Jiachen Zhang eb06c01c33 ovl: drop WARN_ON() dentry is NULL in ovl_encode_fh() ... commit dd524b7f31 upstream. Some code paths cannot guarantee the inode have any dentry alias. So WARN_ON() all !dentry may flood the kernel logs. For example, when an overlayfs inode is watched by inotifywait (1), and someone is trying to read the /proc/$(pidof inotifywait)/fdinfo/INOTIFY_FD, at that time if the dentry has been reclaimed by kernel (such as echo 2 > /proc/sys/vm/drop_caches), there will be a WARN_ON(). The printed call stack would be like: ? show_mark_fhandle+0xf0/0xf0 show_mark_fhandle+0x4a/0xf0 ? show_mark_fhandle+0xf0/0xf0 ? seq_vprintf+0x30/0x50 ? seq_printf+0x53/0x70 ? show_mark_fhandle+0xf0/0xf0 inotify_fdinfo+0x70/0x90 show_fdinfo.isra.4+0x53/0x70 seq_show+0x130/0x170 seq_read+0x153/0x440 vfs_read+0x94/0x150 ksys_read+0x5f/0xe0 do_syscall_64+0x59/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 So let's drop WARN_ON() to avoid kernel log flooding. Reported-by: Hongbo Yin <yinhongbo@bytedance.com> Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com> Signed-off-by: Tianci Zhang <zhangtianci.1997@bytedance.com> Fixes: 8ed5eec9d6 ("ovl: encode pure upper file handles") Cc: <stable@vger.kernel.org> # v4.16 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-08-17 14:40:09 +02:00
..
copy_up.c	ovl: don't fail copy up if no fileattr support on upper	2022-01-14 16:57:56 +01:00
dir.c	ovl: fix warning in ovl_create_real()	2021-11-04 10:55:34 +01:00
export.c	ovl: drop WARN_ON() dentry is NULL in ovl_encode_fh()	2022-08-17 14:40:09 +02:00
file.c	overlayfs update for 5.16	2021-11-09 10:51:12 -08:00
inode.c	ovl: fix filattr copy-up failure	2021-11-04 14:04:52 +01:00
Kconfig
Makefile
namei.c
overlayfs.h	ovl: fix warning in ovl_create_real()	2021-11-04 10:55:34 +01:00
ovl_entry.h
readdir.c
super.c	fs: allocate inode by using alloc_inode_sb()	2022-03-22 15:57:03 -07:00
util.c