Commit 751691d2 authored by Jim Harris's avatar Jim Harris
Browse files

blob: use spdk_bs_open_blob from spdk_bs_delete_blob 



This ensures all blob-loading functionality goes through
the single spdk_bs_open_blob function which will simplify
some upcoming changes around managing global metadata
state from multiple threads.

This will also help prevent races where a delete operation
has started followed by an open on the blob that is
being deleted.  Those specific changes will be in an
upcoming patch.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I17e995145ab23068b816b44c33483b0708f5f563

Reviewed-on: https://review.gerrithub.io/391486


Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 2ba5607e

lib/blob/blobstore.c

+61 −26
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 


static int spdk_bs_register_md_thread(struct spdk_blob_store *bs);

static int spdk_bs_unregister_md_thread(struct spdk_blob_store *bs);

static void _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno);



static inline size_t

divide_round_up(size_t num, size_t divisor)
@@ -2645,67 +2646,93 @@ spdk_blob_resize(struct spdk_blob *_blob, uint64_t sz) 
/* START spdk_bs_delete_blob */



static void

_spdk_bs_delete_blob_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)

_spdk_bs_delete_close_cpl(void *cb_arg, int bserrno)

{

	struct spdk_blob_data *blob = cb_arg;

	spdk_bs_sequence_t *seq = cb_arg;



	spdk_bs_sequence_finish(seq, bserrno);

}



static void

_spdk_bs_delete_persist_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)

{

	struct spdk_blob *_blob = cb_arg;

	struct spdk_blob_data *blob = __blob_to_data(_blob);



	if (bserrno != 0) {

		/*

		 * We already removed this blob from the blobstore tailq, so

		 *  we need to free it here since this is the last reference

		 *  to it.

		 */

		_spdk_blob_free(blob);

		_spdk_bs_delete_close_cpl(seq, bserrno);

		return;

	}



	spdk_bs_sequence_finish(seq, bserrno);

	/*

	 * This will immediately decrement the ref_count and call

	 *  the completion routine since the metadata state is clean.

	 *  By calling spdk_blob_close, we reduce the number of call

	 *  points into code that touches the blob->open_ref count

	 *  and the blobstore's blob list.

	 */

	spdk_blob_close(_blob, _spdk_bs_delete_close_cpl, seq);

}



static void

_spdk_bs_delete_open_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)

_spdk_bs_delete_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)

{

	struct spdk_blob_data *blob = cb_arg;

	spdk_bs_sequence_t *seq = cb_arg;

	struct spdk_blob_data *blob = __blob_to_data(_blob);



	/* If the blob have crc error, we just return NULL. */

	if (blob == NULL) {

	if (bserrno != 0) {

		spdk_bs_sequence_finish(seq, bserrno);

		return;

	}



	if (blob->open_ref > 1) {

		/*

		 * Someone has this blob open (besides this delete context).

		 *  Decrement the ref count directly and return -EBUSY.

		 */

		blob->open_ref--;

		spdk_bs_sequence_finish(seq, -EBUSY);

		return;

	}



	/*

	 * Remove the blob from the blob_store list now, to ensure it does not

	 *  get returned after this point by _spdk_blob_lookup().

	 */

	TAILQ_REMOVE(&blob->bs->blobs, blob, link);

	blob->state = SPDK_BLOB_STATE_DIRTY;

	blob->active.num_pages = 0;

	_spdk_resize_blob(blob, 0);



	_spdk_blob_persist(seq, blob, _spdk_bs_delete_blob_cpl, blob);

	_spdk_blob_persist(seq, blob, _spdk_bs_delete_persist_cpl, _blob);

}



void

spdk_bs_delete_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,

		    spdk_blob_op_complete cb_fn, void *cb_arg)

{

	struct spdk_blob_data	*blob;

	struct spdk_bs_cpl	cpl;

	spdk_bs_sequence_t 	*seq;



	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Deleting blob %lu\n", blobid);



	blob = _spdk_blob_lookup(bs, blobid);

	if (blob) {

		assert(blob->open_ref > 0);

		cb_fn(cb_arg, -EINVAL);

		return;

	}



	blob = _spdk_blob_alloc(bs, blobid);

	if (!blob) {

		cb_fn(cb_arg, -ENOMEM);

		return;

	}



	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;

	cpl.u.blob_basic.cb_fn = cb_fn;

	cpl.u.blob_basic.cb_arg = cb_arg;



	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);

	if (!seq) {

		_spdk_blob_free(blob);

		cb_fn(cb_arg, -ENOMEM);

		return;

	}



	_spdk_blob_load(seq, blob, _spdk_bs_delete_open_cpl, blob);

	spdk_bs_open_blob(bs, blobid, _spdk_bs_delete_open_cpl, seq);

}



/* END spdk_bs_delete_blob */
@@ -2833,7 +2860,15 @@ _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno) 
	struct spdk_blob_data *blob = cb_arg;



	if (blob->open_ref == 0) {

		/*

		 * Blobs with active.num_pages == 0 are deleted blobs.

		 *  these blobs are removed from the blob_store list

		 *  when the deletion process starts - so don't try to

		 *  remove them again.

		 */

		if (blob->active.num_pages > 0) {

			TAILQ_REMOVE(&blob->bs->blobs, blob, link);

		}

		_spdk_blob_free(blob);

	}