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path: root/arch/um/drivers/ubd_kern.c
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Diffstat (limited to 'arch/um/drivers/ubd_kern.c')
-rw-r--r--arch/um/drivers/ubd_kern.c132
1 files changed, 74 insertions, 58 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 49c047b75cc5..f4db97efc014 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -286,7 +286,7 @@ static int parse_unit(char **ptr)
* otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
* should not be freed on exit.
*/
-static int ubd_setup_common(char *str, int *index_out)
+static int ubd_setup_common(char *str, int *index_out, char **error_out)
{
struct ubd *ubd_dev;
struct openflags flags = global_openflags;
@@ -302,56 +302,54 @@ static int ubd_setup_common(char *str, int *index_out)
str++;
if(!strcmp(str, "sync")){
global_openflags = of_sync(global_openflags);
- return(0);
+ return 0;
}
major = simple_strtoul(str, &end, 0);
if((*end != '\0') || (end == str)){
- printk(KERN_ERR
- "ubd_setup : didn't parse major number\n");
- return(1);
+ *error_out = "Didn't parse major number";
+ return -EINVAL;
}
- err = 1;
- mutex_lock(&ubd_lock);
- if(fake_major != MAJOR_NR){
- printk(KERN_ERR "Can't assign a fake major twice\n");
- goto out1;
- }
+ err = -EINVAL;
+ mutex_lock(&ubd_lock);
+ if(fake_major != MAJOR_NR){
+ *error_out = "Can't assign a fake major twice";
+ goto out1;
+ }
- fake_major = major;
+ fake_major = major;
printk(KERN_INFO "Setting extra ubd major number to %d\n",
major);
- err = 0;
- out1:
- mutex_unlock(&ubd_lock);
- return(err);
+ err = 0;
+ out1:
+ mutex_unlock(&ubd_lock);
+ return err;
}
n = parse_unit(&str);
if(n < 0){
- printk(KERN_ERR "ubd_setup : couldn't parse unit number "
- "'%s'\n", str);
- return(1);
+ *error_out = "Couldn't parse device number";
+ return -EINVAL;
}
if(n >= MAX_DEV){
- printk(KERN_ERR "ubd_setup : index %d out of range "
- "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1);
- return(1);
+ *error_out = "Device number out of range";
+ return 1;
}
- err = 1;
+ err = -EBUSY;
mutex_lock(&ubd_lock);
ubd_dev = &ubd_devs[n];
if(ubd_dev->file != NULL){
- printk(KERN_ERR "ubd_setup : device already configured\n");
+ *error_out = "Device is already configured";
goto out;
}
if (index_out)
*index_out = n;
+ err = -EINVAL;
for (i = 0; i < sizeof("rscd="); i++) {
switch (*str) {
case 'r':
@@ -370,47 +368,54 @@ static int ubd_setup_common(char *str, int *index_out)
str++;
goto break_loop;
default:
- printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r, s, c, or d)\n");
+ *error_out = "Expected '=' or flag letter "
+ "(r, s, c, or d)";
goto out;
}
str++;
}
- if (*str == '=')
- printk(KERN_ERR "ubd_setup : Too many flags specified\n");
- else
- printk(KERN_ERR "ubd_setup : Expected '='\n");
+ if (*str == '=')
+ *error_out = "Too many flags specified";
+ else
+ *error_out = "Missing '='";
goto out;
break_loop:
- err = 0;
backing_file = strchr(str, ',');
- if (!backing_file) {
+ if (backing_file == NULL)
backing_file = strchr(str, ':');
- }
- if(backing_file){
- if(ubd_dev->no_cow)
- printk(KERN_ERR "Can't specify both 'd' and a "
- "cow file\n");
+ if(backing_file != NULL){
+ if(ubd_dev->no_cow){
+ *error_out = "Can't specify both 'd' and a cow file";
+ goto out;
+ }
else {
*backing_file = '\0';
