i2c: __must_check fixes (chip drivers)

i2c: __must_check fixes (chip drivers)

Check for error on sysfs file creation.
Delete sysfs files on device removal.

The approach taken for the most complex case (pcf8591) is similar to
what Mark M. Hoffman proposed for hardware monitoring chip drivers.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <bgardner@wabtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 97 insertions, 27 deletions

diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 13c108269a6d..cec3a0c3894d 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -209,10 +209,14 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
         }
 
         /* create the sysfs eeprom file */
-        sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
+        err = sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
+        if (err)
+                goto exit_detach;
 
         return 0;
 
+exit_detach:
+        i2c_detach_client(new_client);
 exit_kfree:
         kfree(data);
 exit:
@@ -223,6 +227,8 @@ static int eeprom_detach_client(struct i2c_client *client)
 {
         int err;
 
+        sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
+
         err = i2c_detach_client(client);
         if (err)
                 return err;
diff --git a/drivers/i2c/chips/max6875.c b/drivers/i2c/chips/max6875.c
index 88d2ddee4490..76645c142977 100644
--- a/drivers/i2c/chips/max6875.c
+++ b/drivers/i2c/chips/max6875.c
@@ -199,8 +199,7 @@ static int max6875_detect(struct i2c_adapter *adapter, int address, int kind)
         mutex_init(&data->update_lock);
 
         /* Init fake client data */
-        /* set the client data to the i2c_client so that it will get freed */
-        i2c_set_clientdata(fake_client, fake_client);
+        i2c_set_clientdata(fake_client, NULL);
         fake_client->addr = address | 1;
         fake_client->adapter = adapter;
         fake_client->driver = &max6875_driver;
@@ -214,13 +213,17 @@ static int max6875_detect(struct i2c_adapter *adapter, int address, int kind)
                 goto exit_kfree2;
 
         if ((err = i2c_attach_client(fake_client)) != 0)
-                goto exit_detach;
+                goto exit_detach1;
 
-        sysfs_create_bin_file(&real_client->dev.kobj, &user_eeprom_attr);
+        err = sysfs_create_bin_file(&real_client->dev.kobj, &user_eeprom_attr);
+        if (err)
+                goto exit_detach2;
 
         return 0;
 
-exit_detach:
+exit_detach2:
+        i2c_detach_client(fake_client);
+exit_detach1:
         i2c_detach_client(real_client);
 exit_kfree2:
         kfree(fake_client);
@@ -229,14 +232,24 @@ exit_kfree1:
         return err;
 }
 
+/* Will be called for both the real client and the fake client */
 static int max6875_detach_client(struct i2c_client *client)
 {
         int err;
+        struct max6875_data *data = i2c_get_clientdata(client);
+
+        /* data is NULL for the fake client */
+        if (data)
+                sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr);
 
         err = i2c_detach_client(client);
         if (err)
                 return err;
-        kfree(i2c_get_clientdata(client));
+
+        if (data)               /* real client */
+                kfree(data);
+        else                    /* fake client */
+                kfree(client);
         return 0;
 }
 
diff --git a/drivers/i2c/chips/pca9539.c b/drivers/i2c/chips/pca9539.c
index cb22280cdd27..f43c4e79b55e 100644
--- a/drivers/i2c/chips/pca9539.c
+++ b/drivers/i2c/chips/pca9539.c
@@ -148,11 +148,16 @@ static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind)
         if ((err = i2c_attach_client(new_client)))
                 goto exit_kfree;
 
-        /* Register sysfs hooks (don't care about failure) */
-        sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group);
+        /* Register sysfs hooks */
+        err = sysfs_create_group(&new_client->dev.kobj,
+                                 &pca9539_defattr_group);
+        if (err)
+                goto exit_detach;
 
         return 0;
 
+exit_detach:
+        i2c_detach_client(new_client);
 exit_kfree:
         kfree(data);
 exit:
@@ -163,6 +168,8 @@ static int pca9539_detach_client(struct i2c_client *client)
 {
         int err;
 
+        sysfs_remove_group(&client->dev.kobj, &pca9539_defattr_group);
+
         if ((err = i2c_detach_client(client)))
                 return err;
 
diff --git a/drivers/i2c/chips/pcf8574.c b/drivers/i2c/chips/pcf8574.c
index c3e6449c4481..32b25427eaba 100644
--- a/drivers/i2c/chips/pcf8574.c
+++ b/drivers/i2c/chips/pcf8574.c
@@ -105,6 +105,16 @@ static ssize_t set_write(struct device *dev, struct device_attribute *attr, cons
 
 static DEVICE_ATTR(write, S_IWUSR | S_IRUGO, show_write, set_write);
 
