1 files changed, 63 insertions, 30 deletions

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index ede3561be870..401c6a294baa 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -18,6 +18,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/buffer_head.h>
 #include <linux/mutex.h>
+#include <linux/mount.h>
 
 #define VERSION "$Revision: 1.30 $"
 
@@ -236,6 +237,8 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
         }
         return 0;
 }
+
+
 static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
                 size_t *retlen, const u_char *buf)
 {
@@ -299,6 +302,19 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
 
         /* Get a handle on the device */
         bdev = open_bdev_excl(devname, O_RDWR, NULL);
+#ifndef MODULE
+        if (IS_ERR(bdev)) {
+
+                /* We might not have rootfs mounted at this point. Try
+                   to resolve the device name by other means. */
+
+                dev_t dev = name_to_dev_t(devname);
+                if (dev != 0) {
+                        bdev = open_by_devnum(dev, FMODE_WRITE | FMODE_READ);
+                }
+        }
+#endif
+
         if (IS_ERR(bdev)) {
                 ERROR("error: cannot open device %s", devname);
                 goto devinit_err;
@@ -393,26 +409,6 @@ static int parse_num(size_t *num, const char *token)
 }
 
 
-static int parse_name(char **pname, const char *token, size_t limit)
-{
-        size_t len;
-        char *name;
-
-        len = strlen(token) + 1;
-        if (len > limit)
-                return -ENOSPC;
-
-        name = kmalloc(len, GFP_KERNEL);
-        if (!name)
-                return -ENOMEM;
-
-        strcpy(name, token);
-
-        *pname = name;
-        return 0;
-}
-
-
 static inline void kill_final_newline(char *str)
 {
         char *newline = strrchr(str, '\n');
@@ -426,9 +422,15 @@ static inline void kill_final_newline(char *str)
         return 0;                               \
 } while (0)
 
-static int block2mtd_setup(const char *val, struct kernel_param *kp)
+#ifndef MODULE
+static int block2mtd_init_called = 0;
+static __initdata char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
+#endif
+
+
+static int block2mtd_setup2(const char *val)
 {
-        char buf[80+12]; /* 80 for device, 12 for erase size */
+        char buf[80 + 12]; /* 80 for device, 12 for erase size */
         char *str = buf;
         char *token[2];
         char *name;
@@ -450,13 +452,9 @@ static int block2mtd_setup(const char *val, struct kernel_param *kp)
         if (!token[0])
                 parse_err("no argument");
 
-        ret = parse_name(&name, token[0], 80);
-        if (ret == -ENOMEM)
-                parse_err("out of memory");
-        if (ret == -ENOSPC)
-                parse_err("name too long");
-        if (ret)
-                return 0;
+        name = token[0];
+        if (strlen(name) + 1 > 80)
+                parse_err("device name too long");
 
         if (token[1]) {
                 ret = parse_num(&erase_size, token[1]);
@@ -472,13 +470,48 @@ static int block2mtd_setup(const char *val, struct kernel_param *kp)
 }
 
 
+static int block2mtd_setup(const char *val, struct kernel_param *kp)
+{
+#ifdef MODULE
+        return block2mtd_setup2(val);
+#else
+        /* If more parameters are later passed in via
+           /sys/module/block2mtd/parameters/block2mtd
+           and block2mtd_init() has already been called,
+           we can parse the argument now. */
+
+        if (block2mtd_init_called)
+                return block2mtd_setup2(val);
+
+        /* During early boot stage, we only save the parameters
+           here. We must parse them later: if the param passed
+           from kernel boot command line, block2mtd_setup() is
+           called so early that it is not possible to resolve
+           the device (even kmalloc() fails). Deter that work to
+           block2mtd_setup2(). */
+
+        strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
+
+        return 0;
+#endif
+}
+
+
 module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
 MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
 
 static int __init block2mtd_init(void)
 {
+        int ret = 0;
         INFO("version " VERSION);
-        return 0;
+
+#ifndef MODULE
+        if (strlen(block2mtd_paramline))
+                ret = block2mtd_setup2(block2mtd_paramline);
+        block2mtd_init_called = 1;
+#endif
+
+        return ret;
 }