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Commit 6ce0a856 authored by Richard Purdie's avatar Richard Purdie Committed by David Woodhouse
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[MTD] mtdoops: Perform write operations in a workqueue 



Writing to the flash needs to be done in a workqueue. The console
write functions may be called in any context which can lead to
lockups otherwise.

Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent 2986bd2a

drivers/mtd/mtdoops.c

+42 −40
Original line number Diff line number Diff line
@@ -32,9 +32,10 @@ 


#define OOPS_PAGE_SIZE 4096



static struct mtdoops_context {

struct mtdoops_context {

	int mtd_index;

	struct work_struct work;

	struct work_struct work_erase;

	struct work_struct work_write;

	struct mtd_info *mtd;

	int oops_pages;

	int nextpage;
@@ -87,7 +88,7 @@ static int mtdoops_erase_block(struct mtd_info *mtd, int offset) 
	return 0;

}



static int mtdoops_inc_counter(struct mtdoops_context *cxt)

static void mtdoops_inc_counter(struct mtdoops_context *cxt)

{

	struct mtd_info *mtd = cxt->mtd;

	size_t retlen;
@@ -107,21 +108,26 @@ static int mtdoops_inc_counter(struct mtdoops_context *cxt) 
		printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"

				", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE,

				retlen, ret);

		return 1;

		schedule_work(&cxt->work_erase);

		return;

	}



	/* See if we need to erase the next block */

	if (count != 0xffffffff)

		return 1;

	if (count != 0xffffffff) {

		schedule_work(&cxt->work_erase);

		return;

	}



	printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n",

			cxt->nextpage, cxt->nextcount);

	cxt->ready = 1;

	return 0;

}



static void mtdoops_prepare(struct mtdoops_context *cxt)

/* Scheduled work - when we can't proceed without erasing a block */

static void mtdoops_workfunc_erase(struct work_struct *work)

{

	struct mtdoops_context *cxt =

			container_of(work, struct mtdoops_context, work_erase);

	struct mtd_info *mtd = cxt->mtd;

	int i = 0, j, ret, mod;
@@ -176,15 +182,31 @@ badblock: 
	goto badblock;

}



static void mtdoops_workfunc(struct work_struct *work)

static void mtdoops_workfunc_write(struct work_struct *work)

{

	struct mtdoops_context *cxt =

			container_of(work, struct mtdoops_context, work);

			container_of(work, struct mtdoops_context, work_write);

	struct mtd_info *mtd = cxt->mtd;

	size_t retlen;

	int ret;



	if (cxt->writecount < OOPS_PAGE_SIZE)

		memset(cxt->oops_buf + cxt->writecount, 0xff,

					OOPS_PAGE_SIZE - cxt->writecount);



	ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,

					OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);



	cxt->writecount = 0;



	if ((retlen != OOPS_PAGE_SIZE) || (ret < 0))

		printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n",

			cxt->nextpage * OOPS_PAGE_SIZE, retlen,	OOPS_PAGE_SIZE, ret);



	mtdoops_prepare(cxt);

	mtdoops_inc_counter(cxt);

}					



static int find_next_position(struct mtdoops_context *cxt)

static void find_next_position(struct mtdoops_context *cxt)

{

	struct mtd_info *mtd = cxt->mtd;

	int ret, page, maxpos = 0;
@@ -222,20 +244,19 @@ static int find_next_position(struct mtdoops_context *cxt) 
		cxt->ready = 1;

		printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n",

				cxt->nextpage, cxt->nextcount);

		return 0;

		return;

	}



	cxt->nextpage = maxpos;

	cxt->nextcount = maxcount;



	return mtdoops_inc_counter(cxt);

	mtdoops_inc_counter(cxt);

}





static void mtdoops_notify_add(struct mtd_info *mtd)

{

	struct mtdoops_context *cxt = &oops_cxt;

	int ret;



	if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)

		return;
@@ -249,9 +270,7 @@ static void mtdoops_notify_add(struct mtd_info *mtd) 
	cxt->mtd = mtd;

	cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE;



	ret = find_next_position(cxt);

	if (ret == 1)

		mtdoops_prepare(cxt);

	find_next_position(cxt);



	printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index);

}
@@ -271,31 +290,13 @@ static void mtdoops_console_sync(void) 
{

	struct mtdoops_context *cxt = &oops_cxt;

	struct mtd_info *mtd = cxt->mtd;

	size_t retlen;

	int ret;



	if (!cxt->ready || !mtd)

	if (!cxt->ready || !mtd || cxt->writecount == 0)

		return;



	if (cxt->writecount == 0)

		return;



	if (cxt->writecount < OOPS_PAGE_SIZE)

		memset(cxt->oops_buf + cxt->writecount, 0xff,

					OOPS_PAGE_SIZE - cxt->writecount);



	ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,

					OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);

	cxt->ready = 0;

	cxt->writecount = 0;



	if ((retlen != OOPS_PAGE_SIZE) || (ret < 0))

		printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n",

			cxt->nextpage * OOPS_PAGE_SIZE, retlen,	OOPS_PAGE_SIZE, ret);



	ret = mtdoops_inc_counter(cxt);

	if (ret == 1)

		schedule_work(&cxt->work);

	schedule_work(&cxt->work_write);

}



static void
@@ -365,7 +366,8 @@ static int __init mtdoops_console_init(void) 
		return -ENOMEM;

	}



	INIT_WORK(&cxt->work, mtdoops_workfunc);

	INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);

	INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);



	register_console(&mtdoops_console);

	register_mtd_user(&mtdoops_notifier);