865 lines
21 KiB
C
865 lines
21 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) 2007, 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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/*
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* linux/drivers/block/loop.c
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*
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* Written by Theodore Ts'o, 3/29/93
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*
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* Copyright 1993 by Theodore Ts'o. Redistribution of this file is
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* permitted under the GNU General Public License.
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*
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* Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994
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* Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996
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*
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* Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997
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*
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* Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998
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*
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* Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998
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*
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* Loadable modules and other fixes by AK, 1998
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*
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* Maximum number of loop devices now dynamic via max_loop module parameter.
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* Russell Kroll <rkroll@exploits.org> 19990701
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*
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* Maximum number of loop devices when compiled-in now selectable by passing
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* max_loop=<1-255> to the kernel on boot.
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* Erik I. Bols?, <eriki@himolde.no>, Oct 31, 1999
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*
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* Completely rewrite request handling to be make_request_fn style and
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* non blocking, pushing work to a helper thread. Lots of fixes from
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* Al Viro too.
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* Jens Axboe <axboe@suse.de>, Nov 2000
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*
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* Support up to 256 loop devices
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* Heinz Mauelshagen <mge@sistina.com>, Feb 2002
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*
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* Support for falling back on the write file operation when the address space
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* operations prepare_write and/or commit_write are not available on the
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* backing filesystem.
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* Anton Altaparmakov, 16 Feb 2005
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*
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* Still To Fix:
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* - Advisory locking is ignored here.
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* - Should use an own CAP_* category instead of CAP_SYS_ADMIN
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*
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*/
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/major.h>
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#include <linux/wait.h>
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#include <linux/blkdev.h>
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#include <linux/blkpg.h>
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#include <linux/init.h>
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#include <linux/swap.h>
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#include <linux/slab.h>
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#include <linux/suspend.h>
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#include <linux/writeback.h>
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#include <linux/buffer_head.h> /* for invalidate_bdev() */
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#include <linux/completion.h>
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#include <linux/highmem.h>
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#include <linux/gfp.h>
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#include <linux/pagevec.h>
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#include <asm/uaccess.h>
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#include <lustre_lib.h>
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#include <lustre_lite.h>
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#include "llite_internal.h"
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#define LLOOP_MAX_SEGMENTS LNET_MAX_IOV
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/* Possible states of device */
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enum {
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LLOOP_UNBOUND,
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LLOOP_BOUND,
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LLOOP_RUNDOWN,
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};
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struct lloop_device {
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int lo_number;
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int lo_refcnt;
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loff_t lo_offset;
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loff_t lo_sizelimit;
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int lo_flags;
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int (*ioctl)(struct lloop_device *, int cmd,
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unsigned long arg);
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struct file *lo_backing_file;
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struct block_device *lo_device;
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unsigned lo_blocksize;
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int old_gfp_mask;
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spinlock_t lo_lock;
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struct bio *lo_bio;
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struct bio *lo_biotail;
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int lo_state;
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struct semaphore lo_sem;
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struct mutex lo_ctl_mutex;
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atomic_t lo_pending;
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wait_queue_head_t lo_bh_wait;
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struct request_queue *lo_queue;
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const struct lu_env *lo_env;
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struct cl_io lo_io;
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struct ll_dio_pages lo_pvec;
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/* data to handle bio for lustre. */
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struct lo_request_data {
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struct page *lrd_pages[LLOOP_MAX_SEGMENTS];
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loff_t lrd_offsets[LLOOP_MAX_SEGMENTS];
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} lo_requests[1];
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};
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/*
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* Loop flags
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*/
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enum {
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LO_FLAGS_READ_ONLY = 1,
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};
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static int lloop_major;
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#define MAX_LOOP_DEFAULT 16
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static int max_loop = MAX_LOOP_DEFAULT;
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static struct lloop_device *loop_dev;
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static struct gendisk **disks;
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static struct mutex lloop_mutex;
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static void *ll_iocontrol_magic = NULL;
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static loff_t get_loop_size(struct lloop_device *lo, struct file *file)
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{
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loff_t size, offset, loopsize;
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/* Compute loopsize in bytes */
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size = i_size_read(file->f_mapping->host);
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offset = lo->lo_offset;
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loopsize = size - offset;
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if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize)
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loopsize = lo->lo_sizelimit;
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/*
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* Unfortunately, if we want to do I/O on the device,
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* the number of 512-byte sectors has to fit into a sector_t.
