Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4f0dcb10 authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
Browse files

libceph: create source file "net/ceph/snapshot.c" 



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: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent b536f69a

include/linux/ceph/libceph.h

+5 −25
Original line number Diff line number Diff line
@@ -157,31 +157,11 @@ struct ceph_snap_context { 
	u64 snaps[];

};



static inline struct ceph_snap_context *

ceph_get_snap_context(struct ceph_snap_context *sc)

{

	/*

	printk("get_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),

	       atomic_read(&sc->nref)+1);

	*/

	if (sc)

		atomic_inc(&sc->nref);

	return sc;

}



static inline void ceph_put_snap_context(struct ceph_snap_context *sc)

{

	if (!sc)

		return;

	/*

	printk("put_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),

	       atomic_read(&sc->nref)-1);

	*/

	if (atomic_dec_and_test(&sc->nref)) {

		/*printk(" deleting snap_context %p\n", sc);*/

		kfree(sc);

	}

}

extern struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,

					gfp_t gfp_flags);

extern struct ceph_snap_context *ceph_get_snap_context(

					struct ceph_snap_context *sc);

extern void ceph_put_snap_context(struct ceph_snap_context *sc);



/*

 * calculate the number of pages a given length and offset map onto,

net/ceph/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

net/ceph/snapshot.c

0 → 100644
+78 −0
Original line number Diff line number Diff line 
/*

 * 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);