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Message-Id: <1325242437-26934-7-git-send-email-xiaoqiangnk@gmail.com>
Date: Fri, 30 Dec 2011 18:53:48 +0800
From: Yongqiang Yang <xiaoqiangnk@...il.com>
To: tytso@....edu
Cc: linux-ext4@...r.kernel.org, Yongqiang Yang <xiaoqiangnk@...il.com>
Subject: [PATCH V6 06/15] ext4: add a function which sets up group blocks of a flex groups
From: Yongqiang Yang <xiaoqiangnk@...il.com>
This patch adds a function named setup_new_flex_group_blocks() which
sets up group blocks of a flex groups.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@...il.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
fs/ext4/ext4.h | 8 ++
fs/ext4/resize.c | 250 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 258 insertions(+), 0 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0e43bba..05058e2 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -511,6 +511,14 @@ struct ext4_new_group_data {
__u32 free_blocks_count;
};
+/* Indexes used to index group tables in ext4_new_group_data */
+enum {
+ BLOCK_BITMAP = 0, /* block bitmap */
+ INODE_BITMAP, /* inode bitmap */
+ INODE_TABLE, /* inode tables */
+ GROUP_TABLE_COUNT,
+};
+
/*
* Flags used by ext4_map_blocks()
*/
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 78f3bab..3024769 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -234,6 +234,256 @@ static int extend_or_restart_transaction(handle_t *handle, int thresh)
}
/*
+ * 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_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;
+
+ 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);
+
+ group = group_data[0].group;
+ for (i = 0; i < flex_gd->count; i++, group++) {
+ unsigned long gdblocks;
+
+ gdblocks = ext4_bg_num_gdb(sb, group);
+ start = ext4_group_first_block_no(sb, group);
+
+ /* 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;
+
+ 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);
+ }
+
+ /* 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;
+ }
+
+ /* 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);
+ 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;
+
+ /* 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);
+ }
+ 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;
+ }
+ }
+
+out:
+ brelse(bh);
+ err2 = ext4_journal_stop(handle);
+ if (err2 && !err)
+ err = err2;
+
+ 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
--
1.7.5.1
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