From: Arjan van de Ven <arjanv@redhat.com> The patch below adds online resize capability to ext3 based on Andreas patch for 2.4 and fixed up by Stephen. The code ships in the FC2 kernel and while I can't say how many people are resizing there it at least doesn't break anything. Review comments: - in the ioctl: if (inode->i_sb->s_flags & MS_RDONLY) Can use IS_RDONLY. - bclean() needs to lock the buffer while clearing it and marking it uptodate. Otherwise a concurrent read of /dev/hda1 could scribble on it. - Why does setup_new_group_blocks() do lock_super()? ext3_group_add() too. And ext3_group_extend() - ext3_group_add() (and others) nest lock_super() inside transaction. Is that the right ranking? - setup_new_group_blocks() is clearing bh's by hand, and forgot to lock them. - ditto update_backups(). - ext3_journal_dirty_metadata() returns an error code, but it is often ignored. - has this been tested on big-endian machines? - ext3_group_extend() does EXT3_I(inode)->i_state = EXT3_STATE_RESIZE; which stomps on the other state bits, and nothing ever clears EXT3_STATE_RESIZE. - What's the ->i_state locking? - ext3_group_add() puts an inode on-stack. inodes are large. - How are people supposed to know how to use this? - How does it work? - Can it shrink filesytems? If so, how? - Where are the userspace tools to be obtained from? - What caveats and restrictions apply? - There are new mount options which should be documented. - Documentation/filesystems/ext3.txt should be updated - Are we sure that struct ext3_new_group_data is laid out the same way with 32- and 64-bi compilers? I spose so. Signed-off-by: Andrew Morton <akpm@osdl.org> --- 25-akpm/fs/ext3/Makefile | 2 25-akpm/fs/ext3/balloc.c | 2 25-akpm/fs/ext3/inode.c | 2 25-akpm/fs/ext3/ioctl.c | 45 + 25-akpm/fs/ext3/resize.c | 956 ++++++++++++++++++++++++++++++++++++++++ 25-akpm/fs/ext3/super.c | 26 - 25-akpm/include/linux/ext3_fs.h | 37 + 7 files changed, 1061 insertions(+), 9 deletions(-) diff -puN fs/ext3/balloc.c~ext3-online-resize-patch fs/ext3/balloc.c --- 25/fs/ext3/balloc.c~ext3-online-resize-patch 2004-06-27 17:23:59.171014456 -0700 +++ 25-akpm/fs/ext3/balloc.c 2004-06-27 17:23:59.184012480 -0700 @@ -353,7 +353,7 @@ do_more: error_return: brelse(bitmap_bh); ext3_std_error(sb, err); - if (dquot_freed_blocks) + if (dquot_freed_blocks && !(EXT3_I(inode)->i_state & EXT3_STATE_RESIZE)) DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); return; } diff -puN fs/ext3/inode.c~ext3-online-resize-patch fs/ext3/inode.c --- 25/fs/ext3/inode.c~ext3-online-resize-patch 2004-06-27 17:23:59.172014304 -0700 +++ 25-akpm/fs/ext3/inode.c 2004-06-27 17:23:59.186012176 -0700 @@ -2216,8 +2216,10 @@ static unsigned long ext3_get_inode_bloc struct buffer_head *bh; struct ext3_group_desc * gdp; + if ((ino != EXT3_ROOT_INO && ino != EXT3_JOURNAL_INO && + ino != EXT3_RESIZE_INO && ino < EXT3_FIRST_INO(sb)) || ino > le32_to_cpu( EXT3_SB(sb)->s_es->s_inodes_count)) { diff -puN fs/ext3/ioctl.c~ext3-online-resize-patch fs/ext3/ioctl.c --- 25/fs/ext3/ioctl.c~ext3-online-resize-patch 2004-06-27 17:23:59.174014000 -0700 +++ 25-akpm/fs/ext3/ioctl.c 2004-06-27 17:23:59.187012024 -0700 @@ -175,6 +175,51 @@ flags_err: rsv_window_size = EXT3_MAX_RESERVE_BLOCKS; atomic_set(&ei->i_rsv_window.rsv_goal_size, rsv_window_size); return 0; + case EXT3_IOC_GROUP_EXTEND: { + unsigned long n_blocks_count; + struct super_block *sb = inode->i_sb; + int err; + + if (!capable(CAP_SYS_RESOURCE)) + return -EACCES; + + if (sb->s_flags & MS_RDONLY) + return -EROFS; + + if (get_user(n_blocks_count, (__u32 *)arg)) + return -EFAULT; + + err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count); + journal_lock_updates(EXT3_SB(sb)->s_journal); + journal_flush(EXT3_SB(sb)->s_journal); + journal_unlock_updates(EXT3_SB(sb)->s_journal); + + return err; + } + case EXT3_IOC_GROUP_ADD: { + struct ext3_new_group_data input; + struct super_block *sb = inode->i_sb; + int err; + + if (!capable(CAP_SYS_RESOURCE)) + return -EACCES; + + if (inode->i_sb->s_flags & MS_RDONLY) + return -EROFS; + + if (copy_from_user(&input, (struct ext3_new_group_input *)arg, + sizeof(input))) + return -EFAULT; + + err = ext3_group_add(sb, &input); + journal_lock_updates(EXT3_SB(sb)->s_journal); + journal_flush(EXT3_SB(sb)->s_journal); + journal_unlock_updates(EXT3_SB(sb)->s_journal); + + return err; + } + + default: return -ENOTTY; } diff -puN fs/ext3/Makefile~ext3-online-resize-patch fs/ext3/Makefile --- 25/fs/ext3/Makefile~ext3-online-resize-patch 2004-06-27 17:23:59.175013848 -0700 +++ 25-akpm/fs/ext3/Makefile 2004-06-27 17:23:59.187012024 -0700 @@ -5,7 +5,7 @@ obj-$(CONFIG_EXT3_FS) += ext3.o ext3-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ - ioctl.o namei.o super.o symlink.o hash.o + ioctl.o namei.o super.o symlink.o hash.o resize.o ext3-$(CONFIG_EXT3_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o ext3-$(CONFIG_EXT3_FS_POSIX_ACL) += acl.o diff -puN /dev/null fs/ext3/resize.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ 25-akpm/fs/ext3/resize.c 2004-06-27 17:23:59.192011264 -0700 @@ -0,0 +1,956 @@ +/* + * linux/fs/ext3/resize.c + * + * Support for resizing an ext3 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. + */ + +#include <linux/config.h> + +#define EXT3FS_DEBUG + +#include <linux/sched.h> +#include <linux/smp_lock.h> +#include <linux/ext3_jbd.h> + +#include <linux/errno.h> +#include <linux/slab.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 ext3_new_group_data *input) +{ + struct ext3_sb_info *sbi = EXT3_SB(sb); + struct ext3_super_block *es = sbi->s_es; + unsigned start = le32_to_cpu(es->s_blocks_count); + unsigned end = start + input->blocks_count; + unsigned group = input->group; + unsigned itend = input->inode_table + EXT3_SB(sb)->s_itb_per_group; + unsigned overhead = ext3_bg_has_super(sb, group) ? + (1 + ext3_bg_num_gdb(sb, group) + + le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; + unsigned metaend = start + overhead; + struct buffer_head *bh; + int free_blocks_count; + 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("EXT3-fs: adding %s group %u: %u blocks " + "(%d free, %u reserved)\n", + ext3_bg_has_super(sb, input->group) ? "normal" : + "no-super", input->group, input->blocks_count, + free_blocks_count, input->reserved_blocks); + + if (group != sbi->s_groups_count) + ext3_warning(sb, __FUNCTION__, + "Cannot add at group %u (only %lu groups)", + input->group, sbi->s_groups_count); + else if ((start - le32_to_cpu(es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb)) + ext3_warning(sb, __FUNCTION__, "Last group not full"); + else if (input->reserved_blocks > input->blocks_count / 5) + ext3_warning(sb, __FUNCTION__, "Reserved blocks too high (%u)", + input->reserved_blocks); + else if (free_blocks_count < 0) + ext3_warning(sb, __FUNCTION__, "Bad blocks count %u", + input->blocks_count); + else if (!(bh = sb_bread(sb, end - 1))) + ext3_warning(sb, __FUNCTION__, "Cannot read last block (%u)", + end - 1); + else if (outside(input->block_bitmap, start, end)) + ext3_warning(sb, __FUNCTION__, + "Block bitmap not in group (block %u)", + input->block_bitmap); + else if (outside(input->inode_bitmap, start, end)) + ext3_warning(sb, __FUNCTION__, + "Inode bitmap not in group (block %u)", + input->inode_bitmap); + else if (outside(input->inode_table, start, end) || + outside(itend - 1, start, end)) + ext3_warning(sb, __FUNCTION__, + "Inode table not in group (blocks %u-%u)", + input->inode_table, itend - 1); + else if (input->inode_bitmap == input->block_bitmap) + ext3_warning(sb, __FUNCTION__, + "Block bitmap same as inode bitmap (%u)", + input->block_bitmap); + else if (inside(input->block_bitmap, input->inode_table, itend)) + ext3_warning(sb, __FUNCTION__, + "Block bitmap (%u) in inode table (%u-%u)", + input->block_bitmap, input->inode_table, itend-1); + else if (inside(input->inode_bitmap, input->inode_table, itend)) + ext3_warning(sb, __FUNCTION__, + "Inode bitmap (%u) in