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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v13 02/11] libxl: refactor disk addition to take a helper
Change libxl__device_disk_add to no longer take a xs transaction and
instead pass a helper for the local attach case that's used to get the
free vdev.
This function contains some non-functional changes due to an
indentation change.
Changes since v11:
* Fixed type correctness in helper function passed to device_disk_add
and caller.
Changes since v10:
* Changed name/type of params of device_disk_add.
Changes since v9:
* Added better comment for device_disk_add parameters.
* Changed char *fn to void *get_vdev_user
* Removed error log message.
Changes since v7:
* Fixed the use of the transaction inside device_disk_add (which in
v7 was fixed in the next patch).
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Signed-off-by: Roger Pau Monne <roger.pau@xxxxxxxxxx>
---
tools/libxl/libxl.c | 270 +++++++++++++++++++++++-------------------
tools/libxl/libxl_internal.h | 2 +-
2 files changed, 148 insertions(+), 124 deletions(-)
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 559b45e..5565a7b 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1774,115 +1774,152 @@ int libxl__device_from_disk(libxl__gc *gc, uint32_t
domid,
return 0;
}
-int libxl__device_disk_add(libxl__gc *gc, uint32_t domid,
- xs_transaction_t t, libxl_device_disk *disk)
-{
- flexarray_t *front;
- flexarray_t *back;
+/* Specific function called directly only by local disk attach,
+ * all other users should instead use the regular
+ * libxl__device_disk_add wrapper
+ *
+ * The (optionally) passed function get_vdev will be used to
+ * set the vdev the disk should be attached to. When it is set the caller
+ * must also pass get_vdev_user, which will be passed to get_vdev.
+ *
+ * The passed get_vdev function is also in charge of printing
+ * the corresponding error message when appropiate.
+ */
+static int device_disk_add(libxl__gc *gc, uint32_t domid,
+ libxl_device_disk *disk,
+ char *get_vdev(libxl__gc *, void *,
+ xs_transaction_t),
+ void *get_vdev_user)
+{
+ flexarray_t *front = NULL;
+ flexarray_t *back = NULL;
char *dev;
libxl__device device;
int major, minor, rc;
libxl_ctx *ctx = gc->owner;
+ xs_transaction_t t = XBT_NULL;
- rc = libxl__device_disk_setdefault(gc, disk);
- if (rc) goto out;
+ for (;;) {
+ rc = libxl__xs_transaction_start(gc, &t);
+ if (rc) goto out;
- front = flexarray_make(16, 1);
- if (!front) {
- rc = ERROR_NOMEM;
- goto out;
- }
- back = flexarray_make(16, 1);
- if (!back) {
- rc = ERROR_NOMEM;
- goto out_free;
- }
+ if (get_vdev) {
+ assert(get_vdev_user);
+ disk->vdev = get_vdev(gc, get_vdev_user, t);
+ if (disk->vdev == NULL) {
+ rc = ERROR_FAIL;
+ goto out;
+ }
+ }
- if (disk->script) {
- LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "External block scripts"
- " not yet supported, sorry");
- rc = ERROR_INVAL;
- goto out_free;
- }
+ rc = libxl__device_disk_setdefault(gc, disk);
+ if (rc) goto out;
- rc = libxl__device_from_disk(gc, domid, disk, &device);
- if (rc != 0) {
- LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Invalid or unsupported"
- " virtual disk identifier %s", disk->vdev);
- goto out_free;
- }
+ if (front)
+ flexarray_free(front);
+ front = flexarray_make(16, 1);
+ if (!front) {
+ rc = ERROR_NOMEM;
+ goto out;
+ }
+ if (back)
+ flexarray_free(back);
+ back = flexarray_make(16, 1);
+ if (!back) {
+ rc = ERROR_NOMEM;
+ goto out_free;
+ }
- switch (disk->backend) {
- case LIBXL_DISK_BACKEND_PHY:
- dev = disk->pdev_path;
- do_backend_phy:
- libxl__device_physdisk_major_minor(dev, &major, &minor);
- flexarray_append(back, "physical-device");
- flexarray_append(back, libxl__sprintf(gc, "%x:%x", major, minor));
+ if (disk->script) {
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "External block scripts"
+ " not yet supported, sorry");
+ rc = ERROR_INVAL;
+ goto out_free;
+ }
- flexarray_append(back, "params");
- flexarray_append(back, dev);
+ rc = libxl__device_from_disk(gc, domid, disk, &device);
+ if (rc != 0) {
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Invalid or unsupported"
