From 870823e629ea194e6cf8e82a9694ac62cad49512 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Oct 2015 15:32:37 +0200 Subject: configfs: add show and store methods to struct configfs_attribute Add methods to struct configfs_attribute to directly show and store attributes without adding boilerplate code to every user. In addition to the methods this also adds 3 helper macros to define read/write, read-only and write-only attributes with a single line of code. Signed-off-by: Christoph Hellwig Reviewed-by: Nicholas Bellinger Acked-by: Greg Kroah-Hartman Signed-off-by: Nicholas Bellinger --- include/linux/configfs.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux') diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 63a36e89d0eb..85e9956a86de 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -125,8 +125,35 @@ struct configfs_attribute { const char *ca_name; struct module *ca_owner; umode_t ca_mode; + ssize_t (*show)(struct config_item *, char *); + ssize_t (*store)(struct config_item *, const char *, size_t); }; +#define CONFIGFS_ATTR(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IRUGO | S_IWUSR, \ + .ca_owner = THIS_MODULE, \ + .show = _pfx##_name##_show, \ + .store = _pfx##_name##_store, \ +} + +#define CONFIGFS_ATTR_RO(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IRUGO, \ + .ca_owner = THIS_MODULE, \ + .show = _pfx##_name##_show, \ +} + +#define CONFIGFS_ATTR_WO(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IWUSR, \ + .ca_owner = THIS_MODULE, \ + .store = _pfx##_name##_store, \ +} + /* * Users often need to create attribute structures for their configurable * attributes, containing a configfs_attribute member and function pointers -- cgit v1.2.3 From 45b6a73f62ebcf3ff067895fb8030e67f4c7b67f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Oct 2015 15:32:38 +0200 Subject: usb-gadget: use per-attribute show and store methods To simplify the configfs interface and remove boilerplate code that also causes binary bloat. Signed-off-by: Christoph Hellwig Reviewed-by: Andrzej Pietrasiewicz Acked-by: Felipe Balbi Signed-off-by: Nicholas Bellinger --- drivers/usb/gadget/configfs.c | 295 ++++++++++++++---------------------- include/linux/usb/gadget_configfs.h | 19 +-- 2 files changed, 118 insertions(+), 196 deletions(-) (limited to 'include/linux') diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index 294eb74fb078..163d305e1200 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -64,6 +64,11 @@ struct gadget_info { char qw_sign[OS_STRING_QW_SIGN_LEN]; }; +static inline struct gadget_info *to_gadget_info(struct config_item *item) +{ + return container_of(to_config_group(item), struct gadget_info, group); +} + struct config_usb_cfg { struct config_group group; struct config_group strings_group; @@ -74,6 +79,12 @@ struct config_usb_cfg { struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1]; }; +static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item) +{ + return container_of(to_config_group(item), struct config_usb_cfg, + group); +} + struct gadget_strings { struct usb_gadget_strings stringtab_dev; struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX]; @@ -117,32 +128,25 @@ static int usb_string_copy(const char *s, char **s_copy) return 0; } -CONFIGFS_ATTR_STRUCT(gadget_info); -CONFIGFS_ATTR_STRUCT(config_usb_cfg); - -#define GI_DEVICE_DESC_ITEM_ATTR(name) \ - static struct gadget_info_attribute gadget_cdev_desc_##name = \ - __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, \ - gadget_dev_desc_##name##_show, \ - gadget_dev_desc_##name##_store) - #define GI_DEVICE_DESC_SIMPLE_R_u8(__name) \ - static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \ +static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \ char *page) \ { \ - return sprintf(page, "0x%02x\n", gi->cdev.desc.__name); \ + return sprintf(page, "0x%02x\n", \ + to_gadget_info(item)->cdev.desc.__name); \ } #define GI_DEVICE_DESC_SIMPLE_R_u16(__name) \ - static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \ +static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \ char *page) \ { \ - return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \ + return sprintf(page, "0x%04x\n", \ + le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \ } #define GI_DEVICE_DESC_SIMPLE_W_u8(_name) \ - static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \ +static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \ const char *page, size_t len) \ { \ u8 val; \ @@ -150,12 +154,12 @@ CONFIGFS_ATTR_STRUCT(config_usb_cfg); ret = kstrtou8(page, 0, &val); \ if (ret) \ return ret; \ - gi->cdev.desc._name = val; \ + to_gadget_info(item)->cdev.desc._name = val; \ return len; \ } #define GI_DEVICE_DESC_SIMPLE_W_u16(_name) \ - static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \ +static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \ const char *page, size_t len) \ { \ u16 val; \ @@ -163,7 +167,7 @@ CONFIGFS_ATTR_STRUCT(config_usb_cfg); ret = kstrtou16(page, 0, &val); \ if (ret) \ return ret; \ - gi->cdev.desc._name = cpu_to_le16p(&val); \ + to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val); \ return len; \ } @@ -193,7 +197,7 @@ static ssize_t is_valid_bcd(u16 bcd_val) return 0; } -static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi, +static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item, const char *page, size_t len) { u16 bcdDevice; @@ -206,11 +210,11 @@ static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi, if (ret) return ret; - gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice); + to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice); return len; } -static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi, +static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item, const char *page, size_t len) { u16 bcdUSB; @@ -223,13 +227,13 @@ static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi, if (ret) return ret; - gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB); + to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB); return len; } -static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page) +static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page) { - return sprintf(page, "%s\n", gi->udc_name ?: ""); + return sprintf(page, "%s\n", to_gadget_info(item)->udc_name ?: ""); } static int unregister_gadget(struct gadget_info *gi) @@ -247,9 +251,10 @@ static int unregister_gadget(struct gadget_info *gi) return 0; } -static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi, +static ssize_t gadget_dev_desc_UDC_store(struct config_item *item, const char *page, size_t len) { + struct gadget_info *gi = to_gadget_info(item); char *name; int ret; @@ -283,34 +288,29 @@ err: return ret; } -GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass); -GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass); -GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol); -GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0); -GI_DEVICE_DESC_ITEM_ATTR(idVendor); -GI_DEVICE_DESC_ITEM_ATTR(idProduct); -GI_DEVICE_DESC_ITEM_ATTR(bcdDevice); -GI_DEVICE_DESC_ITEM_ATTR(bcdUSB); -GI_DEVICE_DESC_ITEM_ATTR(UDC); +CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass); +CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass); +CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol); +CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0); +CONFIGFS_ATTR(gadget_dev_desc_, idVendor); +CONFIGFS_ATTR(gadget_dev_desc_, idProduct); +CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice); +CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB); +CONFIGFS_ATTR(gadget_dev_desc_, UDC); static struct configfs_attribute *gadget_root_attrs[] = { - &gadget_cdev_desc_bDeviceClass.attr, - &gadget_cdev_desc_bDeviceSubClass.attr, - &gadget_cdev_desc_bDeviceProtocol.attr, - &gadget_cdev_desc_bMaxPacketSize0.attr, - &gadget_cdev_desc_idVendor.attr, - &gadget_cdev_desc_idProduct.attr, - &gadget_cdev_desc_bcdDevice.attr, - &gadget_cdev_desc_bcdUSB.attr, - &gadget_cdev_desc_UDC.attr, + &gadget_dev_desc_attr_bDeviceClass, + &gadget_dev_desc_attr_bDeviceSubClass, + &gadget_dev_desc_attr_bDeviceProtocol, + &gadget_dev_desc_attr_bMaxPacketSize0, + &gadget_dev_desc_attr_idVendor, + &gadget_dev_desc_attr_idProduct, + &gadget_dev_desc_attr_bcdDevice, + &gadget_dev_desc_attr_bcdUSB, + &gadget_dev_desc_attr_UDC, NULL, }; -static inline struct gadget_info *to_gadget_info(struct config_item *item) -{ - return container_of(to_config_group(item), struct gadget_info, group); -} - static