tests/kern/t19 and t23 fcntl posix advisory record lock tests fails

[garlick]

Problem: tests/kern/t19 fails on linux-6.9.3 (ubuntu 22.04)

$ diff -u t19.exp t19.out
--- t19.exp	2022-02-22 21:08:52.895878041 -0800
+++ t19.out	2024-07-06 07:24:47.000683222 -0700
@@ -72,16 +72,7 @@
 tfcntl2: fd: write-locked 1 byte
 tfcntl2: child forked
 tfcntl2: fd2: open (child)
-tfcntl2: fd2: write-locked rest of file
-tfcntl2: child exited normally
-tfcntl2: fd: closed
-tfcntl2: 5. Non-conflicting read and write locks CAN be held by two processes
-tfcntl2: fd: open
-tfcntl2: fd: write-locked 1 byte
-tfcntl2: child forked
-tfcntl2: fd2: open (child)
-tfcntl2: fd2: read-locked rest of file
-tfcntl2: child exited normally
-tfcntl2: fd: closed
+tfcntl2: fd2: write-lock rest of file failed: Resource temporarily unavailable
+tfcntl2: child exited with 1, aborting
 kconjoin: t19 exited with rc=0
 kconjoin: diod exited with rc=0

t23 also fails:

$ diff -u t23.exp t23.out
--- t23.exp	2022-02-22 21:08:52.895878041 -0800
+++ t23.out	2024-07-06 07:24:47.061684733 -0700
@@ -72,56 +72,6 @@
 tfcntl3: fd: open O_RDWR
 tfcntl3: fd: read-locked
 tfcntl3: fd2: open O_RDWR
-tfcntl3: fd2: write-locked
-tfcntl3: fd2: closed
-tfcntl3: fd: closed
-tfcntl3: 3. Upgrade byte range of write lock (one fd)
-tfcntl3: fd: open O_RDWR
-tfcntl3: fd: write-locked 1 byte
-tfcntl3: fd: write-locked entire file
-tfcntl3: fd: closed
-tfcntl3: 4. Downgrade byte range of write lock (one fd)
-tfcntl3: fd: open O_RDWR
-tfcntl3: fd: write-locked entire file
-tfcntl3: fd: write-locked 1 byte
-tfcntl3: fd: closed
-tfcntl3: 5. Downgrade write lock to read lock (one fd)
-tfcntl3: fd: open O_RDWR
-tfcntl3: fd: write-locked
-tfcntl3: fd: read-locked
-tfcntl3: fd: closed
-tfcntl3: 6. Read lock with O_RDONLY should succeed
-tfcntl3: fd: open O_RDONLY
-tfcntl3: fd: read-locked
-tfcntl3: fd: closed
-tfcntl3: 7. Read lock with O_WRONLY should fail
-tfcntl3: fd: open O_WRONLY
-tfcntl3: fd: fcntl F_SETLK rdlock failed: Bad file descriptor
-tfcntl3: fd: closed
-tfcntl3: 8. Write lock with O_RDONLY should fail
-tfcntl3: fd: open O_RDONLY
-tfcntl3: fd: fcntl F_SETLK wrlock failed: Bad file descriptor
-tfcntl3: fd: closed
-tfcntl3: 9. Write lock with O_WRONLY should succeed
-tfcntl3: fd: open O_WRONLY
-tfcntl3: fd: write-locked
-tfcntl3: fd: closed
-tfcntl3: 10. Write lock is not inherited across a fork
-tfcntl3: fd: open O_RDWR
-tfcntl3: fd: write-locked
-tfcntl3: child forked
-tfcntl3: fd: read-lock failed (child): Resource temporarily unavailable
-tfcntl3: child exited normally
-tfcntl3: fd: closed
-tfcntl3: 11. Write lock is dropped if another fd to same file is closed
-tfcntl3: fd: open O_RDWR
-tfcntl3: fd: write-locked
-tfcntl3: fd2: open O_RDWR
-tfcntl3: fd2: closed
-tfcntl3: child forked
-tfcntl3: fd: closed (child)
-tfcntl3: fd2: open O_RDWR (child)
-tfcntl3: fd2: read-locked (child)
-tfcntl3: child exited normally
+tfcntl3: fd2: fcntl F_SETLK wrlock failed: Resource temporarily unavailable
 kconjoin: t23 exited with rc=0
 kconjoin: diod exited with rc=0

[garlick]

Tests of record locking are not going to be successful because

/* Locking note:
 * Implement POSIX locks in terms of BSD flock locks.
 * This at least gets distributed whole-file locking to work.
 * Strategies for distributed record locking will deadlock.
 */

The reason for the expected failure should be made more obvious.