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/*
*
* Copyright (C) ST-Ericsson SA 2010
*
* Author: Ulf Hansson <ulf.hansson@stericsson.com> for ST-Ericsson
* License terms: GNU General Public License (GPL) version 2
*
* Create partitions for block devices by reading from the kernel
* command line (kernel boot arguments).
*
*/
#include "check.h"
#include "blkdev_parts.h"
static char *cmdline;
/*
* This is the handler for our kernel commandline parameter,
* called from main.c::checksetup().
* Note that we can not yet kmalloc() anything, so we only save
* the commandline for later processing.
*/
static int cmdline_setup(char *s)
{
cmdline = s;
return 1;
}
__setup("blkdevparts=", cmdline_setup);
/* Parse for a matching blkdev-id and return pointer to partdef */
static char *parse_blkdev_id(char *blkdev_name)
{
int blkdev_id_len;
char *p, *blkdev_id;
/* Start parsing for a matching blkdev-id */
p = blkdev_id = cmdline;
while (blkdev_id != NULL) {
/* Find the end of the blkdev-id string */
p = strchr(blkdev_id, ':');
if (p == NULL)
return NULL;
/* Check if we found a matching blkdev-id */
blkdev_id_len = p - blkdev_id;
if (strlen(blkdev_name) == blkdev_id_len) {
if (strncmp(blkdev_name, blkdev_id, blkdev_id_len) == 0)
return p;
}
/* Move to next blkdev-id string if there is one */
blkdev_id = strchr(p, ';');
if (blkdev_id != NULL)
blkdev_id++;
}
return NULL;
}
static int parse_partdef(char **part, struct parsed_partitions *state, int part_nbr)
{
sector_t size, offset;
char *p = *part;
/* Skip the beginning "," or ":" */
p++;
/* Fetch and verify size from partdef */
size = simple_strtoull(p, &p, 10);
if ((size == 0) || (*p != '@'))
return 0;
/* Skip the "@" */
p++;
/* Fetch offset from partdef and check if there are more parts */
offset = simple_strtoull(p, &p, 10);
if (*p == ',')
*part = p;
else
*part = NULL;
/* Add partition to state */
put_partition(state, part_nbr, offset, size);
printk(KERN_INFO "\nPartition: size=%llu, offset=%llu\n",
(unsigned long long) size,
(unsigned long long) offset);
return 1;
}
static int parse_blkdev_parts(char *blkdev_name, struct parsed_partitions *state)
{
char *partdef;
int part_nbr = 0;
/* Find partdef */
partdef = parse_blkdev_id(blkdev_name);
/* Add parts */
while (partdef != NULL) {
/* Find next part and add it to state */
part_nbr++;
if (!parse_partdef(&partdef, state, part_nbr))
return 0;
}
return part_nbr;
}
int blkdev_partition(struct parsed_partitions *state)
{
char blkdev_name[BDEVNAME_SIZE];
/* Check if there are any partitions to handle */
if (cmdline == NULL)
return 0;
/* Get the name of the blockdevice we are operating upon */
if (bdevname(state->bdev, blkdev_name) == NULL) {
printk(KERN_WARNING "Could not get a blkdev name\n");
return 0;
}
/* Parse for partitions and add them to the state */
return parse_blkdev_parts(blkdev_name, state);
}
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