[PATCH] mtd: cmdlinepart: use cmdline partition parser lib
Ezequiel Garcia
ezequiel.garcia at free-electrons.com
Sun Oct 20 05:06:05 PDT 2013
Hi Cai,
Sorry for the late review. See below some minor comments.
On Thu, Aug 15, 2013 at 11:19:36AM +0000, Caizhiyong wrote:
> From: Cai Zhiyong <caizhiyong at huawei.com>
>
> MTD cmdline partition use cmdline partition parser lib
>
> reference: https://lkml.org/lkml/2013/8/6/550
>
How about some more verbose commit message explaining the impact
of this change, or clearly stating there's no functionality change
(as it should given the mtdparts parameter _must_ be kept compatible).
> Signed-off-by: Cai ZhiYong <caizhiyong at huawei.com>
> ---
> Documentation/block/cmdline-partition.txt | 93 +++++---
> block/cmdline-parser.c | 16 +-
> drivers/mtd/Kconfig | 1 +
> drivers/mtd/cmdlinepart.c | 361 ++++--------------------------
> include/linux/cmdline-parser.h | 8 +-
> 5 files changed, 111 insertions(+), 368 deletions(-)
>
This a nice diffstat, nice job!
> diff --git a/Documentation/block/cmdline-partition.txt b/Documentation/block/cmdline-partition.txt
> index 651863d..adc5f7a 100644
> --- a/Documentation/block/cmdline-partition.txt
> +++ b/Documentation/block/cmdline-partition.txt
> @@ -1,40 +1,59 @@
> Embedded device command line partition
> -=====================================================================
> -
> -Read block device partition table from command line.
> -The partition used for fixed block device (eMMC) embedded device.
> -It is no MBR, save storage space. Bootloader can be easily accessed
> -by absolute address of data on the block device.
> -Users can easily change the partition.
> -
> -The format for the command line is just like mtdparts:
> -
> -blkdevparts=<blkdev-def>[;<blkdev-def>]
> +Authors: Cai Zhiyong <caizhiyong at huawei.com>
> +
> +The format for the command line is as follows,
> +it is used by MTD device (reference drivers/mtd/cmdlinepart.c) and
> +block device (reference block/partitions/cmdline.c)
> +
> +================================================================================
> +For MTD device:
> + mtdparts=<mtddef>[;<mtddef]
> + <mtddef> := <mtd-id>:<partdef>[,<partdef>]
> + <partdef> := <size>[@<offset>][<name>][ro][lk]
> + <mtd-id> := unique name used in mapping driver/device (mtd->name)
> + <size> := standard linux memsize OR "-" to denote all remaining space
> + size is automatically truncated at end of device
> + if specified or trucated size is 0 the part is skipped
> + <offset> := standard linux memsize
> + if omitted the part will immediately follow the previous part
> + or 0 if the first part
> + <name> := '(' NAME ')'
> + NAME will appear in /proc/mtd
> +
> + <size> and <offset> can be specified such that the parts are out of order
> + in physical memory and may even overlap.
> +
> + The parts are assigned MTD numbers in the order they are specified in the
> + command line regardless of their order in physical memory.
> +
> + Examples:
> +
> + 1 NOR Flash, with 1 single writable partition:
> + edb7312-nor:-
> +
> + 1 NOR Flash with 2 partitions, 1 NAND with one
> + edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
> +
> +================================================================================
> +For block device:
> + blkdevparts=<blkdev-def>[;<blkdev-def>]
> <blkdev-def> := <blkdev-id>:<partdef>[,<partdef>]
> - <partdef> := <size>[@<offset>](part-name)
> -
> -<blkdev-id>
> - block device disk name, embedded device used fixed block device,
> - it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
> -
> -<size>
> - partition size, in bytes, such as: 512, 1m, 1G.
> -
> -<offset>
> - partition start address, in bytes.
> -
> -(part-name)
> - partition name, kernel send uevent with "PARTNAME". application can create
> - a link to block device partition with the name "PARTNAME".
> - user space application can access partition by partition name.
