Hi Willy,
some months ago, after your fs/locks.c cleanup, and after
troubles we had with getting tests for non-blocking vs. blocking
calls correct, I wrote following patch. If you are still
interested in cleaning up fs/locks.c, can you review it, and
either dump to the floor, or send to Linus?
With old version, we do wait_event_interruptible()
when lock function returned -EAGAIN and we did blocking call.
Patch below changes locking code to return -EAGAIN if
wait_event_interruptible() should not called, and -ERESTARTSYS
if wait_event_interruptible() should be called (that is,
locking code called locks_insert_block()). So now calling
rule is simple: if you got -ERESTARTSYS, you must do
wait_event_interruptible, otherwise you have error code to
return to userspace.
I choosed ERESTARTSYS just arbitrary: it was not used by
currentl locking code, it must not be returned to userspace,
and it already exists.
Thanks,
Petr Vandrovec
vandrove@vc.cvut.cz
diff -urdN linux/fs/locks.c linux/fs/locks.c
--- linux/fs/locks.c 2002-11-20 18:33:14.000000000 +0000
+++ linux/fs/locks.c 2002-11-20 18:42:01.000000000 +0000
@@ -678,7 +678,7 @@
for (;;) {
error = posix_lock_file(filp, &fl);
- if (error != -EAGAIN)
+ if (error != -ERESTARTSYS)
break;
error = wait_event_interruptible(fl.fl_wait, !fl.fl_next);
if (!error) {
@@ -749,6 +749,7 @@
error = -EAGAIN;
if (new_fl->fl_flags & FL_SLEEP) {
locks_insert_block(fl, new_fl);
+ error = -ERESTARTSYS;
}
goto out;
}
@@ -812,7 +813,7 @@
error = -EDEADLK;
if (posix_locks_deadlock(request, fl))
goto out;
- error = -EAGAIN;
+ error = -ERESTARTSYS;
locks_insert_block(fl, request);
goto out;
}
@@ -1295,7 +1296,7 @@
for (;;) {
error = flock_lock_file(filp, lock);
- if ((error != -EAGAIN) || (cmd & LOCK_NB))
+ if (error != -ERESTARTSYS)
break;
error = wait_event_interruptible(lock->fl_wait, !lock->fl_next);
if (!error)
@@ -1453,7 +1454,7 @@
for (;;) {
error = posix_lock_file(filp, file_lock);
- if ((error != -EAGAIN) || (cmd == F_SETLK))
+ if (error != -ERESTARTSYS)
break;
error = wait_event_interruptible(file_lock->fl_wait,
!file_lock->fl_next);
@@ -1593,7 +1594,7 @@
for (;;) {
error = posix_lock_file(filp, file_lock);
- if ((error != -EAGAIN) || (cmd == F_SETLK64))
+ if (error != -ERESTARTSYS)
break;
error = wait_event_interruptible(file_lock->fl_wait,
!file_lock->fl_next);
-
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This archive was generated by hypermail 2b29 : Sat Nov 23 2002 - 22:00:33 EST