inline struct gadget_strings *to_gadget_strings(struct config_item *item) { return container_of(to_config_group(item), struct gadget_strings, @@ -324,12 +324,6 @@ static inline struct gadget_config_name *to_gadget_config_name( group); } -static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item) -{ - return container_of(to_config_group(item), struct config_usb_cfg, - group); -} - static inline struct usb_function_instance *to_usb_function_instance( struct config_item *item) { @@ -348,12 +342,8 @@ static void gadget_info_attr_release(struct config_item *item) kfree(gi); } -CONFIGFS_ATTR_OPS(gadget_info); - static struct configfs_item_operations gadget_root_item_ops = { .release = gadget_info_attr_release, - .show_attribute = gadget_info_attr_show, - .store_attribute = gadget_info_attr_store, }; static void gadget_config_attr_release(struct config_item *item) @@ -454,24 +444,20 @@ static int config_usb_cfg_unlink( return 0; } -CONFIGFS_ATTR_OPS(config_usb_cfg); - static struct configfs_item_operations gadget_config_item_ops = { .release = gadget_config_attr_release, - .show_attribute = config_usb_cfg_attr_show, - .store_attribute = config_usb_cfg_attr_store, .allow_link = config_usb_cfg_link, .drop_link = config_usb_cfg_unlink, }; -static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg, +static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item, char *page) { - return sprintf(page, "%u\n", cfg->c.MaxPower); + return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower); } -static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg, +static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item, const char *page, size_t len) { u16 val; @@ -481,17 +467,18 @@ static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg, return ret; if (DIV_ROUND_UP(val, 8) > 0xff) return -ERANGE; - cfg->c.MaxPower = val; + to_config_usb_cfg(item)->c.MaxPower = val; return len; } -static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg, +static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item, char *page) { - return sprintf(page, "0x%02x\n", cfg->c.bmAttributes); + return sprintf(page, "0x%02x\n", + to_config_usb_cfg(item)->c.bmAttributes); } -static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg, +static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item, const char *page, size_t len) { u8 val; @@ -504,22 +491,16 @@ static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg, if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER | USB_CONFIG_ATT_WAKEUP)) return -EINVAL; - cfg->c.bmAttributes = val; + to_config_usb_cfg(item)->c.bmAttributes = val; return len; } -#define CFG_CONFIG_DESC_ITEM_ATTR(name) \ - static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \ - __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, \ - gadget_config_desc_##name##_show, \ - gadget_config_desc_##name##_store) - -CFG_CONFIG_DESC_ITEM_ATTR(MaxPower); -CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes); +CONFIGFS_ATTR(gadget_config_desc_, MaxPower); +CONFIGFS_ATTR(gadget_config_desc_, bmAttributes); static struct configfs_attribute *gadget_config_attrs[] = { - &gadget_usb_cfg_MaxPower.attr, - &gadget_usb_cfg_bmAttributes.attr, + &gadget_config_desc_attr_MaxPower, + &gadget_config_desc_attr_bmAttributes, NULL, }; @@ -616,11 +597,10 @@ static struct config_item_type functions_type = { .ct_owner = THIS_MODULE, }; -CONFIGFS_ATTR_STRUCT(gadget_config_name); GS_STRINGS_RW(gadget_config_name, configuration); static struct configfs_attribute *gadget_config_name_langid_attrs[] = { - &gadget_config_name_configuration.attr, + &gadget_config_name_attr_configuration, NULL, }; @@ -719,15 +699,14 @@ static struct config_item_type config_desc_type = { .ct_owner = THIS_MODULE, }; -CONFIGFS_ATTR_STRUCT(gadget_strings); GS_STRINGS_RW(gadget_strings, manufacturer); GS_STRINGS_RW(gadget_strings, product); GS_STRINGS_RW(gadget_strings, serialnumber); static struct configfs_attribute *gadget_strings_langid_attrs[] = { - &gadget_strings_manufacturer.attr, - &gadget_strings_product.attr, - &gadget_strings_serialnumber.attr, + &gadget_strings_attr_manufacturer, + &gadget_strings_attr_product, + &gadget_strings_attr_serialnumber, NULL, }; @@ -751,27 +730,25 @@ static inline struct os_desc *to_os_desc(struct config_item *item) return container_of(to_config_group(item), struct os_desc, group); } -CONFIGFS_ATTR_STRUCT(os_desc); -CONFIGFS_ATTR_OPS(os_desc); - -static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page) +static inline struct gadget_info *os_desc_item_to_gadget_info( + struct config_item *item) { - struct gadget_info *gi; - - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); + return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent); +} - return sprintf(page, "%d", gi->use_os_desc); +static ssize_t os_desc_use_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d", + os_desc_item_to_gadget_info(item)->use_os_desc); } -static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page, +static ssize_t os_desc_use_store(struct config_item *item, const char *page, size_t len) { - struct gadget_info *gi; + struct gadget_info *gi = os_desc_item_to_gadget_info(item); int ret; bool use; - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); - mutex_lock(&gi->lock); ret = strtobool(page, &use); if (!ret) { @@ -783,29 +760,19 @@ static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page, return ret; } -static struct os_desc_attribute os_desc_use = - __CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR, - os_desc_use_show, - os_desc_use_store); - -static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page) +static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page) { - struct gadget_info *gi; - - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); - - return sprintf(page, "%d", gi->b_vendor_code); + return sprintf(page, "%d", + os_desc_item_to_gadget_info(item)->b_vendor_code); } -static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc, +static ssize_t os_desc_b_vendor_code_store(struct config_item *item, const char *page, size_t len) { - struct gadget_info *gi; + struct gadget_info *gi = os_desc_item_to_gadget_info(item); int ret; u8 b_vendor_code; - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); - mutex_lock(&gi->lock); ret = kstrtou8(page, 0, &b_vendor_code); if (!ret) { @@ -817,29 +784,20 @@ static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc, return ret; } -static struct os_desc_attribute os_desc_b_vendor_code = - __CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR, - os_desc_b_vendor_code_show, - os_desc_b_vendor_code_store); - -static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page) +static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page) { - struct gadget_info *gi; - - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); + struct gadget_info *gi = os_desc_item_to_gadget_info(item); memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN); - return OS_STRING_QW_SIGN_LEN; } -static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page, +static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page, size_t len) { - struct gadget_info *gi; + struct gadget_info *gi = os_desc_item_to_gadget_info(item); int res, l; - gi = to_gadget_info(os_desc->group.cg_item.ci_parent); l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1); if (page[l - 1] == '\n') --l; @@ -855,15 +813,14 @@ static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page, return res; } -static struct os_desc_attribute os_desc_qw_sign = - __CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR, - os_desc_qw_sign_show, - os_desc_qw_sign_store); +CONFIGFS_ATTR(os_desc_, use); +CONFIGFS_ATTR(os_desc_, b_vendor_code); +CONFIGFS_ATTR(os_desc_, qw_sign); static struct configfs_attribute *os_desc_attrs[] = { - &os_desc_use.attr, - &os_desc_b_vendor_code.attr, - &os_desc_qw_sign.attr, + &os_desc_attr_use, + &os_desc_attr_b_vendor_code, + &os_desc_attr_qw_sign, NULL, }; @@ -926,8 +883,6 @@ static int os_desc_unlink(struct config_item *os_desc_ci, static struct configfs_item_operations os_desc_ops = { .release = os_desc_attr_release, - .show_attribute = os_desc_attr_show, - .store_attribute = os_desc_attr_store, .allow_link = os_desc_link, .drop_link = os_desc_unlink, }; @@ -938,28 +893,21 @@ static struct config_item_type os_desc_type = { .ct_owner = THIS_MODULE, }; -CONFIGFS_ATTR_STRUCT(usb_os_desc); -CONFIGFS_ATTR_OPS(usb_os_desc); - - static inline struct usb_os_desc_ext_prop *to_usb_os_desc_ext_prop(struct config_item *item) { return container_of(item, struct usb_os_desc_ext_prop, item); } -CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop); -CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop); - -static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop, - char *page) +static ssize_t ext_prop_type_show(struct config_item *item, char *page) { - return sprintf(page, "%d", ext_prop->type); + return sprintf(page, "%d", to_usb_os_desc_ext_prop(item)->type); } -static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop, +static ssize_t ext_prop_type_store(struct config_item *item, const char *page, size_t len) { + struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item); struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent); u8 type; int ret; @@ -997,9 +945,9 @@ end: return ret; } -static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop, - char *page) +static ssize_t ext_prop_data_show(struct config_item *item, char *page) { + struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item); int len = ext_prop->data_len; if (ext_prop->type == USB_EXT_PROP_UNICODE || @@ -1011,9 +959,10 @@ static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop, return len; } -static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop, +static ssize_t ext_prop_data_store(struct config_item *item, const char *page, size_t len) { + struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item); struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent); char *new_data; size_t ret_len = len; @@ -1044,17 +993,12 @@ static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop, return ret_len; } -static struct usb_os_desc_ext_prop_attribute ext_prop_type = - __CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR, - ext_prop_type_show, ext_prop_type_store); - -static struct usb_os_desc_ext_prop_attribute ext_prop_data = - __CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR, - ext_prop_data_show, ext_prop_data_store); +CONFIGFS_ATTR(ext_prop_, type); +CONFIGFS_ATTR(ext_prop_, data); static struct configfs_attribute *ext_prop_attrs[] = { - &ext_prop_type.attr, - &ext_prop_data.attr, + &ext_prop_attr_type, + &ext_prop_attr_data, NULL, }; @@ -1067,8 +1011,6 @@ static void usb_os_desc_ext_prop_release(struct config_item *item) static struct configfs_item_operations ext_prop_ops = { .release = usb_os_desc_ext_prop_release, - .show_attribute = usb_os_desc_ext_prop_attr_show, - .store_attribute = usb_os_desc_ext_prop_attr_store, }; static struct config_item *ext_prop_make( @@ -1137,21 +1079,17 @@ static struct configfs_group_operations interf_grp_ops = { .drop_item = &ext_prop_drop, }; -static struct configfs_item_operations interf_item_ops = { - .show_attribute = usb_os_desc_attr_show, - .store_attribute = usb_os_desc_attr_store, -}; - -static ssize_t interf_grp_compatible_id_show(struct usb_os_desc *desc, +static ssize_t interf_grp_compatible_id_show(struct config_item *item, char *page) { - memcpy(page, desc->ext_compat_id, 8); + memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8); return 8; } -static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc, +static ssize_t interf_grp_compatible_id_store(struct config_item *item, const char *page, size_t len) { + struct usb_os_desc *desc = to_usb_os_desc(item); int l; l = min_t(int, 8, len); @@ -1167,21 +1105,17 @@ static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc, return len; } -static struct usb_os_desc_attribute interf_grp_attr_compatible_id = - __CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR, - interf_grp_compatible_id_show, - interf_grp_compatible_id_store); - -static ssize_t interf_grp_sub_compatible_id_show(struct usb_os_desc *desc, +static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item, char *page) { - memcpy(page, desc->ext_compat_id + 8, 8); + memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8); return 8; } -static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc, +static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item, const char *page, size_t len) { + struct usb_os_desc *desc = to_usb_os_desc(item); int l; l = min_t(int, 8, len); @@ -1197,14 +1131,12 @@ static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc, return len; } -static struct usb_os_desc_attribute interf_grp_attr_sub_compatible_id = - __CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR, - interf_grp_sub_compatible_id_show, - interf_grp_sub_compatible_id_store); +CONFIGFS_ATTR(interf_grp_, compatible_id); +CONFIGFS_ATTR(interf_grp_, sub_compatible_id); static struct configfs_attribute *interf_grp_attrs[] = { - &interf_grp_attr_compatible_id.attr, - &interf_grp_attr_sub_compatible_id.attr, + &interf_grp_attr_compatible_id, + &interf_grp_attr_sub_compatible_id, NULL }; @@ -1242,7 +1174,6 @@ int usb_os_desc_prepare_interf_dir(struct config_group *parent, f_default_groups[0] = os_desc_group; os_desc_group->default_groups = interface_groups; - interface_type->ct_item_ops = &interf_item_ops; interface_type->ct_group_ops = &interf_grp_ops; interface_type->ct_attrs = interf_grp_attrs; interface_type->ct_owner = owner; diff --git a/include/linux/usb/gadget_configfs.h b/include/linux/usb/gadget_configfs.h index d74c0ae989d5..c36e95730de1 100644 --- a/include/linux/usb/gadget_configfs.h +++ b/include/linux/usb/gadget_configfs.h @@ -7,9 +7,10 @@ int check_user_usb_string(const char *name, struct usb_gadget_strings *stringtab_dev); #define GS_STRINGS_W(__struct, __name) \ - static ssize_t __struct##_##__name##_store(struct __struct *gs, \ +static ssize_t __struct##_##__name##_store(struct config_item *item, \ const char *page, size_t len) \ { \ + struct __struct *gs = to_##__struct(item); \ int ret; \ \ ret = usb_string_copy(page, &gs->__name); \ @@ -19,30 +20,20 @@ int check_user_usb_string(const char *name, } #define GS_STRINGS_R(__struct, __name) \ - static ssize_t __struct##_##__name##_show(struct __struct *gs, \ - char *page) \ +static ssize_t __struct##_##__name##_show(struct config_item *item, char *page) \ { \ + struct __struct *gs = to_##__struct(item); \ return sprintf(page, "%s\n", gs->__name ?: ""); \ } -#define GS_STRING_ITEM_ATTR(struct_name, name) \ - static struct struct_name##_attribute struct_name##_##name = \ - __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, \ - struct_name##_##name##_show, \ - struct_name##_##name##_store) - #define GS_STRINGS_RW(struct_name, _name) \ GS_STRINGS_R(struct_name, _name) \ GS_STRINGS_W(struct_name, _name) \ - GS_STRING_ITEM_ATTR(struct_name, _name) + CONFIGFS_ATTR(struct_name##_, _name) #define USB_CONFIG_STRING_RW_OPS(struct_in) \ - CONFIGFS_ATTR_OPS(struct_in); \ - \ static struct configfs_item_operations struct_in##_langid_item_ops = { \ .release = struct_in##_attr_release, \ - .show_attribute = struct_in##_attr_show, \ - .store_attribute = struct_in##_attr_store, \ }; \ \ static struct config_item_type struct_in##_langid_type = { \ -- cgit v1.2.3 From 517982229f78b2aebf00a8a337e84e8eeea70b8e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Oct 2015 15:32:59 +0200 Subject: configfs: remove old API Remove the old show_attribute and store_attribute methods and update the documentation. Also replace the two C samples with a single new one in the proper samples directory where people expect to find it. Signed-off-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger --- Documentation/filesystems/Makefile | 2 - Documentation/filesystems/configfs/Makefile | 3 - Documentation/filesystems/configfs/configfs.txt | 38 +- .../configfs/configfs_example_explicit.c | 483 --------------------- .../filesystems/configfs/configfs_example_macros.c | 446 ------------------- fs/configfs/file.c | 15 +- include/linux/configfs.h | 82 ---- samples/Kconfig | 6 + samples/Makefile | 3 +- samples/configfs/Makefile | 2 + samples/configfs/configfs_sample.c | 404 +++++++++++++++++ 11 files changed, 428 insertions(+), 1056 deletions(-) delete mode 100644 Documentation/filesystems/configfs/Makefile delete mode 100644 Documentation/filesystems/configfs/configfs_example_explicit.c delete mode 100644 Documentation/filesystems/configfs/configfs_example_macros.c create mode 100644 samples/configfs/Makefile create mode 100644 samples/configfs/configfs_sample.c (limited to 'include/linux') diff --git a/Documentation/filesystems/Makefile b/Documentation/filesystems/Makefile index 13483d192ebb..883010ce5e35 100644 --- a/Documentation/filesystems/Makefile +++ b/Documentation/filesystems/Makefile @@ -1,5 +1,3 @@ -subdir-y := configfs - # List of programs to build hostprogs-y := dnotify_test diff --git a/Documentation/filesystems/configfs/Makefile b/Documentation/filesystems/configfs/Makefile deleted file mode 100644 index be7ec5e67dbc..000000000000 --- a/Documentation/filesystems/configfs/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -ifneq ($(CONFIG_CONFIGFS_FS),) -obj-m += configfs_example_explicit.o configfs_example_macros.o -endif diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt index b40fec9d3f53..af68efdbbfad 100644 --- a/Documentation/filesystems/configfs/configfs.txt +++ b/Documentation/filesystems/configfs/configfs.txt @@ -160,12 +160,6 @@ among other things. For that, it needs a type. struct configfs_item_operations { void (*release)(struct config_item *); - ssize_t (*show_attribute)(struct config_item *, - struct configfs_attribute *, - char *); - ssize_t (*store_attribute)(struct config_item *, - struct configfs_attribute *, - const char *, size_t); int (*allow_link)(struct config_item *src, struct config_item *target); int (*drop_link)(struct config_item *src, @@ -183,9 +177,7 @@ The most basic function of a config_item_type is to define what operations can be performed on a config_item. All items that have been allocated dynamically will need to provide the ct_item_ops->release() method. This method is called when the config_item's reference count -reaches zero. Items that wish to display an attribute need to provide -the ct_item_ops->show_attribute() method. Similarly, storing a new -attribute value uses the store_attribute() method. +reaches zero. [struct configfs_attribute] @@ -193,6 +185,8 @@ attribute value uses the store_attribute() method. char *ca_name; struct module *ca_owner; umode_t ca_mode; + ssize_t (*show)(struct config_item *, char *); + ssize_t (*store)(struct config_item *, const char *, size_t); }; When a config_item wants an attribute to appear as a file in the item's @@ -202,10 +196,10 @@ config_item_type->ct_attrs. When the item appears in configfs, the attribute file will appear with the configfs_attribute->ca_name filename. configfs_attribute->ca_mode specifies the file permissions. -If an attribute is readable and the config_item provides a -ct_item_ops->show_attribute() method, that method will be called -whenever userspace asks for a read(2) on the attribute. The converse -will happen for write(2). +If an attribute is readable and provides a ->show method, that method will +be called whenever userspace asks for a read(2) on the attribute. If an +attribute is writable and provides a ->store method, that method will be +be called whenever userspace asks for a write(2) on the attribute. [struct config_group] @@ -311,20 +305,10 @@ the subsystem must be ready for it. [An Example] The best example of these basic concepts is the simple_children -subsystem/group and the simple_child item in configfs_example_explicit.c -and configfs_example_macros.c. It shows a trivial object displaying and -storing an attribute, and a simple group creating and destroying these -children. - -The only difference between configfs_example_explicit.c and -configfs_example_macros.c is how the attributes of the childless item -are defined. The childless item has extended attributes, each with -their own show()/store() operation. This follows a convention commonly -used in sysfs. configfs_example_explicit.c creates these attributes -by explicitly defining the structures involved. Conversely -configfs_example_macros.c uses some convenience macros from configfs.h -to define the attributes. These macros are similar to their sysfs -counterparts. +subsystem/group and the simple_child item in +samples/configfs/configfs_sample.c. It shows a trivial object displaying +and storing an attribute, and a simple group creating and destroying +these children. [Hierarchy Navigation and the Subsystem Mutex] diff --git a/Documentation/filesystems/configfs/configfs_example_explicit.c b/Documentation/filesystems/configfs/configfs_example_explicit.c deleted file mode 100644 index 1420233dfa55..000000000000 --- a/Documentation/filesystems/configfs/configfs_example_explicit.c +++ /dev/null @@ -1,483 +0,0 @@ -/* - * vim: noexpandtab ts=8 sts=0 sw=8: - * - * configfs_example_explicit.c - This file is a demonstration module - * containing a number of configfs subsystems. It explicitly defines - * each structure without using the helper macros defined in - * configfs.h. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this program; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 021110-1307, USA. - * - * Based on sysfs: - * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel - * - * configfs Copyright (C) 2005 Oracle. All rights reserved. - */ - -#include -#include -#include - -#include - - - -/* - * 01-childless - * - * This first example is a childless subsystem. It cannot create - * any config_items. It just has attributes. - * - * Note that we are enclosing the configfs_subsystem inside a container. - * This is not necessary if a subsystem has no attributes directly - * on the subsystem. See the next example, 02-simple-children, for - * such a subsystem. - */ - -struct childless { - struct configfs_subsystem subsys; - int showme; - int storeme; -}; - -struct childless_attribute { - struct configfs_attribute attr; - ssize_t (*show)(struct childless *, char *); - ssize_t (*store)(struct childless *, const char *, size_t); -}; - -static inline struct childless *to_childless(struct config_item *item) -{ - return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL; -} - -static ssize_t childless_showme_read(struct childless *childless, - char *page) -{ - ssize_t pos; - - pos = sprintf(page, "%d\n", childless->showme); - childless->showme++; - - return pos; -} - -static ssize_t childless_storeme_read(struct childless *childless, - char *page) -{ - return sprintf(page, "%d\n", childless->storeme); -} - -static ssize_t childless_storeme_write(struct childless *childless, - const char *page, - size_t count) -{ - unsigned long tmp; - char *p = (char *) page; - - tmp = simple_strtoul(p, &p, 10); - if ((*p != '\0') && (*p != '\n')) - return -EINVAL; - - if (tmp > INT_MAX) - return -ERANGE; - - childless->storeme = tmp; - - return count; -} - -static ssize_t childless_description_read(struct childless *childless, - char *page) -{ - return sprintf(page, -"[01-childless]\n" -"\n" -"The childless subsystem is the simplest possible subsystem in\n" -"configfs. It does not support the creation of child config_items.\n" -"It only has a few attributes. In fact, it isn't much different\n" -"than a directory in /proc.\n"); -} - -static struct childless_attribute childless_attr_showme = { - .attr = { .ca_owner = THIS_MODULE, .ca_name = "showme", .ca_mode = S_IRUGO }, - .show = childless_showme_read, -}; -static struct childless_attribute childless_attr_storeme = { - .attr = { .ca_owner = THIS_MODULE, .ca_name = "storeme", .ca_mode = S_IRUGO | S_IWUSR }, - .show = childless_storeme_read, - .store = childless_storeme_write, -}; -static struct childless_attribute childless_attr_description = { - .attr = { .ca_owner = THIS_MODULE, .ca_name = "description", .ca_mode = S_IRUGO }, - .show = childless_description_read, -}; - -static struct configfs_attribute *childless_attrs[] = { - &childless_attr_showme.attr, - &childless_attr_storeme.attr, - &childless_attr_description.attr, - NULL, -}; - -static ssize_t childless_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - struct childless *childless = to_childless(item); - struct childless_attribute *childless_attr = - container_of(attr, struct childless_attribute, attr); - ssize_t ret = 0; - - if (childless_attr->show) - ret = childless_attr->show(childless, page); - return ret; -} - -static ssize_t childless_attr_store(struct config_item *item, - struct configfs_attribute *attr, - const char *page, size_t count) -{ - struct childless *childless = to_childless(item); - struct childless_attribute *childless_attr = - container_of(attr, struct childless_attribute, attr); - ssize_t ret = -EINVAL; - - if (childless_attr->store) - ret = childless_attr->store(childless, page, count); - return ret; -} - -static struct configfs_item_operations childless_item_ops = { - .show_attribute = childless_attr_show, - .store_attribute = childless_attr_store, -}; - -static struct config_item_type childless_type = { - .ct_item_ops = &childless_item_ops, - .ct_attrs = childless_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct