[PATCH] block: add command line partition parser
From: Caizhiyong
Date: Tue Aug 13 2013 - 02:02:39 EST
From: Cai Zhiyong <caizhiyong@xxxxxxxxxx>
move the command line parser to a separate module, and change it into
library-style code.
reference: https://lkml.org/lkml/2013/8/6/550
Signed-off-by: Cai Zhiyong <caizhiyong@xxxxxxxxxx>
---
block/Kconfig | 6 +
block/Makefile | 1 +
block/cmdline-parser.c | 249 +++++++++++++++++++++++++++++++++
block/partitions/Kconfig | 1 +
block/partitions/cmdline.c | 311 ++++++-----------------------------------
include/linux/cmdline-parser.h | 43 ++++++
6 files changed, 342 insertions(+), 269 deletions(-)
create mode 100644 block/cmdline-parser.c
create mode 100644 include/linux/cmdline-parser.h
diff --git a/block/Kconfig b/block/Kconfig
index a7e40a7..7f38e40 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -99,6 +99,12 @@ config BLK_DEV_THROTTLING
See Documentation/cgroups/blkio-controller.txt for more information.
+config CMDLINE_PARSER
+ bool "Block device command line partition parser"
+ default n
+ ---help---
+ Parsing command line, get the partitions information.
+
menu "Partition Types"
source "block/partitions/Kconfig"
diff --git a/block/Makefile b/block/Makefile
index 39b76ba..4fa4be5 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o
+obj-$(CONFIG_CMDLINE_PARSER) += cmdline-parser.o
diff --git a/block/cmdline-parser.c b/block/cmdline-parser.c
new file mode 100644
index 0000000..18fb435
--- /dev/null
+++ b/block/cmdline-parser.c
@@ -0,0 +1,249 @@
+/*
+ * Parse command line, get partition information
+ *
+ * Written by Cai Zhiyong <caizhiyong@xxxxxxxxxx>
+ *
+ */
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/cmdline-parser.h>
+
+static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
+{
+ int ret = 0;
+ struct cmdline_subpart *new_subpart;
+
+ *subpart = NULL;
+
+ new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
+ if (!new_subpart)
+ return -ENOMEM;
+
+ if (*partdef == '-') {
+ new_subpart->size = (sector_t)(~0ULL);
+ partdef++;
+ } else {
+ new_subpart->size = (sector_t)memparse(partdef, &partdef);
+ if (new_subpart->size < (sector_t)PAGE_SIZE) {
+ pr_warn("cmdline partition size is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ if (*partdef == '@') {
+ partdef++;
+ new_subpart->from = (sector_t)memparse(partdef, &partdef);
+ } else {
+ new_subpart->from = (sector_t)(~0ULL);
+ }
+
+ if (*partdef == '(') {
+ int length;
+ char *next = strchr(++partdef, ')');
+
+ if (!next) {
+ pr_warn("cmdline partition format is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ length = min_t(int, next - partdef,
+ sizeof(new_subpart->name) - 1);
+ strncpy(new_subpart->name, partdef, length);
+ new_subpart->name[length] = '\0';
+
+ partdef = ++next;
+ } else
+ new_subpart->name[0] = '\0';
+
+ new_subpart->flags = 0;
+
+ if (!strncmp(partdef, "ro", 2)) {
+ new_subpart->flags |= PF_RDONLY;
+ partdef += 2;
+ }
+
+ if (!strncmp(partdef, "lk", 2)) {
+ new_subpart->flags |= PF_POWERUP_LOCK;
+ partdef += 2;
+ }
+
+ *subpart = new_subpart;
+ return 0;
+fail:
+ kfree(new_subpart);
+ return ret;
+}
+
+static void free_subpart(struct cmdline_parts *parts)
+{
+ struct cmdline_subpart *subpart;
+
+ while (parts->subpart) {
+ subpart = parts->subpart;
+ parts->subpart = subpart->next_subpart;
+ kfree(subpart);
+ }
+}
+
+static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
+{
+ int ret = -EINVAL;
+ char *next;
+ int length;
+ struct cmdline_subpart **next_subpart;
+ struct cmdline_parts *newparts;