+static struct attribute *pcf8574_attributes[] = {
+        &dev_attr_read.attr,
+        &dev_attr_write.attr,
+        NULL
+};
+
+static const struct attribute_group pcf8574_attr_group = {
+        .attrs = pcf8574_attributes,
+};
+
 /*
  * Real code
  */
@@ -166,13 +176,13 @@ static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
         pcf8574_init_client(new_client);
 
         /* Register sysfs hooks */
-        device_create_file(&new_client->dev, &dev_attr_read);
-        device_create_file(&new_client->dev, &dev_attr_write);
+        err = sysfs_create_group(&new_client->dev.kobj, &pcf8574_attr_group);
+        if (err)
+                goto exit_detach;
         return 0;
 
-/* OK, this is not exactly good programming practice, usually. But it is
-   very code-efficient in this case. */
-
+      exit_detach:
+        i2c_detach_client(new_client);
       exit_free:
         kfree(data);
       exit:
@@ -183,6 +193,8 @@ static int pcf8574_detach_client(struct i2c_client *client)
 {
         int err;
 
+        sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group);
+
         if ((err = i2c_detach_client(client)))
                 return err;
 
diff --git a/drivers/i2c/chips/pcf8591.c b/drivers/i2c/chips/pcf8591.c
index 925a6b371fd2..4dc36376eb32 100644
--- a/drivers/i2c/chips/pcf8591.c
+++ b/drivers/i2c/chips/pcf8591.c
@@ -158,6 +158,28 @@ static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr
 static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, 
                    show_out0_enable, set_out0_enable);
 
+static struct attribute *pcf8591_attributes[] = {
+        &dev_attr_out0_enable.attr,
+        &dev_attr_out0_output.attr,
+        &dev_attr_in0_input.attr,
+        &dev_attr_in1_input.attr,
+        NULL
+};
+
+static const struct attribute_group pcf8591_attr_group = {
+        .attrs = pcf8591_attributes,
+};
+
+static struct attribute *pcf8591_attributes_opt[] = {
+        &dev_attr_in2_input.attr,
+        &dev_attr_in3_input.attr,
+        NULL
+};
+
+static const struct attribute_group pcf8591_attr_group_opt = {
+        .attrs = pcf8591_attributes_opt,
+};
+
 /*
  * Real code
  */
@@ -211,24 +233,31 @@ static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
         pcf8591_init_client(new_client);
 
         /* Register sysfs hooks */
-        device_create_file(&new_client->dev, &dev_attr_out0_enable);
-        device_create_file(&new_client->dev, &dev_attr_out0_output);
-        device_create_file(&new_client->dev, &dev_attr_in0_input);
-        device_create_file(&new_client->dev, &dev_attr_in1_input);
+        err = sysfs_create_group(&new_client->dev.kobj, &pcf8591_attr_group);
+        if (err)
+                goto exit_detach;
 
         /* Register input2 if not in "two differential inputs" mode */
-        if (input_mode != 3 )
-                device_create_file(&new_client->dev, &dev_attr_in2_input);
-                
+        if (input_mode != 3) {
+                if ((err = device_create_file(&new_client->dev,
+                                              &dev_attr_in2_input)))
+                        goto exit_sysfs_remove;
+        }
+
         /* Register input3 only in "four single ended inputs" mode */
-        if (input_mode == 0)
-                device_create_file(&new_client->dev, &dev_attr_in3_input);
-        
+        if (input_mode == 0) {
+                if ((err = device_create_file(&new_client->dev,
+                                              &dev_attr_in3_input)))
+                        goto exit_sysfs_remove;
+        }
+
         return 0;
-        
-        /* OK, this is not exactly good programming practice, usually. But it is
-           very code-efficient in this case. */
 
+exit_sysfs_remove:
+        sysfs_remove_group(&new_client->dev.kobj, &pcf8591_attr_group_opt);
+        sysfs_remove_group(&new_client->dev.kobj, &pcf8591_attr_group);
+exit_detach:
+        i2c_detach_client(new_client);
 exit_kfree:
         kfree(data);
 exit:
@@ -239,6 +268,9 @@ static int pcf8591_detach_client(struct i2c_client *client)
 {
         int err;
 
+        sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
+        sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
+
         if ((err = i2c_detach_client(client)))
                 return err;