Whamcloud - gitweb
Branch b1_6
authorjohann <johann>
Tue, 17 Jul 2007 07:01:11 +0000 (07:01 +0000)
committerjohann <johann>
Tue, 17 Jul 2007 07:01:11 +0000 (07:01 +0000)
b=11039
i=adilger
i=kalpak

attachment 11410 / uninit support for 2.6.18

ldiskfs/kernel_patches/patches/ext3-uninit-2.6.18.patch [new file with mode: 0644]

diff --git a/ldiskfs/kernel_patches/patches/ext3-uninit-2.6.18.patch b/ldiskfs/kernel_patches/patches/ext3-uninit-2.6.18.patch
new file mode 100644 (file)
index 0000000..d79674b
--- /dev/null
@@ -0,0 +1,664 @@
+Add support for the uninit_groups feature to the kernel.
+
+Keep a high water mark of used inodes for each group to improve e2fsck time.
+Block and inode bitmaps can be uninitialized on disk via a flag in the
+group descriptor to avoid reading or scanning them at e2fsck time.
+A checksum of each group descriptor is used to ensure that corruption in
+the group descriptor's bit flags does not cause incorrect operation.
+
+Index: linux-2.6.18.8.orig/include/linux/ext3_fs.h
+===================================================================
+--- linux-2.6.18.8.orig.orig/include/linux/ext3_fs.h   2007-07-02 11:09:25.000000000 +0200
++++ linux-2.6.18.8.orig/include/linux/ext3_fs.h        2007-07-02 11:09:31.000000000 +0200
+@@ -150,16 +150,22 @@ struct ext3_allocation_request {
+  */
+ struct ext3_group_desc
+ {
+-      __le32  bg_block_bitmap;                /* Blocks bitmap block */
+-      __le32  bg_inode_bitmap;                /* Inodes bitmap block */
++      __le32  bg_block_bitmap;        /* Blocks bitmap block */
++      __le32  bg_inode_bitmap;        /* Inodes bitmap block */
+       __le32  bg_inode_table;         /* Inodes table block */
+       __le16  bg_free_blocks_count;   /* Free blocks count */
+       __le16  bg_free_inodes_count;   /* Free inodes count */
+       __le16  bg_used_dirs_count;     /* Directories count */
+-      __u16   bg_pad;
+-      __le32  bg_reserved[3];
++      __le16  bg_flags;               /* EXT3_BG_flags (UNINIT, etc) */
++      __le32  bg_reserved[2];         /* Likely block/inode bitmap checksum */
++      __le16  bg_itable_unused;       /* Unused inodes count */
++      __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
+ };
++#define EXT3_BG_INODE_UNINIT  0x0001 /* Inode table/bitmap not in use */
++#define EXT3_BG_BLOCK_UNINIT  0x0002 /* Block bitmap not in use */
++#define EXT3_BG_INODE_ZEROED  0x0004 /* On-disk itable initialized to zero */
++
+ /*
+  * Macro-instructions used to manage group descriptors
+  */
+@@ -603,6 +609,7 @@ static inline int ext3_valid_inum(struct
+ #define EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER   0x0001
+ #define EXT3_FEATURE_RO_COMPAT_LARGE_FILE     0x0002
+ #define EXT3_FEATURE_RO_COMPAT_BTREE_DIR      0x0004
++#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM               0x0010
+ #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK      0x0020
+ #define EXT3_FEATURE_INCOMPAT_COMPRESSION     0x0001
+@@ -619,6 +626,7 @@ static inline int ext3_valid_inum(struct
+                                        EXT3_FEATURE_INCOMPAT_EXTENTS)
+ #define EXT3_FEATURE_RO_COMPAT_SUPP   (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+                                        EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
++                                       EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
+                                        EXT4_FEATURE_RO_COMPAT_DIR_NLINK| \
+                                        EXT3_FEATURE_RO_COMPAT_BTREE_DIR)
+Index: linux-2.6.18.8.orig/fs/ext3/resize.c
+===================================================================
+--- linux-2.6.18.8.orig.orig/fs/ext3/resize.c  2007-06-21 14:53:15.000000000 +0200
++++ linux-2.6.18.8.orig/fs/ext3/resize.c       2007-07-02 11:09:26.000000000 +0200
+@@ -18,6 +18,7 @@
+ #include <linux/errno.h>
+ #include <linux/slab.h>
++#include "group.h"
+ #define outside(b, first, last)       ((b) < (first) || (b) >= (last))
+ #define inside(b, first, last)        ((b) >= (first) && (b) < (last))
+@@ -822,6 +823,7 @@ int ext3_group_add(struct super_block *s
+       gdp->bg_inode_table = cpu_to_le32(input->inode_table);
