mirror of https://gitee.com/openkylin/linux.git
IB/iser: set block queue_virt_boundary
The block layer can reliably guarantee that SG lists won't contain gaps (page unaligned) if a driver set the queue virt_boundary. With this setting the block layer will: - refuse merges if bios are not aligned to the virtual boundary - split bios/requests that are not aligned to the virtual boundary - or, bounce buffer SG_IOs that are not aligned to the virtual boundary Since iser is working in 4K page size, set the virt_boundary to 4K pages. With this setting, we can now safely remove the bounce buffering logic in iser. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Sagi Grimberg
Doug Ledford
parent
6c760b3dd5
commit
dd0107a089
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@ -762,9 +762,7 @@ iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *s
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stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
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stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
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stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
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stats->custom_length = 1;
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strcpy(stats->custom[0].desc, "fmr_unalign_cnt");
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stats->custom[0].value = conn->fmr_unalign_cnt;
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stats->custom_length = 0;
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}
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static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
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@ -969,6 +967,13 @@ static umode_t iser_attr_is_visible(int param_type, int param)
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return 0;
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}
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static int iscsi_iser_slave_alloc(struct scsi_device *sdev)
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{
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blk_queue_virt_boundary(sdev->request_queue, ~MASK_4K);
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return 0;
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}
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static struct scsi_host_template iscsi_iser_sht = {
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.module = THIS_MODULE,
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.name = "iSCSI Initiator over iSER",
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@ -982,6 +987,7 @@ static struct scsi_host_template iscsi_iser_sht = {
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.eh_target_reset_handler = iscsi_eh_recover_target,
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.target_alloc = iscsi_target_alloc,
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.use_clustering = DISABLE_CLUSTERING,
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.slave_alloc = iscsi_iser_slave_alloc,
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.proc_name = "iscsi_iser",
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.this_id = -1,
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.track_queue_depth = 1,
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@ -227,18 +227,13 @@ enum iser_data_dir {
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* @size: num entries of this sg
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* @data_len: total beffer byte len
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* @dma_nents: returned by dma_map_sg
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* @orig_sg: pointer to the original sg list (in case
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* we used a copy)
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* @orig_size: num entris of orig sg list
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*/
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struct iser_data_buf {
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struct scatterlist *sg;
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unsigned int size;
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unsigned long data_len;
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unsigned int dma_nents;
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struct scatterlist *orig_sg;
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unsigned int orig_size;
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};
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};
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/* fwd declarations */
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struct iser_device;
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@ -661,48 +661,14 @@ void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
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void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
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{
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int is_rdma_data_aligned = 1;
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int is_rdma_prot_aligned = 1;
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int prot_count = scsi_prot_sg_count(iser_task->sc);
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/* if we were reading, copy back to unaligned sglist,
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* anyway dma_unmap and free the copy
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*/
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if (iser_task->data[ISER_DIR_IN].orig_sg) {
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is_rdma_data_aligned = 0;
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iser_finalize_rdma_unaligned_sg(iser_task,
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&iser_task->data[ISER_DIR_IN],
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ISER_DIR_IN);
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}
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if (iser_task->data[ISER_DIR_OUT].orig_sg) {
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is_rdma_data_aligned = 0;
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iser_finalize_rdma_unaligned_sg(iser_task,
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&iser_task->data[ISER_DIR_OUT],
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ISER_DIR_OUT);
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}
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if (iser_task->prot[ISER_DIR_IN].orig_sg) {
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is_rdma_prot_aligned = 0;
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iser_finalize_rdma_unaligned_sg(iser_task,
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&iser_task->prot[ISER_DIR_IN],
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ISER_DIR_IN);
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}
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if (iser_task->prot[ISER_DIR_OUT].orig_sg) {
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is_rdma_prot_aligned = 0;
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iser_finalize_rdma_unaligned_sg(iser_task,
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&iser_task->prot[ISER_DIR_OUT],
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ISER_DIR_OUT);
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}
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if (iser_task->dir[ISER_DIR_IN]) {
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iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
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if (is_rdma_data_aligned)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->data[ISER_DIR_IN],
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DMA_FROM_DEVICE);
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if (prot_count && is_rdma_prot_aligned)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->data[ISER_DIR_IN],
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DMA_FROM_DEVICE);
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if (prot_count)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->prot[ISER_DIR_IN],
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DMA_FROM_DEVICE);
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@ -710,11 +676,10 @@ void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
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if (iser_task->dir[ISER_DIR_OUT]) {
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iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
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if (is_rdma_data_aligned)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->data[ISER_DIR_OUT],
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DMA_TO_DEVICE);
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if (prot_count && is_rdma_prot_aligned)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->data[ISER_DIR_OUT],
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DMA_TO_DEVICE);
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if (prot_count)
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iser_dma_unmap_task_data(iser_task,
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&iser_task->prot[ISER_DIR_OUT],
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DMA_TO_DEVICE);
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@ -88,113 +88,6 @@ int iser_assign_reg_ops(struct iser_device *device)
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return 0;
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}
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static void
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iser_free_bounce_sg(struct iser_data_buf *data)
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{
