1 files changed, 124 insertions, 61 deletions

diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index f8af627f0b98..d3cf05012b46 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -28,19 +28,26 @@
 #include <linux/workqueue.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
 #include <linux/mtd/mtd.h>
 
 #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;
         int nextcount;
 
         void *oops_buf;
+
+        /* writecount and disabling ready are spin lock protected */
+        spinlock_t writecount_lock;
         int ready;
         int writecount;
 } oops_cxt;
@@ -62,10 +69,7 @@ static int mtdoops_erase_block(struct mtd_info *mtd, int offset)
         erase.mtd = mtd;
         erase.callback = mtdoops_erase_callback;
         erase.addr = offset;
-        if (mtd->erasesize < OOPS_PAGE_SIZE)
-                erase.len = OOPS_PAGE_SIZE;
-        else
-                erase.len = mtd->erasesize;
+        erase.len = mtd->erasesize;
         erase.priv = (u_long)&wait_q;
 
         set_current_state(TASK_INTERRUPTIBLE);
@@ -87,7 +91,7 @@ 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;
@@ -103,25 +107,30 @@ static int mtdoops_inc_counter(struct mtdoops_context *cxt)
 
         ret = mtd->read(mtd, cxt->nextpage * OOPS_PAGE_SIZE, 4,
                         &retlen, (u_char *) &count);
-        if ((retlen != 4) || (ret < 0)) {
+        if ((retlen != 4) || ((ret < 0) && (ret != -EUCLEAN))) {
                 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;
 
@@ -136,8 +145,14 @@ static void mtdoops_prepare(struct mtdoops_context *cxt)
                         cxt->nextpage = 0;
         }
 
-        while (mtd->block_isbad &&
-                        mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE)) {
+        while (mtd->block_isbad) {
+                ret = mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
+                if (!ret)
+                        break;
+                if (ret < 0) {
+                        printk(KERN_ERR "mtdoops: block_isbad failed, aborting.\n");
+                        return;
+                }
 badblock:
                 printk(KERN_WARNING "mtdoops: Bad block at %08x\n",
                                 cxt->nextpage * OOPS_PAGE_SIZE);
@@ -154,34 +169,72 @@ badblock:
         for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
                 ret = mtdoops_erase_block(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
 
-        if (ret < 0) {
-                if (mtd->block_markbad)
-                        mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
-                goto badblock;
+        if (ret >= 0) {
+                printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount);
+                cxt->ready = 1;
+                return;
         }
 
-        printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount);
+        if (mtd->block_markbad && (ret == -EIO)) {
+                ret = mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
+                if (ret < 0) {
+                        printk(KERN_ERR "mtdoops: block_markbad failed, aborting.\n");
+                        return;
+                }
+        }
+        goto badblock;
+}
 
-        cxt->ready = 1;
+static void mtdoops_write(struct mtdoops_context *cxt, int panic)
+{
+        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);
+
+        if (panic)
+                ret = mtd->panic_write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,
+                                        OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);
+        else
+                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 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);
 
-        mtdoops_prepare(cxt);
-}
+        mtdoops_write(cxt, 0);
+}                                       
 
-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 page, maxpos = 0;
+        int ret, page, maxpos = 0;
         u32 count, maxcount = 0xffffffff;
         size_t retlen;
 
         for (page = 0; page < cxt->oops_pages; page++) {
-                mtd->read(mtd, page * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count);
+                ret = mtd->read(mtd, page * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count);
+                if ((retlen != 4) || ((ret < 0) && (ret != -EUCLEAN))) {
+                        printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
+                                ", err %d.\n", page * OOPS_PAGE_SIZE, retlen, ret);
+                        continue;
+                }
+
                 if (count == 0xffffffff)
                         continue;
                 if (maxcount == 0xffffffff) {
@@ -205,20 +258,19 @@ 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;
@@ -229,14 +281,18 @@ static void mtdoops_notify_add(struct mtd_info *mtd)
                 return;
         }
 
