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/*
* linux/fs/sysv/balloc.c
*
* minix/bitmap.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext/freelists.c
* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
*
* xenix/alloc.c
* Copyright (C) 1992 Doug Evans
*
* coh/alloc.c
* Copyright (C) 1993 Pascal Haible, Bruno Haible
*
* sysv/balloc.c
* Copyright (C) 1993 Bruno Haible
*
* This file contains code for allocating/freeing blocks.
*/
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sysv_fs.h>
#include <linux/string.h>
#include <linux/locks.h>
/* We don't trust the value of
sb->sv_sbd2->s_tfree = *sb->sv_sb_total_free_blocks
but we nevertheless keep it up to date. */
void sysv_free_block(struct super_block * sb, unsigned int block)
{
struct buffer_head * bh;
char * bh_data;
if (!sb) {
printk("sysv_free_block: trying to free block on nonexistent device\n");
return;
}
if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
printk("sysv_free_block: trying to free block not in datazone\n");
return;
}
lock_super(sb);
if (*sb->sv_sb_flc_count > sb->sv_flc_size) {
printk("sysv_free_block: flc_count > flc_size\n");
unlock_super(sb);
return;
}
/* If the free list head in super-block is full, it is copied
* into this block being freed:
*/
if (*sb->sv_sb_flc_count == sb->sv_flc_size) {
unsigned short * flc_count;
unsigned long * flc_blocks;
bh = sv_getblk(sb, sb->s_dev, block);
if (!bh) {
printk("sysv_free_block: getblk() failed\n");
unlock_super(sb);
return;
}
bh_data = bh->b_data;
switch (sb->sv_type) {
case FSTYPE_XENIX:
flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV4:
flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV2:
flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_COH:
flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
break;
default: panic("sysv_free_block: invalid fs type\n");
}
*flc_count = *sb->sv_sb_flc_count; /* = sb->sv_flc_size */
memcpy(flc_blocks, sb->sv_sb_flc_blocks, *flc_count * sizeof(sysv_zone_t));
mark_buffer_dirty(bh, 1);
mark_buffer_uptodate(bh, 1);
brelse(bh);
*sb->sv_sb_flc_count = 0;
} else
/* If the free list head in super-block is empty, create a new head
* in this block being freed:
*/
if (*sb->sv_sb_flc_count == 0) { /* Applies only to Coherent FS */
bh = sv_getblk(sb, sb->s_dev, block);
if (!bh) {
printk("sysv_free_block: getblk() failed\n");
unlock_super(sb);
return;
}
memset(bh->b_data, 0, sb->sv_block_size);
/* this implies ((struct ..._freelist_chunk *) bh->b_data)->flc_count = 0; */
mark_buffer_dirty(bh, 1);
mark_buffer_uptodate(bh, 1);
brelse(bh);
/* still *sb->sv_sb_flc_count = 0 */
} else {
/* Throw away block's contents */
bh = sv_get_hash_table(sb, sb->s_dev, block);
if (bh)
mark_buffer_clean(bh);
brelse(bh);
}
if (sb->sv_convert)
block = to_coh_ulong(block);
sb->sv_sb_flc_blocks[(*sb->sv_sb_flc_count)++] = block;
if (sb->sv_convert)
*sb->sv_sb_total_free_blocks =
to_coh_ulong(from_coh_ulong(*sb->sv_sb_total_free_blocks) + 1);
else
*sb->sv_sb_total_free_blocks = *sb->sv_sb_total_free_blocks + 1;
mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
sb->s_dirt = 1; /* and needs time stamp */
unlock_super(sb);
}
int sysv_new_block(struct super_block * sb)
{
unsigned int block;
struct buffer_head * bh;
char * bh_data;
if (!sb) {
printk("sysv_new_block: trying to get new block from nonexistent device\n");
return 0;
}
lock_super(sb);
if (*sb->sv_sb_flc_count == 0) { /* Applies only to Coherent FS */
unlock_super(sb);
return 0; /* no blocks available */
}
block = sb->sv_sb_flc_blocks[(*sb->sv_sb_flc_count)-1];
if (sb->sv_convert)
block = from_coh_ulong(block);
if (block == 0) { /* Applies only to Xenix FS, SystemV FS */
unlock_super(sb);
return 0; /* no blocks available */
}
(*sb->sv_sb_flc_count)--;
if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
printk("sysv_new_block: new block %d is not in data zone\n",block);
unlock_super(sb);
return 0;
}
if (*sb->sv_sb_flc_count == 0) { /* the last block continues the free list */
unsigned short * flc_count;
unsigned long * flc_blocks;
if (!(bh = sv_bread(sb, sb->s_dev, block))) {