+       gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
+       gdp->bg_free_inodes_count = cpu_to_le16(EXT3_INODES_PER_GROUP(sb));
++      gdp->bg_checksum = ext3_group_desc_csum(sbi, input->group, gdp);
+       /*
+        * Make the new blocks and inodes valid next.  We do this before
+Index: linux-2.6.18.8.orig/fs/ext3/super.c
+===================================================================
+--- linux-2.6.18.8.orig.orig/fs/ext3/super.c   2007-07-02 11:09:26.000000000 +0200
++++ linux-2.6.18.8.orig/fs/ext3/super.c        2007-07-02 11:18:04.000000000 +0200
+@@ -41,6 +41,7 @@
+ #include "xattr.h"
+ #include "acl.h"
+ #include "namei.h"
++#include "group.h"
+ static int ext3_load_journal(struct super_block *, struct ext3_super_block *,
+                            unsigned long journal_devnum);
+@@ -1225,6 +1226,91 @@ static int ext3_setup_super(struct super
+       return res;
+ }
++#if !defined(CONFIG_CRC16) && !defined(CONFIG_CRC16_MODULE)
++/** CRC table for the CRC-16. The poly is 0x8005 (x^16 + x^15 + x^2 + 1) */
++__u16 const crc16_table[256] = {
++      0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
++      0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
++      0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
++      0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
++      0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
++      0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
++      0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
++      0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
++      0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
++      0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
++      0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
++      0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
++      0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
++      0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
++      0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
++      0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
++      0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
++      0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
++      0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
++      0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
++      0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
++      0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
++      0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
++      0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
++      0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
++      0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
++      0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
++      0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
++      0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
++      0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
++      0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
++      0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
++};
++
++static inline __u16 crc16_byte(__u16 crc, const __u8 data)
++{
++      return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
++}
++
++__u16 crc16(__u16 crc, __u8 const *buffer, size_t len)
++{
++      while (len--)
++              crc = crc16_byte(crc, *buffer++);
++      return crc;
++}
++#endif
++
++__le16 ext3_group_desc_csum(struct ext3_sb_info *sbi, __u32 block_group,
++                          struct ext3_group_desc *gdp)
++{
++      __u16 crc = 0;
++
++      if (sbi->s_es->s_feature_ro_compat &
++          cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
++              int offset = offsetof(struct ext3_group_desc, bg_checksum);
++              __le32 le_group = cpu_to_le32(block_group);
++
++              crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
++              crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
++              crc = crc16(crc, (__u8 *)gdp, offset);
++              offset += sizeof(gdp->bg_checksum); /* skip checksum */
++              BUG_ON(offset != sizeof(*gdp)); /* XXX handle s_desc_size */
++              /* for checksum of struct ext4_group_desc do the rest...
