Currently inode reference is held by fsnotify marks. Change the rules so
that inode reference is held by fsnotify_mark_connector structure
whenever the list is non-empty. This simplifies the code and is more
logical.
Reviewed-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/notify/fsnotify.h | 4 +---
fs/notify/inode_mark.c | 30 +++++-------------------------
fs/notify/mark.c | 17 ++++++-----------
include/linux/fsnotify_backend.h | 12 ++++++------
4 files changed, 18 insertions(+), 45 deletions(-)
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index dd1a6798c9cd..1a2aec65ebd8 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -21,8 +21,6 @@ extern u32 fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
extern int fsnotify_compare_groups(struct fsnotify_group *a,
struct fsnotify_group *b);
-extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,
- __u32 mask);
/* Add mark to a proper place in mark list */
extern int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp,
struct fsnotify_mark *mark,
@@ -40,7 +38,7 @@ extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
/* vfsmount specific destruction of a 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);
+extern struct inode *fsnotify_destroy_inode_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 *conn,
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 1644ba09efd4..c3873b6920e7 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -43,9 +43,10 @@ void fsnotify_recalc_inode_mask(struct inode *inode)
__fsnotify_update_child_dentry_flags(inode);
}
-void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
+struct inode *fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
{
struct inode *inode = mark->connector->inode;
+ bool empty;
BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
assert_spin_locked(&mark->lock);
@@ -53,6 +54,7 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
spin_lock(&inode->i_lock);
hlist_del_init_rcu(&mark->obj_list);
+ empty = hlist_empty(&mark->connector->list);
mark->connector = NULL;
/*
@@ -62,6 +64,8 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
*/
inode->i_fsnotify_mask = fsnotify_recalc_mask(inode->i_fsnotify_marks);
spin_unlock(&inode->i_lock);
+
+ return empty ? inode : NULL;
}
/*
@@ -89,30 +93,6 @@ struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group,
}
/*
- * If we are setting a mark mask on an inode mark we should pin the inode
- * in memory.
- */
-void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
- __u32 mask)
-{
- struct inode *inode;
-
- assert_spin_locked(&mark->lock);
-
- if (mask && mark->connector &&
- !(mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) {
- mark->flags |= FSNOTIFY_MARK_FLAG_OBJECT_PINNED;
- inode = igrab(mark->connector->inode);
- /*
- * we shouldn't be able to get here if the inode wasn't
- * already safely held in memory. But bug in case it
- * ever is wrong.
- */
- BUG_ON(!inode);
- }
-}
-
-/*
* Attach an initialized mark to a given inode.
* These marks may be used for the fsnotify backend to determine which
* event types should be delivered to which group and for which inodes. These
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 3d6e7a8e58be..8a15c64fbe80 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -142,10 +142,9 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark)
mark->flags &= ~FSNOTIFY_MARK_FLAG_ATTACHED;
- if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE) {
- inode = mark->connector->inode;
- fsnotify_destroy_inode_mark(mark);
- } else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)
+ if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE)
+ inode = fsnotify_destroy_inode_mark(mark);
+ else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)
fsnotify_destroy_vfsmount_mark(mark);
else
BUG();
@@ -160,7 +159,7 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark)
spin_unlock(&mark->lock);
- if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED))
+ if (inode)
iput(inode);
atomic_dec(&group->num_marks);
@@ -274,9 +273,6 @@ void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
assert_spin_locked(&mark->lock);
mark->mask = mask;
-
- if (mark->connector && mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE)
- fsnotify_set_inode_mark_mask_locked(mark, mask);
}
void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mask)
@@ -375,6 +371,8 @@ int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp,
/* is mark the first mark? */
if (hlist_empty(&conn->list)) {
hlist_add_head_rcu(&mark->obj_list, &conn->list);
+ if (inode)
+ __iget(inode);
goto added;
}
@@ -441,9 +439,6 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
} else {
BUG();
}
-
- /* this will pin the object if appropriate */
- fsnotify_set_mark_mask_locked(mark, mark->mask);
spin_unlock(&mark->lock);
if (inode)
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 06f9a2cc1463..96333fb09309 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -196,8 +196,9 @@ struct fsnotify_group {
/*
* Inode / vfsmount point to this structure which tracks all marks attached to
- * the inode / vfsmount. The structure is freed only when inode / vfsmount gets
- * freed.
+ * the inode / vfsmount. The reference to inode / vfsmount is held by this
+ * structure whenever the list is non-empty. The structure is freed only when
+ * inode / vfsmount gets freed.
*/
struct fsnotify_mark_connector {
#define FSNOTIFY_OBJ_TYPE_INODE 0x01
@@ -245,10 +246,9 @@ struct fsnotify_mark {
struct fsnotify_mark_connector *connector;
/* Events types to ignore [mark->lock, group->mark_mutex] */
__u32 ignored_mask;
-#define FSNOTIFY_MARK_FLAG_OBJECT_PINNED 0x04
-#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x08
-#define FSNOTIFY_MARK_FLAG_ALIVE 0x10
-#define FSNOTIFY_MARK_FLAG_ATTACHED 0x20
+#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01
+#define FSNOTIFY_MARK_FLAG_ALIVE 0x02
+#define FSNOTIFY_MARK_FLAG_ATTACHED 0x04
unsigned int flags; /* flags [mark->lock] */
void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */
};
--
2.10.2
