[PATCH 2/2] fsnotify: refactor mask filtering in send_to_group()

From: Csaba Henk
Date: Sat Aug 28 2010 - 15:26:04 EST


- isolate filtering logic to reduce code duplication
- the case when only one mark is passed was not handled correctly:
in this case the mask variable for the other mark was not
filtered, giving therefore a green way, regardless the mask of
the mark which was actually there to be tested

Signed-off-by: Csaba Henk <csaba@xxxxxxxxxxx>
---
fs/notify/fsnotify.c | 44 +++++++++++++++++---------------------------
1 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 6657315..ece4bd6 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -140,6 +140,20 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
}
EXPORT_SYMBOL_GPL(__fsnotify_parent);

+static int check_mark_mask(struct fsnotify_mark *mark, __u32 *mask)
+{
+ if (!mark)
+ return 0;
+
+ if ((*mask & FS_MODIFY) &&
+ !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ mark->ignored_mask = 0;
+ else
+ *mask &= ~mark->ignored_mask;
+
+ return *mask & mark->mask;
+}
+
static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
struct fsnotify_mark *inode_mark,
struct fsnotify_mark *vfsmount_mark,
@@ -149,8 +163,7 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
struct fsnotify_event **event)
{
struct fsnotify_group *group;
- __u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
- __u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+ __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);

if (inode_mark)
group = inode_mark->group;
@@ -164,31 +177,8 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
__func__, group, to_tell, mnt, inode_mark, vfsmount_mark, mask,
data, data_is, cookie, *event);

- /* clear ignored on inode modification */
- if (mask & FS_MODIFY) {
- if (inode_mark &&
- !(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
- inode_mark->ignored_mask = 0;
- if (vfsmount_mark &&
- !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
- vfsmount_mark->ignored_mask = 0;
- }
-
- /* does the inode mark tell us to do something? */
- if (inode_mark) {
- inode_test_mask &= inode_mark->mask;
- inode_test_mask &= ~inode_mark->ignored_mask;
- }
-
- /* does the vfsmount_mark tell us to do something? */
- if (vfsmount_mark) {
- vfsmount_test_mask &= vfsmount_mark->mask;
- vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
- if (inode_mark)
- vfsmount_test_mask &= ~inode_mark->ignored_mask;
- }
-
- if (!inode_test_mask && !vfsmount_test_mask)
+ if (!(check_mark_mask(inode_mark, &test_mask) ||
+ check_mark_mask(vfsmount_mark, &test_mask)))
return 0;

if (group->ops->should_send_event(group, to_tell, inode_mark,
--
1.7.2.2

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