scst: Introduce for_each_sg() in scst_adjust_sg()

Make scst_adjust_sg() slightly easier to read by using for_each_sg()
to iterate over the elements of the scatter/gather-list.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>




git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4910 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Vladislav Bolkhovitin
2013-07-03 04:37:53 +00:00
parent cf43cffd81
commit 2755c02421

View File

@@ -2786,41 +2786,38 @@ next:
static void scst_adjust_sg(struct scst_cmd *cmd, struct scatterlist *sg, static void scst_adjust_sg(struct scst_cmd *cmd, struct scatterlist *sg,
int *sg_cnt, int adjust_len) int *sg_cnt, int adjust_len)
{ {
int i, j, l; struct scatterlist *sgi;
int i, l;
TRACE_ENTRY(); TRACE_ENTRY();
l = 0; l = 0;
for (i = 0, j = 0; i < *sg_cnt; i++, j++) { for_each_sg(sg, sgi, *sg_cnt, i) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24) #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
TRACE_DBG("i %d, j %d, sg_cnt %d, sg %p, page_link %lx", i, j, TRACE_DBG("i %d, sg_cnt %d, sg %p, page_link %lx", i,
*sg_cnt, sg, sg[j].page_link); *sg_cnt, sg, sgi->page_link);
#else #else
TRACE_DBG("i %d, j %d, sg_cnt %d, sg %p, page_link %lx", i, j, TRACE_DBG("i %d, sg_cnt %d, sg %p, page_link %lx", i,
*sg_cnt, sg, 0UL); *sg_cnt, sg, 0UL);
#endif #endif
if (unlikely(sg_is_chain(&sg[j]))) { l += sgi->length;
sg = sg_chain_ptr(&sg[j]);
j = 0;
}
l += sg[j].length;
if (l >= adjust_len) { if (l >= adjust_len) {
int left = adjust_len - (l - sg[j].length); int left = adjust_len - (l - sgi->length);
#ifdef CONFIG_SCST_DEBUG #ifdef CONFIG_SCST_DEBUG
TRACE(TRACE_SG_OP|TRACE_MEMORY, "cmd %p (tag %llu), " TRACE(TRACE_SG_OP|TRACE_MEMORY, "cmd %p (tag %llu), "
"sg %p, sg_cnt %d, adjust_len %d, i %d, j %d, " "sg %p, sg_cnt %d, adjust_len %d, i %d, "
"sg[j].length %d, left %d", "sg[j].length %d, left %d",
cmd, (long long unsigned int)cmd->tag, cmd, (long long unsigned int)cmd->tag,
sg, *sg_cnt, adjust_len, i, j, sg, *sg_cnt, adjust_len, i,
sg[j].length, left); sgi->length, left);
#endif #endif
cmd->p_orig_sg_cnt = sg_cnt; cmd->p_orig_sg_cnt = sg_cnt;
cmd->orig_sg_cnt = *sg_cnt; cmd->orig_sg_cnt = *sg_cnt;
cmd->orig_sg_entry = &sg[j]; cmd->orig_sg_entry = sgi;
cmd->orig_entry_offs = sg[j].offset; cmd->orig_entry_offs = sgi->offset;
cmd->orig_entry_len = sg[j].length; cmd->orig_entry_len = sgi->length;
*sg_cnt = (left > 0) ? i+1 : i; *sg_cnt = (left > 0) ? i+1 : i;
sg[j].length = left; sgi->length = left;
cmd->sg_buff_modified = 1; cmd->sg_buff_modified = 1;
break; break;
} }