original development tree for Linux kernel GTP module; now long in mainline.
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/*
* direct.c - NILFS direct block pointer.
*
* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Koji Sato <koji@osrg.net>.
*/
#include <linux/errno.h>
#include "nilfs.h"
#include "page.h"
#include "direct.h"
#include "alloc.h"
#include "dat.h"
static inline __le64 *nilfs_direct_dptrs(const struct nilfs_bmap *direct)
{
return (__le64 *)
((struct nilfs_direct_node *)direct->b_u.u_data + 1);
}
static inline __u64
nilfs_direct_get_ptr(const struct nilfs_bmap *direct, __u64 key)
{
return le64_to_cpu(*(nilfs_direct_dptrs(direct) + key));
}
static inline void nilfs_direct_set_ptr(struct nilfs_bmap *direct,
__u64 key, __u64 ptr)
{
*(nilfs_direct_dptrs(direct) + key) = cpu_to_le64(ptr);
}
static int nilfs_direct_lookup(const struct nilfs_bmap *direct,
__u64 key, int level, __u64 *ptrp)
{
__u64 ptr;
if (key > NILFS_DIRECT_KEY_MAX || level != 1)
return -ENOENT;
ptr = nilfs_direct_get_ptr(direct, key);
if (ptr == NILFS_BMAP_INVALID_PTR)
return -ENOENT;
*ptrp = ptr;
return 0;
}
static int nilfs_direct_lookup_contig(const struct nilfs_bmap *direct,
__u64 key, __u64 *ptrp,
unsigned maxblocks)
{
struct inode *dat = NULL;
__u64 ptr, ptr2;
sector_t blocknr;
int ret, cnt;
if (key > NILFS_DIRECT_KEY_MAX)
return -ENOENT;
ptr = nilfs_direct_get_ptr(direct, key);
if (ptr == NILFS_BMAP_INVALID_PTR)
return -ENOENT;
if (NILFS_BMAP_USE_VBN(direct)) {
dat = nilfs_bmap_get_dat(direct);
ret = nilfs_dat_translate(dat, ptr, &blocknr);
if (ret < 0)
return ret;
ptr = blocknr;
}
maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
for (cnt = 1; cnt < maxblocks &&
(ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
NILFS_BMAP_INVALID_PTR;
cnt++) {
if (dat) {
ret = nilfs_dat_translate(dat, ptr2, &blocknr);
if (ret < 0)
return ret;
ptr2 = blocknr;
}
if (ptr2 != ptr + cnt)
break;
}
*ptrp = ptr;
return cnt;
}
static __u64
nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
{
__u64 ptr;
ptr = nilfs_bmap_find_target_seq(direct, key);
if (ptr != NILFS_BMAP_INVALID_PTR)
/* sequential access */
return ptr;
else
/* block group */
return nilfs_bmap_find_target_in_group(direct);
}
static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
{
union nilfs_bmap_ptr_req req;
struct inode *dat = NULL;
struct buffer_head *bh;
int ret;
if (key > NILFS_DIRECT_KEY_MAX)
return -ENOENT;
if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
return -EEXIST;
if (NILFS_BMAP_USE_VBN(bmap)) {
req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
dat = nilfs_bmap_get_dat(bmap);
}
ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
if (!ret) {
/* ptr must be a pointer to a buffer head. */
bh = (struct buffer_head *)((unsigned long)ptr);
set_buffer_nilfs_volatile(bh);
nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
if (!nilfs_bmap_dirty(bmap))
nilfs_bmap_set_dirty(bmap);
if (NILFS_BMAP_USE_VBN(bmap))
nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
nilfs_inode_add_blocks(bmap->b_inode, 1);
}
return ret;
}
static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
{
union nilfs_bmap_ptr_req req;
struct inode *dat;
int ret;
if (key > NILFS_DIRECT_KEY_MAX ||
nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
return -ENOENT;
dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
if (!ret) {
nilfs_bmap_commit_end_ptr(bmap, &req, dat);
nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
nilfs_inode_sub_blocks(bmap->b_inode, 1);
}
return ret;
}
static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
{
__u64 key, lastkey;
lastkey = NILFS_DIRECT_KEY_MAX + 1;
for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
if (nilfs_direct_get_ptr(direct, key) !=
NILFS_BMAP_INVALID_PTR)
lastkey = key;
