1 files changed, 173 insertions, 0 deletions

diff --git a/e2fsprogs/ext2fs/alloc.c b/e2fsprogs/ext2fs/alloc.c
new file mode 100644
index 000000000..7385123b8
--- /dev/null
+++ b/e2fsprogs/ext2fs/alloc.c
@@ -0,0 +1,173 @@
+/*
+ * 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 Public
+ * License.
+ * %End-Header%
+ * 
+ */
+
+#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"
+
+/*
+ * 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      dir_group = 0;
+        ext2_ino_t      i;
+        ext2_ino_t      start_inode;
+
+        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) 
+                dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
+
+        start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
+        if (start_inode < EXT2_FIRST_INODE(fs->super))
+                start_inode = EXT2_FIRST_INODE(fs->super);
+        i = start_inode;
+
+        do {
+                if (!ext2fs_fast_test_inode_bitmap(map, i))
+                        break;
+                i++;
+                if (i > fs->super->s_inodes_count)
+                        i = EXT2_FIRST_INODE(fs->super);
+        } while (i != start_inode);
+        
+        if (ext2fs_test_inode_bitmap(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_block(ext2_filsys fs, blk_t goal,
+                           ext2fs_block_bitmap map, blk_t *ret)
+{
+        blk_t   i;
+
+        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+        if (!map)
+                map = fs->block_map;
+        if (!map)
+                return EXT2_ET_NO_BLOCK_BITMAP;
+        if (!goal || (goal >= fs->super->s_blocks_count))
+                goal = fs->super->s_first_data_block;
+        i = goal;
+        do {
+                if (!ext2fs_fast_test_block_bitmap(map, i)) {
+                        *ret = i;
+                        return 0;
+                }
+                i++;
+                if (i >= fs->super->s_blocks_count)
+                        i = fs->super->s_first_data_block;
+        } while (i != goal);
+        return EXT2_ET_BLOCK_ALLOC_FAIL;
+}
+
+/*
+ * This function zeros out the allocated block, and updates all of the
+ * appropriate filesystem records.
+ */
+errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
+                             char *block_buf, blk_t *ret)
+{
+        errcode_t       retval;
+        blk_t           block;
+        char            *buf = 0;
+
+        if (!block_buf) {
+                retval = ext2fs_get_mem(fs->blocksize, &buf);
+                if (retval)
+                        return retval;
+                block_buf = buf;
+        }
+        memset(block_buf, 0, fs->blocksize);
+
+        if (!fs->block_map) {
+                retval = ext2fs_read_block_bitmap(fs);
+                if (retval)
+                        goto fail;
+        }
+
+        retval = ext2fs_new_block(fs, goal, 0, &block);
+        if (retval)
+                goto fail;
+
+        retval = io_channel_write_blk(fs->io, block, 1, block_buf);
+        if (retval)
+                goto fail;
+        
+        ext2fs_block_alloc_stats(fs, block, +1);
+        *ret = block;
+        return 0;
+
+fail:
+        if (buf)
+                ext2fs_free_mem(&buf);
+        return retval;
+}
+
+errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
+                                 int num, ext2fs_block_bitmap map, blk_t *ret)
+{
+        blk_t   b = start;
+
+        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;
+        do {
+                if (b+num-1 > fs->super->s_blocks_count)
+                        b = fs->super->s_first_data_block;
+                if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
+                        *ret = b;
+                        return 0;
+                }
+                b++;
+        } while (b != finish);
+        return EXT2_ET_BLOCK_ALLOC_FAIL;
+}
+