From f5db90bcf2c69d099f9d828a8104796f41de6bc5 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 11 Mar 2013 23:34:23 -0500 Subject: libceph: kill last of ceph_msg_pos The only remaining field in the ceph_msg_pos structure is did_page_crc. In the new cursor model of things that flag (or something like it) belongs in the cursor. Define a new field "need_crc" in the cursor (which applies to all types of data) and initialize it to true whenever a cursor is initialized. In write_partial_message_data(), the data CRC still will be computed as before, but it will check the cursor->need_crc field to determine whether it's needed. Any time the cursor is advanced to a new piece of a data item, need_crc will be set, and this will cause the crc for that entire piece to be accumulated into the data crc. In write_partial_message_data() the intermediate crc value is now held in a local variable so it doesn't have to be byte-swapped so many times. In read_partial_msg_data() we do something similar (but mainly for consistency there). With that, the ceph_msg_pos structure can go away, and it no longer needs to be passed as an argument to prepare_message_data(). This cleanup is related to: http://tracker.ceph.com/issues/4428 Signed-off-by: Alex Elder Reviewed-by: Josh Durgin diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index c76b228..686df5b 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -93,6 +93,7 @@ static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type) struct ceph_msg_data_cursor { size_t resid; /* bytes not yet consumed */ bool last_piece; /* now at last piece of data item */ + bool need_crc; /* new piece; crc update needed */ union { #ifdef CONFIG_BLOCK struct { /* bio */ @@ -156,10 +157,6 @@ struct ceph_msg { struct ceph_msgpool *pool; }; -struct ceph_msg_pos { - bool did_page_crc; /* true if we've calculated crc for current page */ -}; - /* ceph connection fault delay defaults, for exponential backoff */ #define BASE_DELAY_INTERVAL (HZ/2) #define MAX_DELAY_INTERVAL (5 * 60 * HZ) @@ -217,7 +214,6 @@ struct ceph_connection { struct ceph_msg *out_msg; /* sending message (== tail of out_sent) */ bool out_msg_done; - struct ceph_msg_pos out_msg_pos; struct kvec out_kvec[8], /* sending header/footer data */ *out_kvec_cur; @@ -231,7 +227,6 @@ struct ceph_connection { /* message in temps */ struct ceph_msg_header in_hdr; struct ceph_msg *in_msg; - struct ceph_msg_pos in_msg_pos; u32 in_front_crc, in_middle_crc, in_data_crc; /* calculated crc */ char in_tag; /* protocol control byte */ diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 19f9fff..eee7a87 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1002,6 +1002,7 @@ static void ceph_msg_data_cursor_init(struct ceph_msg_data *data, /* BUG(); */ break; } + data->cursor.need_crc = true; } /* @@ -1069,12 +1070,12 @@ static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) BUG(); break; } + data->cursor.need_crc = new_piece; return new_piece; } -static void prepare_message_data(struct ceph_msg *msg, - struct ceph_msg_pos *msg_pos) +static void prepare_message_data(struct ceph_msg *msg) { size_t data_len; @@ -1086,8 +1087,6 @@ static void prepare_message_data(struct ceph_msg *msg, /* Initialize data cursor */ ceph_msg_data_cursor_init(&msg->data, data_len); - - msg_pos->did_page_crc = false; } /* @@ -1186,7 +1185,7 @@ static void prepare_write_message(struct ceph_connection *con) /* is there a data payload? */ con->out_msg->footer.data_crc = 0; if (m->hdr.data_len) { - prepare_message_data(con->out_msg, &con->out_msg_pos); + prepare_message_data(con->out_msg); con->out_more = 1; /* data + footer will follow */ } else { /* no, queue up footer too and be done */ @@ -1388,8 +1387,7 @@ static void out_msg_pos_next(struct ceph_connection *con, struct page *page, size_t len, size_t sent) { struct ceph_msg *msg = con->out_msg; - struct ceph_msg_pos *msg_pos = &con->out_msg_pos; - bool need_crc = false; + bool need_crc; BUG_ON(!msg); BUG_ON(!sent); @@ -1401,7 +1399,6 @@ static void out_msg_pos_next(struct ceph_connection *con, struct page *page, return; BUG_ON(sent != len); - msg_pos->did_page_crc = false; } static void in_msg_pos_next(struct ceph_connection *con, size_t len, @@ -1444,9 +1441,8 @@ static int write_partial_message_data(struct ceph_connection *con) { struct ceph_msg *msg = con->out_msg; struct ceph_msg_data_cursor *cursor = &msg->data.cursor; - struct ceph_msg_pos *msg_pos = &con->out_msg_pos; bool do_datacrc = !con->msgr->nocrc; - int ret; + u32 crc; dout("%s %p msg %p\n", __func__, con, msg); @@ -1461,38 +1457,40 @@ static int write_partial_message_data(struct ceph_connection *con) * need to map the page. If we have no pages, they have * been revoked, so use the zero page. */ + crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0; while (cursor->resid) { struct page *page; size_t page_offset; size_t length; bool last_piece; + int ret; page = ceph_msg_data_next(&msg->data, &page_offset, &length, &last_piece); - if (do_datacrc && !msg_pos->did_page_crc) { - u32 crc = le32_to_cpu(msg->footer.data_crc); + if (do_datacrc && cursor->need_crc) crc = ceph_crc32c_page(crc, page, page_offset, length); - msg->footer.data_crc = cpu_to_le32(crc); - msg_pos->did_page_crc = true; - } ret = ceph_tcp_sendpage(con->sock, page, page_offset, length, last_piece); - if (ret <= 0) - goto out; + if (ret <= 0) { + if (do_datacrc) + msg->footer.data_crc = cpu_to_le32(crc); + return ret; + } out_msg_pos_next(con, page, length, (size_t) ret); } dout("%s %p msg %p done\n", __func__, con, msg); /* prepare and queue up footer, too */ - if (!do_datacrc) + if (do_datacrc) + msg->footer.data_crc = cpu_to_le32(crc); + else msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC; con_out_kvec_reset(con); prepare_write_message_footer(con); - ret = 1; -out: - return ret; + + return 1; /* must return > 0 to indicate success */ } /* @@ -2144,24 +2142,32 @@ static int read_partial_msg_data(struct ceph_connection *con) struct page *page; size_t page_offset; size_t length; + u32 crc = 0; int ret; BUG_ON(!msg); if (WARN_ON(!ceph_msg_has_data(msg))) return -EIO; + if (do_datacrc) + crc = con->in_data_crc; while (cursor->resid) { page = ceph_msg_data_next(&msg->data, &page_offset, &length, NULL); ret = ceph_tcp_recvpage(con->sock, page, page_offset, length); - if (ret <= 0) + if (ret <= 0) { + if (do_datacrc) + con->in_data_crc = crc; + return ret; + } if (do_datacrc) - con->in_data_crc = ceph_crc32c_page(con->in_data_crc, - page, page_offset, ret); + crc = ceph_crc32c_page(crc, page, page_offset, ret); in_msg_pos_next(con, length, ret); } + if (do_datacrc) + con->in_data_crc = crc; return 1; /* must return > 0 to indicate success */ } @@ -2257,7 +2263,7 @@ static int read_partial_message(struct ceph_connection *con) /* prepare for data payload, if any */ if (data_len) - prepare_message_data(con->in_msg, &con->in_msg_pos); + prepare_message_data(con->in_msg); } /* front */ -- cgit v0.10.2