++              if ((sbi->s_es->s_feature_incompat &
++                   cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
++                   offset < le16_to_cpu(sbi->s_es->s_desc_size)) {
++                      crc = crc16(crc, (__u8 *)gdp + offset,
++                                  le16_to_cpu(sbi->s_es->s_desc_size) -
++                                  offset);
++              */
++      }
++
++      return cpu_to_le16(crc);
++}
++
++int ext3_group_desc_csum_verify(struct ext3_sb_info *sbi, __u32 block_group,
++                              struct ext3_group_desc *gdp)
++{
++      return (gdp->bg_checksum ==
++                      ext3_group_desc_csum(sbi, block_group, gdp));
++}
++
+ /* Called at mount-time, super-block is locked */
+ static int ext3_check_descriptors (struct super_block * sb)
+ {
+@@ -1274,6 +1360,13 @@ static int ext3_check_descriptors (struc
+                                       le32_to_cpu(gdp->bg_inode_table));
+                       return 0;
+               }
++              if (!ext3_group_desc_csum_verify(sbi, i, gdp)) {
++                      ext3_error(sb, __FUNCTION__,
++                                 "Checksum for group %d failed (%u!=%u)\n", i,
++                                 le16_to_cpu(ext3_group_desc_csum(sbi,i,gdp)),
++                                 le16_to_cpu(gdp->bg_checksum));
++                      return 0;
++              }
+               block += EXT3_BLOCKS_PER_GROUP(sb);
+               gdp++;
+       }
+Index: linux-2.6.18.8.orig/fs/ext3/group.h
+===================================================================
+--- /dev/null  1970-01-01 00:00:00.000000000 +0000
++++ linux-2.6.18.8.orig/fs/ext3/group.h        2007-07-02 11:09:26.000000000 +0200
+@@ -0,0 +1,29 @@
++/*
++ *  linux/fs/ext3/group.h
++ *
++ * Copyright (C) 2007 Cluster File Systems, Inc
++ *
++ * Author: Andreas Dilger <adilger@clusterfs.com>
++ */
++
++#ifndef _LINUX_EXT3_GROUP_H
++#define _LINUX_EXT3_GROUP_H
++#if defined(CONFIG_CRC16) || defined(CONFIG_CRC16_MODULE)
++#include <linux/crc16.h>
++#endif
++
++extern __le16 ext3_group_desc_csum(struct ext3_sb_info *sbi, __u32 group,
++                                 struct ext3_group_desc *gdp);
++extern int ext3_group_desc_csum_verify(struct ext3_sb_info *sbi, __u32 group,
++                                     struct ext3_group_desc *gdp);
++struct buffer_head *read_block_bitmap(struct super_block *sb,
++                                    unsigned int block_group);
++extern unsigned ext3_init_block_bitmap(struct super_block *sb,
++                                     struct buffer_head *bh, int group,
++                                     struct ext3_group_desc *desc);
++#define ext3_free_blocks_after_init(sb, group, desc)                  \
++              ext3_init_block_bitmap(sb, NULL, group, desc)
++extern unsigned ext3_init_inode_bitmap(struct super_block *sb,
++                                     struct buffer_head *bh, int group,
++                                     struct ext3_group_desc *desc);
++#endif /* _LINUX_EXT3_GROUP_H */
+Index: linux-2.6.18.8.orig/fs/ext3/ialloc.c
+===================================================================
+--- linux-2.6.18.8.orig.orig/fs/ext3/ialloc.c  2007-07-02 11:09:26.000000000 +0200
++++ linux-2.6.18.8.orig/fs/ext3/ialloc.c       2007-07-02 11:19:43.000000000 +0200
+@@ -28,6 +28,7 @@
+ #include "xattr.h"
+ #include "acl.h"
++#include "group.h"
+ /*
+  * ialloc.c contains the inodes allocation and deallocation routines
+@@ -43,6 +44,52 @@
+  * the free blocks count in the block.
+  */
++/*
++ * To avoid calling the atomic setbit hundreds or thousands of times, we only
++ * need to use it within a single byte (to ensure we get endianness right).
++ * We can use memset for the rest of the bitmap as there are no other users.
