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![Andi Kleen](/assets/img/avatar_default.png)
No real bugs found, just removed some dead code. Found by gcc 4.6's new warnings. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
1063 lines
33 KiB
C
1063 lines
33 KiB
C
/*
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* linux/fs/ext4/resize.c
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*
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* Support for resizing an ext4 filesystem while it is mounted.
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*
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* Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
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*
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* This could probably be made into a module, because it is not often in use.
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*/
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#define EXT4FS_DEBUG
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include "ext4_jbd2.h"
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#define outside(b, first, last) ((b) < (first) || (b) >= (last))
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#define inside(b, first, last) ((b) >= (first) && (b) < (last))
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static int verify_group_input(struct super_block *sb,
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struct ext4_new_group_data *input)
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{
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct ext4_super_block *es = sbi->s_es;
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ext4_fsblk_t start = ext4_blocks_count(es);
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ext4_fsblk_t end = start + input->blocks_count;
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ext4_group_t group = input->group;
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ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
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unsigned overhead = ext4_bg_has_super(sb, group) ?
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(1 + ext4_bg_num_gdb(sb, group) +
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le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
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ext4_fsblk_t metaend = start + overhead;
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struct buffer_head *bh = NULL;
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ext4_grpblk_t free_blocks_count, offset;
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int err = -EINVAL;
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input->free_blocks_count = free_blocks_count =
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input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
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if (test_opt(sb, DEBUG))
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printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
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"(%d free, %u reserved)\n",
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ext4_bg_has_super(sb, input->group) ? "normal" :
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"no-super", input->group, input->blocks_count,
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free_blocks_count, input->reserved_blocks);
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ext4_get_group_no_and_offset(sb, start, NULL, &offset);
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if (group != sbi->s_groups_count)
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ext4_warning(sb, "Cannot add at group %u (only %u groups)",
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input->group, sbi->s_groups_count);
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else if (offset != 0)
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ext4_warning(sb, "Last group not full");
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else if (input->reserved_blocks > input->blocks_count / 5)
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ext4_warning(sb, "Reserved blocks too high (%u)",
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input->reserved_blocks);
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else if (free_blocks_count < 0)
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ext4_warning(sb, "Bad blocks count %u",
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input->blocks_count);
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else if (!(bh = sb_bread(sb, end - 1)))
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ext4_warning(sb, "Cannot read last block (%llu)",
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end - 1);
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else if (outside(input->block_bitmap, start, end))
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ext4_warning(sb, "Block bitmap not in group (block %llu)",
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(unsigned long long)input->block_bitmap);
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else if (outside(input->inode_bitmap, start, end))
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ext4_warning(sb, "Inode bitmap not in group (block %llu)",
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(unsigned long long)input->inode_bitmap);
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else if (outside(input->inode_table, start, end) ||
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outside(itend - 1, start, end))
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ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
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(unsigned long long)input->inode_table, itend - 1);
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else if (input->inode_bitmap == input->block_bitmap)
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ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
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(unsigned long long)input->block_bitmap);
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else if (inside(input->block_bitmap, input->inode_table, itend))
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ext4_warning(sb, "Block bitmap (%llu) in inode table "
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"(%llu-%llu)",
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(unsigned long long)input->block_bitmap,
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(unsigned long long)input->inode_table, itend - 1);
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else if (inside(input->inode_bitmap, input->inode_table, itend))
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ext4_warning(sb, "Inode bitmap (%llu) in inode table "
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"(%llu-%llu)",
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(unsigned long long)input->inode_bitmap,
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(unsigned long long)input->inode_table, itend - 1);
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else if (inside(input->block_bitmap, start, metaend))
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ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
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(unsigned long long)input->block_bitmap,
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start, metaend - 1);
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else if (inside(input->inode_bitmap, start, metaend))
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ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
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(unsigned long long)input->inode_bitmap,
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start, metaend - 1);
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else if (inside(input->inode_table, start, metaend) ||
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inside(itend - 1, start, metaend))
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ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
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"(%llu-%llu)",
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(unsigned long long)input->inode_table,
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itend - 1, start, metaend - 1);
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else
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err = 0;
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brelse(bh);
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return err;
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}
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static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
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ext4_fsblk_t blk)
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{
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struct buffer_head *bh;
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int err;
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bh = sb_getblk(sb, blk);
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if (!bh)
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return ERR_PTR(-EIO);
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if ((err = ext4_journal_get_write_access(handle, bh))) {
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brelse(bh);
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bh = ERR_PTR(err);
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} else {
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lock_buffer(bh);
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memset(bh->b_data, 0, sb->s_blocksize);
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set_buffer_uptodate(bh);
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unlock_buffer(bh);
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}
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return bh;
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}
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/*
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* If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
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* If that fails, restart the transaction & regain write access for the
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* buffer head which is used for block_bitmap modifications.
