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/*
Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
This file is part of GlusterFS.
This file is licensed to you under your choice of the GNU Lesser
General Public License, version 3 or any later version (LGPLv3 or
later), or the GNU General Public License, version 2 (GPLv2), in all
cases as published by the Free Software Foundation.
*/
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "compat.h"
#include "xlator.h"
#define ONE 1ULL
#define PRESENT_D_OFF_BITS 63
#define BACKEND_D_OFF_BITS 63
#define TOP_BIT (ONE << (PRESENT_D_OFF_BITS - 1))
#define MASK (~0ULL)
#define SHIFT_BITS (max (0, (BACKEND_D_OFF_BITS - PRESENT_D_OFF_BITS + 1)))
#define PRESENT_MASK (MASK >> (64 - PRESENT_D_OFF_BITS))
static uint64_t
bits_for (uint64_t num)
{
uint64_t bits = 0, ctrl = 1;
while (ctrl < num) {
ctrl *= 2;
bits++;
}
return bits;
}
int
gf_deitransform(xlator_t *this,
uint64_t offset)
{
int cnt = 0;
int max = 0;
int max_bits = 0;
uint64_t off_mask = 0;
uint64_t host_mask = 0;
max = glusterfs_get_leaf_count(this->graph);
if (max == 1) {
cnt = 0;
goto out;
}
if (offset & TOP_BIT) {
/* HUGE d_off */
max_bits = bits_for (max);
off_mask = (MASK << max_bits);
host_mask = ~(off_mask);
cnt = offset & host_mask;
} else {
/* small d_off */
cnt = offset % max;
}
out:
return cnt;
}
uint64_t
gf_dirent_orig_offset(xlator_t *this,
uint64_t offset)
{
int max = 0;
int max_bits = 0;
uint64_t off_mask = 0;
uint64_t orig_offset;
max = glusterfs_get_leaf_count(this->graph);
if (max == 1) {
orig_offset = offset;
goto out;
}
if (offset & TOP_BIT) {
/* HUGE d_off */
max_bits = bits_for (max);
off_mask = (MASK << max_bits);
orig_offset = ((offset & ~TOP_BIT) & off_mask) << SHIFT_BITS;
} else {
/* small d_off */
orig_offset = offset / max;
}
out:
return orig_offset;
}
int
gf_itransform (xlator_t *this, uint64_t x, uint64_t *y_p, int client_id)
{
int max = 0;
uint64_t y = 0;
uint64_t hi_mask = 0;
uint64_t off_mask = 0;
int max_bits = 0;
if (x == ((uint64_t) -1)) {
y = (uint64_t) -1;
goto out;
}
if (!x) {
y = 0;
goto out;
}
max = glusterfs_get_leaf_count(this->graph);
if (max == 1) {
y = x;
goto out;
}
max_bits = bits_for (max);
hi_mask = ~(PRESENT_MASK >> (max_bits + 1));
if (x & hi_mask) {
/* HUGE d_off */
off_mask = MASK << max_bits;
y = TOP_BIT | ((x >> SHIFT_BITS) & off_mask) | client_id;
} else {
/* small d_off */
y = ((x * max) + client_id);
}
out:
if (y_p)
*y_p = y;
return 0;
}
gf_dirent_t *
gf_dirent_for_name (const char *name)
{
gf_dirent_t *gf_dirent = NULL;
/* TODO: use mem-pool */
gf_dirent = GF_CALLOC (gf_dirent_size (name), 1,
gf_common_mt_gf_dirent_t);
if (!gf_dirent)
return NULL;
INIT_LIST_HEAD (&gf_dirent->list);
strcpy (gf_dirent->d_name, name);
gf_dirent->d_off = 0;
gf_dirent->d_ino = -1;
gf_dirent->d_type = 0;
gf_dirent->d_len = strlen (name);
return gf_dirent;
}
void
gf_dirent_entry_free (gf_dirent_t *entry)
{
if (!entry)
return;
if (entry->dict)
dict_unref (entry->dict);
if (entry->inode)
inode_unref (entry->inode);
list_del_init (&entry->list);
GF_FREE (entry);
}
void
gf_dirent_free (gf_dirent_t *entries)
{
gf_dirent_t *entry = NULL;
gf_dirent_t *tmp = NULL;
if (!entries)
return;
if (list_empty (&entries->list))
return;
list_for_each_entry_safe (entry, tmp, &entries->list, list) {
gf_dirent_entry_free (entry);
}
}
gf_dirent_t *
entry_copy (gf_dirent_t *source)
{
gf_dirent_t *sink = NULL;
sink = gf_dirent_for_name (source->d_name);
if (!sink)
return NULL;
sink->d_off = source->d_off;
sink->d_ino = source->d_ino;
sink->d_type = source->d_type;
sink->d_stat = source->d_stat;
sink->d_len = source->d_len;
if (source->inode)
sink->inode = inode_ref (source->inode);
if (source->dict)
sink->dict = dict_ref (source->dict);
return sink;
}
void
gf_link_inode_from_dirent (xlator_t *this, inode_t *parent, gf_dirent_t *entry)
{
inode_t *link_inode = NULL;
inode_t *tmp = NULL;
if (!entry->inode)
return;
link_inode = inode_link (entry->inode, parent,
entry->d_name, &entry->d_stat);
if (!link_inode)
return;
inode_lookup (link_inode);
tmp = entry->inode;
entry->inode = link_inode;
inode_unref (tmp);
}
/* TODO: Currently, with this function, we will be breaking the
policy of 1-1 mapping of kernel nlookup refs with our inode_t's
nlookup count.
Need more thoughts before finalizing this function
*/
int
gf_link_inodes_from_dirent (xlator_t *this, inode_t *parent,
gf_dirent_t *entries)
{
gf_dirent_t *entry = NULL;
list_for_each_entry (entry, &entries->list, list) {
gf_link_inode_from_dirent (this, parent, entry);
}
return 0;
}
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