| /* |
| * linux/fs/ext4/resize.c |
| * |
| * Support for resizing an ext4 filesystem while it is mounted. |
| * |
| * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com> |
| * |
| * This could probably be made into a module, because it is not often in use. |
| */ |
| |
| |
| #define EXT4FS_DEBUG |
| |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| |
| #include "ext4_jbd2.h" |
| #include "group.h" |
| |
| #define outside(b, first, last) ((b) < (first) || (b) >= (last)) |
| #define inside(b, first, last) ((b) >= (first) && (b) < (last)) |
| |
| static int verify_group_input(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; |
| ext4_fsblk_t start = ext4_blocks_count(es); |
| ext4_fsblk_t end = start + input->blocks_count; |
| ext4_group_t group = input->group; |
| ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; |
| unsigned overhead = ext4_bg_has_super(sb, group) ? |
| (1 + ext4_bg_num_gdb(sb, group) + |
| le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; |
| ext4_fsblk_t metaend = start + overhead; |
| struct buffer_head *bh = NULL; |
| ext4_grpblk_t free_blocks_count, offset; |
| int err = -EINVAL; |
| |
| input->free_blocks_count = free_blocks_count = |
| input->blocks_count - 2 - overhead - sbi->s_itb_per_group; |
| |
| if (test_opt(sb, DEBUG)) |
| printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " |
| "(%d free, %u reserved)\n", |
| ext4_bg_has_super(sb, input->group) ? "normal" : |
| "no-super", input->group, input->blocks_count, |
| free_blocks_count, input->reserved_blocks); |
| |
| ext4_get_group_no_and_offset(sb, start, NULL, &offset); |
| if (group != sbi->s_groups_count) |
| ext4_warning(sb, __func__, |
| "Cannot add at group %u (only %lu groups)", |
| input->group, sbi->s_groups_count); |
| else if (offset != 0) |
| ext4_warning(sb, __func__, "Last group not full"); |
| else if (input->reserved_blocks > input->blocks_count / 5) |
| ext4_warning(sb, __func__, "Reserved blocks too high (%u)", |
| input->reserved_blocks); |
| else if (free_blocks_count < 0) |
| ext4_warning(sb, __func__, "Bad blocks count %u", |
| input->blocks_count); |
| else if (!(bh = sb_bread(sb, end - 1))) |
| ext4_warning(sb, __func__, |
| "Cannot read last block (%llu)", |
| end - 1); |
| else if (outside(input->block_bitmap, start, end)) |
| ext4_warning(sb, __func__, |
| "Block bitmap not in group (block %llu)", |
| (unsigned long long)input->block_bitmap); |
| else if (outside(input->inode_bitmap, start, end)) |
| ext4_warning(sb, __func__, |
| "Inode bitmap not in group (block %llu)", |
| (unsigned long long)input->inode_bitmap); |
| else if (outside(input->inode_table, start, end) || |
| outside(itend - 1, start, end)) |
| ext4_warning(sb, __func__, |
| "Inode table not in group (blocks %llu-%llu)", |
| (unsigned long long)input->inode_table, itend - 1); |
| else if (input->inode_bitmap == input->block_bitmap) |
| ext4_warning(sb, __func__, |
| "Block bitmap same as inode bitmap (%llu)", |
| (unsigned long long)input->block_bitmap); |
| else if (inside(input->block_bitmap, input->inode_table, itend)) |
| ext4_warning(sb, __func__, |
| "Block bitmap (%llu) in inode table (%llu-%llu)", |
| (unsigned long long)input->block_bitmap, |
| (unsigned long long)input->inode_table, itend - 1); |
| else if (inside(input->inode_bitmap, input->inode_table, itend)) |
| ext4_warning(sb, __func__, |
| "Inode bitmap (%llu) in inode table (%llu-%llu)", |
| (unsigned long long)input->inode_bitmap, |
| (unsigned long long)input->inode_table, itend - 1); |
| else if (inside(input->block_bitmap, start, metaend)) |
| ext4_warning(sb, __func__, |
| "Block bitmap (%llu) in GDT table" |
| " (%llu-%llu)", |
| (unsigned long long)input->block_bitmap, |
| start, metaend - 1); |
| else if (inside(input->inode_bitmap, start, metaend)) |
| ext4_warning(sb, __func__, |
| "Inode bitmap (%llu) in GDT table" |
| " (%llu-%llu)", |
| (unsigned long long)input->inode_bitmap, |
| start, metaend - 1); |
| else if (inside(input->inode_table, start, metaend) || |
| inside(itend - 1, start, metaend)) |
| ext4_warning(sb, __func__, |
| "Inode table (%llu-%llu) overlaps" |
| "GDT table (%llu-%llu)", |
| (unsigned long long)input->inode_table, |
| itend - 1, start, metaend - 1); |
| else |
| err = 0; |
| brelse(bh); |
| |
| return err; |
| } |
| |
| static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, |
| ext4_fsblk_t blk) |
| { |
| struct buffer_head *bh; |
| int err; |
| |
| bh = sb_getblk(sb, blk); |
| if (!bh) |
| return ERR_PTR(-EIO); |
| if ((err = ext4_journal_get_write_access(handle, bh))) { |
