From 4cca082e68967ba2d63b90f840c9ed7313bd782c Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Mon, 27 Mar 2017 17:07:41 +0800 Subject: [PATCH] tcmu: Fix wrongly calculating of the base_command_size The t_data_nents and t_bidi_data_nents are the numbers of the segments, but it couldn't be sure the block size equals to size of the segment. For the worst case, all the blocks are discontiguous and there will need the same number of iovecs, that's to say: blocks == iovs. So here just set the number of iovs to block count needed by tcmu cmd. Tested-by: Ilias Tsitsimpis Reviewed-by: Mike Christie Signed-off-by: Xiubo Li Cc: stable@vger.kernel.org # 3.18+ Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_user.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index e58dfd4fe448d..9885d1b521fe8 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -408,6 +408,13 @@ static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd) return data_length; } +static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd) +{ + size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd); + + return data_length / DATA_BLOCK_SIZE; +} + static sense_reason_t tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) { @@ -435,8 +442,7 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) * expensive to tell how many regions are freed in the bitmap */ base_command_size = max(offsetof(struct tcmu_cmd_entry, - req.iov[se_cmd->t_bidi_data_nents + - se_cmd->t_data_nents]), + req.iov[tcmu_cmd_get_block_cnt(tcmu_cmd)]), sizeof(struct tcmu_cmd_entry)); command_size = base_command_size + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); -- 2.39.5