--- /dev/null
+/*
+ * linux/fs/ext4/resize.c
+ *
+ * Support for resizing an ext4 filesystem while it is mounted.
+ *
+ * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
+ *
+ * This could probably be made into a module, because it is not often in use.
+ */
+
+
+#define EXT4FS_DEBUG
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+
+#include "ext4_jbd2.h"
+
+int ext4_resize_begin(struct super_block *sb)
+{
+ int ret = 0;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ /*
+ * If we are not using the primary superblock/GDT copy don't resize,
+ * because the user tools have no way of handling this. Probably a
+ * bad time to do it anyways.
+ */
+ if (EXT4_SB(sb)->s_sbh->b_blocknr !=
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
+ ext4_warning(sb, "won't resize using backup superblock at %llu",
+ (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
+ return -EPERM;
+ }
+
+ /*
+ * We are not allowed to do online-resizing on a filesystem mounted
+ * with error, because it can destroy the filesystem easily.
+ */
+ if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
+ ext4_warning(sb, "There are errors in the filesystem, "
+ "so online resizing is not allowed\n");
+ return -EPERM;
+ }
+
+ if (test_and_set_bit_lock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags))
+ ret = -EBUSY;
+
+ return ret;
+}
+
+void ext4_resize_end(struct super_block *sb)
+{
+ clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags);
+ smp_mb__after_atomic();
+}
+
+static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb,
+ ext4_group_t group) {
+ return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) <<
+ EXT4_DESC_PER_BLOCK_BITS(sb);
+}
+
+static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb,
+ ext4_group_t group) {
+ group = ext4_meta_bg_first_group(sb, group);
+ return ext4_group_first_block_no(sb, group);
+}
+
+static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
+ ext4_group_t group) {
+ ext4_grpblk_t overhead;
+ overhead = ext4_bg_num_gdb(sb, group);
+ if (ext4_bg_has_super(sb, group))
+ overhead += 1 +
+ le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
+ return overhead;
+}
+
+#define outside(b, first, last) ((b) < (first) || (b) >= (last))
+#define inside(b, first, last) ((b) >= (first) && (b) < (last))
+
+static int verify_group_input(struct super_block *sb,
+ struct ext4_new_group_data *input)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ ext4_fsblk_t start = ext4_blocks_count(es);
+ ext4_fsblk_t end = start + input->blocks_count;
+ ext4_group_t group = input->group;
+ ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
+ unsigned overhead;
+ ext4_fsblk_t metaend;
+ struct buffer_head *bh = NULL;
+ ext4_grpblk_t free_blocks_count, offset;
+ int err = -EINVAL;
+
+ if (group != sbi->s_groups_count) {
+ ext4_warning(sb, "Cannot add at group %u (only %u groups)",
+ input->group, sbi->s_groups_count);
+ return -EINVAL;
+ }
+
+ overhead = ext4_group_overhead_blocks(sb, group);
+ metaend = start + overhead;
+ input->free_blocks_count = free_blocks_count =
+ input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
+
+ if (test_opt(sb, DEBUG))
+ printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
+ "(%d free, %u reserved)\n",
+ ext4_bg_has_super(sb, input->group) ? "normal" :
+ "no-super", input->group, input->blocks_count,
+ free_blocks_count, input->reserved_blocks);
+
+ ext4_get_group_no_and_offset(sb, start, NULL, &offset);
+ if (offset != 0)
+ ext4_warning(sb, "Last group not full");
+ else if (input->reserved_blocks > input->blocks_count / 5)
+ ext4_warning(sb, "Reserved blocks too high (%u)",
+ input->reserved_blocks);
+ else if (free_blocks_count < 0)
+ ext4_warning(sb, "Bad blocks count %u",
+ input->blocks_count);
+ else if (!(bh = sb_bread(sb, end - 1)))
+ ext4_warning(sb, "Cannot read last block (%llu)",
+ end - 1);
+ else if (outside(input->block_bitmap, start, end))
+ ext4_warning(sb, "Block bitmap not in group (block %llu)",
+ (unsigned long long)input->block_bitmap);
+ else if (outside(input->inode_bitmap, start, end))
+ ext4_warning(sb, "Inode bitmap not in group (block %llu)",
+ (unsigned long long)input->inode_bitmap);
+ else if (outside(input->inode_table, start, end) ||
+ outside(itend - 1, start, end))
+ ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
+ (unsigned long long)input->inode_table, itend - 1);
+ else if (input->inode_bitmap == input->block_bitmap)
+ ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
+ (unsigned long long)input->block_bitmap);
+ else if (inside(input->block_bitmap, input->inode_table, itend))
+ ext4_warning(sb, "Block bitmap (%llu) in inode table "
+ "(%llu-%llu)",
+ (unsigned long long)input->block_bitmap,
+ (unsigned long long)input->inode_table, itend - 1);
+ else if (inside(input->inode_bitmap, input->inode_table, itend))
+ ext4_warning(sb, "Inode bitmap (%llu) in inode table "
+ "(%llu-%llu)",
+ (unsigned long long)input->inode_bitmap,
+ (unsigned long long)input->inode_table, itend - 1);
+ else if (inside(input->block_bitmap, start, metaend))
+ ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
+ (unsigned long long)input->block_bitmap,
+ start, metaend - 1);
+ else if (inside(input->inode_bitmap, start, metaend))
+ ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
+ (unsigned long long)input->inode_bitmap,
+ start, metaend - 1);
+ else if (inside(input->inode_table, start, metaend) ||
+ inside(itend - 1, start, metaend))
+ ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
+ "(%llu-%llu)",
+ (unsigned long long)input->inode_table,
+ itend - 1, start, metaend - 1);
+ else
+ err = 0;
+ brelse(bh);
+
+ return err;
+}
+
+/*
+ * 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;
+
+ if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
+ goto out2;
+ 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
+ *
+ * Returns 0 on a successful allocation of the metadata blocks in the
+ * block group.
