mtd: cmdlinepart: revise error handling

This patch revises and fixes error handling in the command line mtd
partitions parser. Namely:
1. we ignored return code of 'mtdpart_setup_real()'.
2. instead of returning 0 for failure and 1 for success, teach
   'mtdpart_setup_real()' to return real error codes.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index b4faca25cf31..58dd0d0d7383 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -39,11 +39,10 @@
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
-
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
-#include <linux/bootmem.h>
 #include <linux/module.h>
+#include <linux/err.h>
 
 /* error message prefix */
 #define ERRP "mtd: "
@@ -110,7 +109,7 @@ static struct mtd_partition * newpart(char *s,
                 if (size < PAGE_SIZE)
                 {
                         printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
-                        return NULL;
+                        return ERR_PTR(-EINVAL);
                 }
         }
 
@@ -138,7 +137,7 @@ static struct mtd_partition * newpart(char *s,
                 if (!p)
                 {
                         printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
-                        return NULL;
+                        return ERR_PTR(-EINVAL);
                 }
                 name_len = p - name;
                 s = p + 1;
@@ -172,13 +171,13 @@ static struct mtd_partition * newpart(char *s,
                 if (size == SIZE_REMAINING)
                 {
                         printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
-                        return NULL;
+                        return ERR_PTR(-EINVAL);
                 }
                 /* more partitions follow, parse them */
                 parts = newpart(s + 1, &s, num_parts, this_part + 1,
                                 &extra_mem, extra_mem_size);
-                if (!parts)
-                        return NULL;
+                if (IS_ERR(parts))
+                        return parts;
         }
         else
         {       /* this is the last partition: allocate space for all */
@@ -189,7 +188,7 @@ static struct mtd_partition * newpart(char *s,
                              extra_mem_size;
                 parts = kzalloc(alloc_size, GFP_KERNEL);
                 if (!parts)
-                        return NULL;
+                        return ERR_PTR(-ENOMEM);
                 extra_mem = (unsigned char *)(parts + *num_parts);
         }
         /* enter this partition (offset will be calculated later if it is zero at this point) */
@@ -245,7 +244,7 @@ static int mtdpart_setup_real(char *s)
                 if (!(p = strchr(s, ':')))
                 {
                         printk(KERN_ERR ERRP "no mtd-id\n");
-                        return 0;
+                        return -EINVAL;
                 }
                 mtd_id_len = p - mtd_id;
 
@@ -262,7 +261,7 @@ static int mtdpart_setup_real(char *s)
                                 (unsigned char**)&this_mtd, /* out: extra mem */
                                 mtd_id_len + 1 + sizeof(*this_mtd) +
                                 sizeof(void*)-1 /*alignment*/);
-                if(!parts)
+                if (IS_ERR(parts))
                 {
                         /*
                          * An error occurred. We're either:
@@ -271,7 +270,7 @@ static int mtdpart_setup_real(char *s)
                          * Either way, this mtd is hosed and we're
                          * unlikely to succeed in parsing any more
                          */
-                         return 0;
+                         return PTR_ERR(parts);
                  }
 
                 /* align this_mtd */
@@ -299,11 +298,11 @@ static int mtdpart_setup_real(char *s)
                 if (*s != ';')
                 {
                         printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
-                        return 0;
+                        return -EINVAL;
                 }
                 s++;
         }
-        return 1;
+        return 0;
 }
 
 /*
@@ -318,13 +317,16 @@ static int parse_cmdline_partitions(struct mtd_info *master,
                                     struct mtd_part_parser_data *data)
 {
         unsigned long offset;
-        int i;
+        int i, err;
         struct cmdline_mtd_partition *part;
         const char *mtd_id = master->name;
 
         /* parse command line */
-        if (!cmdline_parsed)
-                mtdpart_setup_real(cmdline);
+        if (!cmdline_parsed) {
+                err = mtdpart_setup_real(cmdline);
+                if (err)
+                        return err;
+        }
 
         for(part = partitions; part; part = part->next)
         {