if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
return -ENOENT;
*keyp = lastkey;
return 0;
}
static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
{
return key > NILFS_DIRECT_KEY_MAX;
}
static int nilfs_direct_gather_data(struct nilfs_bmap *direct,
__u64 *keys, __u64 *ptrs, int nitems)
{
__u64 key;
__u64 ptr;
int n;
if (nitems > NILFS_DIRECT_NBLOCKS)
nitems = NILFS_DIRECT_NBLOCKS;
n = 0;
for (key = 0; key < nitems; key++) {
ptr = nilfs_direct_get_ptr(direct, key);
if (ptr != NILFS_BMAP_INVALID_PTR) {
keys[n] = key;
ptrs[n] = ptr;
n++;
}
}
return n;
}
int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
__u64 key, __u64 *keys, __u64 *ptrs, int n)
{
__le64 *dptrs;
int ret, i, j;
/* no need to allocate any resource for conversion */
/* delete */
ret = bmap->b_ops->bop_delete(bmap, key);
if (ret < 0)
return ret;
/* free resources */
if (bmap->b_ops->bop_clear != NULL)
bmap->b_ops->bop_clear(bmap);
/* convert */
dptrs = nilfs_direct_dptrs(bmap);
for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
if ((j < n) && (i == keys[j])) {
dptrs[i] = (i != key) ?
cpu_to_le64(ptrs[j]) :
NILFS_BMAP_INVALID_PTR;
j++;
} else
dptrs[i] = NILFS_BMAP_INVALID_PTR;
}
nilfs_direct_init(bmap);
return 0;
}
static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
struct buffer_head *bh)
{
struct nilfs_palloc_req oldreq, newreq;
struct inode *dat;
__u64 key;
__u64 ptr;
int ret;
if (!NILFS_BMAP_USE_VBN(bmap))
return 0;
dat = nilfs_bmap_get_dat(bmap);
key = nilfs_bmap_data_get_key(bmap, bh);
ptr = nilfs_direct_get_ptr(bmap, key);
if (!buffer_nilfs_volatile(bh)) {
oldreq.pr_entry_nr = ptr;
newreq.pr_entry_nr = ptr;
ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
if (ret < 0)
return ret;
nilfs_dat_commit_update(dat, &oldreq, &newreq,
bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
set_buffer_nilfs_volatile(bh);
nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
} else
ret = nilfs_dat_mark_dirty(dat, ptr);
return ret;
}
static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
__u64 key, __u64 ptr,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
struct inode *dat = nilfs_bmap_get_dat(direct);
union nilfs_bmap_ptr_req req;
int ret;
req.bpr_ptr = ptr;
ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
if (!ret) {
nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
binfo->bi_v.bi_blkoff = cpu_to_le64(key);
}
return ret;
}
static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
__u64 key, __u64 ptr,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
nilfs_direct_set_ptr(direct, key, blocknr);
binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
binfo->bi_dat.bi_level = 0;
return 0;
}
static int nilfs_direct_assign(struct nilfs_bmap *bmap,
struct buffer_head **bh,
sector_t blocknr,
union nilfs_binfo *binfo)
{
__u64 key;
__u64 ptr;
key = nilfs_bmap_data_get_key(bmap, *bh);
if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
(unsigned long long)key);
return -EINVAL;
}
ptr = nilfs_direct_get_ptr(bmap, key);
if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
(unsigned long long)ptr);
return -EINVAL;
}
return NILFS_BMAP_USE_VBN(bmap) ?
nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
}
static const struct nilfs_bmap_operations nilfs_direct_ops = {
.bop_lookup = nilfs_direct_lookup,
.bop_lookup_contig = nilfs_direct_lookup_contig,
.bop_insert = nilfs_direct_insert,
.bop_delete = nilfs_direct_delete,
.bop_clear = NULL,
.bop_propagate = nilfs_direct_propagate,
.bop_lookup_dirty_buffers = NULL,
.bop_assign = nilfs_direct_assign,
.bop_mark = NULL,
.bop_last_key = nilfs_direct_last_key,
.bop_check_insert = nilfs_direct_check_insert,
.bop_check_delete = NULL,
.bop_gather_data = nilfs_direct_gather_data,
};
int nilfs_direct_init(struct nilfs_bmap *bmap)
{
bmap->b_ops = &nilfs_direct_ops;
return 0;
}