+ */
+static int 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;
+ 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;
+ __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
+
+ 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;
+ if (src_group >= group_data[0].group + flex_gd->count)
+ return -ENOSPC;
+ start_blk = ext4_group_first_block_no(sb, src_group);
+ last_blk = start_blk + group_data[src_group - group].blocks_count;
+
+ overhead = ext4_group_overhead_blocks(sb, src_group);
+
+ start_blk += overhead;
+
+ /* We collect contiguous blocks as much as possible. */
+ src_group++;
+ for (; src_group <= last_group; src_group++) {
+ overhead = ext4_group_overhead_blocks(sb, src_group);
+ if (overhead == 0)
+ 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++;
+ group = ext4_get_group_number(sb, start_blk - 1);
+ group -= group_data[0].group;
+ group_data[group].free_blocks_count--;
+ flex_gd->bg_flags[group] &= uninit_mask;
+ }
+
+ /* 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++;
+ group = ext4_get_group_number(sb, start_blk - 1);
+ group -= group_data[0].group;
+ group_data[group].free_blocks_count--;
+ flex_gd->bg_flags[group] &= uninit_mask;
+ }
+
+ /* Allocate inode tables */
+ for (; it_index < flex_gd->count; it_index++) {
+ unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
+ ext4_fsblk_t next_group_start;
+
+ if (start_blk + itb > last_blk)
+ goto next_group;
+ group_data[it_index].inode_table = start_blk;
+ group = ext4_get_group_number(sb, start_blk);
+ next_group_start = ext4_group_first_block_no(sb, group + 1);
+ group -= group_data[0].group;
+
+ if (start_blk + itb > next_group_start) {
+ flex_gd->bg_flags[group + 1] &= uninit_mask;
+ overhead = start_blk + itb - next_group_start;
+ group_data[group + 1].free_blocks_count -= overhead;
+ itb -= overhead;
+ }
+
+ group_data[group].free_blocks_count -= itb;
+ flex_gd->bg_flags[group] &= uninit_mask;
+ 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);
+ }
+ }
+ return 0;
+}
+
+static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
+ ext4_fsblk_t blk)
+{
+ struct buffer_head *bh;
+ int err;
+
+ bh = sb_getblk(sb, blk);
+ if (unlikely(!bh))
+ return ERR_PTR(-ENOMEM);
+ BUFFER_TRACE(bh, "get_write_access");
+ if ((err = ext4_journal_get_write_access(handle, bh))) {
+ brelse(bh);
+ bh = ERR_PTR(err);
+ } else {
+ memset(bh->b_data, 0, sb->s_blocksize);
+ set_buffer_uptodate(bh);
+ }
+
+ return bh;
+}
+
+/*
+ * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
+ * If that fails, restart the transaction & regain write access for the
+ * buffer head which is used for block_bitmap modifications.
+ */
+static int extend_or_restart_transaction(handle_t *handle, int thresh)
+{
+ int err;
+
+ if (ext4_handle_has_enough_credits(handle, thresh))
+ return 0;
+
+ err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
+ if (err < 0)
+ return err;
+ if (err) {
+ err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/*
+ * 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;
+
+ group = ext4_get_group_number(sb, block);
+ start = ext4_group_first_block_no(sb, group);
+ group -= flex_gd->groups[0].group;
+
+ count2 = EXT4_BLOCKS_PER_GROUP(sb) - (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 (unlikely(!bh))
+ return -ENOMEM;
+
+ BUFFER_TRACE(bh, "get_write_access");
+ 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_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);
+ 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_group_t group, count;
+ struct buffer_head *bh = NULL;
+ int reserved_gdb, i, j, err = 0, err2;
+ int meta_bg;
+
+ 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);
+ meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
+
+ /* This transaction may be extended/restarted along the way */
+ handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ group = group_data[0].group;
+ for (i = 0; i < flex_gd->count; i++, group++) {
+ unsigned long gdblocks;
+ ext4_grpblk_t overhead;
+
+ gdblocks = ext4_bg_num_gdb(sb, group);
+ start = ext4_group_first_block_no(sb, group);
+
+ if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
+ goto handle_itb;
+
+ if (meta_bg == 1) {
+ ext4_group_t first_group;
+ first_group = ext4_meta_bg_first_group(sb, group);
+ if (first_group != group + 1 &&
+ first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1)
+ goto handle_itb;
+ }
+
+ block = start + ext4_bg_has_super(sb, group);
+ /* Copy all of the GDT blocks into the backup in this group */
+ for (j = 0; j < gdblocks; j++, block++) {
+ struct buffer_head *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 (unlikely(!gdb)) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ BUFFER_TRACE(gdb, "get_write_access");
+ 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);
+ }
+
+ /* 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;
+ }
+
+handle_itb:
+ /* Initialize group tables of the grop @group */
+ if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
+ goto handle_bb;
+
+ /* 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;
+
+handle_bb:
+ if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
+ goto handle_ib;
+
+ /* Initialize block bitmap of the @group */
+ block = group_data[i].block_bitmap;
+ err = extend_or_restart_transaction(handle, 1);
