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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-05-15 10:26:50 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-05-15 10:26:50 -0400
commit12e04ffcd93b25dfd726d46338c2ee7d23de556e (patch)
treef91479a62805619168994fd3ee55e3ffa23fc24e /net/ceph/snapshot.c
parent9eff37a8713939f218ab8bf0dc93f1d67af7b8b4 (diff)
parentf722406faae2d073cc1d01063d1123c35425939e (diff)
Merge tag 'v3.10-rc1' into stable/for-linus-3.10
Linux 3.10-rc1 * tag 'v3.10-rc1': (12273 commits) Linux 3.10-rc1 [SCSI] qla2xxx: Update firmware link in Kconfig file. [SCSI] iscsi class, qla4xxx: fix sess/conn refcounting when find fns are used [SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type [SCSI] pm80xx: thermal, sas controller config and error handling update [SCSI] pm80xx: NCQ error handling changes [SCSI] pm80xx: WWN Modification for PM8081/88/89 controllers [SCSI] pm80xx: Changed module name and debug messages update [SCSI] pm80xx: Firmware flash memory free fix, with addition of new memory region for it [SCSI] pm80xx: SPC new firmware changes for device id 0x8081 alone [SCSI] pm80xx: Added SPCv/ve specific hardware functionalities and relevant changes in common files [SCSI] pm80xx: MSI-X implementation for using 64 interrupts [SCSI] pm80xx: Updated common functions common for SPC and SPCv/ve [SCSI] pm80xx: Multiple inbound/outbound queue configuration [SCSI] pm80xx: Added SPCv/ve specific ids, variables and modify for SPC [SCSI] lpfc: fix up Kconfig dependencies [SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd dm cache: set config value dm cache: move config fns dm thin: generate event when metadata threshold passed ...
Diffstat (limited to 'net/ceph/snapshot.c')
-rw-r--r--net/ceph/snapshot.c78
1 files changed, 78 insertions, 0 deletions
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);