backing_file++;
}
}
+ err = 0;
ubd_dev->file = str;
ubd_dev->cow.file = backing_file;
ubd_dev->boot_openflags = flags;
out:
mutex_unlock(&ubd_lock);
- return(err);
+ return err;
}
static int ubd_setup(char *str)
{
- ubd_setup_common(str, NULL);
- return(1);
+ char *error;
+ int err;
+
+ err = ubd_setup_common(str, NULL, &error);
+ if(err)
+ printk(KERN_ERR "Failed to initialize device with \"%s\" : "
+ "%s\n", str, error);
+ return 1;
}
__setup("ubd", ubd_setup);
@@ -422,7 +427,7 @@ __uml_help(ubd_setup,
" use either a ':' or a ',': the first one allows writing things like;\n"
" ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
" while with a ',' the shell would not expand the 2nd '~'.\n"
-" When using only one filename, UML will detect whether to thread it like\n"
+" When using only one filename, UML will detect whether to treat it like\n"
" a COW file or a backing file. To override this detection, add the 'd'\n"
" flag:\n"
" ubd0d=BackingFile\n"
@@ -668,18 +673,19 @@ static int ubd_disk_register(int major, u64 size, int unit,
#define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
-static int ubd_add(int n)
+static int ubd_add(int n, char **error_out)
{
struct ubd *ubd_dev = &ubd_devs[n];
- int err;
+ int err = 0;
- err = -ENODEV;
if(ubd_dev->file == NULL)
goto out;
err = ubd_file_size(ubd_dev, &ubd_dev->size);
- if(err < 0)
+ if(err < 0){
+ *error_out = "Couldn't determine size of device's file";
goto out;
+ }
ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
@@ -701,28 +707,31 @@ out:
return err;
}
-static int ubd_config(char *str)
+static int ubd_config(char *str, char **error_out)
{
int n, ret;
+ /* This string is possibly broken up and stored, so it's only
+ * freed if ubd_setup_common fails, or if only general options
+ * were set.
+ */
str = kstrdup(str, GFP_KERNEL);
if (str == NULL) {
- printk(KERN_ERR "ubd_config failed to strdup string\n");
- ret = 1;
- goto out;
+ *error_out = "Failed to allocate memory";
+ return -ENOMEM;
}
- ret = ubd_setup_common(str, &n);
- if (ret) {
- ret = -1;
+
+ ret = ubd_setup_common(str, &n, error_out);
+ if (ret)
goto err_free;
- }
+
if (n == -1) {
ret = 0;
goto err_free;
}
mutex_lock(&ubd_lock);
- ret = ubd_add(n);
+ ret = ubd_add(n, error_out);
if (ret)
ubd_devs[n].file = NULL;
mutex_unlock(&ubd_lock);
@@ -777,7 +786,7 @@ static int ubd_id(char **str, int *start_out, int *end_out)
return n;
}
-static int ubd_remove(int n)
+static int ubd_remove(int n, char **error_out)
{
struct ubd *ubd_dev;
int err = -ENODEV;
@@ -815,7 +824,9 @@ out:
return err;
}
-/* All these are called by mconsole in process context and without ubd-specific locks. */
+/* All these are called by mconsole in process context and without
+ * ubd-specific locks.
+ */
static struct mc_device ubd_mc = {
.name = "ubd",
.config = ubd_config,
@@ -851,7 +862,8 @@ static struct platform_driver ubd_driver = {
static int __init ubd_init(void)
{
- int i;
+ char *error;
+ int i, err;
if (register_blkdev(MAJOR_NR, "ubd"))
return -1;
@@ -870,8 +882,12 @@ static int __init ubd_init(void)
return -1;
}
platform_driver_register(&ubd_driver);
- for (i = 0; i < MAX_DEV; i++)
- ubd_add(i);
+ for (i = 0; i < MAX_DEV; i++){
+ err = ubd_add(i, &error);
+ if(err)
+ printk(KERN_ERR "Failed to initialize ubd device %d :"
+ "%s\n", i, error);
+ }
return 0;
}