d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
129eaf7996
freebsd-nq/sys/gnu/ext2fs/ext2_linux_ialloc.c
Marcel Moolenaar cc56683de7 Change of plans: Add ext2_bitops.h with generic and portable 
implementations. Use those on platforms that don't have MD
headers. Remove the ia64 MD header. We're going to use the C
implementation there.

Suggested by: bde
2003-08-25 01:39:47 +00:00

515 lines
14 KiB
C
Raw Blame History

/*
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*
* $FreeBSD$
*/
/*
* linux/fs/ext2/ialloc.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* BSD ufs-inspired inode and directory allocation by
* Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
*/
/*
* The free inodes are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
* when a file system is mounted (see ext2_read_super).
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <gnu/ext2fs/inode.h>
#include <gnu/ext2fs/ext2_mount.h>
#include <gnu/ext2fs/ext2_extern.h>
#include <gnu/ext2fs/ext2_fs.h>
#include <gnu/ext2fs/ext2_fs_sb.h>
#include <gnu/ext2fs/fs.h>
#include <sys/stat.h>
#ifdef __alpha__
#include <gnu/ext2fs/alpha-bitops.h>
#elif __i386__
#include <gnu/ext2fs/i386-bitops.h>
#else
#include <gnu/ext2fs/ext2_bitops.h>
#endif
/* this is supposed to mark a buffer dirty on ready for delayed writing
*/
void mark_buffer_dirty(struct buf *bh)
{
int s;
s = splbio();
bh->b_flags |= B_DIRTY;
splx(s);
}
struct ext2_group_desc * get_group_desc (struct mount * mp,
unsigned int block_group,
struct buffer_head ** bh)
{
struct ext2_sb_info *sb = VFSTOEXT2(mp)->um_e2fs;
unsigned long group_desc;
unsigned long desc;
struct ext2_group_desc * gdp;
if (block_group >= sb->s_groups_count)
panic ("get_group_desc: "
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->s_groups_count);
group_desc = block_group / EXT2_DESC_PER_BLOCK(sb);
desc = block_group % EXT2_DESC_PER_BLOCK(sb);
if (!sb->s_group_desc[group_desc])
panic ( "get_group_desc:"
"Group descriptor not loaded - "
"block_group = %d, group_desc = %lu, desc = %lu",
block_group, group_desc, desc);
gdp = (struct ext2_group_desc *)
sb->s_group_desc[group_desc]->b_data;
if (bh)
*bh = sb->s_group_desc[group_desc];
return gdp + desc;
}
static void read_inode_bitmap (struct mount * mp,
unsigned long block_group,
unsigned int bitmap_nr)
{
struct ext2_sb_info *sb = VFSTOEXT2(mp)->um_e2fs;
struct ext2_group_desc * gdp;
struct buffer_head * bh;
int error;
gdp = get_group_desc (mp, block_group, NULL);
if ((error = bread (VFSTOEXT2(mp)->um_devvp,
fsbtodb(sb, gdp->bg_inode_bitmap),
sb->s_blocksize,
NOCRED, &bh)) != 0)
panic ( "read_inode_bitmap:"
"Cannot read inode bitmap - "
"block_group = %lu, inode_bitmap = %lu",
block_group, (unsigned long) gdp->bg_inode_bitmap);
sb->s_inode_bitmap_number[bitmap_nr] = block_group;
sb->s_inode_bitmap[bitmap_nr] = bh;
LCK_BUF(bh)
}
/*
* load_inode_bitmap loads the inode bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*/
static int load_inode_bitmap (struct mount * mp,
unsigned int block_group)
{
struct ext2_sb_info *sb = VFSTOEXT2(mp)->um_e2fs;
int i, j;
unsigned long inode_bitmap_number;
struct buffer_head * inode_bitmap;
if (block_group >= sb->s_groups_count)
panic ("load_inode_bitmap:"
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->s_groups_count);
if (sb->s_loaded_inode_bitmaps > 0 &&
sb->s_inode_bitmap_number[0] == block_group)
return 0;
if (sb->s_groups_count <= EXT2_MAX_GROUP_LOADED) {
if (sb->s_inode_bitmap[block_group]) {
if (sb->s_inode_bitmap_number[block_group] !=
block_group)
panic ( "load_inode_bitmap:"
"block_group != inode_bitmap_number");
else
return block_group;
} else {
read_inode_bitmap (mp, block_group, block_group);
return block_group;
}
}
for (i = 0; i < sb->s_loaded_inode_bitmaps &&
sb->s_inode_bitmap_number[i] != block_group;
i++)
;
if (i < sb->s_loaded_inode_bitmaps &&
sb->s_inode_bitmap_number[i] == block_group) {
inode_bitmap_number = sb->s_inode_bitmap_number[i];
inode_bitmap = sb->s_inode_bitmap[i];