++ */
++static void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
++{
++      int i;
++
++      if (start_bit >= end_bit)
++              return;
++
++      ext3_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
++      for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
++              ext3_set_bit(i, bitmap);
++      if (i < end_bit)
++              memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
++}
++
++/* Initializes an uninitialized inode bitmap */
++unsigned ext3_init_inode_bitmap(struct super_block *sb,
++                              struct buffer_head *bh, int block_group,
++                              struct ext3_group_desc *gdp)
++{
++      struct ext3_sb_info *sbi = EXT3_SB(sb);
++
++      J_ASSERT_BH(bh, buffer_locked(bh));
++
++      /* If checksum is bad mark all blocks and inodes used to prevent
++       * allocation, essentially implementing a per-group read-only flag. */
++      if (!ext3_group_desc_csum_verify(sbi, block_group, gdp)) {
++              ext3_error(sb, __FUNCTION__, "Checksum bad for group %u\n",
++                         block_group);
++              gdp->bg_free_blocks_count = 0;
++              gdp->bg_free_inodes_count = 0;
++              gdp->bg_itable_unused = 0;
++              memset(bh->b_data, 0xff, sb->s_blocksize);
++              return 0;
++      }
++
++      memset(bh->b_data, 0, (EXT3_INODES_PER_GROUP(sb) + 7) / 8);
++      mark_bitmap_end(EXT3_INODES_PER_GROUP(sb), EXT3_BLOCKS_PER_GROUP(sb),
++                      bh->b_data);
++
++      return EXT3_INODES_PER_GROUP(sb);
++}
+ /*
+  * Read the inode allocation bitmap for a given block_group, reading
+@@ -59,8 +106,19 @@ read_inode_bitmap(struct super_block * s
+       desc = ext3_get_group_desc(sb, block_group, NULL);
+       if (!desc)
+               goto error_out;
+-
+-      bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
++      if (desc->bg_flags & cpu_to_le16(EXT3_BG_INODE_UNINIT)) {
++              bh = sb_getblk(sb, le32_to_cpu(desc->bg_inode_bitmap));
++              if (!buffer_uptodate(bh)) {
++                      lock_buffer(bh);
++                      if (!buffer_uptodate(bh)) {
++                              ext3_init_inode_bitmap(sb, bh,block_group,desc);
++                              set_buffer_uptodate(bh);
++                      }
++                      unlock_buffer(bh);
++              }
++      } else {
++              bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
++      }
+       if (!bh)
+               ext3_error(sb, "read_inode_bitmap",
+                           "Cannot read inode bitmap - "
+@@ -169,6 +227,8 @@ void ext3_free_inode (handle_t *handle, 
+                       if (is_directory)
+                               gdp->bg_used_dirs_count = cpu_to_le16(
+                                 le16_to_cpu(gdp->bg_used_dirs_count) - 1);
++                      gdp->bg_checksum = ext3_group_desc_csum(sbi,block_group,
++                                                              gdp);
+                       spin_unlock(sb_bgl_lock(sbi, block_group));
+                       percpu_counter_inc(&sbi->s_freeinodes_counter);
+                       if (is_directory)
+@@ -454,7 +514,7 @@ struct inode *ext3_new_inode(handle_t *h
+       struct ext3_sb_info *sbi;
+       int err = 0;
+       struct inode *ret;
+-      int i;
++      int i, free = 0;
+       /* Cannot create files in a deleted directory */
+       if (!dir || !dir->i_nlink)
+@@ -571,11 +631,13 @@ repeat_in_this_group:
+       goto out;
+ got:
+-      ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
+-      if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+-              ext3_error (sb, "ext3_new_inode",
+-                          "reserved inode or inode > inodes count - "
+-                          "block_group = %d, inode=%lu", group, ino);
++      ino++;
++      if ((group == 0 && ino < EXT3_FIRST_INO(sb)) ||
++          ino > EXT3_INODES_PER_GROUP(sb)) {
++              ext3_error(sb, __FUNCTION__,
++                         "reserved inode or inode > inodes count - "
++                         "block_group = %d, inode=%lu", group,
++                         ino + group * EXT3_INODES_PER_GROUP(sb));
+               err = -EIO;
+               goto fail;
+       }
+@@ -583,13 +645,64 @@ got:
+       BUFFER_TRACE(bh2, "get_write_access");
+       err = ext3_journal_get_write_access(handle, bh2);
+       if (err) goto fail;
++
++      /* We may have to initialize the block bitmap if it isn't already */
++      if (EXT3_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
