From: "Darrick J. Wong" Subject: [PATCH 05/51] libext2fs: Add inode checksum support Date: Sat, 07 Jan 2012 00:33:29 -0800 Message-ID: <20120107083329.25788.87868.stgit@elm3c44.beaverton.ibm.com> References: <20120107083256.25788.41238.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 e33.co.us.ibm.com ([32.97.110.151]:46815 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751660Ab2AGIdg (ORCPT ); Sat, 7 Jan 2012 03:33:36 -0500 Received: from /spool/local by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 7 Jan 2012 01:33:35 -0700 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q078XWKO149218 for ; Sat, 7 Jan 2012 01:33:32 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q078XUno011650 for ; Sat, 7 Jan 2012 01:33:32 -0700 In-Reply-To: <20120107083256.25788.41238.stgit@elm3c44.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: This patch adds the ability for the libext2fs functions to read and write the inode checksum. Signed-off-by: Darrick J. Wong --- lib/ext2fs/csum.c | 82 +++++++++++++++++++++++++++++++++++++++++++++ lib/ext2fs/ext2_err.et.in | 3 ++ lib/ext2fs/ext2_fs.h | 4 ++ lib/ext2fs/ext2fs.h | 4 ++ lib/ext2fs/inode.c | 40 ++++++++++++++++++---- lib/ext2fs/mkdir.c | 8 +++- 6 files changed, 131 insertions(+), 10 deletions(-) diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c index 596923e..5091a00 100644 --- a/lib/ext2fs/csum.c +++ b/lib/ext2fs/csum.c @@ -30,6 +30,88 @@ #define STATIC static #endif +static errcode_t ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum, + struct ext2_inode_large *inode, + __u32 *crc, int has_hi) +{ + __u32 gen; + struct ext2_inode_large *desc = inode; + size_t size = fs->super->s_inode_size; + __u16 old_lo; + __u16 old_hi = 0; + + old_lo = inode->i_checksum_lo; + inode->i_checksum_lo = 0; + if (has_hi) { + old_hi = inode->i_checksum_hi; + inode->i_checksum_hi = 0; + } + + inum = ext2fs_cpu_to_le32(inum); + gen = inode->i_generation; + *crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum, + sizeof(inum)); + *crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen)); + *crc = ext2fs_crc32c_le(*crc, (unsigned char *)desc, size); + + inode->i_checksum_lo = old_lo; + if (has_hi) + inode->i_checksum_hi = old_hi; + return 0; +} + +int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum, + struct ext2_inode_large *inode) +{ + errcode_t retval; + __u32 provided, calculated; + int has_hi; + + if (fs->super->s_creator_os != EXT2_OS_LINUX || + !EXT2_HAS_RO_COMPAT_FEATURE(fs->super, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return 1; + + has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE && + inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END); + + provided = ext2fs_le16_to_cpu(inode->i_checksum_lo); + retval = ext2fs_inode_csum(fs, inum, inode, &calculated, has_hi); + if (retval) + return 0; + if (has_hi) { + __u32 hi = ext2fs_le16_to_cpu(inode->i_checksum_hi); + provided |= hi << 16; + } else + calculated &= 0xFFFF; + + return provided == calculated; +} + +errcode_t ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum, + struct ext2_inode_large *inode) +{ + errcode_t retval; + __u32 crc; + int has_hi; + + if (fs->super->s_creator_os != EXT2_OS_LINUX || + !EXT2_HAS_RO_COMPAT_FEATURE(fs->super, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return 0; + + has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE && + inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END); + + retval = ext2fs_inode_csum(fs, inum, inode, &crc, has_hi); + if (retval) + return retval; + inode->i_checksum_lo = ext2fs_cpu_to_le16(crc & 0xFFFF); + if (has_hi) + inode->i_checksum_hi = ext2fs_cpu_to_le16(crc >> 16); + return 0; +} + STATIC __u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group) { __u16 crc = 0; diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in index ccf1894..d4a5b10 100644 --- a/lib/ext2fs/ext2_err.et.in +++ b/lib/ext2fs/ext2_err.et.in @@ -443,4 +443,7 @@ ec EXT2_ET_MMP_CHANGE_ABORT, ec EXT2_ET_MMP_OPEN_DIRECT, "MMP: open with O_DIRECT failed" +ec EXT2_ET_INODE_CSUM_INVALID, + "Inode checksum does not match inode" + end diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h index 4fb9485..ed648a9 100644 --- a/lib/ext2fs/ext2_fs.h +++ b/lib/ext2fs/ext2_fs.h @@ -459,6 +459,10 @@ struct ext2_inode_large { __u32 i_version_hi; /* high 32 bits for 64-bit version */ }; +#define EXT4_INODE_CSUM_HI_EXTRA_END \ + (offsetof(struct ext2_inode_large, i_checksum_hi) + sizeof(__u16) - \ + EXT2_GOOD_OLD_INODE_SIZE) + #define i_dir_acl i_size_high #if defined(__KERNEL__) || defined(__linux__) diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h index c00032e..858a338 100644 --- a/lib/ext2fs/ext2fs.h +++ b/lib/ext2fs/ext2fs.h @@ -939,6 +939,10 @@ 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_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, + struct ext2_inode_large *inode); extern void ext2fs_group_desc_csum_set(ext2_filsys fs, dgrp_t group); extern int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group); extern errcode_t ext2fs_set_gdt_csum(ext2_filsys fs); diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c index a4f6670..74703c5 100644 --- a/lib/ext2fs/inode.c +++ b/lib/ext2fs/inode.c @@ -417,7 +417,7 @@ errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, errcode_t retval; int extra_bytes = 0; const int length = EXT2_INODE_SIZE(scan->fs->super); - struct ext2_inode *iptr = inode; + struct ext2_inode_large *iptr = (struct ext2_inode_large *)inode; EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN); @@ -493,6 +493,12 @@ errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, scan->ptr += scan->inode_size - extra_bytes; scan->bytes_left -= scan->inode_size - extra_bytes; + /* Verify the inode checksum. */ + if (!(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1, + (struct ext2_inode_large *)scan->temp_buffer)) + retval = EXT2_ET_INODE_CSUM_INVALID; + #ifdef WORDS_BIGENDIAN memset(iptr, 0, length); ext2fs_swap_inode_full(scan->fs, @@ -506,6 +512,12 @@ errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE; scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES; } else { + /* Verify the inode checksum. */ + if (!(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1, + (struct ext2_inode_large *)scan->ptr)) + retval = EXT2_ET_INODE_CSUM_INVALID; + #ifdef WORDS_BIGENDIAN memset(iptr, 0, length); ext2fs_swap_inode_full(scan->fs, @@ -524,7 +536,7 @@ errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, scan->inodes_left--; scan->current_inode++; *ino = scan->current_inode; - if (inode != iptr) { + if (iptr != (struct ext2_inode_large *)inode) { memcpy(inode, iptr, bufsize); ext2fs_free_mem(&iptr); } @@ -551,7 +563,7 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, int clen, i, inodes_per_block; io_channel io; int length = EXT2_INODE_SIZE(fs->super); - struct ext2_inode *iptr; + struct ext2_inode_large *iptr; int cache_slot; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); @@ -600,7 +612,7 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, offset &= (EXT2_BLOCK_SIZE(fs->super) - 1); cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size; - iptr = fs->icache->cache[cache_slot].inode; + iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode; ptr = (char *) iptr; while (length) { @@ -626,6 +638,11 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, } length = EXT2_INODE_SIZE(fs->super); + /* Verify the inode checksum. */ + if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_csum_verify(fs, ino, iptr)) + return EXT2_ET_INODE_CSUM_INVALID; + #ifdef WORDS_BIGENDIAN ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr, (struct ext2_inode_large *) iptr, @@ -674,12 +691,17 @@ errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino, retval = ext2fs_get_mem(length, &w_inode); if (retval) return retval; - if (bufsize < length) + + if (bufsize < length) { + int old_flags = fs->flags; + fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS; retval = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)w_inode, length); - if (retval) - goto errout; + fs->flags = old_flags; + if (retval) + goto errout; + } /* Check to see if the inode cache needs to be updated */ if (fs->icache) { @@ -706,6 +728,10 @@ errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino, ext2fs_swap_inode_full(fs, w_inode, w_inode, 1, length); #endif + retval = ext2fs_inode_csum_set(fs, ino, w_inode); + if (retval) + goto errout; + group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super); offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) * EXT2_INODE_SIZE(fs->super); diff --git a/lib/ext2fs/mkdir.c b/lib/ext2fs/mkdir.c index b12bf2d..861ddab 100644 --- a/lib/ext2fs/mkdir.c +++ b/lib/ext2fs/mkdir.c @@ -93,12 +93,14 @@ errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum, inode.i_size = fs->blocksize; /* - * Write out the inode and inode data block + * Write out the inode and inode data block. The inode generation + * number is assigned by write_new_inode, which means that the call + * to write_dir_block must come after that. */ - retval = ext2fs_write_dir_block(fs, blk, block); + retval = ext2fs_write_new_inode(fs, ino, &inode); if (retval) goto cleanup; - retval = ext2fs_write_new_inode(fs, ino, &inode); + retval = ext2fs_write_dir_block(fs, blk, block); if (retval) goto cleanup;