1286 lines
37 KiB
C
1286 lines
37 KiB
C
/*
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* GPL HEADER START
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*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 only,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License version 2 for more details (a copy is included
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* in the LICENSE file that accompanied this code).
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; If not, see
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* http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
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*
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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* CA 95054 USA or visit www.sun.com if you need additional information or
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* have any questions.
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*
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* GPL HEADER END
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*/
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/*
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* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
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* Use is subject to license terms.
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*
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* Copyright (c) 2011, 2012, Intel Corporation.
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*/
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/*
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* This file is part of Lustre, http://www.lustre.org/
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* Lustre is a trademark of Sun Microsystems, Inc.
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*
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* lustre/llite/rw.c
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*
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* Lustre Lite I/O page cache routines shared by different kernel revs
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*/
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/unistd.h>
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#include <linux/writeback.h>
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#include <asm/uaccess.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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/* current_is_kswapd() */
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#include <linux/swap.h>
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#define DEBUG_SUBSYSTEM S_LLITE
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#include "../include/lustre_lite.h"
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#include "../include/obd_cksum.h"
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#include "llite_internal.h"
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#include "../include/linux/lustre_compat25.h"
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/**
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* Finalizes cl-data before exiting typical address_space operation. Dual to
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* ll_cl_init().
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*/
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static void ll_cl_fini(struct ll_cl_context *lcc)
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{
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struct lu_env *env = lcc->lcc_env;
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struct cl_io *io = lcc->lcc_io;
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struct cl_page *page = lcc->lcc_page;
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LASSERT(lcc->lcc_cookie == current);
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LASSERT(env != NULL);
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if (page != NULL) {
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lu_ref_del(&page->cp_reference, "cl_io", io);
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cl_page_put(env, page);
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}
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cl_env_put(env, &lcc->lcc_refcheck);
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}
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/**
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* Initializes common cl-data at the typical address_space operation entry
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* point.
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*/
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static struct ll_cl_context *ll_cl_init(struct file *file,
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struct page *vmpage, int create)
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{
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struct ll_cl_context *lcc;
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struct lu_env *env;
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struct cl_io *io;
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struct cl_object *clob;
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struct ccc_io *cio;
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int refcheck;
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int result = 0;
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clob = ll_i2info(vmpage->mapping->host)->lli_clob;
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LASSERT(clob != NULL);
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env = cl_env_get(&refcheck);
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if (IS_ERR(env))
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return ERR_CAST(env);
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lcc = &vvp_env_info(env)->vti_io_ctx;
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memset(lcc, 0, sizeof(*lcc));
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lcc->lcc_env = env;
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lcc->lcc_refcheck = refcheck;
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lcc->lcc_cookie = current;
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cio = ccc_env_io(env);
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io = cio->cui_cl.cis_io;
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if (io == NULL && create) {
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struct inode *inode = vmpage->mapping->host;
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loff_t pos;
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if (mutex_trylock(&inode->i_mutex)) {
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mutex_unlock(&(inode)->i_mutex);
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/* this is too bad. Someone is trying to write the
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* page w/o holding inode mutex. This means we can
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* add dirty pages into cache during truncate */
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CERROR("Proc %s is dirting page w/o inode lock, this"
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"will break truncate.\n", current->comm);
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dump_stack();
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LBUG();
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return ERR_PTR(-EIO);
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}
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/*
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* Loop-back driver calls ->prepare_write().
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* methods directly, bypassing file system ->write() operation,
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* so cl_io has to be created here.
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*/
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io = ccc_env_thread_io(env);
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ll_io_init(io, file, 1);
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/* No lock at all for this kind of IO - we can't do it because
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* we have held page lock, it would cause deadlock.
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* XXX: This causes poor performance to loop device - One page
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* per RPC.
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* In order to get better performance, users should use
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* lloop driver instead.
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*/
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io->ci_lockreq = CILR_NEVER;
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pos = (vmpage->index << PAGE_CACHE_SHIFT);
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/* Create a temp IO to serve write. */
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result = cl_io_rw_init(env, io, CIT_WRITE, pos, PAGE_CACHE_SIZE);
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if (result == 0) {
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cio->cui_fd = LUSTRE_FPRIVATE(file);
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cio->cui_iter = NULL;
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result = cl_io_iter_init(env, io);
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if (result == 0) {
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result = cl_io_lock(env, io);
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if (result == 0)
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result = cl_io_start(env, io);
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}
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} else
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result = io->ci_result;
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}
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lcc->lcc_io = io;
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if (io == NULL)
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result = -EIO;
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if (result == 0) {
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struct cl_page *page;
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LASSERT(io != NULL);
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LASSERT(io->ci_state == CIS_IO_GOING);
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LASSERT(cio->cui_fd == LUSTRE_FPRIVATE(file));
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page = cl_page_find(env, clob, vmpage->index, vmpage,
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CPT_CACHEABLE);
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if (!IS_ERR(page)) {
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lcc->lcc_page = page;
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lu_ref_add(&page->cp_reference, "cl_io", io);
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result = 0;
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} else
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result = PTR_ERR(page);
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}
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if (result) {
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ll_cl_fini(lcc);
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lcc = ERR_PTR(result);
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}
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CDEBUG(D_VFSTRACE, "%lu@"DFID" -> %d %p %p\n",
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vmpage->index, PFID(lu_object_fid(&clob->co_lu)), result,
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env, io);
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return lcc;
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}
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static struct ll_cl_context *ll_cl_get(void)
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{
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struct ll_cl_context *lcc;
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struct lu_env *env;
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int refcheck;
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env = cl_env_get(&refcheck);
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LASSERT(!IS_ERR(env));
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lcc = &vvp_env_info(env)->vti_io_ctx;
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LASSERT(env == lcc->lcc_env);
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LASSERT(current == lcc->lcc_cookie);
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cl_env_put(env, &refcheck);
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/* env has got in ll_cl_init, so it is still usable. */
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return lcc;
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}
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/**
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* ->prepare_write() address space operation called by generic_file_write()
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* for every page during write.
