Introduce helpers fsnotify_iter_first() and fsnotify_iter_next()
to abstract the inode / vfsmount marks merged list iteration.
This is a preparation patch before generalizing mark list
iteration to more mark object types (i.e. super block marks).
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/notify/fsnotify.c | 68 +++++++++++++++++++++++++++++++++-------------------
1 file changed, 44 insertions(+), 24 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index cb0afa664057..665f681dd913 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -261,6 +261,48 @@ static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
}
/*
+ * iter_info is a multi head priority queue of marks.
+ * fsnotify_iter_first() picks a subset of marks from queue heads, all with the
+ * same priority and clears the type_mask for other marks.
+ * Returns the type_mask of the chosen subset.
+ */
+static unsigned int fsnotify_iter_first(struct fsnotify_iter_info *iter_info)
+{
+ struct fsnotify_mark *inode_mark = iter_info->inode_mark;
+ struct fsnotify_mark *vfsmount_mark = iter_info->vfsmount_mark;
+
+ if (inode_mark && vfsmount_mark) {
+ int cmp = fsnotify_compare_groups(inode_mark->group,
+ vfsmount_mark->group);
+ if (cmp > 0)
+ iter_info->type_mask &= ~FSNOTIFY_OBJ_TYPE_INODE_FL;
+ else if (cmp < 0)
+ iter_info->type_mask &= ~FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
+ }
+
+ return iter_info->type_mask;
+}
+
+/*
+ * Pop from iter_info multi head queue, the marks that were iterated in the
+ * current iteration step and set type_mask for all non NULL marks.
+ */
+static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
+{
+ if (iter_info->type_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)
+ fsnotify_iter_set_inode_mark(iter_info,
+ fsnotify_next_mark(iter_info->inode_mark));
+ else if (iter_info->inode_mark)
+ iter_info->type_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;
+
+ if (iter_info->type_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)
+ fsnotify_iter_set_vfsmount_mark(iter_info,
+ fsnotify_next_mark(iter_info->vfsmount_mark));
+ else if (iter_info->vfsmount_mark)
+ iter_info->type_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
+}
+
+/*
* This is the main call to fsnotify. The VFS calls into hook specific functions
* in linux/fsnotify.h. Those functions then in turn call here. Here will call
* out to all of the registered fsnotify_group. Those groups can then use the
@@ -321,36 +363,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
* ignore masks are properly reflected for mount mark notifications.
* That's why this traversal is so complicated...
*/
- while (iter_info.type_mask) {
- struct fsnotify_mark *inode_mark = iter_info.inode_mark;
- struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark;
-
- if (inode_mark && vfsmount_mark) {
- int cmp = fsnotify_compare_groups(inode_mark->group,
- vfsmount_mark->group);
- if (cmp > 0)
- iter_info.type_mask &= ~FSNOTIFY_OBJ_TYPE_INODE_FL;
- else if (cmp < 0)
- iter_info.type_mask &= ~FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
- }
-
+ while (fsnotify_iter_first(&iter_info)) {
ret = send_to_group(to_tell, mask, data, data_is, cookie,
file_name, &iter_info);
if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
goto out;
- if (iter_info.type_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)
- fsnotify_iter_set_inode_mark(&iter_info,
- fsnotify_next_mark(iter_info.inode_mark));
- else if (iter_info.inode_mark)
- iter_info.type_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;
-
- if (iter_info.type_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)
- fsnotify_iter_set_vfsmount_mark(&iter_info,
- fsnotify_next_mark(iter_info.vfsmount_mark));
- else if (iter_info.vfsmount_mark)
- iter_info.type_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
+ fsnotify_iter_next(&iter_info);
}
ret = 0;
out:
--
2.7.4
