Re: [PATCH 11/14] audit: Drop all unused chunk nodes during deletion

When deleting chunk from a tree, drop all unused nodes in a chunk instead of just the one used by the tree. This gets rid of possibly lingering unused nodes (created due to fallback path in untag_chunk()) and also removes some special cases and will allow us to simplify locking in untag_chunk().

Signed-off-by: Jan Kara <jack(a)suse.cz&gt; --- kernel/audit_tree.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index ca2b6baff7aa..145e8c92dd31 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -277,8 +277,7 @@ static struct audit_chunk *find_chunk(struct node *p) return container_of(p, struct audit_chunk, owners[0]); } -static void replace_chunk(struct audit_chunk *new, struct audit_chunk *old, - struct node *skip) +static void replace_chunk(struct audit_chunk *new, struct audit_chunk *old) { struct audit_tree *owner; int i, j; @@ -288,7 +287,7 @@ static void replace_chunk(struct audit_chunk *new, struct audit_chunk *old, list_for_each_entry(owner, &new->trees, same_root) owner->root = new; for (i = j = 0; j < old->count; i++, j++) { - if (&old->owners[j] == skip) { + if (!old->owners[j].owner) { i--; continue; } @@ -322,20 +321,28 @@ static void remove_chunk_node(struct audit_chunk *chunk, struct node *p) put_tree(owner); } +static int chunk_count_trees(struct audit_chunk *chunk) +{ + int i; + int ret = 0; + + for (i = 0; i < chunk->count; i++) + if (chunk->owners[i].owner) + ret++; + return ret; +} + static void untag_chunk(struct node *p) { struct audit_chunk *chunk = find_chunk(p); struct fsnotify_mark *entry = chunk->mark; struct audit_chunk *new = NULL; - int size = chunk->count - 1; + int size; remove_chunk_node(chunk, p); fsnotify_get_mark(entry); spin_unlock(&hash_lock); - if (size) - new = alloc_chunk(size); - mutex_lock(&entry->group->mark_mutex); /* * mark_mutex protects mark from getting detached and thus also from @@ -348,6 +355,7 @@ static void untag_chunk(struct node *p) goto out; } + size = chunk_count_trees(chunk); if (!size) { chunk->dead = 1; spin_lock(&hash_lock); @@ -360,6 +368,7 @@ static void untag_chunk(struct node *p) goto out; } + new = alloc_chunk(size); if (!new) goto out_mutex; @@ -375,7 +384,7 @@ static void untag_chunk(struct node *p) * This has to go last when updating chunk as once replace_chunk() is * called, new RCU readers can see the new chunk. */ - replace_chunk(new, chunk, p); + replace_chunk(new, chunk); spin_unlock(&hash_lock); fsnotify_detach_mark(entry); mutex_unlock(&entry->group->mark_mutex); @@ -520,7 +529,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree) * This has to go last when updating chunk as once replace_chunk() is * called, new RCU readers can see the new chunk. */ - replace_chunk(chunk, old, NULL); + replace_chunk(chunk, old); spin_unlock(&hash_lock); fsnotify_detach_mark(old_entry); mutex_unlock(&audit_tree_group->mark_mutex); -- 2.16.4