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*/
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int ll_prepare_write(struct file *file, struct page *vmpage, unsigned from,
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unsigned to)
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{
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struct ll_cl_context *lcc;
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int result;
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lcc = ll_cl_init(file, vmpage, 1);
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if (!IS_ERR(lcc)) {
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struct lu_env *env = lcc->lcc_env;
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struct cl_io *io = lcc->lcc_io;
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struct cl_page *page = lcc->lcc_page;
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cl_page_assume(env, io, page);
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result = cl_io_prepare_write(env, io, page, from, to);
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if (result == 0) {
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/*
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* Add a reference, so that page is not evicted from
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* the cache until ->commit_write() is called.
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*/
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cl_page_get(page);
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lu_ref_add(&page->cp_reference, "prepare_write",
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current);
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} else {
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cl_page_unassume(env, io, page);
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ll_cl_fini(lcc);
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}
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/* returning 0 in prepare assumes commit must be called
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* afterwards */
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} else {
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result = PTR_ERR(lcc);
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}
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return result;
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}
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int ll_commit_write(struct file *file, struct page *vmpage, unsigned from,
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unsigned to)
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{
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struct ll_cl_context *lcc;
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struct lu_env *env;
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struct cl_io *io;
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struct cl_page *page;
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int result = 0;
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lcc = ll_cl_get();
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env = lcc->lcc_env;
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page = lcc->lcc_page;
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io = lcc->lcc_io;
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LASSERT(cl_page_is_owned(page, io));
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LASSERT(from <= to);
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if (from != to) /* handle short write case. */
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result = cl_io_commit_write(env, io, page, from, to);
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if (cl_page_is_owned(page, io))
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cl_page_unassume(env, io, page);
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/*
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* Release reference acquired by ll_prepare_write().
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*/
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lu_ref_del(&page->cp_reference, "prepare_write", current);
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cl_page_put(env, page);
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ll_cl_fini(lcc);
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return result;
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}
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struct obd_capa *cl_capa_lookup(struct inode *inode, enum cl_req_type crt)
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{
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__u64 opc;
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opc = crt == CRT_WRITE ? CAPA_OPC_OSS_WRITE : CAPA_OPC_OSS_RW;
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return ll_osscapa_get(inode, opc);
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}
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static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which);
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/**
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* Get readahead pages from the filesystem readahead pool of the client for a
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* thread.
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*
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* /param sbi superblock for filesystem readahead state ll_ra_info
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* /param ria per-thread readahead state
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* /param pages number of pages requested for readahead for the thread.
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*
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* WARNING: This algorithm is used to reduce contention on sbi->ll_lock.
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* It should work well if the ra_max_pages is much greater than the single
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* file's read-ahead window, and not too many threads contending for
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* these readahead pages.
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*
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* TODO: There may be a 'global sync problem' if many threads are trying
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* to get an ra budget that is larger than the remaining readahead pages
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* and reach here at exactly the same time. They will compute /a ret to
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* consume the remaining pages, but will fail at atomic_add_return() and
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* get a zero ra window, although there is still ra space remaining. - Jay */
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static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
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struct ra_io_arg *ria,
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unsigned long pages)
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{
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struct ll_ra_info *ra = &sbi->ll_ra_info;
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long ret;
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/* If read-ahead pages left are less than 1M, do not do read-ahead,
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* otherwise it will form small read RPC(< 1M), which hurt server
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* performance a lot. */
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ret = min(ra->ra_max_pages - atomic_read(&ra->ra_cur_pages), pages);
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if (ret < 0 || ret < min_t(long, PTLRPC_MAX_BRW_PAGES, pages))
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GOTO(out, ret = 0);
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/* If the non-strided (ria_pages == 0) readahead window
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* (ria_start + ret) has grown across an RPC boundary, then trim
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* readahead size by the amount beyond the RPC so it ends on an
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* RPC boundary. If the readahead window is already ending on
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* an RPC boundary (beyond_rpc == 0), or smaller than a full
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* RPC (beyond_rpc < ret) the readahead size is unchanged.
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* The (beyond_rpc != 0) check is skipped since the conditional
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* branch is more expensive than subtracting zero from the result.
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*
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* Strided read is left unaligned to avoid small fragments beyond
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* the RPC boundary from needing an extra read RPC. */
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if (ria->ria_pages == 0) {
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long beyond_rpc = (ria->ria_start + ret) % PTLRPC_MAX_BRW_PAGES;
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if (/* beyond_rpc != 0 && */ beyond_rpc < ret)
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ret -= beyond_rpc;
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}
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if (atomic_add_return(ret, &ra->ra_cur_pages) > ra->ra_max_pages) {
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atomic_sub(ret, &ra->ra_cur_pages);
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ret = 0;
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}
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out:
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return ret;
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}
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void ll_ra_count_put(struct ll_sb_info *sbi, unsigned long len)
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{
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struct ll_ra_info *ra = &sbi->ll_ra_info;
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atomic_sub(len, &ra->ra_cur_pages);
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}
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static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which)
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{
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LASSERTF(which >= 0 && which < _NR_RA_STAT, "which: %u\n", which);
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lprocfs_counter_incr(sbi->ll_ra_stats, which);
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}
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void ll_ra_stats_inc(struct address_space *mapping, enum ra_stat which)
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{
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struct ll_sb_info *sbi = ll_i2sbi(mapping->host);
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ll_ra_stats_inc_sbi(sbi, which);
