[PATCH] DM 6/6: Support arbitrary number of target params

From: Kevin Corry
Date: Mon Sep 22 2003 - 10:58:53 EST


Support an arbitrary number of target parameters. [Alasdair Kergon]

--- diff/drivers/md/dm-table.c 2003-09-17 12:28:06.000000000 +0100
+++ source/drivers/md/dm-table.c 2003-09-17 13:09:41.000000000 +0100
@@ -534,12 +534,36 @@
}

/*
+ * Used to dynamically allocate the arg array.
+ */
+static char **realloc_argv(unsigned *array_size, char **old_argv)
+{
+ char **argv;
+ unsigned new_size;
+
+ new_size = *array_size ? *array_size * 2 : 64;
+ argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
+ if (argv) {
+ memcpy(argv, old_argv, *array_size * sizeof(*argv));
+ *array_size = new_size;
+ }
+
+ kfree(old_argv);
+ return argv;
+}
+
+/*
* Destructively splits up the argument list to pass to ctr.
*/
-static int split_args(int max, int *argc, char **argv, char *input)
+static int split_args(int *argc, char ***argvp, char *input)
{
- char *start, *end = input, *out;
+ char *start, *end = input, *out, **argv = NULL;
+ unsigned array_size = 0;
+
*argc = 0;
+ argv = realloc_argv(&array_size, argv);
+ if (!argv)
+ return -ENOMEM;

while (1) {
start = end;
@@ -568,8 +592,11 @@
}

/* have we already filled the array ? */
- if ((*argc + 1) > max)
- return -EINVAL;
+ if ((*argc + 1) > array_size) {
+ argv = realloc_argv(&array_size, argv);
+ if (!argv)
+ return -ENOMEM;
+ }

/* we know this is whitespace */
if (*end)
@@ -581,6 +608,7 @@
(*argc)++;
}

+ *argvp = argv;
return 0;
}

@@ -588,7 +616,7 @@
sector_t start, sector_t len, char *params)
{
int r = -EINVAL, argc;
- char *argv[32];
+ char **argv;
struct dm_target *tgt;

if ((r = check_space(t)))
@@ -617,13 +645,14 @@
goto bad;
}

- r = split_args(ARRAY_SIZE(argv), &argc, argv, params);
+ r = split_args(&argc, &argv, params);
if (r) {
- tgt->error = "couldn't split parameters";
+ tgt->error = "couldn't split parameters (insufficient memory)";
goto bad;
}

r = tgt->type->ctr(tgt, argc, argv);
+ kfree(argv);
if (r)
goto bad;


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/