This patch gathers a few small changes in "net/ceph/messenger.c":
out_msg_pos_next()
- small logic change that mostly affects indentation
write_partial_msg_pages().
- use a local variable trail_off to represent the offset into
a message of the trail portion of the data (if present)
- once we are in the trail portion we will always be there, so we
don't always need to check against our data position
- avoid computing len twice after we've reached the trail
- get rid of the variable tmpcrc, which is not needed
- trail_off and trail_len never change so mark them const
- update some comments
read_partial_message_bio()
- bio_iovec_idx() will never return an error, so don't bother
checking for it
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
net/ceph/messenger.c | 63
+++++++++++++++++++++++++--------------------------
1 file changed, 31 insertions(+), 32 deletions(-)
Index: b/net/ceph/messenger.c
===================================================================
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -931,21 +931,23 @@ static void out_msg_pos_next(struct ceph
con->out_msg_pos.data_pos += sent;
con->out_msg_pos.page_pos += sent;
- if (sent == len) {
- con->out_msg_pos.page_pos = 0;
- con->out_msg_pos.page++;
- con->out_msg_pos.did_page_crc = false;
- if (in_trail)
- list_move_tail(&page->lru,
- &msg->trail->head);
- else if (msg->pagelist)
- list_move_tail(&page->lru,
- &msg->pagelist->head);
+ if (sent < len)
+ return;
+
+ BUG_ON(sent != len);
+ con->out_msg_pos.page_pos = 0;
+ con->out_msg_pos.page++;
+ con->out_msg_pos.did_page_crc = false;
+ if (in_trail)
+ list_move_tail(&page->lru,
+ &msg->trail->head);
+ else if (msg->pagelist)
+ list_move_tail(&page->lru,
+ &msg->pagelist->head);
#ifdef CONFIG_BLOCK
- else if (msg->bio)
- iter_bio_next(&msg->bio_iter, &msg->bio_seg);
+ else if (msg->bio)
+ iter_bio_next(&msg->bio_iter, &msg->bio_seg);
#endif
- }
}
/*
@@ -964,30 +966,31 @@ static int write_partial_msg_pages(struc
int ret;
int total_max_write;
bool in_trail = false;
- size_t trail_len = (msg->trail ? msg->trail->length : 0);
+ const size_t trail_len = (msg->trail ? msg->trail->length : 0);
+ const size_t trail_off = data_len - trail_len;
dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
con, msg, con->out_msg_pos.page, msg->nr_pages,
con->out_msg_pos.page_pos);
+ /*
+ * Iterate through each page that contains data to be
+ * written, and send as much as possible for each.
+ *
+ * If we are calculating the data crc (the default), we will
+ * need to map the page. If we have no pages, they have
+ * been revoked, so use the zero page.
+ */
while (data_len > con->out_msg_pos.data_pos) {
struct page *page = NULL;
int max_write = PAGE_SIZE;
int bio_offset = 0;
- total_max_write = data_len - trail_len -
- con->out_msg_pos.data_pos;
-
- /*
- * if we are calculating the data crc (the default), we need
- * to map the page. if our pages[] has been revoked, use the
- * zero page.
- */
-
- /* have we reached the trail part of the data? */
- if (con->out_msg_pos.data_pos >= data_len - trail_len) {
- in_trail = true;
+ in_trail = in_trail || con->out_msg_pos.data_pos >= trail_off;
+ if (!in_trail)
+ total_max_write = trail_off - con->out_msg_pos.data_pos;
+ if (in_trail) {
total_max_write = data_len - con->out_msg_pos.data_pos;
page = list_first_entry(&msg->trail->head,
@@ -1014,14 +1017,13 @@ static int write_partial_msg_pages(struc
if (do_datacrc && !con->out_msg_pos.did_page_crc) {
void *base;
- u32 crc;
- u32 tmpcrc = le32_to_cpu(msg->footer.data_crc);
+ u32 crc = le32_to_cpu(msg->footer.data_crc);
char *kaddr;
kaddr = kmap(page);
BUG_ON(kaddr == NULL);
base = kaddr + con->out_msg_pos.page_pos + bio_offset;
- crc = crc32c(tmpcrc, base, len);
+ crc = crc32c(crc, base, len);
msg->footer.data_crc = cpu_to_le32(crc);
con->out_msg_pos.did_page_crc = true;
}
@@ -1726,9 +1728,6 @@ static int read_partial_message_bio(stru
void *p;
int ret, left;
- if (IS_ERR(bv))
- return PTR_ERR(bv);
-
left = min((int)(data_len - con->in_msg_pos.data_pos),
(int)(bv->bv_len - con->in_msg_pos.page_pos));
--
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