destroy_list is used to track marks which still need waiting for srcu
period end before they can be freed. However by the time mark is added
to destroy_list it isn't in group's list of marks anymore and thus we
can reuse fsnotify_mark->g_list for queueing into destroy_list. This
saves two pointers for each fsnotify_mark.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/notify/mark.c | 8 ++++----
include/linux/fsnotify_backend.h | 7 +++++--
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index d429b120eab8..396a0545feb1 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -161,7 +161,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
mutex_unlock(&group->mark_mutex);
spin_lock(&destroy_lock);
- list_add(&mark->destroy_list, &destroy_list);
+ list_add(&mark->g_list, &destroy_list);
spin_unlock(&destroy_lock);
wake_up(&destroy_waitq);
/*
@@ -370,7 +370,7 @@ err:
spin_unlock(&mark->lock);
spin_lock(&destroy_lock);
- list_add(&mark->destroy_list, &destroy_list);
+ list_add(&mark->g_list, &destroy_list);
spin_unlock(&destroy_lock);
wake_up(&destroy_waitq);
@@ -469,8 +469,8 @@ static int fsnotify_mark_destroy(void *ignored)
synchronize_srcu(&fsnotify_mark_srcu);
- list_for_each_entry_safe(mark, next, &private_destroy_list, destroy_list) {
- list_del_init(&mark->destroy_list);
+ list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) {
+ list_del_init(&mark->g_list);
fsnotify_put_mark(mark);
}
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 442847a02b8f..0f313f93c586 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -212,7 +212,11 @@ struct fsnotify_mark {
* in kernel that found and may be using this mark. */
atomic_t refcnt; /* active things looking at this mark */
struct fsnotify_group *group; /* group this mark is for */
- struct list_head g_list; /* list of marks by group->i_fsnotify_marks */
+ struct list_head g_list; /* list of marks by group->i_fsnotify_marks
+ * Also reused for queueing mark into
+ * destroy_list when it's waiting for
+ * the end of SRCU period before it can
+ * be freed */
spinlock_t lock; /* protect group and inode */
struct hlist_node obj_list; /* list of marks for inode / vfsmount */
struct list_head free_list; /* tmp list used when freeing this mark */
@@ -227,7 +231,6 @@ struct fsnotify_mark {
#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x08
#define FSNOTIFY_MARK_FLAG_ALIVE 0x10
unsigned int flags; /* vfsmount or inode mark? */
- struct list_head destroy_list;
void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */
};
--
1.8.1.4
--
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