inode table (%u-%u)", + input->inode_bitmap, input->inode_table, itend-1); + else if (inside(input->block_bitmap, start, metaend)) + ext3_warning(sb, __FUNCTION__, + "Block bitmap (%u) in GDT table (%u-%u)", + input->block_bitmap, start, metaend - 1); + else if (inside(input->inode_bitmap, start, metaend)) + ext3_warning(sb, __FUNCTION__, + "Inode bitmap (%u) in GDT table (%u-%u)", + input->inode_bitmap, start, metaend - 1); + else if (inside(input->inode_table, start, metaend) || + inside(itend - 1, start, metaend)) + ext3_warning(sb, __FUNCTION__, + "Inode table (%u-%u) overlaps GDT table (%u-%u)", + input->inode_table, itend - 1, start, metaend - 1); + else { + brelse(bh); + err = 0; + } + + return err; +} + +static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, + unsigned long blk) +{ + struct buffer_head *bh; + int err; + + bh = sb_getblk(sb, blk); + set_buffer_uptodate(bh); + if ((err = ext3_journal_get_write_access(handle, bh))) { + brelse(bh); + bh = ERR_PTR(err); + } else + memset(bh->b_data, 0, sb->s_blocksize); + + return bh; +} + +/* + * To avoid calling the atomic setbit hundreds or thousands of times, we only + * need to use it within a single byte (to ensure we get endianness right). + * We can use memset for the rest of the bitmap as there are no other users. + */ +static void mark_bitmap_end(int start_bit, int end_bit, char *bitmap) +{ + int i; + + if (start_bit >= end_bit) + return; + + ext3_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); + for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) + ext3_set_bit(i, bitmap); + if (i < end_bit) + memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); +} + +/* + * 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. + * + * We only pass inode because of the ext3 journal wrappers. + */ +static int setup_new_group_blocks(struct super_block *sb, struct inode *inode, + struct ext3_new_group_data *input) +{ + struct ext3_sb_info *sbi = EXT3_SB(sb); + unsigned long start = input->group * sbi->s_blocks_per_group + + le32_to_cpu(sbi->s_es->s_first_data_block); + int reserved_gdb = ext3_bg_has_super(sb, input->group) ? + le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0; + unsigned long gdblocks = ext3_bg_num_gdb(sb, input->group); + struct buffer_head *bh; + handle_t *handle; + unsigned long block; + int bit; + int i; + int err = 0, err2; + + handle = ext3_journal_start(inode, reserved_gdb + gdblocks + + 2 + sbi->s_itb_per_group); + 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 (ext3_bg_has_super(sb, input->group)) { + ext3_debug("mark backup superblock %#04lx (+0)\n", start); + ext3_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; + + ext3_debug("update backup group %#04lx (+%d)\n", block, bit); + + gdb = sb_getblk(sb, block); + set_buffer_uptodate(gdb); + if ((err = ext3_journal_get_write_access(handle, gdb))) { + brelse(gdb); + goto exit_bh; + } + memcpy(gdb->b_data, sbi->s_group_desc[i], bh->b_size); + ext3_journal_dirty_metadata(handle, gdb); + ext3_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; + + ext3_debug("clear reserved block %#04lx (+%d)\n", block, bit); + + if (IS_ERR(gdb = bclean(handle, sb, block))) { + err = PTR_ERR(bh); + goto exit_bh; + } + ext3_journal_dirty_metadata(handle, gdb); + ext3_set_bit(bit, bh->b_data); + brelse(gdb); + } + ext3_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap, + input->block_bitmap - start); + ext3_set_bit(input->block_bitmap - start, bh->b_data); + ext3_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap, + input->inode_bitmap - start); + ext3_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; + + ext3_debug("clear inode block %#04x (+%ld)\n", block, bit); + if (IS_ERR(it = bclean(handle, sb, block))) { + err = PTR_ERR(it); + goto exit_bh; + } + ext3_journal_dirty_metadata(handle, it); + brelse(it); + ext3_set_bit(bit, bh->b_data); + } + mark_bitmap_end(input->blocks_count, EXT3_BLOCKS_PER_GROUP(sb), + bh->b_data); + ext3_journal_dirty_metadata(handle, bh); + brelse(bh); + + /* Mark