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/*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see
* http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
* GPL HEADER END
*/
/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2012, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Lustre is a trademark of Sun Microsystems, Inc.
*
* lustre/lustre/llite/rw26.c
*
* Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <asm/uaccess.h>
#include <linux/migrate.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/mpage.h>
#include <linux/writeback.h>
#include <linux/pagemap.h>
#define DEBUG_SUBSYSTEM S_LLITE
#include <lustre_lite.h>
#include "llite_internal.h"
#include <linux/lustre_compat25.h>
/**
* Implements Linux VM address_space::invalidatepage() method. This method is
* called when the page is truncate from a file, either as a result of
* explicit truncate, or when inode is removed from memory (as a result of
* final iput(), umount, or memory pressure induced icache shrinking).
*
* [0, offset] bytes of the page remain valid (this is for a case of not-page
* aligned truncate). Lustre leaves partially truncated page in the cache,
* relying on struct inode::i_size to limit further accesses.
*/
static void ll_invalidatepage(struct page *vmpage, unsigned int offset,
unsigned int length)
{
struct inode *inode;
struct lu_env *env;
struct cl_page *page;
struct cl_object *obj;
int refcheck;
LASSERT(PageLocked(vmpage));
LASSERT(!PageWriteback(vmpage));
/*
* It is safe to not check anything in invalidatepage/releasepage
* below because they are run with page locked and all our io is
* happening with locked page too
*/
if (offset == 0 && length == PAGE_CACHE_SIZE) {
env = cl_env_get(&refcheck);
if (!IS_ERR(env)) {
inode = vmpage->mapping->host;
obj = ll_i2info(inode)->lli_clob;
if (obj != NULL) {
page = cl_vmpage_page(vmpage, obj);
if (page != NULL) {
lu_ref_add(&page->cp_reference,
"delete", vmpage);
cl_page_delete(env, page);
lu_ref_del(&page->cp_reference,
"delete", vmpage);
cl_page_put(env, page);
}
} else
LASSERT(vmpage->private == 0);
cl_env_put(env, &refcheck);
}
}
}
#ifdef HAVE_RELEASEPAGE_WITH_INT
#define RELEASEPAGE_ARG_TYPE int
#else
#define RELEASEPAGE_ARG_TYPE gfp_t
#endif
static int ll_releasepage(struct page *vmpage, RELEASEPAGE_ARG_TYPE gfp_mask)
{
struct cl_env_nest nest;
struct lu_env *env;
struct cl_object *obj;
struct cl_page *page;
struct address_space *mapping;
int result;
LASSERT(PageLocked(vmpage));
if (PageWriteback(vmpage) || PageDirty(vmpage))
return 0;
mapping = vmpage->mapping;
if (mapping == NULL)
return 1;
obj = ll_i2info(mapping->host)->lli_clob;
if (obj == NULL)
return 1;
/* 1 for page allocator, 1 for cl_page and 1 for page cache */
if (page_count(vmpage) > 3)
return 0;
/* TODO: determine what gfp should be used by @gfp_mask. */
env = cl_env_nested_get(&nest);
if (IS_ERR(env))
/* If we can't allocate an env we won't call cl_page_put()
* later on which further means it's impossible to drop
* page refcount by cl_page, so ask kernel to not free
* this page. */
return 0;
page = cl_vmpage_page(vmpage, obj);
result = page == NULL;
if (page != NULL) {
if (!cl_page_in_use(page)) {
result = 1;
cl_page_delete(env, page);
}
cl_page_put(env, page);
}
cl_env_nested_put(&nest, env);
return result;
}
static int ll_set_page_dirty(struct page *vmpage)
{
#if 0
struct cl_page *page = vvp_vmpage_page_transient(vmpage);
struct vvp_object *obj = cl_inode2vvp(vmpage->mapping->host);
struct vvp_page *cpg;
/*
* XXX should page method be called here?