++          gdp->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
++              struct buffer_head *block_bh = read_block_bitmap(sb, group);
++
++              BUFFER_TRACE(block_bh, "get block bitmap access");
++              err = ext3_journal_get_write_access(handle, block_bh);
++              if (err) {
++                      brelse(block_bh);
++                      goto fail;
++              }
++
++              free = 0;
++              spin_lock(sb_bgl_lock(sbi, group));
++              /* recheck and clear flag under lock if we still need to */
++              if (gdp->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
++                      gdp->bg_flags &= cpu_to_le16(~EXT3_BG_BLOCK_UNINIT);
++                      free = ext3_free_blocks_after_init(sb, group, gdp);
++                      gdp->bg_free_blocks_count = cpu_to_le16(free);
++              }
++              spin_unlock(sb_bgl_lock(sbi, group));
++
++              /* Don't need to dirty bitmap block if we didn't change it */
++              if (free) {
++                      BUFFER_TRACE(block_bh, "dirty block bitmap");
++                      err = ext3_journal_dirty_metadata(handle, block_bh);
++              }
++
++              brelse(block_bh);
++              if (err)
++                      goto fail;
++      }
++
+       spin_lock(sb_bgl_lock(sbi, group));
++      /* If we didn't allocate from within the initialized part of the inode
++       * table then we need to initialize up to this inode. */
++      if (EXT3_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
++              if (gdp->bg_flags & cpu_to_le16(EXT3_BG_INODE_UNINIT)) {
++                      gdp->bg_flags &= cpu_to_le16(~EXT3_BG_INODE_UNINIT);
++                      free = EXT3_INODES_PER_GROUP(sb);
++              } else {
++                      free = EXT3_INODES_PER_GROUP(sb) -
++                              le16_to_cpu(gdp->bg_itable_unused);
++              }
++
++              if (ino > free)
++                      gdp->bg_itable_unused =
++                              cpu_to_le16(EXT3_INODES_PER_GROUP(sb) - ino);
++      }
++
+       gdp->bg_free_inodes_count =
+               cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
+       if (S_ISDIR(mode)) {
+               gdp->bg_used_dirs_count =
+                       cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
+       }
++      gdp->bg_checksum = ext3_group_desc_csum(sbi, group, gdp);
+       spin_unlock(sb_bgl_lock(sbi, group));
+       BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
+       err = ext3_journal_dirty_metadata(handle, bh2);
+@@ -611,7 +724,7 @@ got:
+               inode->i_gid = current->fsgid;
+       inode->i_mode = mode;
+-      inode->i_ino = ino;
++      inode->i_ino = ino + group * EXT3_INODES_PER_GROUP(sb);
+       /* This is the optimal IO size (for stat), not the fs block size */
+       inode->i_blksize = PAGE_SIZE;
+       inode->i_blocks = 0;
+Index: linux-2.6.18.8.orig/fs/ext3/mballoc.c
+===================================================================
+--- linux-2.6.18.8.orig.orig/fs/ext3/mballoc.c 2007-07-02 11:09:25.000000000 +0200
++++ linux-2.6.18.8.orig/fs/ext3/mballoc.c      2007-07-02 11:09:26.000000000 +0200
+@@ -36,6 +36,8 @@
+ #include <linux/seq_file.h>
+ #include <linux/version.h>
++#include "group.h"
++
+ /*
+  * MUSTDO:
+  *   - test ext3_ext_search_left() and ext3_ext_search_right()
+@@ -323,6 +325,7 @@ struct ext3_group_info {
+       unsigned long   bb_state;
+       unsigned long   bb_tid;
+       struct ext3_free_metadata *bb_md_cur;
++      struct ext3_group_desc *bb_gdp;
+       unsigned short  bb_first_free;
+       unsigned short  bb_free;
+       unsigned short  bb_fragments;
+@@ -943,10 +946,7 @@ static int ext3_mb_init_cache(struct pag
+               if (first_group + i >= EXT3_SB(sb)->s_groups_count)
+                       break;
+-              err = -EIO;
+-              desc = ext3_get_group_desc(sb, first_group + i, NULL);
+-              if (desc == NULL)
+-                      goto out;
++              desc = EXT3_GROUP_INFO(sb, first_group + i)->bb_gdp;
+               err = -ENOMEM;
+               bh[i] = sb_getblk(sb, le32_to_cpu(desc->bg_block_bitmap));
+@@ -961,7 +961,12 @@ static int ext3_mb_init_cache(struct pag
+                       unlock_buffer(bh[i]);
+                       continue;
+               }
+-
++              if (desc->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
++                      ext3_init_block_bitmap(sb, bh[i], first_group + i,desc);
