From c5c6b19d4b8f5431fca05f28ae9e141045022149 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 9 Nov 2010 12:40:00 -0800 Subject: [PATCH] ceph: explicitly specify page alignment in network messages The alignment used for reading data into or out of pages used to be taken from the data_off field in the message header. This only worked as long as the page alignment matched the object offset, breaking direct io to non-page aligned offsets. Instead, explicitly specify the page alignment next to the page vector in the ceph_msg struct, and use that instead of the message header (which probably shouldn't be trusted). The alloc_msg callback is responsible for filling in this field properly when it sets up the page vector. Signed-off-by: Sage Weil --- include/linux/ceph/messenger.h | 1 + net/ceph/messenger.c | 10 +++++----- net/ceph/osd_client.c | 3 +++ 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 5956d62..a108b42 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -82,6 +82,7 @@ struct ceph_msg { struct ceph_buffer *middle; struct page **pages; /* data payload. NOT OWNER. */ unsigned nr_pages; /* size of page array */ + unsigned page_alignment; /* io offset in first page */ struct ceph_pagelist *pagelist; /* instead of pages */ struct list_head list_head; struct kref kref; diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index d379abf..1c7a2ec 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -540,8 +540,7 @@ static void prepare_write_message(struct ceph_connection *con) /* initialize page iterator */ con->out_msg_pos.page = 0; if (m->pages) - con->out_msg_pos.page_pos = - le16_to_cpu(m->hdr.data_off) & ~PAGE_MASK; + con->out_msg_pos.page_pos = m->page_alignment; else con->out_msg_pos.page_pos = 0; con->out_msg_pos.data_pos = 0; @@ -1491,7 +1490,7 @@ static int read_partial_message(struct ceph_connection *con) struct ceph_msg *m = con->in_msg; int ret; int to, left; - unsigned front_len, middle_len, data_len, data_off; + unsigned front_len, middle_len, data_len; int datacrc = con->msgr->nocrc; int skip; u64 seq; @@ -1527,7 +1526,6 @@ static int read_partial_message(struct ceph_connection *con) data_len = le32_to_cpu(con->in_hdr.data_len); if (data_len > CEPH_MSG_MAX_DATA_LEN) return -EIO; - data_off = le16_to_cpu(con->in_hdr.data_off); /* verify seq# */ seq = le64_to_cpu(con->in_hdr.seq); @@ -1575,7 +1573,7 @@ static int read_partial_message(struct ceph_connection *con) con->in_msg_pos.page = 0; if (m->pages) - con->in_msg_pos.page_pos = data_off & ~PAGE_MASK; + con->in_msg_pos.page_pos = m->page_alignment; else con->in_msg_pos.page_pos = 0; con->in_msg_pos.data_pos = 0; @@ -2300,6 +2298,7 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags) /* data */ m->nr_pages = 0; + m->page_alignment = 0; m->pages = NULL; m->pagelist = NULL; m->bio = NULL; @@ -2369,6 +2368,7 @@ static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con, type, front_len); return NULL; } + msg->page_alignment = le16_to_cpu(hdr->data_off); } memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr)); diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 6c09623..3e20a12 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -391,6 +391,8 @@ void ceph_osdc_build_request(struct ceph_osd_request *req, req->r_request->hdr.data_len = cpu_to_le32(data_len); } + req->r_request->page_alignment = req->r_page_alignment; + BUG_ON(p > msg->front.iov_base + msg->front.iov_len); msg_size = p - msg->front.iov_base; msg->front.iov_len = msg_size; @@ -1657,6 +1659,7 @@ static struct ceph_msg *get_reply(struct ceph_connection *con, } m->pages = req->r_pages; m->nr_pages = req->r_num_pages; + m->page_alignment = req->r_page_alignment; #ifdef CONFIG_BLOCK m->bio = req->r_bio; #endif -- 2.7.4