*/
LASSERT(&obj->co_cl == page->cp_obj);
cpg = cl2vvp_page(cl_page_at(page, &vvp_device_type));
/*
* XXX cannot do much here, because page is possibly not locked:
* sys_munmap()->...
* ->unmap_page_range()->zap_pte_range()->set_page_dirty().
*/
vvp_write_pending(obj, cpg);
#endif
return __set_page_dirty_nobuffers(vmpage);
}
#define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
static inline int ll_get_user_pages(int rw, unsigned long user_addr,
size_t size, struct page ***pages,
int *max_pages)
{
int result = -ENOMEM;
/* set an arbitrary limit to prevent arithmetic overflow */
if (size > MAX_DIRECTIO_SIZE) {
*pages = NULL;
return -EFBIG;
}
*max_pages = (user_addr + size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
*max_pages -= user_addr >> PAGE_CACHE_SHIFT;
OBD_ALLOC_LARGE(*pages, *max_pages * sizeof(**pages));
if (*pages) {
result = get_user_pages_fast(user_addr, *max_pages,
(rw == READ), *pages);
if (unlikely(result <= 0))
OBD_FREE_LARGE(*pages, *max_pages * sizeof(**pages));
}
return result;
}
/* ll_free_user_pages - tear down page struct array
* @pages: array of page struct pointers underlying target buffer */
static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
{
int i;
for (i = 0; i < npages; i++) {
if (pages[i] == NULL)
break;
if (do_dirty)
set_page_dirty_lock(pages[i]);
page_cache_release(pages[i]);
}
OBD_FREE_LARGE(pages, npages * sizeof(*pages));
}
ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
int rw, struct inode *inode,
struct ll_dio_pages *pv)
{
struct cl_page *clp;
struct cl_2queue *queue;
struct cl_object *obj = io->ci_obj;
int i;
ssize_t rc = 0;
loff_t file_offset = pv->ldp_start_offset;
long size = pv->ldp_size;
int page_count = pv->ldp_nr;
struct page **pages = pv->ldp_pages;
long page_size = cl_page_size(obj);
bool do_io;
int io_pages = 0;
queue = &io->ci_queue;
cl_2queue_init(queue);
for (i = 0; i < page_count; i++) {
if (pv->ldp_offsets)
file_offset = pv->ldp_offsets[i];
LASSERT(!(file_offset & (page_size - 1)));
clp = cl_page_find(env, obj, cl_index(obj, file_offset),
pv->ldp_pages[i], CPT_TRANSIENT);
if (IS_ERR(clp)) {
rc = PTR_ERR(clp);
break;
}
rc = cl_page_own(env, io, clp);
if (rc) {
LASSERT(clp->cp_state == CPS_FREEING);
cl_page_put(env, clp);
break;
}
do_io = true;
/* check the page type: if the page is a host page, then do
* write directly */
if (clp->cp_type == CPT_CACHEABLE) {
struct page *vmpage = cl_page_vmpage(env, clp);
struct page *src_page;
struct page *dst_page;
void *src;
void *dst;
src_page = (rw == WRITE) ? pages[i] : vmpage;
dst_page = (rw == WRITE) ? vmpage : pages[i];
src = kmap_atomic(src_page);
dst = kmap_atomic(dst_page);
memcpy(dst, src, min(page_size, size));
kunmap_atomic(dst);
kunmap_atomic(src);
/* make sure page will be added to the transfer by
* cl_io_submit()->...->vvp_page_prep_write(). */
if (rw == WRITE)
set_page_dirty(vmpage);
if (rw == READ) {
/* do not issue the page for read, since it
* may reread a ra page which has NOT uptodate
* bit set. */
cl_page_disown(env, io, clp);
do_io = false;
}
}
if (likely(do_io)) {
cl_2queue_add(queue, clp);
/*
* Set page clip to tell transfer formation engine
* that page has to be sent even if it is beyond KMS.
