8794846a91
Allow clients of blockif to register a resize callback handler. When a callback is registered, register an EVFILT_VNODE kevent watching the backing store for a change in the file's attributes. If the size has changed when the kevent fires, invoke the clients' callback. Currently resize detection is limited to backing stores that support EVFILT_VNODE kevents such as regular files. Reviewed by: grehan, markj MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D30504
97 lines
3.6 KiB
C
97 lines
3.6 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2013 Peter Grehan <grehan@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* The block API to be used by bhyve block-device emulations. The routines
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* are thread safe, with no assumptions about the context of the completion
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* callback - it may occur in the caller's context, or asynchronously in
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* another thread.
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*/
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#ifndef _BLOCK_IF_H_
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#define _BLOCK_IF_H_
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#include <sys/nv.h>
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#include <sys/uio.h>
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#include <sys/unistd.h>
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struct vm_snapshot_meta;
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/*
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* BLOCKIF_IOV_MAX is the maximum number of scatter/gather entries in
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* a single request. BLOCKIF_RING_MAX is the maxmimum number of
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* pending requests that can be queued.
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*/
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#define BLOCKIF_IOV_MAX 128 /* not practical to be IOV_MAX */
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#define BLOCKIF_RING_MAX 128
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struct blockif_req {
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int br_iovcnt;
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off_t br_offset;
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ssize_t br_resid;
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void (*br_callback)(struct blockif_req *req, int err);
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void *br_param;
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struct iovec br_iov[BLOCKIF_IOV_MAX];
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};
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struct blockif_ctxt;
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typedef void blockif_resize_cb(struct blockif_ctxt *, void *, size_t);
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int blockif_legacy_config(nvlist_t *nvl, const char *opts);
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struct blockif_ctxt *blockif_open(nvlist_t *nvl, const char *ident);
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int blockif_register_resize_callback(struct blockif_ctxt *bc,
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blockif_resize_cb *cb, void *cb_arg);
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off_t blockif_size(struct blockif_ctxt *bc);
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void blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h,
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uint8_t *s);
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int blockif_sectsz(struct blockif_ctxt *bc);
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void blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off);
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int blockif_queuesz(struct blockif_ctxt *bc);
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int blockif_is_ro(struct blockif_ctxt *bc);
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int blockif_candelete(struct blockif_ctxt *bc);
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int blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq);
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int blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq);
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int blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq);
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int blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq);
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int blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq);
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int blockif_close(struct blockif_ctxt *bc);
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#ifdef BHYVE_SNAPSHOT
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void blockif_pause(struct blockif_ctxt *bc);
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void blockif_resume(struct blockif_ctxt *bc);
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int blockif_snapshot_req(struct blockif_req *br,
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struct vm_snapshot_meta *meta);
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int blockif_snapshot(struct blockif_ctxt *bc,
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struct vm_snapshot_meta *meta);
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#endif
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#endif /* _BLOCK_IF_H_ */
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