+ char buf[BDEVNAME_SIZE + 32 + 4];
+
+ *parts = NULL;
+
+ newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
+ if (!newparts)
+ return -ENOMEM;
+
+ next = strchr(bdevdef, ':');
+ if (!next) {
+ pr_warn("cmdline partition has no block device.");
+ goto fail;
+ }
+
+ length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
+ strncpy(newparts->name, bdevdef, length);
+ newparts->name[length] = '\0';
+ newparts->nr_subparts = 0;
+
+ next_subpart = &newparts->subpart;
+
+ while (next && *(++next)) {
+ bdevdef = next;
+ next = strchr(bdevdef, ',');
+
+ length = (!next) ? (sizeof(buf) - 1) :
+ min_t(int, next - bdevdef, sizeof(buf) - 1);
+
+ strncpy(buf, bdevdef, length);
+ buf[length] = '\0';
+
+ ret = parse_subpart(next_subpart, buf);
+ if (ret)
+ goto fail;
+
+ newparts->nr_subparts++;
+ next_subpart = &(*next_subpart)->next_subpart;
+ }
+
+ if (!newparts->subpart) {
+ pr_warn("cmdline partition has no valid partition.");
+ goto fail;
+ }
+
+ *parts = newparts;
+
+ return 0;
+fail:
+ free_subpart(newparts);
+ kfree(newparts);
+ return ret;
+}
+
+void cmdline_parts_free(struct cmdline_parts **parts)
+{
+ struct cmdline_parts *next_parts;
+
+ while (*parts) {
+ next_parts = (*parts)->next_parts;
+ free_subpart(*parts);
+ kfree(*parts);
+ *parts = next_parts;
+ }
+}
+
+int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
+{
+ int ret;
+ char *buf;
+ char *pbuf;
+ char *next;
+ struct cmdline_parts **next_parts;
+
+ *parts = NULL;
+
+ next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ next_parts = parts;
+
+ while (next && *pbuf) {
+ next = strchr(pbuf, ';');
+ if (next)
+ *next = '\0';
+
+ ret = parse_parts(next_parts, pbuf);
+ if (ret)
+ goto fail;
+
+ if (next)
+ pbuf = ++next;
+
+ next_parts = &(*next_parts)->next_parts;
+ }
+
+ if (!*parts) {
+ pr_warn("cmdline partition has no valid partition.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = 0;
+done:
+ kfree(buf);
+ return ret;
+
+fail:
+ cmdline_parts_free(parts);
+ goto done;
+}
+
+struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
+ const char *bdev)
+{
+ while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
+ parts = parts->next_parts;
+ return parts;
+}
+
+/*
+ * 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)
+
+{
+ sector_t from = 0;
+ struct cmdline_subpart *subpart;
+
+ for (subpart = parts->subpart; subpart;
+ subpart = subpart->next_subpart, slot++) {
+ if (subpart->from == (sector_t)(~0ULL))
+ subpart->from = from;
+ else
+ from = subpart->from;
+
+ if (from >= disk_size)
+ break;
+
+ if (subpart->size > (disk_size - from))
+ subpart->size = disk_size - from;
+
+ from += subpart->size;
+
+ if (add_part(slot, subpart, param))
+ break;
+ }
+}
diff --git a/block/partitions/Kconfig b/block/partitions/Kconfig
index 2ebf251..87a3208 100644
--- a/block/partitions/Kconfig
+++ b/block/partitions/Kconfig
@@ -263,6 +263,7 @@ config SYSV68_PARTITION
config CMDLINE_PARTITION
bool "Command line partition support" if PARTITION_ADVANCED
+ select CMDLINE_PARSER
help
Say Y here if you would read the partitions table from bootargs.
The format for the command line is just like mtdparts.
diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c
index 1a1eac7..56cf4ff 100644
--- a/block/partitions/cmdline.c
+++ b/block/partitions/cmdline.c
@@ -8,219 +8,54 @@
* by absolute address of data on the block device.
* Users can easily change the partition.
*
- * This code reference MTD partition, source "drivers/mtd/cmdlinepart.c"
* The format for the command line is just like mtdparts.
