On Wed, Feb 1, 2017 at 12:44 PM, Jan Kara <jack@xxxxxxx> wrote:
> Currently we initialize mark->group only in fsnotify_add_mark_lock().
> However we will need to access fsnotify_ops of corresponding group from
> fsnotify_put_mark() so we need mark->group initialized earlier. Do that
> in fsnotify_init_mark() which has a consequence that once
> fsnotify_init_mark() is called on a mark, the mark has to be destroyed
> by fsnotify_put_mark().
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
>From a quick glance at the audit code, this look ok to me.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/notify/dnotify/dnotify.c | 5 ++---
> fs/notify/fanotify/fanotify_user.c | 4 ++--
> fs/notify/inotify/inotify_user.c | 5 ++---
> fs/notify/mark.c | 17 ++++++++++-------
> include/linux/fsnotify_backend.h | 12 +++++++-----
> kernel/audit_fsnotify.c | 7 ++++---
> kernel/audit_tree.c | 15 ++++++++-------
> kernel/audit_watch.c | 5 +++--
> 8 files changed, 38 insertions(+), 32 deletions(-)
>
> diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
> index b77d8d049e4d..f9d500fd7b9a 100644
> --- a/fs/notify/dnotify/dnotify.c
> +++ b/fs/notify/dnotify/dnotify.c
> @@ -305,7 +305,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
>
> /* set up the new_fsn_mark and new_dn_mark */
> new_fsn_mark = &new_dn_mark->fsn_mark;
> - fsnotify_init_mark(new_fsn_mark, dnotify_free_mark);
> + fsnotify_init_mark(new_fsn_mark, dnotify_group, dnotify_free_mark);
> new_fsn_mark->mask = mask;
> new_dn_mark->dn = NULL;
>
> @@ -318,8 +318,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
> dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark);
> spin_lock(&fsn_mark->lock);
> } else {
> - fsnotify_add_mark_locked(new_fsn_mark, dnotify_group, inode,
> - NULL, 0);
> + fsnotify_add_mark_locked(new_fsn_mark, inode, NULL, 0);
> spin_lock(&new_fsn_mark->lock);
> fsn_mark = new_fsn_mark;
> dn_mark = new_dn_mark;
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index 7b4d9d67f4f9..4ba51b836a44 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -627,8 +627,8 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
> if (!mark)
> return ERR_PTR(-ENOMEM);
>
> - fsnotify_init_mark(mark, fanotify_free_mark);
> - ret = fsnotify_add_mark_locked(mark, group, inode, mnt, 0);
> + fsnotify_init_mark(mark, group, fanotify_free_mark);
> + ret = fsnotify_add_mark_locked(mark, inode, mnt, 0);
> if (ret) {
> fsnotify_put_mark(mark);
> return ERR_PTR(ret);
> diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
> index 546a4c7d0f03..38e66d497b3b 100644
> --- a/fs/notify/inotify/inotify_user.c
> +++ b/fs/notify/inotify/inotify_user.c
> @@ -561,7 +561,7 @@ static int inotify_new_watch(struct fsnotify_group *group,
> if (unlikely(!tmp_i_mark))
> return -ENOMEM;
>
> - fsnotify_init_mark(&tmp_i_mark->fsn_mark, inotify_free_mark);
> + fsnotify_init_mark(&tmp_i_mark->fsn_mark, group, inotify_free_mark);
> tmp_i_mark->fsn_mark.mask = mask;
> tmp_i_mark->wd = -1;
>
> @@ -574,8 +574,7 @@ static int inotify_new_watch(struct fsnotify_group *group,
> goto out_err;
>
> /* we are on the idr, now get on the inode */
> - ret = fsnotify_add_mark_locked(&tmp_i_mark->fsn_mark, group, inode,
> - NULL, 0);
> + ret = fsnotify_add_mark_locked(&tmp_i_mark->fsn_mark, inode, NULL, 0);
> if (ret) {
> /* we failed to get on the inode, get off the idr */
> inotify_remove_from_idr(group, tmp_i_mark);
> diff --git a/fs/notify/mark.c b/fs/notify/mark.c
> index 4f9df2021db5..d45dfc7207ce 100644
> --- a/fs/notify/mark.c
> +++ b/fs/notify/mark.c
> @@ -546,10 +546,10 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
> * These marks may be used for the fsnotify backend to determine which
> * event types should be delivered to which group.
> */
> -int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
> - struct fsnotify_group *group, struct inode *inode,
> +int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct inode *inode,
> struct vfsmount *mnt, int allow_dups)
> {
> + struct fsnotify_group *group = mark->group;
> int ret = 0;
>
> BUG_ON(inode && mnt);
> @@ -565,8 +565,6 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
> spin_lock(&mark->lock);
> mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_ATTACHED;
>
> - fsnotify_get_group(group);
> - mark->group = group;
> list_add(&mark->g_list, &group->marks_list);
> atomic_inc(&group->num_marks);
> fsnotify_get_mark(mark); /* for g_list */
> @@ -591,12 +589,14 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
> return ret;
> }
>
> -int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,
> - struct inode *inode, struct vfsmount *mnt, int allow_dups)
> +int fsnotify_add_mark(struct fsnotify_mark *mark, struct inode *inode,
> + struct vfsmount *mnt, int allow_dups)
> {
> int ret;
> + struct fsnotify_group *group = mark->group;
> +
> mutex_lock(&group->mark_mutex);
> - ret = fsnotify_add_mark_locked(mark, group, inode, mnt, allow_dups);
> + ret = fsnotify_add_mark_locked(mark, inode, mnt, allow_dups);
> mutex_unlock(&group->mark_mutex);
> return ret;
> }
> @@ -714,12 +714,15 @@ void fsnotify_destroy_marks(struct fsnotify_mark_connector **connp)
> * Nothing fancy, just initialize lists and locks and counters.
