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      1 /*
      2  * online.c --- Do on-line resizing of the ext3 filesystem
      3  *
      4  * Copyright (C) 2006 by Theodore Ts'o
      5  *
      6  * %Begin-Header%
      7  * This file may be redistributed under the terms of the GNU Public
      8  * License.
      9  * %End-Header%
     10  */
     11 
     12 #include "resize2fs.h"
     13 #ifdef HAVE_SYS_IOCTL_H
     14 #include <sys/ioctl.h>
     15 #endif
     16 #include <sys/stat.h>
     17 #include <fcntl.h>
     18 
     19 extern char *program_name;
     20 
     21 errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
     22 			   blk_t *new_size, int flags EXT2FS_ATTR((unused)))
     23 {
     24 #ifdef __linux__
     25 	struct ext2_new_group_input input;
     26 	struct ext4_new_group_input input64;
     27 	struct ext2_super_block *sb = fs->super;
     28 	unsigned long		new_desc_blocks;
     29 	ext2_filsys 		new_fs;
     30 	errcode_t 		retval;
     31 	double			percent;
     32 	dgrp_t			i;
     33 	blk_t			size;
     34 	int			fd, overhead;
     35 	int			use_old_ioctl = 1;
     36 
     37 	printf(_("Filesystem at %s is mounted on %s; "
     38 		 "on-line resizing required\n"), fs->device_name, mtpt);
     39 
     40 	if (*new_size < sb->s_blocks_count) {
     41 		printf(_("On-line shrinking from %u to %u not supported.\n"),
     42 		       sb->s_blocks_count, *new_size);
     43 		exit(1);
     44 	}
     45 
     46 	/*
     47 	 * If the number of descriptor blocks is going to increase,
     48 	 * the on-line resizing inode must be present.
     49 	 */
     50 	new_desc_blocks = ext2fs_div_ceil(
     51 		ext2fs_div_ceil(*new_size -
     52 				fs->super->s_first_data_block,
     53 				EXT2_BLOCKS_PER_GROUP(fs->super)),
     54 		EXT2_DESC_PER_BLOCK(fs->super));
     55 	printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
     56 	       fs->desc_blocks, new_desc_blocks);
     57 	if (!(fs->super->s_feature_compat &
     58 	      EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
     59 	    new_desc_blocks != fs->desc_blocks) {
     60 		com_err(program_name, 0,
     61 			_("Filesystem does not support online resizing"));
     62 		exit(1);
     63 	}
     64 
     65 	fd = open(mtpt, O_RDONLY);
     66 	if (fd < 0) {
     67 		com_err(program_name, errno,
     68 			_("while trying to open mountpoint %s"), mtpt);
     69 		exit(1);
     70 	}
     71 
     72 	size=sb->s_blocks_count;
     73 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
     74 		if (errno == EPERM)
     75 			com_err(program_name, 0,
     76 				_("Permission denied to resize filesystem"));
     77 		else if (errno == ENOTTY)
     78 			com_err(program_name, 0,
     79 			_("Kernel does not support online resizing"));
     80 		else
     81 			com_err(program_name, errno,
     82 			_("While checking for on-line resizing support"));
     83 		exit(1);
     84 	}
     85 
     86 	percent = (sb->s_r_blocks_count * 100.0) / sb->s_blocks_count;
     87 
     88 	retval = ext2fs_read_bitmaps(fs);
     89 	if (retval)
     90 		return retval;
     91 
     92 	retval = ext2fs_dup_handle(fs, &new_fs);
     93 	if (retval)
     94 		return retval;
     95 
     96 	/* The current method of adding one block group at a time to a
     97 	 * mounted filesystem means it is impossible to accomodate the
     98 	 * flex_bg allocation method of placing the metadata together
     99 	 * in a single block group.  For now we "fix" this issue by
    100 	 * using the traditional layout for new block groups, where
    101 	 * each block group is self-contained and contains its own
    102 	 * bitmap blocks and inode tables.  This means we don't get
    103 	 * the layout advantages of flex_bg in the new block groups,
    104 	 * but at least it allows on-line resizing to function.
    105 	 */
    106 	new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
    107 	retval = adjust_fs_info(new_fs, fs, 0, *new_size);
    108 	if (retval)
    109 		return retval;
    110 
    111 	printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
    112 	       fs->device_name, *new_size, fs->blocksize / 1024);
    113 
    114 	size = fs->group_desc_count * sb->s_blocks_per_group +
    115 		sb->s_first_data_block;
    116 	if (size > *new_size)
    117 		size = *new_size;
    118 
    119 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
    120 		com_err(program_name, errno,
    121 			_("While trying to extend the last group"));
    122 		exit(1);
    123 	}
    124 
    125 	for (i = fs->group_desc_count;
    126 	     i < new_fs->group_desc_count; i++) {
    127 
    128 		overhead = (int) (2 + new_fs->inode_blocks_per_group);
    129 
    130 		if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
    131 			overhead += 1 + new_fs->desc_blocks +
    132 				new_fs->super->s_reserved_gdt_blocks;
    133 
    134 		input.group = i;
    135 		input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
    136 		input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
    137 		input.inode_table = new_fs->group_desc[i].bg_inode_table;
    138 		input.blocks_count = sb->s_blocks_per_group;
    139 		if (i == new_fs->group_desc_count-1) {
    140 			input.blocks_count = new_fs->super->s_blocks_count -
    141 				sb->s_first_data_block -
    142 				(i * sb->s_blocks_per_group);
    143 		}
    144 		input.reserved_blocks = (blk_t) (percent * input.blocks_count
    145 						 / 100.0);
    146 
    147 #if 0
    148 		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
    149 		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
    150 		printf("new inode table is at 0x%04x-0x%04x\n",
    151 		       input.inode_table,
    152 		       input.inode_table + new_fs->inode_blocks_per_group-1);
    153 		printf("new group has %u blocks\n", input.blocks_count);
    154 		printf("new group will reserve %d blocks\n",
    155 		       input.reserved_blocks);
    156 		printf("new group has %d free blocks\n",
    157 		       new_fs->group_desc[i].bg_free_blocks_count);
    158 		printf("new group has %d free inodes (%d blocks)\n",
    159 		       new_fs->group_desc[i].bg_free_inodes_count,
    160 		       new_fs->inode_blocks_per_group);
    161 		printf("Adding group #%d\n", input.group);
    162 #endif
    163 
    164 		if (use_old_ioctl &&
    165 		    ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
    166 			continue;
    167 		else
    168 			use_old_ioctl = 0;
    169 
    170 		input64.group = input.group;
    171 		input64.block_bitmap = input.block_bitmap;
    172 		input64.inode_bitmap = input.inode_bitmap;
    173 		input64.inode_table = input.inode_table;
    174 		input64.blocks_count = input.blocks_count;
    175 		input64.reserved_blocks = input.reserved_blocks;
    176 		input64.unused = input.unused;
    177 
    178 		if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
    179 			com_err(program_name, errno,
    180 				_("While trying to add group #%d"),
    181 				input.group);
    182 			exit(1);
    183 		}
    184 	}
    185 
    186 	ext2fs_free(new_fs);
    187 	close(fd);
    188 
    189 	return 0;
    190 #else
    191 	printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
    192 		 "not supported on this system.\n"), fs->device_name, mtpt);
    193 	exit(1);
    194 #endif
    195 }
    196