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*/
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return loopsize >> 9;
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}
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static int do_bio_lustrebacked(struct lloop_device *lo, struct bio *head)
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{
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const struct lu_env *env = lo->lo_env;
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struct cl_io *io = &lo->lo_io;
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struct inode *inode = lo->lo_backing_file->f_dentry->d_inode;
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struct cl_object *obj = ll_i2info(inode)->lli_clob;
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pgoff_t offset;
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int ret;
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int i;
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int rw;
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obd_count page_count = 0;
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struct bio_vec *bvec;
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struct bio *bio;
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ssize_t bytes;
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struct ll_dio_pages *pvec = &lo->lo_pvec;
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struct page **pages = pvec->ldp_pages;
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loff_t *offsets = pvec->ldp_offsets;
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truncate_inode_pages(inode->i_mapping, 0);
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/* initialize the IO */
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memset(io, 0, sizeof(*io));
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io->ci_obj = obj;
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ret = cl_io_init(env, io, CIT_MISC, obj);
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if (ret)
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return io->ci_result;
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io->ci_lockreq = CILR_NEVER;
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LASSERT(head != NULL);
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rw = head->bi_rw;
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for (bio = head; bio != NULL; bio = bio->bi_next) {
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LASSERT(rw == bio->bi_rw);
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offset = (pgoff_t)(bio->bi_iter.bi_sector << 9) + lo->lo_offset;
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bio_for_each_segment(bvec, bio, i) {
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BUG_ON(bvec->bv_offset != 0);
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BUG_ON(bvec->bv_len != PAGE_CACHE_SIZE);
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pages[page_count] = bvec->bv_page;
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offsets[page_count] = offset;
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page_count++;
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offset += bvec->bv_len;
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}
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LASSERT(page_count <= LLOOP_MAX_SEGMENTS);
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}
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ll_stats_ops_tally(ll_i2sbi(inode),
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(rw == WRITE) ? LPROC_LL_BRW_WRITE : LPROC_LL_BRW_READ,
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page_count);
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pvec->ldp_size = page_count << PAGE_CACHE_SHIFT;
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pvec->ldp_nr = page_count;
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/* FIXME: in ll_direct_rw_pages, it has to allocate many cl_page{}s to
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* write those pages into OST. Even worse case is that more pages
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* would be asked to write out to swap space, and then finally get here
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* again.
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* Unfortunately this is NOT easy to fix.
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* Thoughts on solution:
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* 0. Define a reserved pool for cl_pages, which could be a list of
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* pre-allocated cl_pages;
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* 1. Define a new operation in cl_object_operations{}, says clo_depth,
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* which measures how many layers for this lustre object. Generally
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* speaking, the depth would be 2, one for llite, and one for lovsub.
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* However, for SNS, there will be more since we need additional page
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* to store parity;
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* 2. Reserve the # of (page_count * depth) cl_pages from the reserved
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* pool. Afterwards, the clio would allocate the pages from reserved
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* pool, this guarantees we neeedn't allocate the cl_pages from
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* generic cl_page slab cache.
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* Of course, if there is NOT enough pages in the pool, we might
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* be asked to write less pages once, this purely depends on
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* implementation. Anyway, we should be careful to avoid deadlocking.
