Hi Hillf, On 7/16/22 07:27, Helge Deller wrote: > On 7/15/22 15:33, Hillf Danton wrote: >> On Fri, 15 Jul 2022 10:18:23 +0200 Helge Deller wrote: > and this was the output: > > [108563.953441] IAOQ[1]: dentry_free+0xc4/0x338 > [108564.005441] RP(r2): __dentry_kill+0x284/0x2e8 > [108564.057443] Backtrace: > [108564.089454] [<000000004073bab0>] __dentry_kill+0x284/0x2e8 > [108564.157445] [<000000004073d2f8>] dput+0x334/0x5a8 > [108564.213444] [<00000000407267a4>] step_into+0x790/0xa88 > [108564.277444] [<0000000040727084>] walk_component+0xa8/0x330 > [108564.345443] [<00000000407275f8>] link_path_walk.part.0.constprop.0+0x2ec/0x4d0 > [108564.437443] [<0000000040728254>] path_openat+0x150/0x1ba8 > [108564.501441] [<000000004072ba28>] do_filp_open+0x9c/0x198 > [108564.569441] [<0000000040701d20>] do_sys_openat2+0x14c/0x2a8 > [108564.637441] [<0000000040702654>] compat_sys_openat+0x58/0xb8 > [108564.705440] [<0000000040303e30>] syscall_exit+0x0/0x10 > [108564.769444] > [108564.789435] ---[ end trace 0000000000000000 ]--- > [108564.845444] dentry = 000000031624e6c0 > [108564.889437] spin_is_locked(&dentry->d_lock) = 0 > [108564.945436] dname_external(dentry) = 0 > [108564.993436] dentry->d_flags & DCACHE_NORCU = 0 > [108565.045446] dentry->d_name.len = 3 > [108565.089435] dentry->d_name.hash = 89116695 > [108565.137435] dentry->d_lockref.count = -128 > [108565.189434] dentry->d_flags = 32776 > [108565.233435] dentry->d_inode = 0000000000000000 > [108565.285429] dentry->d_parent = 000000022ef756c0 > [108565.341434] dentry->d_u.d_rcu = 0x416be770 > >> Add debug info to the diff below. Cut the first BUG_ON off if it>> triggers and see if the second one can be hit. I used WARN_ON() instead of BUG_ON(). With that, both triggered, first the first one, then the second one. Full log is here: http://dellerweb.de/testcases/minicom.dcache.crash.6-warn Helge >> +++ y/fs/dcache.>> @@ -605,8 +605,10 @@ static void __dentry_kill(struct dentry >> spin_unlock(&parent->d_lock); >> if (dentry->d_inode) >> dentry_unlink_inode(dentry); >> - else >> + else { >> + BUG_ON(!hlist_unhashed(&dentry->d_u.d_alias)); >> spin_unlock(&dentry->d_lock); >> + } >> this_cpu_dec(nr_dentry); >> if (dentry->d_op && dentry->d_op->d_release) >> dentry->d_op->d_release(dentry); >> @@ -616,6 +618,7 @@ static void __dentry_kill(struct dentry >> dentry->d_flags |= DCACHE_MAY_FREE; >> can_free = false; >> } >> + BUG_ON(!hlist_unhashed(&dentry->d_u.d_alias)); >> spin_unlock(&dentry->d_lock); >> if (likely(can_free)) >> dentry_free(dentry);
