fsnotify: Pass fsnotify_iter_info into handle_event handler
Pass fsnotify_iter_info into ->handle_event() handler so that it can
release and reacquire SRCU lock via fsnotify_prepare_user_wait() and
fsnotify_finish_user_wait() functions. These functions also make sure
current marks are appropriately pinned so that iteration protected by
srcu in fsnotify() stays safe.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index d512ef9..c4afb6a 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -127,7 +127,8 @@
struct fsnotify_mark *vfsmount_mark,
__u32 mask, const void *data,
int data_is, u32 cookie,
- const unsigned char *file_name)
+ const unsigned char *file_name,
+ struct fsnotify_iter_info *iter_info)
{
struct fsnotify_group *group = NULL;
__u32 inode_test_mask = 0;
@@ -178,7 +179,7 @@
return group->ops->handle_event(group, to_tell, inode_mark,
vfsmount_mark, mask, data, data_is,
- file_name, cookie);
+ file_name, cookie, iter_info);
}
/*
@@ -194,8 +195,9 @@
struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
struct fsnotify_group *inode_group, *vfsmount_group;
struct fsnotify_mark_connector *inode_conn, *vfsmount_conn;
+ struct fsnotify_iter_info iter_info;
struct mount *mnt;
- int idx, ret = 0;
+ int ret = 0;
/* global tests shouldn't care about events on child only the specific event */
__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
@@ -224,7 +226,7 @@
!(mnt && test_mask & mnt->mnt_fsnotify_mask))
return 0;
- idx = srcu_read_lock(&fsnotify_mark_srcu);
+ iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
if ((mask & FS_MODIFY) ||
(test_mask & to_tell->i_fsnotify_mask)) {
@@ -284,8 +286,13 @@
vfsmount_mark = NULL;
}
}
+
+ iter_info.inode_mark = inode_mark;
+ iter_info.vfsmount_mark = vfsmount_mark;
+
ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,
- data, data_is, cookie, file_name);
+ data, data_is, cookie, file_name,
+ &iter_info);
if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
goto out;
@@ -299,7 +306,7 @@
}
ret = 0;
out:
- srcu_read_unlock(&fsnotify_mark_srcu, idx);
+ srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx);
return ret;
}