/*
 * linux/fs/befs/endian.h
 *
 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
 *
 * Partially based on similar funtions in the sysv driver.
 */

#ifndef LINUX_BEFS_ENDIAN
#define LINUX_BEFS_ENDIAN

#include <asm/byteorder.h>

static inline u64
fs64_to_cpu(const struct super_block *sb, fs64 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le64_to_cpu((__force __le64)n);
	else
		return be64_to_cpu((__force __be64)n);
}

static inline fs64
cpu_to_fs64(const struct super_block *sb, u64 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs64)cpu_to_le64(n);
	else
		return (__force fs64)cpu_to_be64(n);
}

static inline u32
fs32_to_cpu(const struct super_block *sb, fs32 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le32_to_cpu((__force __le32)n);
	else
		return be32_to_cpu((__force __be32)n);
}

static inline fs32
cpu_to_fs32(const struct super_block *sb, u32 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs32)cpu_to_le32(n);
	else
		return (__force fs32)cpu_to_be32(n);
}

static inline u16
fs16_to_cpu(const struct super_block *sb, fs16 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le16_to_cpu((__force __le16)n);
	else
		return be16_to_cpu((__force __be16)n);
}

static inline fs16
cpu_to_fs16(const struct super_block *sb, u16 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs16)cpu_to_le16(n);
	else
		return (__force fs16)cpu_to_be16(n);
}

/* Composite types below here */

static inline befs_block_run
fsrun_to_cpu(const struct super_block *sb, befs_disk_block_run n)
{
	befs_block_run run;

	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
		run.allocation_group = le32_to_cpu((__force __le32)n.allocation_group);
		run.start = le16_to_cpu((__force __le16)n.start);
		run.len = le16_to_cpu((__force __le16)n.len);
	} else {
		run.allocation_group = be32_to_cpu((__force __be32)n.allocation_group);
		run.start = be16_to_cpu((__force __be16)n.start);
		run.len = be16_to_cpu((__force __be16)n.len);
	}
	return run;
}

static inline befs_disk_block_run
cpu_to_fsrun(const struct super_block *sb, befs_block_run n)
{
	befs_disk_block_run run;

	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
		run.allocation_group = cpu_to_le32(n.allocation_group);
		run.start = cpu_to_le16(n.start);
		run.len = cpu_to_le16(n.len);
	} else {
		run.allocation_group = cpu_to_be32(n.allocation_group);
		run.start = cpu_to_be16(n.start);
		run.len = cpu_to_be16(n.len);
	}
	return run;
}

static inline befs_data_stream
fsds_to_cpu(const struct super_block *sb, const befs_disk_data_stream *n)
{
	befs_data_stream data;
	int i;

	for (i = 0; i < BEFS_NUM_DIRECT_BLOCKS; ++i)
		data.direct[i] = fsrun_to_cpu(sb, n->direct[i]);

	data.max_direct_range = fs64_to_cpu(sb, n->max_direct_range);
	data.indirect = fsrun_to_cpu(sb, n->indirect);
	data.max_indirect_range = fs64_to_cpu(sb, n->max_indirect_range);
	data.double_indirect = fsrun_to_cpu(sb, n->double_indirect);
	data.max_double_indirect_range = fs64_to_cpu(sb,
						     n->
						     max_double_indirect_range);
	data.size = fs64_to_cpu(sb, n->size);

	return data;
}

#endif				//LINUX_BEFS_ENDIAN
mit/tools/arch?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>arch</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/arch/mn10300?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>mn10300</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/tools/arch/mn10300?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/arch/mn10300?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/tools/arch/mn10300?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>tools/arch/mn10300</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/arch/mn10300?h=nds-private-remove&amp;id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/arch/mn10300?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 'tools/arch/mn10300')</div><table summary='diffstat' class='diffstat'>