Many drivers create additional driver-specific device attributes when binding to the device and providing managed version of sysfs_create_group() will simplify unbinding and error handling in probe path for such drivers.
Signed-off-by: Dmitry Torokhov <[email protected]> --- fs/sysfs/group.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 10 ++++ 2 files changed, 134 insertions(+) diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 39a0199..9511437 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,6 +13,7 @@ #include <linux/kobject.h> #include <linux/module.h> #include <linux/dcache.h> +#include <linux/device.h> #include <linux/namei.h> #include <linux/err.h> #include "sysfs.h" @@ -352,3 +353,126 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, } } EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); + +struct sysfs_group_devres { + const struct attribute_group *group; +}; + +static int devm_sysfs_group_match(struct device *dev, void *res, void *data) +{ + return ((struct sysfs_group_devres *)res)->group == data; +} + +static void devm_sysfs_group_remove_group(struct device *dev, void *res) +{ + struct sysfs_group_devres *devres = res; + const struct attribute_group *group = devres->group; + + dev_dbg(dev, "%s: removing group %p\n", __func__, group); + sysfs_remove_group(&dev->kobj, group); +} + +/** + * devm_sysfs_create_group - given a device, create a managed attribute group + * @dev: The device to create the group for + * @grp: The attribute group to create + * + * This function creates a group for the first time. It will explicitly + * warn and error if any of the attribute files being created already exist. + * + * Returns 0 on success or error code on failure. + */ +int devm_sysfs_create_group(struct device *dev, + const struct attribute_group *grp) +{ + struct sysfs_group_devres *devres; + int error; + + devres = devres_alloc(devm_sysfs_group_remove_group, + sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + error = sysfs_create_group(&dev->kobj, grp); + if (error) { + devres_free(devres); + return error; + } + + devres_add(dev, devres); + return 0; +} +EXPORT_SYMBOL_GPL(devm_sysfs_create_group); + +/** + * devm_sysfs_create_groups - create a bunch of managed attribute groups + * @dev: The device to create the group for + * @groups: The attribute groups to create, NULL terminated + * + * This function creates a bunch of managed attribute groups. If an error + * occurs when creating a group, all previously created groups will be + * removed, unwinding everything back to the original state when this + * function was called. It will explicitly warn and error if any of the + * attribute files being created already exist. + * + * Returns 0 on success or error code from sysfs_create_group on failure. + */ +int devm_sysfs_create_groups(struct device *dev, + const struct attribute_group **groups) +{ + int error; + int i; + + if (!groups) + return 0; + + for (i = 0; groups[i]; i++) { + error = devm_sysfs_create_group(dev, groups[i]); + if (error) { + while (--i >= 0) + devm_sysfs_remove_group(dev, groups[i]); + return error; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(devm_sysfs_create_groups); + +/** + * devm_sysfs_remove_group: remove a managed group from a device + * @dev: device to remove the group from + * @grp: group to remove + * + * This function removes a group of attributes from a device. The attributes + * previously have to have been created for this group, otherwise it will fail. + */ +void devm_sysfs_remove_group(struct device *dev, + const struct attribute_group *grp) +{ + WARN_ON(devres_release(dev, devm_sysfs_group_remove_group, + devm_sysfs_group_match, + /* cast away const */ (void *)grp)); +} +EXPORT_SYMBOL_GPL(devm_sysfs_remove_group); + +/** + * devm_sysfs_remove_groups - remove a list of managed groups + * + * @dev: The device for the groups to be removed from + * @groups: NULL terminated list of groups to be removed + * + * If groups is not NULL, remove the specified groups from the device. + */ +void devm_sysfs_remove_groups(struct device *dev, + const struct attribute_group **groups) +{ + int i; + + if (!groups) + return; + + for (i = 0; groups[i]; i++) + devm_sysfs_remove_group(dev, groups[i]); +} +EXPORT_SYMBOL_GPL(devm_sysfs_remove_groups); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 9f65758..b59a913 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -269,6 +269,16 @@ int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, const char *link_name); +struct device; +int __must_check devm_sysfs_create_group(struct device *dev, + const struct attribute_group *grp); +int __must_check devm_sysfs_create_groups(struct device *dev, + const struct attribute_group **groups); +void devm_sysfs_remove_group(struct device *dev, + const struct attribute_group *grp); +void devm_sysfs_remove_groups(struct device *dev, + const struct attribute_group **groups); + void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); int __must_check sysfs_init(void); -- 1.9.1 -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