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*/
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mutex_lock(&inode->i_mutex);
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bytes = ll_direct_rw_pages(env, io, rw, inode, pvec);
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mutex_unlock(&inode->i_mutex);
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cl_io_fini(env, io);
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return (bytes == pvec->ldp_size) ? 0 : (int)bytes;
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}
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/*
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* Add bio to back of pending list
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*/
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static void loop_add_bio(struct lloop_device *lo, struct bio *bio)
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{
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unsigned long flags;
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spin_lock_irqsave(&lo->lo_lock, flags);
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if (lo->lo_biotail) {
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lo->lo_biotail->bi_next = bio;
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lo->lo_biotail = bio;
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} else
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lo->lo_bio = lo->lo_biotail = bio;
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spin_unlock_irqrestore(&lo->lo_lock, flags);
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atomic_inc(&lo->lo_pending);
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if (waitqueue_active(&lo->lo_bh_wait))
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wake_up(&lo->lo_bh_wait);
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}
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/*
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* Grab first pending buffer
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*/
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static unsigned int loop_get_bio(struct lloop_device *lo, struct bio **req)
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{
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struct bio *first;
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struct bio **bio;
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unsigned int count = 0;
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unsigned int page_count = 0;
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int rw;
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spin_lock_irq(&lo->lo_lock);
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first = lo->lo_bio;
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if (unlikely(first == NULL)) {
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spin_unlock_irq(&lo->lo_lock);
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return 0;
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}
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/* TODO: need to split the bio, too bad. */
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LASSERT(first->bi_vcnt <= LLOOP_MAX_SEGMENTS);
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rw = first->bi_rw;
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bio = &lo->lo_bio;
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while (*bio && (*bio)->bi_rw == rw) {
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CDEBUG(D_INFO, "bio sector %llu size %u count %u vcnt%u \n",
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(unsigned long long)(*bio)->bi_iter.bi_sector,
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(*bio)->bi_iter.bi_size,
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page_count, (*bio)->bi_vcnt);
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if (page_count + (*bio)->bi_vcnt > LLOOP_MAX_SEGMENTS)
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break;
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page_count += (*bio)->bi_vcnt;
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count++;
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bio = &(*bio)->bi_next;
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}
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if (*bio) {
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/* Some of bios can't be mergable. */
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lo->lo_bio = *bio;
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*bio = NULL;
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} else {
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/* Hit the end of queue */
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lo->lo_biotail = NULL;
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lo->lo_bio = NULL;
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}
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*req = first;
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spin_unlock_irq(&lo->lo_lock);
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return count;
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}
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static void loop_make_request(struct request_queue *q, struct bio *old_bio)
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{
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struct lloop_device *lo = q->queuedata;
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int rw = bio_rw(old_bio);
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int inactive;
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if (!lo)
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goto err;
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CDEBUG(D_INFO, "submit bio sector %llu size %u\n",
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(unsigned long long)old_bio->bi_iter.bi_sector,
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old_bio->bi_iter.bi_size);
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spin_lock_irq(&lo->lo_lock);
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inactive = (lo->lo_state != LLOOP_BOUND);
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spin_unlock_irq(&lo->lo_lock);
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if (inactive)
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goto err;
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if (rw == WRITE) {
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if (lo->lo_flags & LO_FLAGS_READ_ONLY)
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goto err;
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} else if (rw == READA) {
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rw = READ;
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} else if (rw != READ) {
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CERROR("lloop: unknown command (%x)\n", rw);
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goto err;
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}
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loop_add_bio(lo, old_bio);
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return;
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err:
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cfs_bio_io_error(old_bio, old_bio->bi_iter.bi_size);
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}
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|
|
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static inline void loop_handle_bio(struct lloop_device *lo, struct bio *bio)
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{
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int ret;
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ret = do_bio_lustrebacked(lo, bio);
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while (bio) {
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struct bio *tmp = bio->bi_next;
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bio->bi_next = NULL;
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cfs_bio_endio(bio, bio->bi_iter.bi_size, ret);
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bio = tmp;
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}
|
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}
|
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|
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static inline int loop_active(struct lloop_device *lo)
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{
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return atomic_read(&lo->lo_pending) ||
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(lo->lo_state == LLOOP_RUNDOWN);
|
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}
|
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|
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/*
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* worker thread that handles reads/writes to file backed loop devices,
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* to avoid blocking in our make_request_fn.