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}
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#define RAS_CDEBUG(ras) \
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CDEBUG(D_READA, \
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"lrp %lu cr %lu cp %lu ws %lu wl %lu nra %lu r %lu ri %lu" \
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"csr %lu sf %lu sp %lu sl %lu \n", \
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ras->ras_last_readpage, ras->ras_consecutive_requests, \
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ras->ras_consecutive_pages, ras->ras_window_start, \
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ras->ras_window_len, ras->ras_next_readahead, \
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ras->ras_requests, ras->ras_request_index, \
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ras->ras_consecutive_stride_requests, ras->ras_stride_offset, \
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ras->ras_stride_pages, ras->ras_stride_length)
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static int index_in_window(unsigned long index, unsigned long point,
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unsigned long before, unsigned long after)
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{
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unsigned long start = point - before, end = point + after;
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if (start > point)
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start = 0;
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if (end < point)
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end = ~0;
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return start <= index && index <= end;
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}
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static struct ll_readahead_state *ll_ras_get(struct file *f)
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{
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struct ll_file_data *fd;
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fd = LUSTRE_FPRIVATE(f);
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return &fd->fd_ras;
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}
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void ll_ra_read_in(struct file *f, struct ll_ra_read *rar)
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{
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struct ll_readahead_state *ras;
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ras = ll_ras_get(f);
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spin_lock(&ras->ras_lock);
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ras->ras_requests++;
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ras->ras_request_index = 0;
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ras->ras_consecutive_requests++;
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rar->lrr_reader = current;
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list_add(&rar->lrr_linkage, &ras->ras_read_beads);
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spin_unlock(&ras->ras_lock);
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}
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void ll_ra_read_ex(struct file *f, struct ll_ra_read *rar)
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{
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struct ll_readahead_state *ras;
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ras = ll_ras_get(f);
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spin_lock(&ras->ras_lock);
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list_del_init(&rar->lrr_linkage);
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spin_unlock(&ras->ras_lock);
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}
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static struct ll_ra_read *ll_ra_read_get_locked(struct ll_readahead_state *ras)
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{
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struct ll_ra_read *scan;
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list_for_each_entry(scan, &ras->ras_read_beads, lrr_linkage) {
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if (scan->lrr_reader == current)
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return scan;
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}
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return NULL;
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}
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struct ll_ra_read *ll_ra_read_get(struct file *f)
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{
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struct ll_readahead_state *ras;
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struct ll_ra_read *bead;
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ras = ll_ras_get(f);
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spin_lock(&ras->ras_lock);
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bead = ll_ra_read_get_locked(ras);
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spin_unlock(&ras->ras_lock);
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return bead;
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}
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static int cl_read_ahead_page(const struct lu_env *env, struct cl_io *io,
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struct cl_page_list *queue, struct cl_page *page,
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struct page *vmpage)
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{
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struct ccc_page *cp;
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int rc;
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rc = 0;
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cl_page_assume(env, io, page);
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lu_ref_add(&page->cp_reference, "ra", current);
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cp = cl2ccc_page(cl_page_at(page, &vvp_device_type));
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if (!cp->cpg_defer_uptodate && !PageUptodate(vmpage)) {
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rc = cl_page_is_under_lock(env, io, page);
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if (rc == -EBUSY) {
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cp->cpg_defer_uptodate = 1;
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cp->cpg_ra_used = 0;
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cl_page_list_add(queue, page);
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rc = 1;
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} else {
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cl_page_delete(env, page);
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rc = -ENOLCK;
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}
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} else {
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/* skip completed pages */
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cl_page_unassume(env, io, page);
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}
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lu_ref_del(&page->cp_reference, "ra", current);
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cl_page_put(env, page);
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return rc;
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}
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/**
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* Initiates read-ahead of a page with given index.
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*
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* \retval +ve: page was added to \a queue.
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*
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* \retval -ENOLCK: there is no extent lock for this part of a file, stop
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* read-ahead.
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*
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* \retval -ve, 0: page wasn't added to \a queue for other reason.
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*/
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static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
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struct cl_page_list *queue,
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pgoff_t index, struct address_space *mapping)
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{
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struct page *vmpage;
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struct cl_object *clob = ll_i2info(mapping->host)->lli_clob;
|
|
struct cl_page *page;
|
|
enum ra_stat which = _NR_RA_STAT; /* keep gcc happy */
|
|
int rc = 0;
|
|
const char *msg = NULL;
|
|
|
|
vmpage = grab_cache_page_nowait(mapping, index);
|
|
if (vmpage != NULL) {
|
|
/* Check if vmpage was truncated or reclaimed */
|
|
if (vmpage->mapping == mapping) {
|
|
page = cl_page_find(env, clob, vmpage->index,
|
|
vmpage, CPT_CACHEABLE);
|
|
if (!IS_ERR(page)) {
|
|
rc = cl_read_ahead_page(env, io, queue,
|
|
page, vmpage);
|
|
if (rc == -ENOLCK) {
|
|
which = RA_STAT_FAILED_MATCH;
|
|
msg = "lock match failed";
|
|
}
|
|
} else {
|
|
which = RA_STAT_FAILED_GRAB_PAGE;
|
|
msg = "cl_page_find failed";
|
|
}
|
|
} else {
|
|
which = RA_STAT_WRONG_GRAB_PAGE;
|
|
msg = "g_c_p_n returned invalid page";
|
|
}
|
|
if (rc != 1)
|
|
unlock_page(vmpage);
|
|
page_cache_release(vmpage);
|
|
} else {
|
|
which = RA_STAT_FAILED_GRAB_PAGE;
|
|
msg = "g_c_p_n failed";
|
|
}
|
|
if (msg != NULL) {
|
|
ll_ra_stats_inc(mapping, which);
|
|
CDEBUG(D_READA, "%s\n", msg);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
#define RIA_DEBUG(ria) \
|
|
CDEBUG(D_READA, "rs %lu re %lu ro %lu rl %lu rp %lu\n", \
|
|
ria->ria_start, ria->ria_end, ria->ria_stoff, ria->ria_length,\
|
|
ria->ria_pages)
|
|
|
|
/* Limit this to the blocksize instead of PTLRPC_BRW_MAX_SIZE, since we don't
|
|
* know what the actual RPC size is. If this needs to change, it makes more
|
|
* sense to tune the i_blkbits value for the file based on the OSTs it is
|
|
* striped over, rather than having a constant value for all files here. */
|
|
|
|
/* RAS_INCREASE_STEP should be (1UL << (inode->i_blkbits - PAGE_CACHE_SHIFT)).
|
|
* Temporarily set RAS_INCREASE_STEP to 1MB. After 4MB RPC is enabled
|
|
* by default, this should be adjusted corresponding with max_read_ahead_mb
|
|
* and max_read_ahead_per_file_mb otherwise the readahead budget can be used
|
|
* up quickly which will affect read performance significantly. See LU-2816 */
|
|
#define RAS_INCREASE_STEP(inode) (ONE_MB_BRW_SIZE >> PAGE_CACHE_SHIFT)
|
|
|
|
static inline int stride_io_mode(struct ll_readahead_state *ras)
|
|
{
|
|
return ras->ras_consecutive_stride_requests > 1;
|
|
}
|
|
/* The function calculates how much pages will be read in
|
|
* [off, off + length], in such stride IO area,
|
|
* stride_offset = st_off, stride_length = st_len,
|
|
* stride_pages = st_pgs
|
|
*
|
|
* |------------------|*****|------------------|*****|------------|*****|....
