrv_open(bs, path, 0) != 0) {
> + fprintf(stderr, "Could not open image file %s\n", path);
> + return -ENOMEM;
> + }
> +
> + s->bs = bs;
> + s->flags = readonly ? TD_RDONLY : 0;
> + s->size = bs->total_sectors;
> + s->sector_size = 512;
> +
> + s->info = ((s->flags & TD_RDONLY) ? VDISK_READONLY : 0);
> +
> + return 0;
> +}
> +
> +static inline int write_rsp_to_ring(struct td_state *s, blkif_response_t
> *rsp)
Why bother with a return of int when you always return 0?
> +{
> + tapdev_info_t *info = s->ring_info;
> + blkif_response_t *rsp_d;
> +
> + rsp_d = RING_GET_RESPONSE(&info->fe_ring, info->fe_ring.rsp_prod_pvt);
> + memcpy(rsp_d, rsp, sizeof(blkif_response_t));
> + info->fe_ring.rsp_prod_pvt++;
> +
> + return 0;
> +}
> +
> +static inline void kick_responses(struct td_state *s)
> +{
> + tapdev_info_t *info = s->ring_info;
> +
> + if (info->fe_ring.rsp_prod_pvt != info->fe_ring.sring->rsp_prod)
> + {
> + RING_PUSH_RESPONSES(&info->fe_ring);
> + ioctl(info->fd, BLKTAP_IOCTL_KICK_FE);
> + }
> +}
> +
> +static int send_responses(struct td_state *s, int res,
> + uint64_t sector, int nr_secs, int idx, void *private)
> +{
> + pending_req_t *preq;
> + blkif_request_t *req;
> + int responses_queued = 0;
> + blkif_t *blkif = s->blkif;
> + int secs_done = nr_secs;
> +
> + if ( (idx > MAX_REQUESTS-1) )
> + {
> + DPRINTF("invalid index returned(%u)!\n", idx);
> + return 0;
> + }
> + preq = &blkif->pending_list[idx];
> + req = &preq->req;
> +
> + preq->secs_pending -= secs_done;
> +
> + if (res == -EBUSY && preq->submitting)
> + return -EBUSY; /* propagate -EBUSY back to higher layers */
> + if (res)
> + preq->status = BLKIF_RSP_ERROR;
> +
> + if (!preq->submitting && preq->secs_pending == 0)
> + {
> + blkif_request_t tmp;
> + blkif_response_t *rsp;
> +
> + tmp = preq->req;
> + rsp = (blkif_response_t *)req;
> +
> + rsp->id = tmp.id;
> + rsp->operation = tmp.operation;
> + rsp->status = preq->status;
> +
> + write_rsp_to_ring(s, rsp);
> + responses_queued++;
> +
> + kick_responses(s);
> + }
> +
> + return responses_queued;
> +}
> +
> +static void qemu_send_responses(void* opaque, int ret)
> +{
> + struct aiocb_info* info = opaque;
> +
> + if (ret != 0) {
> + DPRINTF("ERROR: ret = %d (%s)\n", ret, strerror(-ret));
> + }
> +
> + send_responses(info->s, ret, info->sector, info->nr_secs,
> + info->idx, (void*) info->i);
> + free(info);
> +}
> +
> +/**
> + * Callback function for the IO message pipe. Reads requests from the ring
> + * and processes them (call qemu read/write functions).
> + *
> + * The private parameter points to the struct td_state representing the
> + * disk the request is targeted at.
