fsnotify: use type id to identify connector object type

An fsnotify_mark_connector is referencing a single type of object
(either inode or vfsmount). Instead of storing a type mask in
connector->flags, store a single type id in connector->type to
identify the type of object.

When a connector object is detached from the object, its type is set
to FSNOTIFY_OBJ_TYPE_DETACHED and this object is not going to be
reused.

The function fsnotify_clear_marks_by_group() is the only place where
type mask was used, so use type flags instead of type id to this
function.

This change is going to be more convenient when adding a new object
type (super block).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index d478629c728beabe160468903fe59ca7500c2f77..10aac1942c9f32e537c9b102429c10340daaa323 100644 (file)
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -77,7 +77,7 @@ static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
        struct inotify_inode_mark *inode_mark;
        struct inode *inode;
 
-       if (!(mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE))
+       if (mark->connector->type != FSNOTIFY_OBJ_TYPE_INODE)
                return;
 
        inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
@@ -116,7 +116,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
        if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
                mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
 
-       if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE) {
+       if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
                inode = igrab(mark->connector->inode);
                if (!inode)
                        return;
@@ -126,7 +126,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
                show_mark_fhandle(m, inode);
                seq_putc(m, '\n');
                iput(inode);
-       } else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
+       } else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
                struct mount *mnt = real_mount(mark->connector->mnt);
 
                seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",

diff --git a/fs/notify/group.c b/fs/notify/group.c
index b7a4b6a69efa97f5c698ee1c93cb0b3992d80e49..aa5468f23e45ceea0b524019d2c0968b72c02eea 100644 (file)
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -67,7 +67,7 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
        fsnotify_group_stop_queueing(group);
 
        /* Clear all marks for this group and queue them for destruction */
-       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_ALL_TYPES);
+       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_ALL_TYPES_MASK);
 
        /*
         * Some marks can still be pinned when waiting for response from

diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index e9191b416434e68d7794bb5dcf8784c1a402f144..ef44808b28ca347233d482c0b778526bd2b9901e 100644 (file)
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -119,9 +119,9 @@ static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
                if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)
                        new_mask |= mark->mask;
        }
-       if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE)
+       if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
                conn->inode->i_fsnotify_mask = new_mask;
-       else if (conn->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)
+       else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
                real_mount(conn->mnt)->mnt_fsnotify_mask = new_mask;
 }
 
@@ -139,7 +139,7 @@ void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
        spin_lock(&conn->lock);
        __fsnotify_recalc_mask(conn);
        spin_unlock(&conn->lock);
-       if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE)
+       if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
                __fsnotify_update_child_dentry_flags(conn->inode);
 }
 
@@ -166,18 +166,18 @@ static struct inode *fsnotify_detach_connector_from_object(
 {
        struct inode *inode = NULL;
 
-       if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE) {
+       if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
                inode = conn->inode;
                rcu_assign_pointer(inode->i_fsnotify_marks, NULL);
                inode->i_fsnotify_mask = 0;
                conn->inode = NULL;
-               conn->flags &= ~FSNOTIFY_OBJ_TYPE_INODE;
-       } else if (conn->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
+               conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
+       } else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
                rcu_assign_pointer(real_mount(conn->mnt)->mnt_fsnotify_marks,
                                   NULL);
                real_mount(conn->mnt)->mnt_fsnotify_mask = 0;
                conn->mnt = NULL;
-               conn->flags &= ~FSNOTIFY_OBJ_TYPE_VFSMOUNT;
+               conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
        }
 
