xfs: remove nr_to_write writeback windup.
[safe/jmp/linux-2.6] / kernel / audit_tree.c
index 8b50944..46a57b5 100644 (file)
@@ -2,6 +2,8 @@
 #include <linux/inotify.h>
 #include <linux/namei.h>
 #include <linux/mount.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
 
 struct audit_tree;
 struct audit_chunk;
@@ -276,7 +278,7 @@ static void untag_chunk(struct node *p)
                owner->root = NULL;
        }
 
-       for (i = j = 0; i < size; i++, j++) {
+       for (i = j = 0; j <= size; i++, j++) {
                struct audit_tree *s;
                if (&chunk->owners[j] == p) {
                        list_del_init(&p->list);
@@ -289,7 +291,7 @@ static void untag_chunk(struct node *p)
                if (!s) /* result of earlier fallback */
                        continue;
                get_tree(s);
-               list_replace_init(&chunk->owners[i].list, &new->owners[j].list);
+               list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
        }
 
        list_replace_rcu(&chunk->hash, &new->hash);
@@ -372,19 +374,22 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
        for (n = 0; n < old->count; n++) {
                if (old->owners[n].owner == tree) {
                        spin_unlock(&hash_lock);
-                       put_inotify_watch(watch);
+                       put_inotify_watch(&old->watch);
                        return 0;
                }
        }
        spin_unlock(&hash_lock);
 
        chunk = alloc_chunk(old->count + 1);
-       if (!chunk)
+       if (!chunk) {
+               put_inotify_watch(&old->watch);
                return -ENOMEM;
+       }
 
        mutex_lock(&inode->inotify_mutex);
        if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) {
                mutex_unlock(&inode->inotify_mutex);
+               put_inotify_watch(&old->watch);
                free_chunk(chunk);
                return -ENOSPC;
        }
@@ -394,6 +399,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
                chunk->dead = 1;
                inotify_evict_watch(&chunk->watch);
                mutex_unlock(&inode->inotify_mutex);
+               put_inotify_watch(&old->watch);
                put_inotify_watch(&chunk->watch);
                return 0;
        }
@@ -422,7 +428,8 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
        spin_unlock(&hash_lock);
        inotify_evict_watch(&old->watch);
        mutex_unlock(&inode->inotify_mutex);
-       put_inotify_watch(&old->watch);
+       put_inotify_watch(&old->watch); /* pair to inotify_find_watch */
+       put_inotify_watch(&old->watch); /* and kill it */
        return 0;
 }
 
@@ -439,17 +446,16 @@ static void kill_rules(struct audit_tree *tree)
                if (rule->tree) {
                        /* not a half-baked one */
                        ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
-                       audit_log_format(ab, "op=remove rule dir=");
+                       audit_log_format(ab, "op=");
+                       audit_log_string(ab, "remove rule");
+                       audit_log_format(ab, " dir=");
                        audit_log_untrustedstring(ab, rule->tree->pathname);
-                       if (rule->filterkey) {
-                               audit_log_format(ab, " key=");
-                               audit_log_untrustedstring(ab, rule->filterkey);
-                       } else
-                               audit_log_format(ab, " key=(null)");
+                       audit_log_key(ab, rule->filterkey);
                        audit_log_format(ab, " list=%d res=1", rule->listnr);
                        audit_log_end(ab);
                        rule->tree = NULL;
                        list_del_rcu(&entry->list);
+                       list_del(&entry->rule.list);
                        call_rcu(&entry->rcu, audit_free_rule_rcu);
                }
        }
@@ -516,6 +522,8 @@ static void trim_marked(struct audit_tree *tree)
        }
 }
 
+static void audit_schedule_prune(void);
+
 /* called with audit_filter_mutex */
 int audit_remove_tree_rule(struct audit_krule *rule)
 {
@@ -541,6 +549,11 @@ int audit_remove_tree_rule(struct audit_krule *rule)
        return 0;
 }
 
+static int compare_root(struct vfsmount *mnt, void *arg)
+{
+       return mnt->mnt_root->d_inode == arg;
+}
+
 void audit_trim_trees(void)
 {
        struct list_head cursor;
@@ -552,7 +565,6 @@ void audit_trim_trees(void)
                struct path path;
                struct vfsmount *root_mnt;
                struct node *node;
-               struct list_head list;
                int err;
 
                tree = container_of(cursor.next, struct audit_tree, list);
@@ -565,29 +577,21 @@ void audit_trim_trees(void)
                if (err)
                        goto skip_it;
 
-               root_mnt = collect_mounts(path.mnt, path.dentry);
+               root_mnt = collect_mounts(&path);
                path_put(&path);
                if (!root_mnt)
                        goto skip_it;
 
