From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f68.google.com ([209.85.213.68]:34500 "EHLO mail-vk0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752792AbdDDUi5 (ORCPT ); Tue, 4 Apr 2017 16:38:57 -0400 Received: by mail-vk0-f68.google.com with SMTP id y16so24591908vky.1 for ; Tue, 04 Apr 2017 13:38:57 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20170403153424.24945-5-jack@suse.cz> References: <20170403153424.24945-1-jack@suse.cz> <20170403153424.24945-5-jack@suse.cz> From: Paul Moore Date: Tue, 4 Apr 2017 16:38:55 -0400 Message-ID: Subject: Re: [PATCH 04/35] audit: Abstract hash key handling To: Jan Kara Cc: linux-fsdevel@vger.kernel.org, Miklos Szeredi , Amir Goldstein Content-Type: text/plain; charset=UTF-8 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, Apr 3, 2017 at 11:33 AM, Jan Kara wrote: > Audit tree currently uses inode pointer as a key into the hash table. > Getting that from notification mark will be somewhat more difficult with > coming fsnotify changes. So abstract getting of hash key from the audit > chunk and inode so that we can change the method to obtain a key easily. > > Reviewed-by: Miklos Szeredi > CC: Paul Moore > Signed-off-by: Jan Kara > --- > kernel/audit_tree.c | 39 ++++++++++++++++++++++++++++----------- > 1 file changed, 28 insertions(+), 11 deletions(-) Thanks Jan. Acked-by: Paul Moore > diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c > index 7b44195da81b..11c7ac441624 100644 > --- a/kernel/audit_tree.c > +++ b/kernel/audit_tree.c > @@ -163,33 +163,48 @@ enum {HASH_SIZE = 128}; > static struct list_head chunk_hash_heads[HASH_SIZE]; > static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); > > -static inline struct list_head *chunk_hash(const struct inode *inode) > +/* Function to return search key in our hash from inode. */ > +static unsigned long inode_to_key(const struct inode *inode) > { > - unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; > + return (unsigned long)inode; > +} > + > +/* > + * Function to return search key in our hash from chunk. Key 0 is special and > + * should never be present in the hash. > + */ > +static unsigned long chunk_to_key(struct audit_chunk *chunk) > +{ > + return (unsigned long)chunk->mark.inode; > +} > + > +static inline struct list_head *chunk_hash(unsigned long key) > +{ > + unsigned long n = key / L1_CACHE_BYTES; > return chunk_hash_heads + n % HASH_SIZE; > } > > /* hash_lock & entry->lock is held by caller */ > static void insert_hash(struct audit_chunk *chunk) > { > - struct fsnotify_mark *entry = &chunk->mark; > + unsigned long key = chunk_to_key(chunk); > struct list_head *list; > > - if (!entry->inode) > + if (!key) > return; > - list = chunk_hash(entry->inode); > + list = chunk_hash(key); > list_add_rcu(&chunk->hash, list); > } > > /* called under rcu_read_lock */ > struct audit_chunk *audit_tree_lookup(const struct inode *inode) > { > - struct list_head *list = chunk_hash(inode); > + unsigned long key = inode_to_key(inode); > + struct list_head *list = chunk_hash(key); > struct audit_chunk *p; > > list_for_each_entry_rcu(p, list, hash) { > - /* mark.inode may have gone NULL, but who cares? */ > - if (p->mark.inode == inode) { > + if (chunk_to_key(p) == key) { > atomic_long_inc(&p->refs); > return p; > } > @@ -588,7 +603,8 @@ int audit_remove_tree_rule(struct audit_krule *rule) > > static int compare_root(struct vfsmount *mnt, void *arg) > { > - return d_backing_inode(mnt->mnt_root) == arg; > + return inode_to_key(d_backing_inode(mnt->mnt_root)) == > + (unsigned long)arg; > } > > void audit_trim_trees(void) > @@ -623,9 +639,10 @@ void audit_trim_trees(void) > list_for_each_entry(node, &tree->chunks, list) { > struct audit_chunk *chunk = find_chunk(node); > /* this could be NULL if the watch is dying else where... */ > - struct inode *inode = chunk->mark.inode; > node->index |= 1U<<31; > - if (iterate_mounts(compare_root, inode, root_mnt)) > + if (iterate_mounts(compare_root, > + (void *)chunk_to_key(chunk), > + root_mnt)) > node->index &= ~(1U<<31); > } > spin_unlock(&hash_lock); > -- > 2.10.2 > -- paul moore www.paul-moore.com