childless childless_subsys = { - .subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "01-childless", - .ci_type = &childless_type, - }, - }, - }, -}; - - -/* ----------------------------------------------------------------- */ - -/* - * 02-simple-children - * - * This example merely has a simple one-attribute child. Note that - * there is no extra attribute structure, as the child's attribute is - * known from the get-go. Also, there is no container for the - * subsystem, as it has no attributes of its own. - */ - -struct simple_child { - struct config_item item; - int storeme; -}; - -static inline struct simple_child *to_simple_child(struct config_item *item) -{ - return item ? container_of(item, struct simple_child, item) : NULL; -} - -static struct configfs_attribute simple_child_attr_storeme = { - .ca_owner = THIS_MODULE, - .ca_name = "storeme", - .ca_mode = S_IRUGO | S_IWUSR, -}; - -static struct configfs_attribute *simple_child_attrs[] = { - &simple_child_attr_storeme, - NULL, -}; - -static ssize_t simple_child_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - ssize_t count; - struct simple_child *simple_child = to_simple_child(item); - - count = sprintf(page, "%d\n", simple_child->storeme); - - return count; -} - -static ssize_t simple_child_attr_store(struct config_item *item, - struct configfs_attribute *attr, - const char *page, size_t count) -{ - struct simple_child *simple_child = to_simple_child(item); - unsigned long tmp; - char *p = (char *) page; - - tmp = simple_strtoul(p, &p, 10); - if (!p || (*p && (*p != '\n'))) - return -EINVAL; - - if (tmp > INT_MAX) - return -ERANGE; - - simple_child->storeme = tmp; - - return count; -} - -static void simple_child_release(struct config_item *item) -{ - kfree(to_simple_child(item)); -} - -static struct configfs_item_operations simple_child_item_ops = { - .release = simple_child_release, - .show_attribute = simple_child_attr_show, - .store_attribute = simple_child_attr_store, -}; - -static struct config_item_type simple_child_type = { - .ct_item_ops = &simple_child_item_ops, - .ct_attrs = simple_child_attrs, - .ct_owner = THIS_MODULE, -}; - - -struct simple_children { - struct config_group group; -}; - -static inline struct simple_children *to_simple_children(struct config_item *item) -{ - return item ? container_of(to_config_group(item), struct simple_children, group) : NULL; -} - -static struct config_item *simple_children_make_item(struct config_group *group, const char *name) -{ - struct simple_child *simple_child; - - simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); - if (!simple_child) - return ERR_PTR(-ENOMEM); - - config_item_init_type_name(&simple_child->item, name, - &simple_child_type); - - simple_child->storeme = 0; - - return &simple_child->item; -} - -static struct configfs_attribute simple_children_attr_description = { - .ca_owner = THIS_MODULE, - .ca_name = "description", - .ca_mode = S_IRUGO, -}; - -static struct configfs_attribute *simple_children_attrs[] = { - &simple_children_attr_description, - NULL, -}; - -static ssize_t simple_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - return sprintf(page, -"[02-simple-children]\n" -"\n" -"This subsystem allows the creation of child config_items. These\n" -"items have only one attribute that is readable and writeable.\n"); -} - -static void simple_children_release(struct config_item *item) -{ - kfree(to_simple_children(item)); -} - -static struct configfs_item_operations simple_children_item_ops = { - .release = simple_children_release, - .show_attribute = simple_children_attr_show, -}; - -/* - * Note that, since no extra work is required on ->drop_item(), - * no ->drop_item() is provided. - */ -static struct configfs_group_operations simple_children_group_ops = { - .make_item = simple_children_make_item, -}; - -static struct config_item_type simple_children_type = { - .ct_item_ops = &simple_children_item_ops, - .ct_group_ops = &simple_children_group_ops, - .ct_attrs = simple_children_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct configfs_subsystem simple_children_subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "02-simple-children", - .ci_type = &simple_children_type, - }, - }, -}; - - -/* ----------------------------------------------------------------- */ - -/* - * 03-group-children - * - * This example reuses the simple_children group from above. However, - * the simple_children group is not the subsystem itself, it is a - * child of the subsystem. Creation of a group in the subsystem creates - * a new simple_children group. That group can then have simple_child - * children of its own. - */ - -static struct config_group *group_children_make_group(struct config_group *group, const char *name) -{ - struct simple_children *simple_children; - - simple_children = kzalloc(sizeof(struct simple_children), - GFP_KERNEL); - if (!simple_children) - return ERR_PTR(-ENOMEM); - - config_group_init_type_name(&simple_children->group, name, - &simple_children_type); - - return &simple_children->group; -} - -static struct configfs_attribute group_children_attr_description = { - .ca_owner = THIS_MODULE, - .ca_name = "description", - .ca_mode = S_IRUGO, -}; - -static struct configfs_attribute *group_children_attrs[] = { - &group_children_attr_description, - NULL, -}; - -static ssize_t group_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - return sprintf(page, -"[03-group-children]\n" -"\n" -"This subsystem allows the creation of child config_groups. These\n" -"groups are like the subsystem simple-children.\n"); -} - -static struct configfs_item_operations group_children_item_ops = { - .show_attribute = group_children_attr_show, -}; - -/* - * Note that, since no extra work is required on ->drop_item(), - * no ->drop_item() is provided. - */ -static struct configfs_group_operations group_children_group_ops = { - .make_group = group_children_make_group, -}; - -static struct config_item_type group_children_type = { - .ct_item_ops = &group_children_item_ops, - .ct_group_ops = &group_children_group_ops, - .ct_attrs = group_children_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct configfs_subsystem group_children_subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "03-group-children", - .ci_type = &group_children_type, - }, - }, -}; - -/* ----------------------------------------------------------------- */ - -/* - * We're now done with our subsystem definitions. - * For convenience in this module, here's a list of them all. It - * allows the init function to easily register them. Most modules - * will only have one subsystem, and will only call register_subsystem - * on it directly. - */ -static struct configfs_subsystem *example_subsys[] = { - &childless_subsys.subsys, - &simple_children_subsys, - &group_children_subsys, - NULL, -}; - -static int __init configfs_example_init(void) -{ - int ret; - int i; - struct configfs_subsystem *subsys; - - for (i = 0; example_subsys[i]; i++) { - subsys = example_subsys[i]; - - config_group_init(&subsys->su_group); - mutex_init(&subsys->su_mutex); - ret = configfs_register_subsystem(subsys); - if (ret) { - printk(KERN_ERR "Error %d while registering subsystem %s\n", - ret, - subsys->su_group.cg_item.ci_namebuf); - goto out_unregister; - } - } - - return 0; - -out_unregister: - for (i--; i >= 0; i--) - configfs_unregister_subsystem(example_subsys[i]); - - return ret; -} - -static void __exit configfs_example_exit(void) -{ - int i; - - for (i = 0; example_subsys[i]; i++) - configfs_unregister_subsystem(example_subsys[i]); -} - -module_init(configfs_example_init); -module_exit(configfs_example_exit); -MODULE_LICENSE("GPL"); diff --git a/Documentation/filesystems/configfs/configfs_example_macros.c b/Documentation/filesystems/configfs/configfs_example_macros.c deleted file mode 100644 index 327dfbc640a9..000000000000 --- a/Documentation/filesystems/configfs/configfs_example_macros.c +++ /dev/null @@ -1,446 +0,0 @@ -/* - * vim: noexpandtab ts=8 sts=0 sw=8: - * - * configfs_example_macros.c - This file is a demonstration module - * containing a number of configfs subsystems. It uses the helper - * macros defined by configfs.h - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this program; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 021110-1307, USA. - * - * Based on sysfs: - * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel - * - * configfs Copyright (C) 2005 Oracle. All rights reserved. - */ - -#include -#include -#include - -#include - - - -/* - * 01-childless - * - * This first example is a childless subsystem. It cannot create - * any config_items. It just has attributes. - * - * Note that we are enclosing the configfs_subsystem inside a container. - * This is not necessary if a subsystem has no attributes directly - * on the subsystem. See the next example, 02-simple-children, for - * such a subsystem. - */ - -struct childless { - struct configfs_subsystem subsys; - int showme; - int storeme; -}; - -static inline struct childless *to_childless(struct config_item *item) -{ - return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL; -} - -CONFIGFS_ATTR_STRUCT(childless); -#define CHILDLESS_ATTR(_name, _mode, _show, _store) \ -struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store) -#define CHILDLESS_ATTR_RO(_name, _show) \ -struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show); - -static ssize_t childless_showme_read(struct childless *childless, - char *page) -{ - ssize_t pos; - - pos = sprintf(page, "%d\n", childless->showme); - childless->showme++; - - return pos; -} - -static ssize_t childless_storeme_read(struct childless *childless, - char *page) -{ - return sprintf(page, "%d\n", childless->storeme); -} - -static ssize_t childless_storeme_write(struct childless *childless, - const char *page, - size_t count) -{ - unsigned long tmp; - char *p = (char *) page; - - tmp = simple_strtoul(p, &p, 10); - if (!p || (*p && (*p != '\n'))) - return -EINVAL; - - if (tmp > INT_MAX) - return -ERANGE; - - childless->storeme = tmp; - - return count; -} - -static ssize_t childless_description_read(struct childless *childless, - char *page) -{ - return sprintf(page, -"[01-childless]\n" -"\n" -"The childless subsystem is the simplest possible subsystem in\n" -"configfs. It does not support the creation of child config_items.\n" -"It only has a few attributes. In fact, it isn't much different\n" -"than a directory in /proc.\n"); -} - -CHILDLESS_ATTR_RO(showme, childless_showme_read); -CHILDLESS_ATTR(storeme, S_IRUGO | S_IWUSR, childless_storeme_read, - childless_storeme_write); -CHILDLESS_ATTR_RO(description, childless_description_read); - -static struct configfs_attribute *childless_attrs[] = { - &childless_attr_showme.attr, - &childless_attr_storeme.attr, - &childless_attr_description.attr, - NULL, -}; - -CONFIGFS_ATTR_OPS(childless); -static struct configfs_item_operations childless_item_ops = { - .show_attribute = childless_attr_show, - .store_attribute = childless_attr_store, -}; - -static struct config_item_type childless_type = { - .ct_item_ops = &childless_item_ops, - .ct_attrs = childless_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct childless childless_subsys = { - .subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "01-childless", - .ci_type = &childless_type, - }, - }, - }, -}; - - -/* ----------------------------------------------------------------- */ - -/* - * 02-simple-children - * - * This example merely has a simple one-attribute child. Note that - * there is no extra attribute structure, as the child's attribute is - * known from the get-go. Also, there is no container for the - * subsystem, as it has no attributes of its own. - */ - -struct simple_child { - struct config_item item; - int storeme; -}; - -static inline struct simple_child *to_simple_child(struct config_item *item) -{ - return item ? container_of(item, struct simple_child, item) : NULL; -} - -static struct configfs_attribute simple_child_attr_storeme = { - .ca_owner = THIS_MODULE, - .ca_name = "storeme", - .ca_mode = S_IRUGO | S_IWUSR, -}; - -static struct configfs_attribute *simple_child_attrs[] = { - &simple_child_attr_storeme, - NULL, -}; - -static ssize_t simple_child_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - ssize_t count; - struct simple_child *simple_child = to_simple_child(item); - - count = sprintf(page, "%d\n", simple_child->storeme); - - return count; -} - -static ssize_t simple_child_attr_store(struct config_item *item, - struct configfs_attribute *attr, - const char *page, size_t count) -{ - struct simple_child *simple_child = to_simple_child(item); - unsigned long tmp; - char *p = (char *) page; - - tmp = simple_strtoul(p, &p, 10); - if (!p || (*p && (*p != '\n'))) - return -EINVAL; - - if (tmp > INT_MAX) - return -ERANGE; - - simple_child->storeme = tmp; - - return count; -} - -static void simple_child_release(struct config_item *item) -{ - kfree(to_simple_child(item)); -} - -static struct configfs_item_operations simple_child_item_ops = { - .release = simple_child_release, - .show_attribute = simple_child_attr_show, - .store_attribute = simple_child_attr_store, -}; - -static struct config_item_type simple_child_type = { - .ct_item_ops = &simple_child_item_ops, - .ct_attrs = simple_child_attrs, - .ct_owner = THIS_MODULE, -}; - - -struct simple_children { - struct config_group group; -}; - -static inline struct simple_children *to_simple_children(struct config_item *item) -{ - return item ? container_of(to_config_group(item), struct simple_children, group) : NULL; -} - -static struct config_item *simple_children_make_item(struct config_group *group, const char *name) -{ - struct simple_child *simple_child; - - simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); - if (!simple_child) - return ERR_PTR(-ENOMEM); - - config_item_init_type_name(&simple_child->item, name, - &simple_child_type); - - simple_child->storeme = 0; - - return &simple_child->item; -} - -static struct configfs_attribute simple_children_attr_description = { - .ca_owner = THIS_MODULE, - .ca_name = "description", - .ca_mode = S_IRUGO, -}; - -static struct configfs_attribute *simple_children_attrs[] = { - &simple_children_attr_description, - NULL, -}; - -static ssize_t simple_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - return sprintf(page, -"[02-simple-children]\n" -"\n" -"This subsystem allows the creation of child config_items. These\n" -"items have only one attribute that is readable and writeable.\n"); -} - -static void simple_children_release(struct config_item *item) -{ - kfree(to_simple_children(item)); -} - -static struct configfs_item_operations simple_children_item_ops = { - .release = simple_children_release, - .show_attribute = simple_children_attr_show, -}; - -/* - * Note that, since no extra work is required on ->drop_item(), - * no ->drop_item() is provided. - */ -static struct configfs_group_operations simple_children_group_ops = { - .make_item = simple_children_make_item, -}; - -static struct config_item_type simple_children_type = { - .ct_item_ops = &simple_children_item_ops, - .ct_group_ops = &simple_children_group_ops, - .ct_attrs = simple_children_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct configfs_subsystem simple_children_subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "02-simple-children", - .ci_type = &simple_children_type, - }, - }, -}; - - -/* ----------------------------------------------------------------- */ - -/* - * 03-group-children - * - * This example reuses the simple_children group from above. However, - * the simple_children group is not the subsystem itself, it is a - * child of the subsystem. Creation of a group in the subsystem creates - * a new simple_children group. That group can then have simple_child - * children of its own. - */ - -static struct config_group *group_children_make_group(struct config_group *group, const char *name) -{ - struct simple_children *simple_children; - - simple_children = kzalloc(sizeof(struct simple_children), - GFP_KERNEL); - if (!simple_children) - return ERR_PTR(-ENOMEM); - - config_group_init_type_name(&simple_children->group, name, - &simple_children_type); - - return &simple_children->group; -} - -static struct configfs_attribute group_children_attr_description = { - .ca_owner = THIS_MODULE, - .ca_name = "description", - .ca_mode = S_IRUGO, -}; - -static struct configfs_attribute *group_children_attrs[] = { - &group_children_attr_description, - NULL, -}; - -static ssize_t group_children_attr_show(struct config_item *item, - struct configfs_attribute *attr, - char *page) -{ - return sprintf(page, -"[03-group-children]\n" -"\n" -"This subsystem allows the creation of child config_groups. These\n" -"groups are like the subsystem simple-children.