mirror_zfs/include/sys/vdev_removal.h
Matthew Ahrens 6083f40387 panic in removal_remap test on 4K devices
If the zfs_remove_max_segment tunable is changed to be not a multiple of
the sector size, then the device removal code will malfunction and try
to create mappings that are smaller than one sector, leading to a panic.

On debug bits this assertion will fail in spa_vdev_copy_segment():
    ASSERT3U(DVA_GET_ASIZE(&dst), ==, size);

On nondebug, the system panics with a stack like:
    metaslab_free_concrete()
    metaslab_free_impl()
    metaslab_free_impl_cb()
    vdev_indirect_remap()
    free_from_removing_vdev()
    metaslab_free_impl()
    metaslab_free_dva()
    metaslab_free()

Fortunately, the default for zfs_remove_max_segment is 1MB, so this
can't occur by default.  We hit it during this test because
removal_remap.ksh changes zfs_remove_max_segment to 1KB. When testing on
4KB-sector disks, we hit the bug.

This change makes the zfs_remove_max_segment tunable more robust,
automatically rounding it up to a multiple of the sector size. We also
turn some key assertions into VERIFY's so that similar bugs would be
caught before they are encoded on disk (and thus avoid a
panic-reboot-loop).

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-61342
Closes #8893
2019-09-25 11:27:47 -07:00

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2.6 KiB
C

/*
* CDDL HEADER START
*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2014, 2019 by Delphix. All rights reserved.
*/
#ifndef _SYS_VDEV_REMOVAL_H
#define _SYS_VDEV_REMOVAL_H
#include <sys/spa.h>
#include <sys/bpobj.h>
#include <sys/vdev_indirect_mapping.h>
#include <sys/vdev_indirect_births.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct spa_vdev_removal {
uint64_t svr_vdev_id;
uint64_t svr_max_offset_to_sync[TXG_SIZE];
/* Thread performing a vdev removal. */
kthread_t *svr_thread;
/* Segments left to copy from the current metaslab. */
range_tree_t *svr_allocd_segs;
kmutex_t svr_lock;
kcondvar_t svr_cv;
boolean_t svr_thread_exit;
/*
* New mappings to write out each txg.
*/
list_t svr_new_segments[TXG_SIZE];
/*
* Ranges that were freed while a mapping was in flight. This is
* a subset of the ranges covered by vdev_im_new_segments.
*/
range_tree_t *svr_frees[TXG_SIZE];
/*
* Number of bytes which we have finished our work for
* in each txg. This could be data copied (which will be part of
* the mappings in vdev_im_new_segments), or data freed before
* we got around to copying it.
*/
uint64_t svr_bytes_done[TXG_SIZE];
/* List of leaf zap objects to be unlinked */
nvlist_t *svr_zaplist;
} spa_vdev_removal_t;
typedef struct spa_condensing_indirect {
/*
* New mappings to write out each txg.
*/
list_t sci_new_mapping_entries[TXG_SIZE];
vdev_indirect_mapping_t *sci_new_mapping;
} spa_condensing_indirect_t;
extern int spa_remove_init(spa_t *);
extern void spa_restart_removal(spa_t *);
extern int spa_condense_init(spa_t *);
extern void spa_condense_fini(spa_t *);
extern void spa_start_indirect_condensing_thread(spa_t *);
extern void spa_vdev_condense_suspend(spa_t *);
extern int spa_vdev_remove(spa_t *, uint64_t, boolean_t);
extern void free_from_removing_vdev(vdev_t *, uint64_t, uint64_t);
extern int spa_removal_get_stats(spa_t *, pool_removal_stat_t *);
extern void svr_sync(spa_t *, dmu_tx_t *);
extern void spa_vdev_remove_suspend(spa_t *);
extern int spa_vdev_remove_cancel(spa_t *);
extern void spa_vdev_removal_destroy(spa_vdev_removal_t *);
extern uint64_t spa_remove_max_segment(spa_t *);
extern int vdev_removal_max_span;
#ifdef __cplusplus
}
#endif
#endif /* _SYS_VDEV_REMOVAL_H */