[PATCH] uml: return hotplug errors to host
I noticed that errors happening while hotplugging devices from the host were
never returned back to the mconsole client. In some cases, success was
returned instead of even an information-free error.
This patch cleans that up by having the low-level configuration code pass back
an error string along with an error code. At the top level, which knows
whether it is early boot time or responding to an mconsole request, the string
is printk'd or returned to the mconsole client.
There are also whitespace and trivial code cleanups in the surrounding code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 7d4190e..4e7e3cf 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,44 +19,11 @@
#include "line.h"
#include "os.h"
-/* XXX: could well be moved to somewhere else, if needed. */
-static int my_printf(const char * fmt, ...)
- __attribute__ ((format (printf, 1, 2)));
-
-static int my_printf(const char * fmt, ...)
-{
- /* Yes, can be called on atomic context.*/
- char *buf = kmalloc(4096, GFP_ATOMIC);
- va_list args;
- int r;
-
- if (!buf) {
- /* We print directly fmt.
- * Yes, yes, yes, feel free to complain. */
- r = strlen(fmt);
- } else {
- va_start(args, fmt);
- r = vsprintf(buf, fmt, args);
- va_end(args);
- fmt = buf;
- }
-
- if (r)
- r = os_write_file(1, fmt, r);
- return r;
-
-}
-
#ifdef CONFIG_NOCONFIG_CHAN
-/* Despite its name, there's no added trailing newline. */
-static int my_puts(const char * buf)
+static void *not_configged_init(char *str, int device,
+ const struct chan_opts *opts)
{
- return os_write_file(1, buf, strlen(buf));
-}
-
-static void *not_configged_init(char *str, int device, struct chan_opts *opts)
-{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return NULL;
}
@@ -64,34 +31,34 @@
static int not_configged_open(int input, int output, int primary, void *data,
char **dev_out)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return -ENODEV;
}
static void not_configged_close(int fd, void *data)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
}
static int not_configged_read(int fd, char *c_out, void *data)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
static int not_configged_write(int fd, const char *buf, int len, void *data)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
static int not_configged_console_write(int fd, const char *buf, int len)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
@@ -99,14 +66,14 @@
static int not_configged_window_size(int fd, void *data, unsigned short *rows,
unsigned short *cols)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
return -ENODEV;
}
static void not_configged_free(void *data)
{
- my_puts("Using a channel type which is configured out of "
+ printk("Using a channel type which is configured out of "
"UML\n");
}
@@ -534,7 +501,7 @@
};
static struct chan *parse_chan(struct line *line, char *str, int device,
- const struct chan_opts *opts)
+ const struct chan_opts *opts, char **error_out)
{
const struct chan_type *entry;
const struct chan_ops *ops;
@@ -553,19 +520,21 @@
}
}
if(ops == NULL){
- my_printf("parse_chan couldn't parse \"%s\"\n",
- str);
+ *error_out = "No match for configured backends";
return NULL;
}
- if(ops->init == NULL)
- return NULL;
+
data = (*ops->init)(str, device, opts);
- if(data == NULL)
+ if(data == NULL){
+ *error_out = "Configuration failed";
return NULL;
+ }
chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
- if(chan == NULL)
+ if(chan == NULL){
+ *error_out = "Memory allocation failed";
return NULL;
+ }
*chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
.free_list =
LIST_HEAD_INIT(chan->free_list),
@@ -582,7 +551,7 @@
}
int parse_chan_pair(char *str, struct line *line, int device,
- const struct chan_opts *opts)
+ const struct chan_opts *opts, char **error_out)
{
struct list_head *chans = &line->chan_list;
struct chan *new, *chan;
@@ -599,14 +568,14 @@
in = str;
*out = '\0';
out++;
- new = parse_chan(line, in, device, opts);
+ new = parse_chan(line, in, device, opts, error_out);
if(new == NULL)
return -1;
new->input = 1;
list_add(&new->list, chans);
- new = parse_chan(line, out, device, opts);
+ new = parse_chan(line, out, device, opts, error_out);
if(new == NULL)
return -1;
@@ -614,7 +583,7 @@
new->output = 1;
}
else {
- new = parse_chan(line, str, device, opts);
+ new = parse_chan(line, str, device, opts, error_out);
if(new == NULL)
return -1;
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 799fca3..e620ed46 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -549,14 +549,16 @@
close_chan(&lines[i].chan_list, 0);
}
-static void setup_one_line(struct line *lines, int n, char *init, int init_prio)
+static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
+ char **error_out)
{
struct line *line = &lines[n];
+ int err = -EINVAL;
spin_lock(&line->count_lock);
if(line->tty != NULL){
- printk("line_setup - device %d is open\n", n);
+ *error_out = "Device is already open";
goto out;
}
@@ -569,18 +571,22 @@
line->valid = 1;
}
}
+ err = 0;
out:
spin_unlock(&line->count_lock);
+ return err;
}
/* Common setup code for both startup command line and mconsole initialization.