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*/
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static int extend_or_restart_transaction(handle_t *handle, int thresh,
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struct buffer_head *bh)
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{
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int err;
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if (ext4_handle_has_enough_credits(handle, thresh))
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return 0;
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err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
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if (err < 0)
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return err;
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if (err) {
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if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
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return err;
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if ((err = ext4_journal_get_write_access(handle, bh)))
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return err;
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}
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return 0;
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}
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/*
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* Set up the block and inode bitmaps, and the inode table for the new group.
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* This doesn't need to be part of the main transaction, since we are only
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* changing blocks outside the actual filesystem. We still do journaling to
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* ensure the recovery is correct in case of a failure just after resize.
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* If any part of this fails, we simply abort the resize.
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*/
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static int setup_new_group_blocks(struct super_block *sb,
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struct ext4_new_group_data *input)
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{
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
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int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
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le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
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unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
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struct buffer_head *bh;
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handle_t *handle;
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ext4_fsblk_t block;
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ext4_grpblk_t bit;
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int i;
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int err = 0, err2;
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/* This transaction may be extended/restarted along the way */
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handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
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if (IS_ERR(handle))
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return PTR_ERR(handle);
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mutex_lock(&sbi->s_resize_lock);
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if (input->group != sbi->s_groups_count) {
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err = -EBUSY;
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goto exit_journal;
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}
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if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
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err = PTR_ERR(bh);
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goto exit_journal;
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}
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if (ext4_bg_has_super(sb, input->group)) {
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ext4_debug("mark backup superblock %#04llx (+0)\n", start);
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ext4_set_bit(0, bh->b_data);
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}
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/* Copy all of the GDT blocks into the backup in this group */
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for (i = 0, bit = 1, block = start + 1;
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i < gdblocks; i++, block++, bit++) {
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struct buffer_head *gdb;
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ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
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if ((err = extend_or_restart_transaction(handle, 1, bh)))
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goto exit_bh;
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gdb = sb_getblk(sb, block);
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if (!gdb) {
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err = -EIO;
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goto exit_bh;
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}
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if ((err = ext4_journal_get_write_access(handle, gdb))) {
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brelse(gdb);
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goto exit_bh;
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}
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lock_buffer(gdb);
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memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
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set_buffer_uptodate(gdb);
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unlock_buffer(gdb);
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ext4_handle_dirty_metadata(handle, NULL, gdb);
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ext4_set_bit(bit, bh->b_data);
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brelse(gdb);
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}
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/* Zero out all of the reserved backup group descriptor table blocks */
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for (i = 0, bit = gdblocks + 1, block = start + bit;
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i < reserved_gdb; i++, block++, bit++) {
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struct buffer_head *gdb;
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ext4_debug("clear reserved block %#04llx (+%d)\n", block, bit);
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if ((err = extend_or_restart_transaction(handle, 1, bh)))
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goto exit_bh;
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if (IS_ERR(gdb = bclean(handle, sb, block))) {
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err = PTR_ERR(gdb);
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goto exit_bh;
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}
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ext4_handle_dirty_metadata(handle, NULL, gdb);
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ext4_set_bit(bit, bh->b_data);
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brelse(gdb);
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}
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ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap,
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input->block_bitmap - start);
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ext4_set_bit(input->block_bitmap - start, bh->b_data);
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ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap,
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input->inode_bitmap - start);
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ext4_set_bit(input->inode_bitmap - start, bh->b_data);
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/* Zero out all of the inode table blocks */
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for (i = 0, block = input->inode_table, bit = block - start;
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i < sbi->s_itb_per_group; i++, bit++, block++) {
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struct buffer_head *it;
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ext4_debug("clear inode block %#04llx (+%d)\n", block, bit);
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if ((err = extend_or_restart_transaction(handle, 1, bh)))
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goto exit_bh;
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if (IS_ERR(it = bclean(handle, sb, block))) {
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err = PTR_ERR(it);
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goto exit_bh;
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}
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ext4_handle_dirty_metadata(handle, NULL, it);
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brelse(it);
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ext4_set_bit(bit, bh->b_data);
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}
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if ((err = extend_or_restart_transaction(handle, 2, bh)))
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goto exit_bh;
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mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8, bh->b_data);
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ext4_handle_dirty_metadata(handle, NULL, bh);
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brelse(bh);
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/* Mark unused entries in inode bitmap used */
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ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
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input->inode_bitmap, input->inode_bitmap - start);
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if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
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err = PTR_ERR(bh);
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goto exit_journal;
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}
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mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
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bh->b_data);
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ext4_handle_dirty_metadata(handle, NULL, bh);
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exit_bh:
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brelse(bh);
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exit_journal:
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mutex_unlock(&sbi->s_resize_lock);
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if ((err2 = ext4_journal_stop(handle)) && !err)
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err = err2;
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return err;
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}
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/*
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* Iterate through the groups which hold BACKUP superblock/GDT copies in an
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* ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
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* calling this for the first time. In a sparse filesystem it will be the
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* sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
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* For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
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*/
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static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
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unsigned *five, unsigned *seven)
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{
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unsigned *min = three;
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int mult = 3;
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unsigned ret;
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if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
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EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
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ret = *min;
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*min += 1;
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return ret;
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}
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if (*five < *min) {
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min = five;
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mult = 5;
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}
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if (*seven < *min) {
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min = seven;
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mult = 7;
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}
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ret = *min;
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*min *= mult;
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return ret;
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}
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/*
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* Check that all of the backup GDT blocks are held in the primary GDT block.
