Commit dd0a320c authored by Tomasz Zawadzki's avatar Tomasz Zawadzki
Browse files

lib/blob: Always persist at least single extent table desc 



Following changes are done in this patch:
1) _spdk_blob_serialize_extent_table now persists
at least single extent page. When num_extent_pages == 0.
2) Minimum valid size of ET descriptor is even without
extent_pages. This is a case when there are no EP,
but we still want to persist num_clusters in ET.
3) Taking above points, redone the loop for serializing
extent pages.
4) Make sure to mark blob dirty if any new extent pages
were allocted.

Signed-off-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: I81dc6cf2de2722bb49927ed42f4b9f31292f78c5
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/482847


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarPaul Luse <paul.e.luse@intel.com>
parent c177a3c8

lib/blob/blobstore.c

+18 −26
Original line number Diff line number Diff line
@@ -885,9 +885,8 @@ _spdk_blob_serialize_extent_table_entry(const struct spdk_blob *blob, 
	uint64_t i, et_idx;

	uint32_t extent_page, ep_len;



	/* The buffer must have room for at least one extent page */

	cur_sz = sizeof(struct spdk_blob_md_descriptor) + sizeof(desc->num_clusters) + sizeof(

			 desc->extent_page[0]);

	/* The buffer must have room for at least num_clusters entry */

	cur_sz = sizeof(struct spdk_blob_md_descriptor) + sizeof(desc->num_clusters);

	if (*remaining_sz < cur_sz) {

		*next_ep = start_ep;

		return;
@@ -898,39 +897,29 @@ _spdk_blob_serialize_extent_table_entry(const struct spdk_blob *blob, 


	desc->num_clusters = blob->active.num_clusters;



	extent_page = blob->active.extent_pages[start_ep];

	ep_len = 1;

	et_idx = 0;

	for (i = start_ep + 1; i < blob->active.num_extent_pages; i++) {

		/* Extent table entries contain md page offsets for extent pages.

		 * Zeroes represent unallocated extent pages, which are run-length-encoded.

		 */

		if (extent_page == 0 && blob->active.extent_pages[i] == 0) {

			ep_len++;

			continue;

		}

		desc->extent_page[et_idx].page_idx = extent_page;

		desc->extent_page[et_idx].num_pages = ep_len;

		et_idx++;



		cur_sz += sizeof(desc->extent_page[et_idx]);



		if (*remaining_sz < cur_sz) {

	for (i = start_ep; i < blob->active.num_extent_pages; i++) {

		if (*remaining_sz < cur_sz  + sizeof(desc->extent_page[0])) {

			/* If we ran out of buffer space, return */

			*next_ep = i;

			break;

		}



		extent_page = blob->active.extent_pages[i];

		ep_len = 1;

		/* Verify that next extent_page is unallocated */

		if (extent_page == 0 &&

		    (i + 1 < blob->active.num_extent_pages && blob->active.extent_pages[i + 1] == 0)) {

			ep_len++;

			continue;

		}



	if (*remaining_sz >= cur_sz) {

		desc->extent_page[et_idx].page_idx = extent_page;

		desc->extent_page[et_idx].num_pages = ep_len;

		et_idx++;



		*next_ep = blob->active.num_extent_pages;

		ep_len = 1;

		cur_sz += sizeof(desc->extent_page[et_idx]);

	}

	*next_ep = i;



	desc->length = sizeof(desc->num_clusters) + sizeof(desc->extent_page[0]) * et_idx;

	*remaining_sz -= sizeof(struct spdk_blob_md_descriptor) + desc->length;
@@ -948,7 +937,9 @@ _spdk_blob_serialize_extent_table(const struct spdk_blob *blob, 
	int					rc;



	last_extent_page = 0;

	while (last_extent_page < blob->active.num_extent_pages) {

	/* At least single extent table entry has to be always persisted.

	 * Such case occurs with num_extent_pages == 0. */

	while (last_extent_page <= blob->active.num_extent_pages) {

		_spdk_blob_serialize_extent_table_entry(blob, last_extent_page, &last_extent_page, buf,

							remaining_sz);
@@ -2007,6 +1998,7 @@ _spdk_blob_persist_write_extent_pages(spdk_bs_sequence_t *seq, void *cb_arg, int 
		/* Writing out new extent page for the first time. Either active extent pages is larger

		 * than clean extent pages or there was no extent page assigned due to thin provisioning. */

		if (i >= blob->clean.extent_pages_array_size || blob->clean.extent_pages[i] == 0) {

			blob->state = SPDK_BLOB_STATE_DIRTY;

			assert(spdk_bit_array_get(blob->bs->used_md_pages, extent_page_id));

			ctx->next_extent_page = i + 1;

			_spdk_blob_persist_write_extent_page(extent_page_id, i * SPDK_EXTENTS_PER_EP, ctx);