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>

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index b4faca2..58dd0d0 100644 (file)
--- 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)
        {