+ " virtual disk identifier %s", disk->vdev);
+ goto out_free;
+ }
- assert(device.backend_kind == LIBXL__DEVICE_KIND_VBD);
- break;
- case LIBXL_DISK_BACKEND_TAP:
- dev = libxl__blktap_devpath(gc, disk->pdev_path, disk->format);
- if (!dev) {
- LOG(ERROR, "failed to get blktap devpath for %p\n",
- disk->pdev_path);
- rc = ERROR_FAIL;
- goto out_free;
- }
- flexarray_append(back, "tapdisk-params");
- flexarray_append(back, libxl__sprintf(gc, "%s:%s",
- libxl__device_disk_string_of_format(disk->format),
- disk->pdev_path));
+ switch (disk->backend) {
+ case LIBXL_DISK_BACKEND_PHY:
+ dev = disk->pdev_path;
+ do_backend_phy:
+ libxl__device_physdisk_major_minor(dev, &major, &minor);
+ flexarray_append(back, "physical-device");
+ flexarray_append(back, libxl__sprintf(gc, "%x:%x", major,
minor));
- /* now create a phy device to export the device to the guest */
- goto do_backend_phy;
- case LIBXL_DISK_BACKEND_QDISK:
- flexarray_append(back, "params");
- flexarray_append(back, libxl__sprintf(gc, "%s:%s",
- libxl__device_disk_string_of_format(disk->format),
disk->pdev_path));
- assert(device.backend_kind == LIBXL__DEVICE_KIND_QDISK);
- break;
- default:
- LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "unrecognized disk backend type:
%d\n", disk->backend);
- rc = ERROR_INVAL;
- goto out_free;
- }
+ flexarray_append(back, "params");
+ flexarray_append(back, dev);
- flexarray_append(back, "frontend-id");
- flexarray_append(back, libxl__sprintf(gc, "%d", domid));
- flexarray_append(back, "online");
- flexarray_append(back, "1");
- flexarray_append(back, "removable");
- flexarray_append(back, libxl__sprintf(gc, "%d", (disk->removable) ? 1 :
0));
- flexarray_append(back, "bootable");
- flexarray_append(back, libxl__sprintf(gc, "%d", 1));
- flexarray_append(back, "state");
- flexarray_append(back, libxl__sprintf(gc, "%d", 1));
- flexarray_append(back, "dev");
- flexarray_append(back, disk->vdev);
- flexarray_append(back, "type");
- flexarray_append(back,
libxl__device_disk_string_of_backend(disk->backend));
- flexarray_append(back, "mode");
- flexarray_append(back, disk->readwrite ? "w" : "r");
- flexarray_append(back, "device-type");
- flexarray_append(back, disk->is_cdrom ? "cdrom" : "disk");
+ assert(device.backend_kind == LIBXL__DEVICE_KIND_VBD);
+ break;
+ case LIBXL_DISK_BACKEND_TAP:
+ dev = libxl__blktap_devpath(gc, disk->pdev_path, disk->format);
+ if (!dev) {
+ LOG(ERROR, "failed to get blktap devpath for %p\n",
+ disk->pdev_path);
+ rc = ERROR_FAIL;
+ goto out_free;
+ }
+ flexarray_append(back, "tapdisk-params");
+ flexarray_append(back, libxl__sprintf(gc, "%s:%s",
+ libxl__device_disk_string_of_format(disk->format),
+ disk->pdev_path));
+
+ /* now create a phy device to export the device to the guest */
+ goto do_backend_phy;
+ case LIBXL_DISK_BACKEND_QDISK:
+ flexarray_append(back, "params");
+ flexarray_append(back, libxl__sprintf(gc, "%s:%s",
+
libxl__device_disk_string_of_format(disk->format), disk->pdev_path));
+ assert(device.backend_kind == LIBXL__DEVICE_KIND_QDISK);
+ break;
+ default:
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "unrecognized disk backend
type: %d\n", disk->backend);
+ rc = ERROR_INVAL;
+ goto out_free;
+ }
- flexarray_append(front, "backend-id");
- flexarray_append(front, libxl__sprintf(gc, "%d", disk->backend_domid));
- flexarray_append(front, "state");
- flexarray_append(front, libxl__sprintf(gc, "%d", 1));
- flexarray_append(front, "virtual-device");
- flexarray_append(front, libxl__sprintf(gc, "%d", device.devid));
- flexarray_append(front, "device-type");
- flexarray_append(front, disk->is_cdrom ? "cdrom" : "disk");
+ flexarray_append(back, "frontend-id");
+ flexarray_append(back, libxl__sprintf(gc, "%d", domid));
+ flexarray_append(back, "online");
+ flexarray_append(back, "1");
+ flexarray_append(back, "removable");
+ flexarray_append(back, libxl__sprintf(gc, "%d", (disk->removable) ? 1
: 0));
+ flexarray_append(back, "bootable");
+ flexarray_append(back, libxl__sprintf(gc, "%d", 1));
+ flexarray_append(back, "state");
+ flexarray_append(back, libxl__sprintf(gc, "%d", 1));
+ flexarray_append(back, "dev");
+ flexarray_append(back, disk->vdev);