|
|
* st_off
|
|
* |--- st_pgs ---|
|
|
* |----- st_len -----|
|
|
*
|
|
* How many pages it should read in such pattern
|
|
* |-------------------------------------------------------------|
|
|
* off
|
|
* |<------ length ------->|
|
|
*
|
|
* = |<----->| + |-------------------------------------| + |---|
|
|
* start_left st_pgs * i end_left
|
|
*/
|
|
static unsigned long
|
|
stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs,
|
|
unsigned long off, unsigned long length)
|
|
{
|
|
__u64 start = off > st_off ? off - st_off : 0;
|
|
__u64 end = off + length > st_off ? off + length - st_off : 0;
|
|
unsigned long start_left = 0;
|
|
unsigned long end_left = 0;
|
|
unsigned long pg_count;
|
|
|
|
if (st_len == 0 || length == 0 || end == 0)
|
|
return length;
|
|
|
|
start_left = do_div(start, st_len);
|
|
if (start_left < st_pgs)
|
|
start_left = st_pgs - start_left;
|
|
else
|
|
start_left = 0;
|
|
|
|
end_left = do_div(end, st_len);
|
|
if (end_left > st_pgs)
|
|
end_left = st_pgs;
|
|
|
|
CDEBUG(D_READA, "start %llu, end %llu start_left %lu end_left %lu \n",
|
|
start, end, start_left, end_left);
|
|
|
|
if (start == end)
|
|
pg_count = end_left - (st_pgs - start_left);
|
|
else
|
|
pg_count = start_left + st_pgs * (end - start - 1) + end_left;
|
|
|
|
CDEBUG(D_READA, "st_off %lu, st_len %lu st_pgs %lu off %lu length %lu"
|
|
"pgcount %lu\n", st_off, st_len, st_pgs, off, length, pg_count);
|
|
|
|
return pg_count;
|
|
}
|
|
|
|
static int ria_page_count(struct ra_io_arg *ria)
|
|
{
|
|
__u64 length = ria->ria_end >= ria->ria_start ?
|
|
ria->ria_end - ria->ria_start + 1 : 0;
|
|
|
|
return stride_pg_count(ria->ria_stoff, ria->ria_length,
|
|
ria->ria_pages, ria->ria_start,
|
|
length);
|
|
}
|
|
|
|
/*Check whether the index is in the defined ra-window */
|
|
static int ras_inside_ra_window(unsigned long idx, struct ra_io_arg *ria)
|
|
{
|
|
/* If ria_length == ria_pages, it means non-stride I/O mode,
|
|
* idx should always inside read-ahead window in this case
|
|
* For stride I/O mode, just check whether the idx is inside
|
|
* the ria_pages. */
|
|
return ria->ria_length == 0 || ria->ria_length == ria->ria_pages ||
|
|
(idx >= ria->ria_stoff && (idx - ria->ria_stoff) %
|
|
ria->ria_length < ria->ria_pages);
|
|
}
|
|
|
|
static int ll_read_ahead_pages(const struct lu_env *env,
|
|
struct cl_io *io, struct cl_page_list *queue,
|
|
struct ra_io_arg *ria,
|
|
unsigned long *reserved_pages,
|
|
struct address_space *mapping,
|
|
unsigned long *ra_end)
|
|
{
|
|
int rc, count = 0, stride_ria;
|
|
unsigned long page_idx;
|
|
|
|
LASSERT(ria != NULL);
|
|
RIA_DEBUG(ria);
|
|
|
|
stride_ria = ria->ria_length > ria->ria_pages && ria->ria_pages > 0;
|
|
for (page_idx = ria->ria_start; page_idx <= ria->ria_end &&
|
|
*reserved_pages > 0; page_idx++) {
|
|
if (ras_inside_ra_window(page_idx, ria)) {
|
|
/* If the page is inside the read-ahead window*/
|
|
rc = ll_read_ahead_page(env, io, queue,
|
|
page_idx, mapping);
|
|
if (rc == 1) {
|
|
(*reserved_pages)--;
|
|
count ++;
|
|
} else if (rc == -ENOLCK)
|
|
break;
|
|
} else if (stride_ria) {
|
|
/* If it is not in the read-ahead window, and it is
|
|
* read-ahead mode, then check whether it should skip
|
|
* the stride gap */
|
|
pgoff_t offset;
|
|
/* FIXME: This assertion only is valid when it is for
|
|
* forward read-ahead, it will be fixed when backward
|
|
* read-ahead is implemented */
|
|
LASSERTF(page_idx > ria->ria_stoff, "Invalid page_idx %lu"
|
|
"rs %lu re %lu ro %lu rl %lu rp %lu\n", page_idx,
|
|
ria->ria_start, ria->ria_end, ria->ria_stoff,
|
|
ria->ria_length, ria->ria_pages);
|
|
offset = page_idx - ria->ria_stoff;
|
|
offset = offset % (ria->ria_length);
|
|
if (offset > ria->ria_pages) {
|
|
page_idx += ria->ria_length - offset;
|
|
CDEBUG(D_READA, "i %lu skip %lu \n", page_idx,
|
|
ria->ria_length - offset);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
*ra_end = page_idx;
|
|
return count;
|
|
}
|
|
|
|
int ll_readahead(const struct lu_env *env, struct cl_io *io,
|
|
struct ll_readahead_state *ras, struct address_space *mapping,
|
|
struct cl_page_list *queue, int flags)
|
|
{
|
|
struct vvp_io *vio = vvp_env_io(env);
|
|
struct vvp_thread_info *vti = vvp_env_info(env);
|
|
struct cl_attr *attr = ccc_env_thread_attr(env);
|
|
unsigned long start = 0, end = 0, reserved;
|
|
unsigned long ra_end, len;
|
|
struct inode *inode;
|
|
struct ll_ra_read *bead;
|
|
struct ra_io_arg *ria = &vti->vti_ria;
|
|
struct ll_inode_info *lli;
|
|
struct cl_object *clob;
|
|
int ret = 0;
|
|
__u64 kms;
|
|
|
|
inode = mapping->host;
|
|
lli = ll_i2info(inode);
|
|
clob = lli->lli_clob;
|
|
|
|
memset(ria, 0, sizeof(*ria));
|
|
|
|
cl_object_attr_lock(clob);
|
|
ret = cl_object_attr_get(env, clob, attr);
|
|
cl_object_attr_unlock(clob);
|
|
|
|
if (ret != 0)
|
|
return ret;
|
|
kms = attr->cat_kms;
|
|
if (kms == 0) {
|
|
ll_ra_stats_inc(mapping, RA_STAT_ZERO_LEN);
|
|
return 0;
|
|
}
|
|
|
|
spin_lock(&ras->ras_lock);
|
|
if (vio->cui_ra_window_set)
|
|
bead = &vio->cui_bead;
|
|
else
|
|
bead = NULL;
|
|
|
|
/* Enlarge the RA window to encompass the full read */
|
|
if (bead != NULL && ras->ras_window_start + ras->ras_window_len <
|
|
bead->lrr_start + bead->lrr_count) {
|
|
ras->ras_window_len = bead->lrr_start + bead->lrr_count -
|
|
ras->ras_window_start;
|
|
}
|
|
/* Reserve a part of the read-ahead window that we'll be issuing */
|
|
if (ras->ras_window_len) {
|
|
start = ras->ras_next_readahead;
|
|
end = ras->ras_window_start + ras->ras_window_len - 1;
|
|
}
|
|
if (end != 0) {
|
|
unsigned long rpc_boundary;
|
|
/*
|
|
* Align RA window to an optimal boundary.
