Free list is used when all marks on given inode / mount should be
destroyed when inode / mount is going away. However we can free all of
the marks without using a special list with some care.
Signed-off-by: Jan Kara <jack@xxxxxxxx>
---
fs/notify/fsnotify.c | 1 -
fs/notify/fsnotify.h | 21 +++++++++++++++------
fs/notify/inode_mark.c | 20 --------------------
fs/notify/mark.c | 40 +++++++++++++++++++++++++---------------
fs/notify/vfsmount_mark.c | 19 -------------------
include/linux/fsnotify_backend.h | 2 --
6 files changed, 40 insertions(+), 63 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index dd3fb0b17be7..0771c1ed9525 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -26,7 +26,6 @@
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
-#include "../mount.h"
/*
* Clear all of the marks on an inode when it is being evicted from core
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 13a00be516d2..b44c68a857e7 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -6,6 +6,8 @@
#include <linux/srcu.h>
#include <linux/types.h>
+#include "../mount.h"
+
/* destroy all events sitting in this groups notification queue */
extern void fsnotify_flush_notify(struct fsnotify_group *group);
@@ -38,15 +40,22 @@ extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
extern void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark);
/* inode specific destruction of a mark */
extern void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark);
-/* Destroy all marks in the given list */
-extern void fsnotify_destroy_marks(struct list_head *to_free);
/* Find mark belonging to given group in the list of marks */
extern struct fsnotify_mark *fsnotify_find_mark(struct hlist_head *head,
struct fsnotify_group *group);
-/* run the list of all marks associated with inode and flag them to be freed */
-extern void fsnotify_clear_marks_by_inode(struct inode *inode);
-/* run the list of all marks associated with vfsmount and flag them to be freed */
-extern void fsnotify_clear_marks_by_mount(struct vfsmount *mnt);
+/* Destroy all marks in the given list protected by 'lock' */
+extern void fsnotify_destroy_marks(struct hlist_head *head, spinlock_t *lock);
+/* run the list of all marks associated with inode and destroy them */
+static inline void fsnotify_clear_marks_by_inode(struct inode *inode)
+{
+ fsnotify_destroy_marks(&inode->i_fsnotify_marks, &inode->i_lock);
+}
+/* run the list of all marks associated with vfsmount and destroy them */
+static inline void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
+{
+ fsnotify_destroy_marks(&real_mount(mnt)->mnt_fsnotify_marks,
+ &mnt->mnt_root->d_lock);
+}
/*
* update the dentry->d_flags of all of inode's children to indicate if inode cares
* about events that happen to its children.
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 3daf513ee99e..474a3ce1b5e1 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -65,26 +65,6 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
}
/*
- * Given an inode, destroy all of the marks associated with that inode.
- */
-void fsnotify_clear_marks_by_inode(struct inode *inode)
-{
- struct fsnotify_mark *mark;
- struct hlist_node *n;
- LIST_HEAD(free_list);
-
- spin_lock(&inode->i_lock);
- hlist_for_each_entry_safe(mark, n, &inode->i_fsnotify_marks, obj_list) {
- list_add(&mark->free_list, &free_list);
- hlist_del_init_rcu(&mark->obj_list);
- fsnotify_get_mark(mark);
- }
- spin_unlock(&inode->i_lock);
-
- fsnotify_destroy_marks(&free_list);
-}
-
-/*
* Given a group clear all of the inode marks associated with that group.
*/
void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 39ddcaf0918f..3b2d1ba41e7b 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -203,24 +203,34 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark,
mutex_unlock(&group->mark_mutex);
}
-/*
- * Destroy all marks in the given list. The marks must be already detached from
- * the original inode / vfsmount.
- */
-void fsnotify_destroy_marks(struct list_head *to_free)
+void fsnotify_destroy_marks(struct hlist_head *head, spinlock_t *lock)
{
- struct fsnotify_mark *mark, *lmark;
- struct fsnotify_group *group;
-
- list_for_each_entry_safe(mark, lmark, to_free, free_list) {
- spin_lock(&mark->lock);
- fsnotify_get_group(mark->group);
- group = mark->group;
- spin_unlock(&mark->lock);
+ struct fsnotify_mark *mark;
- fsnotify_destroy_mark(mark, group);
+ while (1) {
+ /*
+ * We have to be careful since we can race with e.g.
+ * fsnotify_clear_marks_by_group() and once we drop 'lock',
+ * mark can get removed from the obj_list and destroyed. But
+ * we are holding mark reference so mark cannot be freed and
+ * calling fsnotify_destroy_mark() more than once is fine.
+ */
+ spin_lock(lock);
+ if (hlist_empty(head)) {
+ spin_unlock(lock);
+ break;
+ }
+ mark = hlist_entry(head->first, struct fsnotify_mark, obj_list);
+ /*
+ * We don't update i_fsnotify_mask / mnt_fsnotify_mask here
+ * since inode / mount is going away anyway. So just remove
+ * mark from the list.
+ */
+ hlist_del_init_rcu(&mark->obj_list);
+ fsnotify_get_mark(mark);
+ spin_unlock(lock);
+ fsnotify_destroy_mark(mark, mark->group);
fsnotify_put_mark(mark);
- fsnotify_put_group(group);
}
}
diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 326b148e623c..a8fcab68faef 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -28,25 +28,6 @@
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
-#include "../mount.h"
-
-void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
-{
- struct fsnotify_mark *mark;
- struct hlist_node *n;
- struct mount *m = real_mount(mnt);
- LIST_HEAD(free_list);
-
- spin_lock(&mnt->mnt_root->d_lock);
- hlist_for_each_entry_safe(mark, n, &m->mnt_fsnotify_marks, obj_list) {
- list_add(&mark->free_list, &free_list);
- hlist_del_init_rcu(&mark->obj_list);
- fsnotify_get_mark(mark);
- }
- spin_unlock(&mnt->mnt_root->d_lock);
-
- fsnotify_destroy_marks(&free_list);
-}
void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
{
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index dd6ddb0287ed..f044fe30e8c3 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -225,8 +225,6 @@ struct fsnotify_mark {
spinlock_t lock;
/* List of marks for inode / vfsmount [obj_lock] */
struct hlist_node obj_list;
- /* tmp list used when freeing this mark */
- struct list_head free_list;
union { /* Object pointer [mark->lock, group->mark_mutex] */
struct inode *inode; /* inode this mark is associated with */
struct vfsmount *mnt; /* vfsmount this mark is associated with */
--
2.1.4
--
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