++                      set_buffer_uptodate(bh[i]);
++                      unlock_buffer(bh[i]);
++                      continue;
++              }
+               get_bh(bh[i]);
+               bh[i]->b_end_io = end_buffer_read_sync;
+               submit_bh(READ, bh[i]);
+@@ -1732,6 +1737,10 @@ static int ext3_mb_good_group(struct ext
+       switch (cr) {
+               case 0:
+                       BUG_ON(ac->ac_2order == 0);
++                      /* If this group is uninitialized, skip it initially */
++                      if (grp->bb_gdp->bg_flags &
++                          cpu_to_le16(EXT3_BG_BLOCK_UNINIT))
++                              return 0;
+                       bits = ac->ac_sb->s_blocksize_bits + 1;
+                       for (i = ac->ac_2order; i <= bits; i++)
+                               if (grp->bb_counters[i] > 0)
+@@ -1825,7 +1834,9 @@ repeat:
+                       }
+                       ac->ac_groups_scanned++;
+-                      if (cr == 0)
++                      if (cr == 0 || (e3b.bd_info->bb_gdp->bg_flags &
++                                      cpu_to_le16(EXT3_BG_BLOCK_UNINIT) &&
++                                      ac->ac_2order != 0))
+                               ext3_mb_simple_scan_group(ac, &e3b);
+                       else if (cr == 1 && ac->ac_g_ex.fe_len == sbi->s_stripe)
+                               ext3_mb_scan_aligned(ac, &e3b);
+@@ -2304,12 +2315,13 @@ int ext3_mb_init_backend(struct super_bl
+                       i--;
+                       goto err_freebuddy;
+               }
++              memset(meta_group_info[j], 0, len);
+               desc = ext3_get_group_desc(sb, i, NULL);
++              meta_group_info[j]->bb_gdp = desc;
+               if (desc == NULL) {
+                       printk(KERN_ERR"EXT3-fs: can't read descriptor %u\n",i);
+                       goto err_freebuddy;
+               }
+-              memset(meta_group_info[j], 0, len);
+               set_bit(EXT3_GROUP_INFO_NEED_INIT_BIT,
+                       &meta_group_info[j]->bb_state);
+@@ -2972,9 +2984,17 @@ int ext3_mb_mark_diskspace_used(struct e
+       mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
+       spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
++      if (gdp->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
++              gdp->bg_flags &= cpu_to_le16(~EXT3_BG_BLOCK_UNINIT);
++              gdp->bg_free_blocks_count =
++                      cpu_to_le16(ext3_free_blocks_after_init(sb,
++                                                          ac->ac_b_ex.fe_group,
++                                                          gdp));
++      }
+       gdp->bg_free_blocks_count =
+               cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)
+                               - ac->ac_b_ex.fe_len);
++      gdp->bg_checksum = ext3_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
+       spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+       percpu_counter_mod(&sbi->s_freeblocks_counter, - ac->ac_b_ex.fe_len);
+@@ -4343,6 +4363,7 @@ do_more:
+       spin_lock(sb_bgl_lock(sbi, block_group));
+       gdp->bg_free_blocks_count =
+               cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) + count);
++      gdp->bg_checksum = ext3_group_desc_csum(sbi, block_group, gdp);
+       spin_unlock(sb_bgl_lock(sbi, block_group));
+       percpu_counter_mod(&sbi->s_freeblocks_counter, count);
+Index: linux-2.6.18.8.orig/fs/ext3/balloc.c
+===================================================================
+--- linux-2.6.18.8.orig.orig/fs/ext3/balloc.c  2007-07-02 11:09:25.000000000 +0200
++++ linux-2.6.18.8.orig/fs/ext3/balloc.c       2007-07-02 11:09:26.000000000 +0200
+@@ -20,6 +20,7 @@
+ #include <linux/quotaops.h>
+ #include <linux/buffer_head.h>
++#include "group.h"
+ /*
+  * balloc.c contains the blocks allocation and deallocation routines
+  */
+@@ -73,6 +74,75 @@ struct ext3_group_desc * ext3_get_group_
+       return desc + offset;
+ }
++/* Initializes an uninitialized block bitmap if given, and returns the
++ * number of blocks free in the group. */
++unsigned ext3_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
++                              int block_group, struct ext3_group_desc *gdp)
++{
++      unsigned long start;
++      int bit, bit_max;
++      unsigned free_blocks;
++      struct ext3_sb_info *sbi = EXT3_SB(sb);
++
++      if (bh) {
++              J_ASSERT_BH(bh, buffer_locked(bh));
++
++              /* If checksum is bad mark all blocks use to prevent allocation,
