[RFC PATCH 14/18] ceph: Remove ceph_pagelist

From: David Howells
Date: Fri Aug 04 2023 - 09:17:18 EST

Remove ceph_pagelist and its helpers.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/ceph/locks.c | 1 -
fs/ceph/mds_client.c | 1 -
fs/ceph/xattr.c | 1 -
include/linux/ceph/messenger.h | 8 --
include/linux/ceph/osd_client.h | 9 --
include/linux/ceph/pagelist.h | 72 --------------
net/ceph/Makefile | 2 +-
net/ceph/messenger.c | 110 --------------------
net/ceph/osd_client.c | 51 ----------
net/ceph/pagelist.c | 171 --------------------------------
10 files changed, 1 insertion(+), 425 deletions(-)
delete mode 100644 include/linux/ceph/pagelist.h
delete mode 100644 net/ceph/pagelist.c

diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index b3c018a8a92f..f80b09304fdc 100644
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -8,7 +8,6 @@
#include "super.h"
#include "mds_client.h"
#include <linux/filelock.h>
-#include <linux/ceph/pagelist.h>

static u64 lock_secret;
static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 9f5c4f47982e..e94877725824 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -21,7 +21,6 @@
#include <linux/ceph/ceph_features.h>
#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>
-#include <linux/ceph/pagelist.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index ca3ec5dd0382..d42779d10dc9 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1,6 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
-#include <linux/ceph/pagelist.h>

#include "super.h"
#include "mds_client.h"
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 0f4cc6e39da0..a2489e266bff 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -119,7 +119,6 @@ enum ceph_msg_data_type {
CEPH_MSG_DATA_NONE, /* message contains no data payload */
CEPH_MSG_DATA_DATABUF, /* data source/destination is a data buffer */
CEPH_MSG_DATA_PAGES, /* data source/destination is a page array */
- CEPH_MSG_DATA_PAGELIST, /* data source/destination is a pagelist */
CEPH_MSG_DATA_ITER, /* data source/destination is an iov_iter */
};

@@ -135,7 +134,6 @@ struct ceph_msg_data {
unsigned int offset; /* first page */
bool own_pages;
};
- struct ceph_pagelist *pagelist;
};
};

@@ -152,10 +150,6 @@ struct ceph_msg_data_cursor {
unsigned short page_index; /* index in array */
unsigned short page_count; /* pages in array */
};
- struct { /* pagelist */
- struct page *page; /* page from list */
- size_t offset; /* bytes from list */
- };
struct {
struct iov_iter iov_iter;
unsigned int lastlen;
@@ -510,8 +504,6 @@ extern bool ceph_con_keepalive_expired(struct ceph_connection *con,
void ceph_msg_data_add_databuf(struct ceph_msg *msg, struct ceph_databuf *dbuf);
void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
size_t length, size_t offset, bool own_pages);
-extern void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
- struct ceph_pagelist *pagelist);
void ceph_msg_data_add_iter(struct ceph_msg *msg,
struct iov_iter *iter);

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 82c1c325861d..83c3073c44bb 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -15,7 +15,6 @@
#include <linux/ceph/messenger.h>
#include <linux/ceph/msgpool.h>
#include <linux/ceph/auth.h>
-#include <linux/ceph/pagelist.h>
#include <linux/ceph/databuf.h>

struct ceph_msg;
@@ -105,7 +104,6 @@ enum ceph_osd_data_type {
CEPH_OSD_DATA_TYPE_NONE = 0,
CEPH_OSD_DATA_TYPE_DATABUF,
CEPH_OSD_DATA_TYPE_PAGES,
- CEPH_OSD_DATA_TYPE_PAGELIST,
CEPH_OSD_DATA_TYPE_ITER,
};