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struct scatterlist *sg;
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int count;
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for_each_sg(data->sg, sg, data->size, count)
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__free_page(sg_page(sg));
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kfree(data->sg);
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data->sg = data->orig_sg;
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data->size = data->orig_size;
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data->orig_sg = NULL;
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data->orig_size = 0;
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}
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static int
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iser_alloc_bounce_sg(struct iser_data_buf *data)
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{
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struct scatterlist *sg;
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struct page *page;
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unsigned long length = data->data_len;
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int i = 0, nents = DIV_ROUND_UP(length, PAGE_SIZE);
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sg = kcalloc(nents, sizeof(*sg), GFP_ATOMIC);
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if (!sg)
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goto err;
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sg_init_table(sg, nents);
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while (length) {
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u32 page_len = min_t(u32, length, PAGE_SIZE);
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page = alloc_page(GFP_ATOMIC);
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if (!page)
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goto err;
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sg_set_page(&sg[i], page, page_len, 0);
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length -= page_len;
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i++;
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}
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data->orig_sg = data->sg;
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data->orig_size = data->size;
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data->sg = sg;
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data->size = nents;
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return 0;
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err:
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for (; i > 0; i--)
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__free_page(sg_page(&sg[i - 1]));
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kfree(sg);
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return -ENOMEM;
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}
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static void
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iser_copy_bounce(struct iser_data_buf *data, bool to_buffer)
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{
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struct scatterlist *osg, *bsg = data->sg;
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void *oaddr, *baddr;
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unsigned int left = data->data_len;
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unsigned int bsg_off = 0;
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int i;
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for_each_sg(data->orig_sg, osg, data->orig_size, i) {
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unsigned int copy_len, osg_off = 0;
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oaddr = kmap_atomic(sg_page(osg)) + osg->offset;
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copy_len = min(left, osg->length);
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while (copy_len) {
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unsigned int len = min(copy_len, bsg->length - bsg_off);
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baddr = kmap_atomic(sg_page(bsg)) + bsg->offset;
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if (to_buffer)
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memcpy(baddr + bsg_off, oaddr + osg_off, len);
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else
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memcpy(oaddr + osg_off, baddr + bsg_off, len);
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kunmap_atomic(baddr - bsg->offset);
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osg_off += len;
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bsg_off += len;
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copy_len -= len;
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if (bsg_off >= bsg->length) {
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bsg = sg_next(bsg);
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bsg_off = 0;
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}
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}
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kunmap_atomic(oaddr - osg->offset);
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left -= osg_off;
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}
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}
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static inline void
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iser_copy_from_bounce(struct iser_data_buf *data)
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{
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iser_copy_bounce(data, false);
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}
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static inline void
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iser_copy_to_bounce(struct iser_data_buf *data)
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{
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iser_copy_bounce(data, true);
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}
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struct iser_fr_desc *
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iser_reg_desc_get_fr(struct ib_conn *ib_conn)
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{
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@ -238,62 +131,6 @@ iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
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{
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}
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/**
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* iser_start_rdma_unaligned_sg
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*/
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static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
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struct iser_data_buf *data,
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enum iser_data_dir cmd_dir)
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{
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struct ib_device *dev = iser_task->iser_conn->ib_conn.device->ib_device;
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int rc;
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rc = iser_alloc_bounce_sg(data);
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if (rc) {
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iser_err("Failed to allocate bounce for data len %lu\n",
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data->data_len);
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return rc;
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}
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if (cmd_dir == ISER_DIR_OUT)
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iser_copy_to_bounce(data);
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data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size,
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(cmd_dir == ISER_DIR_OUT) ?
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DMA_TO_DEVICE : DMA_FROM_DEVICE);
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if (!data->dma_nents) {
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iser_err("Got dma_nents %d, something went wrong...\n",
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data->dma_nents);
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rc = -ENOMEM;
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goto err;
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}
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return 0;
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err:
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iser_free_bounce_sg(data);
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return rc;
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}
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/**
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* iser_finalize_rdma_unaligned_sg
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*/
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void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
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struct iser_data_buf *data,
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enum iser_data_dir cmd_dir)
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{
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struct ib_device *dev = iser_task->iser_conn->ib_conn.device->ib_device;
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ib_dma_unmap_sg(dev, data->sg, data->size,
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(cmd_dir == ISER_DIR_OUT) ?
