diff options
Diffstat (limited to 'fs/ext4/resize.c')
| -rw-r--r-- | fs/ext4/resize.c | 1175 |
1 files changed, 886 insertions, 289 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 996780a..f9d948f 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -134,6 +134,172 @@ static int verify_group_input(struct super_block *sb, return err; } +/* + * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex + * group each time. + */ +struct ext4_new_flex_group_data { + struct ext4_new_group_data *groups; /* new_group_data for groups + in the flex group */ + __u16 *bg_flags; /* block group flags of groups + in @groups */ + ext4_group_t count; /* number of groups in @groups + */ +}; + +/* + * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of + * @flexbg_size. + * + * Returns NULL on failure otherwise address of the allocated structure. + */ +static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) +{ + struct ext4_new_flex_group_data *flex_gd; + + flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); + if (flex_gd == NULL) + goto out3; + + flex_gd->count = flexbg_size; + + flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) * + flexbg_size, GFP_NOFS); + if (flex_gd->groups == NULL) + goto out2; + + flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS); + if (flex_gd->bg_flags == NULL) + goto out1; + + return flex_gd; + +out1: + kfree(flex_gd->groups); +out2: + kfree(flex_gd); +out3: + return NULL; +} + +static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) +{ + kfree(flex_gd->bg_flags); + kfree(flex_gd->groups); + kfree(flex_gd); +} + +/* + * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps + * and inode tables for a flex group. + * + * This function is used by 64bit-resize. Note that this function allocates + * group tables from the 1st group of groups contained by @flexgd, which may + * be a partial of a flex group. + * + * @sb: super block of fs to which the groups belongs + */ +static void ext4_alloc_group_tables(struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd, + int flexbg_size) +{ + struct ext4_new_group_data *group_data = flex_gd->groups; + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + ext4_fsblk_t start_blk; + ext4_fsblk_t last_blk; + ext4_group_t src_group; + ext4_group_t bb_index = 0; + ext4_group_t ib_index = 0; + ext4_group_t it_index = 0; + ext4_group_t group; + ext4_group_t last_group; + unsigned overhead; + + BUG_ON(flex_gd->count == 0 || group_data == NULL); + + src_group = group_data[0].group; + last_group = src_group + flex_gd->count - 1; + + BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != + (last_group & ~(flexbg_size - 1)))); +next_group: + group = group_data[0].group; + start_blk = ext4_group_first_block_no(sb, src_group); + last_blk = start_blk + group_data[src_group - group].blocks_count; + + overhead = ext4_bg_has_super(sb, src_group) ? + (1 + ext4_bg_num_gdb(sb, src_group) + + le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; + + start_blk += overhead; + + BUG_ON(src_group >= group_data[0].group + flex_gd->count); + /* We collect contiguous blocks as much as possible. */ + src_group++; + for (; src_group <= last_group; src_group++) + if (!ext4_bg_has_super(sb, src_group)) + last_blk += group_data[src_group - group].blocks_count; + else + break; + + /* Allocate block bitmaps */ + for (; bb_index < flex_gd->count; bb_index++) { + if (start_blk >= last_blk) + goto next_group; + group_data[bb_index].block_bitmap = start_blk++; + ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL); + group -= group_data[0].group; + group_data[group].free_blocks_count--; + if (flexbg_size > 1) + flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; + } + + /* Allocate inode bitmaps */ + for (; ib_index < flex_gd->count; ib_index++) { + if (start_blk >= last_blk) + goto next_group; + group_data[ib_index].inode_bitmap = start_blk++; + ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL); + group -= group_data[0].group; + group_data[group].free_blocks_count--; + if (flexbg_size > 1) + flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; + } + + /* Allocate inode tables */ + for (; it_index < flex_gd->count; it_index++) { + if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk) + goto next_group; + group_data[it_index].inode_table = start_blk; + ext4_get_group_no_and_offset(sb, start_blk, &group, NULL); + group -= group_data[0].group; + group_data[group].free_blocks_count -= + EXT4_SB(sb)->s_itb_per_group; + if (flexbg_size > 1) + flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; + + start_blk += EXT4_SB(sb)->s_itb_per_group; + } + + if (test_opt(sb, DEBUG)) { + int i; + group = group_data[0].group; + + printk(KERN_DEBUG "EXT4-fs: adding a flex group with " + "%d groups, flexbg size is %d:\n", flex_gd->count, + flexbg_size); + + for (i = 0; i < flex_gd->count; i++) { + printk(KERN_DEBUG "adding %s group %u: %u " + "blocks (%d free)\n", + ext4_bg_has_super(sb, group + i) ? "normal" : + "no-super", group + i, + group_data[i].blocks_count, + group_data[i].free_blocks_count); + } + } +} + static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, ext4_fsblk_t blk) { @@ -179,131 +345,250 @@ static int extend_or_restart_transaction(handle_t *handle, int thresh) } /* - * Set up the block and inode bitmaps, and the inode table for the new group. + * set_flexbg_block_bitmap() mark @count blocks starting from @block used. + * + * Helper function for ext4_setup_new_group_blocks() which set . + * + * @sb: super block + * @handle: journal handle + * @flex_gd: flex group data + */ +static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, + struct ext4_new_flex_group_data *flex_gd, + ext4_fsblk_t block, ext4_group_t count) +{ + ext4_group_t count2; + + ext4_debug("mark blocks [%llu/%u] used\n", block, count); + for (count2 = count; count > 0; count -= count2, block += count2) { + ext4_fsblk_t start; + struct buffer_head *bh; + ext4_group_t group; + int err; + + ext4_get_group_no_and_offset(sb, block, &group, NULL); + start = ext4_group_first_block_no(sb, group); + group -= flex_gd->groups[0].group; + + count2 = sb->s_blocksize * 8 - (block - start); + if (count2 > count) + count2 = count; + + if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { + BUG_ON(flex_gd->count > 1); + continue; + } + + err = extend_or_restart_transaction(handle, 1); + if (err) + return err; + + bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); + if (!bh) + return -EIO; + + err = ext4_journal_get_write_access(handle, bh); + if (err) + return err; + ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block, + block - start, count2); + ext4_set_bits(bh->b_data, block - start, count2); + + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (unlikely(err)) + return err; + brelse(bh); + } + + return 0; +} + +/* + * Set up the block and inode bitmaps, and the inode table for the new groups. * 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. + * + * setup_new_flex_group_blocks handles a flex group as follow: + * 1. copy super block and GDT, and initialize group tables if necessary. + * In this step, we only set bits in blocks bitmaps for blocks taken by + * super block and GDT. + * 2. allocate group tables in block bitmaps, that is, set bits in block + * bitmap for blocks taken by group tables. */ -static int setup_new_group_blocks(struct super_block *sb, - struct ext4_new_group_data *input) +static int setup_new_flex_group_blocks(struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd) { + int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; + ext4_fsblk_t start; + ext4_fsblk_t block; 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; + struct ext4_super_block *es = sbi->s_es; + struct ext4_new_group_data *group_data = flex_gd->groups; + __u16 *bg_flags = flex_gd->bg_flags; handle_t *handle; - ext4_fsblk_t block; - ext4_grpblk_t bit; - int i; - int err = 0, err2; + ext4_group_t group, count; + struct buffer_head *bh = NULL; + int reserved_gdb, i, j, err = 0, err2; + + BUG_ON(!flex_gd->count || !group_data || + group_data[0].group != sbi->s_groups_count); + + reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); /* 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); - BUG_ON(input->group != sbi->s_groups_count); + group = group_data[0].group; + for (i = 0; i < flex_gd->count; i++, group++) { + unsigned long gdblocks; - /* 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; + gdblocks = ext4_bg_num_gdb(sb, group); + start = ext4_group_first_block_no(sb, group); - ext4_debug("update backup