Revision 6946bd636364effce06ea46fe8f8cd6e2edb004e authored by Peter Zijlstra on 27 August 2006, 08:23:31 UTC, committed by Linus Torvalds on 27 August 2006, 18:01:29 UTC
On Wed, 2006-08-09 at 07:57 +0200, Rolf Eike Beer wrote:
> =============================================
> [ INFO: possible recursive locking detected ]
> ---------------------------------------------
> parted/7929 is trying to acquire lock:
> (&bdev->bd_mutex){--..}, at: [<c105eb8d>] __blkdev_put+0x1e/0x13c
>
> but task is already holding lock:
> (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
>
> other info that might help us debug this:
> 1 lock held by parted/7929:
> #0: (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
> stack backtrace:
> [<c1003aad>] show_trace_log_lvl+0x58/0x15b
> [<c100495f>] show_trace+0xd/0x10
> [<c1004979>] dump_stack+0x17/0x1a
> [<c102dee5>] __lock_acquire+0x753/0x99c
> [<c102e3b0>] lock_acquire+0x4a/0x6a
> [<c1204501>] mutex_lock_nested+0xc8/0x20c
> [<c105eb8d>] __blkdev_put+0x1e/0x13c
> [<c105ecc4>] blkdev_put+0xa/0xc
> [<c105f18a>] do_open+0x336/0x3a8
> [<c105f21b>] blkdev_open+0x1f/0x4c
> [<c1057b40>] __dentry_open+0xc7/0x1aa
> [<c1057c91>] nameidata_to_filp+0x1c/0x2e
> [<c1057cd1>] do_filp_open+0x2e/0x35
> [<c1057dd7>] do_sys_open+0x38/0x68
> [<c1057e33>] sys_open+0x16/0x18
> [<c1002845>] sysenter_past_esp+0x56/0x8d
OK, I'm having a look here; its all new to me so bear with me.
blkdev_open() calls
do_open(bdev, ...,BD_MUTEX_NORMAL) and takes
mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_NORMAL)
then something fails, and we're thrown to:
out_first: where
if (bdev != bdev->bd_contains)
blkdev_put(bdev->bd_contains) which is
__blkdev_put(bdev->bd_contains, BD_MUTEX_NORMAL) which does
mutex_lock_nested(&bdev->bd_contains->bd_mutex, BD_MUTEX_NORMAL) <--- lockdep trigger
When going to out_first, dbev->bd_contains is either bdev or whole, and
since we take the branch it must be whole. So it seems to me the
following patch would be the right one:
[akpm@osdl.org: compile fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 7334bb4
apic.h
#ifndef __ASM_APIC_H
#define __ASM_APIC_H
#include <linux/pm.h>
#include <asm/fixmap.h>
#include <asm/apicdef.h>
#include <asm/system.h>
#define Dprintk(x...)
/*
* Debugging macros
*/
#define APIC_QUIET 0
#define APIC_VERBOSE 1
#define APIC_DEBUG 2
extern int apic_verbosity;
extern int apic_runs_main_timer;
/*
* Define the default level of output to be very little
* This can be turned up by using apic=verbose for more
* information and apic=debug for _lots_ of information.
* apic_verbosity is defined in apic.c
*/
#define apic_printk(v, s, a...) do { \
if ((v) <= apic_verbosity) \
printk(s, ##a); \
} while (0)
#ifdef CONFIG_X86_LOCAL_APIC
struct pt_regs;
/*
* Basic functions accessing APICs.
*/
static __inline void apic_write(unsigned long reg, unsigned int v)
{
*((volatile unsigned int *)(APIC_BASE+reg)) = v;
}
static __inline unsigned int apic_read(unsigned long reg)
{
return *((volatile unsigned int *)(APIC_BASE+reg));
}
static __inline__ void apic_wait_icr_idle(void)
{
while (apic_read( APIC_ICR ) & APIC_ICR_BUSY)
cpu_relax();
}
static inline void ack_APIC_irq(void)
{
/*
* ack_APIC_irq() actually gets compiled as a single instruction:
* - a single rmw on Pentium/82489DX
* - a single write on P6+ cores (CONFIG_X86_GOOD_APIC)
* ... yummie.
*/
/* Docs say use 0 for future compatibility */
apic_write(APIC_EOI, 0);
}
extern int get_maxlvt (void);
extern void clear_local_APIC (void);
extern void connect_bsp_APIC (void);
extern void disconnect_bsp_APIC (int virt_wire_setup);
extern void disable_local_APIC (void);
extern int verify_local_APIC (void);
extern void cache_APIC_registers (void);
extern void sync_Arb_IDs (void);
extern void init_bsp_APIC (void);
extern void setup_local_APIC (void);
extern void init_apic_mappings (void);
extern void smp_local_timer_interrupt (struct pt_regs * regs);
extern void setup_boot_APIC_clock (void);
extern void setup_secondary_APIC_clock (void);
extern int APIC_init_uniprocessor (void);
extern void disable_APIC_timer(void);
extern void enable_APIC_timer(void);
extern void clustered_apic_check(void);
extern void setup_APIC_extened_lvt(unsigned char lvt_off, unsigned char vector,
unsigned char msg_type, unsigned char mask);
#define K8_APIC_EXT_LVT_BASE 0x500
#define K8_APIC_EXT_INT_MSG_FIX 0x0
#define K8_APIC_EXT_INT_MSG_SMI 0x2
#define K8_APIC_EXT_INT_MSG_NMI 0x4
#define K8_APIC_EXT_INT_MSG_EXT 0x7
#define K8_APIC_EXT_LVT_ENTRY_THRESHOLD 0
extern int disable_timer_pin_1;
void smp_send_timer_broadcast_ipi(void);
void switch_APIC_timer_to_ipi(void *cpumask);
void switch_ipi_to_APIC_timer(void *cpumask);
#define ARCH_APICTIMER_STOPS_ON_C3 1
#endif /* CONFIG_X86_LOCAL_APIC */
extern unsigned boot_cpu_id;
#endif /* __ASM_APIC_H */
Computing file changes ...
