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ocf: implement metadata probe

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Implement metadata probe functionality to load cache state
  from disk.
During metadata probe, we inspect UUIDs of core devices
  and create vbdev configurations based on them.
  Then, to start vbdev, we use load path (loadq = true).

After this change persistent metadata is officially supported,
  we can save and restore cache state from persistant storage.

WriteBack mode is now safe to use in respect to unexpected shutdowns,
  because all information about dirty data is also restored during cache load.

Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/455417 (master)

(cherry picked from commit 9686948334)
Change-Id: I6cf86aabd68177b88638a68ea6a5b78a1068a4d0
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/457584
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
This commit is contained in:
Vitaliy Mysak 2019-05-21 21:02:05 +00:00 committed by Ben Walker
parent a7411e316a
commit 3768d9a8c6
1 changed files with 186 additions and 4 deletions
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190
lib/bdev/ocf/vbdev_ocf.c
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@ -1037,7 +1037,7 @@ init_vbdev_config(struct vbdev_ocf *vbdev)
/* TODO [metadata]: make configurable with persistent
* metadata support */
cfg->cache.metadata_volatile = true;
cfg->cache.metadata_volatile = false;
/* TODO [cache line size]: make cache line size configurable
* Using standard 4KiB for now */
@ -1397,15 +1397,155 @@ vbdev_ocf_examine(struct spdk_bdev *bdev)
spdk_bdev_module_examine_done(&ocf_if);
}
struct metadata_probe_ctx {
struct vbdev_ocf_base base;
ocf_volume_t volume;
struct ocf_volume_uuid *core_uuids;
unsigned int uuid_count;
int result;
int refcnt;
};
static void
examine_ctx_put(struct metadata_probe_ctx *ctx)
{
unsigned int i;
ctx->refcnt--;
if (ctx->refcnt > 0) {
return;
}
if (ctx->result) {
SPDK_ERRLOG("OCF metadata probe for bdev '%s' failed with %d\n",
spdk_bdev_get_name(ctx->base.bdev), ctx->result);
}
if (ctx->base.desc) {
spdk_bdev_close(ctx->base.desc);
}
if (ctx->volume) {
ocf_volume_destroy(ctx->volume);
}
if (ctx->core_uuids) {
for (i = 0; i < ctx->uuid_count; i++) {
free(ctx->core_uuids[i].data);
}
}
free(ctx->core_uuids);
examine_done(ctx->result, NULL, ctx->base.bdev);
free(ctx);
}
static void
metadata_probe_construct_cb(int rc, struct vbdev_ocf *vbdev, void *vctx)
{
struct metadata_probe_ctx *ctx = vctx;
examine_ctx_put(ctx);
}
/* This is second callback for ocf_metadata_probe_cores()
* Here we create vbdev configurations based on UUIDs */
static void
metadata_probe_cores_construct(void *priv, int error, unsigned int num_cores)
{
struct metadata_probe_ctx *ctx = priv;
const char *vbdev_name;
const char *core_name;
unsigned int i;
if (error) {
ctx->result = error;
examine_ctx_put(ctx);
return;
}
for (i = 0; i < num_cores; i++) {
core_name = ocf_uuid_to_str(&ctx->core_uuids[i]);
vbdev_name = core_name + strlen(core_name) + 1;
ctx->refcnt++;
vbdev_ocf_construct(vbdev_name, NULL, ctx->base.bdev->name, core_name, true,
metadata_probe_construct_cb, ctx);
}
examine_ctx_put(ctx);
}
/* This callback is called after OCF reads cores UUIDs from cache metadata
* Here we allocate memory for those UUIDs and call ocf_metadata_probe_cores() again */
static void
metadata_probe_cores_get_num(void *priv, int error, unsigned int num_cores)
{
struct metadata_probe_ctx *ctx = priv;
unsigned int i;
if (error) {
ctx->result = error;
examine_ctx_put(ctx);
return;
}
ctx->uuid_count = num_cores;
ctx->core_uuids = calloc(num_cores, sizeof(struct ocf_volume_uuid));
if (!ctx->core_uuids) {
ctx->result = -ENOMEM;
examine_ctx_put(ctx);
return;
}
for (i = 0; i < ctx->uuid_count; i++) {
ctx->core_uuids[i].size = OCF_VOLUME_UUID_MAX_SIZE;
ctx->core_uuids[i].data = malloc(OCF_VOLUME_UUID_MAX_SIZE);
if (!ctx->core_uuids[i].data) {
ctx->result = -ENOMEM;
examine_ctx_put(ctx);
return;
}
}
ocf_metadata_probe_cores(vbdev_ocf_ctx, ctx->volume, ctx->core_uuids, ctx->uuid_count,
metadata_probe_cores_construct, ctx);
}
static void
metadata_probe_cb(void *priv, int rc,
struct ocf_metadata_probe_status *status)
{
struct metadata_probe_ctx *ctx = priv;
if (rc) {
/* -ENODATA means device does not have cache metadata on it */
if (rc != -ENODATA) {
ctx->result = rc;
}
examine_ctx_put(ctx);
return;
}
ocf_metadata_probe_cores(vbdev_ocf_ctx, ctx->volume, NULL, 0,
metadata_probe_cores_get_num, ctx);
}
/* This is called after vbdev_ocf_examine
* It allows to delay application initialization
* until all OCF bdevs get registered
* If vbdev has all of its base devices it starts asynchronously here */
* If vbdev has all of its base devices it starts asynchronously here
* We first check if bdev appears in configuration,
* if not we do metadata_probe() to create its configuration from bdev metadata */
static void
vbdev_ocf_examine_disk(struct spdk_bdev *bdev)
{
const char *bdev_name = spdk_bdev_get_name(bdev);
struct vbdev_ocf *vbdev;
struct metadata_probe_ctx *ctx;
bool created_from_config = false;
int rc;
examine_start(bdev);
@ -1417,16 +1557,58 @@ vbdev_ocf_examine_disk(struct spdk_bdev *bdev)
if (!strcmp(bdev_name, vbdev->cache.name)) {
examine_start(bdev);
register_vbdev(vbdev, examine_done, bdev);
created_from_config = true;
continue;
}
if (!strcmp(bdev_name, vbdev->core.name)) {
examine_start(bdev);
register_vbdev(vbdev, examine_done, bdev);
break;
examine_done(0, NULL, bdev);
return;
}
}
examine_done(0, NULL, bdev);
/* If devices is discovered during config we do not check for metadata */
if (created_from_config) {
examine_done(0, NULL, bdev);
return;
}
/* Metadata probe path
* We create temporary OCF volume and a temporary base structure
* to use them for ocf_metadata_probe() and for bottom adapter IOs
* Then we get UUIDs of core devices an create configurations based on them */
ctx = calloc(1, sizeof(*ctx));
if (!ctx) {
examine_done(-ENOMEM, NULL, bdev);
return;
}
ctx->base.bdev = bdev;
ctx->refcnt = 1;
rc = spdk_bdev_open(ctx->base.bdev, true, NULL, NULL, &ctx->base.desc);
if (rc) {
ctx->result = rc;
examine_ctx_put(ctx);
return;
}
rc = ocf_ctx_volume_create(vbdev_ocf_ctx, &ctx->volume, NULL, SPDK_OBJECT);
if (rc) {
ctx->result = rc;
examine_ctx_put(ctx);
return;
}
rc = ocf_volume_open(ctx->volume, &ctx->base);
if (rc) {
ctx->result = rc;
examine_ctx_put(ctx);
return;
}
ocf_metadata_probe(vbdev_ocf_ctx, ctx->volume, metadata_probe_cb, ctx);
}
static int