+ if (err)
+ goto out;
+
+ bh = bclean(handle, sb, block);
+ if (IS_ERR(bh)) {
+ err = PTR_ERR(bh);
+ bh = NULL;
+ goto out;
+ }
+ overhead = ext4_group_overhead_blocks(sb, group);
+ if (overhead != 0) {
+ ext4_debug("mark backup superblock %#04llx (+0)\n",
+ start);
+ ext4_set_bits(bh->b_data, 0, overhead);
+ }
+ 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;
+
+ /* 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);
+ bh = NULL;
+ 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);
+ }
+ 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)[j];
+ block = start;
+ }
+
+ if (count) {
+ err = set_flexbg_block_bitmap(sb, handle,
+ flex_gd, start, count);
+ if (err)
+ goto out;
+ }
+ }
+
+out:
+ brelse(bh);
+ err2 = ext4_journal_stop(handle);
+ if (err2 && !err)
+ err = err2;
+
+ return err;
+}
+
+/*
+ * Iterate through the groups which hold BACKUP superblock/GDT copies in an
+ * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
+ * calling this for the first time. In a sparse filesystem it will be the
+ * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
+ * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
+ */
+static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
+ unsigned *five, unsigned *seven)
+{
+ unsigned *min = three;
+ int mult = 3;
+ unsigned ret;
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
+ ret = *min;
+ *min += 1;
+ return ret;
+ }
+
+ if (*five < *min) {
+ min = five;
+ mult = 5;
+ }
+ if (*seven < *min) {
+ min = seven;
+ mult = 7;
+ }
+
+ ret = *min;
+ *min *= mult;
+
+ return ret;
+}
+
+/*
+ * Check that all of the backup GDT blocks are held in the primary GDT block.
+ * It is assumed that they are stored in group order. Returns the number of
+ * groups in current filesystem that have BACKUPS, or -ve error code.
+ */
+static int verify_reserved_gdb(struct super_block *sb,
+ ext4_group_t end,
+ struct buffer_head *primary)
+{
+ const ext4_fsblk_t blk = primary->b_blocknr;
+ unsigned three = 1;
+ unsigned five = 5;
+ unsigned seven = 7;
+ unsigned grp;
+ __le32 *p = (__le32 *)primary->b_data;
+ int gdbackups = 0;
+
+ while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
+ if (le32_to_cpu(*p++) !=
+ grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
+ ext4_warning(sb, "reserved GDT %llu"
+ " missing grp %d (%llu)",
+ blk, grp,
+ grp *
+ (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
+ blk);
+ return -EINVAL;
+ }
+ if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
+ return -EFBIG;
+ }
+
+ return gdbackups;
+}
+
+/*
+ * Called when we need to bring a reserved group descriptor table block into
+ * use from the resize inode. The primary copy of the new GDT block currently
+ * is an indirect block (under the double indirect block in the resize inode).
+ * The new backup GDT blocks will be stored as leaf blocks in this indirect
+ * block, in group order. Even though we know all the block numbers we need,
+ * we check to ensure that the resize inode has actually reserved these blocks.
+ *
+ * Don't need to update the block bitmaps because the blocks are still in use.
+ *
+ * We get all of the error cases out of the way, so that we are sure to not
+ * fail once we start modifying the data on disk, because JBD has no rollback.
+ */
+static int add_new_gdb(handle_t *handle, struct inode *inode,
+ ext4_group_t group)
+{
+ struct super_block *sb = inode->i_sb;
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+ unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+ ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
+ struct buffer_head **o_group_desc, **n_group_desc;
+ struct buffer_head *dind;
+ struct buffer_head *gdb_bh;
+ int gdbackups;
+ struct ext4_iloc iloc;
+ __le32 *data;
+ int err;
+
+ if (test_opt(sb, DEBUG))
+ printk(KERN_DEBUG
+ "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
+ gdb_num);
+
+ gdb_bh = sb_bread(sb, gdblock);
+ if (!gdb_bh)
+ return -EIO;
+
+ gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
+ if (gdbackups < 0) {
+ err = gdbackups;
+ goto exit_bh;
+ }
+
+ data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
+ dind = sb_bread(sb, le32_to_cpu(*data));
+ if (!dind) {
+ err = -EIO;
+ goto exit_bh;
+ }
+
+ data = (__le32 *)dind->b_data;
+ if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
+ ext4_warning(sb, "new group %u GDT block %llu not reserved",
+ group, gdblock);
+ err = -EINVAL;
+ goto exit_dind;
+ }
+
+ BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+ if (unlikely(err))
+ goto exit_dind;
+
+ BUFFER_TRACE(gdb_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, gdb_bh);
+ if (unlikely(err))
+ goto exit_dind;
+
+ BUFFER_TRACE(dind, "get_write_access");
+ err = ext4_journal_get_write_access(handle, dind);
+ if (unlikely(err))
+ ext4_std_error(sb, err);
+
+ /* ext4_reserve_inode_write() gets a reference on the iloc */
+ err = ext4_reserve_inode_write(handle, inode, &iloc);
+ if (unlikely(err))
+ goto exit_dind;
+
+ n_group_desc = ext4_kvmalloc((gdb_num + 1) *
+ sizeof(struct buffer_head *),
+ GFP_NOFS);
+ if (!n_group_desc) {
+ err = -ENOMEM;
+ ext4_warning(sb, "not enough memory for %lu groups",
+ gdb_num + 1);
+ goto exit_inode;
+ }
+
+ /*
+ * Finally, we have all of the possible failures behind us...
