| Message ID | 20211008140835.476949-1-troglobit@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v2,1/1] mtd: block2mtd: add support for an optional custom MTD label | expand |
Hi Joachim, troglobit@gmail.com wrote on Fri, 8 Oct 2021 16:08:35 +0200: > 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 > > Notioce 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 <troglobit@gmail.com> > Reviewed-by: Miquèl Raynal <miquel.raynal@bootlin.com> > --- > v2: > * Variables and arguments on their own lines > * Add comment to explain why we need strlen() > * Refactor hard coded constants with a define > * Spell and grammar check commit message > --- > drivers/mtd/devices/block2mtd.c | 29 +++++++++++++++++++++-------- > 1 file changed, 21 insertions(+), 8 deletions(-) > > diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c > index c08721b11642..40d7211485da 100644 > --- a/drivers/mtd/devices/block2mtd.c > +++ b/drivers/mtd/devices/block2mtd.c > @@ -31,6 +31,9 @@ > #include <linux/slab.h> > #include <linux/major.h> > > +/* Maximum number of comma-separated items in the 'block2mtd=' parameter */ > +#define BLOCK2MTD_PARAM_MAX_COUNT 3 > + > /* Info for the block device */ > struct block2mtd_dev { > struct list_head list; > @@ -214,7 +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; > @@ -278,7 +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; > > @@ -305,7 +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; > > @@ -381,8 +387,9 @@ static int block2mtd_setup2(const char *val) > /* 80 for device, 12 for erase size, 80 for name, 8 for timeout */ > char buf[80 + 12 + 80 + 8]; > char *str = buf; > - char *token[2]; > + char *token[BLOCK2MTD_PARAM_MAX_COUNT]; I believe this change should still be kept in a separate patch. Otherwise looks fine. > char *name; > + char *label = NULL; > size_t erase_size = PAGE_SIZE; > unsigned long timeout = MTD_DEFAULT_TIMEOUT; > int i, ret; > @@ -395,7 +402,7 @@ static int block2mtd_setup2(const char *val) > strcpy(str, val); > kill_final_newline(str); > > - for (i = 0; i < 2; i++) > + for (i = 0; i < BLOCK2MTD_PARAM_MAX_COUNT; i++) > token[i] = strsep(&str, ","); > > if (str) { > @@ -414,7 +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"); > @@ -422,7 +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; > } > @@ -456,7 +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=<dev>[,<erasesize>]\""); > +MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,[<erasesize>][,<label>]]\""); > > static int __init block2mtd_init(void) > { Thanks, Miquèl
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index c08721b11642..40d7211485da 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -31,6 +31,9 @@ #include <linux/slab.h> #include <linux/major.h> +/* Maximum number of comma-separated items in the 'block2mtd=' parameter */ +#define BLOCK2MTD_PARAM_MAX_COUNT 3 + /* Info for the block device */ struct block2mtd_dev { struct list_head list; @@ -214,7 +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; @@ -278,7 +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; @@ -305,7 +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; @@ -381,8 +387,9 @@ static int block2mtd_setup2(const char *val) /* 80 for device, 12 for erase size, 80 for name, 8 for timeout */ char buf[80 + 12 + 80 + 8]; char *str = buf; - char *token[2]; + 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; @@ -395,7 +402,7 @@ static int block2mtd_setup2(const char *val) strcpy(str, val); kill_final_newline(str); - for (i = 0; i < 2; i++) + for (i = 0; i < BLOCK2MTD_PARAM_MAX_COUNT; i++) token[i] = strsep(&str, ","); if (str) { @@ -414,7 +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"); @@ -422,7 +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; } @@ -456,7 +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=<dev>[,<erasesize>]\""); +MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,[<erasesize>][,<label>]]\""); static int __init block2mtd_init(void) {
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 Notioce 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 <troglobit@gmail.com> Reviewed-by: Miquèl Raynal <miquel.raynal@bootlin.com> --- v2: * Variables and arguments on their own lines * Add comment to explain why we need strlen() * Refactor hard coded constants with a define * Spell and grammar check commit message --- drivers/mtd/devices/block2mtd.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)