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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 50 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
622 lines
14 KiB
C
622 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Interface to Linux block layer for MTD 'translation layers'.
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*
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* Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/mtd/blktrans.h>
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#include <linux/mtd/mtd.h>
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#include <linux/blkdev.h>
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#include <linux/blk-mq.h>
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#include <linux/blkpg.h>
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#include <linux/spinlock.h>
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#include <linux/hdreg.h>
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#include <linux/mutex.h>
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#include <linux/uaccess.h>
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#include "mtdcore.h"
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static LIST_HEAD(blktrans_majors);
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static DEFINE_MUTEX(blktrans_ref_mutex);
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static void blktrans_dev_release(struct kref *kref)
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{
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struct mtd_blktrans_dev *dev =
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container_of(kref, struct mtd_blktrans_dev, ref);
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dev->disk->private_data = NULL;
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blk_cleanup_queue(dev->rq);
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blk_mq_free_tag_set(dev->tag_set);
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kfree(dev->tag_set);
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put_disk(dev->disk);
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list_del(&dev->list);
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kfree(dev);
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}
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static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk)
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{
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struct mtd_blktrans_dev *dev;
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mutex_lock(&blktrans_ref_mutex);
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dev = disk->private_data;
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if (!dev)
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goto unlock;
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kref_get(&dev->ref);
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unlock:
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mutex_unlock(&blktrans_ref_mutex);
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return dev;
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}
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static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
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{
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mutex_lock(&blktrans_ref_mutex);
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kref_put(&dev->ref, blktrans_dev_release);
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mutex_unlock(&blktrans_ref_mutex);
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}
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static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
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struct mtd_blktrans_dev *dev,
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struct request *req)
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{
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unsigned long block, nsect;
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char *buf;
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block = blk_rq_pos(req) << 9 >> tr->blkshift;
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nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
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if (req_op(req) == REQ_OP_FLUSH) {
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if (tr->flush(dev))
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return BLK_STS_IOERR;
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return BLK_STS_OK;
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}
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if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
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get_capacity(req->rq_disk))
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return BLK_STS_IOERR;
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switch (req_op(req)) {
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case REQ_OP_DISCARD:
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if (tr->discard(dev, block, nsect))
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return BLK_STS_IOERR;
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return BLK_STS_OK;
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case REQ_OP_READ:
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buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
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for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
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if (tr->readsect(dev, block, buf)) {
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kunmap(bio_page(req->bio));
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return BLK_STS_IOERR;
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}
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}
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kunmap(bio_page(req->bio));
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rq_flush_dcache_pages(req);
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return BLK_STS_OK;
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case REQ_OP_WRITE:
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if (!tr->writesect)
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return BLK_STS_IOERR;
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rq_flush_dcache_pages(req);
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buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
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for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
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if (tr->writesect(dev, block, buf)) {
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kunmap(bio_page(req->bio));
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return BLK_STS_IOERR;
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}
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}
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kunmap(bio_page(req->bio));
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return BLK_STS_OK;
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default:
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return BLK_STS_IOERR;
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}
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}
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int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
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{
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return dev->bg_stop;
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}
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EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
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static struct request *mtd_next_request(struct mtd_blktrans_dev *dev)
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{
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struct request *rq;
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rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist);
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if (rq) {
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list_del_init(&rq->queuelist);
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blk_mq_start_request(rq);
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return rq;
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}
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return NULL;
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}
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static void mtd_blktrans_work(struct mtd_blktrans_dev *dev)
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__releases(&dev->queue_lock)
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__acquires(&dev->queue_lock)
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{
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struct mtd_blktrans_ops *tr = dev->tr;
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struct request *req = NULL;
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int background_done = 0;
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while (1) {
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blk_status_t res;
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dev->bg_stop = false;
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if (!req && !(req = mtd_next_request(dev))) {
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if (tr->background && !background_done) {
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spin_unlock_irq(&dev->queue_lock);
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mutex_lock(&dev->lock);
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tr->background(dev);
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mutex_unlock(&dev->lock);
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spin_lock_irq(&dev->queue_lock);
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/*
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* Do background processing just once per idle
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* period.
