iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

UBI: add reboot notifier

Browse Source 
Terminate the UBI background thread prior to restarting the system.

[Artem: amended comments a little]

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Kevin Cernekee 2009-06-09 10:59:19 -07:00 committed by Artem Bityutskiy
parent 6b5c94c6b4
commit d9dd0887cc
2 changed files with 38 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
drivers/mtd/ubi/build.c
View File

@ -41,6 +41,7 @@
#include <linux/miscdevice.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include <linux/reboot.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
@ -822,6 +823,34 @@ static int autoresize(struct ubi_device *ubi, int vol_id)
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.
* @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);
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_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
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
* prevent it from doing anything on this device while we are freeing.
*/
unregister_reboot_notifier(&ubi->reboot_notifier);
if (ubi->bgt_thread)
kthread_stop(ubi->bgt_thread);

4
drivers/mtd/ubi/ubi.h
View File

@ -36,9 +36,9 @@
#include <linux/device.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/notifier.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/ubi.h>
#include <linux/notifier.h>
#include "ubi-media.h"
#include "scan.h"
@ -348,6 +348,7 @@ struct ubi_wl_entry;
* @bgt_thread: background thread description object
* @thread_enabled: if the background thread is enabled
* @bgt_name: background thread name
* @reboot_notifier: notifier to terminate background thread before rebooting
*
* @flash_size: underlying MTD device size (in bytes)
* @peb_count: count of physical eraseblocks on the MTD device
@ -431,6 +432,7 @@ struct ubi_device {
struct task_struct *bgt_thread;
int thread_enabled;
char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
struct notifier_block reboot_notifier;
/* I/O sub-system's stuff */
long long flash_size;