/*
* alloc.c --- allocate new inodes, blocks for ext2fs
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <time.h>
#include <string.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
#define min(a, b) ((a) < (b) ? (a) : (b))
#undef DEBUG
#ifdef DEBUG
# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
#else
# define dbg_printf(f, a...)
#endif
/*
* Clear the uninit block bitmap flag if necessary
*/
void ext2fs_clear_block_uninit(ext2_filsys fs, dgrp_t group)
{
if (group >= fs->group_desc_count ||
!ext2fs_has_group_desc_csum(fs) ||
!(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
return;
/* uninit block bitmaps are now initialized in read_bitmaps() */
ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
ext2fs_group_desc_csum_set(fs, group);
ext2fs_mark_super_dirty(fs);
ext2fs_mark_bb_dirty(fs);
}
/*
* Check for uninit inode bitmaps and deal with them appropriately
*/
static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
dgrp_t group)
{
ext2_ino_t i, ino;
if (group >= fs->group_desc_count ||
!ext2fs_has_group_desc_csum(fs) ||
!(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
return;
ino = (group * fs->super->s_inodes_per_group) + 1;
for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
ext2fs_fast_unmark_inode_bitmap2(map, ino);
ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
/* Mimics what the kernel does */
ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
ext2fs_group_desc_csum_set(fs, group);
ext2fs_mark_ib_dirty(fs);
ext2fs_mark_super_dirty(fs);
}
/*
* Right now, just search forward from the parent directory's block
* group to find the next free inode.
*
* Should have a special policy for directories.
*/
errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
int mode EXT2FS_ATTR((unused)),
ext2fs_inode_bitmap map, ext2_ino_t *ret)
{
ext2_ino_t start_inode = 0;
ext2_ino_t i, ino_in_group, upto, first_zero;
errcode_t retval;
dgrp_t group;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->inode_map;
if (!map)
return EXT2_ET_NO_INODE_BITMAP;
if (dir > 0) {
group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
}
if (start_inode < EXT2_FIRST_INODE(fs->super))
start_inode = EXT2_FIRST_INODE(fs->super);
if (start_inode > fs->super->s_inodes_count)
return EXT2_ET_INODE_ALLOC_FAIL;
i = start_inode;
do {
ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super);
group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super);
check_inode_uninit(fs, map, group);
upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group);
if (i < start_inode && upto >= start_inode)
upto = start_inode - 1;
if (upto > fs->super->s_inodes_count)
upto = fs->super->s_inodes_count;
retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto,
&first_zero);
if (retval == 0) {
i = first_zero;
break;
}
if (retval != ENOENT)
return EXT2_ET_INODE_ALLOC_FAIL;
i = upto + 1;
if (i > fs->super->s_inodes_count)
i = EXT2_FIRST_INODE(fs->super);
} while (i != start_inode);
if (ext2fs_test_inode_bitmap2(map, i))
return EXT2_ET_INODE_ALLOC_FAIL;
*ret = i;
return 0;
}
/*
* Stupid algorithm --- we now just search forward starting from the
* goal. Should put in a smarter one someday....
*/
errcode_t ext2fs_new_block3(ext2_filsys fs, blk64_t goal,
ext2fs_block_bitmap map, blk64_t *ret,
struct blk_alloc_ctx *ctx)
{
errcode_t retval;
blk64_t b = 0;
errcode_t (*gab)(ext2_filsys fs, blk64_t goal, blk64_t *ret);
errcode_t (*gab2)(ext2_filsys, blk64_t, blk64_t *,
struct blk_alloc_ctx *);
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map) {
/*
* In case there are clients out there whose get_alloc_block
* handlers call ext2fs_new_block2 with a NULL block map,
* temporarily swap out the function pointer so that we don't
* end up in an infinite loop.
*/
if (fs->get_alloc_block2) {
gab2 = fs->get_alloc_block2;
fs->get_alloc_block2 = NULL;
retval = gab2(fs, goal, &b, ctx);
fs->get_alloc_block2 = gab2;
goto allocated;
} else if (fs->get_alloc_block) {
gab = fs->get_alloc_block;
fs->get_alloc_block = NULL;
retval = gab(fs, goal, &b);
fs->get_alloc_block = gab;
goto allocated;
}
}
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
goal = fs->super->s_first_data_block;
goal &= ~EXT2FS_CLUSTER_MASK(fs);
retval = ext2fs_find_first_zero_block_bitmap2(map,
goal, ext2fs_blocks_count(fs->super) - 1, &b);
if ((retval == ENOENT) && (goal != fs->super->s_first_data_block))
retval = ext2fs_find_first_zero_block_bitmap2(map,
fs->super->s_first_data_block, goal - 1, &b);
allocated:
if (retval == ENOENT)
return EXT2_ET_BLOCK_ALLOC_FAIL;
if (retval)
return retval;
ext2fs_clear_block_uninit(fs, ext2fs_group_of_blk2(fs, b));
*ret = b;
return 0;
}
errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
ext2fs_block_bitmap map, blk64_t *ret)
{
return ext2fs_new_block3(fs, goal, map, ret, NULL);
}
errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
ext2fs_block_bitmap map, blk_t *ret)
{
errcode_t retval;
blk64_t val;
retval = ext2fs_new_block2(fs, goal, map, &val);
if (!retval)
*ret = (blk_t) val;
return retval;
}
/*
* This function zeros out the allocated block, and updates all of the
* appropriate filesystem records.