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*/
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background_done = !dev->bg_stop;
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continue;
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}
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break;
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}
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spin_unlock_irq(&dev->queue_lock);
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mutex_lock(&dev->lock);
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res = do_blktrans_request(dev->tr, dev, req);
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mutex_unlock(&dev->lock);
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if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) {
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__blk_mq_end_request(req, res);
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req = NULL;
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}
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background_done = 0;
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spin_lock_irq(&dev->queue_lock);
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}
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}
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static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx,
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const struct blk_mq_queue_data *bd)
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{
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struct mtd_blktrans_dev *dev;
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dev = hctx->queue->queuedata;
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if (!dev) {
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blk_mq_start_request(bd->rq);
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return BLK_STS_IOERR;
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}
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spin_lock_irq(&dev->queue_lock);
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list_add_tail(&bd->rq->queuelist, &dev->rq_list);
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mtd_blktrans_work(dev);
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spin_unlock_irq(&dev->queue_lock);
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return BLK_STS_OK;
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}
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static int blktrans_open(struct block_device *bdev, fmode_t mode)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = 0;
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if (!dev)
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return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
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mutex_lock(&mtd_table_mutex);
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mutex_lock(&dev->lock);
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if (dev->open)
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goto unlock;
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kref_get(&dev->ref);
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__module_get(dev->tr->owner);
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if (!dev->mtd)
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goto unlock;
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if (dev->tr->open) {
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ret = dev->tr->open(dev);
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if (ret)
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goto error_put;
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}
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ret = __get_mtd_device(dev->mtd);
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if (ret)
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goto error_release;
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dev->file_mode = mode;
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unlock:
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dev->open++;
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mutex_unlock(&dev->lock);
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mutex_unlock(&mtd_table_mutex);
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blktrans_dev_put(dev);
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return ret;
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error_release:
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if (dev->tr->release)
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dev->tr->release(dev);
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error_put:
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module_put(dev->tr->owner);
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kref_put(&dev->ref, blktrans_dev_release);
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mutex_unlock(&dev->lock);
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mutex_unlock(&mtd_table_mutex);
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blktrans_dev_put(dev);
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return ret;
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}
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static void blktrans_release(struct gendisk *disk, fmode_t mode)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
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if (!dev)
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return;
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mutex_lock(&mtd_table_mutex);
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mutex_lock(&dev->lock);
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if (--dev->open)
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goto unlock;
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kref_put(&dev->ref, blktrans_dev_release);
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module_put(dev->tr->owner);
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if (dev->mtd) {
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if (dev->tr->release)
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dev->tr->release(dev);
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__put_mtd_device(dev->mtd);
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}
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unlock:
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mutex_unlock(&dev->lock);
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mutex_unlock(&mtd_table_mutex);
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blktrans_dev_put(dev);
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}
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static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = -ENXIO;
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if (!dev)
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return ret;
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mutex_lock(&dev->lock);
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if (!dev->mtd)
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goto unlock;
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ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
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unlock:
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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}
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static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
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unsigned int cmd, unsigned long arg)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = -ENXIO;
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if (!dev)