group %#04llx (+%d)\n", block, bit); - err = extend_or_restart_transaction(handle, 1); - if (err) - goto exit_journal; + /* Copy all of the GDT blocks into the backup in this group */ + for (j = 0, block = start + 1; j < gdblocks; j++, block++) { + struct buffer_head *gdb; - gdb = sb_getblk(sb, block); - if (!gdb) { - err = -EIO; - goto exit_journal; - } - if ((err = ext4_journal_get_write_access(handle, gdb))) { + ext4_debug("update backup group %#04llx\n", block); + err = extend_or_restart_transaction(handle, 1); + if (err) + goto out; + + gdb = sb_getblk(sb, block); + if (!gdb) { + err = -EIO; + goto out; + } + + err = ext4_journal_get_write_access(handle, gdb); + if (err) { + brelse(gdb); + goto out; + } + memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data, + gdb->b_size); + set_buffer_uptodate(gdb); + + err = ext4_handle_dirty_metadata(handle, NULL, gdb); + if (unlikely(err)) { + brelse(gdb); + goto out; + } brelse(gdb); - goto exit_journal; } - memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size); - set_buffer_uptodate(gdb); - err = ext4_handle_dirty_metadata(handle, NULL, gdb); - if (unlikely(err)) { - brelse(gdb); - goto exit_journal; + + /* Zero out all of the reserved backup group descriptor + * table blocks + */ + if (ext4_bg_has_super(sb, group)) { + err = sb_issue_zeroout(sb, gdblocks + start + 1, + reserved_gdb, GFP_NOFS); + if (err) + goto out; } - brelse(gdb); - } - /* Zero out all of the reserved backup group descriptor table blocks */ - ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", - block, sbi->s_itb_per_group); - err = sb_issue_zeroout(sb, gdblocks + start + 1, reserved_gdb, - GFP_NOFS); - if (err) - goto exit_journal; + /* Initialize group tables of the grop @group */ + if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) + goto handle_bb; - err = extend_or_restart_transaction(handle, 2); - if (err) - goto exit_journal; + /* Zero out all of the inode table blocks */ + block = group_data[i].inode_table; + ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", + block, sbi->s_itb_per_group); + err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, + GFP_NOFS); + if (err) + goto out; - bh = bclean(handle, sb, input->block_bitmap); - if (IS_ERR(bh)) { - err = PTR_ERR(bh); - goto exit_journal; - } +handle_bb: + if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) + goto handle_ib; - if (ext4_bg_has_super(sb, input->group)) { - ext4_debug("mark backup group tables %#04llx (+0)\n", start); - ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb + 1); - } + /* Initialize block bitmap of the @group */ + block = group_data[i].block_bitmap; + err = extend_or_restart_transaction(handle, 1); + if (err) + goto out; - 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 */ - block = input->inode_table; - ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", - block, sbi->s_itb_per_group); - err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, GFP_NOFS); - if (err) - goto exit_bh; - ext4_set_bits(bh->b_data, input->inode_table - start, - sbi->s_itb_per_group); + bh = bclean(handle, sb, block); + if (IS_ERR(bh)) { + err = PTR_ERR(bh); + goto out; + } + if (ext4_bg_has_super(sb, group)) { + ext4_debug("mark backup superblock %#04llx (+0)\n", + start); + ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb + + 1); + } + ext4_mark_bitmap_end(group_data[i].blocks_count, + sb->s_blocksize * 8, bh->b_data); + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + goto out; + brelse(bh); +handle_ib: + if (bg_flags[i] & EXT4_BG_INODE_UNINIT) + continue; - ext4_mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8, - bh->b_data); - err = ext4_handle_dirty_metadata(handle, NULL, bh); - if (unlikely(err)) { - ext4_std_error(sb, err); - goto exit_bh; + /* Initialize inode bitmap of the @group */ + block = group_data[i].inode_bitmap; + err = extend_or_restart_transaction(handle, 1); + if (err) + goto out; + /* Mark unused entries in inode bitmap used */ + bh = bclean(handle, sb, block); + if (IS_ERR(bh)) { + err = PTR_ERR(bh); + goto out; + } + + ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), + sb->s_blocksize * 8, bh->b_data); + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + goto out; + brelse(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; + bh = NULL; + + /* Mark group tables in block bitmap */ + for (j = 0; j < GROUP_TABLE_COUNT; j++) { + count = group_table_count[j]; + start = (&group_data[0].block_bitmap)[j]; + block = start; + for (i = 1; i < flex_gd->count; i++) { + block += group_table_count[j]; + if (block == (&group_data[i].block_bitmap)[j]) { + count += group_table_count[j]; + continue; + } + err = set_flexbg_block_bitmap(sb, handle, + flex_gd, start, count); + if (err) + goto out; + count = group_table_count[j]; + start = group_data[i].block_bitmap; + block = start; + } + + if (count) { + err = set_flexbg_block_bitmap(sb, handle, + flex_gd, start, count); + if (err) + goto out; + } } - ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8, - bh->b_data); - err = ext4_handle_dirty_metadata(handle, NULL, bh); - if (unlikely(err)) - ext4_std_error(sb, err); -exit_bh: +out: brelse(bh); - -exit_journal: - if ((err2 = ext4_journal_stop(handle)) && !err) + err2 = ext4_journal_stop(handle); + if (err2 && !err) err = err2; return err; @@ -351,10 +636,10 @@ static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, * groups in current filesystem that have BACKUPS, or -ve error code. */ static int verify_reserved_gdb(struct super_block *sb, + ext4_group_t end, 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; @@ -429,7 +714,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, if (!gdb_bh) return -EIO; - gdbackups = verify_reserved_gdb(sb, gdb_bh); + gdbackups = verify_reserved_gdb(sb, group, gdb_bh); if (gdbackups < 0) { err = gdbackups; goto exit_bh; @@ -592,7 +877,8 @@ static int reserve_backup_gdb(handle_t *handle, struct inode *inode, err = -EIO; goto exit_bh; } - if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) { + gdbackups = verify_reserved_gdb(sb, group, primary[res]); + if (gdbackups < 0) { brelse(primary[res]); err = gdbackups; goto exit_bh; @@ -735,6 +1021,348 @@ exit_err: } } +/* + * ext4_add_new_descs() adds @count group descriptor of groups + * starting at @group + * + * @handle: journal handle + * @sb: super block + * @group: the group no. of the first group desc to be added + * @resize_inode: the resize inode + * @count: number of group descriptors to be added + */ +static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, + ext4_group_t group, struct inode *resize_inode, + ext4_group_t count) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + struct buffer_head *gdb_bh; + int i, gdb_off, gdb_num, err = 0; + + for (i = 0; i < count; i++, group++) { + int reserved_gdb = ext4_bg_has_super(sb, group) ? + le16_to_cpu(es->s_reserved_gdt_blocks) : 0; + + gdb_off = group % EXT4_DESC_PER_BLOCK(sb); + gdb_num = group / EXT4_DESC_PER_BLOCK(sb); + + /* + * 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) { + gdb_bh = sbi->s_group_desc[gdb_num]; + err = ext4_journal_get_write_access(handle, gdb_bh); + + if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) + err = reserve_backup_gdb(handle, resize_inode, group); + } else + err = add_new_gdb(handle, resize_inode, group); + if (err) + break; + } + return err; +} + +/* + * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg + */ +static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd) +{ + struct ext4_new_group_data *group_data = flex_gd->groups; + struct ext4_group_desc *gdp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *gdb_bh; + ext4_group_t group; + __u16 *bg_flags = flex_gd->bg_flags; + int i, gdb_off, gdb_num, err = 0; + + + for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { + group = group_data->group; + + gdb_off = group % EXT4_DESC_PER_BLOCK(sb); + gdb_num = group / EXT4_DESC_PER_BLOCK(sb); + + /* + * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). + */ + gdb_bh = sbi->s_group_desc[gdb_num]; + /* Update group descriptor block for new group */ + gdp = (struct ext4_group_desc *)((char *)gdb_bh->b_data + + gdb_off * EXT4_DESC_SIZE(sb)); + + memset(gdp, 0, EXT4_DESC_SIZE(sb)); + ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); + ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); + ext4_inode_table_set(sb, gdp, group_data->inode_table); + ext4_free_group_clusters_set(sb, gdp, + EXT4_B2C(sbi, group_data->free_blocks_count)); + ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); + gdp->bg_flags = cpu_to_le16(*bg_flags); + gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); + + err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); + if (unlikely(err)) { + ext4_std_error(sb, err); + break; + } + + /* + * We can allocate memory for mb_alloc based on the new group + * descriptor + */ + err = ext4_mb_add_groupinfo(sb, group, gdp); + if (err) + break; + } + return err; +} + +/* + * ext4_update_super() updates the super block so that the newly added + * groups can be seen by the filesystem. + * + * @sb: super block + * @flex_gd: new added groups + */ +static void ext4_update_super(struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd) +{ + ext4_fsblk_t blocks_count = 0; + ext4_fsblk_t free_blocks = 0; + ext4_fsblk_t reserved_blocks = 0; + struct ext4_new_group_data *group_data = flex_gd->groups; + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + int i; + + BUG_ON(flex_gd->count == 0 || group_data == NULL); + /* + * 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. + */ + for (i = 0; i < flex_gd->count; i++) { + blocks_count += group_data[i].blocks_count; + free_blocks += group_data[i].free_blocks_count; + } + + reserved_blocks = ext4_r_blocks_count(es) * 100; + do_div(reserved_blocks, ext4_blocks_count(es)); + reserved_blocks *= blocks_count; + do_div(reserved_blocks, 100); + + ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); + le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * + flex_gd->count); + + /* + * We need to protect s_groups_count against other CPUs seeing + * inconsistent state in the superblock. + * + * The precise rules we use are: + * + * * Writers must perform a smp_wmb() after updating all + * dependent data and before modifying the groups count + * + * * 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 += flex_gd->count; + + /* Update the reserved block counts only once the new group is + * active. */ + ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + + reserved_blocks); + + /* Update the free space counts */ + percpu_counter_add(&sbi->s_freeclusters_counter, + EXT4_B2C(sbi, free_blocks)); + percpu_counter_add(&sbi->s_freeinodes_counter, + EXT4_INODES_PER_GROUP(sb) * flex_gd->count); + + if (EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_FLEX_BG) && + sbi->s_log_groups_per_flex) { + ext4_group_t flex_group; + flex_group = ext4_flex_group(sbi, group_data[0].group); + atomic_add(EXT4_B2C(sbi, free_blocks), + &sbi->s_flex_groups[flex_group].free_clusters); + atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, + &sbi->s_flex_groups[flex_group].free_inodes); + } + + if (test_opt(sb, DEBUG)) + printk(KERN_DEBUG "EXT4-fs: added group %u:" + "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, + blocks_count, free_blocks, reserved_blocks); +} + +/* Add a flex group to an fs. 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. + */ +static int ext4_flex_group_add(struct super_block *sb, + struct inode *resize_inode, + struct ext4_new_flex_group_data *flex_gd) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + ext4_fsblk_t o_blocks_count; + ext4_grpblk_t last; + ext4_group_t group; + handle_t *handle; + unsigned reserved_gdb; + int err = 0, err2 = 0, credit; + + BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); + + reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); + o_blocks_count = ext4_blocks_count(es); + ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); + BUG_ON(last); + + err = setup_new_flex_group_blocks(sb, flex_gd); + if (err) + goto exit; + /* + * We will always be modifying at least the superblock and 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. + */ + credit = flex_gd->count * 4 + reserved_gdb; + handle = ext4_journal_start_sb(sb, credit); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + goto exit; + } + + err = ext4_journal_get_write_access(handle, sbi->s_sbh); + if (err) + goto exit_journal; + + group = flex_gd->groups[0].group; + BUG_ON(group != EXT4_SB(sb)->s_groups_count); + err = ext4_add_new_descs(handle, sb, group, + resize_inode, flex_gd->count); + if (err) + goto exit_journal; + + err = ext4_setup_new_descs(handle, sb, flex_gd); + if (err) + goto exit_journal; + + ext4_update_super(sb, flex_gd); + + err = ext4_handle_dirty_super(handle, sb); + +exit_journal: + err2 = ext4_journal_stop(handle); + if (!err) + err = err2; + + if (!err) { + int i; + update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, + sizeof(struct ext4_super_block)); + for (i = 0; i < flex_gd->count; i++, group++) { + struct buffer_head *gdb_bh; + int gdb_num; + gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb); + gdb_bh = sbi->s_group_desc[gdb_num]; + update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, + gdb_bh->b_size); + } + } +exit: + return err; +} + +static int ext4_setup_next_flex_gd(struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd, + ext4_fsblk_t n_blocks_count, + unsigned long flexbg_size) +{ + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + struct ext4_new_group_data *group_data = flex_gd->groups; + ext4_fsblk_t o_blocks_count; + ext4_group_t n_group; + ext4_group_t group; + ext4_group_t last_group; + ext4_grpblk_t last; + ext4_grpblk_t blocks_per_group; + unsigned long i; + + blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb); + + o_blocks_count = ext4_blocks_count(es); + + if (o_blocks_count == n_blocks_count) + return 0; + + ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); + BUG_ON(last); + ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); + + last_group = group | (flexbg_size - 1); + if (last_group > n_group) + last_group = n_group; + + flex_gd->count = last_group - group + 1; + + for (i = 0; i < flex_gd->count; i++) { + int overhead; + + group_data[i].group = group + i; + group_data[i].blocks_count = blocks_per_group; + overhead = ext4_bg_has_super(sb, group + i) ? + (1 + ext4_bg_num_gdb(sb, group + i) + + le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; + group_data[i].free_blocks_count = blocks_per_group - overhead; + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | + EXT4_BG_INODE_UNINIT; + else + flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; + } + + if (last_group == n_group && + EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + /* We need to initialize block bitmap of last group. */ + flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; + + if ((last_group == n_group) && (last != blocks_per_group - 1)) { + group_data[i - 1].blocks_count = last + 1; + group_data[i - 1].free_blocks_count -= blocks_per_group- + last - 1; + } + + return 1; +} + /* 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 @@ -750,16 +1378,15 @@ exit_err: */ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) { + struct ext4_new_flex_group_data flex_gd; 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; + int err; + __u16 bg_flags = 0; gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb); gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); @@ -798,175 +1425,69 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) } - if ((err = verify_group_input(sb, input))) - goto exit_put; + err = verify_group_input(sb, input); + if (err) + goto out; - if ((err = setup_new_group_blocks(sb, input))) - goto exit_put; + flex_gd.count = 1; + flex_gd.groups = input; + flex_gd.bg_flags = &bg_flags; + err = ext4_flex_group_add(sb, inode, &flex_gd); +out: + iput(inode); + return err; +} /* ext4_group_add */ - /* - * 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. +/* + * extend a group without checking assuming that checking has been done. + */ +static int ext4_group_extend_no_check(struct super_block *sb, + ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) +{ + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + handle_t *handle; + int err = 0, err2; + + /* We will update the superblock, one block bitmap, and + * one group descriptor via ext4_group_add_blocks(). */ - handle = ext4_journal_start_sb(sb, - ext4_bg_has_super(sb, input->group) ? - 3 + reserved_gdb : 4); + handle = ext4_journal_start_sb(sb, 3); if (IS_ERR(handle)) { err = PTR_ERR(handle); - goto exit_put; + ext4_warning(sb, "error %d on journal start", err); + return err; } - 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->group); - if (err) - goto exit_journal; - } - } else { - /* - * Note that we can access new group descriptor block safely - * only if add_new_gdb() succeeds. - */ - err = add_new_gdb(handle, inode, input->group); - if (err) - goto exit_journal; - primary = sbi->s_group_desc[gdb_num]; + err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); + if (err) { + ext4_warning(sb, "error %d on journal write access", err); + goto errout; } - /* - * OK, now we've set up the new group. Time to make it active. - * - * so we have to be safe wrt. concurrent accesses the group - * data. So we need to be careful to set all of the relevant - * group descriptor data etc. *before* we enable the group. - * - * The key field here is sbi->s_groups_count: as long as - * that retains its old value, nobody is going to access the new - * group. - * - * So first we update all the descriptor metadata for the new - * group; then we update the total disk blocks count; then we - * update the groups count to enable the group; then finally we - * update the free space counts so that the system can start - * using the new disk blocks. - */ - - /* Update group descriptor block for new group */ - gdp = (struct ext4_group_desc *)((char *)primary->b_data + - gdb_off * EXT4_DESC_SIZE(sb)); - - memset(gdp, 0, EXT4_DESC_SIZE(sb)); - ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */ - ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */ - ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */ - ext4_free_group_clusters_set(sb, gdp, input->free_blocks_count); - ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); - gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED); - gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); - - /* - * We can allocate memory for mb_alloc based on the new group - * descriptor - */ - err = ext4_mb_add_groupinfo(sb, input->group, gdp); + ext4_blocks_count_set(es, o_blocks_count + add); + ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, + o_blocks_count + add); + /* We add the blocks to the bitmap and set the group need init bit */ + err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); if (err) - goto exit_journal; - - /* - * Make the new blocks and inodes valid next. We do this before - * increasing the group count so that once the group is enabled, - * all of its blocks and inodes are already valid. - * - * We always allocate group-by-group, then block-by-block or - * inode-by-inode within a group, so enabling these - * blocks/inodes before the group is live won't actually let us - * allocate the new space yet. - */ - ext4_blocks_count_set(es, ext4_blocks_count(es) + - input->blocks_count); - le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb)); - - /* - * We need to protect s_groups_count against other CPUs seeing - * inconsistent state in the superblock. - * - * The precise rules we use are: - * - * * Writers must perform a smp_wmb() after updating all dependent - * data and before modifying the groups count - * - * * 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 = ext4_handle_dirty_metadata(handle, NULL, primary); - if (unlikely(err)) { - ext4_std_error(sb, err); - goto exit_journal; - } - - /* 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_freeclusters_counter, - EXT4_B2C(sbi, input->free_blocks_count)); - percpu_counter_add(&sbi->s_freeinodes_counter, - EXT4_INODES_PER_GROUP(sb)); - - if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) && - sbi->s_log_groups_per_flex) { - ext4_group_t flex_group; - flex_group = ext4_flex_group(sbi, input->group); - atomic_add(EXT4_B2C(sbi, input->free_blocks_count), - &sbi->s_flex_groups[flex_group].free_clusters); - atomic_add(EXT4_INODES_PER_GROUP(sb), - &sbi->s_flex_groups[flex_group].free_inodes); - } - + goto errout; ext4_handle_dirty_super(handle, sb); - -exit_journal: - if ((err2 = ext4_journal_stop(handle)) && !err) + ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, + o_blocks_count + add); +errout: + err2 = ext4_journal_stop(handle); + if (err2 && !err) err = err2; - if (!err && primary) { - update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, + + if (!err) { + 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)); - 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 @@ -985,8 +1506,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, ext4_grpblk_t last; ext4_grpblk_t add; struct buffer_head *bh; - handle_t *handle; - int err, err2; + int err; ext4_group_t group; o_blocks_count = ext4_blocks_count(es); @@ -1042,42 +1562,119 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, } brelse(bh); - /* We will update the superblock, one block bitmap, and - * one group descriptor via ext4_free_blocks(). - */ - handle = ext4_journal_start_sb(sb, 3); - if (IS_ERR(handle)) { - err = PTR_ERR(handle); - ext4_warning(sb, "error %d on journal start", err); - goto exit_put; + err = ext4_group_extend_no_check(sb, o_blocks_count, add); + return err; +} /* ext4_group_extend */ + +/* + * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count + * + * @sb: super block of the fs to be resized + * @n_blocks_count: the number of blocks resides in the resized fs + */ +int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) +{ + struct ext4_new_flex_group_data *flex_gd = NULL; + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + struct buffer_head *bh; + struct inode *resize_inode; + ext4_fsblk_t o_blocks_count; + ext4_group_t o_group; + ext4_group_t n_group; + ext4_grpblk_t offset; + unsigned long n_desc_blocks; + unsigned long o_desc_blocks; + unsigned long desc_blocks; + int err = 0, flexbg_size = 1; + + o_blocks_count = ext4_blocks_count(es); + + if (test_opt(sb, DEBUG)) + printk(KERN_DEBUG "EXT4-fs: resizing filesystem from %llu " + "upto %llu blocks\n", o_blocks_count, n_blocks_count); + + if (n_blocks_count < o_blocks_count) { + /* On-line shrinking not supported */ + ext4_warning(sb, "can't shrink FS - resize aborted"); + return -EINVAL; } - if ((err = ext4_journal_get_write_access(handle, - EXT4_SB(sb)->s_sbh))) { - ext4_warning(sb, "error %d on journal write access", err); - ext4_journal_stop(handle); - goto exit_put; + if (n_blocks_count == o_blocks_count) + /* Nothing need to do */ + return 0; + + ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset); + ext4_get_group_no_and_offset(sb, o_blocks_count, &o_group, &offset); + + n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) / + EXT4_DESC_PER_BLOCK(sb); + o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) / + EXT4_DESC_PER_BLOCK(sb); + desc_blocks = n_desc_blocks - o_desc_blocks; + + if (desc_blocks && + (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) || + le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) { + ext4_warning(sb, "No reserved GDT blocks, can't resize"); + return -EPERM; } - ext4_blocks_count_set(es, o_blocks_count + add); - ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, - o_blocks_count + add); - /* We add the blocks to the bitmap and set the group need init bit */ - err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); - ext4_handle_dirty_super(handle, sb); - ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, - o_blocks_count + add); - err2 = ext4_journal_stop(handle); - if (!err && err2) - err = err2; - if (err) - goto exit_put; + resize_inode = ext4_iget(sb, EXT4_RESIZE_INO); + if (IS_ERR(resize_inode)) { + ext4_warning(sb, "Error opening resize inode"); + return PTR_ERR(resize_inode); + } + /* See if the device is actually as big as what was requested */ + bh = sb_bread(sb, n_blocks_count - 1); + if (!bh) { + ext4_warning(sb, "can't read last block, resize aborted"); + return -ENOSPC; + } + brelse(bh); + + if (offset != 0) { + /* extend the last group */ + ext4_grpblk_t add; + add = EXT4_BLOCKS_PER_GROUP(sb) - offset; + err = ext4_group_extend_no_check(sb, o_blocks_count, add); + if (err) + goto out; + } + + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) && + es->s_log_groups_per_flex) + flexbg_size = 1 << es->s_log_groups_per_flex; + + o_blocks_count = ext4_blocks_count(es); + if (o_blocks_count == n_blocks_count) + goto out; + + flex_gd = alloc_flex_gd(flexbg_size); + if (flex_gd == NULL) { + err = -ENOMEM; + goto out; + } + + /* Add flex groups. Note that a regular group is a + * flex group with 1 group. + */ + while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, + flexbg_size)) { + ext4_alloc_group_tables(sb, flex_gd, flexbg_size); + err = ext4_flex_group_add(sb, resize_inode, flex_gd); + if (unlikely(err)) + break; + } + +out: + if (flex_gd) + free_flex_gd(flex_gd); + + iput(resize_inode); 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: + printk(KERN_DEBUG "EXT4-fs: resized filesystem from %llu " + "upto %llu blocks\n", o_blocks_count, n_blocks_count); return err; -} /* ext4_group_extend */ +} |