\n"); -} - -static struct configfs_item_operations group_children_item_ops = { - .show_attribute = group_children_attr_show, -}; - -/* - * Note that, since no extra work is required on ->drop_item(), - * no ->drop_item() is provided. - */ -static struct configfs_group_operations group_children_group_ops = { - .make_group = group_children_make_group, -}; - -static struct config_item_type group_children_type = { - .ct_item_ops = &group_children_item_ops, - .ct_group_ops = &group_children_group_ops, - .ct_attrs = group_children_attrs, - .ct_owner = THIS_MODULE, -}; - -static struct configfs_subsystem group_children_subsys = { - .su_group = { - .cg_item = { - .ci_namebuf = "03-group-children", - .ci_type = &group_children_type, - }, - }, -}; - -/* ----------------------------------------------------------------- */ - -/* - * We're now done with our subsystem definitions. - * For convenience in this module, here's a list of them all. It - * allows the init function to easily register them. Most modules - * will only have one subsystem, and will only call register_subsystem - * on it directly. - */ -static struct configfs_subsystem *example_subsys[] = { - &childless_subsys.subsys, - &simple_children_subsys, - &group_children_subsys, - NULL, -}; - -static int __init configfs_example_init(void) -{ - int ret; - int i; - struct configfs_subsystem *subsys; - - for (i = 0; example_subsys[i]; i++) { - subsys = example_subsys[i]; - - config_group_init(&subsys->su_group); - mutex_init(&subsys->su_mutex); - ret = configfs_register_subsystem(subsys); - if (ret) { - printk(KERN_ERR "Error %d while registering subsystem %s\n", - ret, - subsys->su_group.cg_item.ci_namebuf); - goto out_unregister; - } - } - - return 0; - -out_unregister: - for (i--; i >= 0; i--) - configfs_unregister_subsystem(example_subsys[i]); - - return ret; -} - -static void __exit configfs_example_exit(void) -{ - int i; - - for (i = 0; example_subsys[i]; i++) - configfs_unregister_subsystem(example_subsys[i]); -} - -module_init(configfs_example_init); -module_exit(configfs_example_exit); -MODULE_LICENSE("GPL"); diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 106ca589e90a..d39099ea7df7 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -65,7 +65,6 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf { struct configfs_attribute * attr = to_attr(dentry); struct config_item * item = to_item(dentry->d_parent); - struct configfs_item_operations * ops = buffer->ops; int ret = 0; ssize_t count; @@ -74,10 +73,7 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf if (!buffer->page) return -ENOMEM; - if (ops->show_attribute) - count = ops->show_attribute(item, attr, buffer->page); - else - count = attr->show(item, buffer->page); + count = attr->show(item, buffer->page); buffer->needs_read_fill = 0; BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE); @@ -175,10 +171,7 @@ flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size { struct configfs_attribute * attr = to_attr(dentry); struct config_item * item = to_item(dentry->d_parent); - struct configfs_item_operations * ops = buffer->ops; - if (ops->store_attribute) - return ops->store_attribute(item, attr, buffer->page, count); return attr->store(item, buffer->page, count); } @@ -243,8 +236,7 @@ static int check_perm(struct inode * inode, struct file * file) * and we must have a store method. */ if (file->f_mode & FMODE_WRITE) { - if (!(inode->i_mode & S_IWUGO) || - (!ops->store_attribute && !attr->store)) + if (!(inode->i_mode & S_IWUGO) || !attr->store) goto Eaccess; } @@ -254,8 +246,7 @@ static int check_perm(struct inode * inode, struct file * file) * must be a show method for it. */ if (file->f_mode & FMODE_READ) { - if (!(inode->i_mode & S_IRUGO) || - (!ops->show_attribute && !attr->show)) + if (!(inode->i_mode & S_IRUGO) || !attr->show) goto Eaccess; } diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 85e9956a86de..a8a335b7fce0 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -154,86 +154,6 @@ static struct configfs_attribute _pfx##attr_##_name = { \ .store = _pfx##_name##_store, \ } -/* - * Users often need to create attribute structures for their configurable - * attributes, containing a configfs_attribute member and function pointers - * for the show() and store() operations on that attribute. If they don't - * need anything else on the extended attribute structure, they can use - * this macro to define it The argument _item is the name of the - * config_item structure. - */ -#define CONFIGFS_ATTR_STRUCT(_item) \ -struct _item##_attribute { \ - struct configfs_attribute attr; \ - ssize_t (*show)(struct _item *, char *); \ - ssize_t (*store)(struct _item *, const char *, size_t); \ -} - -/* - * With the extended attribute structure, users can use this macro - * (similar to sysfs' __ATTR) to make defining attributes easier. - * An example: - * #define MYITEM_ATTR(_name, _mode, _show, _store) \ - * struct myitem_attribute childless_attr_##_name = \ - * __CONFIGFS_ATTR(_name, _mode, _show, _store) - */ -#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \ -{ \ - .attr = { \ - .ca_name = __stringify(_name), \ - .ca_mode = _mode, \ - .ca_owner = THIS_MODULE, \ - }, \ - .show = _show, \ - .store = _store, \ -} -/* Here is a readonly version, only requiring a show() operation */ -#define __CONFIGFS_ATTR_RO(_name, _show) \ -{ \ - .attr = { \ - .ca_name = __stringify(_name), \ - .ca_mode = 0444, \ - .ca_owner = THIS_MODULE, \ - }, \ - .show = _show, \ -} - -/* - * With these extended attributes, the simple show_attribute() and - * store_attribute() operations need to call the show() and store() of the - * attributes. This is a common pattern, so we provide a macro to define - * them. The argument _item is the name of the config_item structure. - * This macro expects the attributes to be named "struct _attribute" - * and the function to_() to exist; - */ -#define CONFIGFS_ATTR_OPS(_item) \ -static ssize_t _item##_attr_show(struct config_item *item, \ - struct configfs_attribute *attr, \ - char *page) \ -{ \ - struct _item *_item = to_##_item(item); \ - struct _item##_attribute *_item##_attr = \ - container_of(attr, struct _item##_attribute, attr); \ - ssize_t ret = 0; \ - \ - if (_item##_attr->show) \ - ret = _item##_attr->show(_item, page); \ - return ret; \ -} \ -static ssize_t _item##_attr_store(struct config_item *item, \ - struct configfs_attribute *attr, \ - const char *page, size_t count) \ -{ \ - struct _item *_item = to_##_item(item); \ - struct _item##_attribute *_item##_attr = \ - container_of(attr, struct _item##_attribute, attr); \ - ssize_t ret = -EINVAL; \ - \ - if (_item##_attr->store) \ - ret = _item##_attr->store(_item, page, count); \ - return ret; \ -} - /* * If allow_link() exists, the item can symlink(2) out to other * items. If the item is a group, it may support mkdir(2). @@ -250,8 +170,6 @@ static ssize_t _item##_attr_store(struct config_item *item, \ */ struct configfs_item_operations { void (*release)(struct config_item *); - ssize_t (*show_attribute)(struct config_item *, struct configfs_attribute *,char *); - ssize_t (*store_attribute)(struct config_item *,struct configfs_attribute *,const char *, size_t); int (*allow_link)(struct config_item *src, struct config_item *target); int (*drop_link)(struct config_item *src, struct config_item *target); }; diff --git a/samples/Kconfig b/samples/Kconfig index 224ebb46bed5..d54f28c6dc5e 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -70,4 +70,10 @@ config SAMPLE_LIVEPATCH Builds a sample live patch that replaces the procfs handler for /proc/cmdline to print "this has been live patched". +config SAMPLE_CONFIGFS + tristate "Build configfs patching sample -- loadable modules only" + depends on CONFIGFS_FS && m + help + Builds a sample configfs interface. + endif # SAMPLES diff --git a/samples/Makefile b/samples/Makefile index f00257bcc5a7..48001d7e23f0 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -1,4 +1,5 @@ # Makefile for Linux samples code obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \ - hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ + hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \ + configfs/ diff --git a/samples/configfs/Makefile b/samples/configfs/Makefile new file mode 100644 index 000000000000..a9afd99630fc --- /dev/null +++ b/samples/configfs/Makefile @@ -0,0 +1,2 @@ + +obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs_sample.o diff --git a/samples/configfs/configfs_sample.c b/samples/configfs/configfs_sample.c new file mode 100644 index 000000000000..1ea33119e532 --- /dev/null +++ b/samples/configfs/configfs_sample.c @@ -0,0 +1,404 @@ +/* + * vim: noexpandtab ts=8 sts=0 sw=8: + * + * configfs_example_macros.c - This file