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*/
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static int loop_thread(void *data)
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{
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struct lloop_device *lo = data;
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struct bio *bio;
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unsigned int count;
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unsigned long times = 0;
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unsigned long total_count = 0;
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|
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struct lu_env *env;
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int refcheck;
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int ret = 0;
|
|
|
|
set_user_nice(current, -20);
|
|
|
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lo->lo_state = LLOOP_BOUND;
|
|
|
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env = cl_env_get(&refcheck);
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if (IS_ERR(env))
|
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GOTO(out, ret = PTR_ERR(env));
|
|
|
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lo->lo_env = env;
|
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memset(&lo->lo_pvec, 0, sizeof(lo->lo_pvec));
|
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lo->lo_pvec.ldp_pages = lo->lo_requests[0].lrd_pages;
|
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lo->lo_pvec.ldp_offsets = lo->lo_requests[0].lrd_offsets;
|
|
|
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/*
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* up sem, we are running
|
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*/
|
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up(&lo->lo_sem);
|
|
|
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for (;;) {
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wait_event(lo->lo_bh_wait, loop_active(lo));
|
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if (!atomic_read(&lo->lo_pending)) {
|
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int exiting = 0;
|
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spin_lock_irq(&lo->lo_lock);
|
|
exiting = (lo->lo_state == LLOOP_RUNDOWN);
|
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spin_unlock_irq(&lo->lo_lock);
|
|
if (exiting)
|
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break;
|
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}
|
|
|
|
bio = NULL;
|
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count = loop_get_bio(lo, &bio);
|
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if (!count) {
|
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CWARN("lloop(minor: %d): missing bio\n", lo->lo_number);
|
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continue;
|
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}
|
|
|
|
total_count += count;
|
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if (total_count < count) { /* overflow */
|
|
total_count = count;
|
|
times = 1;
|
|
} else {
|
|
times++;
|
|
}
|
|
if ((times & 127) == 0) {
|
|
CDEBUG(D_INFO, "total: %lu, count: %lu, avg: %lu\n",
|
|
total_count, times, total_count / times);
|
|
}
|
|
|
|
LASSERT(bio != NULL);
|
|
LASSERT(count <= atomic_read(&lo->lo_pending));
|
|
loop_handle_bio(lo, bio);
|
|
atomic_sub(count, &lo->lo_pending);
|
|
}
|
|
cl_env_put(env, &refcheck);
|
|
|
|
out:
|
|
up(&lo->lo_sem);
|
|
return ret;
|
|
}
|
|
|
|
static int loop_set_fd(struct lloop_device *lo, struct file *unused,
|
|
struct block_device *bdev, struct file *file)
|
|
{
|
|
struct inode *inode;
|
|
struct address_space *mapping;
|
|
int lo_flags = 0;
|
|
int error;
|
|
loff_t size;
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
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return -ENODEV;
|
|
|
|
error = -EBUSY;
|
|
if (lo->lo_state != LLOOP_UNBOUND)
|
|
goto out;
|
|
|
|
mapping = file->f_mapping;
|
|
inode = mapping->host;
|
|
|
|
error = -EINVAL;
|
|
if (!S_ISREG(inode->i_mode) || inode->i_sb->s_magic != LL_SUPER_MAGIC)
|
|
goto out;
|
|
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
