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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v13 03/11] libxl: convert libxl__device_disk_local_attach to an async op
This will be needed in future patches, when libxl__device_disk_add
becomes async also. Create a new status structure that defines the
local attach of a disk device and use it in
libxl__device_disk_local_attach.
This is done in this patch to split the changes introduced when
libxl__device_disk_add becomes async.
Changes since v11:
* Correctly pass error in libxl__device_disk_local_initiate_detach.
Changes since v10:
* Convert breaks to gotos in error paths of
libxl__device_disk_local_initiate_attach.
* Unify exit path of libxl__device_disk_local_detach.
* Redo some comments.
Changes since v9:
* Fixed state changes comments on header of functions.
* Rework libxl__device_disk_local_init to just set rc to 0, and
perform the initialization in the callers context.
* If attach fails, perform a detach, so the state of the local_device
on the callback is Attached if rc == 0, or Idle if rc != 0.
* Free diskpath inside the detach callback.
Changes since v6:
* Added better comments.
* Instead of passing the xs_transaction arround several functions,
put all the xs related operations inside device_disk_add.
* Make sure libxl__device_disk_local_initiate_detach either calls the
async device destroy function, or the callback.
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Signed-off-by: Roger Pau Monne <roger.pau@xxxxxxxxxx>
---
tools/libxl/libxl.c | 98 ++++++++++++++++++++++++++++++---------
tools/libxl/libxl_bootloader.c | 73 ++++++++++++++++++++++++------
tools/libxl/libxl_internal.h | 72 +++++++++++++++++++++++------
3 files changed, 192 insertions(+), 51 deletions(-)
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 5565a7b..f7fca95 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2191,19 +2191,19 @@ static char * libxl__alloc_vdev(libxl__gc *gc, void
*get_vdev_user,
return NULL;
}
-char * libxl__device_disk_local_attach(libxl__gc *gc,
- const libxl_device_disk *in_disk,
- libxl_device_disk *disk,
- const char *blkdev_start)
+void libxl__device_disk_local_initiate_attach(libxl__egc *egc,
+ libxl__disk_local_state *dls)
{
- libxl_ctx *ctx = gc->owner;
+ STATE_AO_GC(dls->ao);
+ libxl_ctx *ctx = CTX;
char *dev = NULL, *be_path = NULL;
- char *ret = NULL;
int rc;
libxl__device device;
+ const libxl_device_disk *in_disk = dls->in_disk;
+ libxl_device_disk *disk = &dls->disk;
+ const char *blkdev_start = dls->blkdev_start;
- if (in_disk->pdev_path == NULL)
- return NULL;
+ assert(in_disk->pdev_path);
memcpy(disk, in_disk, sizeof(libxl_device_disk));
disk->pdev_path = libxl__strdup(gc, in_disk->pdev_path);
@@ -2239,7 +2239,8 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
default:
LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
"unrecognized disk format: %d", disk->format);
- break;
+ rc = ERROR_FAIL;
+ goto out;
}
break;
case LIBXL_DISK_BACKEND_QDISK:
@@ -2248,6 +2249,7 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
libxl__alloc_vdev,
(void *) blkdev_start)) {
LOG(ERROR, "libxl_device_disk_add failed");
+ rc = ERROR_FAIL;
goto out;
}
dev = GCSPRINTF("/dev/%s", disk->vdev);
@@ -2259,7 +2261,8 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
default:
LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "unrecognized disk backend "