for (j = i; j > 0; j--) {
sb->s_inode_bitmap_number[j] =
sb->s_inode_bitmap_number[j - 1];
sb->s_inode_bitmap[j] =
sb->s_inode_bitmap[j - 1];
}
sb->s_inode_bitmap_number[0] = inode_bitmap_number;
sb->s_inode_bitmap[0] = inode_bitmap;
} else {
if (sb->s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
sb->s_loaded_inode_bitmaps++;
else
ULCK_BUF(sb->s_inode_bitmap[EXT2_MAX_GROUP_LOADED - 1])
for (j = sb->s_loaded_inode_bitmaps - 1; j > 0; j--) {
sb->s_inode_bitmap_number[j] =
sb->s_inode_bitmap_number[j - 1];
sb->s_inode_bitmap[j] =
sb->s_inode_bitmap[j - 1];
}
read_inode_bitmap (mp, block_group, 0);
}
return 0;
}
void ext2_free_inode (struct inode * inode)
{
struct ext2_sb_info * sb;
struct buffer_head * bh;
struct buffer_head * bh2;
unsigned long block_group;
unsigned long bit;
int bitmap_nr;
struct ext2_group_desc * gdp;
struct ext2_super_block * es;
if (!inode)
return;
if (inode->i_nlink) {
printf ("ext2_free_inode: inode has nlink=%d\n",
inode->i_nlink);
return;
}
ext2_debug ("freeing inode %lu\n", inode->i_number);
sb = inode->i_e2fs;
lock_super (DEVVP(inode));
if (inode->i_number < EXT2_FIRST_INO ||
inode->i_number > sb->s_es->s_inodes_count) {
printf ("free_inode reserved inode or nonexistent inode");
unlock_super (DEVVP(inode));
return;
}
es = sb->s_es;
block_group = (inode->i_number - 1) / EXT2_INODES_PER_GROUP(sb);
bit = (inode->i_number - 1) % EXT2_INODES_PER_GROUP(sb);
bitmap_nr = load_inode_bitmap (ITOV(inode)->v_mount, block_group);
bh = sb->s_inode_bitmap[bitmap_nr];
if (!clear_bit (bit, bh->b_data))
printf ( "ext2_free_inode:"
"bit already cleared for inode %lu",
(unsigned long)inode->i_number);
else {
gdp = get_group_desc (ITOV(inode)->v_mount, block_group, &bh2);
gdp->bg_free_inodes_count++;
if (S_ISDIR(inode->i_mode))
gdp->bg_used_dirs_count--;
mark_buffer_dirty(bh2);
es->s_free_inodes_count++;
}
mark_buffer_dirty(bh);
/*** XXX
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
***/
sb->s_dirt = 1;
unlock_super (DEVVP(inode));
}
#if linux
/*
* This function increments the inode version number
*
* This may be used one day by the NFS server
*/
static void inc_inode_version (struct inode * inode,
struct ext2_group_desc *gdp,
int mode)
{
unsigned long inode_block;
struct buffer_head * bh;
struct ext2_inode * raw_inode;
inode_block = gdp->bg_inode_table + (((inode->i_number - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) /
EXT2_INODES_PER_BLOCK(inode->i_sb));
bh = bread (inode->i_sb->s_dev, inode_block, inode->i_sb->s_blocksize);
if (!bh) {
printf ("inc_inode_version Cannot load inode table block - "
"inode=%lu, inode_block=%lu\n",
inode->i_number, inode_block);
inode->u.ext2_i.i_version = 1;
return;
}
raw_inode = ((struct ext2_inode *) bh->b_data) +
(((inode->i_number - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) %
EXT2_INODES_PER_BLOCK(inode->i_sb));
raw_inode->i_version++;
inode->u.ext2_i.i_version = raw_inode->i_version;
bdwrite (bh);
}
#endif /* linux */
/*
* There are two policies for allocating an inode. If the new inode is
* a directory, then a forward search is made for a block group with both
* free space and a low directory-to-inode ratio; if that fails, then of
* the groups with above-average free space, that group with the fewest
* directories already is chosen.
*
* For other inodes, search forward from the parent directory\'s block
* group to find a free inode.
*/
/*
* this functino has been reduced to the actual 'find the inode number' part
*/
ino_t ext2_new_inode (const struct inode * dir, int mode)
{
struct ext2_sb_info * sb;
struct buffer_head * bh;
struct buffer_head * bh2;
int i, j, avefreei;
int bitmap_nr;
struct ext2_group_desc * gdp;
struct ext2_group_desc * tmp;
struct ext2_super_block * es;
if (!dir)
return 0;
sb = dir->i_e2fs;
lock_super (DEVVP(dir));
es = sb->s_es;
repeat:
gdp = NULL; i=0;
if (S_ISDIR(mode)) {
avefreei = es->s_free_inodes_count /
sb->s_groups_count;
/* I am not yet convinced that this next bit is necessary.
