From 7f5028cf6190407b7a632b0f30b83187577824cc Mon Sep 17 00:00:00 2001 From: Emilio López Date: Mon, 21 Sep 2015 10:38:20 -0300 Subject: sysfs: Support is_visible() on binary attributes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit According to the sysfs header file: "The returned value will replace static permissions defined in struct attribute or struct bin_attribute." but this isn't the case, as is_visible is only called on struct attribute only. This patch introduces a new is_bin_visible() function to implement the same functionality for binary attributes, and updates documentation accordingly. Note that to keep functionality and code similar to that of normal attributes, the mode is now checked as well to ensure it contains only read/write permissions or SYSFS_PREALLOC. Reviewed-by: Guenter Roeck Signed-off-by: Emilio López Acked-by: Greg Kroah-Hartman Signed-off-by: Olof Johansson --- include/linux/sysfs.h | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'include/linux/sysfs.h') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 9f65758311a4..2f66050d073b 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -64,10 +64,18 @@ do { \ * a new subdirectory with this name. * @is_visible: Optional: Function to return permissions associated with an * attribute of the group. Will be called repeatedly for each - * attribute in the group. Only read/write permissions as well as - * SYSFS_PREALLOC are accepted. Must return 0 if an attribute is - * not visible. The returned value will replace static permissions - * defined in struct attribute or struct bin_attribute. + * non-binary attribute in the group. Only read/write + * permissions as well as SYSFS_PREALLOC are accepted. Must + * return 0 if an attribute is not visible. The returned value + * will replace static permissions defined in struct attribute. + * @is_bin_visible: + * Optional: Function to return permissions associated with a + * binary attribute of the group. Will be called repeatedly + * for each binary attribute in the group. Only read/write + * permissions as well as SYSFS_PREALLOC are accepted. Must + * return 0 if a binary attribute is not visible. The returned + * value will replace static permissions defined in + * struct bin_attribute. * @attrs: Pointer to NULL terminated list of attributes. * @bin_attrs: Pointer to NULL terminated list of binary attributes. * Either attrs or bin_attrs or both must be provided. @@ -76,6 +84,8 @@ struct attribute_group { const char *name; umode_t (*is_visible)(struct kobject *, struct attribute *, int); + umode_t (*is_bin_visible)(struct kobject *, + struct bin_attribute *, int); struct attribute **attrs; struct bin_attribute **bin_attrs; }; -- cgit v1.2.3 From 37c1c04cca920de8a68285751b2c7b3d937ad50c Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Wed, 22 Apr 2015 19:36:06 +0300 Subject: sysfs: added __compat_only_sysfs_link_entry_to_kobj() Added a new function __compat_only_sysfs_link_group_to_kobj() that adds a symlink from attribute or group to a kobject. This needed for maintaining backwards compatibility with PPI attributes in the TPM driver. Signed-off-by: Jarkko Sakkinen Signed-off-by: Peter Huewe --- fs/sysfs/group.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 11 +++++++++++ 2 files changed, 55 insertions(+) (limited to 'include/linux/sysfs.h') diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 39a019936768..e1236594fffe 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -352,3 +352,47 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, } } EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); + +/** + * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing + * to a group or an attribute + * @kobj: The kobject containing the group. + * @target_kobj: The target kobject. + * @target_name: The name of the target group or attribute. + */ +int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, + struct kobject *target_kobj, + const char *target_name) +{ + struct kernfs_node *target; + struct kernfs_node *entry; + struct kernfs_node *link; + + /* + * We don't own @target_kobj and it may be removed at any time. + * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir() + * for details. + */ + spin_lock(&sysfs_symlink_target_lock); + target = target_kobj->sd; + if (target) + kernfs_get(target); + spin_unlock(&sysfs_symlink_target_lock); + if (!target) + return -ENOENT; + + entry = kernfs_find_and_get(target_kobj->sd, target_name); + if (!entry) { + kernfs_put(target); + return -ENOENT; + } + + link = kernfs_create_link(kobj->sd, target_name, entry); + if (IS_ERR(link) && PTR_ERR(link) == -EEXIST) + sysfs_warn_dup(kobj->sd, target_name); + + kernfs_put(entry); + kernfs_put(target); + return IS_ERR(link) ? PTR_ERR(link) : 0; +} +EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 9f65758311a4..ea090eaf468c 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -268,6 +268,9 @@ int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, struct kobject *target, const char *link_name); void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, const char *link_name); +int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, + struct kobject *target_kobj, + const char *target_name); void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); @@ -451,6 +454,14 @@ static inline void sysfs_remove_link_from_group(struct kobject *kobj, { } +static inline int __compat_only_sysfs_link_entry_to_kobj( + struct kobject *kobj, + struct kobject *target_kobj, + const char *target_name) +{ + return 0; +} + static inline void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { -- cgit v1.2.3