        return inode;
@@ -442,10 +442,10 @@ static int fsnotify_attach_connector_to_object(
        spin_lock_init(&conn->lock);
        INIT_HLIST_HEAD(&conn->list);
        if (inode) {
-               conn->flags = FSNOTIFY_OBJ_TYPE_INODE;
+               conn->type = FSNOTIFY_OBJ_TYPE_INODE;
                conn->inode = igrab(inode);
        } else {
-               conn->flags = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
+               conn->type = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
                conn->mnt = mnt;
        }
        /*
@@ -479,8 +479,7 @@ static struct fsnotify_mark_connector *fsnotify_grab_connector(
        if (!conn)
                goto out;
        spin_lock(&conn->lock);
-       if (!(conn->flags & (FSNOTIFY_OBJ_TYPE_INODE |
-                            FSNOTIFY_OBJ_TYPE_VFSMOUNT))) {
+       if (conn->type == FSNOTIFY_OBJ_TYPE_DETACHED) {
                spin_unlock(&conn->lock);
                srcu_read_unlock(&fsnotify_mark_srcu, idx);
                return NULL;
@@ -646,16 +645,16 @@ struct fsnotify_mark *fsnotify_find_mark(
        return NULL;
 }
 
-/* Clear any marks in a group with given type */
+/* Clear any marks in a group with given type mask */
 void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
-                                  unsigned int type)
+                                  unsigned int type_mask)
 {
        struct fsnotify_mark *lmark, *mark;
        LIST_HEAD(to_free);
        struct list_head *head = &to_free;
 
        /* Skip selection step if we want to clear all marks. */
-       if (type == FSNOTIFY_OBJ_ALL_TYPES) {
+       if (type_mask == FSNOTIFY_OBJ_ALL_TYPES_MASK) {
                head = &group->marks_list;
                goto clear;
        }
@@ -670,7 +669,7 @@ void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
         */
        mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
        list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) {
-               if (mark->connector->flags & type)
+               if ((1U << mark->connector->type) & type_mask)
                        list_move(&mark->g_list, &to_free);
        }
        mutex_unlock(&group->mark_mutex);

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index e64c0294f50bf82dd50d447e37a5c77f86eabc26..435c94a31c8c834899539d2c3b3695873fa892d3 100644 (file)
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -201,6 +201,17 @@ struct fsnotify_group {
 #define FSNOTIFY_EVENT_PATH    1
 #define FSNOTIFY_EVENT_INODE   2
 
+enum fsnotify_obj_type {
+       FSNOTIFY_OBJ_TYPE_INODE,
+       FSNOTIFY_OBJ_TYPE_VFSMOUNT,
+       FSNOTIFY_OBJ_TYPE_COUNT,
+       FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT
+};
+
+#define FSNOTIFY_OBJ_TYPE_INODE_FL     (1U << FSNOTIFY_OBJ_TYPE_INODE)
+#define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL  (1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT)
+#define FSNOTIFY_OBJ_ALL_TYPES_MASK    ((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1)
+
 /*
  * Inode / vfsmount point to this structure which tracks all marks attached to
  * the inode / vfsmount. The reference to inode / vfsmount is held by this
@@ -209,11 +220,7 @@ struct fsnotify_group {
  */
 struct fsnotify_mark_connector {
        spinlock_t lock;
-#define FSNOTIFY_OBJ_TYPE_INODE                0x01
-#define FSNOTIFY_OBJ_TYPE_VFSMOUNT     0x02
-#define FSNOTIFY_OBJ_ALL_TYPES         (FSNOTIFY_OBJ_TYPE_INODE | \
-                                        FSNOTIFY_OBJ_TYPE_VFSMOUNT)
-       unsigned int flags;     /* Type of object [lock] */
+       unsigned int type;      /* Type of object [lock] */
        union { /* Object pointer [lock] */
                struct inode *inode;
                struct vfsmount *mnt;
@@ -369,12 +376,12 @@ extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned
 /* run all the marks in a group, and clear all of the vfsmount marks */
 static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
 {
-       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT);
+       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL);
 }
 /* run all the marks in a group, and clear all of the inode marks */
 static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
 {
-       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE);
+       fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL);
 }
 extern void fsnotify_get_mark(struct fsnotify_mark *mark);
 extern void fsnotify_put_mark(struct fsnotify_mark *mark);