unused entries in inode bitmap used */ + ext3_debug("clear inode bitmap %#04x (+%ld)\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(EXT3_INODES_PER_GROUP(sb), EXT3_BLOCKS_PER_GROUP(sb), + bh->b_data); + ext3_journal_dirty_metadata(handle, bh); +exit_bh: + brelse(bh); + +exit_journal: + unlock_super(sb); + if ((err2 = ext3_journal_stop(handle)) && !err) + err = err2; + + return err; +} + +/* + * Iterate through the groups which hold BACKUP superblock/GDT copies in an + * ext3 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, ... + */ +unsigned ext3_list_backups(struct super_block *sb, unsigned *three, + unsigned *five, unsigned *seven) +{ + unsigned *min = three; + int mult = 3; + unsigned ret; + + if (!EXT3_HAS_RO_COMPAT_FEATURE(sb, + EXT3_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 unsigned long blk = primary->b_blocknr; + const unsigned long end = EXT3_SB(sb)->s_groups_count; + unsigned three = 1; + unsigned five = 5; + unsigned seven = 7; + unsigned grp; + __u32 *p = (__u32 *)primary->b_data; + int gdbackups = 0; + + while ((grp = ext3_list_backups(sb, &three, &five, &seven)) < end) { + if (le32_to_cpu(*p++) != grp * EXT3_BLOCKS_PER_GROUP(sb) + blk){ + ext3_warning(sb, __FUNCTION__, + "reserved GDT %ld missing grp %d (%ld)\n", + blk, grp, + grp * EXT3_BLOCKS_PER_GROUP(sb) + blk); + return -EINVAL; + } + if (++gdbackups > EXT3_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 ext3_new_group_data *input, + struct buffer_head **primary) +{ + struct super_block *sb = inode->i_sb; + struct ext3_super_block *es = EXT3_SB(sb)->s_es; + unsigned long gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb); + unsigned long gdb_off = input->group % EXT3_DESC_PER_BLOCK(sb); + unsigned long gdblock = EXT3_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 ext3_iloc iloc; + __u32 *data; + int err; + + if (test_opt(sb, DEBUG)) + printk("EXT3-fs: ext3_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 (EXT3_SB(sb)->s_sbh->b_blocknr != + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) { + ext3_warning(sb, __FUNCTION__, + "won't resize using backup superblock at %lu\n", + EXT3_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 = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK; + dind = sb_bread(sb, le32_to_cpu(*data)); + if (!dind) { + err = -EIO; + goto exit_bh; + } + + data = (__u32 *)dind->b_data; + if (le32_to_cpu(data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)]) != gdblock) { + ext3_warning(sb, __FUNCTION__, + "new group %u GDT block %lu not reserved\n", + input->group, gdblock); + err = -EINVAL; + goto exit_dind; + } + + if ((err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh))) + goto exit_dind; + + if ((err = ext3_journal_get_write_access(handle, *primary))) + goto exit_sbh; + + if ((err = ext3_journal_get_write_access(handle, dind))) + goto exit_primary; + + /* ext3_reserve_inode_write() gets a reference on the iloc */ + if ((err = ext3_reserve_inode_write(handle, inode, &iloc))) + goto exit_dindj; + + n_group_desc = (struct buffer_head **)kmalloc((gdb_num + 1) * + sizeof(struct buffer_head *), GFP_KERNEL); + if (!n_group_desc) { + err = -ENOMEM; + ext3_warning (sb, __FUNCTION__, + "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). + */ + /* + printk("removing block %d = %ld from dindir %ld[%ld]\n", + ((__u32 *)(dind->b_data))[gdb_off], gdblock, dind->b_blocknr, + gdb_num); */ + data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)] = 0; + ext3_journal_dirty_metadata(handle, dind); + brelse(dind); + inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9; + ext3_mark_iloc_dirty(handle, inode, &iloc); + memset((*primary)->b_data, 0, sb->s_blocksize); + ext3_journal_dirty_metadata(handle, *primary); + + o_group_desc = EXT3_SB(sb)->s_group_desc; + memcpy(n_group_desc, o_group_desc, + EXT3_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); + n_group_desc[gdb_num] = *primary; + EXT3_SB(sb)->s_group_desc = n_group_desc; + EXT3_SB(sb)->s_gdb_count++; + kfree(o_group_desc); + + es->s_reserved_gdt_blocks = + cpu_to_le16(le16_to_cpu(es->s_reserved_gdt_blocks) - 1); + ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); + + return 0; + +exit_inode: + //ext3_journal_release_buffer(handle, iloc.bh); + brelse(iloc.bh); +exit_dindj: + //ext3_journal_release_buffer(handle, dind); +exit_primary: + //ext3_journal_release_buffer(handle, *primary); +exit_sbh: + //ext3_journal_release_buffer(handle, *primary); +exit_dind: + brelse(dind); +exit_bh: + brelse(*primary); + + ext3_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 ext3_new_group_data *input) +{ + struct super_block *sb = inode->i_sb; + int reserved_gdb =le16_to_cpu(EXT3_SB(sb)->s_es->s_reserved_gdt_blocks); + struct buffer_head **primary; + struct buffer_head *dind; + struct ext3_iloc iloc; + unsigned long blk; + __u32 *data, *end; + int gdbackups = 0; + int res, i; + int err; + + primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_KERNEL); + if (!primary) + return -ENOMEM; + + data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK; + dind = sb_bread(sb, le32_to_cpu(*data)); + if (!dind) { + err = -EIO; + goto exit_free; + } + + blk = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + EXT3_SB(sb)->s_gdb_count; + data = (__u32 *)dind->b_data + EXT3_SB(sb)->s_gdb_count; + end = (__u32 *)dind->b_data + EXT3_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) { + ext3_warning(sb, __FUNCTION__, + "reserved block %lu not at offset %ld\n", + blk, (long)(data - (__u32 *)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 = (__u32 *)dind->b_data; + } + + for (i = 0; i < reserved_gdb; i++) { + if ((err = ext3_journal_get_write_access(handle, primary[i]))) { + /* + int j; + for (j = 0; j < i; j++) + ext3_journal_release_buffer(handle, primary[j]); + */ + goto exit_bh; + } + } + + if ((err = ext3_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 * EXT3_BLOCKS_PER_GROUP(sb); + for (i = 0; i < reserved_gdb; i++) { + int err2; + data = (__u32 *)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 = ext3_journal_dirty_metadata(handle, primary[i]); + if (!err) + err = err2; + } + inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9; + ext3_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 ext3 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. + * + * We only pass inode because of the ext3 journal wrappers. + */ +static void update_backups(struct super_block *sb, struct inode *inode, + int blk_off, char *data, int size) +{ + struct ext3_sb_info *sbi = EXT3_SB(sb); + const unsigned long last = sbi->s_groups_count; + const int bpg = EXT3_BLOCKS_PER_GROUP(sb); + unsigned three = 1; + unsigned five = 5; + unsigned seven = 7; + unsigned group; + int rest = sb->s_blocksize - size; + handle_t *handle; + int err = 0, err2; + + handle = ext3_journal_start(inode, EXT3_MAX_TRANS_DATA); + if (IS_ERR(handle)) { + group = 1; + err = PTR_ERR(handle); + goto exit_err; + } + + while ((group = ext3_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 && + ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA) && + (err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA))) + break; + + bh = sb_getblk(sb, group * bpg + blk_off); + set_buffer_uptodate(bh); + ext3_debug(sb, __FUNCTION__, "update metadata backup %#04lx\n", + bh->b_blocknr); + if ((err = ext3_journal_get_write_access(handle, bh))) + break; + memcpy(bh->b_data, data, size); + if (rest) + memset(bh->b_data + size, 0, rest); + ext3_journal_dirty_metadata(handle, bh); + brelse(bh); + } + if ((err2 = ext3_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) { + ext3_warning(sb, __FUNCTION__, + "can't update backup for group %d (err %d), " + "forcing fsck on next reboot\n", group, err); + sbi->s_mount_state &= ~EXT3_VALID_FS; + sbi->s_es->s_state &= ~cpu_to_le16(EXT3_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 ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input) +{ + struct ext3_sb_info *sbi = EXT3_SB(sb); + struct ext3_super_block *es = sbi->s_es; + int reserved_gdb = ext3_bg_has_super(sb, input->group) ? + le16_to_cpu(es->s_reserved_gdt_blocks) : 0; + struct buffer_head *primary = NULL; + struct ext3_group_desc *gdp; + struct inode *inode = NULL; + struct inode bogus; + handle_t *handle; + int gdb_off, gdb_num; + int err, err2; + + gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb); + gdb_off = input->group % EXT3_DESC_PER_BLOCK(sb); + + if (gdb_off == 0 && !EXT3_HAS_RO_COMPAT_FEATURE(sb, + EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) { + ext3_warning(sb, __FUNCTION__, + "Can't resize non-sparse filesystem further\n"); + return -EPERM; + } + + if (reserved_gdb || gdb_off == 0) { + if (!EXT3_HAS_COMPAT_FEATURE(sb, + EXT3_FEATURE_COMPAT_RESIZE_INODE)){ + ext3_warning(sb, __FUNCTION__, + "No reserved GDT blocks, can't resize\n"); + return -EPERM; + } + inode = iget(sb, EXT3_RESIZE_INO); + if (!inode || is_bad_inode(inode)) { + ext3_warning(sb, __FUNCTION__, + "Error opening resize inode\n"); + iput(inode); + return -ENOENT; + } + } else { + /* Used only for ext3 journal wrapper functions to get sb */ + inode = &bogus; + bogus.i_sb = sb; + } + + if ((err = verify_group_input(sb, input))) + goto exit_put; + + if ((err = setup_new_group_blocks(sb, inode, 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 = ext3_journal_start(inode, ext3_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 != EXT3_SB(sb)->s_groups_count) { + ext3_warning(sb, __FUNCTION__, + "multiple resizers run on filesystem!\n"); + goto exit_journal; + } + + if ((err = ext3_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 = ext3_journal_get_write_access(handle, primary))) + goto exit_journal; + + if (reserved_gdb && ext3_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; + + /* Finally update group descriptor block for new group */ + gdp = (struct ext3_group_desc *)primary->b_data + gdb_off; + + gdp->bg_block_bitmap = cpu_to_le32(input->block_bitmap); + gdp->bg_inode_bitmap = cpu_to_le32(input->inode_bitmap); + gdp->bg_inode_table = cpu_to_le32(input->inode_table); + gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count); + gdp->bg_free_inodes_count = cpu_to_le16(EXT3_INODES_PER_GROUP(sb)); + + EXT3_SB(sb)->s_groups_count++; + ext3_journal_dirty_metadata(handle, primary); + + /* Update superblock with new block counts */ + es->s_blocks_count = cpu_to_le32(le32_to_cpu(es->s_blocks_count) + + input->blocks_count); + es->s_free_blocks_count = + cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) + + input->free_blocks_count); + es->s_r_blocks_count = cpu_to_le32(le32_to_cpu(es->s_r_blocks_count) + + input->reserved_blocks); + es->s_inodes_count = cpu_to_le32(le32_to_cpu(es->s_inodes_count) + + EXT3_INODES_PER_GROUP(sb)); + es->s_free_inodes_count = + cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + + EXT3_INODES_PER_GROUP(sb)); + ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); + sb->s_dirt = 1; + +exit_journal: + unlock_super(sb); + handle->h_sync = 1; + if ((err2 = ext3_journal_stop(handle)) && !err) + err = err2; + if (!err) { + update_backups(sb, inode, sbi->s_sbh->b_blocknr, (char *)es, + sizeof(struct ext3_super_block)); + update_backups(sb, inode, primary->b_blocknr, primary->b_data, + primary->b_size); + } +exit_put: + if (inode != &bogus) + iput(inode); + return err; +} /* ext3_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 ext3_group_add() + * allow the "remount" trick to work for arbitrary resizing, assuming enough + * GDT blocks are reserved to grow to the desired size. + */ +int ext3_group_extend(struct super_block *sb, struct ext3_super_block *es, + unsigned long n_blocks_count) +{ + unsigned long o_blocks_count; + unsigned long o_groups_count; + unsigned long last; + int add; + struct inode *inode; + struct buffer_head * bh; + handle_t *handle; + int err; + + o_blocks_count = le32_to_cpu(es->s_blocks_count); + o_groups_count = EXT3_SB(sb)->s_groups_count; + + if (test_opt(sb, DEBUG)) + printk("EXT3-fs: extending last group from %lu to %lu 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 < o_blocks_count) { + ext3_warning(sb, __FUNCTION__, + "can't shrink FS - resize aborted"); + return -EBUSY; + } + + /* Handle the remaining blocks in the last group only. */ + last = (o_blocks_count - le32_to_cpu(es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb); + + if (last == 0) { + ext3_warning(sb, __FUNCTION__, + "need to use ext2online to resize further\n"); + return -EPERM; + } + + add = EXT3_BLOCKS_PER_GROUP(sb) - last; + + if (o_blocks_count + add > n_blocks_count) + add = n_blocks_count - o_blocks_count; + + if (o_blocks_count + add < n_blocks_count) + ext3_warning(sb, __FUNCTION__, + "will only finish group (%lu 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) { + ext3_warning(sb, __FUNCTION__, + "can't read last block, resize aborted"); + return -ENOSPC; + } + brelse(bh); + + /* Get a bogus inode to "free" the new blocks in this group. */ + if (!(inode = new_inode(sb))) { + ext3_warning(sb, __FUNCTION__, + "error getting dummy resize inode"); + return -ENOMEM; + } + inode->i_ino = 0; + + EXT3_I(inode)->i_state = EXT3_STATE_RESIZE; + + /* We will update the superblock, one block bitmap, and + * one group descriptor via ext3_free_blocks(). + */ + handle = ext3_journal_start(inode, 3); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + ext3_warning(sb, __FUNCTION__, "error %d on journal start",err); + goto exit_put; + } + + lock_super(sb); + if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) { + ext3_warning(sb, __FUNCTION__, + "multiple resizers run on filesystem!\n"); + err = -EBUSY; + goto exit_put; + } + + if ((err = ext3_journal_get_write_access(handle, + EXT3_SB(sb)->s_sbh))) { + ext3_warning(sb, __FUNCTION__, + "error %d on journal write access", err); + unlock_super(sb); + ext3_journal_stop(handle); + goto exit_put; + } + es->s_blocks_count = cpu_to_le32(o_blocks_count + add); + ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); + sb->s_dirt = 1; + unlock_super(sb); + ext3_debug("freeing blocks %ld through %ld\n", o_blocks_count, + o_blocks_count + add); + ext3_free_blocks(handle, inode, o_blocks_count, add); + ext3_debug("freed blocks %ld through %ld\n", o_blocks_count, + o_blocks_count + add); + if ((err = ext3_journal_stop(handle))) + goto exit_put; + if (test_opt(sb, DEBUG)) + printk("EXT3-fs: extended group to %u blocks\n", + le32_to_cpu(es->s_blocks_count)); + update_backups(sb, inode, EXT3_SB(sb)->s_sbh->b_blocknr, (char *)es, + sizeof(struct ext3_super_block)); +exit_put: + iput(inode); + + return err; +} /* ext3_group_extend */ diff -puN fs/ext3/super.c~ext3-online-resize-patch fs/ext3/super.c --- 25/fs/ext3/super.c~ext3-online-resize-patch 2004-06-27 17:23:59.177013544 -0700 +++ 25-akpm/fs/ext3/super.c 2004-06-27 17:23:59.195010808 -0700 @@ -585,7 +585,7 @@ enum { Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback, Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota, Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, - Opt_ignore, Opt_barrier, Opt_err, + Opt_ignore, Opt_barrier, Opt_err, Opt_resize, }; static match_table_t tokens = { @@ -633,7 +633,8 @@ static match_table_t tokens = { {Opt_ignore, "quota"}, {Opt_ignore, "usrquota"}, {Opt_barrier, "barrier=%u"}, - {Opt_err, NULL} + {Opt_err, NULL}, + {Opt_resize, "resize"}, }; static unsigned long get_sb_block(void **data) @@ -657,7 +658,7 @@ static unsigned long get_sb_block(void * } static int parse_options (char * options, struct super_block *sb, - unsigned long * inum, int is_remount) + unsigned long * inum, unsigned long *n_blocks_count, int is_remount) { struct ext3_sb_info *sbi = EXT3_SB(sb); char * p; @@ -914,6 +915,15 @@ clear_qf_name: break; case Opt_ignore: break; + case Opt_resize: + if (!n_blocks_count) { + printk("EXT3-fs: resize option only available " + "for remount\n"); + return 