/*
* This clever recursive function handles i_blocks[] as well as
* indirect, double indirect, and triple indirect blocks. It iterates
* over the entries in the i_blocks array or indirect blocks, and for
* each one, will recursively handle any indirect blocks and then
* frees and deallocates the blocks.
*/
static errcode_t ind_punch(ext2_filsys fs, struct ext2_inode *inode,
char *block_buf, blk_t *p, int level,
blk_t start, blk_t count, int max)
{
errcode_t retval;
blk_t b;
int i;
blk64_t offset, incr;
int freed = 0;
#ifdef PUNCH_DEBUG
printf("Entering ind_punch, level %d, start %u, count %u, "
"max %d\n", level, start, count, max);
#endif
incr = 1ULL << ((EXT2_BLOCK_SIZE_BITS(fs->super)-2)*level);
for (i=0, offset=0; i < max; i++, p++, offset += incr) {
if (offset >= start + count)
break;
if (*p == 0 || (offset+incr) <= start)
continue;
b = *p;
if (level > 0) {
blk_t start2;
#ifdef PUNCH_DEBUG
printf("Reading indirect block %u\n", b);
#endif
retval = ext2fs_read_ind_block(fs, b, block_buf);
if (retval)
return retval;
start2 = (start > offset) ? start - offset : 0;
retval = ind_punch(fs, inode, block_buf + fs->blocksize,
(blk_t *) block_buf, level - 1,
start2, count - offset,
fs->blocksize >> 2);
if (retval)
return retval;
retval = ext2fs_write_ind_block(fs, b, block_buf);
if (retval)
return retval;
if (!check_zero_block(block_buf, fs->blocksize))
continue;
}
#ifdef PUNCH_DEBUG
printf("Freeing block %u (offset %llu)\n", b, offset);
#endif
ext2fs_block_alloc_stats(fs, b, -1);
*p = 0;
freed++;
}
/*
* This code assumes that the reserved blocks have already been marked in-use
* during ext2fs_initialize(), so that they are not allocated for other
* uses before we can add them to the resize inode (which has to come
* after the creation of the inode table).
*/
errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
{
errcode_t retval, retval2;
struct ext2_super_block *sb;
struct ext2_inode inode;
__u32 *dindir_buf, *gdt_buf;
unsigned long long apb, inode_size;
/* FIXME-64 - can't deal with extents */
blk_t dindir_blk, rsv_off, gdt_off, gdt_blk;
int dindir_dirty = 0, inode_dirty = 0, sb_blk = 0;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
sb = fs->super;
retval = ext2fs_get_array(2, fs->blocksize, &dindir_buf);
if (retval)
return retval;
gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize);
retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
if (retval)
goto out_free;
/*
* File systems with a blocksize of 1024 and bigalloc have
* sb->s_first_data_block of 0; yet the superblock is still at
* block #1. We compensate for it here.
*/
sb_blk = sb->s_first_data_block;
if (fs->blocksize == 1024 && sb_blk == 0)
sb_blk = 1;
/* Maximum possible file size (we donly use the dindirect blocks) */
apb = EXT2_ADDR_PER_BLOCK(sb);
if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
#ifdef RES_GDT_DEBUG
printf("reading GDT dindir %u\n", dindir_blk);
#endif
retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf);
if (retval)
goto out_inode;
} else {
blk_t goal = sb_blk + fs->desc_blocks +
sb->s_reserved_gdt_blocks + 2 +
fs->inode_blocks_per_group;
retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk);
if (retval)
goto out_free;
inode.i_mode = LINUX_S_IFREG | 0600;
inode.i_links_count = 1;
inode.i_block[EXT2_DIND_BLOCK] = dindir_blk;
ext2fs_iblk_set(fs, &inode, 1);
memset(dindir_buf, 0, fs->blocksize);
#ifdef RES_GDT_DEBUG
printf("allocated GDT dindir %u\n", dindir_blk);
#endif
dindir_dirty = inode_dirty = 1;
inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS;
inode_size *= fs->blocksize;
inode.i_size = inode_size & 0xFFFFFFFF;
inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF;
if(inode.i_size_high) {
sb->s_feature_ro_compat |=
EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
}
inode.i_ctime = fs->now ? fs->now : time(0);
}
for (rsv_off = 0, gdt_off = fs->desc_blocks,
gdt_blk = sb_blk + 1 + fs->desc_blocks;
rsv_off < sb->s_reserved_gdt_blocks;
rsv_off++, gdt_off++, gdt_blk++) {
unsigned int three = 1, five = 5, seven = 7;
unsigned int grp, last = 0;
int gdt_dirty = 0;
gdt_off %= apb;
if (!dindir_buf[gdt_off]) {
/* FIXME XXX XXX
blk_t new_blk;
retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk);
if (retval)
goto out_free;
if (new_blk != gdt_blk) {
// XXX free block
retval = -1; // XXX
}
*/
gdt_dirty = dindir_dirty = inode_dirty = 1;
memset(gdt_buf, 0, fs->blocksize);
dindir_buf[gdt_off] = gdt_blk;
ext2fs_iblk_add_blocks(fs, &inode, 1);
#ifdef RES_GDT_DEBUG
printf("added primary GDT block %u at %u[%u]\n",
gdt_blk, dindir_blk, gdt_off);
#endif
} else if (dindir_buf[gdt_off] == gdt_blk) {
#ifdef RES_GDT_DEBUG
printf("reading primary GDT block %u\n", gdt_blk);
#endif
retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf);
if (retval)
goto out_dindir;
} else {
#ifdef RES_GDT_DEBUG
printf("bad primary GDT %u != %u at %u[%u]\n",
dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off);
#endif
retval = EXT2_ET_RESIZE_INODE_CORRUPT;
goto out_dindir;
}
while ((grp = list_backups(fs, &three, &five, &seven)) <
fs->group_desc_count) {
blk_t expect = gdt_blk + grp * sb->s_blocks_per_group;
if (!gdt_buf[last]) {
#ifdef RES_GDT_DEBUG
printf("added backup GDT %u grp %u@%u[%u]\n",
expect, grp, gdt_blk, last);
#endif
gdt_buf[last] = expect;
ext2fs_iblk_add_blocks(fs, &inode, 1);
gdt_dirty = inode_dirty = 1;
} else if (gdt_buf[last] != expect) {
#ifdef RES_GDT_DEBUG
printf("bad backup GDT %u != %u at %u[%u]\n",
gdt_buf[last], expect, gdt_blk, last);
#endif
retval = EXT2_ET_RESIZE_INODE_CORRUPT;
goto out_dindir;
}
last++;
}
if (gdt_dirty) {
#ifdef RES_GDT_DEBUG
printf("writing primary GDT block %u\n", gdt_blk);
#endif
retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf);
if (retval)
goto out_dindir;
}
}
out_dindir:
if (dindir_dirty) {
retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf);
if (!retval)
retval = retval2;
}
out_inode:
#ifdef RES_GDT_DEBUG
printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks,
inode.i_size);
#endif
if (inode_dirty) {
inode.i_atime = inode.i_mtime = fs->now ? fs->now : time(0);
retval2 = ext2fs_write_new_inode(fs, EXT2_RESIZE_INO, &inode);
if (!retval)
retval = retval2;
}
out_free:
ext2fs_free_mem(&dindir_buf);
return retval;
}