+ flexarray_append(back, "type");
+ flexarray_append(back,
libxl__device_disk_string_of_backend(disk->backend));
+ flexarray_append(back, "mode");
+ flexarray_append(back, disk->readwrite ? "w" : "r");
+ flexarray_append(back, "device-type");
+ flexarray_append(back, disk->is_cdrom ? "cdrom" : "disk");
+
+ flexarray_append(front, "backend-id");
+ flexarray_append(front, libxl__sprintf(gc, "%d", disk->backend_domid));
+ flexarray_append(front, "state");
+ flexarray_append(front, libxl__sprintf(gc, "%d", 1));
+ flexarray_append(front, "virtual-device");
+ flexarray_append(front, libxl__sprintf(gc, "%d", device.devid));
+ flexarray_append(front, "device-type");
+ flexarray_append(front, disk->is_cdrom ? "cdrom" : "disk");
- libxl__device_generic_add(gc, t, &device,
- libxl__xs_kvs_of_flexarray(gc, back, back->count),
- libxl__xs_kvs_of_flexarray(gc, front,
front->count));
+ libxl__device_generic_add(gc, t, &device,
+ libxl__xs_kvs_of_flexarray(gc, back, back->count),
+ libxl__xs_kvs_of_flexarray(gc, front,
front->count));
+
+ rc = libxl__xs_transaction_commit(gc, &t);
+ if (!rc) break;
+ if (rc < 0) goto out_free;
+ }
rc = 0;
@@ -1890,13 +1927,20 @@ out_free:
flexarray_free(back);
flexarray_free(front);
out:
+ libxl__xs_transaction_abort(gc, &t);
return rc;
}
+int libxl__device_disk_add(libxl__gc *gc, uint32_t domid,
+ libxl_device_disk *disk)
+{
+ return device_disk_add(gc, domid, disk, NULL, NULL);
+}
+
int libxl_device_disk_add(libxl_ctx *ctx, uint32_t domid, libxl_device_disk
*disk)
{
GC_INIT(ctx);
- int rc = libxl__device_disk_add(gc, domid, XBT_NULL, disk);
+ int rc = libxl__device_disk_add(gc, domid, disk);
GC_FREE;
return rc;
}
@@ -2116,9 +2160,10 @@ out:
/* libxl__alloc_vdev only works on the local domain, that is the domain
* where the toolstack is running */
-static char * libxl__alloc_vdev(libxl__gc *gc, const char *blkdev_start,
+static char * libxl__alloc_vdev(libxl__gc *gc, void *get_vdev_user,
xs_transaction_t t)
{
+ const char *blkdev_start = (const char *) get_vdev_user;
int devid = 0, disk = 0, part = 0;
char *dompath = libxl__xs_get_dompath(gc, LIBXL_TOOLSTACK_DOMID);
@@ -2154,9 +2199,8 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
libxl_ctx *ctx = gc->owner;
char *dev = NULL, *be_path = NULL;
char *ret = NULL;
- int rc, xs_ret;
+ int rc;
libxl__device device;
- xs_transaction_t t = XBT_NULL;
if (in_disk->pdev_path == NULL)
return NULL;
@@ -2200,27 +2244,10 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
break;
case LIBXL_DISK_BACKEND_QDISK:
if (disk->format != LIBXL_DISK_FORMAT_RAW) {
- do {
- t = xs_transaction_start(ctx->xsh);
- if (t == XBT_NULL) {
- LOG(ERROR, "failed to start a xenstore transaction");
- goto out;
- }
- disk->vdev = libxl__alloc_vdev(gc, blkdev_start, t);
- if (disk->vdev == NULL) {
- LOG(ERROR, "libxl__alloc_vdev failed");
- goto out;
- }
- if (libxl__device_disk_add(gc, LIBXL_TOOLSTACK_DOMID,
- t, disk)) {
- LOG(ERROR, "libxl_device_disk_add failed");
- goto out;
- }
- xs_ret = xs_transaction_end(ctx->xsh, t, 0);
- } while (xs_ret == 0 && errno == EAGAIN);
- t = XBT_NULL;
- if (xs_ret == 0) {
- LOGE(ERROR, "xenstore transaction failed");
+ if (device_disk_add(gc, LIBXL_TOOLSTACK_DOMID, disk,
+ libxl__alloc_vdev,
+ (void *) blkdev_start)) {
+ LOG(ERROR, "libxl_device_disk_add failed");
goto out;
}
dev = GCSPRINTF("/dev/%s", disk->vdev);
@@ -2249,10 +2276,7 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
return ret;
out:
- if (t != XBT_NULL)
- xs_transaction_end(ctx->xsh, t, 1);
- else
- libxl__device_disk_local_detach(gc, disk);
+ libxl__device_disk_local_detach(gc, disk);
return NULL;
}
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 1b9b417..2cc3f86 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1334,7 +1334,7 @@ _hidden int libxl__device_from_disk(libxl__gc *gc,
uint32_t domid,
libxl_device_disk *disk,
libxl__device *device);
_hidden int libxl__device_disk_add(libxl__gc *gc, uint32_t domid,
- xs_transaction_t t, libxl_device_disk *disk);
+ libxl_device_disk *disk);
/*
* Make a disk available in this (the control) domain. Returns path to
--
1.7.7.5 (Apple Git-26)
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