1/*
 2 * snapshot.c    Ceph snapshot context utility routines (part of libceph)
 3 *
 4 * Copyright (C) 2013 Inktank Storage, Inc.
 5 *
 6 * This program is free software; you can redistribute it and/or
 7 * modify it under the terms of the GNU General Public License
 8 * version 2 as published by the Free Software Foundation.
 9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA.
19 */
20
21#include <linux/types.h>
22#include <linux/export.h>
23#include <linux/ceph/libceph.h>
24
25/*
26 * Ceph snapshot contexts are reference counted objects, and the
27 * returned structure holds a single reference.  Acquire additional
28 * references with ceph_get_snap_context(), and release them with
29 * ceph_put_snap_context().  When the reference count reaches zero
30 * the entire structure is freed.
31 */
32
33/*
34 * Create a new ceph snapshot context large enough to hold the
35 * indicated number of snapshot ids (which can be 0).  Caller has
36 * to fill in snapc->seq and snapc->snaps[0..snap_count-1].
37 *
38 * Returns a null pointer if an error occurs.
39 */
40struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
41						gfp_t gfp_flags)
42{
43	struct ceph_snap_context *snapc;
44	size_t size;
45
46	size = sizeof (struct ceph_snap_context);
47	size += snap_count * sizeof (snapc->snaps[0]);
48	snapc = kzalloc(size, gfp_flags);
49	if (!snapc)
50		return NULL;
51
52	refcount_set(&snapc->nref, 1);
53	snapc->num_snaps = snap_count;
54
55	return snapc;
56}
57EXPORT_SYMBOL(ceph_create_snap_context);
58
59struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
60{
61	if (sc)
62		refcount_inc(&sc->nref);
63	return sc;
64}
65EXPORT_SYMBOL(ceph_get_snap_context);
66
67void ceph_put_snap_context(struct ceph_snap_context *sc)
68{
69	if (!sc)
70		return;
71	if (refcount_dec_and_test(&sc->nref)) {
72		/*printk(" deleting snap_context %p\n", sc);*/
73		kfree(sc);
74	}
75}
76EXPORT_SYMBOL(ceph_put_snap_context);

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * snapshot.c    Ceph snapshot context utility routines (part of libceph)
 4 *
 5 * Copyright (C) 2013 Inktank Storage, Inc.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 6 */
 7
 8#include <linux/types.h>
 9#include <linux/export.h>
10#include <linux/ceph/libceph.h>
11
12/*
13 * Ceph snapshot contexts are reference counted objects, and the
14 * returned structure holds a single reference.  Acquire additional
15 * references with ceph_get_snap_context(), and release them with
16 * ceph_put_snap_context().  When the reference count reaches zero
17 * the entire structure is freed.
18 */
19
20/*
21 * Create a new ceph snapshot context large enough to hold the
22 * indicated number of snapshot ids (which can be 0).  Caller has
23 * to fill in snapc->seq and snapc->snaps[0..snap_count-1].
24 *
25 * Returns a null pointer if an error occurs.
26 */
27struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
28						gfp_t gfp_flags)
29{
30	struct ceph_snap_context *snapc;
31	size_t size;
32
33	size = sizeof (struct ceph_snap_context);
34	size += snap_count * sizeof (snapc->snaps[0]);
35	snapc = kzalloc(size, gfp_flags);
36	if (!snapc)
37		return NULL;
38
39	refcount_set(&snapc->nref, 1);
40	snapc->num_snaps = snap_count;
41
42	return snapc;
43}
44EXPORT_SYMBOL(ceph_create_snap_context);
45
46struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
47{
48	if (sc)
49		refcount_inc(&sc->nref);
50	return sc;
51}
52EXPORT_SYMBOL(ceph_get_snap_context);
53
54void ceph_put_snap_context(struct ceph_snap_context *sc)
55{
56	if (!sc)
57		return;
58	if (refcount_dec_and_test(&sc->nref)) {
59		/*printk(" deleting snap_context %p\n", sc);*/
60		kfree(sc);
61	}
62}
63EXPORT_SYMBOL(ceph_put_snap_context);