|
|
*
|
|
* XXX This would be better to align to cl_max_pages_per_rpc
|
|
* instead of PTLRPC_MAX_BRW_PAGES, because the RPC size may
|
|
* be aligned to the RAID stripe size in the future and that
|
|
* is more important than the RPC size.
|
|
*/
|
|
/* Note: we only trim the RPC, instead of extending the RPC
|
|
* to the boundary, so to avoid reading too much pages during
|
|
* random reading. */
|
|
rpc_boundary = ((end + 1) & (~(PTLRPC_MAX_BRW_PAGES - 1)));
|
|
if (rpc_boundary > 0)
|
|
rpc_boundary--;
|
|
|
|
if (rpc_boundary > start)
|
|
end = rpc_boundary;
|
|
|
|
/* Truncate RA window to end of file */
|
|
end = min(end, (unsigned long)((kms - 1) >> PAGE_CACHE_SHIFT));
|
|
|
|
ras->ras_next_readahead = max(end, end + 1);
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
ria->ria_start = start;
|
|
ria->ria_end = end;
|
|
/* If stride I/O mode is detected, get stride window*/
|
|
if (stride_io_mode(ras)) {
|
|
ria->ria_stoff = ras->ras_stride_offset;
|
|
ria->ria_length = ras->ras_stride_length;
|
|
ria->ria_pages = ras->ras_stride_pages;
|
|
}
|
|
spin_unlock(&ras->ras_lock);
|
|
|
|
if (end == 0) {
|
|
ll_ra_stats_inc(mapping, RA_STAT_ZERO_WINDOW);
|
|
return 0;
|
|
}
|
|
len = ria_page_count(ria);
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
reserved = ll_ra_count_get(ll_i2sbi(inode), ria, len);
|
|
if (reserved < len)
|
|
ll_ra_stats_inc(mapping, RA_STAT_MAX_IN_FLIGHT);
|
|
|
|
CDEBUG(D_READA, "reserved page %lu ra_cur %d ra_max %lu\n", reserved,
|
|
atomic_read(&ll_i2sbi(inode)->ll_ra_info.ra_cur_pages),
|
|
ll_i2sbi(inode)->ll_ra_info.ra_max_pages);
|
|
|
|
ret = ll_read_ahead_pages(env, io, queue,
|
|
ria, &reserved, mapping, &ra_end);
|
|
|
|
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
|
|
if (reserved != 0)
|
|
ll_ra_count_put(ll_i2sbi(inode), reserved);
|
|
|
|
if (ra_end == end + 1 && ra_end == (kms >> PAGE_CACHE_SHIFT))
|
|
ll_ra_stats_inc(mapping, RA_STAT_EOF);
|
|
|
|
/* if we didn't get to the end of the region we reserved from
|
|
* the ras we need to go back and update the ras so that the
|
|
* next read-ahead tries from where we left off. we only do so
|
|
* if the region we failed to issue read-ahead on is still ahead
|
|
* of the app and behind the next index to start read-ahead from */
|
|
CDEBUG(D_READA, "ra_end %lu end %lu stride end %lu \n",
|
|
ra_end, end, ria->ria_end);
|
|
|
|
if (ra_end != end + 1) {
|
|
spin_lock(&ras->ras_lock);
|
|
if (ra_end < ras->ras_next_readahead &&
|
|
index_in_window(ra_end, ras->ras_window_start, 0,
|
|
ras->ras_window_len)) {
|
|
ras->ras_next_readahead = ra_end;
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
spin_unlock(&ras->ras_lock);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void ras_set_start(struct inode *inode, struct ll_readahead_state *ras,
|
|
unsigned long index)
|
|
{
|
|
ras->ras_window_start = index & (~(RAS_INCREASE_STEP(inode) - 1));
|
|
}
|
|
|
|
/* called with the ras_lock held or from places where it doesn't matter */
|
|
static void ras_reset(struct inode *inode, struct ll_readahead_state *ras,
|
|
unsigned long index)
|
|
{
|
|
ras->ras_last_readpage = index;
|
|
ras->ras_consecutive_requests = 0;
|
|
ras->ras_consecutive_pages = 0;
|
|
ras->ras_window_len = 0;
|
|
ras_set_start(inode, ras, index);
|
|
ras->ras_next_readahead = max(ras->ras_window_start, index);
|
|
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
|
|
/* called with the ras_lock held or from places where it doesn't matter */
|
|
static void ras_stride_reset(struct ll_readahead_state *ras)
|
|
{
|
|
ras->ras_consecutive_stride_requests = 0;
|
|
ras->ras_stride_length = 0;
|
|
ras->ras_stride_pages = 0;
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
|
|
void ll_readahead_init(struct inode *inode, struct ll_readahead_state *ras)
|
|
{
|
|
spin_lock_init(&ras->ras_lock);
|
|
ras_reset(inode, ras, 0);
|
|
ras->ras_requests = 0;
|
|
INIT_LIST_HEAD(&ras->ras_read_beads);
|
|
}
|
|
|
|
/*
|
|
* Check whether the read request is in the stride window.
