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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-26 23:40:55 +07:00
512875bd96
This patch fixes a panic on shrinking a DM device if there is outstanding I/O to the part of the device that is being removed. (Normally this doesn't happen - a filesystem would be resized first, for example.) The bug is that __clone_and_map() assumes dm_table_find_target() always returns a valid pointer. It may fail if a bio arrives from the block layer but its target sector is no longer included in the DM btree. This patch appends an empty entry to table->targets[] which will be returned by a lookup beyond the end of the device. After calling dm_table_find_target(), __clone_and_map() and target_message() check for this condition using dm_target_is_valid(). Sample test script to trigger oops:
191 lines
4.9 KiB
C
191 lines
4.9 KiB
C
/*
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* Internal header file for device mapper
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*
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* Copyright (C) 2001, 2002 Sistina Software
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the LGPL.
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*/
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#ifndef DM_INTERNAL_H
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#define DM_INTERNAL_H
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#include <linux/fs.h>
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#include <linux/device-mapper.h>
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#include <linux/list.h>
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#include <linux/blkdev.h>
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#include <linux/hdreg.h>
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#define DM_NAME "device-mapper"
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#define DMERR(f, arg...) \
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printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
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#define DMERR_LIMIT(f, arg...) \
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do { \
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if (printk_ratelimit()) \
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printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
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f "\n", ## arg); \
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} while (0)
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#define DMWARN(f, arg...) \
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printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
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#define DMWARN_LIMIT(f, arg...) \
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do { \
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if (printk_ratelimit()) \
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printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
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f "\n", ## arg); \
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} while (0)
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#define DMINFO(f, arg...) \
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printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
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#define DMINFO_LIMIT(f, arg...) \
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do { \
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if (printk_ratelimit()) \
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printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
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"\n", ## arg); \
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} while (0)
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#ifdef CONFIG_DM_DEBUG
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# define DMDEBUG(f, arg...) \
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printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
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# define DMDEBUG_LIMIT(f, arg...) \
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do { \
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if (printk_ratelimit()) \
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printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
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"\n", ## arg); \
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} while (0)
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#else
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# define DMDEBUG(f, arg...) do {} while (0)
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# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
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#endif
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#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
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0 : scnprintf(result + sz, maxlen - sz, x))
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#define SECTOR_SHIFT 9
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/*
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* Definitions of return values from target end_io function.
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*/
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#define DM_ENDIO_INCOMPLETE 1
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#define DM_ENDIO_REQUEUE 2
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/*
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* Definitions of return values from target map function.
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*/
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#define DM_MAPIO_SUBMITTED 0
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#define DM_MAPIO_REMAPPED 1
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#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
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/*
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* Suspend feature flags
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*/
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#define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
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#define DM_SUSPEND_NOFLUSH_FLAG (1 << 1)
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/*
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* List of devices that a metadevice uses and should open/close.
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*/
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struct dm_dev {
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struct list_head list;
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atomic_t count;
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int mode;
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struct block_device *bdev;
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char name[16];
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};
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struct dm_table;
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/*-----------------------------------------------------------------
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* Internal table functions.
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*---------------------------------------------------------------*/
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void dm_table_event_callback(struct dm_table *t,
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void (*fn)(void *), void *context);
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struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
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struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
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void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
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struct list_head *dm_table_get_devices(struct dm_table *t);
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void dm_table_presuspend_targets(struct dm_table *t);
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void dm_table_postsuspend_targets(struct dm_table *t);
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int dm_table_resume_targets(struct dm_table *t);
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int dm_table_any_congested(struct dm_table *t, int bdi_bits);
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void dm_table_unplug_all(struct dm_table *t);
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/*
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* To check the return value from dm_table_find_target().
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*/
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#define dm_target_is_valid(t) ((t)->table)
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/*-----------------------------------------------------------------
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* A registry of target types.
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*---------------------------------------------------------------*/
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int dm_target_init(void);
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void dm_target_exit(void);
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struct target_type *dm_get_target_type(const char *name);
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void dm_put_target_type(struct target_type *t);
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int dm_target_iterate(void (*iter_func)(struct target_type *tt,
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void *param), void *param);
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/*-----------------------------------------------------------------
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* Useful inlines.
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*---------------------------------------------------------------*/
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static inline int array_too_big(unsigned long fixed, unsigned long obj,
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unsigned long num)
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{
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return (num > (ULONG_MAX - fixed) / obj);
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}
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/*
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* Ceiling(n / sz)
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*/
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#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
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#define dm_sector_div_up(n, sz) ( \
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{ \
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sector_t _r = ((n) + (sz) - 1); \
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sector_div(_r, (sz)); \
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_r; \
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} \
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)
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/*
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* ceiling(n / size) * size
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*/
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#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
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static inline sector_t to_sector(unsigned long n)
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{
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return (n >> 9);
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}
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static inline unsigned long to_bytes(sector_t n)
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{
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return (n << 9);
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}
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int dm_split_args(int *argc, char ***argvp, char *input);
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/*
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* The device-mapper can be driven through one of two interfaces;
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* ioctl or filesystem, depending which patch you have applied.
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*/
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int dm_interface_init(void);
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void dm_interface_exit(void);
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/*
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* Targets for linear and striped mappings
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*/
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int dm_linear_init(void);
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void dm_linear_exit(void);
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int dm_stripe_init(void);
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void dm_stripe_exit(void);
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void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
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union map_info *dm_get_mapinfo(struct bio *bio);
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int dm_open_count(struct mapped_device *md);
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int dm_lock_for_deletion(struct mapped_device *md);
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#endif
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