From 04dd17822334871b23ea2862f7798fb0e0007777 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 11 May 2024 08:53:19 +0000
Subject: [PATCH] change otg to host mode
---
kernel/fs/notify/mark.c | 104 ++++++++++++++++++++++++++++++++++++---------------
1 files changed, 73 insertions(+), 31 deletions(-)
diff --git a/kernel/fs/notify/mark.c b/kernel/fs/notify/mark.c
index 09535f6..5b44be5 100644
--- a/kernel/fs/notify/mark.c
+++ b/kernel/fs/notify/mark.c
@@ -1,19 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; see the file COPYING. If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
@@ -82,6 +69,7 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/srcu.h>
+#include <linux/ratelimit.h>
#include <linux/atomic.h>
@@ -115,6 +103,8 @@
return &fsnotify_conn_inode(conn)->i_fsnotify_mask;
else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
return &fsnotify_conn_mount(conn)->mnt_fsnotify_mask;
+ else if (conn->type == FSNOTIFY_OBJ_TYPE_SB)
+ return &fsnotify_conn_sb(conn)->s_fsnotify_mask;
return NULL;
}
@@ -195,6 +185,8 @@
atomic_long_inc(&inode->i_sb->s_fsnotify_inode_refs);
} else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
+ } else if (conn->type == FSNOTIFY_OBJ_TYPE_SB) {
+ fsnotify_conn_sb(conn)->s_fsnotify_mask = 0;
}
rcu_assign_pointer(*(conn->obj), NULL);
@@ -234,13 +226,13 @@
void fsnotify_put_mark(struct fsnotify_mark *mark)
{
- struct fsnotify_mark_connector *conn;
+ struct fsnotify_mark_connector *conn = READ_ONCE(mark->connector);
void *objp = NULL;
unsigned int type = FSNOTIFY_OBJ_TYPE_DETACHED;
bool free_conn = false;
/* Catch marks that were actually never attached to object */
- if (!mark->connector) {
+ if (!conn) {
if (refcount_dec_and_test(&mark->refcnt))
fsnotify_final_mark_destroy(mark);
return;
@@ -250,10 +242,9 @@
* We have to be careful so that traversals of obj_list under lock can
* safely grab mark reference.
*/
- if (!refcount_dec_and_lock(&mark->refcnt, &mark->connector->lock))
+ if (!refcount_dec_and_lock(&mark->refcnt, &conn->lock))
return;
- conn = mark->connector;
hlist_del_init_rcu(&mark->obj_list);
if (hlist_empty(&conn->list)) {
objp = fsnotify_detach_connector_from_object(conn, &type);
@@ -261,7 +252,7 @@
} else {
__fsnotify_recalc_mask(conn);
}
- mark->connector = NULL;
+ WRITE_ONCE(mark->connector, NULL);
spin_unlock(&conn->lock);
fsnotify_drop_object(type, objp);
@@ -285,6 +276,7 @@
queue_delayed_work(system_unbound_wq, &reaper_work,
FSNOTIFY_REAPER_DELAY);
}
+EXPORT_SYMBOL_GPL(fsnotify_put_mark);
/*
* Get mark reference when we found the mark via lockless traversal of object
@@ -333,13 +325,16 @@
}
bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
+ __releases(&fsnotify_mark_srcu)
{
int type;
fsnotify_foreach_obj_type(type) {
/* This can fail if mark is being removed */
- if (!fsnotify_get_mark_safe(iter_info->marks[type]))
+ if (!fsnotify_get_mark_safe(iter_info->marks[type])) {
+ __release(&fsnotify_mark_srcu);
goto fail;
+ }
}
/*
@@ -358,6 +353,7 @@
}
void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info)
+ __acquires(&fsnotify_mark_srcu)
{
int type;
@@ -434,11 +430,12 @@
void fsnotify_destroy_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group)
{
- mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
+ mutex_lock(&group->mark_mutex);
fsnotify_detach_mark(mark);
mutex_unlock(&group->mark_mutex);
fsnotify_free_mark(mark);
}
+EXPORT_SYMBOL_GPL(fsnotify_destroy_mark);
/*
* Sorting function for lists of fsnotify marks.
