libhammer - Add an overlooked function that releases snaps
[dragonfly.git] / lib / libhammer / snapshot.c
CommitLineData
a77d0377
AHJ
1/*
2 * Copyright (c) 2015 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Antonio Huete <tuxillo@quantumachine.net>
6 * by Matthew Dillon <dillon@backplane.com>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36
37#include <assert.h>
38#include <stdio.h>
39#include <strings.h>
40#include <string.h>
41#include <stdlib.h>
42#include <fcntl.h>
43#include <errno.h>
44#include <unistd.h>
45
46#include "libhammer.h"
47
48int
49libhammer_pfs_get_snapshots(libhammer_fsinfo_t fip, libhammer_pfsinfo_t pip)
50{
51 struct hammer_snapshot_data *snapdata = NULL;
52 struct hammer_ioc_snapshot snap;
53 libhammer_snapinfo_t sip;
54 libhammer_pfsinfo_t pfs0;
55 char *path = NULL;
56 int ret = 0;
57 int fd;
58 u_int i;
59
60 assert(pip != NULL);
61 assert(fip != NULL);
62
63 /*
64 * Still need a path to open so, when not mounted, try
65 * to figure out the PFS path access in order to open(2)
66 * Note that this will fail for slave PFS that were created
67 * with pfs-slave directive since they don't have any transaction
68 * recorded and nlookup can't find them. For those we simply
69 * return the error in the head structure of libhammer_pfsinfo_t
70 * for the caller to handle the situation.
71 */
72 pfs0 = libhammer_get_first_pfs(fip);
73 if (pip->mountedon == NULL)
74 libhammer_pfs_canonical_path(pfs0->mountedon, pip, &path);
75 else
76 path = strdup(pip->mountedon);
77
78 if (path == NULL || (fd = open(path, O_RDONLY)) < 0) {
79 pip->head.error = errno;
80 ret = -1;
81 goto out;
82 }
83
84 bzero(&snap, sizeof(snap));
85
86 /*
87 * Loop while there are snapshots returned from the ioctl(2) call.
88 *
89 * For more information on how the snapshots are returned
90 * to userland please check sys/vfs/hammer/hammer_ioctl.c
91 */
92 do {
93 if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snap) < 0) {
94 pip->head.error = errno;
95 ret = -1;
96 close(fd);
97 goto out;
98 }
99 for (i = 0; i < snap.count; i++) {
100 snapdata = &snap.snaps[i];
101 sip = _libhammer_malloc(sizeof(*sip));
102 sip->tid = snapdata->tid;
103 sip->ts = snapdata->ts;
104 if (strlen(snapdata->label))
105 sprintf(sip->label, "%s", snapdata->label);
106 else
107 sip->label[0] = '\0';
108 TAILQ_INSERT_TAIL(&pip->list_snap, sip, entries);
109 pip->snapcount++;
110 }
111 } while (snap.head.error == 0 && snap.count);
112 close(fd);
113
114out:
115 if (path)
116 free(path);
117
118 return (ret);
119}
cc96d2fe
AHJ
120
121void
122libhammer_pfs_free_snapshots(libhammer_pfsinfo_t pip)
123{
124 struct libhammer_snapinfo *si;
125
126 while(!TAILQ_EMPTY(&pip->list_snap)) {
127 si = TAILQ_FIRST(&pip->list_snap);
128 TAILQ_REMOVE(&pip->list_snap, si, entries);
129 free(si);
130 }
131}