*/
errcode_t ext2fs_alloc_block3(ext2_filsys fs, blk64_t goal, char *block_buf,
blk64_t *ret, struct blk_alloc_ctx *ctx)
{
errcode_t retval;
blk64_t block;
if (fs->get_alloc_block2) {
retval = (fs->get_alloc_block2)(fs, goal, &block, ctx);
if (retval)
goto fail;
} else if (fs->get_alloc_block) {
retval = (fs->get_alloc_block)(fs, goal, &block);
if (retval)
goto fail;
} else {
if (!fs->block_map) {
retval = ext2fs_read_block_bitmap(fs);
if (retval)
goto fail;
}
retval = ext2fs_new_block3(fs, goal, 0, &block, ctx);
if (retval)
goto fail;
}
if (block_buf) {
memset(block_buf, 0, fs->blocksize);
retval = io_channel_write_blk64(fs->io, block, 1, block_buf);
} else
retval = ext2fs_zero_blocks2(fs, block, 1, NULL, NULL);
if (retval)
goto fail;
ext2fs_block_alloc_stats2(fs, block, +1);
*ret = block;
fail:
return retval;
}
errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
char *block_buf, blk64_t *ret)
{
return ext2fs_alloc_block3(fs, goal, block_buf, ret, NULL);
}
errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
char *block_buf, blk_t *ret)
{
errcode_t retval;
blk64_t ret64, goal64 = goal;
retval = ext2fs_alloc_block3(fs, goal64, block_buf, &ret64, NULL);
if (!retval)
*ret = (blk_t)ret64;
return retval;
}
errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
int num, ext2fs_block_bitmap map, blk64_t *ret)
{
blk64_t b = start;
int c_ratio;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!b)
b = fs->super->s_first_data_block;
if (!finish)
finish = start;
if (!num)
num = 1;
c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
b &= ~(c_ratio - 1);
finish &= ~(c_ratio -1);
do {
if (b + num - 1 >= ext2fs_blocks_count(fs->super)) {
if (finish > start)
return EXT2_ET_BLOCK_ALLOC_FAIL;
b = fs->super->s_first_data_block;
}
if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
*ret = b;
return 0;
}
b += c_ratio;
} while (b != finish);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
int num, ext2fs_block_bitmap map, blk_t *ret)
{
errcode_t retval;
blk64_t val;
retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val);
if(!retval)
*ret = (blk_t) val;
return retval;
}
void ext2fs_set_alloc_block_callback(ext2_filsys fs,
errcode_t (*func)(ext2_filsys fs,
blk64_t goal,
blk64_t *ret),
errcode_t (**old)(ext2_filsys fs,
blk64_t goal,
blk64_t *ret))
{
if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
return;
if (old)
*old = fs->get_alloc_block;
fs->get_alloc_block = func;
}
blk64_t ext2fs_find_inode_goal(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode, blk64_t lblk)
{
dgrp_t group;
__u8 log_flex;
struct ext2fs_extent extent;
ext2_extent_handle_t handle = NULL;
errcode_t err;
if (inode == NULL || ext2fs_inode_data_blocks2(fs, inode) == 0)
goto no_blocks;
if (inode->i_flags & EXT4_INLINE_DATA_FL)
goto no_blocks;
if (inode->i_flags & EXT4_EXTENTS_FL) {
err = ext2fs_extent_open2(fs, ino, inode, &handle);
if (err)
goto no_blocks;
err = ext2fs_extent_goto2(handle, 0, lblk);
if (err)
goto no_blocks;
err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
if (err)
goto no_blocks;
ext2fs_extent_free(handle);
return extent.e_pblk + (lblk - extent.e_lblk);
}
/* block mapped file; see if block zero is mapped? */
if (inode->i_block[0])
return inode->i_block[0];
no_blocks:
ext2fs_extent_free(handle);
log_flex = fs->super->s_log_groups_per_flex;
group = ext2fs_group_of_ino(fs, ino);
if (log_flex)
group = group & ~((1 << (log_flex)) - 1);
return ext2fs_group_first_block2(fs, group);
}
/*
* Starting at _goal_, scan around the filesystem to find a run of free blocks
* that's at least _len_ blocks long. Possible flags:
* - EXT2_NEWRANGE_EXACT_GOAL: The range of blocks must start at _goal_.
* - EXT2_NEWRANGE_MIN_LENGTH: do not return a allocation shorter than _len_.
* - EXT2_NEWRANGE_ZERO_BLOCKS: Zero blocks pblk to pblk+plen before returning.
