diff options
Diffstat (limited to 'kernel/fs/ext3/resize.c')
| -rw-r--r-- | kernel/fs/ext3/resize.c | 1117 |
1 files changed, 0 insertions, 1117 deletions
diff --git a/kernel/fs/ext3/resize.c b/kernel/fs/ext3/resize.c deleted file mode 100644 index 271056555..000000000 --- a/kernel/fs/ext3/resize.c +++ /dev/null @@ -1,1117 +0,0 @@ -/* - * 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. - */ - - -#define EXT3FS_DEBUG - -#include "ext3.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; - ext3_fsblk_t start = le32_to_cpu(es->s_blocks_count); - ext3_fsblk_t end = start + input->blocks_count; - unsigned group = input->group; - ext3_fsblk_t itend = input->inode_table + sbi->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; - ext3_fsblk_t metaend = start + overhead; - struct buffer_head *bh = NULL; - ext3_grpblk_t 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(KERN_DEBUG "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, __func__, - "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, __func__, "Last group not full"); - else if (input->reserved_blocks > input->blocks_count / 5) - ext3_warning(sb, __func__, "Reserved blocks too high (%u)", - input->reserved_blocks); - else if (free_blocks_count < 0) - ext3_warning(sb, __func__, "Bad blocks count %u", - input->blocks_count); - else if (!(bh = sb_bread(sb, end - 1))) - ext3_warning(sb, __func__, - "Cannot read last block ("E3FSBLK")", - end - 1); - else if (outside(input->block_bitmap, start, end)) - ext3_warning(sb, __func__, - "Block bitmap not in group (block %u)", - input->block_bitmap); - else if (outside(input->inode_bitmap, start, end)) - ext3_warning(sb, __func__, - "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, __func__, - "Inode table not in group (blocks %u-"E3FSBLK")", - input->inode_table, itend - 1); - else if (input->inode_bitmap == input->block_bitmap) - ext3_warning(sb, __func__, - "Block bitmap same as inode bitmap (%u)", - input->block_bitmap); - else if (inside(input->block_bitmap, input->inode_table, itend)) - ext3_warning(sb, __func__, - "Block bitmap (%u) in inode table (%u-"E3FSBLK")", - input->block_bitmap, input->inode_table, itend-1); - else if (inside(input->inode_bitmap, input->inode_table, itend)) - ext3_warning(sb, __func__, - "Inode bitmap (%u) in inode table (%u-"E3FSBLK")", - input->inode_bitmap, input->inode_table, itend-1); - else if (inside(input->block_bitmap, start, metaend)) - ext3_warning(sb, __func__, - "Block bitmap (%u) in GDT table" - " ("E3FSBLK"-"E3FSBLK")", - input->block_bitmap, start, metaend - 1); - else if (inside(input->inode_bitmap, start, metaend)) - ext3_warning(sb, __func__, - "Inode bitmap (%u) in GDT table" - " ("E3FSBLK"-"E3FSBLK")", - input->inode_bitmap, start, metaend - 1); - else if (inside(input->inode_table, start, metaend) || - inside(itend - 1, start, metaend)) - ext3_warning(sb, __func__, - "Inode table (%u-"E3FSBLK") overlaps" - "GDT table ("E3FSBLK"-"E3FSBLK")", - 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, - ext3_fsblk_t blk) -{ - struct buffer_head *bh; - int err; - - bh = sb_getblk(sb, blk); - if (unlikely(!bh)) - return ERR_PTR(-ENOMEM); - if ((err = ext3_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; -} - -/* - * 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); -} - -/* - * If we have fewer than thresh credits, extend by EXT3_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 = ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA); - if (err < 0) - return err; - if (err) { - err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA); - if (err) - return err; - err = ext3_journal_get_write_access(handle, bh); - if (err) - 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 ext3_new_group_data *input) -{ - struct ext3_sb_info *sbi = EXT3_SB(sb); - ext3_fsblk_t start = ext3_group_first_block_no(sb, input->group); - 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; - ext3_fsblk_t block; - ext3_grpblk_t bit; - int i; - int err = 0, err2; - - /* This transaction may be extended/restarted along the way */ - handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA); - - if (IS_ERR(handle)) - return PTR_ERR(handle); - - mutex_lock(&sbi->s_resize_lock); - 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); - - err = extend_or_restart_transaction(handle, 1, bh); - if (err) - goto exit_bh; - - gdb = sb_getblk(sb, block); - if (unlikely(!gdb)) { - err = -ENOMEM; - goto exit_bh; - } - if ((err = ext3_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); - err = ext3_journal_dirty_metadata(handle, gdb); - if (err) { - brelse(gdb); - goto exit_bh; - } - 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); - - err = extend_or_restart_transaction(handle, 1, bh); - if (err) - goto exit_bh; - - if (IS_ERR(gdb = bclean(handle, sb, block))) { - err = PTR_ERR(gdb); - goto exit_bh; - } - err = ext3_journal_dirty_metadata(handle, gdb); - if (err) { - brelse(gdb); - goto exit_bh; - } - 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 %#04lx (+%d)\n", block, bit); - - err = extend_or_restart_transaction(handle, 1, bh); - if (err) - goto exit_bh; - - if (IS_ERR(it = bclean(handle, sb, block))) { - err = PTR_ERR(it); - goto exit_bh; - } - err = ext3_journal_dirty_metadata(handle, it); - if (err) { - brelse(it); - goto exit_bh; - } - brelse(it); - ext3_set_bit(bit, bh->b_data); - } - - err = extend_or_restart_transaction(handle, 2, bh); - if (err) - goto exit_bh; - - mark_bitmap_end(input->blocks_count, EXT3_BLOCKS_PER_GROUP(sb), - bh->b_data); - err = ext3_journal_dirty_metadata(handle, bh); - if (err) - goto exit_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); - err = ext3_journal_dirty_metadata(handle, bh); -exit_bh: - brelse(bh); - -exit_journal: - mutex_unlock(&sbi->s_resize_lock); - 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, ... - */ -static 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 ext3_fsblk_t 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; - __le32 *p = (__le32 *)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, __func__, - "reserved GDT "E3FSBLK - " missing grp %d ("E3FSBLK")", - 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); - ext3_fsblk_t 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; - __le32 *data; - int err; - - if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG - "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, __func__, - "won't resize using backup superblock at %llu", - (unsigned long long)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 = (__le32 *)dind->b_data; - if (le32_to_cpu(data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)]) != gdblock) { - ext3_warning(sb, __func__, - "new group %u GDT block "E3FSBLK" not reserved", - 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 = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *), - GFP_NOFS); - if (!n_group_desc) { - err = -ENOMEM; - ext3_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 % EXT3_ADDR_PER_BLOCK(sb)] = 0; - err = ext3_journal_dirty_metadata(handle, dind); - if (err) - goto exit_group_desc; - brelse(dind); - dind = NULL; - inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9; - err = ext3_mark_iloc_dirty(handle, inode, &iloc); - if (err) - goto exit_group_desc; - memset((*primary)->b_data, 0, sb->s_blocksize); - err = ext3_journal_dirty_metadata(handle, *primary); - if (err) - goto exit_group_desc; - - 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); - - le16_add_cpu(&es->s_reserved_gdt_blocks, -1); - err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); - if (err) - goto exit_inode; - - return 0; - -exit_group_desc: - kfree(n_group_desc); -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; - ext3_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 = 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 = (__le32 *)dind->b_data + (EXT3_SB(sb)->s_gdb_count % - EXT3_ADDR_PER_BLOCK(sb)); - end = (__le32 *)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, __func__, - "reserved block "E3FSBLK - " 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 = 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 = (__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 = 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 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 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_sb(sb, 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); - if (unlikely(!bh)) { - err = -ENOMEM; - break; - } - ext3_debug("update metadata backup %#04lx\n", - (unsigned long)bh->b_blocknr); - if ((err = ext3_journal_get_write_access(handle, bh))) { - brelse(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); - err = ext3_journal_dirty_metadata(handle, bh); - brelse(bh); - if (err) - break; - } - 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, __func__, - "can't update backup for group %d (err %d), " - "forcing fsck on next reboot", 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; - 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, __func__, - "Can't resize non-sparse filesystem further"); - return -EPERM; - } - - if (le32_to_cpu(es->s_blocks_count) + input->blocks_count < - le32_to_cpu(es->s_blocks_count)) { - ext3_warning(sb, __func__, "blocks_count overflow\n"); - return -EINVAL; - } - - if (le32_to_cpu(es->s_inodes_count) + EXT3_INODES_PER_GROUP(sb) < - le32_to_cpu(es->s_inodes_count)) { - ext3_warning(sb, __func__, "inodes_count overflow\n"); - return -EINVAL; - } - - if (reserved_gdb || gdb_off == 0) { - if (!EXT3_HAS_COMPAT_FEATURE(sb, - EXT3_FEATURE_COMPAT_RESIZE_INODE) - || !le16_to_cpu(es->s_reserved_gdt_blocks)) { - ext3_warning(sb, __func__, - "No reserved GDT blocks, can't resize"); - return -EPERM; - } - inode = ext3_iget(sb, EXT3_RESIZE_INO); - if (IS_ERR(inode)) { - ext3_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 = ext3_journal_start_sb(sb, - ext3_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) { - ext3_warning(sb, __func__, - "multiple resizers run on filesystem!"); - err = -EBUSY; - 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; - - /* - * 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 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)); - - /* - * 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. - */ - le32_add_cpu(&es->s_blocks_count, input->blocks_count); - le32_add_cpu(&es->s_inodes_count, EXT3_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++; - - err = ext3_journal_dirty_metadata(handle, primary); - if (err) - goto exit_journal; - - /* Update the reserved block counts only once the new group is - * active. */ - le32_add_cpu(&es->s_r_blocks_count, 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, - EXT3_INODES_PER_GROUP(sb)); - - err = ext3_journal_dirty_metadata(handle, sbi->s_sbh); - -exit_journal: - mutex_unlock(&sbi->s_resize_lock); - if ((err2 = ext3_journal_stop(handle)) && !err) - err = err2; - if (!err) { - update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, - sizeof(struct ext3_super_block)); - update_backups(sb, primary->b_blocknr, primary->b_data, - primary->b_size); - } -exit_put: - 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, - ext3_fsblk_t n_blocks_count) -{ - ext3_fsblk_t o_blocks_count; - ext3_grpblk_t last; - ext3_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 the s_resize_lock below. */ - o_blocks_count = le32_to_cpu(es->s_blocks_count); - - if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG "EXT3-fs: extending last group from "E3FSBLK - " up to "E3FSBLK" 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 "EXT3-fs: filesystem on %s:" - " too large to resize to "E3FSBLK" blocks safely\n", - sb->s_id, n_blocks_count); - if (sizeof(sector_t) < 8) - ext3_warning(sb, __func__, - "CONFIG_LBDAF not enabled\n"); - return -EINVAL; - } - - if (n_blocks_count < o_blocks_count) { - ext3_warning(sb, __func__, - "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, __func__, - "need to use ext2online to resize further"); - return -EPERM; - } - - add = EXT3_BLOCKS_PER_GROUP(sb) - last; - - if (o_blocks_count + add < o_blocks_count) { - ext3_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) - ext3_warning(sb, __func__, - "will only finish group ("E3FSBLK - " 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, __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 ext3_free_blocks(). - */ - handle = ext3_journal_start_sb(sb, 3); - if (IS_ERR(handle)) { - err = PTR_ERR(handle); - ext3_warning(sb, __func__, "error %d on journal start",err); - goto exit_put; - } - - mutex_lock(&EXT3_SB(sb)->s_resize_lock); - if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) { - ext3_warning(sb, __func__, - "multiple resizers run on filesystem!"); - mutex_unlock(&EXT3_SB(sb)->s_resize_lock); - ext3_journal_stop(handle); - err = -EBUSY; - goto exit_put; - } - - if ((err = ext3_journal_get_write_access(handle, - EXT3_SB(sb)->s_sbh))) { - ext3_warning(sb, __func__, - "error %d on journal write access", err); - mutex_unlock(&EXT3_SB(sb)->s_resize_lock); - ext3_journal_stop(handle); - goto exit_put; - } - es->s_blocks_count = cpu_to_le32(o_blocks_count + add); - err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); - mutex_unlock(&EXT3_SB(sb)->s_resize_lock); - if (err) { - ext3_warning(sb, __func__, - "error %d on journal dirty metadata", err); - ext3_journal_stop(handle); - goto exit_put; - } - ext3_debug("freeing blocks "E3FSBLK" through "E3FSBLK"\n", - o_blocks_count, o_blocks_count + add); - ext3_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks); - ext3_debug("freed blocks "E3FSBLK" through "E3FSBLK"\n", - o_blocks_count, o_blocks_count + add); - if ((err = ext3_journal_stop(handle))) - goto exit_put; - if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG "EXT3-fs: extended group to %u blocks\n", - le32_to_cpu(es->s_blocks_count)); - update_backups(sb, EXT3_SB(sb)->s_sbh->b_blocknr, (char *)es, - sizeof(struct ext3_super_block)); -exit_put: - return err; -} /* ext3_group_extend */ |