freebsd-dev/include/sys/zvol.h
Chunwei Chen 040dab9939 Suspend/resume zvol for recv and rollback
When doing recv and rollback, dsl_dataset_clone_swap_sync_impl will be
called to swap out the ds_objset and do dmu_objset_evict on the old one.
However, currently zv->zv_objset will not be swapped out accordingly, so
if anyone currently holds a fd on the zvol, we risk hitting a use-after-free.

We fix this by introducing the suspend and resume mechanism of zsb to
zv.  Before recv or rollback, we use zvol_suspend to block all access to
zv_objset and shut it down. After the recv or rollback, we use zvol_resume
to swap in zv_objset with the new ds_objset and unblock the access.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #4866 
Closes #5609
2017-01-19 13:56:36 -08:00

62 lines
2.2 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
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*
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* If applicable, add the following below this CDDL HEADER, with the
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* CDDL HEADER END
*/
/*
* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2016 Actifio, Inc. All rights reserved.
*/
#ifndef _SYS_ZVOL_H
#define _SYS_ZVOL_H
#include <sys/zfs_context.h>
#define ZVOL_OBJ 1ULL
#define ZVOL_ZAP_OBJ 2ULL
#define SPEC_MAXOFFSET_T ((1LL << ((NBBY * sizeof (daddr32_t)) + \
DEV_BSHIFT - 1)) - 1)
extern void zvol_create_minors(spa_t *spa, const char *name, boolean_t async);
extern void zvol_remove_minors(spa_t *spa, const char *name, boolean_t async);
extern void zvol_rename_minors(spa_t *spa, const char *oldname,
const char *newname, boolean_t async);
#ifdef _KERNEL
typedef struct zvol_state zvol_state_t;
extern int zvol_check_volsize(uint64_t volsize, uint64_t blocksize);
extern int zvol_check_volblocksize(const char *name, uint64_t volblocksize);
extern int zvol_get_stats(objset_t *os, nvlist_t *nv);
extern boolean_t zvol_is_zvol(const char *);
extern void zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
extern int zvol_set_volsize(const char *, uint64_t);
extern int zvol_set_volblocksize(const char *, uint64_t);
extern int zvol_set_snapdev(const char *, zprop_source_t, uint64_t);
extern zvol_state_t *zvol_suspend(const char *);
extern int zvol_resume(zvol_state_t *);
extern void *zvol_tag(zvol_state_t *);
extern int zvol_init(void);
extern void zvol_fini(void);
#endif /* _KERNEL */
#endif /* _SYS_ZVOL_H */