[PATCH 5.10 024/390] fs: dlm: handle -EBUSY first in lock arg validation

From: Greg Kroah-Hartman
Date: Mon Oct 24 2022 - 09:35:33 EST


From: Alexander Aring <aahringo@xxxxxxxxxx>

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@xxxxxxxxxxxxxxx
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/dlm/lock.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2888,24 +2888,24 @@ 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)
+ if (lkb->lkb_status != DLM_LKSTS_GRANTED)
goto out;

- if (args->flags & DLM_LKF_QUECVT &&
- !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
+ if (lkb->lkb_wait_type)
goto out;

- rv = -EBUSY;
- if (lkb->lkb_status != DLM_LKSTS_GRANTED)
+ if (is_overlap(lkb))
goto out;

- if (lkb->lkb_wait_type)
+ rv = -EINVAL;
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY)
goto out;

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