-               list_add_tail(&list, &root_mnt->mnt_list);
                spin_lock(&hash_lock);
                list_for_each_entry(node, &tree->chunks, list) {
-                       struct audit_chunk *chunk = find_chunk(node);
-                       struct inode *inode = chunk->watch.inode;
-                       struct vfsmount *mnt;
+                       struct inode *inode = find_chunk(node)->watch.inode;
                        node->index |= 1U<<31;
-                       list_for_each_entry(mnt, &list, mnt_list) {
-                               if (mnt->mnt_root->d_inode == inode) {
-                                       node->index &= ~(1U<<31);
-                                       break;
-                               }
-                       }
+                       if (iterate_mounts(compare_root, inode, root_mnt))
+                               node->index &= ~(1U<<31);
                }
                spin_unlock(&hash_lock);
                trim_marked(tree);
                put_tree(tree);
-               list_del_init(&list);
                drop_collected_mounts(root_mnt);
 skip_it:
                mutex_lock(&audit_filter_mutex);
@@ -596,28 +600,12 @@ skip_it:
        mutex_unlock(&audit_filter_mutex);
 }
 
-static int is_under(struct vfsmount *mnt, struct dentry *dentry,
-                   struct path *path)
-{
-       if (mnt != path->mnt) {
-               for (;;) {
-                       if (mnt->mnt_parent == mnt)
-                               return 0;
-                       if (mnt->mnt_parent == path->mnt)
-                                       break;
-                       mnt = mnt->mnt_parent;
-               }
-               dentry = mnt->mnt_mountpoint;
-       }
-       return is_subdir(dentry, path->dentry);
-}
-
 int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
 {
 
        if (pathname[0] != '/' ||
            rule->listnr != AUDIT_FILTER_EXIT ||
-           op & ~AUDIT_EQUAL ||
+           op != Audit_equal ||
            rule->inode_f || rule->watch || rule->tree)
                return -EINVAL;
        rule->tree = alloc_tree(pathname);
@@ -631,13 +619,17 @@ void audit_put_tree(struct audit_tree *tree)
        put_tree(tree);
 }
 
+static int tag_mount(struct vfsmount *mnt, void *arg)
+{
+       return tag_chunk(mnt->mnt_root->d_inode, arg);
+}
+
 /* called with audit_filter_mutex */
 int audit_add_tree_rule(struct audit_krule *rule)
 {
        struct audit_tree *seed = rule->tree, *tree;
        struct path path;
-       struct vfsmount *mnt, *p;
-       struct list_head list;
+       struct vfsmount *mnt;
        int err;
 
        list_for_each_entry(tree, &tree_list, list) {
@@ -657,22 +649,15 @@ int audit_add_tree_rule(struct audit_krule *rule)
        err = kern_path(tree->pathname, 0, &path);
        if (err)
                goto Err;
-       mnt = collect_mounts(path.mnt, path.dentry);
+       mnt = collect_mounts(&path);
        path_put(&path);
        if (!mnt) {
                err = -ENOMEM;
                goto Err;
        }
-       list_add_tail(&list, &mnt->mnt_list);
 
        get_tree(tree);
-       list_for_each_entry(p, &list, mnt_list) {
-               err = tag_chunk(p->mnt_root->d_inode, tree);
-               if (err)
-                       break;
-       }
-
-       list_del(&list);
+       err = iterate_mounts(tag_mount, tree, mnt);
        drop_collected_mounts(mnt);
 
        if (!err) {
@@ -707,34 +692,23 @@ int audit_tag_tree(char *old, char *new)
 {
        struct list_head cursor, barrier;
        int failed = 0;
-       struct path path;
+       struct path path1, path2;
        struct vfsmount *tagged;
-       struct list_head list;
-       struct vfsmount *mnt;
-       struct dentry *dentry;
        int err;
 
-       err = kern_path(new, 0, &path);
+       err = kern_path(new, 0, &path2);
        if (err)
                return err;
-       tagged = collect_mounts(path.mnt, path.dentry);
-       path_put(&path);
+       tagged = collect_mounts(&path2);
+       path_put(&path2);
        if (!tagged)
                return -ENOMEM;
 
-       err = kern_path(old, 0, &path);
+       err = kern_path(old, 0, &path1);
        if (err) {
                drop_collected_mounts(tagged);
                return err;
        }
-       mnt = mntget(path.mnt);
-       dentry = dget(path.dentry);
-       path_put(&path);
-
-       if (dentry == tagged->mnt_root && dentry == mnt->mnt_root)
-               follow_up(&mnt, &dentry);
-
-       list_add_tail(&list, &tagged->mnt_list);
 
        mutex_lock(&audit_filter_mutex);
        list_add(&barrier, &tree_list);
@@ -742,7 +716,7 @@ int audit_tag_tree(char *old, char *new)
 
        while (cursor.next != &tree_list) {
                struct audit_tree *tree;
-               struct vfsmount *p;
+               int good_one = 0;
 
                tree = container_of(cursor.next, struct audit_tree, list);
                get_tree(tree);
@@ -750,30 +724,19 @@ int audit_tag_tree(char *old, char *new)
                list_add(&cursor, &tree->list);
                mutex_unlock(&audit_filter_mutex);
 
