Commit 58bb3b37 authored by Sage Weil's avatar Sage Weil
Browse files

ceph: support ceph_pagelist for message payload 



The ceph_pagelist is a simple list of whole pages, strung together via
their lru list_head.  It facilitates encoding to a "buffer" of unknown
size.  Allow its use in place of the ceph_msg page vector.

This will be used to fix the huge buffer preallocation woes of MDS
reconnection.

Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent 04a419f9

fs/ceph/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ obj-$(CONFIG_CEPH_FS) += ceph.o 


ceph-objs := super.o inode.o dir.o file.o addr.o ioctl.o \

	export.o caps.o snap.o xattr.o \

	messenger.o msgpool.o buffer.o \

	messenger.o msgpool.o buffer.o pagelist.o \

	mds_client.o mdsmap.o \

	mon_client.o \

	osd_client.o osdmap.o crush/crush.o crush/mapper.o crush/hash.o \

fs/ceph/messenger.c

+20 −4
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include "super.h"

#include "messenger.h"

#include "decode.h"

#include "pagelist.h"



/*

 * Ceph uses the messenger to exchange ceph_msg messages with other
@@ -728,6 +729,11 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
			page = msg->pages[con->out_msg_pos.page];

			if (crc)

				kaddr = kmap(page);

		} else if (msg->pagelist) {

			page = list_first_entry(&msg->pagelist->head,

						struct page, lru);

			if (crc)

				kaddr = kmap(page);

		} else {

			page = con->msgr->zero_page;

			if (crc)
@@ -750,7 +756,7 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
				      MSG_DONTWAIT | MSG_NOSIGNAL |

				      MSG_MORE);



		if (crc && msg->pages)

		if (crc && (msg->pages || msg->pagelist))

			kunmap(page);



		if (ret <= 0)
@@ -762,6 +768,9 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
			con->out_msg_pos.page_pos = 0;

			con->out_msg_pos.page++;

			con->out_msg_pos.did_page_crc = 0;

			if (msg->pagelist)

				list_move_tail(&page->lru,

					       &msg->pagelist->head);

		}

	}
@@ -1051,13 +1060,13 @@ static int process_banner(struct ceph_connection *con) 
				       &con->actual_peer_addr) &&

	    !(addr_is_blank(&con->actual_peer_addr.in_addr) &&

	      con->actual_peer_addr.nonce == con->peer_addr.nonce)) {

		pr_err("wrong peer, want %s/%d, "

		       "got %s/%d, wtf\n",

		pr_warning("wrong peer, want %s/%d, "

		       "got %s/%d\n",

		       pr_addr(&con->peer_addr.in_addr),

		       con->peer_addr.nonce,

		       pr_addr(&con->actual_peer_addr.in_addr),

		       con->actual_peer_addr.nonce);

		con->error_msg = "protocol error, wrong peer";

		con->error_msg = "wrong peer at address";

		return -1;

	}
@@ -2096,6 +2105,7 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, 
	/* data */

	m->nr_pages = calc_pages_for(page_off, page_len);

	m->pages = pages;

	m->pagelist = NULL;



	dout("ceph_msg_new %p page %d~%d -> %d\n", m, page_off, page_len,

	     m->nr_pages);
@@ -2181,6 +2191,12 @@ void ceph_msg_last_put(struct kref *kref) 
	m->nr_pages = 0;

	m->pages = NULL;



	if (m->pagelist) {

		ceph_pagelist_release(m->pagelist);

		kfree(m->pagelist);

		m->pagelist = NULL;

	}



	if (m->pool)

		ceph_msgpool_put(m->pool, m);

	else

fs/ceph/messenger.h

+1 −0
Original line number Diff line number Diff line
@@ -85,6 +85,7 @@ struct ceph_msg { 
	struct ceph_buffer *middle;

	struct page **pages;            /* data payload.  NOT OWNER. */

	unsigned nr_pages;              /* size of page array */

	struct ceph_pagelist *pagelist; /* instead of pages */

	struct list_head list_head;

	struct kref kref;

	bool front_is_vmalloc;

fs/ceph/pagelist.c

0 → 100644
+54 −0
Original line number Diff line number Diff line 


#include <linux/pagemap.h>

#include <linux/highmem.h>



#include "pagelist.h"



int ceph_pagelist_release(struct ceph_pagelist *pl)

{

	if (pl->mapped_tail)

		kunmap(pl->mapped_tail);

	while (!list_empty(&pl->head)) {

		struct page *page = list_first_entry(&pl->head, struct page,

						     lru);

		list_del(&page->lru);

		__free_page(page);

	}

	return 0;

}



static int ceph_pagelist_addpage(struct ceph_pagelist *pl)

{

	struct page *page = alloc_page(GFP_NOFS);

	if (!page)

		return -ENOMEM;

	pl->room += PAGE_SIZE;

	list_add_tail(&page->lru, &pl->head);

	if (pl->mapped_tail)

		kunmap(pl->mapped_tail);

	pl->mapped_tail = kmap(page);

	return 0;

}



int ceph_pagelist_append(struct ceph_pagelist *pl, void *buf, size_t len)

{

	while (pl->room < len) {

		size_t bit = pl->room;

		int ret;



		memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK),

		       buf, bit);

		pl->length += bit;

		pl->room -= bit;

		buf += bit;

		len -= bit;

		ret = ceph_pagelist_addpage(pl);

		if (ret)

			return ret;

	}



	memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len);

	pl->length += len;

	pl->room -= len;

	return 0;

}

fs/ceph/pagelist.h

0 → 100644
+54 −0
Original line number Diff line number Diff line 
#ifndef __FS_CEPH_PAGELIST_H

#define __FS_CEPH_PAGELIST_H



#include <linux/list.h>



struct ceph_pagelist {

	struct list_head head;

	void *mapped_tail;

	size_t length;

	size_t room;

};



static inline void ceph_pagelist_init(struct ceph_pagelist *pl)

{

	INIT_LIST_HEAD(&pl->head);

	pl->mapped_tail = NULL;

	pl->length = 0;

	pl->room = 0;

}

extern int ceph_pagelist_release(struct ceph_pagelist *pl);



extern int ceph_pagelist_append(struct ceph_pagelist *pl, void *d, size_t l);



static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)

{

	__le64 ev = cpu_to_le64(v);

	return ceph_pagelist_append(pl, &ev, sizeof(ev));

}

static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)

{

	__le32 ev = cpu_to_le32(v);

	return ceph_pagelist_append(pl, &ev, sizeof(ev));

}

static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)

{

	__le16 ev = cpu_to_le16(v);

	return ceph_pagelist_append(pl, &ev, sizeof(ev));

}

static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)

{

	return ceph_pagelist_append(pl, &v, 1);

}

static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,

					      char *s, size_t len)

{

	int ret = ceph_pagelist_encode_32(pl, len);

	if (ret)

		return ret;

	if (len)

		return ceph_pagelist_append(pl, s, len);

	return 0;

}



#endif