0; + } + match_int(&args[0], &option); + *n_blocks_count = option; + break; default: printk (KERN_ERR "EXT3-fs: Unrecognized mount option \"%s\" " @@ -1305,7 +1315,7 @@ static int ext3_fill_super (struct super set_opt(sbi->s_mount_opt, RESERVATION); - if (!parse_options ((char *) data, sb, &journal_inum, 0)) + if (!parse_options ((char *) data, sb, &journal_inum, NULL, 0)) goto failed_mount; sb->s_flags |= MS_ONE_SECOND; @@ -2045,11 +2055,12 @@ int ext3_remount (struct super_block * s struct ext3_super_block * es; struct ext3_sb_info *sbi = EXT3_SB(sb); unsigned long tmp; + unsigned long n_blocks_count = 0; /* * Allow the "check" option to be passed as a remount option. */ - if (!parse_options(data, sb, &tmp, 1)) + if (!parse_options(data, sb, &tmp, &n_blocks_count, 1)) return -EINVAL; if (sbi->s_mount_opt & EXT3_MOUNT_ABORT) @@ -2062,7 +2073,8 @@ int ext3_remount (struct super_block * s ext3_init_journal_params(sb, sbi->s_journal); - if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) { + if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) || + n_blocks_count > le32_to_cpu(es->s_blocks_count)) { if (sbi->s_mount_opt & EXT3_MOUNT_ABORT) return -EROFS; @@ -2101,6 +2113,8 @@ int ext3_remount (struct super_block * s */ ext3_clear_journal_err(sb, es); sbi->s_mount_state = le16_to_cpu(es->s_state); + if ((ret = ext3_group_extend(sb, es, n_blocks_count))) + return ret; if (!ext3_setup_super (sb, es, 0)) sb->s_flags &= ~MS_RDONLY; } diff -puN include/linux/ext3_fs.h~ext3-online-resize-patch include/linux/ext3_fs.h --- 25/include/linux/ext3_fs.h~ext3-online-resize-patch 2004-06-27 17:23:59.179013240 -0700 +++ 25-akpm/include/linux/ext3_fs.h 2004-06-27 17:23:59.196010656 -0700 @@ -194,6 +194,32 @@ struct ext3_group_desc */ #define EXT3_STATE_JDATA 0x00000001 /* journaled data exists */ #define EXT3_STATE_NEW 0x00000002 /* inode is newly created */ +#define EXT3_STATE_RESIZE 0x00000004 /* fake inode for resizing */ + + +/* Used to pass group descriptor data when online resize is done */ +struct ext3_new_group_input { + __u32 group; /* Group number for this data */ + __u32 block_bitmap; /* Absolute block number of block bitmap */ + __u32 inode_bitmap; /* Absolute block number of inode bitmap */ + __u32 inode_table; /* Absolute block number of inode table start */ + __u32 blocks_count; /* Total number of blocks in this group */ + __u16 reserved_blocks; /* Number of reserved blocks in this group */ + __u16 unused; +}; + +/* The struct ext3_new_group_input in kernel space, with free_blocks_count */ +struct ext3_new_group_data { + __u32 group; + __u32 block_bitmap; + __u32 inode_bitmap; + __u32 inode_table; + __u32 blocks_count; + __u16 reserved_blocks; + __u16 unused; + __u32 free_blocks_count; +}; + /* * ioctl commands @@ -202,6 +228,8 @@ struct ext3_group_desc #define EXT3_IOC_SETFLAGS _IOW('f', 2, long) #define EXT3_IOC_GETVERSION _IOR('f', 3, long) #define EXT3_IOC_SETVERSION _IOW('f', 4, long) +#define EXT3_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long) +#define EXT3_IOC_GROUP_ADD _IOW('f', 8,struct ext3_new_group_input) #define EXT3_IOC_GETVERSION_OLD _IOR('v', 1, long) #define EXT3_IOC_SETVERSION_OLD _IOW('v', 2, long) #ifdef CONFIG_JBD_DEBUG @@ -420,7 +448,7 @@ struct ext3_super_block { */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ - __u16 s_padding1; + __u16 s_reserved_gdt_blocks; /* Per group desc for online growth */ /* * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. */ @@ -748,6 +776,13 @@ extern int ext3_orphan_del(handle_t *, s extern int ext3_htree_fill_tree(struct file *dir_file, __u32 start_hash, __u32 start_minor_hash, __u32 *next_hash); +/* resize.c */ +extern int ext3_group_add(struct super_block *sb, + struct ext3_new_group_data *input); +extern int ext3_group_extend(struct super_block *sb, + struct ext3_super_block *es, + unsigned long n_blocks_count); + /* super.c */ extern void ext3_error (struct super_block *, const char *, const char *, ...) __attribute__ ((format (printf, 3, 4))); _