*/
cl_page_clip(env, clp, 0, min(size, page_size));
++io_pages;
}
/* drop the reference count for cl_page_find */
cl_page_put(env, clp);
size -= page_size;
file_offset += page_size;
}
if (rc == 0 && io_pages) {
rc = cl_io_submit_sync(env, io,
rw == READ ? CRT_READ : CRT_WRITE,
queue, 0);
}
if (rc == 0)
rc = pv->ldp_size;
cl_2queue_discard(env, io, queue);
cl_2queue_disown(env, io, queue);
cl_2queue_fini(env, queue);
return rc;
}
EXPORT_SYMBOL(ll_direct_rw_pages);
static ssize_t ll_direct_IO_26_seg(const struct lu_env *env, struct cl_io *io,
int rw, struct inode *inode,
struct address_space *mapping,
size_t size, loff_t file_offset,
struct page **pages, int page_count)
{
struct ll_dio_pages pvec = { .ldp_pages = pages,
.ldp_nr = page_count,
.ldp_size = size,
.ldp_offsets = NULL,
.ldp_start_offset = file_offset
};
return ll_direct_rw_pages(env, io, rw, inode, &pvec);
}
#ifdef KMALLOC_MAX_SIZE
#define MAX_MALLOC KMALLOC_MAX_SIZE
#else
#define MAX_MALLOC (128 * 1024)
#endif
/* This is the maximum size of a single O_DIRECT request, based on the
* kmalloc limit. We need to fit all of the brw_page structs, each one
* representing PAGE_SIZE worth of user data, into a single buffer, and
* then truncate this to be a full-sized RPC. For 4kB PAGE_SIZE this is
* up to 22MB for 128kB kmalloc and up to 682MB for 4MB kmalloc. */
#define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_CACHE_SIZE) & \
~(DT_MAX_BRW_SIZE - 1))
static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
struct iov_iter *iter, loff_t file_offset)
{
struct lu_env *env;
struct cl_io *io;
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct ccc_object *obj = cl_inode2ccc(inode);
long count = iov_iter_count(iter);
long tot_bytes = 0, result = 0;
struct ll_inode_info *lli = ll_i2info(inode);
unsigned long seg = 0;
long size = MAX_DIO_SIZE;
int refcheck;
if (!lli->lli_has_smd)
return -EBADF;
/* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
return -EINVAL;
CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size=%lu (max %lu), "
"offset=%lld=%llx, pages %lu (max %lu)\n",
inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
file_offset, file_offset, count >> PAGE_CACHE_SHIFT,
MAX_DIO_SIZE >> PAGE_CACHE_SHIFT);
/* Check that all user buffers are aligned as well */
for (seg = 0; seg < iter->nr_segs; seg++) {
if (((unsigned long)iter->iov[seg].iov_base & ~CFS_PAGE_MASK) ||
(iter->iov[seg].iov_len & ~CFS_PAGE_MASK))
return -EINVAL;
}
env = cl_env_get(&refcheck);
LASSERT(!IS_ERR(env));
io = ccc_env_io(env)->cui_cl.cis_io;
LASSERT(io != NULL);
/* 0. Need locking between buffered and direct access. and race with
* size changing by concurrent truncates and writes.
* 1. Need inode mutex to operate transient pages.
