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/*
* kernel/power/tuxonice_extent.c
*
* Copyright (C) 2003-2015 Nigel Cunningham (nigel at nigelcunningham com au)
*
* Distributed under GPLv2.
*
* These functions encapsulate the manipulation of storage metadata.
*/
#include <linux/suspend.h>
#include "tuxonice_modules.h"
#include "tuxonice_extent.h"
#include "tuxonice_alloc.h"
#include "tuxonice_ui.h"
#include "tuxonice.h"
/**
* toi_get_extent - return a free extent
*
* May fail, returning NULL instead.
**/
static struct hibernate_extent *toi_get_extent(void)
{
return (struct hibernate_extent *) toi_kzalloc(2,
sizeof(struct hibernate_extent), TOI_ATOMIC_GFP);
}
/**
* toi_put_extent_chain - free a chain of extents starting from value 'from'
* @chain: Chain to free.
*
* Note that 'from' is an extent value, and may be part way through an extent.
* In this case, the extent should be truncated (if necessary) and following
* extents freed.
**/
void toi_put_extent_chain_from(struct hibernate_extent_chain *chain, unsigned long from)
{
struct hibernate_extent *this;
this = chain->first;
while (this) {
struct hibernate_extent *next = this->next;
// Delete the whole extent?
if (this->start >= from) {
chain->size -= (this->end - this->start + 1);
if (chain->first == this)
chain->first = next;
if (chain->last_touched == this)
chain->last_touched = NULL;
if (chain->current_extent == this)
chain->current_extent = NULL;
toi_kfree(2, this, sizeof(*this));
chain->num_extents--;
} else if (this->end >= from) {
// Delete part of the extent
chain->size -= (this->end - from + 1);
this->start = from;
}
this = next;
}
}
/**
* toi_put_extent_chain - free a whole chain of extents
* @chain: Chain to free.
**/
void toi_put_extent_chain(struct hibernate_extent_chain *chain)
{
toi_put_extent_chain_from(chain, 0);
}
/**
* toi_add_to_extent_chain - add an extent to an existing chain
* @chain: Chain to which the extend should be added
* @start: Start of the extent (first physical block)
* @end: End of the extent (last physical block)
*
* The chain information is updated if the insertion is successful.
**/
int toi_add_to_extent_chain(struct hibernate_extent_chain *chain,
unsigned long start, unsigned long end)
{
struct hibernate_extent *new_ext = NULL, *cur_ext = NULL;
toi_message(TOI_IO, TOI_VERBOSE, 0,
"Adding extent %lu-%lu to chain %p.\n", start, end, chain);
/* Find the right place in the chain */
if (chain->last_touched && chain->last_touched->start < start)
cur_ext = chain->last_touched;
else if (chain->first && chain->first->start < start)
cur_ext = chain->first;
if (cur_ext) {
while (cur_ext->next && cur_ext->next->start < start)
cur_ext = cur_ext->next;
if (cur_ext->end == (start - 1)) {
struct hibernate_extent *next_ext = cur_ext->next;
cur_ext->end = end;
/* Merge with the following one? */
if (next_ext && cur_ext->end + 1 == next_ext->start) {
cur_ext->end = next_ext->end;
cur_ext->next = next_ext->next;
toi_kfree(2, next_ext, sizeof(*next_ext));
chain->num_extents--;
}
chain->last_touched = cur_ext;
chain->size += (end - start + 1);
return 0;
}
}
new_ext = toi_get_extent();
if (!new_ext) {
printk(KERN_INFO "Error unable to append a new extent to the "
"chain.\n");
return -ENOMEM;
}
chain->num_extents++;
chain->size += (end - start + 1);
new_ext->start = start;
new_ext->end = end;
chain->last_touched = new_ext;
if (cur_ext) {
new_ext->next = cur_ext->next;
cur_ext->next = new_ext;
} else {
if (chain->first)
new_ext->next = chain->first;
chain->first = new_ext;
}
return 0;
}
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