+ *
+ * Remove new GDT block from inode double-indirect block and clear out
+ * the new GDT block for use (which also "frees" the backup GDT blocks
+ * from the reserved inode). We don't need to change the bitmaps for
+ * these blocks, because they are marked as in-use from being in the
+ * reserved inode, and will become GDT blocks (primary and backup).
+ */
+ data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
+ err = ext4_handle_dirty_metadata(handle, NULL, dind);
+ if (unlikely(err)) {
+ ext4_std_error(sb, err);
+ goto exit_inode;
+ }
+ inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
+ ext4_mark_iloc_dirty(handle, inode, &iloc);
+ memset(gdb_bh->b_data, 0, sb->s_blocksize);
+ err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
+ if (unlikely(err)) {
+ ext4_std_error(sb, err);
+ goto exit_inode;
+ }
+ brelse(dind);
+
+ o_group_desc = EXT4_SB(sb)->s_group_desc;
+ memcpy(n_group_desc, o_group_desc,
+ EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+ n_group_desc[gdb_num] = gdb_bh;
+ EXT4_SB(sb)->s_group_desc = n_group_desc;
+ EXT4_SB(sb)->s_gdb_count++;
+ kvfree(o_group_desc);
+
+ le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
+ err = ext4_handle_dirty_super(handle, sb);
+ if (err)
+ ext4_std_error(sb, err);
+
+ return err;
+
+exit_inode:
+ kvfree(n_group_desc);
+ brelse(iloc.bh);
+exit_dind:
+ brelse(dind);
+exit_bh:
+ brelse(gdb_bh);
+
+ ext4_debug("leaving with error %d\n", err);
+ return err;
+}
+
+/*
+ * add_new_gdb_meta_bg is the sister of add_new_gdb.
+ */
+static int add_new_gdb_meta_bg(struct super_block *sb,
+ handle_t *handle, ext4_group_t group) {
+ ext4_fsblk_t gdblock;
+ struct buffer_head *gdb_bh;
+ struct buffer_head **o_group_desc, **n_group_desc;
+ unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+ int err;
+
+ gdblock = ext4_meta_bg_first_block_no(sb, group) +
+ ext4_bg_has_super(sb, group);
+ gdb_bh = sb_bread(sb, gdblock);
+ if (!gdb_bh)
+ return -EIO;
+ n_group_desc = ext4_kvmalloc((gdb_num + 1) *
+ sizeof(struct buffer_head *),
+ GFP_NOFS);
+ if (!n_group_desc) {
+ err = -ENOMEM;
+ ext4_warning(sb, "not enough memory for %lu groups",
+ gdb_num + 1);
+ return err;
+ }
+
+ o_group_desc = EXT4_SB(sb)->s_group_desc;
+ memcpy(n_group_desc, o_group_desc,
+ EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+ n_group_desc[gdb_num] = gdb_bh;
+ EXT4_SB(sb)->s_group_desc = n_group_desc;
+ EXT4_SB(sb)->s_gdb_count++;
+ kvfree(o_group_desc);
+ BUFFER_TRACE(gdb_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, gdb_bh);
+ if (unlikely(err))
+ brelse(gdb_bh);
+ 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,
+ ext4_group_t group)
+{
+ struct super_block *sb = inode->i_sb;
+ int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
+ struct buffer_head **primary;
+ struct buffer_head *dind;
+ struct ext4_iloc iloc;
+ ext4_fsblk_t blk;
+ __le32 *data, *end;
+ int gdbackups = 0;
+ int res, i;
+ int err;
+
+ primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
+ if (!primary)
+ return -ENOMEM;
+
+ data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
+ dind = sb_bread(sb, le32_to_cpu(*data));
+ if (!dind) {
+ err = -EIO;
+ goto exit_free;
+ }
+
+ blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
+ data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
+ EXT4_ADDR_PER_BLOCK(sb));
+ end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
+
+ /* Get each reserved primary GDT block and verify it holds backups */
+ for (res = 0; res < reserved_gdb; res++, blk++) {
+ if (le32_to_cpu(*data) != blk) {
+ ext4_warning(sb, "reserved block %llu"
+ " not at offset %ld",
+ blk,
+ (long)(data - (__le32 *)dind->b_data));
+ err = -EINVAL;
+ goto exit_bh;
+ }
+ primary[res] = sb_bread(sb, blk);
+ if (!primary[res]) {
+ err = -EIO;
+ goto exit_bh;
+ }
+ gdbackups = verify_reserved_gdb(sb, group, primary[res]);
+ if (gdbackups < 0) {
+ brelse(primary[res]);
+ err = gdbackups;
+ goto exit_bh;
+ }
+ if (++data >= end)
+ data = (__le32 *)dind->b_data;
+ }
+
+ for (i = 0; i < reserved_gdb; i++) {
+ BUFFER_TRACE(primary[i], "get_write_access");
+ if ((err = ext4_journal_get_write_access(handle, primary[i])))
+ goto exit_bh;
+ }
+
+ if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
+ goto exit_bh;
+
+ /*
+ * Finally we can add each of the reserved backup GDT blocks from
+ * the new group to its reserved primary GDT block.
