blob: e24315937c452957fa2315f57c75b92ebf0cc5fb [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
* snapshot.c Ceph snapshot context utility routines (part of libceph)
* Copyright (C) 2013 Inktank Storage, Inc.
#include <linux/types.h>
#include <linux/export.h>
#include <linux/ceph/libceph.h>
* Ceph snapshot contexts are reference counted objects, and the
* returned structure holds a single reference. Acquire additional
* references with ceph_get_snap_context(), and release them with
* ceph_put_snap_context(). When the reference count reaches zero
* the entire structure is freed.
* Create a new ceph snapshot context large enough to hold the
* indicated number of snapshot ids (which can be 0). Caller has
* to fill in snapc->seq and snapc->snaps[0..snap_count-1].
* Returns a null pointer if an error occurs.
struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
gfp_t gfp_flags)
struct ceph_snap_context *snapc;
size_t size;
size = sizeof (struct ceph_snap_context);
size += snap_count * sizeof (snapc->snaps[0]);
snapc = kzalloc(size, gfp_flags);
if (!snapc)
return NULL;
refcount_set(&snapc->nref, 1);
snapc->num_snaps = snap_count;
return snapc;
struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
if (sc)
return sc;
void ceph_put_snap_context(struct ceph_snap_context *sc)
if (!sc)
if (refcount_dec_and_test(&sc->nref)) {
/*printk(" deleting snap_context %p\n", sc);*/