*
* Verbose config please reference "Documentation/block/cmdline-partition.txt"
*
*/
-#include <linux/buffer_head.h>
-#include <linux/module.h>
-#include <linux/ctype.h>
+#include <linux/cmdline-parser.h>
#include "check.h"
#include "cmdline.h"
-struct cmdline_subpart {
- char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
- sector_t from;
- sector_t size;
- struct cmdline_subpart *next_subpart;
-};
+static char *cmdline;
+static struct cmdline_parts *bdev_parts;
-struct cmdline_parts {
- char name[BDEVNAME_SIZE]; /* block device, such as 'mmcblk0' */
- struct cmdline_subpart *subpart;
- struct cmdline_parts *next_parts;
-};
-
-static char *cmdline_string;
-static struct cmdline_parts *cmdline_parts;
-
-static int parse_subpart(struct cmdline_subpart **subpart, char *cmdline)
-{
- int ret = 0;
- struct cmdline_subpart *new_subpart;
-
- *subpart = NULL;
-
- new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
- if (!new_subpart)
- return -ENOMEM;
-
- if (*cmdline == '-') {
- new_subpart->size = (sector_t)(~0ULL);
- cmdline++;
- } else {
- new_subpart->size = (sector_t)memparse(cmdline, &cmdline);
- if (new_subpart->size < (sector_t)PAGE_SIZE) {
- pr_warn("cmdline partition size is invalid.");
- ret = -EINVAL;
- goto fail;
- }
- }
-
- if (*cmdline == '@') {
- cmdline++;
- new_subpart->from = (sector_t)memparse(cmdline, &cmdline);
- } else {
- new_subpart->from = (sector_t)(~0ULL);
- }
-
- if (*cmdline == '(') {
- int length;
- char *next = strchr(++cmdline, ')');
-
- if (!next) {
- pr_warn("cmdline partition format is invalid.");
- ret = -EINVAL;
- goto fail;
- }
-
- length = min_t(int, next - cmdline,
- sizeof(new_subpart->name) - 1);
- strncpy(new_subpart->name, cmdline, length);
- new_subpart->name[length] = '\0';
-
- cmdline = ++next;
- } else
- new_subpart->name[0] = '\0';
-
- *subpart = new_subpart;
- return 0;
-fail:
- kfree(new_subpart);
- return ret;
-}
-
-static void free_subpart(struct cmdline_parts *parts)
-{
- struct cmdline_subpart *subpart;
-
- while (parts->subpart) {
- subpart = parts->subpart;
- parts->subpart = subpart->next_subpart;
- kfree(subpart);
- }
-}
-
-static void free_parts(struct cmdline_parts **parts)
-{
- struct cmdline_parts *next_parts;
-
- while (*parts) {
- next_parts = (*parts)->next_parts;
- free_subpart(*parts);
- kfree(*parts);
- *parts = next_parts;
- }
-}
-
-static int parse_parts(struct cmdline_parts **parts, const char *cmdline)
+static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
{
- int ret = -EINVAL;
- char *next;
- int length;
- struct cmdline_subpart **next_subpart;
- struct cmdline_parts *newparts;
- char buf[BDEVNAME_SIZE + 32 + 4];
+ int label_min;
+ struct partition_meta_info *info;
+ char tmp[sizeof(info->volname) + 4];
+ struct parsed_partitions *state = (struct parsed_partitions *)param;
- *parts = NULL;
+ if (slot >= state->limit)
+ return 1;
- newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
- if (!newparts)
- return -ENOMEM;
+ put_partition(state, slot, subpart->from >> 9,
+ subpart->size >> 9);
- next = strchr(cmdline, ':');
- if (!next) {
- pr_warn("cmdline partition has no block device.");
- goto fail;
- }
-
- length = min_t(int, next - cmdline, sizeof(newparts->name) - 1);
- strncpy(newparts->name, cmdline, length);
- newparts->name[length] = '\0';
-
- next_subpart = &newparts->subpart;
+ info = &state->parts[slot].info;
- while (next && *(++next)) {
- cmdline = next;
- next = strchr(cmdline, ',');
+ label_min = min_t(int, sizeof(info->volname) - 1,
+ sizeof(subpart->name));
+ strncpy(info->volname, subpart->name, label_min);
+ info->volname[label_min] = '\0';
- length = (!next) ? (sizeof(buf) - 1) :
- min_t(int, next - cmdline, sizeof(buf) - 1);
+ snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
- strncpy(buf, cmdline, length);
- buf[length] = '\0';
-
- ret = parse_subpart(next_subpart, buf);
- if (ret)
- goto fail;
-
- next_subpart = &(*next_subpart)->next_subpart;
- }
-
- if (!newparts->subpart) {
- pr_warn("cmdline partition has no valid partition.");
- goto fail;
- }
-
- *parts = newparts;
+ state->parts[slot].has_info = true;
return 0;
-fail:
- free_subpart(newparts);
- kfree(newparts);
- return ret;
}
-static int parse_cmdline(struct cmdline_parts **parts, const char *cmdline)
+static int __init cmdline_parts_setup(char *s)
{
- int ret;
- char *buf;
- char *pbuf;
- char *next;
- struct cmdline_parts **next_parts;
-
- *parts = NULL;
-
- next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- next_parts = parts;
-
- while (next && *pbuf) {
- next = strchr(pbuf, ';');
- if (next)
- *next = '\0';
-
- ret = parse_parts(next_parts, pbuf);
- if (ret)
- goto fail;
-
- if (next)
- pbuf = ++next;
-
- next_parts = &(*next_parts)->next_parts;
- }
-
- if (!*parts) {
- pr_warn("cmdline partition has no valid partition.");
- ret = -EINVAL;
- goto fail;
- }
-
- ret = 0;
-done:
- kfree(buf);
- return ret;
-
-fail:
- free_parts(parts);
- goto done;
+ cmdline = s;
+ return 1;
}
+__setup("blkdevparts=", cmdline_parts_setup);
/*
* Purpose: allocate cmdline partitions.