> -
> -Example:
> - eMMC disk name is "mmcblk0" and "mmcblk0boot0"
> -
> - bootargs:
> + <partdef> := <size>[@<offset>][<name>]
> + <blkdev-id>
> + block device disk name, embedded device used fixed block device,
> + it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
> + <size> := standard linux memsize OR "-" to denote all remaining space
> + size is automatically truncated at end of device
> + if specified or trucated size is 0 the part is skipped
> + <offset> := standard linux memsize
> + if omitted the part will immediately follow the previous part
> + or 0 if the first part
> + <name> := '(' NAME ')'
> + partition name, kernel send uevent with "PARTNAME". application could
> + create a link to block device partition with the name "PARTNAME".
> + user space application can access partition by partition name.
> +
> + Example:
> +
> + eMMC disk name is "mmcblk0" and "mmcblk0boot0", bootargs:
> 'blkdevparts=mmcblk0:1G(data0),1G(data1),-;mmcblk0boot0:1m(boot),-(kernel)'
> -
> - dmesg:
> - mmcblk0: p1(data0) p2(data1) p3()
> - mmcblk0boot0: p1(boot) p2(kernel)
> -
> diff --git a/block/cmdline-parser.c b/block/cmdline-parser.c
> index 18fb435..8c09db3 100644
> --- a/block/cmdline-parser.c
> +++ b/block/cmdline-parser.c
> @@ -4,8 +4,6 @@
> * Written by Cai Zhiyong <caizhiyong at huawei.com>
> *
> */
> -#include <linux/buffer_head.h>
> -#include <linux/module.h>
Hm.. this header removal seems an unrelated change, right?
I'd suggest to send a separate patch for this.
> #include <linux/cmdline-parser.h>
>
> static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
> @@ -158,6 +156,7 @@ void cmdline_parts_free(struct cmdline_parts **parts)
> *parts = next_parts;
> }
> }
> +EXPORT_SYMBOL(cmdline_parts_free);
>
> int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
> {
> @@ -205,6 +204,7 @@ fail:
> cmdline_parts_free(parts);
> goto done;
> }
> +EXPORT_SYMBOL(cmdline_parts_parse);
>
> struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
> const char *bdev)
> @@ -213,16 +213,17 @@ struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
> parts = parts->next_parts;
> return parts;
> }
> +EXPORT_SYMBOL(cmdline_parts_find);
>
> /*
> * add_part()
> * 0 success.
> * 1 can not add so many partitions.
> */
> -void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
> - int slot,
> - int (*add_part)(int, struct cmdline_subpart *, void *),
> - void *param)
> +int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
> + int slot,
> + int (*add_part)(int, struct cmdline_subpart *, void *),
> + void *param)
>
> {
> sector_t from = 0;
> @@ -246,4 +247,7 @@ void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
> if (add_part(slot, subpart, param))
> break;
> }
> +
> + return slot;
> }
> +EXPORT_SYMBOL(cmdline_parts_set);
> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
> index 5fab4e6e..6f7f9ca 100644
> --- a/drivers/mtd/Kconfig
> +++ b/drivers/mtd/Kconfig
> @@ -75,6 +75,7 @@ endif # MTD_REDBOOT_PARTS
>
> config MTD_CMDLINE_PARTS
> tristate "Command line partition table parsing"
> + select CMDLINE_PARSER
> depends on MTD
> ---help---
> Allow generic configuration of the MTD partition tables via the kernel
> diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
> index 721caeb..79bd584 100644
> --- a/drivers/mtd/cmdlinepart.c
> +++ b/drivers/mtd/cmdlinepart.c
> @@ -18,34 +18,8 @@
> * along with this program; if not, write to the Free Software
> * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> *
> - * The format for the command line is as follows:
> + * Verbose please reference "Documentation/block/cmdline-partition.txt"
> *
> - * mtdparts=<mtddef>[;<mtddef]
> - * <mtddef> := <mtd-id>:<partdef>[,<partdef>]
> - * <partdef> := <size>[@<offset>][<name>][ro][lk]
> - * <mtd-id> := unique name used in mapping driver/device (mtd->name)
> - * <size> := standard linux memsize OR "-" to denote all remaining space
> - * size is automatically truncated at end of device
> - * if specified or trucated size is 0 the part is skipped
> - * <offset> := standard linux memsize
> - * if omitted the part will immediately follow the previous part
> - * or 0 if the first part
> - * <name> := '(' NAME ')'
> - * NAME will appear in /proc/mtd
> - *
> - * <size> and <offset> can be specified such that the parts are out of order
> - * in physical memory and may even overlap.
> - *
> - * The parts are assigned MTD numbers in the order they are specified in the
> - * command line regardless of their order in physical memory.