lo_flags |= LO_FLAGS_READ_ONLY;
|
|
|
|
size = get_loop_size(lo, file);
|
|
|
|
if ((loff_t)(sector_t)size != size) {
|
|
error = -EFBIG;
|
|
goto out;
|
|
}
|
|
|
|
/* remove all pages in cache so as dirty pages not to be existent. */
|
|
truncate_inode_pages(mapping, 0);
|
|
|
|
set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
|
|
|
|
lo->lo_blocksize = PAGE_CACHE_SIZE;
|
|
lo->lo_device = bdev;
|
|
lo->lo_flags = lo_flags;
|
|
lo->lo_backing_file = file;
|
|
lo->ioctl = NULL;
|
|
lo->lo_sizelimit = 0;
|
|
lo->old_gfp_mask = mapping_gfp_mask(mapping);
|
|
mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
|
|
|
|
lo->lo_bio = lo->lo_biotail = NULL;
|
|
|
|
/*
|
|
* set queue make_request_fn, and add limits based on lower level
|
|
* device
|
|
*/
|
|
blk_queue_make_request(lo->lo_queue, loop_make_request);
|
|
lo->lo_queue->queuedata = lo;
|
|
|
|
/* queue parameters */
|
|
CLASSERT(PAGE_CACHE_SIZE < (1 << (sizeof(unsigned short) * 8)));
|
|
blk_queue_logical_block_size(lo->lo_queue,
|
|
(unsigned short)PAGE_CACHE_SIZE);
|
|
blk_queue_max_hw_sectors(lo->lo_queue,
|
|
LLOOP_MAX_SEGMENTS << (PAGE_CACHE_SHIFT - 9));
|
|
blk_queue_max_segments(lo->lo_queue, LLOOP_MAX_SEGMENTS);
|
|
|
|
set_capacity(disks[lo->lo_number], size);
|
|
bd_set_size(bdev, size << 9);
|
|
|
|
set_blocksize(bdev, lo->lo_blocksize);
|
|
|
|
kthread_run(loop_thread, lo, "lloop%d", lo->lo_number);
|
|
down(&lo->lo_sem);
|
|
return 0;
|
|
|
|
out:
|
|
/* This is safe: open() is still holding a reference. */
|
|
module_put(THIS_MODULE);
|
|
return error;
|
|
}
|
|
|
|
static int loop_clr_fd(struct lloop_device *lo, struct block_device *bdev,
|
|
int count)
|
|
{
|
|
struct file *filp = lo->lo_backing_file;
|
|
int gfp = lo->old_gfp_mask;
|
|
|
|
if (lo->lo_state != LLOOP_BOUND)
|
|
return -ENXIO;
|
|
|
|
if (lo->lo_refcnt > count) /* we needed one fd for the ioctl */
|
|
return -EBUSY;
|
|
|
|
if (filp == NULL)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irq(&lo->lo_lock);
|
|
lo->lo_state = LLOOP_RUNDOWN;
|
|
spin_unlock_irq(&lo->lo_lock);
|
|
wake_up(&lo->lo_bh_wait);
|
|
|
|
down(&lo->lo_sem);
|
|
lo->lo_backing_file = NULL;
|
|
lo->ioctl = NULL;
|
|
lo->lo_device = NULL;
|
|
lo->lo_offset = 0;
|
|
lo->lo_sizelimit = 0;
|
|
lo->lo_flags = 0;
|
|
invalidate_bdev(bdev);
|
|
set_capacity(disks[lo->lo_number], 0);
|
|
bd_set_size(bdev, 0);
|
|
mapping_set_gfp_mask(filp->f_mapping, gfp);
|
|
lo->lo_state = LLOOP_UNBOUND;
|
|
fput(filp);
|
|
/* This is safe: open() is still holding a reference. */
|
|
module_put(THIS_MODULE);
|
|
return 0;
|
|
}
|
|
|
|
static int lo_open(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
struct lloop_device *lo = bdev->bd_disk->private_data;
|
|
|
|
mutex_lock(&lo->lo_ctl_mutex);
|
|
lo->lo_refcnt++;
|
|
mutex_unlock(&lo->lo_ctl_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void lo_release(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
struct lloop_device *lo = disk->private_data;
|
|
|
|
mutex_lock(&lo->lo_ctl_mutex);
|
|
--lo->lo_refcnt;
|
|
mutex_unlock(&lo->lo_ctl_mutex);
|
|
}
|
|
|
|
/* lloop device node's ioctl function. */
|
|
static int lo_ioctl(struct block_device *bdev, fmode_t mode,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct lloop_device *lo = bdev->bd_disk->private_data;
|
|
struct inode *inode = NULL;
|
|
int err = 0;
|
|
|
|
mutex_lock(&lloop_mutex);
|
|
switch (cmd) {
|
|
case LL_IOC_LLOOP_DETACH: {
|
|
err = loop_clr_fd(lo, bdev, 2);
|
|
if (err == 0)
|
|
blkdev_put(bdev, 0); /* grabbed in LLOOP_ATTACH */
|
|
break;
|
|
}
|
|
|
|
case LL_IOC_LLOOP_INFO: {
|
|
struct lu_fid fid;
|
|
|
|
LASSERT(lo->lo_backing_file != NULL);
|
|
if (inode == NULL)
|
|
inode = lo->lo_backing_file->f_dentry->d_inode;
|
|
if (lo->lo_state == LLOOP_BOUND)
|
|
fid = ll_i2info(inode)->lli_fid;
|
|
else
|
|
fid_zero(&fid);
|
|
|
|
if (copy_to_user((struct lu_fid *)arg, &fid, sizeof(fid)))
|
|
err = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
mutex_unlock(&lloop_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct block_device_operations lo_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = lo_open,
|
|
.release = lo_release,
|
|
.ioctl = lo_ioctl,
|
|
};
|
|
|
|
/* dynamic iocontrol callback.
