4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
[ 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 <stummala@xxxxxxxxxxxxxx>
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/f2fs/file.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1670,9 +1670,11 @@ static int f2fs_ioc_shutdown(struct file
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
}
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;
}