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return ret;
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mutex_lock(&dev->lock);
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if (!dev->mtd)
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goto unlock;
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switch (cmd) {
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case BLKFLSBUF:
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ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
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break;
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default:
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ret = -ENOTTY;
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}
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unlock:
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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}
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static const struct block_device_operations mtd_block_ops = {
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.owner = THIS_MODULE,
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.open = blktrans_open,
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.release = blktrans_release,
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.ioctl = blktrans_ioctl,
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.getgeo = blktrans_getgeo,
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};
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static const struct blk_mq_ops mtd_mq_ops = {
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.queue_rq = mtd_queue_rq,
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};
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int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
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{
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struct mtd_blktrans_ops *tr = new->tr;
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struct mtd_blktrans_dev *d;
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int last_devnum = -1;
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struct gendisk *gd;
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int ret;
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if (mutex_trylock(&mtd_table_mutex)) {
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mutex_unlock(&mtd_table_mutex);
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BUG();
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}
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mutex_lock(&blktrans_ref_mutex);
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list_for_each_entry(d, &tr->devs, list) {
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if (new->devnum == -1) {
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/* Use first free number */
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if (d->devnum != last_devnum+1) {
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/* Found a free devnum. Plug it in here */
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new->devnum = last_devnum+1;
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list_add_tail(&new->list, &d->list);
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goto added;
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}
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} else if (d->devnum == new->devnum) {
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/* Required number taken */
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mutex_unlock(&blktrans_ref_mutex);
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return -EBUSY;
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} else if (d->devnum > new->devnum) {
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/* Required number was free */
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list_add_tail(&new->list, &d->list);
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goto added;
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}
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last_devnum = d->devnum;
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}
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ret = -EBUSY;
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if (new->devnum == -1)
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new->devnum = last_devnum+1;
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/* Check that the device and any partitions will get valid
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* minor numbers and that the disk naming code below can cope
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* with this number. */
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if (new->devnum > (MINORMASK >> tr->part_bits) ||
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(tr->part_bits && new->devnum >= 27 * 26)) {
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mutex_unlock(&blktrans_ref_mutex);
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goto error1;
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}
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list_add_tail(&new->list, &tr->devs);
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added:
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mutex_unlock(&blktrans_ref_mutex);
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mutex_init(&new->lock);
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kref_init(&new->ref);
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if (!tr->writesect)
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new->readonly = 1;
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/* Create gendisk */
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ret = -ENOMEM;
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gd = alloc_disk(1 << tr->part_bits);
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if (!gd)
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goto error2;
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new->disk = gd;
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gd->private_data = new;
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gd->major = tr->major;
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gd->first_minor = (new->devnum) << tr->part_bits;
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gd->fops = &mtd_block_ops;
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if (tr->part_bits)
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if (new->devnum < 26)
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%c", tr->name, 'a' + new->devnum);
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else
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%c%c", tr->name,
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'a' - 1 + new->devnum / 26,
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'a' + new->devnum % 26);
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else
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%d", tr->name, new->devnum);
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set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
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/* Create the request queue */
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spin_lock_init(&new->queue_lock);
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INIT_LIST_HEAD(&new->rq_list);
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new->tag_set = kzalloc(sizeof(*new->tag_set), GFP_KERNEL);
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if (!new->tag_set)
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goto error3;
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new->rq = blk_mq_init_sq_queue(new->tag_set, &mtd_mq_ops, 2,