> + */
> +static void handle_blktap_iomsg(void* private)
> +{
> + struct td_state* s = private;
> +
> + RING_IDX rp, j, i;
> + blkif_request_t *req;
> + int idx, nsects, ret;
> + uint64_t sector_nr;
> + uint8_t *page;
> + blkif_t *blkif = s->blkif;
> + tapdev_info_t *info = s->ring_info;
> + int page_size = getpagesize();
> +
> + struct aiocb_info *aiocb_info;
> +
> + if (info->fe_ring.sring == NULL) {
> + DPRINTF(" sring == NULL, ignoring IO request\n");
> + return;
> + }
> +
> + rp = info->fe_ring.sring->req_prod;
> + xen_rmb();
> +
> + for (j = info->fe_ring.req_cons; j != rp; j++)
> + {
> + int start_seg = 0;
> +
> + req = NULL;
> + req = RING_GET_REQUEST(&info->fe_ring, j);
> + ++info->fe_ring.req_cons;
> +
> + if (req == NULL)
> + continue;
> +
> + idx = req->id;
> +
> + ASSERT(blkif->pending_list[idx].secs_pending == 0);
> + memcpy(&blkif->pending_list[idx].req, req, sizeof(*req));
> + blkif->pending_list[idx].status = BLKIF_RSP_OKAY;
> + blkif->pending_list[idx].submitting = 1;
> + sector_nr = req->sector_number;
> +
> + /* Don't allow writes on readonly devices */
> + if ((s->flags & TD_RDONLY) &&
> + (req->operation == BLKIF_OP_WRITE)) {
> + blkif->pending_list[idx].status = BLKIF_RSP_ERROR;
> + goto send_response;
> + }
> +
> + for (i = start_seg; i < req->nr_segments; i++) {
> + nsects = req->seg[i].last_sect -
> + req->seg[i].first_sect + 1;
> +
> + if ((req->seg[i].last_sect >= page_size >> 9) ||
> + (nsects <= 0))
> + continue;
> +
> + page = (uint8_t*) MMAP_VADDR(info->vstart,
> + (unsigned long)req->id, i);
> + page += (req->seg[i].first_sect << SECTOR_SHIFT);
> +
> + if (sector_nr >= s->size) {
> + DPRINTF("Sector request failed:\n");
> + DPRINTF("%s request, idx [%d,%d] size [%llu], "
> + "sector [%llu,%llu]\n",
> + (req->operation == BLKIF_OP_WRITE ?
> + "WRITE" : "READ"),
> + idx,i,
> + (long long unsigned)
> + nsects<<SECTOR_SHIFT,
> + (long long unsigned)
> + sector_nr<<SECTOR_SHIFT,
> + (long long unsigned) sector_nr);
> + continue;
> + }
> +
> + blkif->pending_list[idx].secs_pending += nsects;
> +
> + switch (req->operation)
> + {
> + case BLKIF_OP_WRITE:
> + aiocb_info = malloc(sizeof(*aiocb_info));
> +
> + aiocb_info->s = s;
> + aiocb_info->sector = sector_nr;
> + aiocb_info->nr_secs = nsects;
> + aiocb_info->idx = idx;
> + aiocb_info->i = i;
> +
> + ret = (NULL == bdrv_aio_write(s->bs, sector_nr,
> + page, nsects,
> + qemu_send_responses,
> + aiocb_info));
Who de-allocates aiocb_info?
> +
> + if (ret) {
> + blkif->pending_list[idx].status =
> BLKIF_RSP_ERROR;
> + DPRINTF("ERROR: bdrv_write() ==
> NULL\n");
> + goto send_response;
> + }
> + break;
> +
> + case BLKIF_OP_READ:
> + aiocb_info = malloc(sizeof(*aiocb_info));
> +
> + aiocb_info->s = s;
> + aiocb_info->sector = sector_nr;
> + aiocb_info->nr_secs = nsects;
> + aiocb_info->idx = idx;
> + aiocb_info->i = i;
> +
> + ret = (NULL == bdrv_aio_read(s->bs, sector_nr,
> + page, nsects,
> + qemu_send_responses,
> + aiocb_info));
Ditto.
> +
> + if (ret) {
> + blkif->pending_list[idx].status =
> BLKIF_RSP_ERROR;
> + DPRINTF("ERROR: bdrv_read() == NULL\n");
> + goto send_response;
> + }
> + break;
> +
> + default:
> + DPRINTF("Unknown block operation\n");
> + break;
> + }
> + sector_nr += nsects;
> + }
> + send_response:
> + blkif->pending_list[idx].submitting = 0;
> +
> + /* force write_rsp_to_ring for synchronous case */
> + if (blkif->pending_list[idx].secs_pending == 0)
> + send_responses(s, 0, 0, 0, idx, (void *)(long)0);
> + }
> +}
> +
> +/**
> + * Callback function for the qemu-read pipe. Reads and processes control
> + * message from the pipe.
> + *
> + * The parameter private is unused.
