diff options
Diffstat (limited to 'net/ceph')
| -rw-r--r-- | net/ceph/Makefile | 2 | ||||
| -rw-r--r-- | net/ceph/snapshot.c | 78 |
2 files changed, 79 insertions, 1 deletions
diff --git a/net/ceph/Makefile b/net/ceph/Makefile index e87ef435e11..958d9856912 100644 --- a/net/ceph/Makefile +++ b/net/ceph/Makefile @@ -11,5 +11,5 @@ libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \ crypto.o armor.o \ auth_x.o \ ceph_fs.o ceph_strings.o ceph_hash.o \ - pagevec.o + pagevec.o snapshot.o diff --git a/net/ceph/snapshot.c b/net/ceph/snapshot.c new file mode 100644 index 00000000000..154683f5f14 --- /dev/null +++ b/net/ceph/snapshot.c @@ -0,0 +1,78 @@ +/* + * 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); |