*
* The starting block is returned in _pblk_ and the length is returned via
* _plen_. The blocks are not marked in the bitmap; the caller must mark
* however much of the returned run they actually use, hopefully via
* ext2fs_block_alloc_stats_range().
*
* This function can return a range that is longer than what was requested.
*/
errcode_t ext2fs_new_range(ext2_filsys fs, int flags, blk64_t goal,
blk64_t len, ext2fs_block_bitmap map, blk64_t *pblk,
blk64_t *plen)
{
errcode_t retval;
blk64_t start, end, b;
int looped = 0;
blk64_t max_blocks = ext2fs_blocks_count(fs->super);
errcode_t (*nrf)(ext2_filsys fs, int flags, blk64_t goal,
blk64_t len, blk64_t *pblk, blk64_t *plen);
dbg_printf("%s: flags=0x%x goal=%llu len=%llu\n", __func__, flags,
goal, len);
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (len == 0 || (flags & ~EXT2_NEWRANGE_ALL_FLAGS))
return EXT2_ET_INVALID_ARGUMENT;
if (!map && fs->new_range) {
/*
* In case there are clients out there whose new_range
* handlers call ext2fs_new_range with a NULL block map,
* temporarily swap out the function pointer so that we don't
* end up in an infinite loop.
*/
nrf = fs->new_range;
fs->new_range = NULL;
retval = nrf(fs, flags, goal, len, pblk, plen);
fs->new_range = nrf;
if (retval)
return retval;
start = *pblk;
end = *pblk + *plen;
goto allocated;
}
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!goal || goal >= ext2fs_blocks_count(fs->super))
goal = fs->super->s_first_data_block;
start = goal;
while (!looped || start <= goal) {
retval = ext2fs_find_first_zero_block_bitmap2(map, start,
max_blocks - 1,
&start);
if (retval == ENOENT) {
/*
* If there are no free blocks beyond the starting
* point, try scanning the whole filesystem, unless the
* user told us only to allocate from _goal_, or if
* we're already scanning the whole filesystem.
*/
if (flags & EXT2_NEWRANGE_FIXED_GOAL ||
start == fs->super->s_first_data_block)
goto fail;
start = fs->super->s_first_data_block;
continue;
} else if (retval)
goto errout;
if (flags & EXT2_NEWRANGE_FIXED_GOAL && start != goal)
goto fail;
b = min(start + len - 1, max_blocks - 1);
retval = ext2fs_find_first_set_block_bitmap2(map, start, b,
&end);
if (retval == ENOENT)
end = b + 1;
else if (retval)
goto errout;
if (!(flags & EXT2_NEWRANGE_MIN_LENGTH) ||
(end - start) >= len) {
/* Success! */
*pblk = start;
*plen = end - start;
dbg_printf("%s: new_range goal=%llu--%llu "
"blk=%llu--%llu %llu\n",
__func__, goal, goal + len - 1,
*pblk, *pblk + *plen - 1, *plen);
allocated:
for (b = start; b < end;
b += fs->super->s_blocks_per_group)
ext2fs_clear_block_uninit(fs,
ext2fs_group_of_blk2(fs, b));
return 0;
}
if (flags & EXT2_NEWRANGE_FIXED_GOAL)
goto fail;
start = end;
if (start >= max_blocks) {
if (looped)
goto fail;
looped = 1;
start = fs->super->s_first_data_block;
}
}
fail:
retval = EXT2_ET_BLOCK_ALLOC_FAIL;
errout:
return retval;
}
void ext2fs_set_new_range_callback(ext2_filsys fs,
errcode_t (*func)(ext2_filsys fs, int flags, blk64_t goal,
blk64_t len, blk64_t *pblk, blk64_t *plen),
errcode_t (**old)(ext2_filsys fs, int flags, blk64_t goal,
blk64_t len, blk64_t *pblk, blk64_t *plen))
{
if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
return;
if (old)
*old = fs->new_range;
fs->new_range = func;
}
errcode_t ext2fs_alloc_range(ext2_filsys fs, int flags, blk64_t goal,
blk_t len, blk64_t *ret)
{
int newr_flags = EXT2_NEWRANGE_MIN_LENGTH;
errcode_t retval;
blk64_t plen;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (len == 0 || (flags & ~EXT2_ALLOCRANGE_ALL_FLAGS))
return EXT2_ET_INVALID_ARGUMENT;
if (flags & EXT2_ALLOCRANGE_FIXED_GOAL)
newr_flags |= EXT2_NEWRANGE_FIXED_GOAL;
retval = ext2fs_new_range(fs, newr_flags, goal, len, NULL, ret, &plen);
if (retval)
return retval;
if (plen < len)
return EXT2_ET_BLOCK_ALLOC_FAIL;
if (flags & EXT2_ALLOCRANGE_ZERO_BLOCKS) {
retval = ext2fs_zero_blocks2(fs, *ret, len, NULL, NULL);
if (retval)
return retval;
}
ext2fs_block_alloc_stats_range(fs, *ret, len, +1);
return retval;
}