> + */
> +static void handle_blktap_ctrlmsg(void* private)
> +{
> + int length, len, msglen;
> + char *ptr, *path;
> + image_t *img;
> + msg_hdr_t *msg;
> + msg_newdev_t *msg_dev;
> + msg_pid_t *msg_pid;
> + int ret = -1;
> + struct td_state *s = NULL;
> + fd_list_entry_t *entry;
> +
> + char buf[MSG_SIZE];
> +
> + length = read(read_fd, buf, MSG_SIZE);
> +
> + if (length > 0 && length >= sizeof(msg_hdr_t))
> + {
> + msg = (msg_hdr_t *)buf;
> + DPRINTF("blktap: Received msg, len %d, type %d, UID %d\n",
> + length,msg->type,msg->cookie);
> +
> + switch (msg->type) {
> + case CTLMSG_PARAMS:
> + ptr = buf + sizeof(msg_hdr_t);
> + len = (length - sizeof(msg_hdr_t));
> + path = calloc(1, len + 1);
> +
> + memcpy(path, ptr, len);
> + DPRINTF("Received CTLMSG_PARAMS: [%s]\n", path);
> +
> + /* Allocate the disk structs */
> + s = state_init();
> +
> + /*Open file*/
> + if (s == NULL || open_disk(s, path, msg->readonly)) {
> + msglen = sizeof(msg_hdr_t);
> + msg->type = CTLMSG_IMG_FAIL;
> + msg->len = msglen;
> + } else {
> + entry = add_fd_entry(0, s);
> + entry->cookie = msg->cookie;
> + DPRINTF("Entered cookie %d\n", entry->cookie);
> +
> + memset(buf, 0x00, MSG_SIZE);
> +
> + msglen = sizeof(msg_hdr_t) + sizeof(image_t);
> + msg->type = CTLMSG_IMG;
> + img = (image_t *)(buf + sizeof(msg_hdr_t));
> + img->size = s->size;
> + img->secsize = s->sector_size;
> + img->info = s->info;
> + DPRINTF("Writing (size, secsize, info) = "
> + "(%#" PRIx64 ", %#" PRIx64 ", %d)\n",
> + s->size, s->sector_size, s->info);
> + }
> + len = write(write_fd, buf, msglen);
> + free(path);
> + break;
> +
> + case CTLMSG_NEWDEV:
> + msg_dev = (msg_newdev_t *)(buf + sizeof(msg_hdr_t));
> +
> + s = get_state(msg->cookie);
> + DPRINTF("Retrieving state, cookie %d.....[%s]\n",
> + msg->cookie, (s == NULL ? "FAIL":"OK"));
> + if (s != NULL) {
> + ret = ((map_new_dev(s, msg_dev->devnum)
> + == msg_dev->devnum ? 0: -1));
> + }
> +
> + memset(buf, 0x00, MSG_SIZE);
> + msglen = sizeof(msg_hdr_t);
> + msg->type = (ret == 0 ? CTLMSG_NEWDEV_RSP
> + : CTLMSG_NEWDEV_FAIL);
> + msg->len = msglen;
> +
> + len = write(write_fd, buf, msglen);
> + break;
> +
> + case CTLMSG_CLOSE:
> + s = get_state(msg->cookie);
> + if (s) unmap_disk(s);
> + break;
> +
> + case CTLMSG_PID:
> + memset(buf, 0x00, MSG_SIZE);
> + msglen = sizeof(msg_hdr_t) + sizeof(msg_pid_t);
> + msg->type = CTLMSG_PID_RSP;
> + msg->len = msglen;
> +
> + msg_pid = (msg_pid_t *)(buf + sizeof(msg_hdr_t));
> + process = getpid();
> + msg_pid->pid = process;
> +
> + len = write(write_fd, buf, msglen);
> + break;
> +
> + default:
> + break;
> + }
> + }
> +}
> +
> +/**
> + * Opens a control socket, i.e. a pipe to communicate with blktapctrl.
