Commit 8b4021fa authored by David Teigland's avatar David Teigland Committed by Steven Whitehouse
Browse files

[DLM] canceling deadlocked lock



Add a function that can be used through libdlm by a system daemon to cancel
another process's deadlocked lock.  A completion ast with EDEADLK is returned
to the process waiting for the lock.
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 84d8cd69
......@@ -216,6 +216,7 @@ struct dlm_args {
#define DLM_IFL_ENDOFLIFE 0x00200000
#define DLM_IFL_WATCH_TIMEWARN 0x00400000
#define DLM_IFL_TIMEOUT_CANCEL 0x00800000
#define DLM_IFL_DEADLOCK_CANCEL 0x01000000
#define DLM_IFL_USER 0x00000001
#define DLM_IFL_ORPHAN 0x00000002
......
......@@ -300,6 +300,11 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
rv = -ETIMEDOUT;
}
if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
rv = -EDEADLK;
}
lkb->lkb_lksb->sb_status = rv;
lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
......@@ -4450,6 +4455,54 @@ int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
return error;
}
int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
{
struct dlm_lkb *lkb;
struct dlm_args args;
struct dlm_user_args *ua;
struct dlm_rsb *r;
int error;
dlm_lock_recovery(ls);
error = find_lkb(ls, lkid, &lkb);
if (error)
goto out;
ua = (struct dlm_user_args *)lkb->lkb_astparam;
error = set_unlock_args(flags, ua, &args);
if (error)
goto out_put;
/* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
r = lkb->lkb_resource;
hold_rsb(r);
lock_rsb(r);
error = validate_unlock_args(lkb, &args);
if (error)
goto out_r;
lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
error = _cancel_lock(r, lkb);
out_r:
unlock_rsb(r);
put_rsb(r);
if (error == -DLM_ECANCEL)
error = 0;
/* from validate_unlock_args() */
if (error == -EBUSY)
error = 0;
out_put:
dlm_put_lkb(lkb);
out:
dlm_unlock_recovery(ls);
return error;
}
/* lkb's that are removed from the waiters list by revert are just left on the
orphans list with the granted orphan locks, to be freed by purge */
......
......@@ -49,6 +49,7 @@ int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
uint32_t flags, uint32_t lkid);
int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,
int nodeid, int pid);
int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid);
void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc);
static inline int is_master(struct dlm_rsb *r)
......
......@@ -156,6 +156,7 @@ static int lkb_is_endoflife(struct dlm_lkb *lkb, int sb_status, int type)
return 1;
case -DLM_ECANCEL:
case -ETIMEDOUT:
case -EDEADLK:
if (lkb->lkb_grmode == DLM_LOCK_IV)
return 1;
break;
......@@ -320,6 +321,22 @@ static int device_user_unlock(struct dlm_user_proc *proc,
return error;
}
static int device_user_deadlock(struct dlm_user_proc *proc,
struct dlm_lock_params *params)
{
struct dlm_ls *ls;
int error;
ls = dlm_find_lockspace_local(proc->lockspace);
if (!ls)
return -ENOENT;
error = dlm_user_deadlock(ls, params->flags, params->lkid);
dlm_put_lockspace(ls);
return error;
}
static int create_misc_device(struct dlm_ls *ls, char *name)
{
int error, len;
......@@ -545,6 +562,14 @@ static ssize_t device_write(struct file *file, const char __user *buf,
error = device_user_unlock(proc, &kbuf->i.lock);
break;
case DLM_USER_DEADLOCK:
if (!proc) {
log_print("no locking on control device");
goto out_sig;
}
error = device_user_deadlock(proc, &kbuf->i.lock);
break;
case DLM_USER_CREATE_LOCKSPACE:
if (proc) {
log_print("create/remove only on control device");
......
......@@ -92,6 +92,7 @@ struct dlm_lock_result {
#define DLM_USER_CREATE_LOCKSPACE 4
#define DLM_USER_REMOVE_LOCKSPACE 5
#define DLM_USER_PURGE 6
#define DLM_USER_DEADLOCK 7
/* Arbitrary length restriction */
#define MAX_LS_NAME_LEN 64
......
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