printk("sysv_new_block: cannot read free-list block\n");
/* retry this same block next time */
(*sb->sv_sb_flc_count)++;
unlock_super(sb);
return 0;
}
bh_data = bh->b_data;
switch (sb->sv_type) {
case FSTYPE_XENIX:
flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV4:
flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV2:
flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_COH:
flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
break;
default: panic("sysv_new_block: invalid fs type\n");
}
if (*flc_count > sb->sv_flc_size) {
printk("sysv_new_block: free-list block with >flc_size entries\n");
brelse(bh);
unlock_super(sb);
return 0;
}
*sb->sv_sb_flc_count = *flc_count;
memcpy(sb->sv_sb_flc_blocks, flc_blocks, *flc_count * sizeof(sysv_zone_t));
brelse(bh);
}
/* Now the free list head in the superblock is valid again. */
bh = sv_getblk(sb, sb->s_dev, block);
if (!bh) {
printk("sysv_new_block: getblk() failed\n");
unlock_super(sb);
return 0;
}
if (bh->b_count != 1) {
printk("sysv_new_block: block already in use\n");
unlock_super(sb);
return 0;
}
memset(bh->b_data, 0, sb->sv_block_size);
mark_buffer_dirty(bh, 1);
mark_buffer_uptodate(bh, 1);
brelse(bh);
if (sb->sv_convert)
*sb->sv_sb_total_free_blocks =
to_coh_ulong(from_coh_ulong(*sb->sv_sb_total_free_blocks) - 1);
else
*sb->sv_sb_total_free_blocks = *sb->sv_sb_total_free_blocks - 1;
mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
sb->s_dirt = 1; /* and needs time stamp */
unlock_super(sb);
return block;
}
unsigned long sysv_count_free_blocks(struct super_block * sb)
{
#if 1 /* test */
int count, old_count;
unsigned int block;
struct buffer_head * bh;
char * bh_data;
int i;
/* this causes a lot of disk traffic ... */
count = 0;
lock_super(sb);
if (*sb->sv_sb_flc_count > 0) {
for (i = *sb->sv_sb_flc_count ; /* i > 0 */ ; ) {
block = sb->sv_sb_flc_blocks[--i];
if (sb->sv_convert)
block = from_coh_ulong(block);
if (block == 0) /* block 0 terminates list */
goto done;
count++;
if (i == 0)
break;
}
/* block = sb->sv_sb_flc_blocks[0], the last block continues the free list */
while (1) {
unsigned short * flc_count;
unsigned long * flc_blocks;
if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
printk("sysv_count_free_blocks: new block %d is not in data zone\n",block);
break;
}
if (!(bh = sv_bread(sb, sb->s_dev, block))) {
printk("sysv_count_free_blocks: cannot read free-list block\n");
break;
}
bh_data = bh->b_data;
switch (sb->sv_type) {
case FSTYPE_XENIX:
flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV4:
flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_SYSV2:
flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
break;
case FSTYPE_COH:
flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
break;
default: panic("sysv_count_free_blocks: invalid fs type\n");
}
if (*flc_count > sb->sv_flc_size) {
printk("sysv_count_free_blocks: free-list block with >flc_size entries\n");
brelse(bh);
break;
}
if (*flc_count == 0) { /* Applies only to Coherent FS */
brelse(bh);
break;
}
for (i = *flc_count ; /* i > 0 */ ; ) {
block = flc_blocks[--i];
if (sb->sv_convert)
block = from_coh_ulong(block);
if (block == 0) /* block 0 terminates list */
break;
count++;
if (i == 0)
break;
}
/* block = flc_blocks[0], the last block continues the free list */
brelse(bh);
if (block == 0) /* Applies only to Xenix FS and SystemV FS */
break;
}
done: ;
}
old_count = *sb->sv_sb_total_free_blocks;
if (sb->sv_convert)
old_count = from_coh_ulong(old_count);
if (count != old_count) {
printk("sysv_count_free_blocks: free block count was %d, correcting to %d\n",old_count,count);
if (!(sb->s_flags & MS_RDONLY)) {
*sb->sv_sb_total_free_blocks = (sb->sv_convert ? to_coh_ulong(count) : count);
mark_buffer_dirty(sb->sv_bh2, 1); /* super-block has been modified */
sb->s_dirt = 1; /* and needs time stamp */
}
}
unlock_super(sb);
return count;
#else
int count;
count = *sb->sv_sb_total_free_blocks;
if (sb->sv_convert)
count = from_coh_ulong(count);
return count;
#endif
}
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