From patchwork Sat Oct 8 07:54:49 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 118491 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D5467B70D6 for ; Sat, 8 Oct 2011 19:01:57 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751240Ab1JHIBn (ORCPT ); Sat, 8 Oct 2011 04:01:43 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:41775 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753948Ab1JHH5e (ORCPT ); Sat, 8 Oct 2011 03:57:34 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e39.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p987cwRA011616; Sat, 8 Oct 2011 01:38:58 -0600 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p987sqOb178164; Sat, 8 Oct 2011 01:54:52 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p987spkk006907; Sat, 8 Oct 2011 01:54:52 -0600 Received: from elm3c44.beaverton.ibm.com ([9.47.69.44]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p987soUH006872; Sat, 8 Oct 2011 01:54:50 -0600 Subject: [PATCH 10/28] ext4: Calculate and verify superblock checksum To: Andreas Dilger , Theodore Tso , "Darrick J. Wong" From: "Darrick J. Wong" Cc: Sunil Mushran , Martin K Petersen , Greg Freemyer , Amir Goldstein , linux-kernel , Andi Kleen , Mingming Cao , Joel Becker , linux-fsdevel , linux-ext4@vger.kernel.org, Coly Li Date: Sat, 08 Oct 2011 00:54:49 -0700 Message-ID: <20111008075449.20506.10158.stgit@elm3c44.beaverton.ibm.com> In-Reply-To: <20111008075343.20506.23155.stgit@elm3c44.beaverton.ibm.com> References: <20111008075343.20506.23155.stgit@elm3c44.beaverton.ibm.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Calculate and verify the superblock checksum. Since the UUID and block group number are embedded in each copy of the superblock, we need only checksum the entire block. Refactor some of the code to eliminate open-coding of the checksum update call. Signed-off-by: Darrick J. Wong --- fs/ext4/ext4.h | 11 ++++++++++- fs/ext4/ext4_jbd2.c | 9 ++++++++- fs/ext4/ext4_jbd2.h | 7 +++++-- fs/ext4/inode.c | 3 +-- fs/ext4/namei.c | 4 ++-- fs/ext4/resize.c | 6 +++++- fs/ext4/super.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 78 insertions(+), 9 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 9012911..c99e44c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1070,7 +1070,9 @@ struct ext4_super_block { __u8 s_last_error_func[32]; /* function where the error happened */ #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts) __u8 s_mount_opts[64]; - __le32 s_reserved[112]; /* Padding to the end of the block */ + __u32 s_reserved1[3]; /* Padding */ + __le32 s_reserved2[108]; /* Padding to the end of the block */ + __le32 s_checksum; /* crc32c(superblock) */ }; #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START) @@ -1906,6 +1908,10 @@ extern int ext4_group_extend(struct super_block *sb, ext4_fsblk_t n_blocks_count); /* super.c */ +extern int ext4_superblock_csum_verify(struct super_block *sb, + struct ext4_super_block *es); +extern void ext4_superblock_csum_set(struct super_block *sb, + struct ext4_super_block *es); extern void *ext4_kvmalloc(size_t size, gfp_t flags); extern void *ext4_kvzalloc(size_t size, gfp_t flags); extern void ext4_kvfree(void *ptr); @@ -2180,6 +2186,9 @@ static inline void ext4_unlock_group(struct super_block *sb, static inline void ext4_mark_super_dirty(struct super_block *sb) { + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + + ext4_superblock_csum_set(sb, es); if (EXT4_SB(sb)->s_journal == NULL) sb->s_dirt =1; } diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index f5240aa..04ddc97 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -136,16 +136,23 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line, } int __ext4_handle_dirty_super(const char *where, unsigned int line, - handle_t *handle, struct super_block *sb) + handle_t *handle, struct super_block *sb, + int now) { struct buffer_head *bh = EXT4_SB(sb)->s_sbh; int err = 0; if (ext4_handle_valid(handle)) { + ext4_superblock_csum_set(sb, + (struct ext4_super_block *)bh->b_data); err = jbd2_journal_dirty_metadata(handle, bh); if (err) ext4_journal_abort_handle(where, line, __func__, bh, handle, err); + } else if (now) { + ext4_superblock_csum_set(sb, + (struct ext4_super_block *)bh->b_data); + mark_buffer_dirty(bh); } else sb->s_dirt = 1; return err; diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index 5802fa1..ed9b78d 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -141,7 +141,8 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line, struct buffer_head *bh); int __ext4_handle_dirty_super(const char *where, unsigned int line, - handle_t *handle, struct super_block *sb); + handle_t *handle, struct super_block *sb, + int now); #define ext4_journal_get_write_access(handle, bh) \ __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh)) @@ -153,8 +154,10 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line, #define ext4_handle_dirty_metadata(handle, inode, bh) \ __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \ (bh)) +#define ext4_handle_dirty_super_now(handle, sb) \ + __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 1) #define ext4_handle_dirty_super(handle, sb) \ - __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb)) + __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 0) handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks); int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 986e238..6e64e0b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3700,8 +3700,7 @@ static int ext4_do_update_inode(handle_t *handle, EXT4_FEATURE_RO_COMPAT_LARGE_FILE); sb->s_dirt = 1; ext4_handle_sync(handle); - err = ext4_handle_dirty_metadata(handle, NULL, - EXT4_SB(sb)->s_sbh); + err = ext4_handle_dirty_super_now(handle, sb); } } raw_inode->i_generation = cpu_to_le32(inode->i_generation); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 50c7294..d0158f2 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2014,7 +2014,7 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) /* Insert this inode at the head of the on-disk orphan list... */ NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); - err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); + err = ext4_handle_dirty_super_now(handle, sb); rc = ext4_mark_iloc_dirty(handle, inode, &iloc); if (!err) err = rc; @@ -2087,7 +2087,7 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) if (err) goto out_brelse; sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); - err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); + err = ext4_handle_dirty_super_now(handle, inode->i_sb); } else { struct ext4_iloc iloc2; struct inode *i_prev = diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 707d3f1..2ad7008 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -511,7 +511,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, ext4_kvfree(o_group_desc); le16_add_cpu(&es->s_reserved_gdt_blocks, -1); - err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); + err = ext4_handle_dirty_super_now(handle, sb); if (err) ext4_std_error(sb, err); @@ -682,6 +682,8 @@ static void update_backups(struct super_block *sb, goto exit_err; } + ext4_superblock_csum_set(sb, (struct ext4_super_block *)data); + while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) { struct buffer_head *bh; @@ -925,6 +927,8 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) /* Update the global fs size fields */ sbi->s_groups_count++; + ext4_superblock_csum_set(sb, + (struct ext4_super_block *)primary->b_data); err = ext4_handle_dirty_metadata(handle, NULL, primary); if (unlikely(err)) { ext4_std_error(sb, err); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f02de28..58157ec 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -120,6 +120,38 @@ static int ext4_verify_csum_type(struct super_block *sb, return es->s_checksum_type == EXT4_CRC32C_CHKSUM; } +static __le32 ext4_superblock_csum(struct super_block *sb, + struct ext4_super_block *es) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + int offset = offsetof(struct ext4_super_block, s_checksum); + __u32 crc; + + crc = ext4_chksum(sbi, ~0, (char *)es, offset); + + return cpu_to_le32(crc); +} + +int ext4_superblock_csum_verify(struct super_block *sb, + struct ext4_super_block *es) +{ + if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return 1; + + return es->s_checksum == ext4_superblock_csum(sb, es); +} + +void ext4_superblock_csum_set(struct super_block *sb, + struct ext4_super_block *es) +{ + if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + return; + + es->s_checksum = ext4_superblock_csum(sb, es); +} + void *ext4_kvmalloc(size_t size, gfp_t flags) { void *ret; @@ -3184,6 +3216,20 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } } + /* Check superblock checksum */ + if (!ext4_superblock_csum_verify(sb, es)) { + ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with " + "invalid superblock checksum. Run e2fsck?"); + silent = 1; + goto cantfind_ext4; + } + + /* Precompute first piece of crc */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) + sbi->s_uuid_crc = ext4_chksum(sbi, ~0, es->s_uuid, + sizeof(es->s_uuid)); + /* Set defaults before we parse the mount options */ def_mount_opts = le32_to_cpu(es->s_default_mount_opts); set_opt(sb, INIT_INODE_TABLE); @@ -4140,6 +4186,7 @@ static int ext4_commit_super(struct super_block *sb, int sync) &EXT4_SB(sb)->s_freeinodes_counter)); sb->s_dirt = 0; BUFFER_TRACE(sbh, "marking dirty"); + ext4_superblock_csum_set(sb, es); mark_buffer_dirty(sbh); if (sync) { error = sync_dirty_buffer(sbh);