|
|
* If it is in the stride window, return 1, otherwise return 0.
|
|
*/
|
|
static int index_in_stride_window(struct ll_readahead_state *ras,
|
|
unsigned long index)
|
|
{
|
|
unsigned long stride_gap;
|
|
|
|
if (ras->ras_stride_length == 0 || ras->ras_stride_pages == 0 ||
|
|
ras->ras_stride_pages == ras->ras_stride_length)
|
|
return 0;
|
|
|
|
stride_gap = index - ras->ras_last_readpage - 1;
|
|
|
|
/* If it is contiguous read */
|
|
if (stride_gap == 0)
|
|
return ras->ras_consecutive_pages + 1 <= ras->ras_stride_pages;
|
|
|
|
/* Otherwise check the stride by itself */
|
|
return (ras->ras_stride_length - ras->ras_stride_pages) == stride_gap &&
|
|
ras->ras_consecutive_pages == ras->ras_stride_pages;
|
|
}
|
|
|
|
static void ras_update_stride_detector(struct ll_readahead_state *ras,
|
|
unsigned long index)
|
|
{
|
|
unsigned long stride_gap = index - ras->ras_last_readpage - 1;
|
|
|
|
if (!stride_io_mode(ras) && (stride_gap != 0 ||
|
|
ras->ras_consecutive_stride_requests == 0)) {
|
|
ras->ras_stride_pages = ras->ras_consecutive_pages;
|
|
ras->ras_stride_length = stride_gap +ras->ras_consecutive_pages;
|
|
}
|
|
LASSERT(ras->ras_request_index == 0);
|
|
LASSERT(ras->ras_consecutive_stride_requests == 0);
|
|
|
|
if (index <= ras->ras_last_readpage) {
|
|
/*Reset stride window for forward read*/
|
|
ras_stride_reset(ras);
|
|
return;
|
|
}
|
|
|
|
ras->ras_stride_pages = ras->ras_consecutive_pages;
|
|
ras->ras_stride_length = stride_gap +ras->ras_consecutive_pages;
|
|
|
|
RAS_CDEBUG(ras);
|
|
return;
|
|
}
|
|
|
|
static unsigned long
|
|
stride_page_count(struct ll_readahead_state *ras, unsigned long len)
|
|
{
|
|
return stride_pg_count(ras->ras_stride_offset, ras->ras_stride_length,
|
|
ras->ras_stride_pages, ras->ras_stride_offset,
|
|
len);
|
|
}
|
|
|
|
/* Stride Read-ahead window will be increased inc_len according to
|
|
* stride I/O pattern */
|
|
static void ras_stride_increase_window(struct ll_readahead_state *ras,
|
|
struct ll_ra_info *ra,
|
|
unsigned long inc_len)
|
|
{
|
|
unsigned long left, step, window_len;
|
|
unsigned long stride_len;
|
|
|
|
LASSERT(ras->ras_stride_length > 0);
|
|
LASSERTF(ras->ras_window_start + ras->ras_window_len
|
|
>= ras->ras_stride_offset, "window_start %lu, window_len %lu"
|
|
" stride_offset %lu\n", ras->ras_window_start,
|
|
ras->ras_window_len, ras->ras_stride_offset);
|
|
|
|
stride_len = ras->ras_window_start + ras->ras_window_len -
|
|
ras->ras_stride_offset;
|
|
|
|
left = stride_len % ras->ras_stride_length;
|
|
window_len = ras->ras_window_len - left;
|
|
|
|
if (left < ras->ras_stride_pages)
|
|
left += inc_len;
|
|
else
|
|
left = ras->ras_stride_pages + inc_len;
|
|
|
|
LASSERT(ras->ras_stride_pages != 0);
|
|
|
|
step = left / ras->ras_stride_pages;
|
|
left %= ras->ras_stride_pages;
|
|
|
|
window_len += step * ras->ras_stride_length + left;
|
|
|
|
if (stride_page_count(ras, window_len) <= ra->ra_max_pages_per_file)
|
|
ras->ras_window_len = window_len;
|
|
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
|
|
static void ras_increase_window(struct inode *inode,
|
|
struct ll_readahead_state *ras,
|
|
struct ll_ra_info *ra)
|
|
{
|
|
/* The stretch of ra-window should be aligned with max rpc_size
|
|
* but current clio architecture does not support retrieve such
|
|
* information from lower layer. FIXME later
|
|
*/
|
|
if (stride_io_mode(ras))
|
|
ras_stride_increase_window(ras, ra, RAS_INCREASE_STEP(inode));
|
|
else
|
|
ras->ras_window_len = min(ras->ras_window_len +
|
|
RAS_INCREASE_STEP(inode),
|
|
ra->ra_max_pages_per_file);
|
|
}
|
|
|
|
void ras_update(struct ll_sb_info *sbi, struct inode *inode,
|
|
struct ll_readahead_state *ras, unsigned long index,
|
|
unsigned hit)
|
|
{
|
|
struct ll_ra_info *ra = &sbi->ll_ra_info;
|
|
int zero = 0, stride_detect = 0, ra_miss = 0;
|
|
|
|
spin_lock(&ras->ras_lock);
|
|
|
|
ll_ra_stats_inc_sbi(sbi, hit ? RA_STAT_HIT : RA_STAT_MISS);
|
|
|
|
/* reset the read-ahead window in two cases. First when the app seeks
|
|
* or reads to some other part of the file. Secondly if we get a
|
|
* read-ahead miss that we think we've previously issued. This can
|
|
* be a symptom of there being so many read-ahead pages that the VM is
|
|
* reclaiming it before we get to it. */
|
|
if (!index_in_window(index, ras->ras_last_readpage, 8, 8)) {
|
|
zero = 1;
|
|
ll_ra_stats_inc_sbi(sbi, RA_STAT_DISTANT_READPAGE);
|
|
} else if (!hit && ras->ras_window_len &&