@@ -477,7 +474,8 @@
}
static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
- unsigned int type)
+ unsigned int type,
+ __kernel_fsid_t *fsid)
{
struct inode *inode = NULL;
struct fsnotify_mark_connector *conn;
@@ -489,6 +487,14 @@
INIT_HLIST_HEAD(&conn->list);
conn->type = type;
conn->obj = connp;
+ /* Cache fsid of filesystem containing the object */
+ if (fsid) {
+ conn->fsid = *fsid;
+ conn->flags = FSNOTIFY_CONN_FLAG_HAS_FSID;
+ } else {
+ conn->fsid.val[0] = conn->fsid.val[1] = 0;
+ conn->flags = 0;
+ }
if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
inode = igrab(fsnotify_conn_inode(conn));
/*
@@ -540,7 +546,7 @@
*/
static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
fsnotify_connp_t *connp, unsigned int type,
- int allow_dups)
+ int allow_dups, __kernel_fsid_t *fsid)
{
struct fsnotify_mark *lmark, *last = NULL;
struct fsnotify_mark_connector *conn;
@@ -549,15 +555,41 @@
if (WARN_ON(!fsnotify_valid_obj_type(type)))
return -EINVAL;
+
+ /* Backend is expected to check for zero fsid (e.g. tmpfs) */
+ if (fsid && WARN_ON_ONCE(!fsid->val[0] && !fsid->val[1]))
+ return -ENODEV;
+
restart:
spin_lock(&mark->lock);
conn = fsnotify_grab_connector(connp);
if (!conn) {
spin_unlock(&mark->lock);
- err = fsnotify_attach_connector_to_object(connp, type);
+ err = fsnotify_attach_connector_to_object(connp, type, fsid);
if (err)
return err;
goto restart;
+ } else if (fsid && !(conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID)) {
+ conn->fsid = *fsid;
+ /* Pairs with smp_rmb() in fanotify_get_fsid() */
+ smp_wmb();
+ conn->flags |= FSNOTIFY_CONN_FLAG_HAS_FSID;
+ } else if (fsid && (conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID) &&
+ (fsid->val[0] != conn->fsid.val[0] ||
+ fsid->val[1] != conn->fsid.val[1])) {
+ /*
+ * Backend is expected to check for non uniform fsid
+ * (e.g. btrfs), but maybe we missed something?
+ * Only allow setting conn->fsid once to non zero fsid.
+ * inotify and non-fid fanotify groups do not set nor test
+ * conn->fsid.
+ */
+ pr_warn_ratelimited("%s: fsid mismatch on object of type %u: "
+ "%x.%x != %x.%x\n", __func__, conn->type,
+ fsid->val[0], fsid->val[1],
+ conn->fsid.val[0], conn->fsid.val[1]);
+ err = -EXDEV;
+ goto out_err;
}
/* is mark the first mark? */
@@ -588,7 +620,12 @@
/* mark should be the last entry. last is the current last entry */
hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);
added:
- mark->connector = conn;
+ /*
+ * Since connector is attached to object using cmpxchg() we are
+ * guaranteed that connector initialization is fully visible by anyone
+ * seeing mark->connector set.
+ */
+ WRITE_ONCE(mark->connector, conn);
out_err:
spin_unlock(&conn->lock);
spin_unlock(&mark->lock);
@@ -602,7 +639,7 @@
*/
int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
fsnotify_connp_t *connp, unsigned int type,
- int allow_dups)
+ int allow_dups, __kernel_fsid_t *fsid)
{
struct fsnotify_group *group = mark->group;
int ret = 0;
@@ -623,7 +660,7 @@
fsnotify_get_mark(mark); /* for g_list */
spin_unlock(&mark->lock);
- ret = fsnotify_add_mark_list(mark, connp, type, allow_dups);
+ ret = fsnotify_add_mark_list(mark, connp, type, allow_dups, fsid);
if (ret)
goto err;
@@ -644,16 +681,17 @@
}
int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_connp_t *connp,
- unsigned int type, int allow_dups)
+ unsigned int type, int allow_dups, __kernel_fsid_t *fsid)
{
int ret;
struct fsnotify_group *group = mark->group;
mutex_lock(&group->mark_mutex);
- ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups);
+ ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups, fsid);
mutex_unlock(&group->mark_mutex);
return ret;
}
+EXPORT_SYMBOL_GPL(fsnotify_add_mark);
/*
* Given a list of marks, find the mark associated with given group. If found
@@ -680,6 +718,7 @@
spin_unlock(&conn->lock);
return NULL;
}
+EXPORT_SYMBOL_GPL(fsnotify_find_mark);
/* Clear any marks in a group with given type mask */
void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
@@ -703,7 +742,7 @@
* move marks to free to to_free list in one go and then free marks in
* to_free list one by one.
*/
- mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
+ mutex_lock(&group->mark_mutex);
list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) {
if ((1U << mark->connector->type) & type_mask)
list_move(&mark->g_list, &to_free);
@@ -712,7 +751,7 @@
clear:
while (1) {
- mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
+ mutex_lock(&group->mark_mutex);
if (list_empty(head)) {
mutex_unlock(&group->mark_mutex);
break;
@@ -776,7 +815,9 @@
refcount_set(&mark->refcnt, 1);
fsnotify_get_group(group);
mark->group = group;
+ WRITE_ONCE(mark->connector, NULL);
}
+EXPORT_SYMBOL_GPL(fsnotify_init_mark);
/*
* Destroy all marks in destroy_list, waits for SRCU period to finish before
@@ -805,3 +846,4 @@
{
flush_delayed_work(&reaper_work);
}
+EXPORT_SYMBOL_GPL(fsnotify_wait_marks_destroyed);
--
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