+ */
+ blk = group * EXT4_BLOCKS_PER_GROUP(sb);
+ for (i = 0; i < reserved_gdb; i++) {
+ int err2;
+ data = (__le32 *)primary[i]->b_data;
+ /* printk("reserving backup %lu[%u] = %lu\n",
+ primary[i]->b_blocknr, gdbackups,
+ blk + primary[i]->b_blocknr); */
+ data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
+ err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
+ if (!err)
+ err = err2;
+ }
+ inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
+ ext4_mark_iloc_dirty(handle, inode, &iloc);
+
+exit_bh:
+ while (--res >= 0)
+ brelse(primary[res]);
+ brelse(dind);
+
+exit_free:
+ kfree(primary);
+
+ return err;
+}
+
+/*
+ * Update the backup copies of the ext4 metadata. These don't need to be part
+ * of the main resize transaction, because e2fsck will re-write them if there
+ * is a problem (basically only OOM will cause a problem). However, we
+ * _should_ update the backups if possible, in case the primary gets trashed
+ * for some reason and we need to run e2fsck from a backup superblock. The
+ * important part is that the new block and inode counts are in the backup
+ * superblocks, and the location of the new group metadata in the GDT backups.
+ *
+ * We do not need take the s_resize_lock for this, because these
+ * blocks are not otherwise touched by the filesystem code when it is
+ * mounted. We don't need to worry about last changing from
+ * sbi->s_groups_count, because the worst that can happen is that we
+ * do not copy the full number of backups at this time. The resize
+ * which changed s_groups_count will backup again.
+ */
+static void update_backups(struct super_block *sb, int blk_off, char *data,
+ int size, int meta_bg)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_group_t last;
+ const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
+ unsigned three = 1;
+ unsigned five = 5;
+ unsigned seven = 7;
+ ext4_group_t group = 0;
+ int rest = sb->s_blocksize - size;
+ handle_t *handle;
+ int err = 0, err2;
+
+ handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
+ if (IS_ERR(handle)) {
+ group = 1;
+ err = PTR_ERR(handle);
+ goto exit_err;
+ }
+
+ if (meta_bg == 0) {
+ group = ext4_list_backups(sb, &three, &five, &seven);
+ last = sbi->s_groups_count;
+ } else {
+ group = ext4_meta_bg_first_group(sb, group) + 1;
+ last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
+ }
+
+ while (group < sbi->s_groups_count) {
+ struct buffer_head *bh;
+ ext4_fsblk_t backup_block;
+
+ /* Out of journal space, and can't get more - abort - so sad */
+ if (ext4_handle_valid(handle) &&
+ handle->h_buffer_credits == 0 &&
+ ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
+ (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
+ break;
+
+ if (meta_bg == 0)
+ backup_block = ((ext4_fsblk_t)group) * bpg + blk_off;
+ else
+ backup_block = (ext4_group_first_block_no(sb, group) +
+ ext4_bg_has_super(sb, group));
+
+ bh = sb_getblk(sb, backup_block);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ break;
+ }
+ ext4_debug("update metadata backup %llu(+%llu)\n",
+ backup_block, backup_block -
+ ext4_group_first_block_no(sb, group));
+ BUFFER_TRACE(bh, "get_write_access");
+ if ((err = ext4_journal_get_write_access(handle, bh)))
+ break;
+ lock_buffer(bh);
+ memcpy(bh->b_data, data, size);
+ if (rest)
+ memset(bh->b_data + size, 0, rest);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ err = ext4_handle_dirty_metadata(handle, NULL, bh);
+ if (unlikely(err))
+ ext4_std_error(sb, err);
+ brelse(bh);
+
+ if (meta_bg == 0)
+ group = ext4_list_backups(sb, &three, &five, &seven);
+ else if (group == last)
+ break;
+ else
+ group = last;
+ }
+ if ((err2 = ext4_journal_stop(handle)) && !err)
+ err = err2;
+
+ /*
+ * Ugh! Need to have e2fsck write the backup copies. It is too
+ * late to revert the resize, we shouldn't fail just because of
+ * the backup copies (they are only needed in case of corruption).
