blobstore: freeze I/O during resize

Signed-off-by: Piotr Pelplinski <piotr.pelplinski@intel.com>
Change-Id: I23c34d4dcb542aa9ab3fa8cb734cf9cc0e0fc5da

Reviewed-on: https://review.gerrithub.io/409144
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

include/spdk/blob.h

@@ -534,6 +534,7 @@ void spdk_bs_open_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
 /**
  * Resize a blob to 'sz' clusters. These changes are not persisted to disk until
  * spdk_bs_md_sync_blob() is called.
+ * If called before previous resize finish, it will fail with errno -EBUSY
  *
  * \param blob Blob to resize.
  * \param sz The new number of clusters.

lib/blob/blobstore.c

@@ -4441,10 +4441,55 @@ void spdk_bs_inflate_blob(struct spdk_blob_store *bs, struct spdk_io_channel *ch
 /* END spdk_bs_inflate_blob */
 
 /* START spdk_blob_resize */
+struct spdk_bs_resize_ctx {
+	spdk_blob_op_complete cb_fn;
+	void *cb_arg;
+	struct spdk_blob *blob;
+	uint64_t sz;
+	int rc;
+};
+
+static void
+_spdk_bs_resize_unfreeze_cpl(void *cb_arg, int rc)
+{
+	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
+
+	if (rc != 0) {
+		SPDK_ERRLOG("Unfreeze failed, rc=%d\n", rc);
+	}
+
+	if (ctx->rc != 0) {
+		SPDK_ERRLOG("Unfreeze failed, ctx->rc=%d\n", ctx->rc);
+		rc = ctx->rc;
+	}
+
+	ctx->blob->resize_in_progress = false;
+
+	ctx->cb_fn(ctx->cb_arg, rc);
+	free(ctx);
+}
+
+static void
+_spdk_bs_resize_freeze_cpl(void *cb_arg, int rc)
+{
+	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
+
+	if (rc != 0) {
+		ctx->blob->resize_in_progress = false;
+		ctx->cb_fn(ctx->cb_arg, rc);
+		free(ctx);
+		return;
+	}
+
+	ctx->rc = _spdk_blob_resize(ctx->blob, ctx->sz);
+
+	_spdk_blob_unfreeze_io(ctx->blob, _spdk_bs_resize_unfreeze_cpl, ctx);
+}
+
 void
 spdk_blob_resize(struct spdk_blob *blob, uint64_t sz, spdk_blob_op_complete cb_fn, void *cb_arg)
 {
-	int			rc;
+	struct spdk_bs_resize_ctx *ctx;
 
 	_spdk_blob_verify_md_op(blob);
 
@@ -4460,8 +4505,23 @@ spdk_blob_resize(struct spdk_blob *blob, uint64_t sz, spdk_blob_op_complete cb_f
 		return;
 	}
 
-	rc = _spdk_blob_resize(blob, sz);
+	if (blob->resize_in_progress) {
-	cb_fn(cb_arg, rc);
+		cb_fn(cb_arg, -EBUSY);
+		return;
+	}
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (!ctx) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	blob->resize_in_progress = true;
+	ctx->cb_fn = cb_fn;
+	ctx->cb_arg = cb_arg;
+	ctx->blob = blob;
+	ctx->sz = sz;
+	_spdk_blob_freeze_io(blob, _spdk_bs_resize_freeze_cpl, ctx);
 }
 
 /* END spdk_blob_resize */

lib/blob/blobstore.h

@@ -149,6 +149,7 @@ struct spdk_blob {
 	TAILQ_ENTRY(spdk_blob) link;
 
 	uint32_t frozen_refcnt;
+	bool resize_in_progress;
 };
 
 struct spdk_blob_store {