"type: %d", disk->backend);
- break;
+ rc = ERROR_FAIL;
+ goto out;
}
if (disk->vdev != NULL) {
@@ -2272,39 +2275,88 @@ char * libxl__device_disk_local_attach(libxl__gc *gc,
goto out;
}
if (dev != NULL)
- ret = strdup(dev);
- return ret;
+ dls->diskpath = libxl__strdup(gc, dev);
+
+ dls->callback(egc, dls, 0);
+ return;
out:
- libxl__device_disk_local_detach(gc, disk);
- return NULL;
+ assert(rc);
+ dls->rc = rc;
+ libxl__device_disk_local_initiate_detach(egc, dls);
+ return;
}
-int libxl__device_disk_local_detach(libxl__gc *gc, libxl_device_disk *disk)
+/* Callbacks for local detach */
+
+static void local_device_detach_cb(libxl__egc *egc, libxl__ao_device *aodev);
+
+void libxl__device_disk_local_initiate_detach(libxl__egc *egc,
+ libxl__disk_local_state *dls)
{
+ STATE_AO_GC(dls->ao);
int rc = 0;
+ libxl_device_disk *disk = &dls->disk;
+ libxl__device *device;
+ libxl__ao_device *aodev = &dls->aodev;
+ libxl__prepare_ao_device(ao, aodev);
+
+ if (!dls->diskpath) goto out;
switch (disk->backend) {
case LIBXL_DISK_BACKEND_QDISK:
if (disk->vdev != NULL) {
- libxl_device_disk_remove(gc->owner, LIBXL_TOOLSTACK_DOMID,
- disk, 0);
- /* fixme-ao */
- rc = libxl_device_disk_destroy(gc->owner,
- LIBXL_TOOLSTACK_DOMID, disk, 0);
+ GCNEW(device);
+ rc = libxl__device_from_disk(gc, LIBXL_TOOLSTACK_DOMID,
+ disk, device);
+ if (rc != 0) goto out;
+
+ aodev->action = DEVICE_DISCONNECT;
+ aodev->dev = device;
+ aodev->callback = local_device_detach_cb;
+ aodev->force = 0;
+ libxl__initiate_device_remove(egc, aodev);
+ return;
}
- break;
+ /* disk->vdev == NULL; fall through */
default:
/*
* Nothing to do for PHYSTYPE_PHY.
* For other device types assume that the blktap2 process is
* needed by the soon to be started domain and do nothing.
*/
- break;
+ goto out;
}
+out:
+ aodev->rc = rc;
+ local_device_detach_cb(egc, aodev);
+ return;
+}
- return rc;
+static void local_device_detach_cb(libxl__egc *egc, libxl__ao_device *aodev)
+{
+ STATE_AO_GC(aodev->ao);
+ libxl__disk_local_state *dls = CONTAINER_OF(aodev, *dls, aodev);
+ int rc;
+
+ if (aodev->rc) {
+ LOGE(ERROR, "unable to %s %s with id %u",
+ aodev->action == DEVICE_CONNECT ? "add" : "remove",
+ libxl__device_kind_to_string(aodev->dev->kind),
+ aodev->dev->devid);
+ goto out;
+ }
+
+out:
+ /*
+ * If there was an error in dls->rc, it means we have been called from
+ * a failed execution of libxl__device_disk_local_initiate_attach,
+ * so return the original error.
+ */
+ rc = dls->rc ? dls->rc : aodev->rc;
+ dls->callback(egc, dls, rc);
+ return;
}
/******************************************************************************/
diff --git a/tools/libxl/libxl_bootloader.c b/tools/libxl/libxl_bootloader.c
index 7ebc0df..ef5a91b 100644
--- a/tools/libxl/libxl_bootloader.c
+++ b/tools/libxl/libxl_bootloader.c
@@ -75,7 +75,7 @@ static void make_bootloader_args(libxl__gc *gc,
libxl__bootloader_state *bl,
}
}
- ARG(bl->diskpath);
+ ARG(bl->dls.diskpath);
/* Sentinel for execv */
ARG(NULL);
@@ -206,8 +206,9 @@ static int parse_bootloader_result(libxl__egc *egc,
void libxl__bootloader_init(libxl__bootloader_state *bl)
{
assert(bl->ao);
- bl->diskpath = NULL;
+ bl->dls.diskpath = NULL;
bl->openpty.ao = bl->ao;
+ bl->dls.ao = bl->ao;
bl->ptys[0].master = bl->ptys[0].slave = 0;
bl->ptys[1].master = bl->ptys[1].slave = 0;
libxl__ev_child_init(&bl->child);
@@ -224,11 +225,6 @@ static void bootloader_cleanup(libxl__egc *egc,