+        if (mtd->erasesize < OOPS_PAGE_SIZE) {
+                printk(KERN_ERR "Eraseblock size of MTD partition %d too small\n",
+                                mtd->index);
+                return;
+        }
+
         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);
+        printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
 }
 
 static void mtdoops_notify_remove(struct mtd_info *mtd)
@@ -254,31 +310,28 @@ static void mtdoops_console_sync(void)
 {
         struct mtdoops_context *cxt = &oops_cxt;
         struct mtd_info *mtd = cxt->mtd;
-        size_t retlen;
-        int ret;
+        unsigned long flags;
 
-        if (!cxt->ready || !mtd)
+        if (!cxt->ready || !mtd || cxt->writecount == 0)
                 return;
 
-        if (cxt->writecount == 0)
+        /* 
+         *  Once ready is 0 and we've held the lock no further writes to the 
+         *  buffer will happen
+         */
+        spin_lock_irqsave(&cxt->writecount_lock, flags);
+        if (!cxt->ready) {
+                spin_unlock_irqrestore(&cxt->writecount_lock, flags);
                 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);
+        spin_unlock_irqrestore(&cxt->writecount_lock, flags);
 
-        ret = mtdoops_inc_counter(cxt);
-        if (ret == 1)
-                schedule_work(&cxt->work);
+        if (mtd->panic_write && in_interrupt())
+                /* Interrupt context, we're going to panic so try and log */
+                mtdoops_write(cxt, 1);
+        else
+                schedule_work(&cxt->work_write);
 }
 
 static void
@@ -286,7 +339,7 @@ mtdoops_console_write(struct console *co, const char *s, unsigned int count)
 {
         struct mtdoops_context *cxt = co->data;
         struct mtd_info *mtd = cxt->mtd;
-        int i;
+        unsigned long flags;
 
         if (!oops_in_progress) {
                 mtdoops_console_sync();
@@ -296,6 +349,13 @@ mtdoops_console_write(struct console *co, const char *s, unsigned int count)
         if (!cxt->ready || !mtd)
                 return;
 
+        /* Locking on writecount ensures sequential writes to the buffer */
+        spin_lock_irqsave(&cxt->writecount_lock, flags);
+
+        /* Check ready status didn't change whilst waiting for the lock */
+        if (!cxt->ready)
+                return;
+
         if (cxt->writecount == 0) {
                 u32 *stamp = cxt->oops_buf;
                 *stamp = cxt->nextcount;
@@ -305,10 +365,13 @@ mtdoops_console_write(struct console *co, const char *s, unsigned int count)
         if ((count + cxt->writecount) > OOPS_PAGE_SIZE)
                 count = OOPS_PAGE_SIZE - cxt->writecount;
 
-        for (i = 0; i < count; i++, s++)
-                *((char *)(cxt->oops_buf) + cxt->writecount + i) = *s;
+        memcpy(cxt->oops_buf + cxt->writecount, s, count);
+        cxt->writecount += count;
 
-        cxt->writecount = cxt->writecount + count;
+        spin_unlock_irqrestore(&cxt->writecount_lock, flags);
+
+        if (cxt->writecount == OOPS_PAGE_SIZE)
+                mtdoops_console_sync();
 }
 
 static int __init mtdoops_console_setup(struct console *co, char *options)
@@ -334,7 +397,6 @@ static struct console mtdoops_console = {
         .write          = mtdoops_console_write,
         .setup          = mtdoops_console_setup,
         .unblank        = mtdoops_console_sync,
-        .flags          = CON_PRINTBUFFER,
         .index          = -1,
         .data           = &oops_cxt,
 };
@@ -347,11 +409,12 @@ static int __init mtdoops_console_init(void)
         cxt->oops_buf = vmalloc(OOPS_PAGE_SIZE);
 
         if (!cxt->oops_buf) {
-                printk(KERN_ERR "Failed to allocate oops buffer workspace\n");
+                printk(KERN_ERR "Failed to allocate mtdoops buffer workspace\n");
                 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);