> - *
> - * Examples:
> - *
> - * 1 NOR Flash, with 1 single writable partition:
> - * edb7312-nor:-
> - *
> - * 1 NOR Flash with 2 partitions, 1 NAND with one
> - * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
> */
>
> #include <linux/kernel.h>
> @@ -54,249 +28,43 @@
> #include <linux/mtd/partitions.h>
> #include <linux/module.h>
> #include <linux/err.h>
> +#include <linux/cmdline-parser.h>
>
> -/* error message prefix */
> -#define ERRP "mtd: "
> -
> -/* debug macro */
> -#if 0
> -#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
> -#else
> -#define dbg(x)
> -#endif
> -
> -
> -/* special size referring to all the remaining space in a partition */
> -#define SIZE_REMAINING ULLONG_MAX
> -#define OFFSET_CONTINUOUS ULLONG_MAX
> -
> -struct cmdline_mtd_partition {
> - struct cmdline_mtd_partition *next;
> - char *mtd_id;
> - int num_parts;
> - struct mtd_partition *parts;
> -};
> -
> -/* mtdpart_setup() parses into here */
> -static struct cmdline_mtd_partition *partitions;
> -
> -/* the command line passed to mtdpart_setup() */
> static char *mtdparts;
> -static char *cmdline;
> -static int cmdline_parsed;
> +static struct cmdline_parts *mtd_cmdline_parts;
>
> -/*
> - * Parse one partition definition for an MTD. Since there can be many
> - * comma separated partition definitions, this function calls itself
> - * recursively until no more partition definitions are found. Nice side
> - * effect: the memory to keep the mtd_partition structs and the names
> - * is allocated upon the last definition being found. At that point the
> - * syntax has been verified ok.
> - */
> -static struct mtd_partition * newpart(char *s,
> - char **retptr,
> - int *num_parts,
> - int this_part,
> - unsigned char **extra_mem_ptr,
> - int extra_mem_size)
> +static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
> {
> - struct mtd_partition *parts;
> - unsigned long long size, offset = OFFSET_CONTINUOUS;
> - char *name;
> - int name_len;
> - unsigned char *extra_mem;
> - char delim;
> - unsigned int mask_flags;
> -
> - /* fetch the partition size */
> - if (*s == '-') {
> - /* assign all remaining space to this partition */
> - size = SIZE_REMAINING;
> - s++;
> - } else {
> - size = memparse(s, &s);
> - if (size < PAGE_SIZE) {
> - printk(KERN_ERR ERRP "partition size too small (%llx)\n",
> - size);
> - return ERR_PTR(-EINVAL);
> - }
> - }
> + struct mtd_partition *mtdpart = &((struct mtd_partition *)param)[slot];
>
> - /* fetch partition name and flags */
> - mask_flags = 0; /* this is going to be a regular partition */
> - delim = 0;
> + mtdpart->offset = subpart->from;
> + mtdpart->size = subpart->size;
> + mtdpart->name = subpart->name;
> + mtdpart->mask_flags = 0;
>
> - /* check for offset */
> - if (*s == '@') {
> - s++;
> - offset = memparse(s, &s);
> - }
> -
> - /* now look for name */
> - if (*s == '(')
> - delim = ')';
> -
> - if (delim) {
> - char *p;
> -
> - name = ++s;
> - p = strchr(name, delim);
> - if (!p) {
> - printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
> - return ERR_PTR(-EINVAL);
> - }
> - name_len = p - name;
> - s = p + 1;
> - } else {
> - name = NULL;
> - name_len = 13; /* Partition_000 */
> - }
> -
> - /* record name length for memory allocation later */
> - extra_mem_size += name_len + 1;
> -
> - /* test for options */
> - if (strncmp(s, "ro", 2) == 0) {
> - mask_flags |= MTD_WRITEABLE;
> - s += 2;
> - }
> + if (subpart->flags & PF_RDONLY)
> + mtdpart->mask_flags |= MTD_WRITEABLE;
>
> /* if lk is found do NOT unlock the MTD partition*/
> - if (strncmp(s, "lk", 2) == 0) {
> - mask_flags |= MTD_POWERUP_LOCK;
> - s += 2;
> - }
> -
> - /* test if more partitions are following */
> - if (*s == ',') {
> - if (size == SIZE_REMAINING) {
> - printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
> - 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 (IS_ERR(parts))
> - return parts;
> - } else {
> - /* this is the last partition: allocate space for all */
> - int alloc_size;
> -
> - *num_parts = this_part + 1;
> - alloc_size = *num_parts * sizeof(struct mtd_partition) +
> - extra_mem_size;
