From 04662cab59fc3e8421fd7a0539d304d51d2750a4 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 1 Feb 2017 08:19:43 +0100 Subject: fsnotify: Lock object list with connector lock So far list of marks attached to an object (inode / vfsmount) was protected by i_lock or mnt_root->d_lock. This dictates that the list must be empty before the object can be destroyed although the list is now anchored in the fsnotify_mark_connector structure. Protect the list by a spinlock in the fsnotify_mark_connector structure to decouple lifetime of a list of marks from a lifetime of the object. This also simplifies the code quite a bit since we don't have to differentiate between inode and vfsmount lists in quite a few places anymore. Reviewed-by: Miklos Szeredi Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara --- include/linux/fsnotify_backend.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/fsnotify_backend.h') diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index b954f1b2571c..02c6fac652a4 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -201,6 +201,7 @@ struct fsnotify_group { * inode / vfsmount gets freed. */ struct fsnotify_mark_connector { + spinlock_t lock; #define FSNOTIFY_OBJ_TYPE_INODE 0x01 #define FSNOTIFY_OBJ_TYPE_VFSMOUNT 0x02 unsigned int flags; /* Type of object [lock] */ @@ -240,7 +241,7 @@ struct fsnotify_mark { struct list_head g_list; /* Protects inode / mnt pointers, flags, masks */ spinlock_t lock; - /* List of marks for inode / vfsmount [obj_lock] */ + /* List of marks for inode / vfsmount [connector->lock] */ struct hlist_node obj_list; /* Head of list of marks for an object [mark->lock, group->mark_mutex] */ struct fsnotify_mark_connector *connector; -- cgit v1.2.3