> + *
> + * Returns the file descriptor number for the pipe; -1 in error case
> + */
> +static int open_ctrl_socket(char *devname)
> +{
> + int ret;
> + int ipc_fd;
> +
> + if (mkdir(BLKTAP_CTRL_DIR, 0755) == 0)
> + DPRINTF("Created %s directory\n", BLKTAP_CTRL_DIR);
> +
> + ret = mkfifo(devname,S_IRWXU|S_IRWXG|S_IRWXO);
> + if ( (ret != 0) && (errno != EEXIST) ) {
> + DPRINTF("ERROR: pipe failed (%d)\n", errno);
> + return -1;
> + }
> +
> + ipc_fd = open(devname,O_RDWR|O_NONBLOCK);
> +
> + if (ipc_fd < 0) {
> + DPRINTF("FD open failed\n");
> + return -1;
> + }
> +
> + return ipc_fd;
> +}
> +
> +/**
> + * Unmaps all disks and closes their pipes
> + */
> +void shutdown_blktap(void)
> +{
> + fd_list_entry_t *ptr;
> + struct td_state *s;
> + char *devname;
> +
> + DPRINTF("Shutdown blktap\n");
> +
> + /* Unmap all disks */
> + ptr = fd_start;
> + while (ptr != NULL) {
> + s = ptr->s;
> + unmap_disk(s);
> + close(ptr->tap_fd);
> + ptr = ptr->next;
> + }
> +
> + /* Delete control pipes */
> + if (asprintf(&devname, BLKTAP_CTRL_DIR "/qemu-read-%d", domid) >= 0) {
> + DPRINTF("Delete %s\n", devname);
> + if (unlink(devname))
> + DPRINTF("Could not delete: %s\n", strerror(errno));
> + free(devname);
> + }
> +
> + if (asprintf(&devname, BLKTAP_CTRL_DIR "/qemu-write-%d", domid) >= 0) {
> + DPRINTF("Delete %s\n", devname);
> + if (unlink(devname))
> + DPRINTF("Could not delete: %s\n", strerror(errno));
> + free(devname);
> + }
> +}
> +
> +/**
> + * Initialize the blktap interface, i.e. open a pair of pipes in /var/run/tap
> + * and register a fd handler.
> + *
> + * Returns 0 on success.
> + */
> +int init_blktap(void)
> +{
> + char* devname;
> +
> + DPRINTF("Init blktap pipes\n");
> +
> + /* Open the read pipe */
> + if (asprintf(&devname, BLKTAP_CTRL_DIR "/qemu-read-%d", domid) >= 0) {
> + read_fd = open_ctrl_socket(devname);
> + free(devname);
> +
> + if (read_fd == -1) {
> + fprintf(stderr, "Could not open %s/qemu-read-%d\n",
> + BLKTAP_CTRL_DIR, domid);
> + return -1;
> + }
> + }
> +
> + /* Open the write pipe */
> + if (asprintf(&devname, BLKTAP_CTRL_DIR "/qemu-write-%d", domid) >= 0) {
> + write_fd = open_ctrl_socket(devname);
> + free(devname);
> +
> + if (write_fd == -1) {
> + fprintf(stderr, "Could not open %s/qemu-write-%d\n",
> + BLKTAP_CTRL_DIR, domid);
> + close(read_fd);
> + return -1;
> + }
> + }
> +
> + /* Attach a handler to the read pipe (called from qemu main loop) */
> + qemu_set_fd_handler2(read_fd, NULL, &handle_blktap_ctrlmsg, NULL, NULL);
> +
> + /* Register handler to clean up when the domain is destroyed */
> + atexit(&shutdown_blktap);
> +
> + return 0;
> +}
> diff -r f33328217eee tools/ioemu/hw/xen_blktap.h
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/tools/ioemu/hw/xen_blktap.h Thu Mar 13 13:00:18 2008 +0100
> @@ -0,0 +1,57 @@
> +/* xen_blktap.h
> + *
> + * Generic disk interface for blktap-based image adapters.
> + *
> + * (c) 2006 Andrew Warfield and Julian Chesterfield
> + */
> +
> +#ifndef XEN_BLKTAP_H_
> +#define XEN_BLKTAP_H_
> +
> +#include <stdint.h>
> +#include <syslog.h>
> +#include <stdio.h>
> +
> +#include "block_int.h"
> +
> +/* Things disks need to know about, these should probably be in a
> higher-level
> + * header. */
> +#define MAX_SEGMENTS_PER_REQ 11
> +#define SECTOR_SHIFT 9
> +#define DEFAULT_SECTOR_SIZE 512
> +
> +#define MAX_IOFD 2
> +
> +#define BLK_NOT_ALLOCATED 99
> +#define TD_NO_PARENT 1
> +
> +typedef uint32_t td_flag_t;
> +
> +#define TD_RDONLY 1
> +
> +struct disk_id {
> + char *name;
> + int drivertype;
> +};
> +
> +/* This structure represents the state of an active virtual disk.
> */
> +struct td_state {
> + BlockDriverState* bs;
> + td_flag_t flags;
> + void *blkif;
> + void *image;
> + void *ring_info;
> + void *fd_entry;
> + uint64_t sector_size;
> + uint64_t size;
> + unsigned int info;
> +};
> +
> +typedef struct fd_list_entry {
> + int cookie;
> + int tap_fd;
> + struct td_state *s;
> + struct fd_list_entry **pprev, *next;
> +} fd_list_entry_t;
> +
> +#endif /*XEN_BLKTAP_H_*/
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
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