From 7b09acdcb944a9be6acc38ab1aa8a0ffd08871c1 Mon Sep 17 00:00:00 2001 From: Joachim Wiberg Date: Sat, 9 Oct 2021 08:09:55 +0200 Subject: [PATCH] mtd: block2mtd: add support for an optional custom MTD label This patch adds support for an optional MTD label for mtd2block emulated MTD devices. Useful when, e.g., testing device images using Qemu. The following line in /etc/fstab can then be used to mount a file system regardless if running on an embedded system, or emulated with block2mtd: mtd:Config /mnt jffs2 noatime,nodiratime 0 0 Kernel command line syntax in the emulated case: block2mtd.block2mtd=/dev/sda,,Config Notice the ',,' it is the optional erase_size, which like before this patch, defaults to PAGE_SIZE when omitted. Hence the strlen() check. Signed-off-by: Joachim Wiberg Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20211009060955.552636-3-troglobit@gmail.com --- drivers/mtd/devices/block2mtd.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index 6c2871788d59..40d7211485da 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -32,7 +32,7 @@ #include /* Maximum number of comma-separated items in the 'block2mtd=' parameter */ -#define BLOCK2MTD_PARAM_MAX_COUNT 2 +#define BLOCK2MTD_PARAM_MAX_COUNT 3 /* Info for the block device */ struct block2mtd_dev { @@ -217,7 +217,7 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) static struct block2mtd_dev *add_device(char *devname, int erase_size, - int timeout) + char *label, int timeout) { #ifndef MODULE int i; @@ -281,7 +281,10 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size, /* Setup the MTD structure */ /* make the name contain the block device in */ - name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname); + if (!label) + name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname); + else + name = kstrdup(label, GFP_KERNEL); if (!name) goto err_destroy_mutex; @@ -308,7 +311,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size, list_add(&dev->list, &blkmtd_device_list); pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n", dev->mtd.index, - dev->mtd.name + strlen("block2mtd: "), + label ? label : dev->mtd.name + strlen("block2mtd: "), dev->mtd.erasesize >> 10, dev->mtd.erasesize); return dev; @@ -386,6 +389,7 @@ static int block2mtd_setup2(const char *val) char *str = buf; char *token[BLOCK2MTD_PARAM_MAX_COUNT]; char *name; + char *label = NULL; size_t erase_size = PAGE_SIZE; unsigned long timeout = MTD_DEFAULT_TIMEOUT; int i, ret; @@ -417,7 +421,8 @@ static int block2mtd_setup2(const char *val) return 0; } - if (token[1]) { + /* Optional argument when custom label is used */ + if (token[1] && strlen(token[1])) { ret = parse_num(&erase_size, token[1]); if (ret) { pr_err("illegal erase size\n"); @@ -425,7 +430,12 @@ static int block2mtd_setup2(const char *val) } } - add_device(name, erase_size, timeout); + if (token[2]) { + label = token[2]; + pr_info("Using custom MTD label '%s' for dev %s\n", label, name); + } + + add_device(name, erase_size, label, timeout); return 0; } @@ -459,7 +469,7 @@ static int block2mtd_setup(const char *val, const struct kernel_param *kp) module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200); -MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=[,]\""); +MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=[,[][,