+ *
+ * However, if we got here we have a journal problem too, so we
+ * can't really start a transaction to mark the superblock.
+ * Chicken out and just set the flag on the hope it will be written
+ * to disk, and if not - we will simply wait until next fsck.
+ */
+exit_err:
+ if (err) {
+ ext4_warning(sb, "can't update backup for group %u (err %d), "
+ "forcing fsck on next reboot", group, err);
+ sbi->s_mount_state &= ~EXT4_VALID_FS;
+ sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
+ mark_buffer_dirty(sbi->s_sbh);
+ }
+}
+
+/*
+ * 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;
+ int meta_bg;
+
+ meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
+ 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];
+ BUFFER_TRACE(gdb_bh, "get_write_access");
+ 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 if (meta_bg != 0) {
+ err = add_new_gdb_meta_bg(sb, handle, group);
+ } else {
+ err = add_new_gdb(handle, resize_inode, group);
+ }
+ if (err)
+ break;
+ }
+ return err;
+}
+
+static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
+{
+ struct buffer_head *bh = sb_getblk(sb, block);
+ if (unlikely(!bh))
+ return NULL;
+ if (!bh_uptodate_or_lock(bh)) {
+ if (bh_submit_read(bh) < 0) {
+ brelse(bh);
+ return NULL;
+ }
+ }
+
+ return bh;
+}
+
+static int ext4_set_bitmap_checksums(struct super_block *sb,
+ ext4_group_t group,
+ struct ext4_group_desc *gdp,
+ struct ext4_new_group_data *group_data)
+{
+ struct buffer_head *bh;
+
+ if (!ext4_has_metadata_csum(sb))
+ return 0;
+
+ bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
+ if (!bh)
+ return -EIO;
+ ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
+ EXT4_INODES_PER_GROUP(sb) / 8);
+ brelse(bh);
+
+ bh = ext4_get_bitmap(sb, group_data->block_bitmap);
+ if (!bh)
+ return -EIO;
+ ext4_block_bitmap_csum_set(sb, group, gdp, bh);
+ brelse(bh);
+
+ return 0;
+}
+
+/*
+ * 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 *)(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);
+ err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
+ if (err) {
+ ext4_std_error(sb, err);
+ break;
+ }
+
+ ext4_inode_table_set(sb, gdp, group_data->inode_table);
+ ext4_free_group_clusters_set(sb, gdp,
+ EXT4_NUM_B2C(sbi, group_data->free_blocks_count));
+ ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
+ if (ext4_has_group_desc_csum(sb))
+ ext4_itable_unused_set(sb, gdp,
+ EXT4_INODES_PER_GROUP(sb));
+ gdp->bg_flags = cpu_to_le16(*bg_flags);
+ ext4_group_desc_csum_set(sb, 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;
+ reserved_blocks = div64_u64(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);
+ ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
+ le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
+ flex_gd->count);
+ le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
+ flex_gd->count);
+
+ ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
+ /*
+ * 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;
+ sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
+ (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
+
+ /* 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_NUM_B2C(sbi, free_blocks));
+ percpu_counter_add(&sbi->s_freeinodes_counter,
+ EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
+
+ ext4_debug("free blocks count %llu",
+ percpu_counter_read(&sbi->s_freeclusters_counter));
+ 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);
+ atomic64_add(EXT4_NUM_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);
+ }
+
+ /*
+ * Update the fs overhead information
+ */
+ ext4_calculate_overhead(sb);
+
+ 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
+ * blocks. 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 = 3; /* sb, resize inode, resize inode dindirect */
+ /* GDT blocks */
+ credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb));
+ credit += reserved_gdb; /* Reserved GDT dindirect blocks */
+ handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto exit;
+ }
+
+ BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+ 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 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+ int gdb_num_end = ((group + flex_gd->count - 1) /
+ EXT4_DESC_PER_BLOCK(sb));
+ int meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb,
+ EXT4_FEATURE_INCOMPAT_META_BG);
+ sector_t old_gdb = 0;
+
+ update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
+ sizeof(struct ext4_super_block), 0);
+ for (; gdb_num <= gdb_num_end; gdb_num++) {
+ struct buffer_head *gdb_bh;
+
+ gdb_bh = sbi->s_group_desc[gdb_num];
+ if (old_gdb == gdb_bh->b_blocknr)
+ continue;
+ update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
+ gdb_bh->b_size, meta_bg);
+ old_gdb = gdb_bh->b_blocknr;
+ }
+ }
+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_group_overhead_blocks(sb, group + i);
+ group_data[i].free_blocks_count = blocks_per_group - overhead;
+ if (ext4_has_group_desc_csum(sb)) {
+ flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
+ EXT4_BG_INODE_UNINIT;
+ if (!test_opt(sb, INIT_INODE_TABLE))
+ flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED;
+ } else
+ flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
+ }
+
+ if (last_group == n_group && ext4_has_group_desc_csum(sb))
+ /* 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
+ * write the data to disk.
+ *
+ * If we are on a GDT block boundary, we need to get the reserved GDT block.
+ * Otherwise, we may need to add backup GDT blocks for a sparse group.
+ *
+ * We only need to hold the superblock lock while we are actually adding
+ * in the new group's counts to the superblock. Prior to that we have
+ * not really "added" the group at all. We re-check that we are still
+ * adding in the last group in case things have changed since verifying.
+ */
+int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
+{
+ struct ext4_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 inode *inode = NULL;
+ int gdb_off;
+ int err;
+ __u16 bg_flags = 0;
+
+ gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
+
+ if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
+ ext4_warning(sb, "Can't resize non-sparse filesystem further");
+ return -EPERM;
+ }
+
+ if (ext4_blocks_count(es) + input->blocks_count <
+ ext4_blocks_count(es)) {
+ ext4_warning(sb, "blocks_count overflow");
+ return -EINVAL;
+ }
+
+ if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
+ le32_to_cpu(es->s_inodes_count)) {
+ ext4_warning(sb, "inodes_count overflow");
+ return -EINVAL;
+ }
+
+ if (reserved_gdb || gdb_off == 0) {
+ if (!EXT4_HAS_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_COMPAT_RESIZE_INODE)
+ || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
+ ext4_warning(sb,
+ "No reserved GDT blocks, can't resize");
+ return -EPERM;
+ }
+ inode = ext4_iget(sb, EXT4_RESIZE_INO);
+ if (IS_ERR(inode)) {
+ ext4_warning(sb, "Error opening resize inode");
+ return PTR_ERR(inode);
+ }
+ }
+
+
+ err = verify_group_input(sb, input);
+ if (err)
+ goto out;
+
+ err = ext4_alloc_flex_bg_array(sb, input->group + 1);
+ if (err)
+ goto out;
+
+ err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
+ if (err)
+ goto out;
+
+ 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 */
+
+/*
+ * 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_HT_RESIZE, 3);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ ext4_warning(sb, "error %d on journal start", err);
+ return err;
+ }
+
+ BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
+ 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;
+ }
+
+ ext4_blocks_count_set(es, o_blocks_count + add);
+ ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + 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 errout;
+ ext4_handle_dirty_super(handle, sb);
+ 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) {
+ 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), 0);
+ }
+ return err;
+}
+
+/*
+ * Extend the filesystem to the new number of blocks specified. This entry
+ * point is only used to extend the current filesystem to the end of the last
+ * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
+ * for emergencies (because it has no dependencies on reserved blocks).
+ *
+ * If we _really_ wanted, we could use default values to call ext4_group_add()
+ * allow the "remount" trick to work for arbitrary resizing, assuming enough
+ * GDT blocks are reserved to grow to the desired size.
+ */
+int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
+ ext4_fsblk_t n_blocks_count)
+{
+ ext4_fsblk_t o_blocks_count;
+ ext4_grpblk_t last;
+ ext4_grpblk_t add;
+ struct buffer_head *bh;
+ int err;
+ ext4_group_t group;
+
+ o_blocks_count = ext4_blocks_count(es);
+
+ if (test_opt(sb, DEBUG))
+ ext4_msg(sb, KERN_DEBUG,
+ "extending last group from %llu to %llu blocks",
+ 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)) {
+ ext4_msg(sb, KERN_ERR,
+ "filesystem too large to resize to %llu blocks safely",
+ n_blocks_count);
+ if (sizeof(sector_t) < 8)
+ ext4_warning(sb, "CONFIG_LBDAF not enabled");
+ return -EINVAL;
+ }
+
+ if (n_blocks_count < o_blocks_count) {
+ ext4_warning(sb, "can't shrink FS - resize aborted");
+ return -EINVAL;
+ }
+
+ /* Handle the remaining blocks in the last group only. */
+ ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
+
+ if (last == 0) {
+ ext4_warning(sb, "need to use ext2online to resize further");
+ return -EPERM;
+ }
+
+ add = EXT4_BLOCKS_PER_GROUP(sb) - last;
+
+ if (o_blocks_count + add < o_blocks_count) {
+ ext4_warning(sb, "blocks_count overflow");
+ return -EINVAL;
+ }
+
+ if (o_blocks_count + add > n_blocks_count)
+ add = n_blocks_count - o_blocks_count;
+
+ if (o_blocks_count + add < n_blocks_count)
+ ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
+ o_blocks_count + add, add);
+
+ /* See if the device is actually as big as what was requested */
+ bh = sb_bread(sb, o_blocks_count + add - 1);
+ if (!bh) {
+ ext4_warning(sb, "can't read last block, resize aborted");
+ return -ENOSPC;
+ }
+ brelse(bh);
+
+ err = ext4_group_extend_no_check(sb, o_blocks_count, add);
+ return err;
+} /* ext4_group_extend */
+
+
+static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
+{
+ return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
+}
+
+/*
+ * Release the resize inode and drop the resize_inode feature if there
+ * are no more reserved gdt blocks, and then convert the file system
+ * to enable meta_bg
+ */
+static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
+{