@@ -120,7 +118,6 @@ struct ceph_osd_data {
bool pages_from_pool;
bool own_pages;
};
- struct ceph_pagelist *pagelist;
struct iov_iter iter;
};
};
@@ -486,18 +483,12 @@ extern void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *,
void osd_req_op_raw_data_in_databuf(struct ceph_osd_request *osd_req,
unsigned int which,
struct ceph_databuf *databuf);
-extern void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *,
- unsigned int which,
- struct ceph_pagelist *pagelist);
void osd_req_op_extent_osd_iter(struct ceph_osd_request *osd_req,
unsigned int which, struct iov_iter *iter);

void osd_req_op_cls_request_databuf(struct ceph_osd_request *req,
unsigned int which,
struct ceph_databuf *dbuf);
-extern void osd_req_op_cls_request_data_pagelist(struct ceph_osd_request *,
- unsigned int which,
- struct ceph_pagelist *pagelist);
void osd_req_op_cls_response_databuf(struct ceph_osd_request *osd_req,
unsigned int which,
struct ceph_databuf *dbuf);
diff --git a/include/linux/ceph/pagelist.h b/include/linux/ceph/pagelist.h
deleted file mode 100644
index 5dead8486fd8..000000000000
--- a/include/linux/ceph/pagelist.h
+++ /dev/null
@@ -1,72 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __FS_CEPH_PAGELIST_H
-#define __FS_CEPH_PAGELIST_H
-
-#include <asm/byteorder.h>
-#include <linux/refcount.h>
-#include <linux/list.h>
-#include <linux/types.h>
-
-struct ceph_pagelist {
- struct list_head head;
- void *mapped_tail;
- size_t length;
- size_t room;
- struct list_head free_list;
- size_t num_pages_free;
- refcount_t refcnt;
-};
-
-struct ceph_pagelist_cursor {
- struct ceph_pagelist *pl; /* pagelist, for error checking */
- struct list_head *page_lru; /* page in list */
- size_t room; /* room remaining to reset to */
-};
-
-struct ceph_pagelist *ceph_pagelist_alloc(gfp_t gfp_flags);
-
-extern void ceph_pagelist_release(struct ceph_pagelist *pl);
-
-extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
-
-extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
-
-extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
-
-extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
- struct ceph_pagelist_cursor *c);
-
-extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
- struct ceph_pagelist_cursor *c);
-
-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, u32 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
diff --git a/net/ceph/Makefile b/net/ceph/Makefile
index 4b2e0b654e45..0c8787e2e733 100644
--- a/net/ceph/Makefile
+++ b/net/ceph/Makefile
@@ -4,7 +4,7 @@
#
obj-$(CONFIG_CEPH_LIB) += libceph.o

-libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \
+libceph-y := ceph_common.o messenger.o msgpool.o buffer.o \
mon_client.o decode.o \
cls_lock_client.o \
osd_client.o osdmap.o crush/crush.o crush/mapper.o crush/hash.o \
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 1ef3576c930d..5b28c27858b2 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -20,7 +20,6 @@
#include <linux/ceph/libceph.h>
#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>
-#include <linux/ceph/pagelist.h>
#include <linux/export.h>

/*
@@ -775,87 +774,6 @@ static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
return true;
}

-/*
- * For a pagelist, a piece is whatever remains to be consumed in the
- * first page in the list, or the front of the next page.
- */
-static void
-ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
- size_t length)
-{
- struct ceph_msg_data *data = cursor->data;
- struct ceph_pagelist *pagelist;
- struct page *page;
-
- BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
-
- pagelist = data->pagelist;
- BUG_ON(!pagelist);
-
- if (!length)
- return; /* pagelist can be assigned but empty */
-
- BUG_ON(list_empty(&pagelist->head));
- page = list_first_entry(&pagelist->head, struct page, lru);
-
- cursor->resid = min(length, pagelist->length);
- cursor->page = page;
- cursor->offset = 0;
-}
-
-static struct page *
-ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
- size_t *page_offset, size_t *length)
-{
- struct ceph_msg_data *data = cursor->data;
- struct ceph_pagelist *pagelist;
-
- BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
-
- pagelist = data->pagelist;
- BUG_ON(!pagelist);
-
- BUG_ON(!cursor->page);
- BUG_ON(cursor->offset + cursor->resid != pagelist->length);
-
- /* offset of first page in pagelist is always 0 */
- *page_offset = cursor->offset & ~PAGE_MASK;
- *length = min_t(size_t, cursor->resid, PAGE_SIZE - *page_offset);
- return cursor->page;
-}
-
-static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
- size_t bytes)
-{
- struct ceph_msg_data *data = cursor->data;
- struct ceph_pagelist *pagelist;
-
- BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
-
- pagelist = data->pagelist;
- BUG_ON(!pagelist);
-
- BUG_ON(cursor->offset + cursor->resid != pagelist->length);
- BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
-
- /* Advance the cursor offset */
-
- cursor->resid -= bytes;
- cursor->offset += bytes;
- /* offset of first page in pagelist is always 0 */
- if (!bytes || cursor->offset & ~PAGE_MASK)
- return false; /* more bytes to process in the current page */
-
- if (!cursor->resid)
- return false; /* no more data */
-
- /* Move on to the next page */
-
- BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
- cursor->page = list_next_entry(cursor->page, lru);
- return true;
-}
-
static void ceph_msg_data_iter_cursor_init(struct ceph_msg_data_cursor *cursor,
size_t length)
{
@@ -926,9 +844,6 @@ static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
size_t length = cursor->total_resid;

