https://bugzilla.novell.com/show_bug.cgi?id=463465 User novell.com@kleinmanns.com added comment https://bugzilla.novell.com/show_bug.cgi?id=463465#c1 Summary: CIFS: cifsd hangs in uninterruptible sleep Product: openSUSE 11.1 Version: Final Platform: i686 URL: https://bugzilla.samba.org/show_bug.cgi?id=5989 OS/Version: openSUSE 11.1 Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: novell.com@kleinmanns.com QAContact: qa@suse.de Found By: Customer After mounting and unmounting a remote cifs share, three cifs kernel processes stay in the process table: $ ps aux [...] root 11351 0.0 0.0 0 0 ? S< 22:30 0:00 [cifsoplockd] root 11352 0.0 0.0 0 0 ? S< 22:30 0:00 [cifsdnotifyd] root 11357 0.7 0.0 0 0 ? D< 22:30 0:00 [cifsd] [...] cifsd is in an uninterruptible sleep waiting for i/o (but what i/o?), without any open files: $ lsof -p 11357 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME cifsd 11357 root cwd DIR 22,3 536 2 / cifsd 11357 root rtd DIR 22,3 536 2 / cifsd 11357 root txt unknown /proc/11357/exe In this state, cifsd is not interruptible by any signals, of course. An attempt to kill it by $ modprobe -r cifs results in removing the kernel module (!) as well as the sleeping processes cifsoplockd and cifsdnotifyd, but puts this error message into the syslog: Dec 23 22:36:04 lex kernel: slab error in kmem_cache_destroy(): cache `cifs_request': Can't free all Dec 23 22:36:04 lex kernel: Pid: 11436, comm: modprobe Tainted: G 2.6.27.7-9-default #1 Dec 23 22:36:04 lex kernel: [<c0106570>] dump_trace+0x6b/0x249 Dec 23 22:36:04 lex kernel: [<c01070a5>] show_trace+0x20/0x39 Dec 23 22:36:04 lex kernel: [<c0343c02>] dump_stack+0x71/0x76 Dec 23 22:36:04 lex kernel: [<c018c376>] kmem_cache_destroy+0x88/0xd6 Dec 23 22:36:04 lex kernel: [<d10dc84e>] cifs_destroy_request_bufs+0x14/0x28 [cifs] Dec 23 22:36:04 lex kernel: [<d10fc79c>] exit_cifs+0x3c/0xc8 [cifs] Dec 23 22:36:04 lex kernel: [<c014cbf9>] sys_delete_module+0x1ce/0x228 Dec 23 22:36:04 lex kernel: [<c0104d92>] syscall_call+0x7/0xb Dec 23 22:36:04 lex kernel: [<b7ec7d24>] 0xb7ec7d24 Dec 23 22:36:04 lex kernel: ======================= Dec 23 22:36:04 lex kernel: slab error in kmem_cache_destroy(): cache `cifs_small_rq': Can't free all Dec 23 22:36:04 lex kernel: Pid: 11436, comm: modprobe Tainted: G 2.6.27.7-9-default #1 Dec 23 22:36:04 lex kernel: [<c0106570>] dump_trace+0x6b/0x249 Dec 23 22:36:04 lex kernel: [<c01070a5>] show_trace+0x20/0x39 Dec 23 22:36:04 lex kernel: [<c0343c02>] dump_stack+0x71/0x76 Dec 23 22:36:04 lex kernel: [<c018c376>] kmem_cache_destroy+0x88/0xd6 Dec 23 22:36:04 lex kernel: [<d10fc79c>] exit_cifs+0x3c/0xc8 [cifs] Dec 23 22:36:04 lex kernel: [<c014cbf9>] sys_delete_module+0x1ce/0x228 Dec 23 22:36:04 lex kernel: [<c0104d92>] syscall_call+0x7/0xb Dec 23 22:36:04 lex kernel: [<b7ec7d24>] 0xb7ec7d24 Dec 23 22:36:04 lex kernel: ======================= Re-inserting the module fails: Dec 23 22:43:42 lex kernel: kmem_cache_create: duplicate cache cifs_request Dec 23 22:43:42 lex kernel: Pid: 11472, comm: modprobe Tainted: G 2.6.27.7-9-default #1 Dec 23 22:43:42 lex kernel: [<c0106570>] dump_trace+0x6b/0x249 Dec 23 22:43:42 lex kernel: [<c01070a5>] show_trace+0x20/0x39 Dec 23 22:43:42 lex kernel: [<c0343c02>] dump_stack+0x71/0x76 Dec 23 22:43:42 lex kernel: [<c018c4a0>] kmem_cache_create+0xdc/0x3c4 Dec 23 22:43:42 lex kernel: [<d10dc8d0>] cifs_init_request_bufs+0x5c/0x191 [cifs] Dec 23 22:43:42 lex kernel: [<d107c35d>] init_cifs+0x35d/0x368 [cifs] Dec 23 22:43:42 lex kernel: [<c010112b>] _stext+0x3b/0x127 Dec 23 22:43:42 lex kernel: [<c014c8bf>] sys_init_module+0x8a/0x19e Dec 23 22:43:42 lex kernel: [<c0104d92>] syscall_call+0x7/0xb Dec 23 22:43:42 lex kernel: [<b7e6ff0e>] 0xb7e6ff0e Dec 23 22:43:42 lex kernel: ======================= Dec 23 22:43:42 lex modprobe: FATAL: Error inserting cifs (/lib/modules/2.6.27.7-9-default/kernel/fs/ Dec 23 22:43:50 lex kernel: kmem_cache_create: duplicate cache cifs_request Dec 23 22:43:50 lex kernel: Pid: 11478, comm: modprobe Tainted: G 2.6.27.7-9-default #1 Dec 23 22:43:50 lex kernel: [<c0106570>] dump_trace+0x6b/0x249 Dec 23 22:43:50 lex kernel: [<c01070a5>] show_trace+0x20/0x39 Dec 23 22:43:50 lex kernel: [<c0343c02>] dump_stack+0x71/0x76 Dec 23 22:43:50 lex kernel: [<c018c4a0>] kmem_cache_create+0xdc/0x3c4 Dec 23 22:43:50 lex kernel: [<d10dc8d0>] cifs_init_request_bufs+0x5c/0x191 [cifs] Dec 23 22:43:50 lex kernel: [<d107c35d>] init_cifs+0x35d/0x368 [cifs] Dec 23 22:43:50 lex kernel: [<c010112b>] _stext+0x3b/0x127 Dec 23 22:43:50 lex kernel: [<c014c8bf>] sys_init_module+0x8a/0x19e Dec 23 22:43:50 lex kernel: [<c0104d92>] syscall_call+0x7/0xb Dec 23 22:43:50 lex kernel: [<b7f54f0e>] 0xb7f54f0e Dec 23 22:43:50 lex kernel: ======================= After rebooting, I could mount cifs shares again. 'Mount, unmount, mount, unmount, mount' results in two "uninterruptible sleep" cifsd processes (remainder of first and second unmount) and one sleeping cifsd process (responsible for the third mounted, not yet unmounted share). I already reported this bug upstream https://bugzilla.samba.org/show_bug.cgi?id=5989, but today I noticed that a self-compiled plain vanilla 2.6.28 kernel works fine: The cifsd kernel process disappears after unmounting all cifs shares. I believe that the uninterruptible cifsd process is responsible for hibernation failing, but I am not sure yet (more testing required). -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.