* @lines contains the array (of size @num) to modify;
* @init is the setup string;
+ * @error_out is an error string in the case of failure;
*/
-int line_setup(struct line *lines, unsigned int num, char *init)
+int line_setup(struct line *lines, unsigned int num, char *init,
+ char **error_out)
{
- int i, n;
+ int i, n, err;
char *end;
if(*init == '=') {
@@ -591,52 +597,56 @@
else {
n = simple_strtoul(init, &end, 0);
if(*end != '='){
- printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
- init);
- return 0;
+ *error_out = "Couldn't parse device number";
+ return -EINVAL;
}
init = end;
}
init++;
if (n >= (signed int) num) {
- printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
- n, num - 1);
- return 0;
+ *error_out = "Device number out of range";
+ return -EINVAL;
}
- else if (n >= 0)
- setup_one_line(lines, n, init, INIT_ONE);
+ else if (n >= 0){
+ err = setup_one_line(lines, n, init, INIT_ONE, error_out);
+ if(err)
+ return err;
+ }
else {
- for(i = 0; i < num; i++)
- setup_one_line(lines, i, init, INIT_ALL);
+ for(i = 0; i < num; i++){
+ err = setup_one_line(lines, i, init, INIT_ALL,
+ error_out);
+ if(err)
+ return err;
+ }
}
return n == -1 ? num : n;
}
int line_config(struct line *lines, unsigned int num, char *str,
- const struct chan_opts *opts)
+ const struct chan_opts *opts, char **error_out)
{
struct line *line;
char *new;
int n;
if(*str == '='){
- printk("line_config - can't configure all devices from "
- "mconsole\n");
- return 1;
+ *error_out = "Can't configure all devices from mconsole";
+ return -EINVAL;
}
new = kstrdup(str, GFP_KERNEL);
if(new == NULL){
- printk("line_config - kstrdup failed\n");
- return 1;
+ *error_out = "Failed to allocate memory";
+ return -ENOMEM;
}
- n = line_setup(lines, num, new);
+ n = line_setup(lines, num, new, error_out);
if(n < 0)
- return 1;
+ return n;
line = &lines[n];
- return parse_chan_pair(line->init_str, line, n, opts);
+ return parse_chan_pair(line->init_str, line, n, opts, error_out);
}
int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
@@ -685,13 +695,13 @@
return n;
}
-int line_remove(struct line *lines, unsigned int num, int n)
+int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
{
int err;
char config[sizeof("conxxxx=none\0")];
sprintf(config, "%d=none", n);
- err = line_setup(lines, num, config);
+ err = line_setup(lines, num, config, error_out);
if(err >= 0)
err = 0;
return err;
@@ -740,6 +750,7 @@
void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
{
struct line *line;
+ char *error;
int i;
for(i = 0; i < nlines; i++){
@@ -754,8 +765,9 @@
if(line->init_str == NULL)
printk("lines_init - kstrdup returned NULL\n");
- if(parse_chan_pair(line->init_str, line, i, opts)){
- printk("parse_chan_pair failed for device %d\n", i);
+ if(parse_chan_pair(line->init_str, line, i, opts, &error)){
+ printk("parse_chan_pair failed for device %d : %s\n",
+ i, error);