++               * essentially implementing a per-group read-only flag. */
++              if (!ext3_group_desc_csum_verify(sbi, block_group, gdp)) {
++                      ext3_error(sb, __FUNCTION__,
++                                 "Checksum bad for group %u\n", block_group);
++                      gdp->bg_free_blocks_count = 0;
++                      gdp->bg_free_inodes_count = 0;
++                      gdp->bg_itable_unused = 0;
++                      memset(bh->b_data, 0xff, sb->s_blocksize);
++                      return 0;
++              }
++              memset(bh->b_data, 0, sb->s_blocksize);
++      }
++
++      /* Check for superblock and gdt backups in this group */
++      bit_max = ext3_bg_has_super(sb, block_group);
++
++      if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_META_BG) ||
++          block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) *
++                        sbi->s_desc_per_block) {
++              if (bit_max) {
++                      bit_max += ext3_bg_num_gdb(sb, block_group);
++                      bit_max +=le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
++              }
++      } else { /* For META_BG_BLOCK_GROUPS */
++              int group_rel = (block_group -
++                               le32_to_cpu(sbi->s_es->s_first_meta_bg)) %
++                              EXT3_DESC_PER_BLOCK(sb);
++              if (group_rel == 0 || group_rel == 1 ||
++                  (group_rel == EXT3_DESC_PER_BLOCK(sb) - 1))
++                      bit_max += 1;
++      }
++
++      /* Last and first groups are always initialized */
++      free_blocks = EXT3_BLOCKS_PER_GROUP(sb) - bit_max;
++
++      if (bh) {
++              for (bit = 0; bit < bit_max; bit++)
++                      ext3_set_bit(bit, bh->b_data);
++
++              start = block_group * EXT3_BLOCKS_PER_GROUP(sb) +
++                      le32_to_cpu(sbi->s_es->s_first_data_block);
++
++              /* Set bits for block and inode bitmaps, and inode table */
++              ext3_set_bit(le32_to_cpu(gdp->bg_block_bitmap) - start,
++                           bh->b_data);
++              ext3_set_bit(le32_to_cpu(gdp->bg_inode_bitmap) - start,
++                           bh->b_data);
++              for (bit = le32_to_cpu(gdp->bg_inode_table) - start,
++                   bit_max = bit + sbi->s_itb_per_group; bit < bit_max; bit++)
++                      ext3_set_bit(bit, bh->b_data);
++      }
++
++      return free_blocks - sbi->s_itb_per_group - 2;
++}
++
+ /*
+  * Read the bitmap for a given block_group, reading into the specified 
+  * slot in the superblock's bitmap cache.
+@@ -88,7 +158,19 @@ read_block_bitmap(struct super_block *sb
+       desc = ext3_get_group_desc (sb, block_group, NULL);
+       if (!desc)
+               goto error_out;
+-      bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
++      if (desc->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
++              bh = sb_getblk(sb, le32_to_cpu(desc->bg_block_bitmap));
++              if (!buffer_uptodate(bh)) {
++                      lock_buffer(bh);
++                      if (!buffer_uptodate(bh)) {
++                              ext3_init_block_bitmap(sb, bh,block_group,desc);
++                              set_buffer_uptodate(bh);
++                      }
++                      unlock_buffer(bh);
++              }
++      } else {
++              bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
++      }
+       if (!bh)
+               ext3_error (sb, "read_block_bitmap",
+                           "Cannot read block bitmap - "
+@@ -467,6 +549,7 @@ do_more:
+       desc->bg_free_blocks_count =
+               cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) +
+                       group_freed);
++      desc->bg_checksum = ext3_group_desc_csum(sbi, block_group, desc);
+       spin_unlock(sb_bgl_lock(sbi, block_group));
+       percpu_counter_mod(&sbi->s_freeblocks_counter, count);
+@@ -1433,8 +1516,11 @@ allocated:
+                       ret_block, goal_hits, goal_attempts);
+       spin_lock(sb_bgl_lock(sbi, group_no));
++      if (gdp->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT))
++              gdp->bg_flags &= cpu_to_le16(~EXT3_BG_BLOCK_UNINIT);
+       gdp->bg_free_blocks_count =
+                       cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - num);
++      gdp->bg_checksum = ext3_group_desc_csum(sbi, group_no, gdp);
+       spin_unlock(sb_bgl_lock(sbi, group_no));
+       percpu_counter_mod(&sbi->s_freeblocks_counter, -num);