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Revision db62efbbf883c099d44b0fafe18f8ad8f0396892 authored by Zach Brown on 11 July 2013, 23:19:42 UTC, committed by Chris Mason on 09 August 2013, 23:34:56 UTC 
btrfs: don't loop on large offsets in readdir
 
When btrfs readdir() hits the last entry it sets the readdir offset to a
huge value to stop buggy apps from breaking when the same name is
returned by readdir() with concurrent rename()s.

But unconditionally setting the offset to INT_MAX causes readdir() to
loop returning any entries with offsets past INT_MAX.  It only takes a
few hours of constant file creation and removal to create entries past
INT_MAX.

So let's set the huge offset to LLONG_MAX if the last entry has already
overflowed 32bit loff_t.   Without large offsets behaviour is identical.
With large offsets 64bit apps will work and 32bit apps will be no more
broken than they currently are if they see large offsets.

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
1 parent cfad392
Raw File
ctljack.c 
/*
 * Helper functions for jack-detection kcontrols
 *
 * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/kernel.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>

#define jack_detect_kctl_info	snd_ctl_boolean_mono_info

static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol,
				struct snd_ctl_elem_value *ucontrol)
{
	ucontrol->value.integer.value[0] = kcontrol->private_value;
	return 0;
}

static struct snd_kcontrol_new jack_detect_kctl = {
	/* name is filled later */
	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
	.access = SNDRV_CTL_ELEM_ACCESS_READ,
	.info = jack_detect_kctl_info,
	.get = jack_detect_kctl_get,
};

struct snd_kcontrol *
snd_kctl_jack_new(const char *name, int idx, void *private_data)
{
	struct snd_kcontrol *kctl;
	kctl = snd_ctl_new1(&jack_detect_kctl, private_data);
	if (!kctl)
		return NULL;
	snprintf(kctl->id.name, sizeof(kctl->id.name), "%s Jack", name);
	kctl->id.index = idx;
	kctl->private_value = 0;
	return kctl;
}
EXPORT_SYMBOL_GPL(snd_kctl_jack_new);

void snd_kctl_jack_report(struct snd_card *card,
			  struct snd_kcontrol *kctl, bool status)
{
	if (kctl->private_value == status)
		return;
	kctl->private_value = status;
	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
}
EXPORT_SYMBOL_GPL(snd_kctl_jack_report);
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