|
|
* This callback is registered in lloop_init and will be called by
|
|
* ll_iocontrol_call.
|
|
*
|
|
* This is a llite regular file ioctl function. It takes the responsibility
|
|
* of attaching or detaching a file by a lloop's device numner.
|
|
*/
|
|
static enum llioc_iter lloop_ioctl(struct inode *unused, struct file *file,
|
|
unsigned int cmd, unsigned long arg,
|
|
void *magic, int *rcp)
|
|
{
|
|
struct lloop_device *lo = NULL;
|
|
struct block_device *bdev = NULL;
|
|
int err = 0;
|
|
dev_t dev;
|
|
|
|
if (magic != ll_iocontrol_magic)
|
|
return LLIOC_CONT;
|
|
|
|
if (disks == NULL)
|
|
GOTO(out1, err = -ENODEV);
|
|
|
|
CWARN("Enter llop_ioctl\n");
|
|
|
|
mutex_lock(&lloop_mutex);
|
|
switch (cmd) {
|
|
case LL_IOC_LLOOP_ATTACH: {
|
|
struct lloop_device *lo_free = NULL;
|
|
int i;
|
|
|
|
for (i = 0; i < max_loop; i++, lo = NULL) {
|
|
lo = &loop_dev[i];
|
|
if (lo->lo_state == LLOOP_UNBOUND) {
|
|
if (!lo_free)
|
|
lo_free = lo;
|
|
continue;
|
|
}
|
|
if (lo->lo_backing_file->f_dentry->d_inode ==
|
|
file->f_dentry->d_inode)
|
|
break;
|
|
}
|
|
if (lo || !lo_free)
|
|
GOTO(out, err = -EBUSY);
|
|
|
|
lo = lo_free;
|
|
dev = MKDEV(lloop_major, lo->lo_number);
|
|
|
|
/* quit if the used pointer is writable */
|
|
if (put_user((long)old_encode_dev(dev), (long*)arg))
|
|
GOTO(out, err = -EFAULT);
|
|
|
|
bdev = blkdev_get_by_dev(dev, file->f_mode, NULL);
|
|
if (IS_ERR(bdev))
|
|
GOTO(out, err = PTR_ERR(bdev));
|
|
|
|
get_file(file);
|
|
err = loop_set_fd(lo, NULL, bdev, file);
|
|
if (err) {
|
|
fput(file);
|
|
blkdev_put(bdev, 0);
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
case LL_IOC_LLOOP_DETACH_BYDEV: {
|
|
int minor;
|
|
|
|
dev = old_decode_dev(arg);
|
|
if (MAJOR(dev) != lloop_major)
|
|
GOTO(out, err = -EINVAL);
|
|
|
|
minor = MINOR(dev);
|
|
if (minor > max_loop - 1)
|
|
GOTO(out, err = -EINVAL);
|
|
|
|
lo = &loop_dev[minor];
|
|
if (lo->lo_state != LLOOP_BOUND)
|
|
GOTO(out, err = -EINVAL);
|
|
|
|
bdev = lo->lo_device;
|
|
err = loop_clr_fd(lo, bdev, 1);
|
|
if (err == 0)
|
|
blkdev_put(bdev, 0); /* grabbed in LLOOP_ATTACH */
|
|
|
|
break;
|
|
}
|
|
|
|
default:
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&lloop_mutex);
|
|
out1:
|
|
if (rcp)
|
|
*rcp = err;
|
|
return LLIOC_STOP;
|
|
}
|
|
|
|
static int __init lloop_init(void)
|
|
{
|
|
int i;
|
|
unsigned int cmdlist[] = {
|
|
LL_IOC_LLOOP_ATTACH,
|
|
LL_IOC_LLOOP_DETACH_BYDEV,
|
|
};
|
|
|
|
if (max_loop < 1 || max_loop > 256) {
|
|
max_loop = MAX_LOOP_DEFAULT;
|
|
CWARN("lloop: invalid max_loop (must be between"
|
|