*/
if (rw == READ)
mutex_lock(&inode->i_mutex);
LASSERT(obj->cob_transient_pages == 0);
for (seg = 0; seg < iter->nr_segs; seg++) {
long iov_left = iter->iov[seg].iov_len;
unsigned long user_addr = (unsigned long)iter->iov[seg].iov_base;
if (rw == READ) {
if (file_offset >= i_size_read(inode))
break;
if (file_offset + iov_left > i_size_read(inode))
iov_left = i_size_read(inode) - file_offset;
}
while (iov_left > 0) {
struct page **pages;
int page_count, max_pages = 0;
long bytes;
bytes = min(size, iov_left);
page_count = ll_get_user_pages(rw, user_addr, bytes,
&pages, &max_pages);
if (likely(page_count > 0)) {
if (unlikely(page_count < max_pages))
bytes = page_count << PAGE_CACHE_SHIFT;
result = ll_direct_IO_26_seg(env, io, rw, inode,
file->f_mapping,
bytes, file_offset,
pages, page_count);
ll_free_user_pages(pages, max_pages, rw==READ);
} else if (page_count == 0) {
GOTO(out, result = -EFAULT);
} else {
result = page_count;
}
if (unlikely(result <= 0)) {
/* If we can't allocate a large enough buffer
* for the request, shrink it to a smaller
* PAGE_SIZE multiple and try again.
* We should always be able to kmalloc for a
* page worth of page pointers = 4MB on i386. */
if (result == -ENOMEM &&
size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
PAGE_CACHE_SIZE) {
size = ((((size / 2) - 1) |
~CFS_PAGE_MASK) + 1) &
CFS_PAGE_MASK;
CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
size);
continue;
}
GOTO(out, result);
}
tot_bytes += result;
file_offset += result;
iov_left -= result;
user_addr += result;
}
}
out:
LASSERT(obj->cob_transient_pages == 0);
if (rw == READ)
mutex_unlock(&inode->i_mutex);
if (tot_bytes > 0) {
if (rw == WRITE) {
struct lov_stripe_md *lsm;
lsm = ccc_inode_lsm_get(inode);
LASSERT(lsm != NULL);
lov_stripe_lock(lsm);
obd_adjust_kms(ll_i2dtexp(inode), lsm, file_offset, 0);
lov_stripe_unlock(lsm);
ccc_inode_lsm_put(inode, lsm);
}
}
cl_env_put(env, &refcheck);
return tot_bytes ? : result;
}
static int ll_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
struct page *page;
int rc;
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
*pagep = page;
rc = ll_prepare_write(file, page, from, from + len);
if (rc) {
unlock_page(page);
page_cache_release(page);
}
return rc;
}
static int ll_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
int rc;
rc = ll_commit_write(file, page, from, from + copied);
unlock_page(page);
page_cache_release(page);
return rc ?: copied;
}
#ifdef CONFIG_MIGRATION
int ll_migratepage(struct address_space *mapping,
struct page *newpage, struct page *page
, enum migrate_mode mode
)
{
/* Always fail page migration until we have a proper implementation */
return -EIO;
}
#endif
#ifndef MS_HAS_NEW_AOPS
struct address_space_operations ll_aops = {
.readpage = ll_readpage,
// .readpages = ll_readpages,
.direct_IO = ll_direct_IO_26,
.writepage = ll_writepage,
.writepages = ll_writepages,
.set_page_dirty = ll_set_page_dirty,
.write_begin = ll_write_begin,
.write_end = ll_write_end,
.invalidatepage = ll_invalidatepage,
.releasepage = (void *)ll_releasepage,
#ifdef CONFIG_MIGRATION
.migratepage = ll_migratepage,
#endif
.bmap = NULL
};
#else
struct address_space_operations_ext ll_aops = {
.orig_aops.readpage = ll_readpage,
// .orig_aops.readpages = ll_readpages,
.orig_aops.direct_IO = ll_direct_IO_26,
.orig_aops.writepage = ll_writepage,
.orig_aops.writepages = ll_writepages,
.orig_aops.set_page_dirty = ll_set_page_dirty,
.orig_aops.prepare_write = ll_prepare_write,
.orig_aops.commit_write = ll_commit_write,
.orig_aops.invalidatepage = ll_invalidatepage,
.orig_aops.releasepage = ll_releasepage,
#ifdef CONFIG_MIGRATION
.orig_aops.migratepage = ll_migratepage,
#endif
.orig_aops.bmap = NULL,
.write_begin = ll_write_begin,
.write_end = ll_write_end
};
#endif
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