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path: root/tools/blktap/drivers/blktapctrl.c
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Diffstat (limited to 'tools/blktap/drivers/blktapctrl.c')
-rw-r--r--tools/blktap/drivers/blktapctrl.c201
1 files changed, 101 insertions, 100 deletions
diff --git a/tools/blktap/drivers/blktapctrl.c b/tools/blktap/drivers/blktapctrl.c
index 3e535b9fec..cb2258af42 100644
--- a/tools/blktap/drivers/blktapctrl.c
+++ b/tools/blktap/drivers/blktapctrl.c
@@ -67,16 +67,13 @@ int run = 1;
int max_timeout = MAX_TIMEOUT;
int ctlfd = 0;
+int blktap_major;
+
static int open_ctrl_socket(char *devname);
static int write_msg(int fd, int msgtype, void *ptr, void *ptr2);
static int read_msg(int fd, int msgtype, void *ptr);
static driver_list_entry_t *active_disks[MAX_DISK_TYPES];
-void sig_handler(int sig)
-{
- run = 0;
-}
-
static void init_driver_list(void)
{
int i;
@@ -108,7 +105,18 @@ static void make_blktap_dev(char *devname, int major, int minor)
if (mknod(devname, S_IFCHR|0600,
makedev(major, minor)) == 0)
DPRINTF("Created %s device\n",devname);
- } else DPRINTF("%s device already exists\n",devname);
+ } else {
+ DPRINTF("%s device already exists\n",devname);
+ /* it already exists, but is it the same major number */
+ if (((st.st_rdev>>8) & 0xff) != major) {
+ DPRINTF("%s has old major %d\n",
+ devname,
+ (unsigned int)((st.st_rdev >> 8) & 0xff));
+ /* only try again if we succed in deleting it */
+ if (!unlink(devname))
+ make_blktap_dev(devname, major, minor);
+ }
+ }
}
static int get_new_dev(int *major, int *minor, blkif_t *blkif)
@@ -159,13 +167,22 @@ static int get_tapdisk_pid(blkif_t *blkif)
return 1;
}
-static blkif_t *test_path(char *path, char **dev, int *type)
+/* Look up the disk specified by path:
+ * if found, dev points to the device string in the path
+ * type is the tapdisk driver type id
+ * blkif is the existing interface if this is a shared driver
+ * and NULL otherwise.
+ * return 0 on success, -1 on error.
+ */
+
+static int test_path(char *path, char **dev, int *type, blkif_t *blkif)
{
char *ptr, handle[10];
- int i, size;
+ int i, size, found = 0;
size = sizeof(dtypes)/sizeof(disk_info_t *);
*type = MAX_DISK_TYPES + 1;
+ blkif = NULL;
if ( (ptr = strstr(path, ":"))!=NULL) {
memcpy(handle, path, (ptr - path));
@@ -174,103 +191,81 @@ static blkif_t *test_path(char *path, char **dev, int *type)
*ptr = '\0';
DPRINTF("Detected handle: [%s]\n",handle);
- for (i = 0; i < size; i++) {
- if (strncmp(handle, dtypes[i]->handle, (ptr - path))
- ==0) {
- *type = dtypes[i]->idnum;
-
- if (dtypes[i]->single_handler == 1) {
- /* Check whether tapdisk process
- already exists */
- if (active_disks[dtypes[i]->idnum]
- == NULL) return NULL;
- else
- return active_disks[dtypes[i]->idnum]->blkif;
- }
- }
- }
- } else *dev = NULL;
-
- return NULL;
+ for (i = 0; i < size; i++)
+ if (strncmp(handle, dtypes[i]->handle,
+ (ptr - path)) ==0) {
+ found = 1;
+ break;
+ }
+
+ if (found) {
+ *type = dtypes[i]->idnum;
+
+ if (dtypes[i]->single_handler == 1) {
+ /* Check whether tapdisk process
+ already exists */
+ if (active_disks[dtypes[i]->idnum] == NULL)
+ blkif = NULL;
+ else
+ blkif = active_disks[dtypes[i]
+ ->idnum]->blkif;
+ }
+ return 0;
+ }
+ }
+
+ /* Fall-through case, we didn't find a disk driver. */
+ DPRINTF("Unknown blktap disk type [%s]!\n",handle);
+ *dev = NULL;
+ return -1;
}
+
static void add_disktype(blkif_t *blkif, int type)
{
- driver_list_entry_t *entry, *ptr, *last;
+ driver_list_entry_t *entry, **pprev;
- if (type > MAX_DISK_TYPES) return;
+ if (type > MAX_DISK_TYPES)
+ return;
entry = malloc(sizeof(driver_list_entry_t));
entry->blkif = blkif;
- entry->next = NULL;
- ptr = active_disks[type];
+ entry->next = NULL;
- if (ptr == NULL) {
- active_disks[type] = entry;
- entry->prev = NULL;
- return;
- }
-
- while (ptr != NULL) {
- last = ptr;
- ptr = ptr->next;
- }
+ pprev = &active_disks[type];
+ while (*pprev != NULL)
+ pprev = &(*pprev)->next;
- /*We've found the end of the list*/
- last->next = entry;