switch (cursor->data->type) {
- case CEPH_MSG_DATA_PAGELIST:
- ceph_msg_data_pagelist_cursor_init(cursor, length);
- break;
case CEPH_MSG_DATA_PAGES:
ceph_msg_data_pages_cursor_init(cursor, length);
break;
@@ -968,9 +883,6 @@ struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
struct page *page;

switch (cursor->data->type) {
- case CEPH_MSG_DATA_PAGELIST:
- page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
- break;
case CEPH_MSG_DATA_PAGES:
page = ceph_msg_data_pages_next(cursor, page_offset, length);
break;
@@ -1001,9 +913,6 @@ void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes)

BUG_ON(bytes > cursor->resid);
switch (cursor->data->type) {
- case CEPH_MSG_DATA_PAGELIST:
- new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
- break;
case CEPH_MSG_DATA_PAGES:
new_piece = ceph_msg_data_pages_advance(cursor, bytes);
break;
@@ -1740,8 +1649,6 @@ static void ceph_msg_data_destroy(struct ceph_msg_data *data)
} else if (data->type == CEPH_MSG_DATA_PAGES && data->own_pages) {
int num_pages = calc_pages_for(data->offset, data->length);
ceph_release_page_vector(data->pages, num_pages);
- } else if (data->type == CEPH_MSG_DATA_PAGELIST) {
- ceph_pagelist_release(data->pagelist);
}
}

@@ -1782,23 +1689,6 @@ void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
}
EXPORT_SYMBOL(ceph_msg_data_add_pages);

-void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
- struct ceph_pagelist *pagelist)
-{
- struct ceph_msg_data *data;
-
- BUG_ON(!pagelist);
- BUG_ON(!pagelist->length);
-
- data = ceph_msg_data_add(msg);
- data->type = CEPH_MSG_DATA_PAGELIST;
- refcount_inc(&pagelist->refcnt);
- data->pagelist = pagelist;
-
- msg->data_length += pagelist->length;
-}
-EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
-
void ceph_msg_data_add_iter(struct ceph_msg *msg,
struct iov_iter *iter)
{
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index c4486799f54b..8cbe06d2e16d 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -16,7 +16,6 @@
#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/auth.h>
-#include <linux/ceph/pagelist.h>
#include <linux/ceph/striper.h>

#define OSD_OPREPLY_FRONT_LEN 512
@@ -138,16 +137,6 @@ static void ceph_osd_data_pages_init(struct ceph_osd_data *osd_data,
osd_data->own_pages = own_pages;
}

-/*
- * Consumes a ref on @pagelist.
- */
-static void ceph_osd_data_pagelist_init(struct ceph_osd_data *osd_data,
- struct ceph_pagelist *pagelist)
-{
- osd_data->type = CEPH_OSD_DATA_TYPE_PAGELIST;
- osd_data->pagelist = pagelist;
-}
-
static void ceph_osd_iter_init(struct ceph_osd_data *osd_data,
struct iov_iter *iter)
{
@@ -229,16 +218,6 @@ void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *osd_req,
}
EXPORT_SYMBOL(osd_req_op_extent_osd_data_pages);

