diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 6b7652fb805057..d1995e2d6c943a 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -463,6 +463,8 @@ struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, kn = kernfs_find_and_get(kobj->sd, attr->name); if (kn) kernfs_break_active_protection(kn); + else + kobject_put(kobj); return kn; } EXPORT_SYMBOL_GPL(sysfs_break_active_protection); @@ -783,3 +785,30 @@ int sysfs_emit_at(char *buf, int at, const char *fmt, ...) return len; } EXPORT_SYMBOL_GPL(sysfs_emit_at); + +/** + * sysfs_bin_attr_simple_read - read callback to simply copy from memory. + * @file: attribute file which is being read. + * @kobj: object to which the attribute belongs. + * @attr: attribute descriptor. + * @buf: destination buffer. + * @off: offset in bytes from which to read. + * @count: maximum number of bytes to read. + * + * Simple ->read() callback for bin_attributes backed by a buffer in memory. + * The @private and @size members in struct bin_attribute must be set to the + * buffer's location and size before the bin_attribute is created in sysfs. + * + * Bounds check for @off and @count is done in sysfs_kf_bin_read(). + * Negative value check for @off is done in vfs_setpos() and default_llseek(). + * + * Returns number of bytes written to @buf. + */ +ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count) +{ + memcpy(buf, attr->private + off, count); + return count; +} +EXPORT_SYMBOL_GPL(sysfs_bin_attr_simple_read); |