Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a5d68ba8 authored by Xiubo Li's avatar Xiubo Li Committed by Nicholas Bellinger
Browse files

tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case 



For the bidirectional case, the Data-Out buffer blocks will always at
the head of the tcmu_cmd's bitmap, and before gathering the Data-In
buffer, first of all it should skip the Data-Out ones, or the device
supporting BIDI commands won't work.

Fixed: 26418649 ("target/user: Introduce data_bitmap, replace
		data_length/data_head/data_tail")
Reported-by: default avatarIlias Tsitsimpis <iliastsi@arrikto.com>
Tested-by: default avatarIlias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: default avatarXiubo Li <lixiubo@cmss.chinamobile.com>
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 1c99de98

drivers/target/target_core_user.c

+33 −15
Original line number Diff line number Diff line
@@ -311,24 +311,50 @@ static void free_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd) 
		   DATA_BLOCK_BITS);

}



static void gather_data_area(struct tcmu_dev *udev, unsigned long *cmd_bitmap,

		struct scatterlist *data_sg, unsigned int data_nents)

static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,

			     bool bidi)

{

	struct se_cmd *se_cmd = cmd->se_cmd;

	int i, block;

	int block_remaining = 0;

	void *from, *to;

	size_t copy_bytes, from_offset;

	struct scatterlist *sg;

	struct scatterlist *sg, *data_sg;

	unsigned int data_nents;

	DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS);



	bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS);



	if (!bidi) {

		data_sg = se_cmd->t_data_sg;

		data_nents = se_cmd->t_data_nents;

	} else {

		uint32_t count;



		/*

		 * For bidi case, the first count blocks are for Data-Out

		 * buffer blocks, and before gathering the Data-In buffer

		 * the Data-Out buffer blocks should be discarded.

		 */

		count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);

		while (count--) {

			block = find_first_bit(bitmap, DATA_BLOCK_BITS);

			clear_bit(block, bitmap);

		}



		data_sg = se_cmd->t_bidi_data_sg;

		data_nents = se_cmd->t_bidi_data_nents;

	}



	for_each_sg(data_sg, sg, data_nents, i) {

		int sg_remaining = sg->length;

		to = kmap_atomic(sg_page(sg)) + sg->offset;

		while (sg_remaining > 0) {

			if (block_remaining == 0) {

				block = find_first_bit(cmd_bitmap,

				block = find_first_bit(bitmap,

						DATA_BLOCK_BITS);

				block_remaining = DATA_BLOCK_SIZE;

				clear_bit(block, cmd_bitmap);

				clear_bit(block, bitmap);

			}

			copy_bytes = min_t(size_t, sg_remaining,

					block_remaining);
@@ -610,19 +636,11 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry * 
			       se_cmd->scsi_sense_length);

		free_data_area(udev, cmd);

	} else if (se_cmd->se_cmd_flags & SCF_BIDI) {

		DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS);



		/* Get Data-In buffer before clean up */

		bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS);

		gather_data_area(udev, bitmap,

			se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents);

		gather_data_area(udev, cmd, true);

		free_data_area(udev, cmd);

	} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {

		DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS);



		bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS);

		gather_data_area(udev, bitmap,

			se_cmd->t_data_sg, se_cmd->t_data_nents);

		gather_data_area(udev, cmd, false);

		free_data_area(udev, cmd);

	} else if (se_cmd->data_direction == DMA_TO_DEVICE) {

		free_data_area(udev, cmd);