[PATCH 5.19 037/717] fs: dlm: handle -EBUSY first in lock arg validation

Greg Kroah-Hartman
2022-10-22T07:40:48Z

From: Alexander Aring <aahringo@redhat.com>

commit 44637ca41d551d409a481117b07fa209b330fca9 upstream.

During lock arg validation, first check for -EBUSY cases, then for
-EINVAL cases. The -EINVAL checks look at lkb state variables
which are not stable when an lkb is busy and would cause an
-EBUSY result, e.g. lkb->lkb_grmode.

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/dlm/lock.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2920,17 +2920,9 @@ static int set_unlock_args(uint32_t flag
static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
struct dlm_args *args)
{
- int rv = -EINVAL;
+ int rv = -EBUSY;

if (args->flags & DLM_LKF_CONVERT) {
- if (lkb->lkb_flags & DLM_IFL_MSTCPY)
- goto out;
-
- if (args->flags & DLM_LKF_QUECVT &&
- !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
- goto out;
-
- rv = -EBUSY;
if (lkb->lkb_status != DLM_LKSTS_GRANTED)
goto out;

@@ -2940,6 +2932,14 @@ static int validate_lock_args(struct dlm

if (is_overlap(lkb))
goto out;
+
+ rv = -EINVAL;
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY)
+ goto out;
+
+ if (args->flags & DLM_LKF_QUECVT &&
+ !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
+ goto out;
}

lkb->lkb_exflags = args->flags;