597842aef6
Change-Id: Ia97972540645d4b40cffaafd92189546a7be2805 Signed-off-by: Pranaya Deomani <pranayadeomani@protonmail.com>
122 lines
3.2 KiB
C
Executable File
122 lines
3.2 KiB
C
Executable File
/***********************************************************
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** Copyright (C), 2008-2019, OPPO Mobile Comm Corp., Ltd.
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** VENDOR_EDIT
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** File: - panic_flush.c
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** Description: code to flush device cache in panic
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**
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** Version: 1.0
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** Date : 2019/08/27
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** Author: yanwu@TECH.Storage.FS, add code to flush device cache in panic
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**
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** ------------------ Revision History:------------------------
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** <author> <data> <version > <desc>
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** yanwu 2019/08/27 1.0 add the file
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****************************************************************/
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#define DEBUG
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#include <linux/wait.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/blkdev.h>
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#include <linux/kthread.h>
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#define PANIC_FLUSH_POLL_MS (10)
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struct panic_flush_control {
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struct task_struct *flush_thread;
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wait_queue_head_t flush_wq;
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atomic_t flush_issuing;
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atomic_t flush_issued;
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};
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static struct panic_flush_control *pfc;
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static void panic_issue_flush(struct super_block *sb ,void *arg)
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{
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int ret = -1;
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int *flush_count = (int *)arg;
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if (!(sb->s_flags & MS_RDONLY) && NULL != sb->s_bdev) {
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ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
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}
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if (!ret) {
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(*flush_count)++;
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pr_emerg("blkdev_issue_flush before panic return %d\n", *flush_count);
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}
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}
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static int panic_flush_thread(void *data)
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{
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int flush_count = 0;
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repeat:
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if (kthread_should_stop())
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return 0;
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wait_event(pfc->flush_wq, kthread_should_stop() || atomic_read(&pfc->flush_issuing) > 0);
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if (atomic_read(&pfc->flush_issuing) > 0) {
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iterate_supers(panic_issue_flush, &flush_count);
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pr_emerg("Up to now, total %d panic_issue_flush_count\n", flush_count);
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atomic_inc(&pfc->flush_issued);
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atomic_dec(&pfc->flush_issuing);
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}
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goto repeat;
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}
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extern int sysctl_ext4_fsync_enable;
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int panic_flush_device_cache(int timeout)
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{
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pr_emerg("%s\n", __func__);
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if (!pfc || !sysctl_ext4_fsync_enable) {
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pr_emerg("%s: skip flush device cache\n", __func__);
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return timeout;
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}
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if (atomic_inc_return(&pfc->flush_issuing) == 1 &&
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waitqueue_active(&pfc->flush_wq)) {
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pr_emerg("%s: flush device cache\n", __func__);
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atomic_set(&pfc->flush_issued, 0);
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wake_up(&pfc->flush_wq);
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while (timeout > 0 && atomic_read(&pfc->flush_issued) == 0) {
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mdelay(PANIC_FLUSH_POLL_MS);
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timeout -= PANIC_FLUSH_POLL_MS;
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}
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pr_emerg("%s: remaining timeout = %d\n", __func__, timeout);
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}
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return timeout;
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}
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static int __init create_panic_flush_control(void)
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{
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int err = 0;
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pr_debug("%s\n", __func__);
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pfc = kzalloc(sizeof(*pfc), GFP_KERNEL);
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if (!pfc) {
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pr_err("%s: fail to allocate memory\n", __func__);
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return -ENOMEM;
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}
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init_waitqueue_head(&pfc->flush_wq);
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atomic_set(&pfc->flush_issuing, 0);
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atomic_set(&pfc->flush_issued, 0);
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pfc->flush_thread = kthread_run(panic_flush_thread, pfc, "panic_flush");
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if (IS_ERR(pfc->flush_thread)) {
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err = PTR_ERR(pfc->flush_thread);
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kfree(pfc);
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pfc = NULL;
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}
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return err;
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}
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static void __exit destroy_panic_flush_control(void)
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{
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pr_debug("%s\n", __func__);
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if (pfc && pfc->flush_thread) {
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pr_debug("%s: stop panic_flush thread\n", __func__);
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kthread_stop(pfc->flush_thread);
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kfree(pfc);
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pfc = NULL;
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}
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}
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module_init(create_panic_flush_control);
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module_exit(destroy_panic_flush_control);
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MODULE_DESCRIPTION("OPPO panic flush control");
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MODULE_LICENSE("GPL v2");
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