" 1 and 256), using default (%u)\n", max_loop);
|
|
}
|
|
|
|
lloop_major = register_blkdev(0, "lloop");
|
|
if (lloop_major < 0)
|
|
return -EIO;
|
|
|
|
CDEBUG(D_CONFIG, "registered lloop major %d with %u minors\n",
|
|
lloop_major, max_loop);
|
|
|
|
ll_iocontrol_magic = ll_iocontrol_register(lloop_ioctl, 2, cmdlist);
|
|
if (ll_iocontrol_magic == NULL)
|
|
goto out_mem1;
|
|
|
|
OBD_ALLOC_WAIT(loop_dev, max_loop * sizeof(*loop_dev));
|
|
if (!loop_dev)
|
|
goto out_mem1;
|
|
|
|
OBD_ALLOC_WAIT(disks, max_loop * sizeof(*disks));
|
|
if (!disks)
|
|
goto out_mem2;
|
|
|
|
for (i = 0; i < max_loop; i++) {
|
|
disks[i] = alloc_disk(1);
|
|
if (!disks[i])
|
|
goto out_mem3;
|
|
}
|
|
|
|
mutex_init(&lloop_mutex);
|
|
|
|
for (i = 0; i < max_loop; i++) {
|
|
struct lloop_device *lo = &loop_dev[i];
|
|
struct gendisk *disk = disks[i];
|
|
|
|
lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
|
|
if (!lo->lo_queue)
|
|
goto out_mem4;
|
|
|
|
mutex_init(&lo->lo_ctl_mutex);
|
|
sema_init(&lo->lo_sem, 0);
|
|
init_waitqueue_head(&lo->lo_bh_wait);
|
|
lo->lo_number = i;
|
|
spin_lock_init(&lo->lo_lock);
|
|
disk->major = lloop_major;
|
|
disk->first_minor = i;
|
|
disk->fops = &lo_fops;
|
|
sprintf(disk->disk_name, "lloop%d", i);
|
|
disk->private_data = lo;
|
|
disk->queue = lo->lo_queue;
|
|
}
|
|
|
|
/* We cannot fail after we call this, so another loop!*/
|
|
for (i = 0; i < max_loop; i++)
|
|
add_disk(disks[i]);
|
|
return 0;
|
|
|
|
out_mem4:
|
|
while (i--)
|
|
blk_cleanup_queue(loop_dev[i].lo_queue);
|
|
i = max_loop;
|
|
out_mem3:
|
|
while (i--)
|
|
put_disk(disks[i]);
|
|
OBD_FREE(disks, max_loop * sizeof(*disks));
|
|
out_mem2:
|
|
OBD_FREE(loop_dev, max_loop * sizeof(*loop_dev));
|
|
out_mem1:
|
|
unregister_blkdev(lloop_major, "lloop");
|
|
ll_iocontrol_unregister(ll_iocontrol_magic);
|
|
CERROR("lloop: ran out of memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void lloop_exit(void)
|
|
{
|
|
int i;
|
|
|
|
ll_iocontrol_unregister(ll_iocontrol_magic);
|
|
for (i = 0; i < max_loop; i++) {
|
|
del_gendisk(disks[i]);
|
|
blk_cleanup_queue(loop_dev[i].lo_queue);
|
|
put_disk(disks[i]);
|
|
}
|
|
|
|
unregister_blkdev(lloop_major, "lloop");
|
|
|
|
OBD_FREE(disks, max_loop * sizeof(*disks));
|
|
OBD_FREE(loop_dev, max_loop * sizeof(*loop_dev));
|
|
}
|
|
|
|
module_init(lloop_init);
|
|
module_exit(lloop_exit);
|
|
|
|
CFS_MODULE_PARM(max_loop, "i", int, 0444, "maximum of lloop_device");
|
|
MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
|
|
MODULE_DESCRIPTION("Lustre virtual block device");
|
|
MODULE_LICENSE("GPL");
|