#ifdef __KERNEL__
# include <linux/slab.h>
# include <linux/crush/crush.h>
#else
# include "crush_compat.h"
# include "crush.h"
#endif

const char *crush_bucket_alg_name(int alg)
{
	switch (alg) {
	case CRUSH_BUCKET_UNIFORM: return "uniform";
	case CRUSH_BUCKET_LIST: return "list";
	case CRUSH_BUCKET_TREE: return "tree";
	case CRUSH_BUCKET_STRAW: return "straw";
	case CRUSH_BUCKET_STRAW2: return "straw2";
	default: return "unknown";
	}
}

/**
 * crush_get_bucket_item_weight - Get weight of an item in given bucket
 * @b: bucket pointer
 * @p: item index in bucket
 */
int crush_get_bucket_item_weight(const struct crush_bucket *b, int p)
{
	if ((__u32)p >= b->size)
		return 0;

	switch (b->alg) {
	case CRUSH_BUCKET_UNIFORM:
		return ((struct crush_bucket_uniform *)b)->item_weight;
	case CRUSH_BUCKET_LIST:
		return ((struct crush_bucket_list *)b)->item_weights[p];
	case CRUSH_BUCKET_TREE:
		return ((struct crush_bucket_tree *)b)->node_weights[crush_calc_tree_node(p)];
	case CRUSH_BUCKET_STRAW:
		return ((struct crush_bucket_straw *)b)->item_weights[p];
	case CRUSH_BUCKET_STRAW2:
		return ((struct crush_bucket_straw2 *)b)->item_weights[p];
	}
	return 0;
}

void crush_destroy_bucket_uniform(struct crush_bucket_uniform *b)
{
	kfree(b->h.perm);
	kfree(b->h.items);
	kfree(b);
}

void crush_destroy_bucket_list(struct crush_bucket_list *b)
{
	kfree(b->item_weights);
	kfree(b->sum_weights);
	kfree(b->h.perm);
	kfree(b->h.items);
	kfree(b);
}

void crush_destroy_bucket_tree(struct crush_bucket_tree *b)
{
	kfree(b->h.perm);
	kfree(b->h.items);
	kfree(b->node_weights);
	kfree(b);
}

void crush_destroy_bucket_straw(struct crush_bucket_straw *b)
{
	kfree(b->straws);
	kfree(b->item_weights);
	kfree(b->h.perm);
	kfree(b->h.items);
	kfree(b);
}

void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b)
{
	kfree(b->item_weights);
	kfree(b->h.perm);
	kfree(b->h.items);
	kfree(b);
}

void crush_destroy_bucket(struct crush_bucket *b)
{
	switch (b->alg) {
	case CRUSH_BUCKET_UNIFORM:
		crush_destroy_bucket_uniform((struct crush_bucket_uniform *)b);
		break;
	case CRUSH_BUCKET_LIST:
		crush_destroy_bucket_list((struct crush_bucket_list *)b);
		break;
	case CRUSH_BUCKET_TREE:
		crush_destroy_bucket_tree((struct crush_bucket_tree *)b);
		break;
	case CRUSH_BUCKET_STRAW:
		crush_destroy_bucket_straw((struct crush_bucket_straw *)b);
		break;
	case CRUSH_BUCKET_STRAW2:
		crush_destroy_bucket_straw2((struct crush_bucket_straw2 *)b);
		break;
	}
}

/**
 * crush_destroy - Destroy a crush_map
 * @map: crush_map pointer
 */
void crush_destroy(struct crush_map *map)
{
	/* buckets */
	if (map->buckets) {
		__s32 b;
		for (b = 0; b < map->max_buckets; b++) {
			if (map->buckets[b] == NULL)
				continue;
			crush_destroy_bucket(map->buckets[b]);
		}
		kfree(map->buckets);
	}

	/* rules */
	if (map->rules) {
		__u32 b;
		for (b = 0; b < map->max_rules; b++)
			crush_destroy_rule(map->rules[b]);
		kfree(map->rules);
	}

#ifndef __KERNEL__
	kfree(map->choose_tries);
#endif
	kfree(map);
}

void crush_destroy_rule(struct crush_rule *rule)
{
	kfree(rule);
}
net-next.git/commit/net?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/wireless?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>wireless</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/.gitignore?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>.gitignore</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='966d2b04e070bc040319aaebfec09e0144dc3341'/><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>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/.gitignore?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/wireless/.gitignore?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/wireless/.gitignore?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>net/wireless/.gitignore</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/.gitignore?h=nds-private-remove&amp;id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/wireless/.gitignore?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().

This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:

__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0

Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.

The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.

Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'net/wireless/.gitignore')</div><table summary='diffstat' class='diffstat'>