-void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *osd_req,
- unsigned int which, struct ceph_pagelist *pagelist)
-{
- struct ceph_osd_data *osd_data;
-
- osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
- ceph_osd_data_pagelist_init(osd_data, pagelist);
-}
-EXPORT_SYMBOL(osd_req_op_extent_osd_data_pagelist);
-
/**
* osd_req_op_extent_osd_iter - Set up an operation with an iterator buffer
* @osd_req: The request to set up
@@ -265,16 +244,6 @@ static void osd_req_op_cls_request_info_databuf(struct ceph_osd_request *osd_req
ceph_osd_databuf_init(osd_data, dbuf);
}

-static void osd_req_op_cls_request_info_pagelist(
- struct ceph_osd_request *osd_req,
- unsigned int which, struct ceph_pagelist *pagelist)
-{
- struct ceph_osd_data *osd_data;
-
- osd_data = osd_req_op_data(osd_req, which, cls, request_info);
- ceph_osd_data_pagelist_init(osd_data, pagelist);
-}
-
void osd_req_op_cls_request_databuf(struct ceph_osd_request *osd_req,
unsigned int which,
struct ceph_databuf *dbuf)
@@ -288,19 +257,6 @@ void osd_req_op_cls_request_databuf(struct ceph_osd_request *osd_req,
}
EXPORT_SYMBOL(osd_req_op_cls_request_databuf);