is a demonstration module + * containing a number of configfs subsystems. It uses the helper + * macros defined by configfs.h + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include +#include +#include + +#include + + + +/* + * 01-childless + * + * This first example is a childless subsystem. It cannot create + * any config_items. It just has attributes. + * + * Note that we are enclosing the configfs_subsystem inside a container. + * This is not necessary if a subsystem has no attributes directly + * on the subsystem. See the next example, 02-simple-children, for + * such a subsystem. + */ + +struct childless { + struct configfs_subsystem subsys; + int showme; + int storeme; +}; + +static inline struct childless *to_childless(struct config_item *item) +{ + return item ? container_of(to_configfs_subsystem(to_config_group(item)), + struct childless, subsys) : NULL; +} + +static ssize_t childless_showme_show(struct config_item *item, char *page) +{ + struct childless *childless = to_childless(item); + ssize_t pos; + + pos = sprintf(page, "%d\n", childless->showme); + childless->showme++; + + return pos; +} + +static ssize_t childless_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_childless(item)->storeme); +} + +static ssize_t childless_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct childless *childless = to_childless(item); + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + childless->storeme = tmp; + + return count; +} + +static ssize_t childless_description_show(struct config_item *item, char *page) +{ + return sprintf(page, +"[01-childless]\n" +"\n" +"The childless subsystem is the simplest possible subsystem in\n" +"configfs. It does not support the creation of child config_items.\n" +"It only has a few attributes. In fact, it isn't much different\n" +"than a directory in /proc.\n"); +} + +CONFIGFS_ATTR_RO(childless_, showme); +CONFIGFS_ATTR(childless_, storeme); +CONFIGFS_ATTR_RO(childless_, description); + +static struct configfs_attribute *childless_attrs[] = { + &childless_attr_showme, + &childless_attr_storeme, + &childless_attr_description, + NULL, +}; + +static struct config_item_type childless_type = { + .ct_attrs = childless_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct childless childless_subsys = { + .subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "01-childless", + .ci_type = &childless_type, + }, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 02-simple-children + * + * This example merely has a simple one-attribute child. Note that + * there is no extra attribute structure, as the child's attribute is + * known from the get-go. Also, there is no container for the + * subsystem, as it has no attributes of its own. + */ + +struct simple_child { + struct config_item item; + int storeme; +}; + +static inline struct simple_child *to_simple_child(struct config_item *item) +{ + return item ? container_of(item, struct simple_child, item) : NULL; +} + +static ssize_t simple_child_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_simple_child(item)->storeme); +} + +static ssize_t simple_child_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct simple_child *simple_child = to_simple_child(item); + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + simple_child->storeme = tmp; + + return count; +} + +CONFIGFS_ATTR(simple_child_, storeme); + +static struct configfs_attribute *simple_child_attrs[] = { + &simple_child_attr_storeme, + NULL, +}; + +static void simple_child_release(struct config_item *item) +{ + kfree(to_simple_child(item)); +} + +static struct configfs_item_operations simple_child_item_ops = { + .release = simple_child_release, +}; + +static struct config_item_type simple_child_type = { + .ct_item_ops = &simple_child_item_ops, + .ct_attrs = simple_child_attrs, + .ct_owner = THIS_MODULE, +}; + + +struct simple_children { + struct config_group group; +}; + +static inline struct simple_children *to_simple_children(struct config_item *item) +{ + return item ? container_of(to_config_group(item), + struct simple_children, group) : NULL; +} + +static struct config_item *simple_children_make_item(struct config_group *group, + const char *name) +{ + struct simple_child *simple_child; + + simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); + if (!simple_child) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&simple_child->item, name, + &simple_child_type); + + simple_child->storeme = 0; + + return &simple_child->item; +} + +static ssize_t simple_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[02-simple-children]\n" +"\n" +"This subsystem allows the creation of child config_items. These\n" +"items have only one attribute that is readable and writeable.\n"); +} + +CONFIGFS_ATTR_RO(simple_children_, description); + +static struct configfs_attribute *simple_children_attrs[] = { + &simple_children_attr_description, + NULL, +}; + +static void simple_children_release(struct config_item *item) +{ + kfree(to_simple_children(item)); +} + +static struct configfs_item_operations simple_children_item_ops = { + .release = simple_children_release, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations simple_children_group_ops = { + .make_item = simple_children_make_item, +}; + +static struct config_item_type simple_children_type = { + .ct_item_ops = &simple_children_item_ops, + .ct_group_ops = &simple_children_group_ops, + .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem simple_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "02-simple-children", + .ci_type = &simple_children_type, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 03-group-children + * + * This example reuses the simple_children group from above. However, + * the simple_children group is not the subsystem itself, it is a + * child of the subsystem. Creation of a group in the subsystem creates + * a new simple_children group. That group can then have simple_child + * children of its own. + */ + +static struct config_group *group_children_make_group( + struct config_group *group, const char *name) +{ + struct simple_children *simple_children; + + simple_children = kzalloc(sizeof(struct simple_children), + GFP_KERNEL); + if (!simple_children) + return ERR_PTR(-ENOMEM); + + config_group_init_type_name(&simple_children->group, name, + &simple_children_type); + + return &simple_children->group; +} + +static ssize_t group_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[03-group-children]\n" +"\n" +"This subsystem allows the creation of child config_groups. These\n" +"groups are like the subsystem simple-children.\n"); +} + +CONFIGFS_ATTR_RO(group_children_, description); + +static struct configfs_attribute *group_children_attrs[] = { + &group_children_attr_description, + NULL, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations group_children_group_ops = { + .make_group = group_children_make_group, +}; + +static struct config_item_type group_children_type = { + .ct_group_ops = &group_children_group_ops, + .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem group_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "03-group-children", + .ci_type = &group_children_type, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * We're now done with our subsystem definitions. + * For convenience in this module, here's a list of them all. It + * allows the init function to easily register them. Most modules + * will only have one subsystem, and will only call register_subsystem + * on it directly. + */ +static struct configfs_subsystem *example_subsys[] = { + &childless_subsys.subsys, + &simple_children_subsys, + &group_children_subsys, + NULL, +}; + +static int __init configfs_example_init(void) +{ + int ret; + int i; + struct configfs_subsystem *subsys; + + for (i = 0; example_subsys[i]; i++) { + subsys = example_subsys[i]; + + config_group_init(&subsys->su_group); + mutex_init(&subsys->su_mutex); + ret = configfs_register_subsystem(subsys); + if (ret) { + printk(KERN_ERR "Error %d while registering subsystem %s\n", + ret, + subsys->su_group.cg_item.ci_namebuf); + goto out_unregister; + } + } + + return 0; + +out_unregister: + for (i--; i >= 0; i--) + configfs_unregister_subsystem(example_subsys[i]); + + return ret; +} + +static void __exit configfs_example_exit(void) +{ + int i; + + for (i = 0; example_subsys[i]; i++) + configfs_unregister_subsystem(example_subsys[i]); +} + +module_init(configfs_example_init); +module_exit(configfs_example_exit); +MODULE_LICENSE("GPL"); -- cgit v1.2.3