| brelse(bh); |
| bh = ERR_PTR(err); |
| } else { |
| lock_buffer(bh); |
| memset(bh->b_data, 0, sb->s_blocksize); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| } |
| |
| return bh; |
| } |
| |
| /* |
| * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA. |
| * If that fails, restart the transaction & regain write access for the |
| * buffer head which is used for block_bitmap modifications. |
| */ |
| static int extend_or_restart_transaction(handle_t *handle, int thresh, |
| struct buffer_head *bh) |
| { |
| int err; |
| |
| if (handle->h_buffer_credits >= thresh) |
| return 0; |
| |
| err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA); |
| if (err < 0) |
| return err; |
| if (err) { |
| if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA))) |
| return err; |
| if ((err = ext4_journal_get_write_access(handle, bh))) |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Set up the block and inode bitmaps, and the inode table for the new group. |
| * This doesn't need to be part of the main transaction, since we are only |
| * changing blocks outside the actual filesystem. We still do journaling to |
| * ensure the recovery is correct in case of a failure just after resize. |
| * If any part of this fails, we simply abort the resize. |
| */ |
| static int setup_new_group_blocks(struct super_block *sb, |
| struct ext4_new_group_data *input) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group); |
| int reserved_gdb = ext4_bg_has_super(sb, input->group) ? |
| le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0; |
| unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group); |
| struct buffer_head *bh; |
| handle_t *handle; |
| ext4_fsblk_t block; |
| ext4_grpblk_t bit; |
| int i; |
| int err = 0, err2; |
| |
| /* This transaction may be extended/restarted along the way */ |
| handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA); |
| |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| lock_super(sb); |
| if (input->group != sbi->s_groups_count) { |
| err = -EBUSY; |
| goto exit_journal; |
| } |
| |
| if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) { |
| err = PTR_ERR(bh); |
| goto exit_journal; |
| } |
| |
| if (ext4_bg_has_super(sb, input->group)) { |
| ext4_debug("mark backup superblock %#04llx (+0)\n", start); |
| ext4_set_bit(0, bh->b_data); |
| } |
| |
| /* Copy all of the GDT blocks into the backup in this group */ |
| for (i = 0, bit = 1, block = start + 1; |
| i < gdblocks; i++, block++, bit++) { |
| struct buffer_head *gdb; |
| |
| ext4_debug("update backup group %#04llx (+%d)\n", block, bit); |
| |
| if ((err = extend_or_restart_transaction(handle, 1, bh))) |
| goto exit_bh; |
| |
| gdb = sb_getblk(sb, block); |
| if (!gdb) { |
| err = -EIO; |
| goto exit_bh; |
| } |
| if ((err = ext4_journal_get_write_access(handle, gdb))) { |
| brelse(gdb); |
| goto exit_bh; |
| } |
| lock_buffer(gdb); |
| memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size); |
| set_buffer_uptodate(gdb); |
| unlock_buffer(gdb); |
| ext4_journal_dirty_metadata(handle, gdb); |
| ext4_set_bit(bit, bh->b_data); |
| brelse(gdb); |
| } |
| |
| /* Zero out all of the reserved backup group descriptor table blocks */ |
| for (i = 0, bit = gdblocks + 1, block = start + bit; |
| i < reserved_gdb; i++, block++, bit++) { |
| struct buffer_head *gdb; |
| |
| ext4_debug("clear reserved block %#04llx (+%d)\n", block, bit); |
| |
| if ((err = extend_or_restart_transaction(handle, 1, bh))) |
| goto exit_bh; |
| |
| if (IS_ERR(gdb = bclean(handle, sb, block))) { |
| err = PTR_ERR(bh); |
| goto exit_bh; |
| } |
| ext4_journal_dirty_metadata(handle, gdb); |
| ext4_set_bit(bit, bh->b_data); |
| brelse(gdb); |
| } |
| ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap, |
| input->block_bitmap - start); |
| ext4_set_bit(input->block_bitmap - start, bh->b_data); |
| ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap, |
| input->inode_bitmap - start); |
| ext4_set_bit(input->inode_bitmap - start, bh->b_data); |
| |
| /* Zero out all of the inode table blocks */ |
| for (i = 0, block = input->inode_table, bit = block - start; |
| i < sbi->s_itb_per_group; i++, bit++, block++) { |
| struct buffer_head *it; |
| |
| ext4_debug("clear inode block %#04llx (+%d)\n", block, bit); |
| |
| if ((err = extend_or_restart_transaction(handle, 1, bh))) |
| goto exit_bh; |
| |
| if (IS_ERR(it = bclean(handle, sb, block))) { |
| err = PTR_ERR(it); |
| goto exit_bh; |
| } |
| ext4_journal_dirty_metadata(handle, it); |
| brelse(it); |
| ext4_set_bit(bit, bh->b_data); |
