I was a little sloppy in dealing with the zero_page case in
write_partial_message_data(), and I believe it led to some
problems I saw in testing. So I've modified it so the length
and last_piece values are calculated correctly, and that's
reflected in this updated version of the patch.
-Alex
Basically all cases in write_partial_msg_pages() use the cursor, and
as a result we can simplify that function quite a bit.
Signed-off-by: Alex Elder <[email protected]>
---
v2: fixed length and last_piece calculation for zero_page
net/ceph/messenger.c | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index b7ddf2b..6818c2f 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1466,7 +1466,6 @@ static int write_partial_message_data(struct
ceph_connection *con)
unsigned int data_len = le32_to_cpu(msg->hdr.data_len);
bool do_datacrc = !con->msgr->nocrc;
int ret;
- int total_max_write;
dout("%s %p msg %p page %d offset %d\n", __func__,
con, msg, msg_pos->page, msg_pos->page_pos);
@@ -1480,36 +1479,29 @@ static int write_partial_message_data(struct
ceph_connection *con)
* been revoked, so use the zero page.
*/
while (data_len > msg_pos->data_pos) {
- struct page *page = NULL;
+ struct page *page;
size_t page_offset;
size_t length;
- bool use_cursor = false;
- bool last_piece = true; /* preserve existing behavior */
-
- total_max_write = data_len - msg_pos->data_pos;
+ bool last_piece;
if (ceph_msg_has_pages(msg)) {
- use_cursor = true;
page = ceph_msg_data_next(&msg->p, &page_offset,
&length, &last_piece);
} else if (ceph_msg_has_pagelist(msg)) {
- use_cursor = true;
page = ceph_msg_data_next(&msg->l, &page_offset,
&length, &last_piece);
#ifdef CONFIG_BLOCK
} else if (ceph_msg_has_bio(msg)) {
- use_cursor = true;
page = ceph_msg_data_next(&msg->b, &page_offset,
&length, &last_piece);
#endif
} else {
- page = zero_page;
- }
- if (!use_cursor) {
- length = min_t(int, PAGE_SIZE - msg_pos->page_pos,
- total_max_write);
+ unsigned int resid = data_len - msg_pos->data_pos;
+ page = zero_page;
page_offset = msg_pos->page_pos;
+ length = min(resid, PAGE_SIZE - page_offset);
+ last_piece = length == resid;
}
if (do_datacrc && !msg_pos->did_page_crc) {
u32 crc = le32_to_cpu(msg->footer.data_crc);
--
1.7.9.5
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