> -
> - parts = kzalloc(alloc_size, GFP_KERNEL);
> - if (!parts)
> - 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) */
> - parts[this_part].size = size;
> - parts[this_part].offset = offset;
> - parts[this_part].mask_flags = mask_flags;
> - if (name)
> - strlcpy(extra_mem, name, name_len + 1);
> - else
> - sprintf(extra_mem, "Partition_%03d", this_part);
> - parts[this_part].name = extra_mem;
> - extra_mem += name_len + 1;
> -
> - dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n",
> - this_part, parts[this_part].name, parts[this_part].offset,
> - parts[this_part].size, parts[this_part].mask_flags));
> + if (subpart->flags & PF_POWERUP_LOCK)
> + mtdpart->mask_flags |= MTD_POWERUP_LOCK;
>
> - /* return (updated) pointer to extra_mem memory */
> - if (extra_mem_ptr)
> - *extra_mem_ptr = extra_mem;
> -
> - /* return (updated) pointer command line string */
> - *retptr = s;
> -
> - /* return partition table */
> - return parts;
> + return 0;
> }
>
> /*
> - * Parse the command line.
> + * This is the handler for our kernel parameter, called from
> + * main.c::checksetup(). Note that we can not yet kmalloc() anything,
> + * so we only save the commandline for later processing.
> + *
> + * This function needs to be visible for bootloaders.
> */
> -static int mtdpart_setup_real(char *s)
> +static int __init mtdpart_setup(char *s)
> {
> - cmdline_parsed = 1;
> -
> - for( ; s != NULL; )
> - {
> - struct cmdline_mtd_partition *this_mtd;
> - struct mtd_partition *parts;
> - int mtd_id_len, num_parts;
> - char *p, *mtd_id;
> -
> - mtd_id = s;
> -
> - /* fetch <mtd-id> */
> - p = strchr(s, ':');
> - if (!p) {
> - printk(KERN_ERR ERRP "no mtd-id\n");
> - return -EINVAL;
> - }
> - mtd_id_len = p - mtd_id;
> -
> - dbg(("parsing <%s>\n", p+1));
> -
> - /*
> - * parse one mtd. have it reserve memory for the
> - * struct cmdline_mtd_partition and the mtd-id string.
> - */
> - parts = newpart(p + 1, /* cmdline */
> - &s, /* out: updated cmdline ptr */
> - &num_parts, /* out: number of parts */
> - 0, /* first partition */
> - (unsigned char**)&this_mtd, /* out: extra mem */
> - mtd_id_len + 1 + sizeof(*this_mtd) +
> - sizeof(void*)-1 /*alignment*/);
> - if (IS_ERR(parts)) {
> - /*
> - * An error occurred. We're either:
> - * a) out of memory, or
> - * b) in the middle of the partition spec
> - * Either way, this mtd is hosed and we're
> - * unlikely to succeed in parsing any more
> - */
> - return PTR_ERR(parts);
> - }
> -
> - /* align this_mtd */
> - this_mtd = (struct cmdline_mtd_partition *)
> - ALIGN((unsigned long)this_mtd, sizeof(void *));
> - /* enter results */
> - this_mtd->parts = parts;
> - this_mtd->num_parts = num_parts;
> - this_mtd->mtd_id = (char*)(this_mtd + 1);
> - strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
> -
> - /* link into chain */
> - this_mtd->next = partitions;
> - partitions = this_mtd;
> -
> - dbg(("mtdid=<%s> num_parts=<%d>\n",
> - this_mtd->mtd_id, this_mtd->num_parts));
> -
> -
> - /* EOS - we're done */
> - if (*s == 0)
> - break;
> -
> - /* does another spec follow? */
> - if (*s != ';') {
> - printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
> - return -EINVAL;
> - }
> - s++;
> - }
> -
> - return 0;
> + mtdparts = s;
> + return 1;
> }
> +__setup("mtdparts=", mtdpart_setup);
>
> /*
> * Main function to be called from the MTD mapping driver/device to
> @@ -309,82 +77,35 @@ static int parse_cmdline_partitions(struct mtd_info *master,
> struct mtd_partition **pparts,
> struct mtd_part_parser_data *data)
> {
> - unsigned long long offset;
> - int i, err;
> - struct cmdline_mtd_partition *part;
> - const char *mtd_id = master->name;
> + struct cmdline_parts *parts;
>
> - /* parse command line */
> - if (!cmdline_parsed) {
> - err = mtdpart_setup_real(cmdline);
> - if (err)
> - return err;
> - }
> + if (mtdparts) {
> + if (mtd_cmdline_parts)
> + cmdline_parts_free(&mtd_cmdline_parts);
> +
> + if (cmdline_parts_parse(&mtd_cmdline_parts, mtdparts)) {
> + mtdparts = NULL;
> + return -EINVAL;
> + }
>
> - /*
> - * Search for the partition definition matching master->name.
