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Commit d9dd0887 authored by Kevin Cernekee's avatar Kevin Cernekee Committed by Artem Bityutskiy
Browse files

UBI: add reboot notifier 



Terminate the UBI background thread prior to restarting the system.

[Artem: amended comments a little]

Signed-off-by: default avatarKevin Cernekee <kpc.mtd@gmail.com>
Tested-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 6b5c94c6

drivers/mtd/ubi/build.c

+35 −0
Original line number Original line Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/miscdevice.h>

#include <linux/miscdevice.h>

#include <linux/log2.h>

#include <linux/log2.h>

#include <linux/kthread.h>

#include <linux/kthread.h>

#include <linux/reboot.h>

#include "ubi.h"

#include "ubi.h"





/* Maximum length of the 'mtd=' parameter */

/* Maximum length of the 'mtd=' parameter */
@@ -822,6 +823,34 @@ static int autoresize(struct ubi_device *ubi, int vol_id) 
	return 0;

	return 0;

}

}





/**

 * ubi_reboot_notifier - halt UBI transactions immediately prior to a reboot.

 * @n: reboot notifier object

 * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF

 * @cmd: pointer to command string for RESTART2

 *

 * This function stops the UBI background thread so that the flash device

 * remains quiescent when Linux restarts the system. Any queued work will be

 * discarded, but this function will block until do_work() finishes if an

 * operation is already in progress.

 *

 * This function solves a real-life problem observed on NOR flashes when an

 * PEB erase operation starts, then the system is rebooted before the erase is

 * finishes, and the boot loader gets confused and dies. So we prefer to finish

 * the ongoing operation before rebooting.

 */

static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state,

			       void *cmd)

{

	struct ubi_device *ubi;



	ubi = container_of(n, struct ubi_device, reboot_notifier);

	if (ubi->bgt_thread)

		kthread_stop(ubi->bgt_thread);

	ubi_sync(ubi->ubi_num);

	return NOTIFY_DONE;

}



/**

/**

 * ubi_attach_mtd_dev - attach an MTD device.

 * ubi_attach_mtd_dev - attach an MTD device.

 * @mtd: MTD device description object

 * @mtd: MTD device description object
@@ -978,6 +1007,11 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) 
	wake_up_process(ubi->bgt_thread);

	wake_up_process(ubi->bgt_thread);

	spin_unlock(&ubi->wl_lock);

	spin_unlock(&ubi->wl_lock);





	/* Flash device priority is 0 - UBI needs to shut down first */

	ubi->reboot_notifier.priority = 1;

	ubi->reboot_notifier.notifier_call = ubi_reboot_notifier;

	register_reboot_notifier(&ubi->reboot_notifier);



	ubi_devices[ubi_num] = ubi;

	ubi_devices[ubi_num] = ubi;

	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);

	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);

	return ubi_num;

	return ubi_num;
@@ -1049,6 +1083,7 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) 
	 * Before freeing anything, we have to stop the background thread to

	 * Before freeing anything, we have to stop the background thread to

	 * prevent it from doing anything on this device while we are freeing.

	 * prevent it from doing anything on this device while we are freeing.

	 */

	 */

	unregister_reboot_notifier(&ubi->reboot_notifier);

	if (ubi->bgt_thread)

	if (ubi->bgt_thread)

		kthread_stop(ubi->bgt_thread);

		kthread_stop(ubi->bgt_thread);

drivers/mtd/ubi/ubi.h

+3 −1
Original line number Original line Diff line number Diff line
@@ -36,9 +36,9 @@ 
#include <linux/device.h>

#include <linux/device.h>

#include <linux/string.h>

#include <linux/string.h>

#include <linux/vmalloc.h>

#include <linux/vmalloc.h>

#include <linux/notifier.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/ubi.h>

#include <linux/mtd/ubi.h>

#include <linux/notifier.h>





#include "ubi-media.h"

#include "ubi-media.h"

#include "scan.h"

#include "scan.h"
@@ -348,6 +348,7 @@ struct ubi_wl_entry; 
 * @bgt_thread: background thread description object

 * @bgt_thread: background thread description object

 * @thread_enabled: if the background thread is enabled

 * @thread_enabled: if the background thread is enabled

 * @bgt_name: background thread name

 * @bgt_name: background thread name

 * @reboot_notifier: notifier to terminate background thread before rebooting

 *

 *

 * @flash_size: underlying MTD device size (in bytes)

 * @flash_size: underlying MTD device size (in bytes)

 * @peb_count: count of physical eraseblocks on the MTD device

 * @peb_count: count of physical eraseblocks on the MTD device
@@ -431,6 +432,7 @@ struct ubi_device { 
	struct task_struct *bgt_thread;

	struct task_struct *bgt_thread;

	int thread_enabled;

	int thread_enabled;

	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];

	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];

	struct notifier_block reboot_notifier;





	/* I/O sub-system's stuff */

	/* I/O sub-system's stuff */

	long long flash_size;

	long long flash_size;