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* It is assumed that they are stored in group order. Returns the number of
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* groups in current filesystem that have BACKUPS, or -ve error code.
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*/
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static int verify_reserved_gdb(struct super_block *sb,
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struct buffer_head *primary)
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{
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const ext4_fsblk_t blk = primary->b_blocknr;
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const ext4_group_t end = EXT4_SB(sb)->s_groups_count;
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unsigned three = 1;
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unsigned five = 5;
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unsigned seven = 7;
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unsigned grp;
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__le32 *p = (__le32 *)primary->b_data;
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int gdbackups = 0;
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while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
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if (le32_to_cpu(*p++) !=
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grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
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ext4_warning(sb, "reserved GDT %llu"
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" missing grp %d (%llu)",
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blk, grp,
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grp *
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(ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
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blk);
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return -EINVAL;
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}
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if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
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return -EFBIG;
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}
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|
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return gdbackups;
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}
|
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|
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/*
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* Called when we need to bring a reserved group descriptor table block into
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* use from the resize inode. The primary copy of the new GDT block currently
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* is an indirect block (under the double indirect block in the resize inode).
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* The new backup GDT blocks will be stored as leaf blocks in this indirect
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* block, in group order. Even though we know all the block numbers we need,
|
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* we check to ensure that the resize inode has actually reserved these blocks.
|
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*
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* Don't need to update the block bitmaps because the blocks are still in use.
|
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*
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* We get all of the error cases out of the way, so that we are sure to not
|
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* fail once we start modifying the data on disk, because JBD has no rollback.
|
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*/
|
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static int add_new_gdb(handle_t *handle, struct inode *inode,
|
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struct ext4_new_group_data *input,
|
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struct buffer_head **primary)
|
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{
|
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struct super_block *sb = inode->i_sb;
|
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struct ext4_super_block *es = EXT4_SB(sb)->s_es;
|
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unsigned long gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
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ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
|
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struct buffer_head **o_group_desc, **n_group_desc;
|
|
struct buffer_head *dind;
|
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int gdbackups;
|
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struct ext4_iloc iloc;
|
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__le32 *data;
|
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int err;
|
|
|
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if (test_opt(sb, DEBUG))
|
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printk(KERN_DEBUG
|
|
"EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
|
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gdb_num);
|
|
|
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/*
|
|
* If we are not using the primary superblock/GDT copy don't resize,
|
|
* because the user tools have no way of handling this. Probably a
|
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* bad time to do it anyways.
|
|
*/
|
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if (EXT4_SB(sb)->s_sbh->b_blocknr !=
|
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le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
|
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ext4_warning(sb, "won't resize using backup superblock at %llu",
|
|
(unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
|
|
return -EPERM;
|
|
}
|
|
|
|
*primary = sb_bread(sb, gdblock);
|
|
if (!*primary)
|
|
return -EIO;
|
|
|
|
if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) {
|
|
err = gdbackups;
|
|
goto exit_bh;
|
|
}
|
|
|
|
data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
|
|
dind = sb_bread(sb, le32_to_cpu(*data));
|
|
if (!dind) {
|
|
err = -EIO;
|
|
goto exit_bh;
|
|
}
|
|
|
|
data = (__le32 *)dind->b_data;
|
|
if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
|
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ext4_warning(sb, "new group %u GDT block %llu not reserved",
|
|
input->group, gdblock);
|
|
err = -EINVAL;
|
|
goto exit_dind;
|
|
}
|
|
|
|
if ((err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh)))
|
|
goto exit_dind;
|
|
|
|
if ((err = ext4_journal_get_write_access(handle, *primary)))
|
|
goto exit_sbh;
|
|
|
|
if ((err = ext4_journal_get_write_access(handle, dind)))
|
|
goto exit_primary;
|
|
|
|
/* ext4_reserve_inode_write() gets a reference on the iloc */
|
|
if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
|
|
goto exit_dindj;
|
|
|
|
n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
|
|
GFP_NOFS);
|
|
if (!n_group_desc) {
|
|
err = -ENOMEM;
|
|
ext4_warning(sb,
|
|
"not enough memory for %lu groups", gdb_num + 1);
|
|
goto exit_inode;
|
|
}
|
|
|
|
/*
|
|
* Finally, we have all of the possible failures behind us...
|
|
*
|
|
* Remove new GDT block from inode double-indirect block and clear out
|
|
* the new GDT block for use (which also "frees" the backup GDT blocks
|
|
* from the reserved inode). We don't need to change the bitmaps for
|
|
* these blocks, because they are marked as in-use from being in the
|
|
* reserved inode, and will become GDT blocks (primary and backup).
|
|
*/
|
|
data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
|
|
ext4_handle_dirty_metadata(handle, NULL, dind);
|
|
brelse(dind);
|
|
inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
|
|
ext4_mark_iloc_dirty(handle, inode, &iloc);
|
|
memset((*primary)->b_data, 0, sb->s_blocksize);
|
|
ext4_handle_dirty_metadata(handle, NULL, *primary);
|
|
|
|
o_group_desc = EXT4_SB(sb)->s_group_desc;
|
|
memcpy(n_group_desc, o_group_desc,
|
|
EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
|
|
n_group_desc[gdb_num] = *primary;
|
|
EXT4_SB(sb)->s_group_desc = n_group_desc;
|
|
EXT4_SB(sb)->s_gdb_count++;
|
|
kfree(o_group_desc);
|
|
|
|
le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
|
|
ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
|
|
|
|
return 0;
|
|
|
|
exit_inode:
|
|
/* ext4_journal_release_buffer(handle, iloc.bh); */
|
|
brelse(iloc.bh);
|
|
exit_dindj:
|
|
/* ext4_journal_release_buffer(handle, dind); */
|
|
exit_primary:
|
|
/* ext4_journal_release_buffer(handle, *primary); */
|
|
exit_sbh:
|
|
/* ext4_journal_release_buffer(handle, *primary); */
|
|
exit_dind:
|
|
brelse(dind);
|
|
exit_bh:
|
|
brelse(*primary);
|
|
|
|
ext4_debug("leaving with error %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Called when we are adding a new group which has a backup copy of each of
|
|
* the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
|
|
* We need to add these reserved backup GDT blocks to the resize inode, so
|
|
* that they are kept for future resizing and not allocated to files.
|
|
*
|
|
* Each reserved backup GDT block will go into a different indirect block.
|
|
* The indirect blocks are actually the primary reserved GDT blocks,
|
|
* so we know in advance what their block numbers are. We only get the
|
|
* double-indirect block to verify it is pointing to the primary reserved
|
|
* GDT blocks so we don't overwrite a data block by accident. The reserved
|
|
* backup GDT blocks are stored in their reserved primary GDT block.
|
|
*/
|
|
static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
|
|
struct ext4_new_group_data *input)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
|
|
struct buffer_head **primary;
|
|
struct buffer_head *dind;
|
|
struct ext4_iloc iloc;
|
|
ext4_fsblk_t blk;
|
|
__le32 *data, *end;
|
|
int gdbackups = 0;
|
|
int res, i;
|
|
int err;
|
|
|
|
primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
|
|
if (!primary)
|
|
return -ENOMEM;
|
|
|
|
data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
|
|
dind = sb_bread(sb, le32_to_cpu(*data));
|
|
if (!dind) {
|
|
err = -EIO;
|
|
goto exit_free;
|
|
}
|
|
|
|
blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
|
|
data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
|
|
EXT4_ADDR_PER_BLOCK(sb));
|
|
end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
|
|
|
|
/* Get each reserved primary GDT block and verify it holds backups */
|
|
for (res = 0; res < reserved_gdb; res++, blk++) {
|
|
if (le32_to_cpu(*data) != blk) {
|
|
ext4_warning(sb, "reserved block %llu"
|
|
" not at offset %ld",
|
|
blk,
|
|
(long)(data - (__le32 *)dind->b_data));
|
|
err = -EINVAL;
|
|
goto exit_bh;
|
|
}
|
|
primary[res] = sb_bread(sb, blk);
|
|
if (!primary[res]) {
|
|
err = -EIO;
|
|
goto exit_bh;
|
|
}
|
|
if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
|
|
brelse(primary[res]);
|
|
err = gdbackups;
|
|
goto exit_bh;
|
|
}
|
|
if (++data >= end)
|
|
data = (__le32 *)dind->b_data;
|
|
}
|
|
|
|
for (i = 0; i < reserved_gdb; i++) {
|
|
if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
|
|
/*
|
|
int j;
|
|
for (j = 0; j < i; j++)
|
|
ext4_journal_release_buffer(handle, primary[j]);
|
|
*/
|
|
goto exit_bh;
|
|
}
|
|
}
|
|
|
|
if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
|
|
goto exit_bh;
|
|
|
|
/*
|
|
* Finally we can add each of the reserved backup GDT blocks from
|
|
* the new group to its reserved primary GDT block.
|
|
*/
|
|
blk = input->group * EXT4_BLOCKS_PER_GROUP(sb);
|
|
for (i = 0; i < reserved_gdb; i++) {
|
|
int err2;
|
|
data = (__le32 *)primary[i]->b_data;
|
|
/* printk("reserving backup %lu[%u] = %lu\n",
|
|
primary[i]->b_blocknr, gdbackups,
|
|
blk + primary[i]->b_blocknr); */
|
|
data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
|
|
err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
|
|
if (!err)
|
|
err = err2;
|
|
}
|
|
inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
|
|
ext4_mark_iloc_dirty(handle, inode, &iloc);
|
|
|
|
exit_bh:
|
|
while (--res >= 0)
|
|
brelse(primary[res]);
|
|
brelse(dind);
|
|
|
|
exit_free:
|
|
kfree(primary);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Update the backup copies of the ext4 metadata. These don't need to be part
|
|
* of the main resize transaction, because e2fsck will re-write them if there
|
|
* is a problem (basically only OOM will cause a problem). However, we
|
|
* _should_ update the backups if possible, in case the primary gets trashed
|
|
* for some reason and we need to run e2fsck from a backup superblock. The
|
|
* important part is that the new block and inode counts are in the backup
|
|
* superblocks, and the location of the new group metadata in the GDT backups.
|
|
*
|
|
* We do not need take the s_resize_lock for this, because these
|
|
* blocks are not otherwise touched by the filesystem code when it is
|
|
* mounted. We don't need to worry about last changing from
|
|
* sbi->s_groups_count, because the worst that can happen is that we
|
|
* do not copy the full number of backups at this time. The resize
|
|
* which changed s_groups_count will backup again.
|
|
*/
|
|
static void update_backups(struct super_block *sb,
|
|
int blk_off, char *data, int size)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
const ext4_group_t last = sbi->s_groups_count;
|
|
const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
|
|
unsigned three = 1;
|
|
unsigned five = 5;
|
|
unsigned seven = 7;
|
|
ext4_group_t group;
|
|
int rest = sb->s_blocksize - size;
|
|
handle_t *handle;
|
|
int err = 0, err2;
|
|
|
|
handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
|
|
if (IS_ERR(handle)) {
|
|
group = 1;
|
|
err = PTR_ERR(handle);
|
|
goto exit_err;
|
|
}
|
|
|
|
while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
|
|
struct buffer_head *bh;
|
|
|
|
/* Out of journal space, and can't get more - abort - so sad */
|
|
if (ext4_handle_valid(handle) &&
|
|
handle->h_buffer_credits == 0 &&
|
|
ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
|
|
(err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
|
|
break;
|
|
|
|
bh = sb_getblk(sb, group * bpg + blk_off);
|
|
if (!bh) {
|
|
err = -EIO;
|
|
break;
|
|
}
|
|
ext4_debug("update metadata backup %#04lx\n",
|
|
(unsigned long)bh->b_blocknr);
|
|
if ((err = ext4_journal_get_write_access(handle, bh)))
|
|
break;
|
|
lock_buffer(bh);
|
|
memcpy(bh->b_data, data, size);
|
|
if (rest)
|
|
memset(bh->b_data + size, 0, rest);
|
|
set_buffer_uptodate(bh);
|
|
unlock_buffer(bh);
|
|
ext4_handle_dirty_metadata(handle, NULL, bh);
|
|
brelse(bh);
|
|
}
|
|
if ((err2 = ext4_journal_stop(handle)) && !err)
|
|
err = err2;
|
|
|
|
/*
|
|
* Ugh! Need to have e2fsck write the backup copies. It is too
|
|
* late to revert the resize, we shouldn't fail just because of
|
|
* the backup copies (they are only needed in case of corruption).
|
|
*
|
|
* However, if we got here we have a journal problem too, so we
|
|
* can't really start a transaction to mark the superblock.
|
|
* Chicken out and just set the flag on the hope it will be written
|
|
* to disk, and if not - we will simply wait until next fsck.
