Git Repo - linux.git/blame_incremental

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Commit	Line	Data
	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	*/
	27	struct 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	}
	44	EXPORT_SYMBOL(ceph_create_snap_context);
	45
	46	struct 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	}
	52	EXPORT_SYMBOL(ceph_get_snap_context);
	53
	54	void 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	}
	63	EXPORT_SYMBOL(ceph_put_snap_context);