Chunwei Chen 2d8a2b51dc Fix zpl_test_super race with zfs_umount ... We cannot call zpl_enter in zpl_test_super, because zpl_test_super is under spinlock so we can't sleep, and also because zpl_test_super is called without sb->s_umount taken, so it's possible we would race with zfs_umount and call zpl_enter on freed zfsvfs. Here's an stack trace when this happens: [ 2379.114837] VERIFY(cvp->cv_magic == CV_MAGIC) failed [ 2379.114845] PANIC at spl-condvar.c:497:__cv_broadcast() [ 2379.114854] Kernel panic - not syncing: VERIFY(cvp->cv_magic == CV_MAGIC) failed [ 2379.115012] Call Trace: [ 2379.115019] dump_stack+0x74/0x96 [ 2379.115024] panic+0x114/0x2f6 [ 2379.115035] spl_panic+0xcf/0xfc [spl] [ 2379.115477] __cv_broadcast+0x68/0xa0 [spl] [ 2379.115585] rrw_exit+0xb8/0x310 [zfs] [ 2379.115696] rrm_exit+0x4a/0x80 [zfs] [ 2379.115808] zpl_test_super+0xa9/0xd0 [zfs] [ 2379.115920] sget+0xd1/0x230 [ 2379.116033] zpl_mount+0xdc/0x230 [zfs] [ 2379.116037] legacy_get_tree+0x28/0x50 [ 2379.116039] vfs_get_tree+0x27/0xc0 [ 2379.116045] path_mount+0x2fe/0xa70 [ 2379.116048] do_mount+0x80/0xa0 [ 2379.116050] __x64_sys_mount+0x8b/0xe0 [ 2379.116052] do_syscall_64+0x35/0x50 [ 2379.116054] entry_SYSCALL_64_after_hwframe+0x61/0xc6 [ 2379.116057] RIP: 0033:0x7f9912e8b26a Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <david.chen@nutanix.com> Closes #15077		2023-07-20 10:30:21 -07:00
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spl	Add a delay to tearing down threads.	2023-06-26 13:57:12 -07:00
zfs	Fix zpl_test_super race with zfs_umount	2023-07-20 10:30:21 -07:00