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authorLinus Torvalds <torvalds@linux-foundation.org>2008-08-01 11:54:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-01 11:54:05 -0700
commit63a16f90167850010864a9e8ebb71d216983090f (patch)
treec4b284cc596421ac8100e0ad3b2f56ead4563d2d /include
parent5adf2b03d97111c8955495ba11e8b7db27df8695 (diff)
parentc259ae52e204d42f8b2d484c85517a4c367030e1 (diff)
downloadlinux-63a16f90167850010864a9e8ebb71d216983090f.tar.bz2
Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: [PATCH] ocfs2: Release mutex in error handling code [PATCH] ocfs2: Fix oops when racing files truncates with writes into an mmap region [PATCH 2/2] ocfs2: Fix race between mount and recovery [PATCH 1/2] ocfs2: Add counter in struct ocfs2_dinode to track journal replays [PATCH] configfs: Convenience macros for attribute definition. [PATCH] configfs: Pin configfs subsystems separately from new config_items. [PATCH] configfs: Fix open directory making rmdir() fail [PATCH] configfs: Lock new directory inodes before removing on cleanup after failure [PATCH] configfs: Prevent userspace from creating new entries under attaching directories [PATCH] configfs: Fix failing symlink() making rmdir() fail [PATCH] configfs: Fix symlink() to a removing item [PATCH] configfs: Include linux/err.h in linux/configfs.h
Diffstat (limited to 'include')
-rw-r--r--include/linux/configfs.h68
1 files changed, 66 insertions, 2 deletions
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index d62c19ff041c..7f627775c947 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -40,6 +40,7 @@
#include <linux/list.h>
#include <linux/kref.h>
#include <linux/mutex.h>
+#include <linux/err.h>
#include <asm/atomic.h>
@@ -129,8 +130,25 @@ struct configfs_attribute {
/*
* Users often need to create attribute structures for their configurable
* attributes, containing a configfs_attribute member and function pointers
- * for the show() and store() operations on that attribute. They can use
- * this macro (similar to sysfs' __ATTR) to make defining attributes easier.
+ * for the show() and store() operations on that attribute. If they don't
+ * need anything else on the extended attribute structure, they can use
+ * this macro to define it The argument _item is the name of the
+ * config_item structure.
+ */
+#define CONFIGFS_ATTR_STRUCT(_item) \
+struct _item##_attribute { \
+ struct configfs_attribute attr; \
+ ssize_t (*show)(struct _item *, char *); \
+ ssize_t (*store)(struct _item *, const char *, size_t); \
+}
+
+/*
+ * With the extended attribute structure, users can use this macro
+ * (similar to sysfs' __ATTR) to make defining attributes easier.
+ * An example:
+ * #define MYITEM_ATTR(_name, _mode, _show, _store) \
+ * struct myitem_attribute childless_attr_##_name = \
+ * __CONFIGFS_ATTR(_name, _mode, _show, _store)
*/
#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \
{ \
@@ -142,6 +160,52 @@ struct configfs_attribute {
.show = _show, \
.store = _store, \
}
+/* Here is a readonly version, only requiring a show() operation */
+#define __CONFIGFS_ATTR_RO(_name, _show) \
+{ \
+ .attr = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = 0444, \
+ .ca_owner = THIS_MODULE, \
+ }, \
+ .show = _show, \
+}
+
+/*
+ * With these extended attributes, the simple show_attribute() and
+ * store_attribute() operations need to call the show() and store() of the
+ * attributes. This is a common pattern, so we provide a macro to define
+ * them. The argument _item is the name of the config_item structure.
+ * This macro expects the attributes to be named "struct <name>_attribute"
+ * and the function to_<name>() to exist;
+ */
+#define CONFIGFS_ATTR_OPS(_item) \
+static ssize_t _item##_attr_show(struct config_item *item, \
+ struct configfs_attribute *attr, \
+ char *page) \
+{ \
+ struct _item *_item = to_##_item(item); \
+ struct _item##_attribute *_item##_attr = \
+ container_of(attr, struct _item##_attribute, attr); \
+ ssize_t ret = 0; \
+ \
+ if (_item##_attr->show) \
+ ret = _item##_attr->show(_item, page); \
+ return ret; \
+} \
+static ssize_t _item##_attr_store(struct config_item *item, \
+ struct configfs_attribute *attr, \
+ const char *page, size_t count) \
+{ \
+ struct _item *_item = to_##_item(item); \
+ struct _item##_attribute *_item##_attr = \
+ container_of(attr, struct _item##_attribute, attr); \
+ ssize_t ret = -EINVAL; \
+ \
+ if (_item##_attr->store) \
+ ret = _item##_attr->store(_item, page, count); \
+ return ret; \
+}
/*
* If allow_link() exists, the item can symlink(2) out to other