| } |
| |
| if ((err = extend_or_restart_transaction(handle, 2, bh))) |
| goto exit_bh; |
| |
| mark_bitmap_end(input->blocks_count, EXT4_BLOCKS_PER_GROUP(sb), |
| bh->b_data); |
| ext4_journal_dirty_metadata(handle, bh); |
| brelse(bh); |
| |
| /* Mark unused entries in inode bitmap used */ |
| ext4_debug("clear inode bitmap %#04llx (+%llu)\n", |
| input->inode_bitmap, input->inode_bitmap - start); |
| if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) { |
| err = PTR_ERR(bh); |
| goto exit_journal; |
| } |
| |
| mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb), |
| bh->b_data); |
| ext4_journal_dirty_metadata(handle, bh); |
| exit_bh: |
| brelse(bh); |
| |
| exit_journal: |
| unlock_super(sb); |
| if ((err2 = ext4_journal_stop(handle)) && !err) |
| err = err2; |
| |
| return err; |
| } |
| |
| /* |
| * Iterate through the groups which hold BACKUP superblock/GDT copies in an |
| * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before |
| * calling this for the first time. In a sparse filesystem it will be the |
| * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... |
| * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... |
| */ |
| static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, |
| unsigned *five, unsigned *seven) |
| { |
| unsigned *min = three; |
| int mult = 3; |
| unsigned ret; |
| |
| if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) { |
| ret = *min; |
| *min += 1; |
| return ret; |
| } |
| |
| if (*five < *min) { |
| min = five; |
| mult = 5; |
| } |
| if (*seven < *min) { |
| min = seven; |
| mult = 7; |
| } |
| |
| ret = *min; |
| *min *= mult; |
| |
| return ret; |
| } |
| |
| /* |
| * Check that all of the backup GDT blocks are held in the primary GDT block. |
| * It is assumed that they are stored in group order. Returns the number of |
| * groups in current filesystem that have BACKUPS, or -ve error code. |
| */ |
| static int verify_reserved_gdb(struct super_block *sb, |
| struct buffer_head *primary) |
| { |
| const ext4_fsblk_t blk = primary->b_blocknr; |
| const ext4_group_t end = EXT4_SB(sb)->s_groups_count; |
| unsigned three = 1; |
| unsigned five = 5; |
| unsigned seven = 7; |
| unsigned grp; |
| __le32 *p = (__le32 *)primary->b_data; |
| int gdbackups = 0; |
| |
| while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { |
| if (le32_to_cpu(*p++) != |
| grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ |
| ext4_warning(sb, __func__, |
| "reserved GDT %llu" |
| " missing grp %d (%llu)", |
| blk, grp, |
| grp * |
| (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + |
| blk); |
| return -EINVAL; |
| } |
| if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) |
| return -EFBIG; |
| } |
| |
| return gdbackups; |
| } |
| |
| /* |
| * Called when we need to bring a reserved group descriptor table block into |
| * use from the resize inode. The primary copy of the new GDT block currently |
| * is an indirect block (under the double indirect block in the resize inode). |
| * The new backup GDT blocks will be stored as leaf blocks in this indirect |
| * block, in group order. Even though we know all the block numbers we need, |
| * we check to ensure that the resize inode has actually reserved these blocks. |
| * |
| * Don't need to update the block bitmaps because the blocks are still in use. |
| * |
| * We get all of the error cases out of the way, so that we are sure to not |
| * fail once we start modifying the data on disk, because JBD has no rollback. |
| */ |
| static int add_new_gdb(handle_t *handle, struct inode *inode, |
| struct ext4_new_group_data *input, |
| struct buffer_head **primary) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct ext4_super_block *es = EXT4_SB(sb)->s_es; |
| unsigned long gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb); |
| ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; |
| struct buffer_head **o_group_desc, **n_group_desc; |
| struct buffer_head *dind; |
| int gdbackups; |
| struct ext4_iloc iloc; |
| __le32 *data; |
| int err; |
| |
| if (test_opt(sb, DEBUG)) |
| printk(KERN_DEBUG |
| "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", |
| gdb_num); |
| |
| /* |
| * 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 |
| * bad time to do it anyways. |
| */ |
| if (EXT4_SB(sb)->s_sbh->b_blocknr != |
| le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { |
| ext4_warning(sb, __func__, |
| "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) { |
| ext4_warning(sb, __func__, |
| "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, __func__, |
