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authorAmir Goldstein <amir73il@gmail.com>2018-04-20 16:10:51 -0700
committerJan Kara <jack@suse.cz>2018-05-18 14:58:22 +0200
commitd9a6f30bb89309a7f2473028a00b83b020049cb4 (patch)
tree0ea2cfa88eec367ab6c45cb592fb51014d81176b /fs/notify
parent5b0457ad021f3f7e3d9f4b84e7c3080748f383f8 (diff)
downloadlinux-d9a6f30bb89309a7f2473028a00b83b020049cb4.tar.bz2
fsnotify: introduce marks iteration helpers
Introduce helpers fsnotify_iter_select_report_types() 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@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/fsnotify.c74
1 files changed, 49 insertions, 25 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 9a63cf07f858..98e91037b11d 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -261,6 +261,53 @@ static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
}
/*
+ * iter_info is a multi head priority queue of marks.
+ * Pick a subset of marks from queue heads, all with the
+ * same group and set the report_mask for selected subset.
+ * Returns the report_mask of the selected subset.
+ */
+static unsigned int fsnotify_iter_select_report_types(
+ struct fsnotify_iter_info *iter_info)
+{
+ struct fsnotify_mark *inode_mark = iter_info->inode_mark;
+ struct fsnotify_mark *vfsmount_mark = iter_info->vfsmount_mark;
+ int cmp;
+
+ if (!inode_mark && !vfsmount_mark)
+ return 0;
+
+ if (inode_mark && vfsmount_mark) {
+ cmp = fsnotify_compare_groups(inode_mark->group,
+ vfsmount_mark->group);
+ } else {
+ cmp = inode_mark ? -1 : 1;
+ }
+
+ iter_info->report_mask = 0;
+ if (cmp <= 0)
+ iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;
+ if (cmp >= 0)
+ iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
+
+ return iter_info->report_mask;
+}
+
+/*
+ * Pop from iter_info multi head queue, the marks that were iterated in the
+ * current iteration step.
+ */
+static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
+{
+ if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)
+ iter_info->inode_mark =
+ fsnotify_next_mark(iter_info->inode_mark);
+
+ if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)
+ iter_info->vfsmount_mark =
+ fsnotify_next_mark(iter_info->vfsmount_mark);
+}
+
+/*
* 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
@@ -321,37 +368,14 @@ 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.inode_mark || iter_info.vfsmount_mark) {
- struct fsnotify_mark *inode_mark = iter_info.inode_mark;
- struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark;
- int cmp;
-
- if (inode_mark && vfsmount_mark) {
- cmp = fsnotify_compare_groups(inode_mark->group,
- vfsmount_mark->group);
- } else {
- cmp = inode_mark ? -1 : 1;
- }
-
- iter_info.report_mask = 0;
- if (cmp <= 0)
- iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;
- if (cmp >= 0)
- iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;
-
+ while (fsnotify_iter_select_report_types(&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.report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)
- iter_info.inode_mark =
- fsnotify_next_mark(iter_info.inode_mark);
-
- if (iter_info.report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)
- iter_info.vfsmount_mark =
- fsnotify_next_mark(iter_info.vfsmount_mark);
+ fsnotify_iter_next(&iter_info);
}
ret = 0;
out: