From: "Darrick J. Wong" Subject: [PATCH 09/47] libext2fs: Create the inode bitmap checksum Date: Sat, 08 Oct 2011 00:34:13 -0700 Message-ID: <20111008073413.17888.75831.stgit@elm3c44.beaverton.ibm.com> References: <20111008073315.17888.22132.stgit@elm3c44.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Sunil Mushran , Amir Goldstein , Andi Kleen , Mingming Cao , Joel Becker , linux-ext4@vger.kernel.org, Coly Li To: Andreas Dilger , Theodore Tso , "Darrick J. Wong" Return-path: Received: from e7.ny.us.ibm.com ([32.97.182.137]:48781 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426Ab1JHHg2 (ORCPT ); Sat, 8 Oct 2011 03:36:28 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e7.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p986F56k013125 for ; Sat, 8 Oct 2011 02:15:05 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p987YFbn202108 for ; Sat, 8 Oct 2011 03:34:15 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p987YE05013061 for ; Sat, 8 Oct 2011 03:34:15 -0400 In-Reply-To: <20111008073315.17888.22132.stgit@elm3c44.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Provide a field in the block group descriptor to store inode bitmap checksum, and some helper functions to calculate and verify it. Signed-off-by: Darrick J. Wong --- lib/ext2fs/blknum.c | 15 +++++++++++++ lib/ext2fs/closefs.c | 29 +++++++++++++++----------- lib/ext2fs/csum.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ lib/ext2fs/ext2_fs.h | 4 ++++ lib/ext2fs/ext2fs.h | 6 +++++ lib/ext2fs/rw_bitmaps.c | 17 +++++++++++++++ 6 files changed, 112 insertions(+), 12 deletions(-) diff --git a/lib/ext2fs/blknum.c b/lib/ext2fs/blknum.c index fd203b4..30987fc 100644 --- a/lib/ext2fs/blknum.c +++ b/lib/ext2fs/blknum.c @@ -230,6 +230,21 @@ void ext2fs_block_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk) } /* + * Return the inode bitmap checksum of a group + */ +__u32 ext2fs_inode_bitmap_checksum(ext2_filsys fs, dgrp_t group) +{ + struct ext4_group_desc *gdp; + __u32 csum; + + gdp = ext4fs_group_desc(fs, fs->group_desc, group); + csum = gdp->bg_inode_bitmap_csum_lo; + if (fs->super->s_desc_size < EXT4_BG_INODE_BITMAP_CSUM_HI_LOCATION) + csum |= ((__u32)gdp->bg_inode_bitmap_csum_hi << 16); + return csum; +} + +/* * Return the inode bitmap block of a group */ blk64_t ext2fs_inode_bitmap_loc(ext2_filsys fs, dgrp_t group) diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c index 973c2a2..1867be3 100644 --- a/lib/ext2fs/closefs.c +++ b/lib/ext2fs/closefs.c @@ -288,6 +288,23 @@ errcode_t ext2fs_flush2(ext2_filsys fs, int flags) fs->super->s_wtime = fs->now ? fs->now : time(NULL); fs->super->s_block_group_nr = 0; + + /* + * If the write_bitmaps() function is present, call it to + * flush the bitmaps. This is done this way so that a simple + * program that doesn't mess with the bitmaps doesn't need to + * drag in the bitmaps.c code. + * + * Bitmap checksums live in the group descriptor, so the + * bitmaps need to be written before the descriptors. + */ + if (fs->write_bitmaps) { + retval = fs->write_bitmaps(fs); + if (retval) + goto errout; + } + + /* Prepare the group descriptors for writing */ #ifdef WORDS_BIGENDIAN retval = EXT2_ET_NO_MEMORY; retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super_shadow); @@ -378,18 +395,6 @@ errcode_t ext2fs_flush2(ext2_filsys fs, int flags) ext2fs_numeric_progress_close(fs, &progress, NULL); - /* - * If the write_bitmaps() function is present, call it to - * flush the bitmaps. This is done this way so that a simple - * program that doesn't mess with the bitmaps doesn't need to - * drag in the bitmaps.c code. - */ - if (fs->write_bitmaps) { - retval = fs->write_bitmaps(fs); - if (retval) - goto errout; - } - write_primary_superblock_only: /* * Write out master superblock. This has to be done diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c index b8945ad..91b1892 100644 --- a/lib/ext2fs/csum.c +++ b/lib/ext2fs/csum.c @@ -30,6 +30,59 @@ #define STATIC static #endif +static __u32 ext2fs_bitmap_csum(ext2_filsys fs, dgrp_t group, char *bitmap, + int size) +{ + __u32 crc; + + group = ext2fs_cpu_to_le32(group); + crc = ext2fs_crc32c_le(~0, fs->super->s_uuid, + sizeof(fs->super->s_uuid)); + crc = ext2fs_crc32c_le(crc, (unsigned char *)&group, sizeof(group)); + crc = ext2fs_crc32c_le(crc, (unsigned char *)bitmap, size); + + return crc; +} + +int ext2fs_inode_bitmap_csum_verify(ext2_filsys fs, dgrp_t group, + char *bitmap, int size) +{ + struct ext4_group_desc *gdp = (struct ext4_group_desc *) + ext2fs_group_desc(fs, fs->group_desc, group); + __u32 provided, calculated; + + if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return 1; + provided = gdp->bg_inode_bitmap_csum_lo; + calculated = ext2fs_bitmap_csum(fs, group, bitmap, size); + if (fs->super->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_LOCATION) + provided |= ((__u32)gdp->bg_inode_bitmap_csum_hi << 16); + else + calculated &= 0xFFFF; + + return provided == calculated; +} + +errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group, + char *bitmap, int size) +{ + __u32 crc; + struct ext4_group_desc *gdp = (struct ext4_group_desc *) + ext2fs_group_desc(fs, fs->group_desc, group); + + if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return 0; + + crc = ext2fs_bitmap_csum(fs, group, bitmap, size); + gdp->bg_inode_bitmap_csum_lo = crc & 0xFFFF; + if (fs->super->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_LOCATION) + gdp->bg_inode_bitmap_csum_hi = crc >> 16; + + return 0; +} + static errcode_t ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum, struct ext2_inode_large *inode, __u32 *crc) diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h index 6fd82f1..e7f8bb4 100644 --- a/lib/ext2fs/ext2_fs.h +++ b/lib/ext2fs/ext2_fs.h @@ -191,6 +191,10 @@ struct ext4_group_desc __u32 bg_reserved; }; +#define EXT4_BG_INODE_BITMAP_CSUM_HI_LOCATION \ + (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \ + sizeof(__u16)) + #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */ #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */ #define EXT2_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */ diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h index 04db632..d71181b 100644 --- a/lib/ext2fs/ext2fs.h +++ b/lib/ext2fs/ext2fs.h @@ -788,6 +788,7 @@ extern errcode_t ext2fs_get_block_bitmap_range2(ext2fs_block_bitmap bmap, void *out); /* blknum.c */ +extern __u32 ext2fs_inode_bitmap_checksum(ext2_filsys fs, dgrp_t group); extern dgrp_t ext2fs_group_of_blk2(ext2_filsys fs, blk64_t); extern blk64_t ext2fs_group_first_block2(ext2_filsys fs, dgrp_t group); extern blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group); @@ -818,6 +819,7 @@ extern struct ext2_group_desc *ext2fs_group_desc(ext2_filsys fs, extern blk64_t ext2fs_block_bitmap_loc(ext2_filsys fs, dgrp_t group); extern void ext2fs_block_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk); +extern __u32 ext2fs_inode_bitmap_csum(ext2_filsys fs, dgrp_t group); extern blk64_t ext2fs_inode_bitmap_loc(ext2_filsys fs, dgrp_t group); extern void ext2fs_inode_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk); @@ -925,6 +927,10 @@ extern __u32 ext2fs_crc32c_be(__u32 crc, unsigned char const *p, size_t len); extern __u32 ext2fs_crc32c_le(__u32 crc, unsigned char const *p, size_t len); /* csum.c */ +extern errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group, + char *bitmap, int size); +extern int ext2fs_inode_bitmap_csum_verify(ext2_filsys fs, dgrp_t group, + char *bitmap, int size); extern errcode_t ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum, struct ext2_inode_large *inode); extern int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum, diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c index 1d5f7b2..a325fdb 100644 --- a/lib/ext2fs/rw_bitmaps.c +++ b/lib/ext2fs/rw_bitmaps.c @@ -117,6 +117,12 @@ static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block) if (retval) goto errout; + retval = ext2fs_inode_bitmap_csum_set(fs, i, inode_buf, + inode_nbytes); + if (retval) + goto errout; + ext2fs_group_desc_csum_set(fs, i); + blk = ext2fs_inode_bitmap_loc(fs, i); if (blk) { retval = io_channel_write_blk64(fs->io, blk, 1, @@ -163,6 +169,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block) blk64_t blk_cnt; ext2_ino_t ino_itr = 1; ext2_ino_t ino_cnt; + struct ext4_group_desc *gdp; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); @@ -288,6 +295,16 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block) retval = EXT2_ET_INODE_BITMAP_READ; goto cleanup; } + + /* verify inode bitmap checksum */ + gdp = (struct ext4_group_desc *) + ext2fs_group_desc(fs, fs->group_desc, + i); + if (!(fs->flags & + EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_bitmap_csum_verify(fs, i, + inode_bitmap, inode_nbytes)) + return EXT2_ET_INODE_BITMAP_READ; } else memset(inode_bitmap, 0, inode_nbytes); cnt = inode_nbytes << 3;