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ext4: let ext4_group_add() use common code
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This patch lets ext4_group_add() call ext4_flex_group_add().

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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Yongqiang Yang authored and Theodore Ts'o committed Jan 4, 2012
1 parent d89651c commit 61f296c
Showing 1 changed file with 10 additions and 299 deletions.
309 changes: 10 additions & 299 deletions fs/ext4/resize.c
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Original file line number Diff line number Diff line change
@@ -594,137 +594,6 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
return err;
}

/*
* Set up the block and inode bitmaps, and the inode table for the new group.
* This doesn't need to be part of the main transaction, since we are only
* changing blocks outside the actual filesystem. We still do journaling to
* ensure the recovery is correct in case of a failure just after resize.
* If any part of this fails, we simply abort the resize.
*/
static int setup_new_group_blocks(struct super_block *sb,
struct ext4_new_group_data *input)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
struct buffer_head *bh;
handle_t *handle;
ext4_fsblk_t block;
ext4_grpblk_t bit;
int i;
int err = 0, err2;

/* This transaction may be extended/restarted along the way */
handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);

if (IS_ERR(handle))
return PTR_ERR(handle);

BUG_ON(input->group != sbi->s_groups_count);

/* Copy all of the GDT blocks into the backup in this group */
for (i = 0, bit = 1, block = start + 1;
i < gdblocks; i++, block++, bit++) {
struct buffer_head *gdb;

ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
err = extend_or_restart_transaction(handle, 1);
if (err)
goto exit_journal;

gdb = sb_getblk(sb, block);
if (!gdb) {
err = -EIO;
goto exit_journal;
}
if ((err = ext4_journal_get_write_access(handle, gdb))) {
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;
}
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;

err = extend_or_restart_transaction(handle, 2);
if (err)
goto exit_journal;

bh = bclean(handle, sb, input->block_bitmap);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
goto exit_journal;
}

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);
}

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);


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;
}
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;
}

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:
brelse(bh);

exit_journal:
if ((err2 = ext4_journal_stop(handle)) && !err)
err = err2;

return err;
}

/*
* Iterate through the groups which hold BACKUP superblock/GDT copies in an
* ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
@@ -1509,16 +1378,15 @@ static int ext4_setup_next_flex_gd(struct super_block *sb,
*/
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);
@@ -1557,172 +1425,15 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
}


if ((err = verify_group_input(sb, input)))
goto exit_put;

if ((err = setup_new_group_blocks(sb, input)))
goto exit_put;

/*
* We will always be modifying at least the superblock and a GDT
* block. If we are adding a group past the last current GDT block,
* we will also modify the inode and the dindirect block. If we
* are adding a group with superblock/GDT backups we will also
* modify each of the reserved GDT dindirect blocks.
*/
handle = ext4_journal_start_sb(sb,
ext4_bg_has_super(sb, input->group) ?
3 + reserved_gdb : 4);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto exit_put;
}

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];
}

/*
* 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);
err = verify_group_input(sb, input);
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);
}

ext4_handle_dirty_super(handle, sb);
goto out;

exit_journal:
if ((err2 = ext4_journal_stop(handle)) && !err)
err = err2;
if (!err && primary) {
update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
sizeof(struct ext4_super_block));
update_backups(sb, primary->b_blocknr, primary->b_data,
primary->b_size);
}
exit_put:
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 */

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