@@ -229,98 +64,36 @@ fail:
* 0 if this isn't our partition table
* 1 if successful
*/
-static int parse_partitions(struct parsed_partitions *state,
- struct cmdline_parts *parts)
+int cmdline_partition(struct parsed_partitions *state)
{
- int slot;
- sector_t from = 0;
sector_t disk_size;
- char buf[BDEVNAME_SIZE];
- struct cmdline_subpart *subpart;
+ char bdev[BDEVNAME_SIZE];
+ struct cmdline_parts *parts;
+
+ if (cmdline) {
+ if (bdev_parts)
+ cmdline_parts_free(&bdev_parts);
- bdevname(state->bdev, buf);
+ if (cmdline_parts_parse(&bdev_parts, cmdline)) {
+ cmdline = NULL;
+ return -1;
+ }
+ cmdline = NULL;
+ }
- while (parts && strncmp(buf, parts->name, BDEVNAME_SIZE))
- parts = parts->next_parts;
+ if (!bdev_parts)
+ return 0;
+ bdevname(state->bdev, bdev);
+ parts = cmdline_parts_find(bdev_parts, bdev);
if (!parts)
return 0;
disk_size = get_capacity(state->bdev->bd_disk) << 9;
- for (slot = 1, subpart = parts->subpart;
- subpart && slot < state->limit;
- subpart = subpart->next_subpart, slot++) {
- int label_min;
- struct partition_meta_info *info;
- char tmp[sizeof(info->volname) + 4];
-
- if (subpart->from == (sector_t)(~0ULL))
- subpart->from = from;
- else
- from = subpart->from;
-
- if (from >= disk_size)
- break;
-
- if (subpart->size > (disk_size - from))
- subpart->size = disk_size - from;
-
- from += subpart->size;
-
- put_partition(state, slot, subpart->from >> 9,
- subpart->size >> 9);
-
- info = &state->parts[slot].info;
-
- label_min = min_t(int, sizeof(info->volname) - 1,
- sizeof(subpart->name));
- strncpy(info->volname, subpart->name, label_min);
- info->volname[label_min] = '\0';
-
- snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
- strlcat(state->pp_buf, tmp, PAGE_SIZE);
-
- state->parts[slot].has_info = true;
- }
+ cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
strlcat(state->pp_buf, "\n", PAGE_SIZE);
return 1;
}
-
-static int __init cmdline_parts_setup(char *s)
-{
- cmdline_string = s;
- return 1;
-}
-__setup("blkdevparts=", cmdline_parts_setup);
-
-/*
- * Purpose: allocate cmdline partitions.
- * Returns:
- * -1 if unable to read the partition table
- * 0 if this isn't our partition table
- * 1 if successful
- */
-int cmdline_partition(struct parsed_partitions *state)
-{
- if (cmdline_string) {
- if (cmdline_parts)
- free_parts(&cmdline_parts);
-
- if (parse_cmdline(&cmdline_parts, cmdline_string))
- goto fail;
-
- cmdline_string = NULL;
- }
-
- if (!cmdline_parts)
- return 0;
-
- return parse_partitions(state, cmdline_parts);
-
-fail:
- cmdline_string = NULL;
- return -1;
-}
diff --git a/include/linux/cmdline-parser.h b/include/linux/cmdline-parser.h
new file mode 100644
index 0000000..98e892e
--- /dev/null
+++ b/include/linux/cmdline-parser.h
@@ -0,0 +1,43 @@
+/*
+ * Parsing command line, get the partitions information.
+ *
+ * Written by Cai Zhiyong <caizhiyong@xxxxxxxxxx>
+ *
+ */
+#ifndef CMDLINEPARSEH
+#define CMDLINEPARSEH
+
+#include <linux/blkdev.h>
+
+/* partition flags */
+#define PF_RDONLY 0x01 /* Device is read only */
+#define PF_POWERUP_LOCK 0x02 /* Always locked after reset */
+
+struct cmdline_subpart {
+ char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
+ sector_t from;
+ sector_t size;
+ int flags;
+ struct cmdline_subpart *next_subpart;
+};
+
+struct cmdline_parts {
+ char name[BDEVNAME_SIZE]; /* block device, such as 'mmcblk0' */
+ unsigned int nr_subparts;
+ struct cmdline_subpart *subpart;
+ struct cmdline_parts *next_parts;
+};
+
+void cmdline_parts_free(struct cmdline_parts **parts);
+
+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);
+
+#endif /* CMDLINEPARSEH */
--
1.8.1.5
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