- entry->prev = last;
-
- return;
+ *pprev = entry;
+ entry->pprev = pprev;
}
static int del_disktype(blkif_t *blkif)
{
- driver_list_entry_t *ptr, *cur, *last;
+ driver_list_entry_t *entry, **pprev;
int type = blkif->drivertype, count = 0, close = 0;
- if (type > MAX_DISK_TYPES) return 1;
-
- ptr = active_disks[type];
- last = NULL;
- while (ptr != NULL) {
- count++;
- if (blkif == ptr->blkif) {
- cur = ptr;
- if (ptr->next != NULL) {
- /*There's more later in the chain*/
- if (!last) {
- /*We're first in the list*/
- active_disks[type] = ptr->next;
- ptr = ptr->next;
- ptr->prev = NULL;
- }
- else {
- /*We're sandwiched*/
- last->next = ptr->next;
- ptr = ptr->next;
- ptr->prev = last;
- }
-
- } else if (last) {
- /*There's more earlier in the chain*/
- last->next = NULL;
- } else {
- /*We're the only entry*/
- active_disks[type] = NULL;
- if(dtypes[type]->single_handler == 1)
- close = 1;
- }
- DPRINTF("DEL_DISKTYPE: Freeing entry\n");
- free(cur);
- if (dtypes[type]->single_handler == 0) close = 1;
+ if (type > MAX_DISK_TYPES)
+ return 1;
- return close;
- }
- last = ptr;
- ptr = ptr->next;
+ pprev = &active_disks[type];
+ while ((*pprev != NULL) && ((*pprev)->blkif != blkif))
+ pprev = &(*pprev)->next;
+
+ if ((entry = *pprev) == NULL) {
+ DPRINTF("DEL_DISKTYPE: No match\n");
+ return 1;
}
- DPRINTF("DEL_DISKTYPE: No match\n");
- return 1;
+
+ *pprev = entry->next;
+ if (entry->next)
+ entry->next->pprev = pprev;
+
+ DPRINTF("DEL_DISKTYPE: Freeing entry\n");
+ free(entry);
+
+ /* Caller should close() if no single controller, or list is empty. */
+ return (!dtypes[type]->single_handler || (active_disks[type] == NULL));
}
static int write_msg(int fd, int msgtype, void *ptr, void *ptr2)
@@ -425,7 +420,7 @@ static int read_msg(int fd, int msgtype, void *ptr)
image->secsize = img->secsize;
image->info = img->info;
- DPRINTF("Received CTLMSG_IMG: %lu, %lu, %lu\n",
+ DPRINTF("Received CTLMSG_IMG: %llu, %lu, %u\n",
image->size, image->secsize, image->info);
if(msgtype != CTLMSG_IMG) ret = 0;
break;
@@ -487,7 +482,11 @@ int blktapctrl_new_blkif(blkif_t *blkif)
if (get_new_dev(&major, &minor, blkif)<0)
return -1;
- exist = test_path(blk->params, &ptr, &type);
+ if (test_path(blk->params, &ptr, &type, exist) != 0) {
+ DPRINTF("Error in blktap device string(%s).\n",
+ blk->params);
+ return -1;
+ }
blkif->drivertype = type;
blkif->cookie = lrand48() % MAX_RAND_VAL;
@@ -584,8 +583,8 @@ int unmap_blktapctrl(blkif_t *blkif)
if (del_disktype(blkif)) {
close(blkif->fds[WRITE]);
close(blkif->fds[READ]);
-
}
+
return 0;
}
@@ -631,9 +630,11 @@ int main(int argc, char *argv[])
struct xs_handle *h;
struct pollfd pfd[NUM_POLL_FDS];
pid_t process;
+ char buf[128];
__init_blkif();
- openlog("BLKTAPCTRL", LOG_CONS|LOG_ODELAY, LOG_DAEMON);
+ snprintf(buf, sizeof(buf), "BLKTAPCTRL[%d]", getpid());
+ openlog(buf, LOG_CONS|LOG_ODELAY, LOG_DAEMON);
daemon(0,0);
print_drivers();
@@ -644,15 +645,19 @@ int main(int argc, char *argv[])
register_new_devmap_hook(map_new_blktapctrl);
register_new_unmap_hook(unmap_blktapctrl);
- /*Attach to blktap0 */
+ /* Attach to blktap0 */
asprintf(&devname,"%s/%s0", BLKTAP_DEV_DIR, BLKTAP_DEV_NAME);
- make_blktap_dev(devname,254,0);
+ if ((ret = xc_find_device_number("blktap0")) < 0)
+ goto open_failed;
+ blktap_major = major(ret);
+ make_blktap_dev(devname,blktap_major,0);
ctlfd = open(devname, O_RDWR);
if (ctlfd == -1) {
DPRINTF("blktap0 open failed\n");
goto open_failed;
}
+
retry:
/* Set up store connection and watch. */
h = xs_daemon_open();
@@ -666,15 +671,11 @@ int main(int argc, char *argv[])
} else goto open_failed;
}
- ret = add_blockdevice_probe_watch(h, "Domain-0");
+ ret = setup_probe_watch(h);
if (ret != 0) {
DPRINTF("Failed adding device probewatch\n");
- if (count < MAX_ATTEMPTS) {
- count++;
- sleep(2);
- xs_daemon_close(h);
- goto retry;
- } else goto open_failed;
+ xs_daemon_close(h);
+ goto open_failed;
}
ioctl(ctlfd, BLKTAP_IOCTL_SETMODE, BLKTAP_MODE_INTERPOSE );
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-23 10:02:15 +0000