+ handle_t *handle;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ ext4_fsblk_t nr;
+ int i, ret, err = 0;
+ int credits = 1;
+
+ ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
+ if (inode) {
+ if (es->s_reserved_gdt_blocks) {
+ ext4_error(sb, "Unexpected non-zero "
+ "s_reserved_gdt_blocks");
+ return -EPERM;
+ }
+
+ /* Do a quick sanity check of the resize inode */
+ if (inode->i_blocks != 1 << (inode->i_blkbits - 9))
+ goto invalid_resize_inode;
+ for (i = 0; i < EXT4_N_BLOCKS; i++) {
+ if (i == EXT4_DIND_BLOCK) {
+ if (ei->i_data[i])
+ continue;
+ else
+ goto invalid_resize_inode;
+ }
+ if (ei->i_data[i])
+ goto invalid_resize_inode;
+ }
+ credits += 3; /* block bitmap, bg descriptor, resize inode */
+ }
+
+ handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+ if (err)
+ goto errout;
+
+ EXT4_CLEAR_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE);
+ EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
+ sbi->s_es->s_first_meta_bg =
+ cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
+
+ err = ext4_handle_dirty_super(handle, sb);
+ if (err) {
+ ext4_std_error(sb, err);
+ goto errout;
+ }
+
+ if (inode) {
+ nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
+ ext4_free_blocks(handle, inode, NULL, nr, 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
+ ei->i_data[EXT4_DIND_BLOCK] = 0;
+ inode->i_blocks = 0;
+
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (err)
+ ext4_std_error(sb, err);
+ }
+
+errout:
+ ret = ext4_journal_stop(handle);
+ if (!err)
+ err = ret;
+ return ret;
+
+invalid_resize_inode:
+ ext4_error(sb, "corrupted/inconsistent resize inode");
+ return -EINVAL;
+}
+
+/*
+ * 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 = NULL;
+ ext4_grpblk_t add, offset;
+ unsigned long n_desc_blocks;
+ unsigned long o_desc_blocks;
+ ext4_group_t o_group;
+ ext4_group_t n_group;
+ ext4_fsblk_t o_blocks_count;
+ ext4_fsblk_t n_blocks_count_retry = 0;
+ unsigned long last_update_time = 0;
+ int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
+ int meta_bg;
+
+ /* 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);
+
+retry:
+ o_blocks_count = ext4_blocks_count(es);
+
+ ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
+ "to %llu blocks", 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 (n_blocks_count == o_blocks_count)
+ /* Nothing need to do */
+ return 0;
+
+ n_group = ext4_get_group_number(sb, n_blocks_count - 1);
+ if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
+ ext4_warning(sb, "resize would cause inodes_count overflow");
+ return -EINVAL;
+ }
+ ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
+
+ n_desc_blocks = num_desc_blocks(sb, n_group + 1);
+ o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
+
+ meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
+
+ if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE)) {
+ if (meta_bg) {
+ ext4_error(sb, "resize_inode and meta_bg enabled "
+ "simultaneously");
+ return -EINVAL;
+ }
+ if (n_desc_blocks > o_desc_blocks +
+ le16_to_cpu(es->s_reserved_gdt_blocks)) {
+ n_blocks_count_retry = n_blocks_count;
+ n_desc_blocks = o_desc_blocks +
+ le16_to_cpu(es->s_reserved_gdt_blocks);
+ n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
+ n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb);
+ n_group--; /* set to last group number */
+ }
+
+ if (!resize_inode)
+ 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);
+ }
+ }
+
+ if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
+ err = ext4_convert_meta_bg(sb, resize_inode);
+ if (err)
+ goto out;
+ if (resize_inode) {
+ iput(resize_inode);
+ resize_inode = NULL;
+ }
+ if (n_blocks_count_retry) {
+ n_blocks_count = n_blocks_count_retry;
+ n_blocks_count_retry = 0;
+ goto retry;
+ }
+ }
+
+ /* extend the last group */
+ if (n_group == o_group)
+ add = n_blocks_count - o_blocks_count;
+ else
+ add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1);
+ if (add > 0) {
+ err = ext4_group_extend_no_check(sb, o_blocks_count, add);
+ if (err)
+ goto out;
+ }
+
+ if (ext4_blocks_count(es) == n_blocks_count)
+ goto out;
+
+ err = ext4_alloc_flex_bg_array(sb, n_group + 1);
+ if (err)
+ return err;
+
+ err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
+ if (err)
+ 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)) {
+ if (jiffies - last_update_time > HZ * 10) {
+ if (last_update_time)
+ ext4_msg(sb, KERN_INFO,
+ "resized to %llu blocks",
+ ext4_blocks_count(es));
+ last_update_time = jiffies;
+ }
+ if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
+ break;
+ err = ext4_flex_group_add(sb, resize_inode, flex_gd);
+ if (unlikely(err))
+ break;
+ }
+
+ if (!err && n_blocks_count_retry) {
+ n_blocks_count = n_blocks_count_retry;
+ n_blocks_count_retry = 0;
+ free_flex_gd(flex_gd);
+ flex_gd = NULL;
+ goto retry;
+ }
+
+out:
+ if (flex_gd)
+ free_flex_gd(flex_gd);
+ if (resize_inode != NULL)
+ iput(resize_inode);
+ ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);
+ return err;
+}
Code Review / kvmfornfv.git / blobdiff