/*
 * 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);
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=2fb78e89405f4321b86274a0c24b30896dd50529'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=2fb78e89405f4321b86274a0c24b30896dd50529'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/crypto?id=2fb78e89405f4321b86274a0c24b30896dd50529'>crypto</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529'>drbg.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='2fb78e89405f4321b86274a0c24b30896dd50529'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-27 12:36:39 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-27 12:36:39 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529'>2fb78e89405f4321b86274a0c24b30896dd50529</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=2fb78e89405f4321b86274a0c24b30896dd50529'>4de241e242441b80bd3f0022fc546bb07374571f</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529'>include/crypto/drbg.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/crypto/drbg.h?id=dd3b9f25c867cb2507a45e436d6ede8eb08e7b05'>dd3b9f25c867cb2507a45e436d6ede8eb08e7b05</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529&amp;id2=dd3b9f25c867cb2507a45e436d6ede8eb08e7b05'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/crypto/drbg.h?id=c14024dbb156c8392908aaa822097d27c6af8ec8'>c14024dbb156c8392908aaa822097d27c6af8ec8</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/crypto/drbg.h?id=2fb78e89405f4321b86274a0c24b30896dd50529&amp;id2=c14024dbb156c8392908aaa822097d27c6af8ec8'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'for-linus' of git://git.kernel.dk/linux-block</div><div class='commit-msg'>Pull block fixes from Jens Axboe:
 "A set of fixes for this series. This contains:

   - Set of fixes for the nvme target code

   - A revert of patch from this merge window, causing a regression with
     WRITE_SAME on iSCSI targets at least.

   - A fix for a use-after-free in the new O_DIRECT bdev code.

   - Two fixes for the xen-blkfront driver"

* 'for-linus' of git://git.kernel.dk/linux-block:
  Revert "sd: remove __data_len hack for WRITE SAME"
  nvme-fc: use blk_rq_nr_phys_segments
  nvmet-rdma: Fix missing dma sync to nvme data structures
  nvmet: Call fatal_error from keep-alive timout expiration
  nvmet: cancel fatal error and flush async work before free controller
  nvmet: delete controllers deletion upon subsystem release
  nvmet_fc: correct logic in disconnect queue LS handling
  block: fix use after free in __blkdev_direct_IO
  xen-blkfront: correct maximum segment accounting
  xen-blkfront: feature flags handling adjustments
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=2fb78e89405f4321b86274a0c24b30896dd50529'>Diffstat</a> (limited to 'include/crypto/drbg.h')</div><table summary='diffstat' class='diffstat'>