[PATCH 09/14] audit: Allocate fsnotify mark independently of chunk

Allocate fsnotify mark independently instead of embedding it inside chunk. This will allow us to just replace chunk attached to mark when growing / shrinking chunk instead of replacing mark attached to inode which is a more complex operation. Reviewed-by: Richard Guy Briggs <rgb(a)redhat.com&gt; Signed-off-by: Jan Kara <jack(a)suse.cz&gt; --- kernel/audit_tree.c | 64 +++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 50 insertions(+), 14 deletions(-) diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 35c031ebcc12..c98ab2d68a1c 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -25,7 +25,7 @@ struct audit_tree { struct audit_chunk { struct list_head hash; unsigned long key; - struct fsnotify_mark mark; + struct fsnotify_mark *mark; struct list_head trees; /* with root here */ int dead; int count; @@ -38,6 +38,11 @@ struct audit_chunk { } owners[]; }; +struct audit_tree_mark { + struct fsnotify_mark mark; + struct audit_chunk *chunk; +}; + static LIST_HEAD(tree_list); static LIST_HEAD(prune_list); static struct task_struct *prune_thread; @@ -73,6 +78,7 @@ static struct task_struct *prune_thread; */ static struct fsnotify_group *audit_tree_group; +static struct kmem_cache *audit_tree_mark_cachep __read_mostly; static struct audit_tree *alloc_tree(const char *s) { @@ -142,10 +148,33 @@ static void audit_mark_put_chunk(struct audit_chunk *chunk) call_rcu(&chunk->head, __put_chunk); } +static inline struct audit_tree_mark *audit_mark(struct fsnotify_mark *entry) +{ + return container_of(entry, struct audit_tree_mark, mark); +} + +static struct audit_chunk *mark_chunk(struct fsnotify_mark *mark) +{ + return audit_mark(mark)->chunk; +} + static void audit_tree_destroy_watch(struct fsnotify_mark *entry) { - struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); + struct audit_chunk *chunk = mark_chunk(entry); audit_mark_put_chunk(chunk); + kmem_cache_free(audit_tree_mark_cachep, audit_mark(entry)); +} + +static struct fsnotify_mark *alloc_mark(void) +{ + struct audit_tree_mark *amark; + + amark = kmem_cache_zalloc(audit_tree_mark_cachep, GFP_KERNEL); + if (!amark) + return NULL; + fsnotify_init_mark(&amark->mark, audit_tree_group); + amark->mark.mask = FS_IN_IGNORED; + return &amark->mark; } static struct audit_chunk *alloc_chunk(int count) @@ -159,6 +188,13 @@ static struct audit_chunk *alloc_chunk(int count) if (!chunk) return NULL; + chunk->mark = alloc_mark(); + if (!chunk->mark) { + kfree(chunk); + return NULL; + } + audit_mark(chunk->mark)->chunk = chunk; + INIT_LIST_HEAD(&chunk->hash); INIT_LIST_HEAD(&chunk->trees); chunk->count = count; @@ -167,8 +203,6 @@ static struct audit_chunk *alloc_chunk(int count) INIT_LIST_HEAD(&chunk->owners[i].list); chunk->owners[i].index = i; } - fsnotify_init_mark(&chunk->mark, audit_tree_group); - chunk->mark.mask = FS_IN_IGNORED; return chunk; } @@ -278,7 +312,7 @@ static void replace_chunk(struct audit_chunk *new, struct audit_chunk *old, static void untag_chunk(struct node *p) { struct audit_chunk *chunk = find_chunk(p); - struct fsnotify_mark *entry = &chunk->mark; + struct fsnotify_mark *entry = chunk->mark; struct audit_chunk *new = NULL; struct audit_tree *owner; int size = chunk->count - 1; @@ -298,7 +332,7 @@ static void untag_chunk(struct node *p) if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { mutex_unlock(&entry->group->mark_mutex); if (new) - fsnotify_put_mark(&new->mark); + fsnotify_put_mark(new->mark); goto out; } @@ -322,9 +356,9 @@ static void untag_chunk(struct node *p) if (!new) goto Fallback; - if (fsnotify_add_mark_locked(&new->mark, entry->connector->obj, + if (fsnotify_add_mark_locked(new->mark, entry->connector->obj, FSNOTIFY_OBJ_TYPE_INODE, 1)) { - fsnotify_put_mark(&new->mark); + fsnotify_put_mark(new->mark); goto Fallback; } @@ -344,7 +378,7 @@ static void untag_chunk(struct node *p) fsnotify_detach_mark(entry); mutex_unlock(&entry->group->mark_mutex); fsnotify_free_mark(entry); - fsnotify_put_mark(&new->mark); /* drop initial reference */ + fsnotify_put_mark(new->mark); /* drop initial reference */ goto out; Fallback: @@ -375,7 +409,7 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree) return -ENOMEM; } - entry = &chunk->mark; + entry = chunk->mark; if (fsnotify_add_inode_mark_locked(entry, inode, 0)) { mutex_unlock(&audit_tree_group->mark_mutex); fsnotify_put_mark(entry); @@ -426,7 +460,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree) if (!old_entry) return create_chunk(inode, tree); - old = container_of(old_entry, struct audit_chunk, mark); + old = mark_chunk(old_entry); /* are we already there? */ spin_lock(&hash_lock); @@ -447,7 +481,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree) return -ENOMEM; } - chunk_entry = &chunk->mark; + chunk_entry = chunk->mark; /* * mark_mutex protects mark from getting detached and thus also from @@ -457,7 +491,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree) /* old_entry is being shot, lets just lie */ mutex_unlock(&audit_tree_group->mark_mutex); fsnotify_put_mark(old_entry); - fsnotify_put_mark(&chunk->mark); + fsnotify_put_mark(chunk->mark); return -ENOENT; } @@ -1011,7 +1045,7 @@ static int audit_tree_handle_event(struct fsnotify_group *group, static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) { - struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); + struct audit_chunk *chunk = mark_chunk(entry); evict_chunk(chunk); @@ -1032,6 +1066,8 @@ static int __init audit_tree_init(void) { int i; + audit_tree_mark_cachep = KMEM_CACHE(audit_tree_mark, SLAB_PANIC); + audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); if (IS_ERR(audit_tree_group)) audit_panic("cannot initialize fsnotify group for rectree watches"); -- 2.16.4