From: Avantika Mathur Subject: [PATCH] uninitialized block groups Date: Wed, 22 Aug 2007 22:41:18 -0700 Message-ID: <46CD1DFE.1030907@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------090100090708080403060206" To: Andreas Dilger , linux-ext4@vger.kernel.org Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:46903 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750978AbXHWFkf (ORCPT ); Thu, 23 Aug 2007 01:40:35 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e32.co.us.ibm.com (8.12.11.20060308/8.13.8) with ESMTP id l7N4XYvZ016812 for ; Thu, 23 Aug 2007 00:33:34 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l7N5eW8S210970 for ; Wed, 22 Aug 2007 23:40:32 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l7N5eVDM031293 for ; Wed, 22 Aug 2007 23:40:32 -0600 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org This is a multi-part message in MIME format. --------------090100090708080403060206 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Below is an updated version of the uninitialized block groups patch, ported to the end of the patch queue. There are small changes to the previous version: - consistent format of the group_desc structure with the e2fsprogs patches - do not verify group_desc checksums if the feature is not enabled I have tested the patch with the e2fsprogs patches sent by Kalpak, and ran fsx. thanks Avantika --- --------------090100090708080403060206 Content-Type: text/plain; name="uninit" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="uninit" From: Andreas Dilger Signed-off-by: Avantika Mathur --- Index: linux-2.6.23-rc3/fs/ext4/balloc.c =================================================================== --- linux-2.6.23-rc3.orig/fs/ext4/balloc.c 2007-08-21 17:31:50.000000000 -0700 +++ linux-2.6.23-rc3/fs/ext4/balloc.c 2007-08-21 17:31:51.000000000 -0700 @@ -20,6 +20,7 @@ #include #include +#include "group.h" /* * balloc.c contains the blocks allocation and deallocation routines */ @@ -42,6 +43,75 @@ void ext4_get_group_no_and_offset(struct } +/* Initializes an uninitialized block bitmap if given, and returns the + * number of blocks free in the group. */ +unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, + int block_group, struct ext4_group_desc *gdp) +{ + unsigned long start; + int bit, bit_max; + unsigned free_blocks; + struct ext4_sb_info *sbi = EXT4_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 (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { + ext4_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 = ext4_bg_has_super(sb, block_group); + + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_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 += ext4_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)) % + EXT4_DESC_PER_BLOCK(sb); + if (group_rel == 0 || group_rel == 1 || + (group_rel == EXT4_DESC_PER_BLOCK(sb) - 1)) + bit_max += 1; + } + + /* Last and first groups are always initialized */ + free_blocks = EXT4_BLOCKS_PER_GROUP(sb) - bit_max; + + if (bh) { + for (bit = 0; bit < bit_max; bit++) + ext4_set_bit(bit, bh->b_data); + + start = block_group * EXT4_BLOCKS_PER_GROUP(sb) + + le32_to_cpu(sbi->s_es->s_first_data_block); + + /* Set bits for block and inode bitmaps, and inode table */ + ext4_set_bit(le32_to_cpu(gdp->bg_block_bitmap) - start, + bh->b_data); + ext4_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++) + ext4_set_bit(bit, bh->b_data); + } + + return free_blocks - sbi->s_itb_per_group - 2; +} + /* * The free blocks are managed by bitmaps. A file system contains several * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap @@ -116,10 +186,22 @@ read_block_bitmap(struct super_block *sb struct ext4_group_desc * desc; struct buffer_head * bh = NULL; - desc = ext4_get_group_desc (sb, block_group, NULL); + desc = ext4_get_group_desc(sb, block_group, NULL); if (!desc) goto error_out; - bh = sb_bread(sb, ext4_block_bitmap(sb, desc)); + if (desc->bg_flags & cpu_to_le16(EXT4_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)) { + ext4_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) ext4_error (sb, "read_block_bitmap", "Cannot read block bitmap - " @@ -588,6 +670,7 @@ do_more: desc->bg_free_blocks_count = cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) + group_freed); + desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); spin_unlock(sb_bgl_lock(sbi, block_group)); percpu_counter_mod(&sbi->s_freeblocks_counter, count); @@ -1656,8 +1739,11 @@ allocated: ret_block, goal_hits, goal_attempts); spin_lock(sb_bgl_lock(sbi, group_no)); + if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) + gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); gdp->bg_free_blocks_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)-num); + gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp); spin_unlock(sb_bgl_lock(sbi, group_no)); percpu_counter_mod(&sbi->s_freeblocks_counter, -num); Index: linux-2.6.23-rc3/fs/ext4/group.