|
|
index < ras->ras_next_readahead &&
|
|
index_in_window(index, ras->ras_window_start, 0,
|
|
ras->ras_window_len)) {
|
|
ra_miss = 1;
|
|
ll_ra_stats_inc_sbi(sbi, RA_STAT_MISS_IN_WINDOW);
|
|
}
|
|
|
|
/* On the second access to a file smaller than the tunable
|
|
* ra_max_read_ahead_whole_pages trigger RA on all pages in the
|
|
* file up to ra_max_pages_per_file. This is simply a best effort
|
|
* and only occurs once per open file. Normal RA behavior is reverted
|
|
* to for subsequent IO. The mmap case does not increment
|
|
* ras_requests and thus can never trigger this behavior. */
|
|
if (ras->ras_requests == 2 && !ras->ras_request_index) {
|
|
__u64 kms_pages;
|
|
|
|
kms_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
|
|
PAGE_CACHE_SHIFT;
|
|
|
|
CDEBUG(D_READA, "kmsp %llu mwp %lu mp %lu\n", kms_pages,
|
|
ra->ra_max_read_ahead_whole_pages, ra->ra_max_pages_per_file);
|
|
|
|
if (kms_pages &&
|
|
kms_pages <= ra->ra_max_read_ahead_whole_pages) {
|
|
ras->ras_window_start = 0;
|
|
ras->ras_last_readpage = 0;
|
|
ras->ras_next_readahead = 0;
|
|
ras->ras_window_len = min(ra->ra_max_pages_per_file,
|
|
ra->ra_max_read_ahead_whole_pages);
|
|
GOTO(out_unlock, 0);
|
|
}
|
|
}
|
|
if (zero) {
|
|
/* check whether it is in stride I/O mode*/
|
|
if (!index_in_stride_window(ras, index)) {
|
|
if (ras->ras_consecutive_stride_requests == 0 &&
|
|
ras->ras_request_index == 0) {
|
|
ras_update_stride_detector(ras, index);
|
|
ras->ras_consecutive_stride_requests++;
|
|
} else {
|
|
ras_stride_reset(ras);
|
|
}
|
|
ras_reset(inode, ras, index);
|
|
ras->ras_consecutive_pages++;
|
|
GOTO(out_unlock, 0);
|
|
} else {
|
|
ras->ras_consecutive_pages = 0;
|
|
ras->ras_consecutive_requests = 0;
|
|
if (++ras->ras_consecutive_stride_requests > 1)
|
|
stride_detect = 1;
|
|
RAS_CDEBUG(ras);
|
|
}
|
|
} else {
|
|
if (ra_miss) {
|
|
if (index_in_stride_window(ras, index) &&
|
|
stride_io_mode(ras)) {
|
|
/*If stride-RA hit cache miss, the stride dector
|
|
*will not be reset to avoid the overhead of
|
|
*redetecting read-ahead mode */
|
|
if (index != ras->ras_last_readpage + 1)
|
|
ras->ras_consecutive_pages = 0;
|
|
ras_reset(inode, ras, index);
|
|
RAS_CDEBUG(ras);
|
|
} else {
|
|
/* Reset both stride window and normal RA
|
|
* window */
|
|
ras_reset(inode, ras, index);
|
|
ras->ras_consecutive_pages++;
|
|
ras_stride_reset(ras);
|
|
GOTO(out_unlock, 0);
|
|
}
|
|
} else if (stride_io_mode(ras)) {
|
|
/* If this is contiguous read but in stride I/O mode
|
|
* currently, check whether stride step still is valid,
|
|
* if invalid, it will reset the stride ra window*/
|
|
if (!index_in_stride_window(ras, index)) {
|
|
/* Shrink stride read-ahead window to be zero */
|
|
ras_stride_reset(ras);
|
|
ras->ras_window_len = 0;
|
|
ras->ras_next_readahead = index;
|
|
}
|
|
}
|
|
}
|
|
ras->ras_consecutive_pages++;
|
|
ras->ras_last_readpage = index;
|
|
ras_set_start(inode, ras, index);
|
|
|
|
if (stride_io_mode(ras))
|
|
/* Since stride readahead is sensitive to the offset
|
|
* of read-ahead, so we use original offset here,
|
|
* instead of ras_window_start, which is RPC aligned */
|
|
ras->ras_next_readahead = max(index, ras->ras_next_readahead);
|
|
else
|
|
ras->ras_next_readahead = max(ras->ras_window_start,
|
|
ras->ras_next_readahead);
|
|
RAS_CDEBUG(ras);
|
|
|
|
/* Trigger RA in the mmap case where ras_consecutive_requests
|
|
* is not incremented and thus can't be used to trigger RA */
|
|
if (!ras->ras_window_len && ras->ras_consecutive_pages == 4) {
|
|
ras->ras_window_len = RAS_INCREASE_STEP(inode);
|
|
GOTO(out_unlock, 0);
|
|
}
|
|
|
|
/* Initially reset the stride window offset to next_readahead*/
|
|
if (ras->ras_consecutive_stride_requests == 2 && stride_detect) {
|
|
/**
|
|
* Once stride IO mode is detected, next_readahead should be
|
|
* reset to make sure next_readahead > stride offset
|
|
*/
|
|
ras->ras_next_readahead = max(index, ras->ras_next_readahead);
|
|
ras->ras_stride_offset = index;
|
|
ras->ras_window_len = RAS_INCREASE_STEP(inode);
|
|
}
|
|
|
|
/* The initial ras_window_len is set to the request size. To avoid
|
|
* uselessly reading and discarding pages for random IO the window is
|
|
* only increased once per consecutive request received. */
|
|
if ((ras->ras_consecutive_requests > 1 || stride_detect) &&
|
|
!ras->ras_request_index)
|
|
ras_increase_window(inode, ras, ra);
|
|
out_unlock:
|
|
RAS_CDEBUG(ras);
|
|
