mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-13 07:44:00 +08:00
4f0dcb10cf
This creates a new source file "net/ceph/snapshot.c" to contain utility routines related to ceph snapshot contexts. The main motivation was to define ceph_create_snap_context() as a common way to create these structures, but I've moved the definitions of ceph_get_snap_context() and ceph_put_snap_context() there too. (The benefit of inlining those is very small, and I'd rather keep this collection of functions together.) Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/*
|
|
* snapshot.c Ceph snapshot context utility routines (part of libceph)
|
|
*
|
|
* Copyright (C) 2013 Inktank Storage, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* version 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*/
|
|
|
|
#include <stddef.h>
|
|
|
|
#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;
|
|
|
|
atomic_set(&snapc->nref, 1);
|
|
snapc->num_snaps = snap_count;
|
|
|
|
return snapc;
|
|
}
|
|
EXPORT_SYMBOL(ceph_create_snap_context);
|
|
|
|
struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
|
|
{
|
|
if (sc)
|
|
atomic_inc(&sc->nref);
|
|
return sc;
|
|
}
|
|
EXPORT_SYMBOL(ceph_get_snap_context);
|
|
|
|
void ceph_put_snap_context(struct ceph_snap_context *sc)
|
|
{
|
|
if (!sc)
|
|
return;
|
|
if (atomic_dec_and_test(&sc->nref)) {
|
|
/*printk(" deleting snap_context %p\n", sc);*/
|
|
kfree(sc);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(ceph_put_snap_context);
|