libceph: isolate message page field manipulation
Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure. Use this new function in the osd client and mds
client.
Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that). At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once. (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)
Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.
This partially resolves:
http://tracker.ceph.com/issues/4263
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index ecfb738..90198a4 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1721,8 +1721,8 @@
msg->front.iov_len = p - msg->front.iov_base;
msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
- msg->pages = req->r_pages;
- msg->page_count = req->r_num_pages;
+ ceph_msg_data_set_pages(msg, req->r_pages, req->r_num_pages, 0);
+
msg->hdr.data_len = cpu_to_le32(req->r_data_len);
msg->hdr.data_off = cpu_to_le16(0);
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 6c11874..aa463b9 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -74,21 +74,22 @@
struct ceph_msg_footer footer; /* footer */
struct kvec front; /* unaligned blobs of message */
struct ceph_buffer *middle;
- struct page **pages; /* data payload. NOT OWNER. */
- unsigned page_count; /* size of page array */
- unsigned page_alignment; /* io offset in first page */
+
+ struct page **pages; /* data payload. NOT OWNER. */
+ unsigned int page_alignment; /* io offset in first page */
+ unsigned int page_count; /* # pages in array or list */
struct ceph_pagelist *pagelist; /* instead of pages */
-
- struct ceph_connection *con;
- struct list_head list_head;
-
- struct kref kref;
#ifdef CONFIG_BLOCK
+ unsigned int bio_seg; /* current bio segment */
struct bio *bio; /* instead of pages/pagelist */
struct bio *bio_iter; /* bio iterator */
- unsigned int bio_seg; /* current bio segment */
#endif /* CONFIG_BLOCK */
struct ceph_pagelist *trail; /* the trailing part of the data */
+
+ struct ceph_connection *con;
+ struct list_head list_head; /* links for connection lists */
+
+ struct kref kref;
bool front_is_vmalloc;
bool more_to_follow;
bool needs_out_seq;
@@ -218,6 +219,9 @@
extern void ceph_con_keepalive(struct ceph_connection *con);
+extern void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
+ unsigned int page_count, size_t alignment);
+
extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
bool can_fail);
extern void ceph_msg_kfree(struct ceph_msg *m);
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index ce1669f..cec39cb 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2689,6 +2689,17 @@
}
EXPORT_SYMBOL(ceph_con_keepalive);
+void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
+ unsigned int page_count, size_t alignment)
+{
+ /* BUG_ON(msg->pages); */
+ /* BUG_ON(msg->page_count); */
+
+ msg->pages = pages;
+ msg->page_count = page_count;
+ msg->page_alignment = alignment & ~PAGE_MASK;
+}
+EXPORT_SYMBOL(ceph_msg_data_set_pages);
/*
* construct a new message with given type, size
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 202af14..a09d571 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1760,11 +1760,10 @@
if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
unsigned int page_count;
- req->r_request->pages = osd_data->pages;
page_count = calc_pages_for((u64)osd_data->alignment,
(u64)osd_data->length);
- req->r_request->page_count = page_count;
- req->r_request->page_alignment = osd_data->alignment;
+ ceph_msg_data_set_pages(req->r_request, osd_data->pages,
+ page_count, osd_data->alignment);
#ifdef CONFIG_BLOCK
} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
req->r_request->bio = osd_data->bio;
@@ -2135,9 +2134,8 @@
}
page_count = calc_pages_for((u64)osd_data->alignment,
(u64)osd_data->length);
- m->pages = osd_data->pages;
- m->page_count = page_count;
- m->page_alignment = osd_data->alignment;
+ ceph_msg_data_set_pages(m, osd_data->pages,
+ osd_data->num_pages, osd_data->alignment);
#ifdef CONFIG_BLOCK
} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
m->bio = osd_data->bio;
