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>
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pci.h
#ifndef __x8664_PCI_H
#define __x8664_PCI_H
#include <asm/io.h>
#ifdef __KERNEL__
#include <linux/mm.h> /* for struct page */
/* Can be used to override the logic in pci_scan_bus for skipping
already-configured bus numbers - to be used for buggy BIOSes
or architectures with incomplete PCI setup by the loader */
#ifdef CONFIG_PCI
extern unsigned int pcibios_assign_all_busses(void);
#else
#define pcibios_assign_all_busses() 0
#endif
#define pcibios_scan_all_fns(a, b) 0
extern unsigned long pci_mem_start;
#define PCIBIOS_MIN_IO 0x1000
#define PCIBIOS_MIN_MEM (pci_mem_start)
#define PCIBIOS_MIN_CARDBUS_IO 0x4000
void pcibios_config_init(void);
struct pci_bus * pcibios_scan_root(int bus);
extern int (*pci_config_read)(int seg, int bus, int dev, int fn, int reg, int len, u32 *value);
extern int (*pci_config_write)(int seg, int bus, int dev, int fn, int reg, int len, u32 value);
void pcibios_set_master(struct pci_dev *dev);
void pcibios_penalize_isa_irq(int irq, int active);
struct irq_routing_table *pcibios_get_irq_routing_table(void);
int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq);
#include <linux/types.h>
#include <linux/slab.h>
#include <asm/scatterlist.h>
#include <linux/string.h>
#include <asm/page.h>
extern void pci_iommu_alloc(void);
extern int iommu_setup(char *opt);
/* The PCI address space does equal the physical memory
* address space. The networking and block device layers use
* this boolean for bounce buffer decisions
*
* On AMD64 it mostly equals, but we set it to zero if a hardware
* IOMMU (gart) of sotware IOMMU (swiotlb) is available.
*/
#define PCI_DMA_BUS_IS_PHYS (dma_ops->is_phys)
#if defined(CONFIG_IOMMU) || defined(CONFIG_CALGARY_IOMMU)
/*
* x86-64 always supports DAC, but sometimes it is useful to force
* devices through the IOMMU to get automatic sg list merging.
* Optional right now.
*/
extern int iommu_sac_force;
#define pci_dac_dma_supported(pci_dev, mask) (!iommu_sac_force)
#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME) \
dma_addr_t ADDR_NAME;
#define DECLARE_PCI_UNMAP_LEN(LEN_NAME) \
__u32 LEN_NAME;
#define pci_unmap_addr(PTR, ADDR_NAME) \
((PTR)->ADDR_NAME)
#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL) \
(((PTR)->ADDR_NAME) = (VAL))
#define pci_unmap_len(PTR, LEN_NAME) \
((PTR)->LEN_NAME)
#define pci_unmap_len_set(PTR, LEN_NAME, VAL) \
(((PTR)->LEN_NAME) = (VAL))
#else
/* No IOMMU */
#define pci_dac_dma_supported(pci_dev, mask) 1
#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)
#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)
#define pci_unmap_addr(PTR, ADDR_NAME) (0)
#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL) do { } while (0)
#define pci_unmap_len(PTR, LEN_NAME) (0)
#define pci_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
#endif
#include <asm-generic/pci-dma-compat.h>
static inline dma64_addr_t
pci_dac_page_to_dma(struct pci_dev *pdev, struct page *page, unsigned long offset, int direction)
{
return ((dma64_addr_t) page_to_phys(page) +
(dma64_addr_t) offset);
}
static inline struct page *
pci_dac_dma_to_page(struct pci_dev *pdev, dma64_addr_t dma_addr)
{
return virt_to_page(__va(dma_addr));
}
static inline unsigned long
pci_dac_dma_to_offset(struct pci_dev *pdev, dma64_addr_t dma_addr)
{
return (dma_addr & ~PAGE_MASK);
}
static inline void
pci_dac_dma_sync_single_for_cpu(struct pci_dev *pdev, dma64_addr_t dma_addr, size_t len, int direction)
{
}
static inline void
pci_dac_dma_sync_single_for_device(struct pci_dev *pdev, dma64_addr_t dma_addr, size_t len, int direction)
{
flush_write_buffers();
}
#ifdef CONFIG_PCI
static inline void pci_dma_burst_advice(struct pci_dev *pdev,
enum pci_dma_burst_strategy *strat,
unsigned long *strategy_parameter)
{
*strat = PCI_DMA_BURST_INFINITY;
*strategy_parameter = ~0UL;
}
#endif
#define HAVE_PCI_MMAP
extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
static inline void pcibios_add_platform_entries(struct pci_dev *dev)
{
}
#endif /* __KERNEL__ */
/* generic pci stuff */
#ifdef CONFIG_PCI
#include <asm-generic/pci.h>
#endif
#endif /* __x8664_PCI_H */
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