diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/kernfs.h | 8 | ||||
| -rw-r--r-- | include/linux/sysfs.h | 9 |
2 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 30faf797c2c3..d4e01b358341 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -179,6 +179,7 @@ struct kernfs_open_file { struct mutex mutex; int event; struct list_head list; + char *prealloc_buf; size_t atomic_write_len; bool mmapped; @@ -214,6 +215,13 @@ struct kernfs_ops { * larger ones are rejected with -E2BIG. */ size_t atomic_write_len; + /* + * "prealloc" causes a buffer to be allocated at open for + * all read/write requests. As ->seq_show uses seq_read() + * which does its own allocation, it is incompatible with + * ->prealloc. Provide ->read and ->write with ->prealloc. + */ + bool prealloc; ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes, loff_t off); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index f97d0dbb59fa..ddad16148bd6 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -70,6 +70,8 @@ struct attribute_group { * for examples.. */ +#define SYSFS_PREALLOC 010000 + #define __ATTR(_name, _mode, _show, _store) { \ .attr = {.name = __stringify(_name), \ .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ @@ -77,6 +79,13 @@ struct attribute_group { .store = _store, \ } +#define __ATTR_PREALLOC(_name, _mode, _show, _store) { \ + .attr = {.name = __stringify(_name), \ + .mode = SYSFS_PREALLOC | VERIFY_OCTAL_PERMISSIONS(_mode) },\ + .show = _show, \ + .store = _store, \ +} + #define __ATTR_RO(_name) { \ .attr = { .name = __stringify(_name), .mode = S_IRUGO }, \ .show = _name##_show, \ |