-void osd_req_op_cls_request_data_pagelist(
- struct ceph_osd_request *osd_req,
- unsigned int which, struct ceph_pagelist *pagelist)
-{
- struct ceph_osd_data *osd_data;
-
- osd_data = osd_req_op_data(osd_req, which, cls, request_data);
- ceph_osd_data_pagelist_init(osd_data, pagelist);
- osd_req->r_ops[which].cls.indata_len += pagelist->length;
- osd_req->r_ops[which].indata_len += pagelist->length;
-}
-EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
-
static void osd_req_op_cls_request_data_iter(
struct ceph_osd_request *osd_req,
unsigned int which, struct iov_iter *iter)
@@ -331,8 +287,6 @@ static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
return 0;
case CEPH_OSD_DATA_TYPE_PAGES:
return osd_data->length;
- case CEPH_OSD_DATA_TYPE_PAGELIST:
- return (u64)osd_data->pagelist->length;
case CEPH_OSD_DATA_TYPE_ITER:
return iov_iter_count(&osd_data->iter);
default:
@@ -349,8 +303,6 @@ static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
num_pages = calc_pages_for((u64)osd_data->offset,
(u64)osd_data->length);
ceph_release_page_vector(osd_data->pages, num_pages);
- } else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
- ceph_pagelist_release(osd_data->pagelist);
}
ceph_osd_data_init(osd_data);
}
@@ -934,9 +886,6 @@ static void ceph_osdc_msg_data_add(struct ceph_msg *msg,
if (length)
ceph_msg_data_add_pages(msg, osd_data->pages,
length, osd_data->offset, false);
- } else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
- BUG_ON(!length);
- ceph_msg_data_add_pagelist(msg, osd_data->pagelist);
} else if (osd_data->type == CEPH_OSD_DATA_TYPE_ITER) {
ceph_msg_data_add_iter(msg, &osd_data->iter);
} else {
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
deleted file mode 100644
index 74622b278d57..000000000000
--- a/net/ceph/pagelist.c
+++ /dev/null
@@ -1,171 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/module.h>
-#include <linux/gfp.h>
-#include <linux/slab.h>
-#include <linux/pagemap.h>
-#include <linux/highmem.h>
-#include <linux/ceph/pagelist.h>
-
-struct ceph_pagelist *ceph_pagelist_alloc(gfp_t gfp_flags)
-{
- struct ceph_pagelist *pl;
-
- pl = kmalloc(sizeof(*pl), gfp_flags);
- if (!pl)
- return NULL;
-
- INIT_LIST_HEAD(&pl->head);
- pl->mapped_tail = NULL;
- pl->length = 0;
- pl->room = 0;
- INIT_LIST_HEAD(&pl->free_list);
- pl->num_pages_free = 0;
- refcount_set(&pl->refcnt, 1);
-
- return pl;
-}
-EXPORT_SYMBOL(ceph_pagelist_alloc);
-
-static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl)
-{
- if (pl->mapped_tail) {
- struct page *page = list_entry(pl->head.prev, struct page, lru);
- kunmap(page);
- pl->mapped_tail = NULL;
- }
-}
-
-void ceph_pagelist_release(struct ceph_pagelist *pl)
-{
- if (!refcount_dec_and_test(&pl->refcnt))
- return;
- ceph_pagelist_unmap_tail(pl);
- while (!list_empty(&pl->head)) {
- struct page *page = list_first_entry(&pl->head, struct page,
- lru);
- list_del(&page->lru);
- __free_page(page);
- }
- ceph_pagelist_free_reserve(pl);
- kfree(pl);
-}
-EXPORT_SYMBOL(ceph_pagelist_release);
-
-static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
-{
- struct page *page;
-
- if (!pl->num_pages_free) {
- page = __page_cache_alloc(GFP_NOFS);
- } else {
- page = list_first_entry(&pl->free_list, struct page, lru);
- list_del(&page->lru);
- --pl->num_pages_free;
- }
- if (!page)
- return -ENOMEM;
- pl->room += PAGE_SIZE;
- ceph_pagelist_unmap_tail(pl);
- list_add_tail(&page->lru, &pl->head);
- pl->mapped_tail = kmap(page);
- return 0;
-}
-
-int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len)
-{
- while (pl->room < len) {
- size_t bit = pl->room;
- int ret;
-
- memcpy(pl->mapped_tail + (pl->length & ~PAGE_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_MASK), buf, len);
- pl->length += len;
- pl->room -= len;
- return 0;
-}
-EXPORT_SYMBOL(ceph_pagelist_append);
-
-/* Allocate enough pages for a pagelist to append the given amount
- * of data without allocating.
- * Returns: 0 on success, -ENOMEM on error.
- */
-int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space)
-{
- if (space <= pl->room)
- return 0;
- space -= pl->room;
- space = (space + PAGE_SIZE - 1) >> PAGE_SHIFT; /* conv to num pages */
-
- while (space > pl->num_pages_free) {
- struct page *page = __page_cache_alloc(GFP_NOFS);
- if (!page)
- return -ENOMEM;
- list_add_tail(&page->lru, &pl->free_list);
- ++pl->num_pages_free;
- }
- return 0;
-}
-EXPORT_SYMBOL(ceph_pagelist_reserve);
-
-/* Free any pages that have been preallocated. */
-int ceph_pagelist_free_reserve(struct ceph_pagelist *pl)
-{
- while (!list_empty(&pl->free_list)) {
- struct page *page = list_first_entry(&pl->free_list,
- struct page, lru);
- list_del(&page->lru);
- __free_page(page);
- --pl->num_pages_free;
- }
- BUG_ON(pl->num_pages_free);
- return 0;
-}
-EXPORT_SYMBOL(ceph_pagelist_free_reserve);
-
-/* Create a truncation point. */
-void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
- struct ceph_pagelist_cursor *c)
-{
- c->pl = pl;
- c->page_lru = pl->head.prev;
- c->room = pl->room;
-}
-EXPORT_SYMBOL(ceph_pagelist_set_cursor);
-
-/* Truncate a pagelist to the given point. Move extra pages to reserve.
- * This won't sleep.
- * Returns: 0 on success,
- * -EINVAL if the pagelist doesn't match the trunc point pagelist
- */
-int ceph_pagelist_truncate(struct ceph_pagelist *pl,
- struct ceph_pagelist_cursor *c)
-{
- struct page *page;
-
- if (pl != c->pl)
- return -EINVAL;
- ceph_pagelist_unmap_tail(pl);
- while (pl->head.prev != c->page_lru) {
- page = list_entry(pl->head.prev, struct page, lru);
- /* move from pagelist to reserve */
- list_move_tail(&page->lru, &pl->free_list);
- ++pl->num_pages_free;
- }
- pl->room = c->room;
- if (!list_empty(&pl->head)) {
- page = list_entry(pl->head.prev, struct page, lru);
- pl->mapped_tail = kmap(page);
- }
- return 0;
-}
-EXPORT_SYMBOL(ceph_pagelist_truncate);