> - * If master->name is not set, stop at first partition definition.
> - */
> - for (part = partitions; part; part = part->next) {
> - if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
> - break;
> + mtdparts = NULL;
> }
>
> - if (!part)
> + if (!mtd_cmdline_parts)
> return 0;
>
> - for (i = 0, offset = 0; i < part->num_parts; i++) {
> - if (part->parts[i].offset == OFFSET_CONTINUOUS)
> - part->parts[i].offset = offset;
> - else
> - offset = part->parts[i].offset;
> -
> - if (part->parts[i].size == SIZE_REMAINING)
> - part->parts[i].size = master->size - offset;
> -
> - if (offset + part->parts[i].size > master->size) {
> - printk(KERN_WARNING ERRP
> - "%s: partitioning exceeds flash size, truncating\n",
> - part->mtd_id);
> - part->parts[i].size = master->size - offset;
> - }
> - offset += part->parts[i].size;
> -
> - if (part->parts[i].size == 0) {
> - printk(KERN_WARNING ERRP
> - "%s: skipping zero sized partition\n",
> - part->mtd_id);
> - part->num_parts--;
> - memmove(&part->parts[i], &part->parts[i + 1],
> - sizeof(*part->parts) * (part->num_parts - i));
> - i--;
> - }
> - }
> + parts = cmdline_parts_find(mtd_cmdline_parts, master->name);
> + if (!parts)
> + return 0;
>
> - *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,
> - GFP_KERNEL);
> + *pparts = kzalloc(sizeof(**pparts) * parts->nr_subparts, GFP_KERNEL);
> if (!*pparts)
> return -ENOMEM;
>
> - return part->num_parts;
> -}
> -
> -
> -/*
> - * This is the handler for our kernel parameter, called from
> - * main.c::checksetup(). Note that we can not yet kmalloc() anything,
> - * so we only save the commandline for later processing.
> - *
> - * This function needs to be visible for bootloaders.
> - */
> -static int __init mtdpart_setup(char *s)
> -{
> - cmdline = s;
> - return 1;
> + return cmdline_parts_set(parts, master->size, 0, add_part,
> + (void *)*pparts);
> }
>
> -__setup("mtdparts=", mtdpart_setup);
> -
> static struct mtd_part_parser cmdline_parser = {
> .owner = THIS_MODULE,
> .parse_fn = parse_cmdline_partitions,
> @@ -393,8 +114,6 @@ static struct mtd_part_parser cmdline_parser = {
>
> static int __init cmdline_parser_init(void)
> {
> - if (mtdparts)
> - mtdpart_setup(mtdparts);
> return register_mtd_parser(&cmdline_parser);
> }
>
> diff --git a/include/linux/cmdline-parser.h b/include/linux/cmdline-parser.h
> index 98e892e..43b65a9 100644
> --- a/include/linux/cmdline-parser.h
> +++ b/include/linux/cmdline-parser.h
> @@ -35,9 +35,9 @@ int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline);
> struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
> const char *bdev);
>
> -void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
> - int slot,
> - int (*add_part)(int, struct cmdline_subpart *, void *),
> - void *param);
> +int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
> + int slot,
> + int (*add_part)(int, struct cmdline_subpart *, void *),
> + void *param);
>
> #endif /* CMDLINEPARSEH */
> --
> 1.8.1.5
>
I'd like to review the patch in detail and test it, but being a bit old,
the patch doesn't apply as it is on v3.12-rc5. Care to resend an update?
Brian: I saw you want to move forward with this. I guess we can give
it a test, and if all the possible 'mtdparts' use cases work, then
we shouldn't object the cleanup, right?
--
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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