From bce7f720f4ca9d48ea4be05b49010c35e1c7f956 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Fri, 18 May 2018 11:51:52 +0530 Subject: [PATCH] f2fs: Fix deadlock in shutdown ioctl [ Upstream commit 60b2b4ee2bc01dd052f99fa9d65da2232102ef8e ] f2fs_ioc_shutdown() ioctl gets stuck in the below path when issued with F2FS_GOING_DOWN_FULLSYNC option. __switch_to+0x90/0xc4 percpu_down_write+0x8c/0xc0 freeze_super+0xec/0x1e4 freeze_bdev+0xc4/0xcc f2fs_ioctl+0xc0c/0x1ce0 f2fs_compat_ioctl+0x98/0x1f0 Signed-off-by: Sahitya Tummala Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 801111e1f8ef..249f917a494b 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1670,9 +1670,11 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg) if (get_user(in, (__u32 __user *)arg)) return -EFAULT; - ret = mnt_want_write_file(filp); - if (ret) - return ret; + if (in != F2FS_GOING_DOWN_FULLSYNC) { + ret = mnt_want_write_file(filp); + if (ret) + return ret; + } switch (in) { case F2FS_GOING_DOWN_FULLSYNC: @@ -1700,7 +1702,8 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg) } f2fs_update_time(sbi, REQ_TIME); out: - mnt_drop_write_file(filp); + if (in != F2FS_GOING_DOWN_FULLSYNC) + mnt_drop_write_file(filp); return ret; } -- 2.20.1