libxl__bootloader_state *bl)
if (bl->outputpath) libxl__remove_file(gc, bl->outputpath);
if (bl->outputdir) libxl__remove_directory(gc, bl->outputdir);
- if (bl->diskpath) {
- libxl__device_disk_local_detach(gc, &bl->localdisk);
- free(bl->diskpath);
- bl->diskpath = 0;
- }
libxl__domaindeathcheck_stop(gc,&bl->deathcheck);
libxl__datacopier_kill(&bl->keystrokes);
libxl__datacopier_kill(&bl->display);
@@ -249,10 +245,32 @@ static void bootloader_setpaths(libxl__gc *gc,
libxl__bootloader_state *bl)
bl->outputpath = GCSPRINTF(XEN_RUN_DIR "/bootloader.%"PRIu32".out", domid);
}
+/* Callbacks */
+
+static void bootloader_local_detached_cb(libxl__egc *egc,
+ libxl__disk_local_state *dls,
+ int rc);
+
static void bootloader_callback(libxl__egc *egc, libxl__bootloader_state *bl,
int rc)
{
bootloader_cleanup(egc, bl);
+
+ bl->dls.callback = bootloader_local_detached_cb;
+ libxl__device_disk_local_initiate_detach(egc, &bl->dls);
+}
+
+static void bootloader_local_detached_cb(libxl__egc *egc,
+ libxl__disk_local_state *dls,
+ int rc)
+{
+ STATE_AO_GC(dls->ao);
+ libxl__bootloader_state *bl = CONTAINER_OF(dls, *bl, dls);
+
+ if (rc) {
+ LOG(ERROR, "unable to detach locally attached disk");
+ }
+
bl->callback(egc, bl, rc);
}
@@ -275,6 +293,12 @@ static void bootloader_abort(libxl__egc *egc,
/*----- main flow of control -----*/
+/* Callbacks */
+
+static void bootloader_disk_attached_cb(libxl__egc *egc,
+ libxl__disk_local_state *dls,
+ int rc);
+
void libxl__bootloader_run(libxl__egc *egc, libxl__bootloader_state *bl)
{
STATE_AO_GC(bl->ao);
@@ -282,7 +306,6 @@ void libxl__bootloader_run(libxl__egc *egc,
libxl__bootloader_state *bl)
uint32_t domid = bl->domid;
char *logfile_tmp = NULL;
int rc, r;
- const char *bootloader;
libxl__bootloader_init(bl);
@@ -344,10 +367,34 @@ void libxl__bootloader_run(libxl__egc *egc,
libxl__bootloader_state *bl)
goto out;
}
- bl->diskpath = libxl__device_disk_local_attach(gc, bl->disk,
&bl->localdisk,
- info->blkdev_start);
- if (!bl->diskpath) {
- rc = ERROR_FAIL;
+
+ /* This sets the state of the dls struct from Undefined to Idle */
+ libxl__device_disk_local_init(&bl->dls);
+ bl->dls.ao = ao;
+ bl->dls.in_disk = bl->disk;
+ bl->dls.blkdev_start = info->blkdev_start;
+ bl->dls.callback = bootloader_disk_attached_cb;
+ libxl__device_disk_local_initiate_attach(egc, &bl->dls);
+ return;
+
+ out:
+ assert(rc);
+ out_ok:
+ free(logfile_tmp);
+ bootloader_callback(egc, bl, rc);
+}
+
+static void bootloader_disk_attached_cb(libxl__egc *egc,
+ libxl__disk_local_state *dls,
+ int rc)
+{
+ STATE_AO_GC(dls->ao);
+ libxl__bootloader_state *bl = CONTAINER_OF(dls, *bl, dls);
+ const libxl_domain_build_info *info = bl->info;
+ const char *bootloader;
+
+ if (rc) {
+ LOG(ERROR, "failed to attach local disk for bootloader execution");
goto out;
}
@@ -389,8 +436,6 @@ void libxl__bootloader_run(libxl__egc *egc,
libxl__bootloader_state *bl)
out:
assert(rc);
- out_ok:
- free(logfile_tmp);
bootloader_callback(egc, bl, rc);
}
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 2cc3f86..2bef0af 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1336,17 +1336,6 @@ _hidden int libxl__device_from_disk(libxl__gc *gc,
uint32_t domid,
_hidden int libxl__device_disk_add(libxl__gc *gc, uint32_t domid,
libxl_device_disk *disk);
-/*
- * Make a disk available in this (the control) domain. Returns path to
- * a device.
