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authorRoland Dreier <roland@purestorage.com>2012-03-30 11:29:15 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2012-04-14 17:40:32 -0700
commit957525a2424aad367d6e0efb64e440b2b37fa5cd (patch)
treedc56eaa7a6e60ad674059d110e6d4145adb55efd /drivers
parent6f9e7f01b69bc2d6021e4ab827e1fd78c82cbc52 (diff)
downloadlinux-957525a2424aad367d6e0efb64e440b2b37fa5cd.tar.bz2
target: Remove transport_do_task_sg_chain() and associated detritus
Now that all fabrics are converted over to using se_cmd->t_data_sg directly, we can drop the task sg chaining support. With the modern memory allocation in target core, task sg chaining is needless overhead -- we would split up the main cmd sglist into pieces, and then splice those pieces back together instead of just using the original list directly. Signed-off-by: Roland Dreier <roland@purestorage.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/target/target_core_transport.c70
1 files changed, 0 insertions, 70 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index db05c75864e0..9fdc708d5040 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -3699,76 +3699,6 @@ static inline sector_t transport_limit_task_sectors(
return sectors;
}
-
-/*
- * This function can be used by HW target mode drivers to create a linked
- * scatterlist from all contiguously allocated struct se_task->task_sg[].
- * This is intended to be called during the completion path by TCM Core
- * when struct target_core_fabric_ops->check_task_sg_chaining is enabled.
- */
-void transport_do_task_sg_chain(struct se_cmd *cmd)
-{
- struct scatterlist *sg_first = NULL;
- struct scatterlist *sg_prev = NULL;
- int sg_prev_nents = 0;
- struct scatterlist *sg;
- struct se_task *task;
- u32 chained_nents = 0;
- int i;
-
- BUG_ON(!cmd->se_tfo->task_sg_chaining);
-
- /*
- * Walk the struct se_task list and setup scatterlist chains
- * for each contiguously allocated struct se_task->task_sg[].
- */
- list_for_each_entry(task, &cmd->t_task_list, t_list) {
- if (!task->task_sg)
- continue;
-
- if (!sg_first) {
- sg_first = task->task_sg;
- chained_nents = task->task_sg_nents;
- } else {
- sg_chain(sg_prev, sg_prev_nents, task->task_sg);
- chained_nents += task->task_sg_nents;
- }
- /*
- * For the padded tasks, use the extra SGL vector allocated
- * in transport_allocate_data_tasks() for the sg_prev_nents
- * offset into sg_chain() above.
- *
- * We do not need the padding for the last task (or a single
- * task), but in that case we will never use the sg_prev_nents
- * value below which would be incorrect.
- */
- sg_prev_nents = (task->task_sg_nents + 1);
- sg_prev = task->task_sg;
- }
- /*
- * Setup the starting pointer and total t_tasks_sg_linked_no including
- * padding SGs for linking and to mark the end.
- */
- cmd->t_tasks_sg_chained = sg_first;
- cmd->t_tasks_sg_chained_no = chained_nents;
-
- pr_debug("Setup cmd: %p cmd->t_tasks_sg_chained: %p and"
- " t_tasks_sg_chained_no: %u\n", cmd, cmd->t_tasks_sg_chained,
- cmd->t_tasks_sg_chained_no);
-
- for_each_sg(cmd->t_tasks_sg_chained, sg,
- cmd->t_tasks_sg_chained_no, i) {
-
- pr_debug("SG[%d]: %p page: %p length: %d offset: %d\n",
- i, sg, sg_page(sg), sg->length, sg->offset);
- if (sg_is_chain(sg))
- pr_debug("SG: %p sg_is_chain=1\n", sg);
- if (sg_is_last(sg))
- pr_debug("SG: %p sg_is_last=1\n", sg);
- }
-}
-EXPORT_SYMBOL(transport_do_task_sg_chain);
-
/*
* Break up cmd into chunks transport can handle
*/