diff options
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_user.c | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 94f5154ac788..93de51fbe392 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -231,6 +231,23 @@ static inline size_t head_to_end(size_t head, size_t size) return size - head; } +static inline void new_iov(struct iovec **iov, int *iov_cnt, + struct tcmu_dev *udev) +{ + struct iovec *iovec; + + if (*iov_cnt != 0) + (*iov)++; + (*iov_cnt)++; + + iovec = *iov; + memset(iovec, 0, sizeof(struct iovec)); + + /* Even iov_base is relative to mb_addr */ + iovec->iov_base = (void __user *) udev->data_off + + udev->data_head; +} + #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size) static void alloc_and_scatter_data_area(struct tcmu_dev *udev, @@ -242,6 +259,10 @@ static void alloc_and_scatter_data_area(struct tcmu_dev *udev, size_t copy_bytes; struct scatterlist *sg; + if (data_nents == 0) + return; + + new_iov(iov, iov_cnt, udev); for_each_sg(data_sg, sg, data_nents, i) { copy_bytes = min_t(size_t, sg->length, head_to_end(udev->data_head, udev->data_size)); @@ -253,12 +274,7 @@ static void alloc_and_scatter_data_area(struct tcmu_dev *udev, tcmu_flush_dcache_range(to, copy_bytes); } - /* Even iov_base is relative to mb_addr */ - (*iov)->iov_len = copy_bytes; - (*iov)->iov_base = (void __user *) udev->data_off + - udev->data_head; - (*iov_cnt)++; - (*iov)++; + (*iov)->iov_len += copy_bytes; UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size); @@ -268,9 +284,8 @@ static void alloc_and_scatter_data_area(struct tcmu_dev *udev, copy_bytes = sg->length - copy_bytes; + new_iov(iov, iov_cnt, udev); (*iov)->iov_len = copy_bytes; - (*iov)->iov_base = (void __user *) udev->data_off + - udev->data_head; if (copy_data) { to = (void *) udev->mb_addr + @@ -279,8 +294,6 @@ static void alloc_and_scatter_data_area(struct tcmu_dev *udev, tcmu_flush_dcache_range(to, copy_bytes); } - (*iov_cnt)++; - (*iov)++; UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size); @@ -393,12 +406,10 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) * Must be a certain minimum size for response sense info, but * also may be larger if the iov array is large. * - * iovs = sgl_nents+1, for end-of-ring case, plus another 1 - * b/c size == offsetof one-past-element. + * 3 iovs since we can describe the whole continuous are using one + * for data, one for bidi and one more in the case of wrap. */ - base_command_size = max(offsetof(struct tcmu_cmd_entry, - req.iov[se_cmd->t_bidi_data_nents + - se_cmd->t_data_nents + 2]), + base_command_size = max(offsetof(struct tcmu_cmd_entry, req.iov[3]), sizeof(struct tcmu_cmd_entry)); command_size = base_command_size + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); |