- */
-_hidden char * libxl__device_disk_local_attach(libxl__gc *gc,
- const libxl_device_disk *in_disk,
- libxl_device_disk *new_disk,
- const char *blkdev_start);
-_hidden int libxl__device_disk_local_detach(libxl__gc *gc,
- libxl_device_disk *disk);
-
_hidden char *libxl__uuid2string(libxl__gc *gc, const libxl_uuid uuid);
struct libxl__xen_console_reader {
@@ -1943,6 +1932,62 @@ struct libxl__ao_devices {
_hidden void libxl__initiate_device_remove(libxl__egc *egc,
libxl__ao_device *aodev);
+/*----- local disk attach: attach a disk locally to run the bootloader -----*/
+
+typedef struct libxl__disk_local_state libxl__disk_local_state;
+typedef void libxl__disk_local_state_callback(libxl__egc*,
+ libxl__disk_local_state*,
+ int rc);
+
+/* A libxl__disk_local_state may be in the following states:
+ * Undefined, Idle, Attaching, Attached, Detaching.
+ */
+struct libxl__disk_local_state {
+ /* filled by the user */
+ libxl__ao *ao;
+ const libxl_device_disk *in_disk;
+ libxl_device_disk disk;
+ const char *blkdev_start;
+ libxl__disk_local_state_callback *callback;
+ /* filled by libxl__device_disk_local_initiate_attach */
+ char *diskpath;
+ /* private for implementation of local detach */
+ libxl__ao_device aodev;
+ int rc;
+};
+
+/*
+ * Prepares a dls for use.
+ * State Undefined -> Idle
+ */
+static inline void libxl__device_disk_local_init(libxl__disk_local_state *dls)
+{
+ dls->rc = 0;
+}
+
+/* Make a disk available in this (the control) domain. Always calls
+ * dls->callback when finished.
+ * State Idle -> Attaching
+ *
+ * The state of dls on entry to the callback depends on the value
+ * of rc passed to the callback:
+ * rc == 0: Attached if rc == 0
+ * rc != 0: Idle
+ */
+_hidden void libxl__device_disk_local_initiate_attach(libxl__egc *egc,
+ libxl__disk_local_state *dls);
+
+/* Disconnects a disk device form the control domain. If the passed
+ * dls is not attached (or has already been detached),
+ * libxl__device_disk_local_initiate_detach will just call the callback
+ * directly.
+ * State Idle/Attached -> Detaching
+ *
+ * The state of dls on entry to the callback is Idle.
+ */
+_hidden void libxl__device_disk_local_initiate_detach(libxl__egc *egc,
+ libxl__disk_local_state *dls);
+
/*----- datacopier: copies data from one fd to another -----*/
typedef struct libxl__datacopier_state libxl__datacopier_state;
@@ -2132,12 +2177,12 @@ struct libxl__bootloader_state {
/* Should be zeroed by caller on entry. Will be filled in by
* bootloader machinery; represents the local attachment of the
* disk for the benefit of the bootloader. Must be detached by
- * the caller using libxl__device_disk_local_detach.
+ * the caller using libxl__device_disk_local_initiate_detach.
* (This is safe to do after ->callback() has happened since
* the domain's kernel and initramfs will have been copied
* out of the guest's disk into a temporary directory, mapped
* as file references, and deleted. */
- libxl_device_disk localdisk;
+ libxl__disk_local_state dls;
uint32_t domid;
/* outputs:
* - caller must initialise kernel and ramdisk to point to file
@@ -2149,7 +2194,6 @@ struct libxl__bootloader_state {
const char *cmdline;
/* private to libxl__run_bootloader */
char *outputpath, *outputdir, *logfile;
- char *diskpath; /* not from gc, represents actually attached disk */
libxl__openpty_state openpty;
libxl__openpty_result ptys[2]; /* [0] is for bootloader */
libxl__ev_child child;
--
1.7.7.5 (Apple Git-26)
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