|
|
*/
|
|
exit_err:
|
|
if (err) {
|
|
ext4_warning(sb, "can't update backup for group %u (err %d), "
|
|
"forcing fsck on next reboot", group, err);
|
|
sbi->s_mount_state &= ~EXT4_VALID_FS;
|
|
sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
|
|
mark_buffer_dirty(sbi->s_sbh);
|
|
}
|
|
}
|
|
|
|
/* Add group descriptor data to an existing or new group descriptor block.
|
|
* Ensure we handle all possible error conditions _before_ we start modifying
|
|
* the filesystem, because we cannot abort the transaction and not have it
|
|
* write the data to disk.
|
|
*
|
|
* If we are on a GDT block boundary, we need to get the reserved GDT block.
|
|
* Otherwise, we may need to add backup GDT blocks for a sparse group.
|
|
*
|
|
* We only need to hold the superblock lock while we are actually adding
|
|
* in the new group's counts to the superblock. Prior to that we have
|
|
* not really "added" the group at all. We re-check that we are still
|
|
* adding in the last group in case things have changed since verifying.
|
|
*/
|
|
int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct ext4_super_block *es = sbi->s_es;
|
|
int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
|
|
le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
|
|
struct buffer_head *primary = NULL;
|
|
struct ext4_group_desc *gdp;
|
|
struct inode *inode = NULL;
|
|
handle_t *handle;
|
|
int gdb_off, gdb_num;
|
|
int err, err2;
|
|
|
|
gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
|
|
gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
|
|
|
|
if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
|
|
EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
|
|
ext4_warning(sb, "Can't resize non-sparse filesystem further");
|
|
return -EPERM;
|
|
}
|
|
|
|
if (ext4_blocks_count(es) + input->blocks_count <
|
|
ext4_blocks_count(es)) {
|
|
ext4_warning(sb, "blocks_count overflow");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
|
|
le32_to_cpu(es->s_inodes_count)) {
|
|
ext4_warning(sb, "inodes_count overflow");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (reserved_gdb || gdb_off == 0) {
|
|
if (!EXT4_HAS_COMPAT_FEATURE(sb,
|
|
EXT4_FEATURE_COMPAT_RESIZE_INODE)
|
|
|| !le16_to_cpu(es->s_reserved_gdt_blocks)) {
|
|
ext4_warning(sb,
|
|
"No reserved GDT blocks, can't resize");
|
|
return -EPERM;
|
|
}
|
|
inode = ext4_iget(sb, EXT4_RESIZE_INO);
|
|
if (IS_ERR(inode)) {
|
|
ext4_warning(sb, "Error opening resize inode");
|
|
return PTR_ERR(inode);
|
|
}
|
|
}
|
|
|
|
|
|
if ((err = verify_group_input(sb, input)))
|
|
goto exit_put;
|
|
|
|
if ((err = setup_new_group_blocks(sb, input)))
|
|
goto exit_put;
|
|
|
|
/*
|
|
* We will always be modifying at least the superblock and a GDT
|
|
* block. If we are adding a group past the last current GDT block,
|
|
* we will also modify the inode and the dindirect block. If we
|
|
* are adding a group with superblock/GDT backups we will also
|
|
* modify each of the reserved GDT dindirect blocks.
|
|
*/
|
|
handle = ext4_journal_start_sb(sb,
|
|
ext4_bg_has_super(sb, input->group) ?
|
|
3 + reserved_gdb : 4);
|
|
if (IS_ERR(handle)) {
|
|
err = PTR_ERR(handle);
|
|
goto exit_put;
|
|
}
|
|
|
|
mutex_lock(&sbi->s_resize_lock);
|
|
if (input->group != sbi->s_groups_count) {
|
|
ext4_warning(sb, "multiple resizers run on filesystem!");
|
|
err = -EBUSY;
|
|
goto exit_journal;
|
|
}
|
|
|
|
if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
|
|
goto exit_journal;
|
|
|
|
/*
|
|
* We will only either add reserved group blocks to a backup group
|
|
* or remove reserved blocks for the first group in a new group block.
|
|
* Doing both would be mean more complex code, and sane people don't
|
|
* use non-sparse filesystems anymore. This is already checked above.
|
|
*/
|
|
if (gdb_off) {
|
|
primary = sbi->s_group_desc[gdb_num];
|
|
if ((err = ext4_journal_get_write_access(handle, primary)))
|
|
goto exit_journal;
|
|
|
|
if (reserved_gdb && ext4_bg_num_gdb(sb, input->group) &&
|
|
(err = reserve_backup_gdb(handle, inode, input)))
|
|
goto exit_journal;
|
|
} else if ((err = add_new_gdb(handle, inode, input, &primary)))
|
|
goto exit_journal;
|
|
|
|
/*
|
|
* OK, now we've set up the new group. Time to make it active.
