Commit 0c6532e4 authored by Eric Paris's avatar Eric Paris

fsnotify: place marks on object in order of group memory address

fsnotify_marks currently are placed on objects (inodes or vfsmounts) in
arbitrary order.  This patch places them in order of the group memory address.
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent c1e5c954
......@@ -174,15 +174,17 @@ void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
}
/*
* Attach an initialized mark to a given group and inode.
* Attach an initialized mark to a given inode.
* These marks may be used for the fsnotify backend to determine which
* event types should be delivered to which group and for which inodes.
* event types should be delivered to which group and for which inodes. These
* marks are ordered according to the group's location in memory.
*/
int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct inode *inode,
int allow_dups)
{
struct fsnotify_mark *lmark = NULL;
struct fsnotify_mark *lmark;
struct hlist_node *node, *last = NULL;
int ret = 0;
mark->flags = FSNOTIFY_MARK_FLAG_INODE;
......@@ -192,21 +194,37 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
spin_lock(&inode->i_lock);
if (!allow_dups)
lmark = fsnotify_find_inode_mark_locked(group, inode);
if (!lmark) {
mark->i.inode = inode;
mark->i.inode = inode;
/* is mark the first mark? */
if (hlist_empty(&inode->i_fsnotify_marks)) {
hlist_add_head(&mark->i.i_list, &inode->i_fsnotify_marks);
goto out;
}
/* should mark be in the middle of the current list? */
hlist_for_each_entry(lmark, node, &inode->i_fsnotify_marks, i.i_list) {
last = node;
if ((lmark->group == group) && !allow_dups) {
ret = -EEXIST;
goto out;
}
fsnotify_recalc_inode_mask_locked(inode);
if (mark->group < lmark->group)
continue;
hlist_add_before(&mark->i.i_list, &lmark->i.i_list);
goto out;
}
BUG_ON(last == NULL);
/* mark should be the last entry. last is the current last entry */
hlist_add_after(last, &mark->i.i_list);
out:
fsnotify_recalc_inode_mask_locked(inode);
spin_unlock(&inode->i_lock);
if (lmark)
ret = -EEXIST;
return ret;
}
......
......@@ -141,34 +141,46 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct vfsmount *mnt,
int allow_dups)
{
struct fsnotify_mark *lmark = NULL;
struct fsnotify_mark *lmark;
struct hlist_node *node, *last = NULL;
int ret = 0;
mark->flags = FSNOTIFY_MARK_FLAG_VFSMOUNT;
/*
* LOCKING ORDER!!!!
* mark->lock
* group->mark_lock
* mnt->mnt_root->d_lock
*/
assert_spin_locked(&mark->lock);
assert_spin_locked(&group->mark_lock);
spin_lock(&mnt->mnt_root->d_lock);
if (!allow_dups)
lmark = fsnotify_find_vfsmount_mark_locked(group, mnt);
if (!lmark) {
mark->m.mnt = mnt;
mark->m.mnt = mnt;
/* is mark the first mark? */
if (hlist_empty(&mnt->mnt_fsnotify_marks)) {
hlist_add_head(&mark->m.m_list, &mnt->mnt_fsnotify_marks);
goto out;
}
/* should mark be in the middle of the current list? */
hlist_for_each_entry(lmark, node, &mnt->mnt_fsnotify_marks, m.m_list) {
last = node;
if ((lmark->group == group) && !allow_dups) {
ret = -EEXIST;
goto out;
}
if (mark->group < lmark->group)
continue;
fsnotify_recalc_vfsmount_mask_locked(mnt);
} else {
ret = -EEXIST;
hlist_add_before(&mark->m.m_list, &lmark->m.m_list);
goto out;
}
BUG_ON(last == NULL);
/* mark should be the last entry. last is the current last entry */
hlist_add_after(last, &mark->m.m_list);
out:
fsnotify_recalc_vfsmount_mask_locked(mnt);
spin_unlock(&mnt->mnt_root->d_lock);
return ret;
......
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