line->valid = 0;
}
}
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 96f0189..832d5c7 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -371,14 +371,16 @@
static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
static int unplug_index = UNPLUGGED_PER_PAGE;
-static int mem_config(char *str)
+static int mem_config(char *str, char **error_out)
{
unsigned long long diff;
int err = -EINVAL, i, add;
char *ret;
- if(str[0] != '=')
+ if(str[0] != '='){
+ *error_out = "Expected '=' after 'mem'";
goto out;
+ }
str++;
if(str[0] == '-')
@@ -386,12 +388,17 @@
else if(str[0] == '+'){
add = 1;
}
- else goto out;
+ else {
+ *error_out = "Expected increment to start with '-' or '+'";
+ goto out;
+ }
str++;
diff = memparse(str, &ret);
- if(*ret != '\0')
+ if(*ret != '\0'){
+ *error_out = "Failed to parse memory increment";
goto out;
+ }
diff /= PAGE_SIZE;
@@ -435,11 +442,14 @@
unplugged = list_entry(entry,
struct unplugged_pages,
list);
- unplugged->pages[unplug_index++] = addr;
err = os_drop_memory(addr, PAGE_SIZE);
- if(err)
+ if(err){
printk("Failed to release memory - "
"errno = %d\n", err);
+ *error_out = "Failed to release memory";
+ goto out;
+ }
+ unplugged->pages[unplug_index++] = addr;
}
unplugged_pages_count++;
@@ -470,8 +480,9 @@
return 0;
}
-static int mem_remove(int n)
+static int mem_remove(int n, char **error_out)
{
+ *error_out = "Memory doesn't support the remove operation";
return -EBUSY;
}
@@ -542,7 +553,7 @@
void mconsole_config(struct mc_request *req)
{
struct mc_device *dev;
- char *ptr = req->request.data, *name;
+ char *ptr = req->request.data, *name, *error_string = "";
int err;
ptr += strlen("config");
@@ -559,8 +570,8 @@
ptr++;
if(*ptr == '='){
- err = (*dev->config)(name);
- mconsole_reply(req, "", err, 0);
+ err = (*dev->config)(name, &error_string);
+ mconsole_reply(req, error_string, err, 0);
}
else mconsole_get_config(dev->get_config, req, name);
}
@@ -595,13 +606,16 @@
goto out;
}
- err = (*dev->remove)(n);
+ err_msg = NULL;
+ err = (*dev->remove)(n, &err_msg);
switch(err){
case -ENODEV:
- err_msg = "Device doesn't exist";
+ if(err_msg == NULL)
+ err_msg = "Device doesn't exist";
break;
case -EBUSY:
- err_msg = "Device is currently open";
+ if(err_msg == NULL)
+ err_msg = "Device is currently open";
break;
default:
break;
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index afe3d42..07e839e 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
* James Leu (jleu@mindspring.net).
* Copyright (C) 2001 by various other people who didn't put their name here.
* Licensed under the GPL.
@@ -91,8 +91,8 @@
spin_lock(&lp->lock);
while((err = uml_net_rx(dev)) > 0) ;
if(err < 0) {
- printk(KERN_ERR
- "Device '%s' read returned %d, shutting it down\n",
+ printk(KERN_ERR
+ "Device '%s' read returned %d, shutting it down\n",
dev->name, err);
/* dev_close can't be called in interrupt context, and takes
* again lp->lock.
@@ -159,7 +159,7 @@
static int uml_net_close(struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
-
+
netif_stop_queue(dev);
free_irq(dev->irq, dev);
@@ -194,7 +194,7 @@
/* this is normally done in the interrupt when tx finishes */
netif_wake_queue(dev);
- }
+ }
else if(len == 0){
netif_start_queue(dev);
lp->stats.tx_dropped++;
@@ -333,7 +333,7 @@
struct uml_net_private *lp;
int save, err, size;
- size = transport->private_size + sizeof(struct uml_net_private) +
+ size = transport->private_size + sizeof(struct uml_net_private) +
sizeof(((struct uml_net_private *) 0)->user);
device = kzalloc(sizeof(*device), GFP_KERNEL);
@@ -438,7 +438,7 @@
lp->tl.function = uml_net_user_timer_expire;
memcpy(lp->mac, device->mac, sizeof(lp->mac));
- if (transport->user->init)
+ if (transport->user->init)
(*transport->user->init)(&lp->user, dev);
set_ether_mac(dev, device->mac);
@@ -463,35 +463,33 @@
return(device);
}
-static int eth_parse(char *str, int *index_out, char **str_out)
+static int eth_parse(char *str, int *index_out, char **str_out,
+ char **error_out)
{
char *end;
- int n;
+ int n, err = -EINVAL;;
n = simple_strtoul(str, &end, 0);
if(end == str){
- printk(KERN_ERR "eth_setup: Failed to parse '%s'\n", str);
- return(1);
+ *error_out = "Bad device number";
+ return err;
}
- if(n < 0){
- printk(KERN_ERR "eth_setup: device %d is negative\n", n);
- return(1);
- }
+
str = end;
if(*str != '='){
- printk(KERN_ERR
- "eth_setup: expected '=' after device number\n");
- return(1);
+ *error_out = "Expected '=' after device number";
+ return err;
}
+
str++;
if(find_device(n)){
- printk(KERN_ERR "eth_setup: Device %d already configured\n",
- n);
- return(1);
+ *error_out = "Device already configured";
+ return err;
}
- if(index_out) *index_out = n;
+
+ *index_out = n;
*str_out = str;
- return(0);
+ return 0;
}
struct eth_init {
@@ -581,11 +579,15 @@
static int eth_setup(char *str)
{
struct eth_init *new;
+ char *error;
int n, err;
- err = eth_parse(str, &n, &str);
- if(err)
+ err = eth_parse(str, &n, &str, &error);
+ if(err){
+ printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
+ str, error);
return 1;
+ }
new = alloc_bootmem(sizeof(*new));
if (new == NULL){
@@ -619,26 +621,30 @@
if(eth_setup_common(eth->init, eth->index))
list_del(ð->list);
}
-
+
return(1);
}
__initcall(eth_init);
#endif
-static int net_config(char *str)
+static int net_config(char *str, char **error_out)
{
int n, err;
- err = eth_parse(str, &n, &str);
- if(err) return(err);
+ err = eth_parse(str, &n, &str, error_out);
+ if(err)
+ return err;
+ /* This string is broken up and the pieces used by the underlying
+ * driver. So, it is freed only if eth_setup_common fails.