i = dir->u.ext2_i.i_block_group;
for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) {
tmp = get_group_desc (sb, i, &bh2);
if ((tmp->bg_used_dirs_count << 8) <
tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
else
i = ++i % sb->u.ext2_sb.s_groups_count;
}
*/
if (!gdp) {
for (j = 0; j < sb->s_groups_count; j++) {
tmp = get_group_desc(ITOV(dir)->v_mount,j,&bh2);
if (tmp->bg_free_inodes_count &&
tmp->bg_free_inodes_count >= avefreei) {
if (!gdp ||
(tmp->bg_free_blocks_count >
gdp->bg_free_blocks_count)) {
i = j;
gdp = tmp;
}
}
}
}
}
else
{
/*
* Try to place the inode in its parent directory
*/
i = dir->i_block_group;
tmp = get_group_desc (ITOV(dir)->v_mount, i, &bh2);
if (tmp->bg_free_inodes_count)
gdp = tmp;
else
{
/*
* Use a quadratic hash to find a group with a
* free inode
*/
for (j = 1; j < sb->s_groups_count; j <<= 1) {
i += j;
if (i >= sb->s_groups_count)
i -= sb->s_groups_count;
tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
if (tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
}
}
if (!gdp) {
/*
* That failed: try linear search for a free inode
*/
i = dir->i_block_group + 1;
for (j = 2; j < sb->s_groups_count; j++) {
if (++i >= sb->s_groups_count)
i = 0;
tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
if (tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
}
}
}
if (!gdp) {
unlock_super (DEVVP(dir));
return 0;
}
bitmap_nr = load_inode_bitmap (ITOV(dir)->v_mount, i);
bh = sb->s_inode_bitmap[bitmap_nr];
if ((j = find_first_zero_bit ((unsigned long *) bh->b_data,
EXT2_INODES_PER_GROUP(sb))) <
EXT2_INODES_PER_GROUP(sb)) {
if (set_bit (j, bh->b_data)) {
printf ( "ext2_new_inode:"
"bit already set for inode %d", j);
goto repeat;
}
/* Linux now does the following:
mark_buffer_dirty(bh);
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
*/
mark_buffer_dirty(bh);
} else {
if (gdp->bg_free_inodes_count != 0) {
printf ( "ext2_new_inode:"
"Free inodes count corrupted in group %d",
i);
unlock_super (DEVVP(dir));
return 0;
}
goto repeat;
}
j += i * EXT2_INODES_PER_GROUP(sb) + 1;
if (j < EXT2_FIRST_INO || j > es->s_inodes_count) {
printf ( "ext2_new_inode:"
"reserved inode or inode > inodes count - "
"block_group = %d,inode=%d", i, j);
unlock_super (DEVVP(dir));
return 0;
}
gdp->bg_free_inodes_count--;
if (S_ISDIR(mode))
gdp->bg_used_dirs_count++;
mark_buffer_dirty(bh2);
es->s_free_inodes_count--;
/* mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); */
sb->s_dirt = 1;
unlock_super (DEVVP(dir));
return j;
}
#ifdef unused
static unsigned long ext2_count_free_inodes (struct mount * mp)
{
#ifdef EXT2FS_DEBUG
struct ext2_sb_info *sb = VFSTOEXT2(mp)->um_e2fs;
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext2_group_desc * gdp;
int i;
lock_super (VFSTOEXT2(mp)->um_devvp);
es = sb->s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->s_groups_count; i++) {
gdp = get_group_desc (mp, i, NULL);
desc_count += gdp->bg_free_inodes_count;
bitmap_nr = load_inode_bitmap (mp, i);
x = ext2_count_free (sb->s_inode_bitmap[bitmap_nr],
EXT2_INODES_PER_GROUP(sb) / 8);
ext2_debug ("group %d: stored = %d, counted = %lu\n",
i, gdp->bg_free_inodes_count, x);
bitmap_count += x;
}
ext2_debug("stored = %lu, computed = %lu, %lu\n",
es->s_free_inodes_count, desc_count, bitmap_count);
unlock_super (VFSTOEXT2(mp)->um_devvp);
return desc_count;
#else
return VFSTOEXT2(mp)->um_e2fsb->s_free_inodes_count;
#endif
}
#endif /* unused */
#ifdef LATER
void ext2_check_inodes_bitmap (struct mount * mp)
{
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext2_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext2_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
gdp = get_group_desc (sb, i, NULL);
desc_count += gdp->bg_free_inodes_count;
bitmap_nr = load_inode_bitmap (sb, i);
x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
EXT2_INODES_PER_GROUP(sb) / 8);
if (gdp->bg_free_inodes_count != x)
printf ( "ext2_check_inodes_bitmap:"
"Wrong free inodes count in group %d, "
"stored = %d, counted = %lu", i,
gdp->bg_free_inodes_count, x);
bitmap_count += x;
}
if (es->s_free_inodes_count != bitmap_count)
printf ( "ext2_check_inodes_bitmap:"
"Wrong free inodes count in super block, "
"stored = %lu, counted = %lu",
(unsigned long) es->s_free_inodes_count, bitmap_count);
unlock_super (sb);
}
#endif
Reference in New Issue View Git Blame Copy Permalink