fanotify: allow users to set an ignored_mask
Change the sys_fanotify_mark() system call so users can set ignored_masks
on inodes. Remember, if a user new sets a real mask, and only sets ignored
masks, the ignore will never be pinned in memory. Thus ignored_masks can
be lost under memory pressure and the user may again get events they
previously thought were ignored.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 3320f0c..ad02d47 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -296,13 +296,20 @@
return ret;
}
-static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, __u32 mask)
+static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
+ __u32 mask,
+ unsigned int flags)
{
__u32 oldmask;
spin_lock(&fsn_mark->lock);
- oldmask = fsn_mark->mask;
- fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
+ if (!(flags & FAN_MARK_IGNORED_MASK)) {
+ oldmask = fsn_mark->mask;
+ fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
+ } else {
+ oldmask = fsn_mark->ignored_mask;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask));
+ }
spin_unlock(&fsn_mark->lock);
if (!(oldmask & ~mask))
@@ -312,7 +319,8 @@
}
static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask)
+ struct vfsmount *mnt, __u32 mask,
+ unsigned int flags)
{
struct fsnotify_mark *fsn_mark = NULL;
__u32 removed;
@@ -321,7 +329,7 @@
if (!fsn_mark)
return -ENOENT;
- removed = fanotify_mark_remove_from_mask(fsn_mark, mask);
+ removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
fsnotify_put_mark(fsn_mark);
if (removed & group->mask)
fsnotify_recalc_group_mask(group);
@@ -332,7 +340,8 @@
}
static int fanotify_remove_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask)
+ struct inode *inode, __u32 mask,
+ unsigned int flags)
{
struct fsnotify_mark *fsn_mark = NULL;
__u32 removed;
@@ -341,7 +350,7 @@
if (!fsn_mark)
return -ENOENT;
- removed = fanotify_mark_remove_from_mask(fsn_mark, mask);
+ removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
/* matches the fsnotify_find_inode_mark() */
fsnotify_put_mark(fsn_mark);
@@ -353,20 +362,28 @@
return 0;
}
-static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, __u32 mask)
+static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
+ __u32 mask,
+ unsigned int flags)
{
__u32 oldmask;
spin_lock(&fsn_mark->lock);
- oldmask = fsn_mark->mask;
- fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
+ if (!(flags & FAN_MARK_IGNORED_MASK)) {
+ oldmask = fsn_mark->mask;
+ fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
+ } else {
+ oldmask = fsn_mark->ignored_mask;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask));
+ }
spin_unlock(&fsn_mark->lock);
return mask & ~oldmask;
}
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask)
+ struct vfsmount *mnt, __u32 mask,
+ unsigned int flags)
{
struct fsnotify_mark *fsn_mark;
__u32 added;
@@ -386,7 +403,7 @@
return ret;
}
}
- added = fanotify_mark_add_to_mask(fsn_mark, mask);
+ added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
fsnotify_put_mark(fsn_mark);
if (added) {
if (added & ~group->mask)
@@ -398,7 +415,8 @@
}
static int fanotify_add_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask)
+ struct inode *inode, __u32 mask,
+ unsigned int flags)
{
struct fsnotify_mark *fsn_mark;
__u32 added;
@@ -420,7 +438,7 @@
return ret;
}
}
- added = fanotify_mark_add_to_mask(fsn_mark, mask);
+ added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
fsnotify_put_mark(fsn_mark);
if (added) {
if (added & ~group->mask)
@@ -528,15 +546,15 @@
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
case FAN_MARK_ADD:
if (flags & FAN_MARK_MOUNT)
- ret = fanotify_add_vfsmount_mark(group, mnt, mask);
+ ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
else
- ret = fanotify_add_inode_mark(group, inode, mask);
+ ret = fanotify_add_inode_mark(group, inode, mask, flags);
break;
case FAN_MARK_REMOVE:
if (flags & FAN_MARK_MOUNT)
- ret = fanotify_remove_vfsmount_mark(group, mnt, mask);
+ ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
else
- ret = fanotify_remove_inode_mark(group, inode, mask);
+ ret = fanotify_remove_inode_mark(group, inode, mask, flags);
break;
default:
ret = -EINVAL;