+ */
str = kstrdup(str, GFP_KERNEL);
if(str == NULL){
- printk(KERN_ERR "net_config failed to strdup string\n");
- return(-1);
+ *error_out = "net_config failed to strdup string";
+ return -ENOMEM;
}
err = !eth_setup_common(str, n);
- if(err)
+ if(err)
kfree(str);
return(err);
}
@@ -658,7 +664,7 @@
return n;
}
-static int net_remove(int n)
+static int net_remove(int n, char **error_out)
{
struct uml_net *device;
struct net_device *dev;
@@ -727,7 +733,7 @@
static int uml_net_init(void)
{
struct list_head *ele;
- struct uml_net_private *lp;
+ struct uml_net_private *lp;
struct in_device *ip;
struct in_ifaddr *in;
@@ -747,7 +753,7 @@
uml_inetaddr_event(NULL, NETDEV_UP, in);
in = in->ifa_next;
}
- }
+ }
return(0);
}
@@ -783,8 +789,8 @@
return(skb);
}
-void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
- void *),
+void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
+ void *),
void *arg)
{
struct net_device *dev = d;
@@ -809,11 +815,11 @@
struct in_ifaddr *in;
__be32 *mask_out = m;
- if(ip == NULL)
+ if(ip == NULL)
return(1);
in = ip->ifa_list;
- if(in == NULL)
+ if(in == NULL)
return(1);
*mask_out = in->ifa_mask;
@@ -835,7 +841,7 @@
free_pages((unsigned long) buffer, 0);
}
-int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
+int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
char **gate_addr)
{
char *remain;
@@ -854,14 +860,3 @@
{
return(eth_type_trans(skb, skb->dev));
}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index ed9c590..1e82430 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -46,9 +46,9 @@
.in_kernel = 1,
};
-static int ssl_config(char *str);
+static int ssl_config(char *str, char **error_out);
static int ssl_get_config(char *dev, char *str, int size, char **error_out);
-static int ssl_remove(int n);
+static int ssl_remove(int n, char **error_out);
static struct line_driver driver = {
.name = "UML serial line",
@@ -80,9 +80,10 @@
static struct lines lines = LINES_INIT(NR_PORTS);
-static int ssl_config(char *str)
+static int ssl_config(char *str, char **error_out)
{
- return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts);
+ return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
+ error_out);
}
static int ssl_get_config(char *dev, char *str, int size, char **error_out)
@@ -91,9 +92,10 @@
size, error_out);
}
-static int ssl_remove(int n)
+static int ssl_remove(int n, char **error_out)
{
- return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n);
+ return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
+ error_out);
}
static int ssl_open(struct tty_struct *tty, struct file *filp)
@@ -212,7 +214,15 @@
static int ssl_chan_setup(char *str)
{
- return line_setup(serial_lines, ARRAY_SIZE(serial_lines), str);
+ char *error;
+ int ret;
+
+ ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
+ if(ret < 0)
+ printk(KERN_ERR "Failed to set up serial line with "
+ "configuration string \"%s\" : %s\n", str, error);
+
+ return 1;
}
__setup("ssl", ssl_chan_setup);
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 9b2dd0b..3cbfe3a 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -52,9 +52,9 @@
.in_kernel = 1,
};
-static int con_config(char *str);
+static int con_config(char *str, char **error_out);
static int con_get_config(char *dev, char *str, int size, char **error_out);
-static int con_remove(int n);
+static int con_remove(int n, char **con_remove);
static struct line_driver driver = {
.name = "UML console",
@@ -87,9 +87,9 @@
[ 1 ... MAX_TTYS - 1 ] =
LINE_INIT(CONFIG_CON_CHAN, &driver) };
-static int con_config(char *str)
+static int con_config(char *str, char **error_out)
{
- return line_config(vts, ARRAY_SIZE(vts), str, &opts);
+ return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
}
static int con_get_config(char *dev, char *str, int size, char **error_out)
@@ -97,9 +97,9 @@
return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
}
-static int con_remove(int n)
+static int con_remove(int n, char **error_out)
{
- return line_remove(vts, ARRAY_SIZE(vts), n);
+ return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
}
static int con_open(struct tty_struct *tty, struct file *filp)
@@ -192,7 +192,15 @@
static int console_chan_setup(char *str)
{
- return line_setup(vts, ARRAY_SIZE(vts), str);
+ char *error;
+ int ret;
+
+ ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
+ if(ret < 0)
+ printk(KERN_ERR "Failed to set up console with "
+ "configuration string \"%s\" : %s\n", str, error);
+
+ return 1;
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 49c047b..f4db97e 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -286,7 +286,7 @@
* 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 @@
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 @@
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 @@
" 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 @@
#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 @@
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 @@
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 @@
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 int __init ubd_init(void)
{
- int i;
+ char *error;
+ int i, err;
if (register_blkdev(MAJOR_NR, "ubd"))
return -1;
@@ -870,8 +882,12 @@
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;
}