feat(snapshot): get lba from snapshot which is ancestor of current blob

Signed-off-by: Hrudaya <[email protected]>
openebs · Dec 21, 2023 · be46585 · be46585
1 parent 226fad7
commit be46585
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Showing 2 changed files with 47 additions and 3 deletions.
diff --git a/lib/blob/blobstore.c b/lib/blob/blobstore.c
@@ -2777,6 +2777,42 @@ blob_calculate_lba_and_lba_count(struct spdk_blob *blob, uint64_t io_unit, uint6
 	}
 }
 
+static inline bool
+blob_ancestor_calc_lba_and_lba_count(struct spdk_blob *blob, uint64_t io_unit, uint64_t length,
+				     uint64_t *lba, uint64_t *lba_count)
+{
+	struct spdk_blob *orig_blob = blob;
+	*lba_count = length;
+	if (!bs_io_unit_is_allocated(orig_blob, io_unit)) {
+		if (orig_blob->parent_id == SPDK_BLOBID_INVALID) {
+			goto error;
+		} else {
+			while (blob->parent_id != SPDK_BLOBID_INVALID) {
+				spdk_blob_id blob_id = blob->parent_id;
+				blob = blob_lookup(blob->bs, blob_id);
+				if (blob == NULL) {
+					return false;
+				} else {
+					if (!bs_io_unit_is_allocated(blob, io_unit)) {
+						continue;
+					}
+					*lba = bs_blob_io_unit_to_lba(blob, io_unit);
+					return true;
+				}
+			}
+			goto error;
+		}
+	} else {
+		*lba = bs_blob_io_unit_to_lba(blob, io_unit);
+		return true;
+	}
+error:
+	assert(orig_blob->back_bs_dev != NULL);
+	*lba = bs_io_unit_to_back_dev_lba(orig_blob, io_unit);
+	*lba_count = bs_io_unit_to_back_dev_lba(orig_blob, *lba_count);
+	return false;
+}
+
 struct op_split_ctx {
 	struct spdk_blob *blob;
 	struct spdk_io_channel *channel;
@@ -3239,13 +3275,17 @@ blob_request_submit_rw_iov(struct spdk_blob *blob, struct spdk_io_channel *_chan
 
 			return;
 		}
-
-		is_allocated = blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
+		if (read & ((ext_io_flags & FLAG_READ_ALLOCATED) == FLAG_READ_ALLOCATED)) {
+			is_allocated = blob_ancestor_calc_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
+		} else {
+			is_allocated = blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
+		}
 
 		if (read) {
 			spdk_bs_sequence_t *seq;
 
-			if (ext_io_flags & SPDK_NVME_IO_FLAGS_UNWRITTEN_READ_FAIL) {
+			if (((ext_io_flags & FLAG_READ_ALLOCATED) == FLAG_READ_ALLOCATED) &
+			    SPDK_NVME_IO_FLAGS_UNWRITTEN_READ_FAIL) {
 				if (!is_allocated) {
 					/* ETXTBSY was chosen to indicate read of unwritten block.
 					 * It is not used by SPDK, so it should be fine. */

diff --git a/lib/blob/blobstore.h b/lib/blob/blobstore.h
@@ -230,6 +230,10 @@ enum spdk_blob_op_type {
 	SPDK_BLOB_READV,
 };
 
+/** ext io flag type */
+enum spdk_blob_ext_io_type {
+	FLAG_READ_ALLOCATED = 1,
+};
 /* back bs_dev */
 
 #define BLOB_SNAPSHOT "SNAP"