diff options
| -rw-r--r-- | fs/sysfs/file.c | 14 | ||||
| -rw-r--r-- | fs/sysfs/group.c | 83 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 2 | ||||
| -rw-r--r-- | include/linux/sysfs.h | 4 |
4 files changed, 85 insertions, 18 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index ade9a7e6a75..dbdfabbfd60 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -477,11 +477,10 @@ const struct file_operations sysfs_file_operations = { .poll = sysfs_poll, }; - -int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, - int type) +int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, mode_t amode) { - umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; + umode_t mode = (amode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; int rc; @@ -502,6 +501,13 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, } +int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, + int type) +{ + return sysfs_add_file_mode(dir_sd, attr, type, attr->mode); +} + + /** * sysfs_create_file - create an attribute file for an object. * @kobj: object we're creating for. diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 47790491503..eeba38417b1 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -23,35 +23,50 @@ static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, int i; for (i = 0, attr = grp->attrs; *attr; i++, attr++) - if (!grp->is_visible || - grp->is_visible(kobj, *attr, i)) - sysfs_hash_and_remove(dir_sd, (*attr)->name); + sysfs_hash_and_remove(dir_sd, (*attr)->name); } static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, - const struct attribute_group *grp) + const struct attribute_group *grp, int update) { struct attribute *const* attr; int error = 0, i; - for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) - if (!grp->is_visible || - grp->is_visible(kobj, *attr, i)) - error |= - sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR); + for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) { + mode_t mode = 0; + + /* in update mode, we're changing the permissions or + * visibility. Do this by first removing then + * re-adding (if required) the file */ + if (update) + sysfs_hash_and_remove(dir_sd, (*attr)->name); + if (grp->is_visible) { + mode = grp->is_visible(kobj, *attr, i); + if (!mode) + continue; + } + error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR, + (*attr)->mode | mode); + if (unlikely(error)) + break; + } if (error) remove_files(dir_sd, kobj, grp); return error; } -int sysfs_create_group(struct kobject * kobj, - const struct attribute_group * grp) +static int internal_create_group(struct kobject *kobj, int update, + const struct attribute_group *grp) { struct sysfs_dirent *sd; int error; - BUG_ON(!kobj || !kobj->sd); + BUG_ON(!kobj || (!update && !kobj->sd)); + + /* Updates may happen before the object has been instantiated */ + if (unlikely(update && !kobj->sd)) + return -EINVAL; if (grp->name) { error = sysfs_create_subdir(kobj, grp->name, &sd); @@ -60,7 +75,7 @@ int sysfs_create_group(struct kobject * kobj, } else sd = kobj->sd; sysfs_get(sd); - error = create_files(sd, kobj, grp); + error = create_files(sd, kobj, grp, update); if (error) { if (grp->name) sysfs_remove_subdir(sd); @@ -69,6 +84,47 @@ int sysfs_create_group(struct kobject * kobj, return error; } +/** + * sysfs_create_group - given a directory kobject, create an attribute group + * @kobj: The kobject to create the group on + * @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. + */ +int sysfs_create_group(struct kobject *kobj, + const struct attribute_group *grp) +{ + return internal_create_group(kobj, 0, grp); +} + +/** + * sysfs_update_group - given a directory kobject, create an attribute group + * @kobj: The kobject to create the group on + * @grp: The attribute group to create + * + * This function updates an attribute group. Unlike + * sysfs_create_group(), it will explicitly not warn or error if any + * of the attribute files being created already exist. Furthermore, + * if the visibility of the files has changed through the is_visible() + * callback, it will update the permissions and add or remove the + * relevant files. + * + * The primary use for this function is to call it after making a change + * that affects group visibility. + * + * Returns 0 on success or error. + */ +int sysfs_update_group(struct kobject *kobj, + const struct attribute_group *grp) +{ + return internal_create_group(kobj, 1, grp); +} + + + void sysfs_remove_group(struct kobject * kobj, const struct attribute_group * grp) { @@ -95,4 +151,5 @@ void sysfs_remove_group(struct kobject * kobj, EXPORT_SYMBOL_GPL(sysfs_create_group); +EXPORT_SYMBOL_GPL(sysfs_update_group); EXPORT_SYMBOL_GPL(sysfs_remove_group); diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index ff17f8da9b4..ce4e15f8aae 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -154,6 +154,8 @@ extern const struct file_operations sysfs_file_operations; int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, int type); +int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, mode_t amode); /* * bin.c */ diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 03378e3515b..add3c5a4082 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -32,7 +32,7 @@ struct attribute { struct attribute_group { const char *name; - int (*is_visible)(struct kobject *, + mode_t (*is_visible)(struct kobject *, struct attribute *, int); struct attribute **attrs; }; @@ -105,6 +105,8 @@ void sysfs_remove_link(struct kobject *kobj, const char *name); int __must_check sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp); +int sysfs_update_group(struct kobject *kobj, + const struct attribute_group *grp); void sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp); int sysfs_add_file_to_group(struct kobject *kobj, |