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.23-rc3/fs/ext4/group.h 2007-08-22 21:30:55.000000000 -0700 @@ -0,0 +1,29 @@ +/* + * linux/fs/ext4/group.h + * + * Copyright (C) 2007 Cluster File Systems, Inc + * + * Author: Andreas Dilger + */ + +#ifndef _LINUX_EXT4_GROUP_H +#define _LINUX_EXT4_GROUP_H +#if defined(CONFIG_CRC16) +#include +#endif + +extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group, + struct ext4_group_desc *gdp); +extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group, + struct ext4_group_desc *gdp); +struct buffer_head *read_block_bitmap(struct super_block *sb, + unsigned int block_group); +extern unsigned ext4_init_block_bitmap(struct super_block *sb, + struct buffer_head *bh, int group, + struct ext4_group_desc *desc); +#define ext4_free_blocks_after_init(sb, group, desc) \ + ext4_init_block_bitmap(sb, NULL, group, desc) +extern unsigned ext4_init_inode_bitmap(struct super_block *sb, + struct buffer_head *bh, int group, + struct ext4_group_desc *desc); +#endif /* _LINUX_EXT4_GROUP_H */ Index: linux-2.6.23-rc3/fs/ext4/ialloc.c =================================================================== --- linux-2.6.23-rc3.orig/fs/ext4/ialloc.c 2007-08-12 21:25:24.000000000 -0700 +++ linux-2.6.23-rc3/fs/ext4/ialloc.c 2007-08-21 17:31:51.000000000 -0700 @@ -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; + + ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); + for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) + ext4_set_bit(i, bitmap); + if (i < end_bit) + memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); +} + +/* Initializes an uninitialized inode bitmap */ +unsigned ext4_init_inode_bitmap(struct super_block *sb, + struct buffer_head *bh, int block_group, + struct ext4_group_desc *gdp) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + + J_ASSERT_BH(bh, buffer_locked(bh)); + + /* If checksum is bad mark all blocks and inodes use to prevent + * allocation, essentially implementing a per-group read-only flag. */ + if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { + ext4_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, (EXT4_INODES_PER_GROUP(sb) + 7) / 8); + mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb), + bh->b_data); + + return EXT4_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 = ext4_get_group_desc(sb, block_group, NULL); if (!desc) goto error_out; - - bh = sb_bread(sb, ext4_inode_bitmap(sb, desc)); + if (desc->bg_flags & cpu_to_le16(EXT4_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)) { + ext4_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) ext4_error(sb, "read_inode_bitmap", "Cannot read inode bitmap - " @@ -169,6 +227,8 @@ void ext4_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 = ext4_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) @@ -438,7 +498,7 @@ struct inode *ext4_new_inode(handle_t *h struct ext4_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) @@ -520,11 +580,13 @@ repeat_in_this_group: goto out; got: - ino += group * EXT4_INODES_PER_GROUP(sb) + 1; - if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { - ext4_error (sb, "ext4_new_inode", - "reserved inode or inode > inodes count - " - "block_group = %d, inode=%lu", group, ino); + ino++; + if ((group == 0 && ino < EXT4_FIRST_INO(sb)) || + ino > EXT4_INODES_PER_GROUP(sb)) { + ext4_error(sb, __FUNCTION__, + "reserved inode or inode > inodes count - " + "block_group = %d, inode=%lu", group, + ino + group * EXT4_INODES_PER_GROUP(sb)); err = -EIO; goto fail; } @@ -532,13 +594,65 @@ got: BUFFER_TRACE(bh2, "get_write_access"); err = ext4_journal_get_write_access(handle, bh2); if (err) goto fail; + + /* We may have to initialize the block bitmap if it isn't already */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && + gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { + struct buffer_head *block_bh = read_block_bitmap(sb, group); + + BUFFER_TRACE(block_bh, "get block bitmap access"); + err = ext4_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(EXT4_BG_BLOCK_UNINIT)) { + gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); + free = ext4_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 = ext4_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 (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { + if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { + gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); + free = EXT4_INODES_PER_GROUP(sb); + } else { + free = EXT4_INODES_PER_GROUP(sb) - + le16_to_cpu(gdp->bg_itable_unused); + } + + if (ino > free) { + gdp->bg_itable_unused = + cpu_to_le16(EXT4_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 = ext4_group_desc_csum(sbi, group, gdp); spin_unlock(sb_bgl_lock(sbi, group)); BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata"); err = ext4_journal_dirty_metadata(handle, bh2); @@ -560,7 +674,7 @@ got: inode->i_gid = current->fsgid; inode->i_mode = mode; - inode->i_ino = ino; + inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb); /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = Index: linux-2.6.23-rc3/fs/ext4/resize.c =================================================================== --- linux-2.6.23-rc3.orig/fs/ext4/resize.c 2007-08-12 21:25:24.000000000 -0700 +++ linux-2.6.23-rc3/fs/ext4/resize.c 2007-08-21 17:31:51.000000000 -0700 @@ -16,6 +16,7 @@ #include #include +#include "group.h" #define outside(b, first, last) ((b) < (first) || (b) >= (last)) #define inside(b, first, last) ((b) >= (first) && (b) < (last)) @@ -842,6 +843,7 @@ int ext4_group_add(struct super_block *s ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */ gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count); gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb)); + gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); /* * Make the new blocks and inodes valid next. We do this before Index: linux-2.6.23-rc3/fs/ext4/super.c =================================================================== --- linux-2.6.23-rc3.orig/fs/ext4/super.c 2007-08-21 17:31:50.000000000 -0700 +++ linux-2.6.23-rc3/fs/ext4/super.c 2007-08-22 21:32:27.000000000 -0700 @@ -43,6 +43,7 @@ #include "xattr.h" #include "acl.h" #include "namei.h" +#include "group.h" static int ext4_load_journal(struct super_block *, struct ext4_super_block *, unsigned long journal_devnum); @@ -1271,6 +1272,94 @@ static int ext4_setup_super(struct super return res; } +#if !defined(CONFIG_CRC16) +/** CRC table for the CRC-16. The poly is 0x8005 (x16 + x15 + x2 + 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 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group, + struct ext4_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 ext4_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 */ + /* 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 ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group, + struct ext4_group_desc *gdp) +{ + if ((sbi->s_es->s_feature_ro_compat & + cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) && + (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp))) + return 0; + + return 1; +} + /* Called at mount-time, super-block is locked */ static int ext4_check_descriptors (struct super_block * sb) { @@ -1325,6 +1414,13 @@ static int ext4_check_descriptors (struc i, inode_table); return 0; } + if (!ext4_group_desc_csum_verify(sbi, i, gdp)) { + ext4_error(sb, __FUNCTION__, + "Checksum for group %d failed (%u!=%u)\n", i, + le16_to_cpu(ext4_group_desc_csum(sbi,i,gdp)), + le16_to_cpu(gdp->bg_checksum)); + return 0; + } first_block += EXT4_BLOCKS_PER_GROUP(sb); gdp = (struct ext4_group_desc *) ((__u8 *)gdp + EXT4_DESC_SIZE(sb)); Index: linux-2.6.23-rc3/include/linux/ext4_fs.h =================================================================== --- linux-2.6.23-rc3.orig/include/linux/ext4_fs.h 2007-08-21 17:31:50.000000000 -0700 +++ linux-2.6.23-rc3/include/linux/ext4_fs.h 2007-08-21 17:31:51.000000000 -0700 @@ -150,19 +150,25 @@ struct ext4_allocation_request { */ struct ext4_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_flags; - __u32 bg_reserved[3]; + __u32 bg_reserved[2]; + __le16 bg_itable_unused; /* Unused inodes count */ + __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ __le32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */ __le32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */ __le32 bg_inode_table_hi; /* Inodes table block MSB */ }; +#define EXT4_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not in use */ +#define EXT4_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not in use */ +#define EXT4_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */ + #ifdef __KERNEL__ #include #include @@ -734,6 +740,7 @@ static inline int ext4_valid_inum(struct #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 +#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040 @@ -755,6 +762,7 @@ static inline int ext4_valid_inum(struct EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \ EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \ EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \ + EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \ EXT4_FEATURE_RO_COMPAT_BTREE_DIR) /* --------------090100090708080403060206--