bdev: Generalize buffer allocation

Make the buffer allocation work for all types of
commands, not just read.

Change-Id: I72d8f67a724566630e7c4a74759fcb08449f7de4
Signed-off-by: Ben Walker <benjamin.walker@intel.com>

include/spdk_internal/bdev.h

@@ -157,15 +157,14 @@ struct spdk_bdev_io {
 	/** Generation value for each I/O. */
 	uint32_t gencnt;
 
+	/** bdev allocated memory associated with this request */
+	void *buf;
+
 	/** Enumerated value representing the I/O type. */
 	enum spdk_bdev_io_type type;
 
 	union {
 		struct {
-
-			/** The unaligned buf originally allocated. */
-			void *buf_unaligned;
-
 			/** For basic read case, use our own iovec element. */
 			struct iovec iov;
 
@@ -175,14 +174,11 @@ struct spdk_bdev_io {
 			/** For SG buffer cases, number of iovecs in iovec array. */
 			int iovcnt;
 
-			/** For SG buffer cases, total size of data to be transferred. */
+			/** Total size of data to be transferred. */
 			size_t len;
 
 			/** Starting offset (in bytes) of the blockdev for this I/O. */
 			uint64_t offset;
-
-			/** Indicate whether the blockdev layer to put buf or not. */
-			bool put_buf;
 		} read;
 		struct {
 			/** For basic write case, use our own iovec element */
@@ -194,7 +190,7 @@ struct spdk_bdev_io {
 			/** For SG buffer cases, number of iovecs in iovec array. */
 			int iovcnt;
 
-			/** For SG buffer cases, total size of data to be transferred. */
+			/** Total size of data to be transferred. */
 			size_t len;
 
 			/** Starting offset (in bytes) of the blockdev for this I/O. */

lib/bdev/bdev.c

@@ -120,10 +120,9 @@ spdk_bdev_io_set_buf(struct spdk_bdev_io *bdev_io, void *buf)
 	assert(buf != NULL);
 	assert(bdev_io->u.read.iovs != NULL);
 
-	bdev_io->u.read.buf_unaligned = buf;
+	bdev_io->buf = buf;
 	bdev_io->u.read.iovs[0].iov_base = (void *)((unsigned long)((char *)buf + 512) & ~511UL);
 	bdev_io->u.read.iovs[0].iov_len = bdev_io->u.read.len;
-	bdev_io->u.read.put_buf = true;
 	bdev_io->get_buf_cb(bdev_io->ch->channel, bdev_io);
 }
 
@@ -139,7 +138,7 @@ spdk_bdev_io_put_buf(struct spdk_bdev_io *bdev_io)
 	assert(bdev_io->u.read.iovcnt == 1);
 
 	length = bdev_io->u.read.len;
-	buf = bdev_io->u.read.buf_unaligned;
+	buf = bdev_io->buf;
 
 	if (length <= SPDK_BDEV_SMALL_BUF_MAX_SIZE) {
 		pool = g_buf_small_pool;
@@ -344,7 +343,7 @@ spdk_bdev_put_io(struct spdk_bdev_io *bdev_io)
 		return;
 	}
 
-	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ && bdev_io->u.read.put_buf) {
+	if (bdev_io->buf != NULL) {
 		spdk_bdev_io_put_buf(bdev_io);
 	}
 
@@ -476,9 +475,7 @@ spdk_bdev_get_child_io(struct spdk_bdev_io *parent,
 
 	child->type = parent->type;
 	memcpy(&child->u, &parent->u, sizeof(child->u));
-	if (child->type == SPDK_BDEV_IO_TYPE_READ) {
+	child->buf = NULL;
-		child->u.read.put_buf = false;
-	}
 	child->get_buf_cb = NULL;
 	child->parent = parent;
 
@@ -580,7 +577,6 @@ spdk_bdev_read(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 	bdev_io->u.read.iovcnt = 1;
 	bdev_io->u.read.len = nbytes;
 	bdev_io->u.read.offset = offset;
-	bdev_io->u.read.put_buf = false;
 	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);
 
 	rc = spdk_bdev_io_submit(bdev_io);
@@ -619,7 +615,6 @@ spdk_bdev_readv(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 	bdev_io->u.read.iovcnt = iovcnt;
 	bdev_io->u.read.len = nbytes;
 	bdev_io->u.read.offset = offset;
-	bdev_io->u.read.put_buf = false;
 	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);
 
 	rc = spdk_bdev_io_submit(bdev_io);

lib/bdev/malloc/blockdev_malloc.c

@@ -280,7 +280,6 @@ static int _blockdev_malloc_submit_request(struct spdk_io_channel *ch, struct sp
 				((struct malloc_disk *)bdev_io->bdev->ctxt)->malloc_buf +
 				bdev_io->u.read.offset;
 			bdev_io->u.read.iovs[0].iov_len = bdev_io->u.read.len;
-			bdev_io->u.read.put_buf = false;
 			spdk_bdev_io_complete(spdk_bdev_io_from_ctx(bdev_io->driver_ctx),
 					      SPDK_BDEV_IO_STATUS_SUCCESS);
 			return 0;