|
|
*
|
|
* We do not lock all allocations via s_resize_lock
|
|
* so we have to be safe wrt. concurrent accesses the group
|
|
* data. So we need to be careful to set all of the relevant
|
|
* group descriptor data etc. *before* we enable the group.
|
|
*
|
|
* The key field here is sbi->s_groups_count: as long as
|
|
* that retains its old value, nobody is going to access the new
|
|
* group.
|
|
*
|
|
* So first we update all the descriptor metadata for the new
|
|
* group; then we update the total disk blocks count; then we
|
|
* update the groups count to enable the group; then finally we
|
|
* update the free space counts so that the system can start
|
|
* using the new disk blocks.
|
|
*/
|
|
|
|
/* Update group descriptor block for new group */
|
|
gdp = (struct ext4_group_desc *)((char *)primary->b_data +
|
|
gdb_off * EXT4_DESC_SIZE(sb));
|
|
|
|
memset(gdp, 0, EXT4_DESC_SIZE(sb));
|
|
ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
|
|
ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
|
|
ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
|
|
ext4_free_blks_set(sb, gdp, input->free_blocks_count);
|
|
ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
|
|
gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED);
|
|
gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
|
|
|
|
/*
|
|
* We can allocate memory for mb_alloc based on the new group
|
|
* descriptor
|
|
*/
|
|
err = ext4_mb_add_groupinfo(sb, input->group, gdp);
|
|
if (err)
|
|
goto exit_journal;
|
|
|
|
/*
|
|
* Make the new blocks and inodes valid next. We do this before
|
|
* increasing the group count so that once the group is enabled,
|
|
* all of its blocks and inodes are already valid.
|
|
*
|
|
* We always allocate group-by-group, then block-by-block or
|
|
* inode-by-inode within a group, so enabling these
|
|
* blocks/inodes before the group is live won't actually let us
|
|
* allocate the new space yet.
|
|
*/
|
|
ext4_blocks_count_set(es, ext4_blocks_count(es) +
|
|
input->blocks_count);
|
|
le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb));
|
|
|
|
/*
|
|
* We need to protect s_groups_count against other CPUs seeing
|
|
* inconsistent state in the superblock.
|
|
*
|
|
* The precise rules we use are:
|
|
*
|
|
* * Writers of s_groups_count *must* hold s_resize_lock
|
|
* AND
|
|
* * Writers must perform a smp_wmb() after updating all dependent
|
|
* data and before modifying the groups count
|
|
*
|
|
* * Readers must hold s_resize_lock over the access
|
|
* OR
|
|
* * Readers must perform an smp_rmb() after reading the groups count
|
|
* and before reading any dependent data.
|
|
*
|
|
* NB. These rules can be relaxed when checking the group count
|
|
* while freeing data, as we can only allocate from a block
|
|
* group after serialising against the group count, and we can
|
|
* only then free after serialising in turn against that
|
|
* allocation.
|
|
*/
|
|
smp_wmb();
|
|
|
|
/* Update the global fs size fields */
|
|
sbi->s_groups_count++;
|
|
|
|
ext4_handle_dirty_metadata(handle, NULL, primary);
|
|
|
|
/* Update the reserved block counts only once the new group is
|
|
* active. */
|
|
ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
|
|
input->reserved_blocks);
|
|
|
|
/* Update the free space counts */
|
|
percpu_counter_add(&sbi->s_freeblocks_counter,
|
|
input->free_blocks_count);
|
|
percpu_counter_add(&sbi->s_freeinodes_counter,
|
|
EXT4_INODES_PER_GROUP(sb));
|
|
|
|
if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
|
|
sbi->s_log_groups_per_flex) {
|
|
ext4_group_t flex_group;
|
|
flex_group = ext4_flex_group(sbi, input->group);
|
|
atomic_add(input->free_blocks_count,
|
|
&sbi->s_flex_groups[flex_group].free_blocks);
|
|
atomic_add(EXT4_INODES_PER_GROUP(sb),
|
|
&sbi->s_flex_groups[flex_group].free_inodes);
|
|
}
|
|
|
|
ext4_handle_dirty_super(handle, sb);
|
|
|
|
exit_journal:
|
|
mutex_unlock(&sbi->s_resize_lock);
|
|
if ((err2 = ext4_journal_stop(handle)) && !err)
|
|
err = err2;
|
|
if (!err) {
|
|
update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
|
|
sizeof(struct ext4_super_block));
|
|
update_backups(sb, primary->b_blocknr, primary->b_data,
|
|
primary->b_size);
|
|
}
|
|
exit_put:
|
|
iput(inode);
|
|
return err;
|
|
} /* ext4_group_add */
|
|
|
|
/*
|
|
* Extend the filesystem to the new number of blocks specified. This entry
|
|
* point is only used to extend the current filesystem to the end of the last
|
|
* existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
|
|
* for emergencies (because it has no dependencies on reserved blocks).
