mirror of
https://github.com/xen-project/xen.git
synced 2026-10-29 18:50:05 +01:00
Keir Fraser
bd5573a630
Benefits to blktap2 over the old version of blktap: * Isolation from xenstore - Blktap devices are now created directly on the linux dom0 command line, rather than being spawned in response to XenStore events. This is handy for debugging, makes blktap generally easier to work with, and is a step toward a generic user-level block device implementation that is not Xen-specific. * Improved tapdisk infrastructure: simpler request forwarding, new request scheduler, request merging, more efficient use of AIO. * Improved tapdisk error handling and memory management. No allocations on the block data path, IO retry logic to protect guests transient block device failures. This has been tested and is known to work on weird environments such as NFS soft mounts. * Pause and snapshot of live virtual disks (see xmsnap script). * VHD support. The VHD code in this release has been rigorously tested, and represents a very mature implementation of the VHD image format. * No more duplication of mechanism with blkback. The blktap kernel module has changed dramatically from the original blktap. Blkback is now always used to talk to Xen guests, blktap just presents a Linux gendisk that blkback can export. This is done while preserving the zero-copy data path from domU to physical device. These patches deprecate the old blktap code, which can hopefully be removed from the tree completely at some point in the future. Signed-off-by: Jake Wires <jake.wires@citrix.com> Signed-off-by: Dutch Meyer <dmeyer@cs.ubc.ca>
122 lines
3.4 KiB
C
122 lines
3.4 KiB
C
/* qcow-create.c
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*
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* Generates a qcow format disk.
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*
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* (c) 2006 Andrew Warfield and Julian Chesterfield
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/statvfs.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <string.h>
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#include "tapdisk.h"
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#include "qcow.h"
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#if 1
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#define DFPRINTF(_f, _a...) fprintf ( stderr, _f , ## _a )
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#else
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#define DFPRINTF(_f, _a...) ((void)0)
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#endif
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#define MAX_NAME_LEN 1000
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void help(void)
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{
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fprintf(stderr, "Qcow-utils: v1.0.0\n");
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fprintf(stderr,
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"usage: qcow-create [-h help] [-r reserve] <SIZE(MB)> <FILENAME> "
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"[<BACKING_FILENAME>]\n");
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exit(-1);
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}
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int main(int argc, char *argv[])
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{
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int ret = -1, c, backed = 0;
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int sparse = 1;
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uint64_t size;
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char filename[MAX_NAME_LEN], bfilename[MAX_NAME_LEN];
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for(;;) {
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c = getopt(argc, argv, "hr");
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if (c == -1)
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break;
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switch(c) {
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case 'h':
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help();
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exit(0);
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break;
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case 'r':
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sparse = 0;
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break;
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default:
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fprintf(stderr, "Unknown option\n");
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help();
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}
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}
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printf("Optind %d, argc %d\n", optind, argc);
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if ( !(optind == (argc - 2) || optind == (argc - 3)) )
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help();
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size = atoi(argv[optind++]);
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size = size << 20;
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if (snprintf(filename, MAX_NAME_LEN, "%s",argv[optind++]) >=
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MAX_NAME_LEN) {
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fprintf(stderr,"Device name too long\n");
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exit(-1);
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}
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if (optind != argc) {
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/*Backing file argument*/
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backed = 1;
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if (snprintf(bfilename, MAX_NAME_LEN, "%s",argv[optind++]) >=
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MAX_NAME_LEN) {
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fprintf(stderr,"Device name too long\n");
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exit(-1);
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}
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}
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DFPRINTF("Creating file size %"PRIu64", name %s\n",(uint64_t)size, filename);
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if (!backed)
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ret = qcow_create(filename,size,NULL,sparse);
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else
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ret = qcow_create(filename,size,bfilename,sparse);
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if (ret < 0)
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DPRINTF("Unable to create QCOW file\n");
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else
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DPRINTF("QCOW file successfully created\n");
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return 0;
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}
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