> */
> void fsnotify_init_mark(struct fsnotify_mark *mark,
> + struct fsnotify_group *group,
> void (*free_mark)(struct fsnotify_mark *mark))
> {
> memset(mark, 0, sizeof(*mark));
> spin_lock_init(&mark->lock);
> atomic_set(&mark->refcnt, 1);
> mark->free_mark = free_mark;
> + fsnotify_get_group(group);
> + mark->group = group;
> }
>
> /*
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index d30af83eb4d9..2aad469648b5 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -339,15 +339,17 @@ extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group
>
> /* Calculate mask of events for a list of marks */
> extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
> -extern void fsnotify_init_mark(struct fsnotify_mark *mark, void (*free_mark)(struct fsnotify_mark *mark));
> +extern void fsnotify_init_mark(struct fsnotify_mark *mark,
> + struct fsnotify_group *group,
> + void (*free_mark)(struct fsnotify_mark *mark));
> /* Find mark belonging to given group in the list of marks */
> extern struct fsnotify_mark *fsnotify_find_mark(
> struct fsnotify_mark_connector **connp,
> struct fsnotify_group *group);
> -/* attach the mark to both the group and the inode */
> -extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,
> - struct inode *inode, struct vfsmount *mnt, int allow_dups);
> -extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct fsnotify_group *group,
> +/* attach the mark to the inode or vfsmount */
> +extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct inode *inode,
> + struct vfsmount *mnt, int allow_dups);
> +extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
> struct inode *inode, struct vfsmount *mnt, int allow_dups);
> /* given a group and a mark, flag mark to be freed when all references are dropped */
> extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,
> diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
> index e8b371ff1e91..2522ceaca758 100644
> --- a/kernel/audit_fsnotify.c
> +++ b/kernel/audit_fsnotify.c
> @@ -103,15 +103,16 @@ struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pa
> goto out;
> }
>
> - fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_free_mark);
> + fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_group,
> + audit_fsnotify_free_mark);
> audit_mark->mark.mask = AUDIT_FS_EVENTS;
> audit_mark->path = pathname;
> audit_update_mark(audit_mark, dentry->d_inode);
> audit_mark->rule = krule;
>
> - ret = fsnotify_add_mark(&audit_mark->mark, audit_fsnotify_group, inode, NULL, true);
> + ret = fsnotify_add_mark(&audit_mark->mark, inode, NULL, true);
> if (ret < 0) {
> - audit_fsnotify_mark_free(audit_mark);
> + fsnotify_put_mark(&audit_mark->mark);
> audit_mark = ERR_PTR(ret);
> }
> out:
> diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
> index c90efa2aa672..36a43efc8597 100644
> --- a/kernel/audit_tree.c
> +++ b/kernel/audit_tree.c
> @@ -154,7 +154,8 @@ 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_destroy_watch);
> + fsnotify_init_mark(&chunk->mark, audit_tree_group,
> + audit_tree_destroy_watch);
> chunk->mark.mask = FS_IN_IGNORED;
> return chunk;
> }
> @@ -256,7 +257,7 @@ static void untag_chunk(struct node *p)
> spin_unlock(&entry->lock);
> mutex_unlock(&entry->group->mark_mutex);
> if (new)
> - free_chunk(new);
> + fsnotify_put_mark(&new->mark);
> goto out;
> }
>
> @@ -280,8 +281,8 @@ static void untag_chunk(struct node *p)
> if (!new)
> goto Fallback;
>
> - if (fsnotify_add_mark_locked(&new->mark, entry->group,
> - entry->connector->inode, NULL, 1)) {
> + if (fsnotify_add_mark_locked(&new->mark, entry->connector->inode,
> + NULL, 1)) {
> fsnotify_put_mark(&new->mark);
> goto Fallback;
> }
> @@ -346,7 +347,7 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree)
> return -ENOMEM;
>
> entry = &chunk->mark;
> - if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
> + if (fsnotify_add_mark(entry, inode, NULL, 0)) {
> fsnotify_put_mark(entry);
> return -ENOSPC;
> }
> @@ -418,11 +419,11 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
> spin_unlock(&old_entry->lock);
> mutex_unlock(&old_entry->group->mark_mutex);
> fsnotify_put_mark(old_entry);
> - free_chunk(chunk);
> + fsnotify_put_mark(&chunk->mark);
> return -ENOENT;
> }
>
> - if (fsnotify_add_mark_locked(chunk_entry, old_entry->group,
> + if (fsnotify_add_mark_locked(chunk_entry,
> old_entry->connector->inode, NULL, 1)) {
> spin_unlock(&old_entry->lock);
> mutex_unlock(&old_entry->group->mark_mutex);
> diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
> index 956fa584c239..e32efed86828 100644
> --- a/kernel/audit_watch.c
> +++ b/kernel/audit_watch.c
> @@ -157,9 +157,10 @@ static struct audit_parent *audit_init_parent(struct path *path)
>
> INIT_LIST_HEAD(&parent->watches);
>
> - fsnotify_init_mark(&parent->mark, audit_watch_free_mark);
> + fsnotify_init_mark(&parent->mark, audit_watch_group,
> + audit_watch_free_mark);
> parent->mark.mask = AUDIT_FS_WATCH;
> - ret = fsnotify_add_mark(&parent->mark, audit_watch_group, inode, NULL, 0);
> + ret = fsnotify_add_mark(&parent->mark, inode, NULL, 0);
> if (ret < 0) {
> audit_free_parent(parent);
> return ERR_PTR(ret);
> --
> 2.10.2
>