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BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
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if (IS_ERR(new->rq)) {
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ret = PTR_ERR(new->rq);
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new->rq = NULL;
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goto error4;
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}
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if (tr->flush)
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blk_queue_write_cache(new->rq, true, false);
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new->rq->queuedata = new;
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blk_queue_logical_block_size(new->rq, tr->blksize);
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blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
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blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
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if (tr->discard) {
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blk_queue_flag_set(QUEUE_FLAG_DISCARD, new->rq);
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blk_queue_max_discard_sectors(new->rq, UINT_MAX);
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}
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gd->queue = new->rq;
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if (new->readonly)
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set_disk_ro(gd, 1);
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device_add_disk(&new->mtd->dev, gd, NULL);
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if (new->disk_attributes) {
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ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
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new->disk_attributes);
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WARN_ON(ret);
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}
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return 0;
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error4:
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kfree(new->tag_set);
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error3:
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put_disk(new->disk);
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error2:
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list_del(&new->list);
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error1:
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return ret;
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}
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int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
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{
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unsigned long flags;
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if (mutex_trylock(&mtd_table_mutex)) {
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mutex_unlock(&mtd_table_mutex);
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BUG();
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}
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if (old->disk_attributes)
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sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
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old->disk_attributes);
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/* Stop new requests to arrive */
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del_gendisk(old->disk);
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/* Kill current requests */
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spin_lock_irqsave(&old->queue_lock, flags);
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old->rq->queuedata = NULL;
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spin_unlock_irqrestore(&old->queue_lock, flags);
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/* freeze+quiesce queue to ensure all requests are flushed */
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blk_mq_freeze_queue(old->rq);
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blk_mq_quiesce_queue(old->rq);
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blk_mq_unquiesce_queue(old->rq);
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blk_mq_unfreeze_queue(old->rq);
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/* If the device is currently open, tell trans driver to close it,
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then put mtd device, and don't touch it again */
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mutex_lock(&old->lock);
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if (old->open) {
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if (old->tr->release)
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old->tr->release(old);
|
|
__put_mtd_device(old->mtd);
|
|
}
|
|
|
|
old->mtd = NULL;
|
|
|
|
mutex_unlock(&old->lock);
|
|
blktrans_dev_put(old);
|
|
return 0;
|
|
}
|
|
|
|
static void blktrans_notify_remove(struct mtd_info *mtd)
|
|
{
|
|
struct mtd_blktrans_ops *tr;
|
|
struct mtd_blktrans_dev *dev, *next;
|
|
|
|
list_for_each_entry(tr, &blktrans_majors, list)
|
|
list_for_each_entry_safe(dev, next, &tr->devs, list)
|
|
if (dev->mtd == mtd)
|
|
tr->remove_dev(dev);
|
|
}
|
|
|
|
static void blktrans_notify_add(struct mtd_info *mtd)
|
|
{
|
|
struct mtd_blktrans_ops *tr;
|
|
|
|
if (mtd->type == MTD_ABSENT)
|
|
return;
|
|
|
|
list_for_each_entry(tr, &blktrans_majors, list)
|
|
tr->add_mtd(tr, mtd);
|
|
}
|
|
|
|
static struct mtd_notifier blktrans_notifier = {
|
|
.add = blktrans_notify_add,
|
|
.remove = blktrans_notify_remove,
|
|
};
|
|
|
|
int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
|
|
{
|
|
struct mtd_info *mtd;
|
|
int ret;
|
|
|
|
/* Register the notifier if/when the first device type is
|
|
registered, to prevent the link/init ordering from fucking
|
|
us over. */
|
|
if (!blktrans_notifier.list.next)
|
|
register_mtd_user(&blktrans_notifier);
|
|
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
ret = register_blkdev(tr->major, tr->name);
|
|
if (ret < 0) {
|
|
printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
|
|
tr->name, tr->major, ret);
|
|
mutex_unlock(&mtd_table_mutex);
|
|
return ret;
|
|
}
|
|
|
|
if (ret)
|
|
tr->major = ret;
|
|
|
|
tr->blkshift = ffs(tr->blksize) - 1;
|
|
|
|
INIT_LIST_HEAD(&tr->devs);
|
|
list_add(&tr->list, &blktrans_majors);
|
|
|
|
mtd_for_each_device(mtd)
|
|
if (mtd->type != MTD_ABSENT)
|
|
tr->add_mtd(tr, mtd);
|
|
|
|
mutex_unlock(&mtd_table_mutex);
|
|
return 0;
|
|
}
|
|
|
|
int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
|
|
{
|
|
struct mtd_blktrans_dev *dev, *next;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
/* Remove it from the list of active majors */
|
|
list_del(&tr->list);
|
|
|
|
list_for_each_entry_safe(dev, next, &tr->devs, list)
|
|
tr->remove_dev(dev);
|
|
|
|
unregister_blkdev(tr->major, tr->name);
|
|
mutex_unlock(&mtd_table_mutex);
|
|
|
|
BUG_ON(!list_empty(&tr->devs));
|
|
return 0;
|
|
}
|
|
|
|
static void __exit mtd_blktrans_exit(void)
|
|
{
|
|
/* No race here -- if someone's currently in register_mtd_blktrans
|
|
we're screwed anyway. */
|
|
if (blktrans_notifier.list.next)
|
|
unregister_mtd_user(&blktrans_notifier);
|
|
}
|
|
|
|
module_exit(mtd_blktrans_exit);
|
|
|
|
EXPORT_SYMBOL_GPL(register_mtd_blktrans);
|
|
EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
|
|
EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
|
|
EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
|
|
|
|
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
|