diff options
| -rw-r--r-- | drivers/mtd/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/mtd/mtdcore.c | 52 | ||||
| -rw-r--r-- | drivers/mtd/mtdpart.c | 18 |
3 files changed, 62 insertions, 21 deletions
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig index 71fea89..a03ad29 100644 --- a/drivers/mtd/Kconfig +++ b/drivers/mtd/Kconfig @@ -309,6 +309,19 @@ config MTD_SWAP The driver provides wear leveling by storing erase counter into the OOB. +config MTD_PARTITIONED_MASTER + bool "Retain master device when partitioned" + default n + depends on MTD + help + For historical reasons, by default, either a master is present or + several partitions are present, but not both. The concern was that + data listed in multiple partitions was dangerous; however, SCSI does + this and it is frequently useful for applications. This config option + leaves the master in even if the device is partitioned. It also makes + the parent of the partition device be the master device, rather than + what lies behind the master. + source "drivers/mtd/chips/Kconfig" source "drivers/mtd/maps/Kconfig" diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 11883bd..d172195 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -38,6 +38,7 @@ #include <linux/gfp.h> #include <linux/slab.h> #include <linux/reboot.h> +#include <linux/kconfig.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> @@ -501,6 +502,29 @@ out_error: return ret; } +static int mtd_add_device_partitions(struct mtd_info *mtd, + struct mtd_partition *real_parts, + int nbparts) +{ + int ret; + + if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { + ret = add_mtd_device(mtd); + if (ret == 1) + return -ENODEV; + } + + if (nbparts > 0) { + ret = add_mtd_partitions(mtd, real_parts, nbparts); + if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) + del_mtd_device(mtd); + return ret; + } + + return 0; +} + + /** * mtd_device_parse_register - parse partitions and register an MTD device. * @@ -523,7 +547,8 @@ out_error: * found this functions tries to fallback to information specified in * @parts/@nr_parts. * * If any partitioning info was found, this function registers the found - * partitions. + * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device + * as a whole is registered first. * * If no partitions were found this function just registers the MTD device * @mtd and exits. * @@ -534,27 +559,21 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, const struct mtd_partition *parts, int nr_parts) { - int err; - struct mtd_partition *real_parts; + int ret; + struct mtd_partition *real_parts = NULL; - err = parse_mtd_partitions(mtd, types, &real_parts, parser_data); - if (err <= 0 && nr_parts && parts) { + ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data); + if (ret <= 0 && nr_parts && parts) { real_parts = kmemdup(parts, sizeof(*parts) * nr_parts, GFP_KERNEL); if (!real_parts) - err = -ENOMEM; + ret = -ENOMEM; else - err = nr_parts; + ret = nr_parts; } - if (err > 0) { - err = add_mtd_partitions(mtd, real_parts, err); - kfree(real_parts); - } else if (err == 0) { - err = add_mtd_device(mtd); - if (err == 1) - err = -ENODEV; - } + if (ret >= 0) + ret = mtd_add_device_partitions(mtd, real_parts, ret); /* * FIXME: some drivers unfortunately call this function more than once. @@ -569,7 +588,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, register_reboot_notifier(&mtd->reboot_notifier); } - return err; + kfree(real_parts); + return ret; } EXPORT_SYMBOL_GPL(mtd_device_parse_register); diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index e779de3..a19ec5a 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -30,6 +30,7 @@ #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/err.h> +#include <linux/kconfig.h> #include "mtdcore.h" @@ -379,10 +380,17 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, slave->mtd.name = name; slave->mtd.owner = master->owner; - /* NOTE: we don't arrange MTDs as a tree; it'd be error-prone - * to have the same data be in two different partitions. + /* NOTE: Historically, we didn't arrange MTDs as a tree out of + * concern for showing the same data in multiple partitions. + * However, it is very useful to have the master node present, + * so the MTD_PARTITIONED_MASTER option allows that. The master + * will have device nodes etc only if this is set, so make the + * parent conditional on that option. Note, this is a way to + * distinguish between the master and the partition in sysfs. */ - slave->mtd.dev.parent = master->dev.parent; + slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ? + &master->dev : + master->dev.parent; slave->mtd._read = part_read; slave->mtd._write = part_write; @@ -631,8 +639,8 @@ EXPORT_SYMBOL_GPL(mtd_del_partition); * and registers slave MTD objects which are bound to the master according to * the partition definitions. * - * We don't register the master, or expect the caller to have done so, - * for reasons of data integrity. + * For historical reasons, this function's caller only registers the master + * if the MTD_PARTITIONED_MASTER config option is set. */ int add_mtd_partitions(struct mtd_info *master, |