Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * snapshot.c    Ceph snapshot context utility routines (part of libceph)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Copyright (C) 2013 Inktank Storage, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/ceph/libceph.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * Ceph snapshot contexts are reference counted objects, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * returned structure holds a single reference.  Acquire additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * references with ceph_get_snap_context(), and release them with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * ceph_put_snap_context().  When the reference count reaches zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * the entire structure is freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  * Create a new ceph snapshot context large enough to hold the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  * indicated number of snapshot ids (which can be 0).  Caller has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * to fill in snapc->seq and snapc->snaps[0..snap_count-1].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * Returns a null pointer if an error occurs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 						gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	struct ceph_snap_context *snapc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	size_t size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	size = sizeof (struct ceph_snap_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	size += snap_count * sizeof (snapc->snaps[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	snapc = kzalloc(size, gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	if (!snapc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	refcount_set(&snapc->nref, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	snapc->num_snaps = snap_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	return snapc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) EXPORT_SYMBOL(ceph_create_snap_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	if (sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		refcount_inc(&sc->nref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	return sc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) EXPORT_SYMBOL(ceph_get_snap_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) void ceph_put_snap_context(struct ceph_snap_context *sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	if (!sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	if (refcount_dec_and_test(&sc->nref)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		/*printk(" deleting snap_context %p\n", sc);*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 		kfree(sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) EXPORT_SYMBOL(ceph_put_snap_context);