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DMA_TO_DEVICE : DMA_FROM_DEVICE);
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if (cmd_dir == ISER_DIR_IN)
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iser_copy_from_bounce(data);
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iser_free_bounce_sg(data);
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}
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#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0)
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/**
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@ -355,64 +192,6 @@ static int iser_sg_to_page_vec(struct iser_data_buf *data,
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return cur_page;
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}
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/**
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* iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned
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* for RDMA sub-list of a scatter-gather list of memory buffers, and returns
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* the number of entries which are aligned correctly. Supports the case where
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* consecutive SG elements are actually fragments of the same physcial page.
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*/
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static int iser_data_buf_aligned_len(struct iser_data_buf *data,
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struct ib_device *ibdev,
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unsigned sg_tablesize)
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{
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struct scatterlist *sg, *sgl, *next_sg = NULL;
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u64 start_addr, end_addr;
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int i, ret_len, start_check = 0;
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if (data->dma_nents == 1)
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return 1;
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sgl = data->sg;
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start_addr = ib_sg_dma_address(ibdev, sgl);
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if (unlikely(sgl[0].offset &&
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data->data_len >= sg_tablesize * PAGE_SIZE)) {
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iser_dbg("can't register length %lx with offset %x "
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"fall to bounce buffer\n", data->data_len,
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sgl[0].offset);
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return 0;
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}
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for_each_sg(sgl, sg, data->dma_nents, i) {
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if (start_check && !IS_4K_ALIGNED(start_addr))
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break;
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next_sg = sg_next(sg);
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if (!next_sg)
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break;
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end_addr = start_addr + ib_sg_dma_len(ibdev, sg);
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start_addr = ib_sg_dma_address(ibdev, next_sg);
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if (end_addr == start_addr) {
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start_check = 0;
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continue;
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} else
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start_check = 1;
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if (!IS_4K_ALIGNED(end_addr))
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break;
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}
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ret_len = (next_sg) ? i : i+1;
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if (unlikely(ret_len != data->dma_nents))
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iser_warn("rdma alignment violation (%d/%d aligned)\n",
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ret_len, data->dma_nents);
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return ret_len;
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}
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static void iser_data_buf_dump(struct iser_data_buf *data,
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struct ib_device *ibdev)
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{
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@ -483,31 +262,6 @@ iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
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return 0;
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}
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static int fall_to_bounce_buf(struct iscsi_iser_task *iser_task,
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struct iser_data_buf *mem,
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enum iser_data_dir cmd_dir)
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{
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struct iscsi_conn *iscsi_conn = iser_task->iser_conn->iscsi_conn;
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struct iser_device *device = iser_task->iser_conn->ib_conn.device;
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iscsi_conn->fmr_unalign_cnt++;
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if (iser_debug_level > 0)
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iser_data_buf_dump(mem, device->ib_device);
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/* unmap the command data before accessing it */
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iser_dma_unmap_task_data(iser_task, mem,
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(cmd_dir == ISER_DIR_OUT) ?
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DMA_TO_DEVICE : DMA_FROM_DEVICE);
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/* allocate copy buf, if we are writing, copy the */
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/* unaligned scatterlist, dma map the copy */
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if (iser_start_rdma_unaligned_sg(iser_task, mem, cmd_dir) != 0)
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return -ENOMEM;
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return 0;
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}
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/**
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* iser_reg_page_vec - Register physical memory
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*
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@ -779,26 +533,6 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
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return 0;
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}
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static int
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iser_handle_unaligned_buf(struct iscsi_iser_task *task,
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struct iser_data_buf *mem,
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enum iser_data_dir dir)
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{
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struct iser_conn *iser_conn = task->iser_conn;
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struct iser_device *device = iser_conn->ib_conn.device;
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int err, aligned_len;
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aligned_len = iser_data_buf_aligned_len(mem, device->ib_device,
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iser_conn->scsi_sg_tablesize);
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if (aligned_len != mem->dma_nents) {
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err = fall_to_bounce_buf(task, mem, dir);
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if (err)
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return err;
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}
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return 0;
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}
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static int
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iser_reg_prot_sg(struct iscsi_iser_task *task,
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struct iser_data_buf *mem,
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@ -841,10 +575,6 @@ int iser_reg_rdma_mem(struct iscsi_iser_task *task,
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bool use_dma_key;
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int err;
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err = iser_handle_unaligned_buf(task, mem, dir);
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if (unlikely(err))
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return err;
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|
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use_dma_key = (mem->dma_nents == 1 && !iser_always_reg &&
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scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL);
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@ -867,10 +597,6 @@ int iser_reg_rdma_mem(struct iscsi_iser_task *task,
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if (scsi_prot_sg_count(task->sc)) {
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mem = &task->prot[dir];
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err = iser_handle_unaligned_buf(task, mem, dir);
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if (unlikely(err))
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goto err_reg;
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err = iser_reg_prot_sg(task, mem, desc,
|
||||
use_dma_key, prot_reg);
|
||||
if (unlikely(err))
|
||||
|
|
|
|||
Loading…
Reference in New Issue