@@ -651,12 +651,13 @@ static int fanotify_find_path(int dfd, const char __user *filename,
}
static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
- __u32 mask,
- unsigned int flags,
- int *destroy)
+ __u32 mask, unsigned int flags,
+ __u32 umask, int *destroy)
{
__u32 oldmask = 0;
+ /* umask bits cannot be removed by user */
+ mask &= ~umask;
spin_lock(&fsn_mark->lock);
if (!(flags & FAN_MARK_IGNORED_MASK)) {
oldmask = fsn_mark->mask;
@@ -664,7 +665,13 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
} else {
fsn_mark->ignored_mask &= ~mask;
}
- *destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
+ /*
+ * We need to keep the mark around even if remaining mask cannot
+ * result in any events (e.g. mask == FAN_ONDIR) to support incremenal
+ * changes to the mask.
+ * Destroy mark when only umask bits remain.
+ */
+ *destroy = !((fsn_mark->mask | fsn_mark->ignored_mask) & ~umask);
spin_unlock(&fsn_mark->lock);
return mask & oldmask;
@@ -672,7 +679,7 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
static int fanotify_remove_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, __u32 mask,
- unsigned int flags)
+ unsigned int flags, __u32 umask)
{
struct fsnotify_mark *fsn_mark = NULL;
__u32 removed;
@@ -686,7 +693,7 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
}
removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
- &destroy_mark);
+ umask, &destroy_mark);
if (removed & fsnotify_conn_mask(fsn_mark->connector))
fsnotify_recalc_mask(fsn_mark->connector);
if (destroy_mark)
@@ -702,25 +709,26 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
struct vfsmount *mnt, __u32 mask,
- unsigned int flags)
+ unsigned int flags, __u32 umask)
{
return fanotify_remove_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
- mask, flags);
+ mask, flags, umask);
}
static int fanotify_remove_sb_mark(struct fsnotify_group *group,
- struct super_block *sb, __u32 mask,
- unsigned int flags)
+ struct super_block *sb, __u32 mask,
+ unsigned int flags, __u32 umask)
{
- return fanotify_remove_mark(group, &sb->s_fsnotify_marks, mask, flags);
+ return fanotify_remove_mark(group, &sb->s_fsnotify_marks, mask,
+ flags, umask);
}
static int fanotify_remove_inode_mark(struct fsnotify_group *group,
struct inode *inode, __u32 mask,
- unsigned int flags)
+ unsigned int flags, __u32 umask)
{
return fanotify_remove_mark(group, &inode->i_fsnotify_marks, mask,
- flags);
+ flags, umask);
}
static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
@@ -1170,13 +1178,13 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
case FAN_MARK_REMOVE:
if (mark_type == FAN_MARK_MOUNT)
ret = fanotify_remove_vfsmount_mark(group, mnt, mask,
- flags);
+ flags, 0);
else if (mark_type == FAN_MARK_FILESYSTEM)
ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask,
- flags);
+ flags, 0);
else
ret = fanotify_remove_inode_mark(group, inode, mask,
- flags);
+ flags, 0);
break;
default:
ret = -EINVAL;
So far, all flags that can be set in an fanotify mark mask can be set explicitly by a call to fanotify_mark(2). Prepare for defining implicit event flags that cannot be set by user with fanotify_mark(2), similar to how inotify/dnotify implicitly set the FS_EVENT_ON_CHILD flag. Implicit event flags cannot be removed by user and mark gets destroyed when only implicit event flags remain in the mask. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/notify/fanotify/fanotify_user.c | 40 ++++++++++++++++++------------ 1 file changed, 24 insertions(+), 16 deletions(-)