Messages in this thread Patch in this message |  | | | From | Kevin Cernekee <> | | Date | Tue, 9 Jun 2009 10:59:19 -0700 | | Subject | [PATCHv2] MTD: Add UBI reboot notifier |
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Terminate the UBI background thread prior to restarting the system.
Changes from v1:
Add ubi_sync() at the end, to make sure the underlying MTD device has synchronized its buffers.
Clean up comments and formatting.
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> --- drivers/mtd/ubi/build.c | 30 ++++++++++++++++++++++++++++++ drivers/mtd/ubi/ubi.h | 3 +++ 2 files changed, 33 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 4048db8..18b42c9 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -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 */ @@ -726,6 +727,29 @@ static int autoresize(struct ubi_device *ubi, int vol_id) } /** + * 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. + */ +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 * @ubi_num: number to assign to the new UBI device @@ -876,6 +900,11 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) ubi->thread_enabled = 1; wake_up_process(ubi->bgt_thread); + /* 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; return ubi_num; @@ -945,6 +974,7 @@ 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); diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index c055511..c8fab4a 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -36,6 +36,7 @@ #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> @@ -339,6 +340,7 @@ 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 @@ -420,6 +422,7 @@ 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; -- 1.6.3.1
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