|
|
*
|
|
* If we _really_ wanted, we could use default values to call ext4_group_add()
|
|
* allow the "remount" trick to work for arbitrary resizing, assuming enough
|
|
* GDT blocks are reserved to grow to the desired size.
|
|
*/
|
|
int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
|
|
ext4_fsblk_t n_blocks_count)
|
|
{
|
|
ext4_fsblk_t o_blocks_count;
|
|
ext4_grpblk_t last;
|
|
ext4_grpblk_t add;
|
|
struct buffer_head *bh;
|
|
handle_t *handle;
|
|
int err;
|
|
ext4_group_t group;
|
|
|
|
/* We don't need to worry about locking wrt other resizers just
|
|
* yet: we're going to revalidate es->s_blocks_count after
|
|
* taking the s_resize_lock below. */
|
|
o_blocks_count = ext4_blocks_count(es);
|
|
|
|
if (test_opt(sb, DEBUG))
|
|
printk(KERN_DEBUG "EXT4-fs: extending last group from %llu uto %llu blocks\n",
|
|
o_blocks_count, n_blocks_count);
|
|
|
|
if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
|
|
return 0;
|
|
|
|
if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
|
|
printk(KERN_ERR "EXT4-fs: filesystem on %s:"
|
|
" too large to resize to %llu blocks safely\n",
|
|
sb->s_id, n_blocks_count);
|
|
if (sizeof(sector_t) < 8)
|
|
ext4_warning(sb, "CONFIG_LBDAF not enabled");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (n_blocks_count < o_blocks_count) {
|
|
ext4_warning(sb, "can't shrink FS - resize aborted");
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Handle the remaining blocks in the last group only. */
|
|
ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
|
|
|
|
if (last == 0) {
|
|
ext4_warning(sb, "need to use ext2online to resize further");
|
|
return -EPERM;
|
|
}
|
|
|
|
add = EXT4_BLOCKS_PER_GROUP(sb) - last;
|
|
|
|
if (o_blocks_count + add < o_blocks_count) {
|
|
ext4_warning(sb, "blocks_count overflow");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (o_blocks_count + add > n_blocks_count)
|
|
add = n_blocks_count - o_blocks_count;
|
|
|
|
if (o_blocks_count + add < n_blocks_count)
|
|
ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
|
|
o_blocks_count + add, add);
|
|
|
|
/* See if the device is actually as big as what was requested */
|
|
bh = sb_bread(sb, o_blocks_count + add - 1);
|
|
if (!bh) {
|
|
ext4_warning(sb, "can't read last block, resize aborted");
|
|
return -ENOSPC;
|
|
}
|
|
brelse(bh);
|
|
|
|
/* We will update the superblock, one block bitmap, and
|
|
* one group descriptor via ext4_free_blocks().
|
|
*/
|
|
handle = ext4_journal_start_sb(sb, 3);
|
|
if (IS_ERR(handle)) {
|
|
err = PTR_ERR(handle);
|
|
ext4_warning(sb, "error %d on journal start", err);
|
|
goto exit_put;
|
|
}
|
|
|
|
mutex_lock(&EXT4_SB(sb)->s_resize_lock);
|
|
if (o_blocks_count != ext4_blocks_count(es)) {
|
|
ext4_warning(sb, "multiple resizers run on filesystem!");
|
|
mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
|
|
ext4_journal_stop(handle);
|
|
err = -EBUSY;
|
|
goto exit_put;
|
|
}
|
|
|
|
if ((err = ext4_journal_get_write_access(handle,
|
|
EXT4_SB(sb)->s_sbh))) {
|
|
ext4_warning(sb, "error %d on journal write access", err);
|
|
mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
|
|
ext4_journal_stop(handle);
|
|
goto exit_put;
|
|
}
|
|
ext4_blocks_count_set(es, o_blocks_count + add);
|
|
mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
|
|
ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
|
|
o_blocks_count + add);
|
|
/* We add the blocks to the bitmap and set the group need init bit */
|
|
ext4_add_groupblocks(handle, sb, o_blocks_count, add);
|
|
ext4_handle_dirty_super(handle, sb);
|
|
ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
|
|
o_blocks_count + add);
|
|
if ((err = ext4_journal_stop(handle)))
|
|
goto exit_put;
|
|
|
|
if (test_opt(sb, DEBUG))
|
|
printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
|
|
ext4_blocks_count(es));
|
|
update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
|
|
sizeof(struct ext4_super_block));
|
|
exit_put:
|
|
return err;
|
|
} /* ext4_group_extend */
|