| "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_journal_dirty_metadata(handle, 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_journal_dirty_metadata(handle, *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_journal_dirty_metadata(handle, 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, __func__, |
| "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_journal_dirty_metadata(handle, 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 lock_super() 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 (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_journal_dirty_metadata(handle, 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, __func__, |
| "can't update backup for group %lu (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, __func__, |
| "Can't resize non-sparse filesystem further"); |
| return -EPERM; |
| } |
| |
| if (ext4_blocks_count(es) + input->blocks_count < |
| ext4_blocks_count(es)) { |
| ext4_warning(sb, __func__, "blocks_count overflow\n"); |
| 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, __func__, "inodes_count overflow\n"); |
| return -EINVAL; |
| } |
| |
| if (reserved_gdb || gdb_off == 0) { |
| if (!EXT4_HAS_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_COMPAT_RESIZE_INODE)){ |
| ext4_warning(sb, __func__, |
| "No reserved GDT blocks, can't resize"); |
| return -EPERM; |
| } |
| inode = ext4_iget(sb, EXT4_RESIZE_INO); |
| if (IS_ERR(inode)) { |
| ext4_warning(sb, __func__, |
| "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; |
| } |
| |
| lock_super(sb); |
| if (input->group != sbi->s_groups_count) { |
| ext4_warning(sb, __func__, |
| "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. |
| * |
| * Current kernels don't lock all allocations via lock_super(), |
| * 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 *)primary->b_data + gdb_off; |
| |
| 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 */ |
| gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count); |
| gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb)); |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); |
| |
| /* |
| * 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 lock_super |
| * AND |
| * * Writers must perform a smp_wmb() after updating all dependent |
| * data and before modifying the groups count |
| * |
| * * Readers must hold lock_super() 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_journal_dirty_metadata(handle, 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)); |
| |
| ext4_journal_dirty_metadata(handle, sbi->s_sbh); |
| sb->s_dirt = 1; |
| |
| exit_journal: |
| unlock_super(sb); |
| 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_group_t o_groups_count; |
| ext4_grpblk_t last; |
| ext4_grpblk_t add; |
| struct buffer_head * bh; |
| handle_t *handle; |
| int err; |
| unsigned long freed_blocks; |
| |
| /* We don't need to worry about locking wrt other resizers just |
| * yet: we're going to revalidate es->s_blocks_count after |
| * taking lock_super() below. */ |
| o_blocks_count = ext4_blocks_count(es); |
| o_groups_count = EXT4_SB(sb)->s_groups_count; |
| |
| 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, __func__, |
| "CONFIG_LBD not enabled\n"); |
| return -EINVAL; |
| } |
| |
| if (n_blocks_count < o_blocks_count) { |
| ext4_warning(sb, __func__, |
| "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, NULL, &last); |
| |
| if (last == 0) { |
| ext4_warning(sb, __func__, |
| "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, __func__, "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, __func__, |
| "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, __func__, |
| "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, __func__, "error %d on journal start", err); |
| goto exit_put; |
| } |
| |
| lock_super(sb); |
| if (o_blocks_count != ext4_blocks_count(es)) { |
| ext4_warning(sb, __func__, |
| "multiple resizers run on filesystem!"); |
| unlock_super(sb); |
| 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, __func__, |
| "error %d on journal write access", err); |
| unlock_super(sb); |
| ext4_journal_stop(handle); |
| goto exit_put; |
| } |
| ext4_blocks_count_set(es, o_blocks_count + add); |
| ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh); |
| sb->s_dirt = 1; |
| unlock_super(sb); |
| ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, |
| o_blocks_count + add); |
| ext4_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks); |
| 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 */ |