Commit 6ce0a856 authored by Richard Purdie's avatar Richard Purdie Committed by David Woodhouse

[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
...@@ -32,9 +32,10 @@ ...@@ -32,9 +32,10 @@
#define OOPS_PAGE_SIZE 4096 #define OOPS_PAGE_SIZE 4096
static struct mtdoops_context { struct mtdoops_context {
int mtd_index; int mtd_index;
struct work_struct work; struct work_struct work_erase;
struct work_struct work_write;
struct mtd_info *mtd; struct mtd_info *mtd;
int oops_pages; int oops_pages;
int nextpage; int nextpage;
...@@ -87,7 +88,7 @@ static int mtdoops_erase_block(struct mtd_info *mtd, int offset) ...@@ -87,7 +88,7 @@ static int mtdoops_erase_block(struct mtd_info *mtd, int offset)
return 0; 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; struct mtd_info *mtd = cxt->mtd;
size_t retlen; size_t retlen;
...@@ -107,21 +108,26 @@ static int mtdoops_inc_counter(struct mtdoops_context *cxt) ...@@ -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)" printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE, ", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE,
retlen, ret); retlen, ret);
return 1; schedule_work(&cxt->work_erase);
return;
} }
/* See if we need to erase the next block */ /* See if we need to erase the next block */
if (count != 0xffffffff) if (count != 0xffffffff) {
return 1; schedule_work(&cxt->work_erase);
return;
}
printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n", printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n",
cxt->nextpage, cxt->nextcount); cxt->nextpage, cxt->nextcount);
cxt->ready = 1; 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; struct mtd_info *mtd = cxt->mtd;
int i = 0, j, ret, mod; int i = 0, j, ret, mod;
...@@ -176,15 +182,31 @@ badblock: ...@@ -176,15 +182,31 @@ badblock:
goto badblock; goto badblock;
} }
static void mtdoops_workfunc(struct work_struct *work) static void mtdoops_workfunc_write(struct work_struct *work)
{ {
struct mtdoops_context *cxt = 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;
mtdoops_prepare(cxt); 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_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; struct mtd_info *mtd = cxt->mtd;
int ret, page, maxpos = 0; int ret, page, maxpos = 0;
...@@ -222,20 +244,19 @@ static int find_next_position(struct mtdoops_context *cxt) ...@@ -222,20 +244,19 @@ static int find_next_position(struct mtdoops_context *cxt)
cxt->ready = 1; cxt->ready = 1;
printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n", printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n",
cxt->nextpage, cxt->nextcount); cxt->nextpage, cxt->nextcount);
return 0; return;
} }
cxt->nextpage = maxpos; cxt->nextpage = maxpos;
cxt->nextcount = maxcount; cxt->nextcount = maxcount;
return mtdoops_inc_counter(cxt); mtdoops_inc_counter(cxt);
} }
static void mtdoops_notify_add(struct mtd_info *mtd) static void mtdoops_notify_add(struct mtd_info *mtd)
{ {
struct mtdoops_context *cxt = &oops_cxt; struct mtdoops_context *cxt = &oops_cxt;
int ret;
if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0) if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
return; return;
...@@ -249,9 +270,7 @@ static void mtdoops_notify_add(struct mtd_info *mtd) ...@@ -249,9 +270,7 @@ static void mtdoops_notify_add(struct mtd_info *mtd)
cxt->mtd = mtd; cxt->mtd = mtd;
cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE; cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE;
ret = find_next_position(cxt); find_next_position(cxt);
if (ret == 1)
mtdoops_prepare(cxt);
printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index); printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index);
} }
...@@ -271,31 +290,13 @@ static void mtdoops_console_sync(void) ...@@ -271,31 +290,13 @@ static void mtdoops_console_sync(void)
{ {
struct mtdoops_context *cxt = &oops_cxt; struct mtdoops_context *cxt = &oops_cxt;
struct mtd_info *mtd = cxt->mtd; struct mtd_info *mtd = cxt->mtd;
size_t retlen;
int ret;
if (!cxt->ready || !mtd) if (!cxt->ready || !mtd || cxt->writecount == 0)
return; 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->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); schedule_work(&cxt->work_write);
if (ret == 1)
schedule_work(&cxt->work);
} }
static void static void
...@@ -365,7 +366,8 @@ static int __init mtdoops_console_init(void) ...@@ -365,7 +366,8 @@ static int __init mtdoops_console_init(void)
return -ENOMEM; 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_console(&mtdoops_console);
register_mtd_user(&mtdoops_notifier); register_mtd_user(&mtdoops_notifier);
......
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