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