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      1 /*
      2  * bmove.c --- Move blocks around to make way for a particular
      3  * 	filesystem structure.
      4  *
      5  * Copyright (C) 1997 Theodore Ts'o.
      6  *
      7  * %Begin-Header%
      8  * This file may be redistributed under the terms of the GNU Library
      9  * General Public License, version 2.
     10  * %End-Header%
     11  */
     12 
     13 #include <stdio.h>
     14 #include <string.h>
     15 #if HAVE_UNISTD_H
     16 #include <unistd.h>
     17 #endif
     18 #if HAVE_SYS_TYPES_H
     19 #include <sys/types.h>
     20 #endif
     21 #if HAVE_SYS_TIME_H
     22 #include <sys/time.h>
     23 #endif
     24 
     25 #include "ext2_fs.h"
     26 #include "ext2fsP.h"
     27 
     28 struct process_block_struct {
     29 	ext2_ino_t		ino;
     30 	struct ext2_inode *	inode;
     31 	ext2fs_block_bitmap	reserve;
     32 	ext2fs_block_bitmap	alloc_map;
     33 	errcode_t		error;
     34 	char			*buf;
     35 	int			add_dir;
     36 	int			flags;
     37 };
     38 
     39 static int process_block(ext2_filsys fs, blk64_t *block_nr,
     40 			 e2_blkcnt_t blockcnt, blk64_t ref_block,
     41 			 int ref_offset, void *priv_data)
     42 {
     43 	struct process_block_struct *pb;
     44 	errcode_t	retval;
     45 	int		ret;
     46 	blk64_t		block, orig;
     47 
     48 	pb = (struct process_block_struct *) priv_data;
     49 	block = orig = *block_nr;
     50 	ret = 0;
     51 
     52 	/*
     53 	 * Let's see if this is one which we need to relocate
     54 	 */
     55 	if (ext2fs_test_block_bitmap2(pb->reserve, block)) {
     56 		do {
     57 			if (++block >= ext2fs_blocks_count(fs->super))
     58 				block = fs->super->s_first_data_block;
     59 			if (block == orig) {
     60 				pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
     61 				return BLOCK_ABORT;
     62 			}
     63 		} while (ext2fs_test_block_bitmap2(pb->reserve, block) ||
     64 			 ext2fs_test_block_bitmap2(pb->alloc_map, block));
     65 
     66 		retval = io_channel_read_blk64(fs->io, orig, 1, pb->buf);
     67 		if (retval) {
     68 			pb->error = retval;
     69 			return BLOCK_ABORT;
     70 		}
     71 		retval = io_channel_write_blk64(fs->io, block, 1, pb->buf);
     72 		if (retval) {
     73 			pb->error = retval;
     74 			return BLOCK_ABORT;
     75 		}
     76 		*block_nr = block;
     77 		ext2fs_mark_block_bitmap2(pb->alloc_map, block);
     78 		ret = BLOCK_CHANGED;
     79 		if (pb->flags & EXT2_BMOVE_DEBUG)
     80 			printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
     81 			       (unsigned) pb->ino, blockcnt,
     82 			       (unsigned long long) orig,
     83 			       (unsigned long long) block);
     84 	}
     85 	if (pb->add_dir) {
     86 		retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
     87 					       block, blockcnt);
     88 		if (retval) {
     89 			pb->error = retval;
     90 			ret |= BLOCK_ABORT;
     91 		}
     92 	}
     93 	return ret;
     94 }
     95 
     96 errcode_t ext2fs_move_blocks(ext2_filsys fs,
     97 			     ext2fs_block_bitmap reserve,
     98 			     ext2fs_block_bitmap alloc_map,
     99 			     int flags)
    100 {
    101 	ext2_ino_t	ino;
    102 	struct ext2_inode inode;
    103 	errcode_t	retval;
    104 	struct process_block_struct pb;
    105 	ext2_inode_scan	scan;
    106 	char		*block_buf;
    107 
    108 	retval = ext2fs_open_inode_scan(fs, 0, &scan);
    109 	if (retval)
    110 		return retval;
    111 
    112 	pb.reserve = reserve;
    113 	pb.error = 0;
    114 	pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
    115 	pb.flags = flags;
    116 
    117 	retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
    118 	if (retval)
    119 		return retval;
    120 	pb.buf = block_buf + fs->blocksize * 3;
    121 
    122 	/*
    123 	 * If GET_DBLIST is set in the flags field, then we should
    124 	 * gather directory block information while we're doing the
    125 	 * block move.
    126 	 */
    127 	if (flags & EXT2_BMOVE_GET_DBLIST) {
    128 		if (fs->dblist) {
    129 			ext2fs_free_dblist(fs->dblist);
    130 			fs->dblist = NULL;
    131 		}
    132 		retval = ext2fs_init_dblist(fs, 0);
    133 		if (retval)
    134 			return retval;
    135 	}
    136 
    137 	retval = ext2fs_get_next_inode(scan, &ino, &inode);
    138 	if (retval)
    139 		return retval;
    140 
    141 	while (ino) {
    142 		if ((inode.i_links_count == 0) ||
    143 		    !ext2fs_inode_has_valid_blocks2(fs, &inode))
    144 			goto next;
    145 
    146 		pb.ino = ino;
    147 		pb.inode = &inode;
    148 
    149 		pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
    150 			      flags & EXT2_BMOVE_GET_DBLIST);
    151 
    152 		retval = ext2fs_block_iterate3(fs, ino, 0, block_buf,
    153 					       process_block, &pb);
    154 		if (retval)
    155 			return retval;
    156 		if (pb.error)
    157 			return pb.error;
    158 
    159 	next:
    160 		retval = ext2fs_get_next_inode(scan, &ino, &inode);
    161 		if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
    162 			goto next;
    163 	}
    164 	return 0;
    165 }
    166 
    167