-               err = kern_path(tree->pathname, 0, &path);
-               if (err) {
-                       put_tree(tree);
-                       mutex_lock(&audit_filter_mutex);
-                       continue;
+               err = kern_path(tree->pathname, 0, &path2);
+               if (!err) {
+                       good_one = path_is_under(&path1, &path2);
+                       path_put(&path2);
                }
 
-               spin_lock(&vfsmount_lock);
-               if (!is_under(mnt, dentry, &path)) {
-                       spin_unlock(&vfsmount_lock);
-                       path_put(&path);
+               if (!good_one) {
                        put_tree(tree);
                        mutex_lock(&audit_filter_mutex);
                        continue;
                }
-               spin_unlock(&vfsmount_lock);
-               path_put(&path);
-
-               list_for_each_entry(p, &list, mnt_list) {
-                       failed = tag_chunk(p->mnt_root->d_inode, tree);
-                       if (failed)
-                               break;
-               }
 
+               failed = iterate_mounts(tag_mount, tree, tagged);
                if (failed) {
                        put_tree(tree);
                        mutex_lock(&audit_filter_mutex);
@@ -814,20 +777,19 @@ int audit_tag_tree(char *old, char *new)
        }
        list_del(&barrier);
        list_del(&cursor);
-       list_del(&list);
        mutex_unlock(&audit_filter_mutex);
-       dput(dentry);
-       mntput(mnt);
+       path_put(&path1);
        drop_collected_mounts(tagged);
        return failed;
 }
 
 /*
  * That gets run when evict_chunk() ends up needing to kill audit_tree.
- * Runs from a separate thread, with audit_cmd_mutex held.
+ * Runs from a separate thread.
  */
-void audit_prune_trees(void)
+static int prune_tree_thread(void *unused)
 {
+       mutex_lock(&audit_cmd_mutex);
        mutex_lock(&audit_filter_mutex);
 
        while (!list_empty(&prune_list)) {
@@ -844,6 +806,40 @@ void audit_prune_trees(void)
        }
 
        mutex_unlock(&audit_filter_mutex);
+       mutex_unlock(&audit_cmd_mutex);
+       return 0;
+}
+
+static void audit_schedule_prune(void)
+{
+       kthread_run(prune_tree_thread, NULL, "audit_prune_tree");
+}
+
+/*
+ * ... and that one is done if evict_chunk() decides to delay until the end
+ * of syscall.  Runs synchronously.
+ */
+void audit_kill_trees(struct list_head *list)
+{
+       mutex_lock(&audit_cmd_mutex);
+       mutex_lock(&audit_filter_mutex);
+
+       while (!list_empty(list)) {
+               struct audit_tree *victim;
+
+               victim = list_entry(list->next, struct audit_tree, list);
+               kill_rules(victim);
+               list_del_init(&victim->list);
+
+               mutex_unlock(&audit_filter_mutex);
+
+               prune_one(victim);
+
+               mutex_lock(&audit_filter_mutex);
+       }
+
+       mutex_unlock(&audit_filter_mutex);
+       mutex_unlock(&audit_cmd_mutex);
 }
 
 /*
@@ -854,6 +850,8 @@ void audit_prune_trees(void)
 static void evict_chunk(struct audit_chunk *chunk)
 {
        struct audit_tree *owner;
+       struct list_head *postponed = audit_killed_trees();
+       int need_prune = 0;
        int n;
 
        if (chunk->dead)
@@ -869,15 +867,21 @@ static void evict_chunk(struct audit_chunk *chunk)
                owner->root = NULL;
                list_del_init(&owner->same_root);
                spin_unlock(&hash_lock);
-               kill_rules(owner);
-               list_move(&owner->list, &prune_list);
-               audit_schedule_prune();
+               if (!postponed) {
+                       kill_rules(owner);
+                       list_move(&owner->list, &prune_list);
+                       need_prune = 1;
+               } else {
+                       list_move(&owner->list, postponed);
+               }
                spin_lock(&hash_lock);
        }
        list_del_rcu(&chunk->hash);
        for (n = 0; n < chunk->count; n++)
                list_del_init(&chunk->owners[n].list);
        spin_unlock(&hash_lock);
+       if (need_prune)
+               audit_schedule_prune();
        mutex_unlock(&audit_filter_mutex);
 }