ras->ras_request_index++;
|
|
spin_unlock(&ras->ras_lock);
|
|
return;
|
|
}
|
|
|
|
int ll_writepage(struct page *vmpage, struct writeback_control *wbc)
|
|
{
|
|
struct inode *inode = vmpage->mapping->host;
|
|
struct ll_inode_info *lli = ll_i2info(inode);
|
|
struct lu_env *env;
|
|
struct cl_io *io;
|
|
struct cl_page *page;
|
|
struct cl_object *clob;
|
|
struct cl_env_nest nest;
|
|
bool redirtied = false;
|
|
bool unlocked = false;
|
|
int result;
|
|
|
|
LASSERT(PageLocked(vmpage));
|
|
LASSERT(!PageWriteback(vmpage));
|
|
|
|
LASSERT(ll_i2dtexp(inode) != NULL);
|
|
|
|
env = cl_env_nested_get(&nest);
|
|
if (IS_ERR(env))
|
|
GOTO(out, result = PTR_ERR(env));
|
|
|
|
clob = ll_i2info(inode)->lli_clob;
|
|
LASSERT(clob != NULL);
|
|
|
|
io = ccc_env_thread_io(env);
|
|
io->ci_obj = clob;
|
|
io->ci_ignore_layout = 1;
|
|
result = cl_io_init(env, io, CIT_MISC, clob);
|
|
if (result == 0) {
|
|
page = cl_page_find(env, clob, vmpage->index,
|
|
vmpage, CPT_CACHEABLE);
|
|
if (!IS_ERR(page)) {
|
|
lu_ref_add(&page->cp_reference, "writepage",
|
|
current);
|
|
cl_page_assume(env, io, page);
|
|
result = cl_page_flush(env, io, page);
|
|
if (result != 0) {
|
|
/*
|
|
* Re-dirty page on error so it retries write,
|
|
* but not in case when IO has actually
|
|
* occurred and completed with an error.
|
|
*/
|
|
if (!PageError(vmpage)) {
|
|
redirty_page_for_writepage(wbc, vmpage);
|
|
result = 0;
|
|
redirtied = true;
|
|
}
|
|
}
|
|
cl_page_disown(env, io, page);
|
|
unlocked = true;
|
|
lu_ref_del(&page->cp_reference,
|
|
"writepage", current);
|
|
cl_page_put(env, page);
|
|
} else {
|
|
result = PTR_ERR(page);
|
|
}
|
|
}
|
|
cl_io_fini(env, io);
|
|
|
|
if (redirtied && wbc->sync_mode == WB_SYNC_ALL) {
|
|
loff_t offset = cl_offset(clob, vmpage->index);
|
|
|
|
/* Flush page failed because the extent is being written out.
|
|
* Wait for the write of extent to be finished to avoid
|
|
* breaking kernel which assumes ->writepage should mark
|
|
* PageWriteback or clean the page. */
|
|
result = cl_sync_file_range(inode, offset,
|
|
offset + PAGE_CACHE_SIZE - 1,
|
|
CL_FSYNC_LOCAL, 1);
|
|
if (result > 0) {
|
|
/* actually we may have written more than one page.
|
|
* decreasing this page because the caller will count
|
|
* it. */
|
|
wbc->nr_to_write -= result - 1;
|
|
result = 0;
|
|
}
|
|
}
|
|
|
|
cl_env_nested_put(&nest, env);
|
|
GOTO(out, result);
|
|
|
|
out:
|
|
if (result < 0) {
|
|
if (!lli->lli_async_rc)
|
|
lli->lli_async_rc = result;
|
|
SetPageError(vmpage);
|
|
if (!unlocked)
|
|
unlock_page(vmpage);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct ll_sb_info *sbi = ll_i2sbi(inode);
|
|
loff_t start;
|
|
loff_t end;
|
|
enum cl_fsync_mode mode;
|
|
int range_whole = 0;
|
|
int result;
|
|
int ignore_layout = 0;
|
|
|
|
if (wbc->range_cyclic) {
|
|
start = mapping->writeback_index << PAGE_CACHE_SHIFT;
|
|
end = OBD_OBJECT_EOF;
|
|
} else {
|
|
start = wbc->range_start;
|
|
end = wbc->range_end;
|
|
if (end == LLONG_MAX) {
|
|
end = OBD_OBJECT_EOF;
|
|
range_whole = start == 0;
|
|
}
|
|
}
|
|
|
|
mode = CL_FSYNC_NONE;
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
mode = CL_FSYNC_LOCAL;
|
|
|
|
if (sbi->ll_umounting)
|
|
/* if the mountpoint is being umounted, all pages have to be
|
|
* evicted to avoid hitting LBUG when truncate_inode_pages()
|
|
* is called later on. */
|
|
ignore_layout = 1;
|
|
result = cl_sync_file_range(inode, start, end, mode, ignore_layout);
|
|
if (result > 0) {
|
|
wbc->nr_to_write -= result;
|
|
result = 0;
|
|
}
|
|
|
|
if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) {
|
|
if (end == OBD_OBJECT_EOF)
|
|
end = i_size_read(inode);
|
|
mapping->writeback_index = (end >> PAGE_CACHE_SHIFT) + 1;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
int ll_readpage(struct file *file, struct page *vmpage)
|
|
{
|
|
struct ll_cl_context *lcc;
|
|
int result;
|
|
|
|
lcc = ll_cl_init(file, vmpage, 0);
|
|
if (!IS_ERR(lcc)) {
|
|
struct lu_env *env = lcc->lcc_env;
|
|
struct cl_io *io = lcc->lcc_io;
|
|
struct cl_page *page = lcc->lcc_page;
|
|
|
|
LASSERT(page->cp_type == CPT_CACHEABLE);
|
|
if (likely(!PageUptodate(vmpage))) {
|
|
cl_page_assume(env, io, page);
|
|
result = cl_io_read_page(env, io, page);
|
|
} else {
|
|
/* Page from a non-object file. */
|
|
unlock_page(vmpage);
|
|
result = 0;
|
|
}
|
|
ll_cl_fini(lcc);
|
|
} else {
|
|
unlock_page(vmpage);
|
|
result = PTR_ERR(lcc);
|
|
}
|
|
return result;
|
|
}
|