From: "Darrick J. Wong" Subject: [PATCH 16/51] e2fsck: Verify block bitmap checksum Date: Sat, 07 Jan 2012 00:34:38 -0800 Message-ID: <20120107083438.25788.38347.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 e8.ny.us.ibm.com ([32.97.182.138]:35520 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759491Ab2AGIeo (ORCPT ); Sat, 7 Jan 2012 03:34:44 -0500 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 7 Jan 2012 03:34:43 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q078Yf7Y307212 for ; Sat, 7 Jan 2012 03:34:41 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q078Yejl008125 for ; Sat, 7 Jan 2012 06:34:41 -0200 In-Reply-To: <20120107083256.25788.41238.stgit@elm3c44.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Check block bitmap checksum and write a new checksum if the verification fails. This is ok because e2fsck has already computed the correct block bitmap. Signed-off-by: Darrick J. Wong --- e2fsck/pass5.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ e2fsck/problem.c | 5 ++++ e2fsck/problem.h | 3 ++ 3 files changed, 73 insertions(+), 0 deletions(-) diff --git a/e2fsck/pass5.c b/e2fsck/pass5.c index fbdde5f..0e86efa 100644 --- a/e2fsck/pass5.c +++ b/e2fsck/pass5.c @@ -28,6 +28,7 @@ static void check_inode_bitmaps(e2fsck_t ctx); static void check_inode_end(e2fsck_t ctx); static void check_block_end(e2fsck_t ctx); static void check_inode_bitmap_checksum(e2fsck_t ctx); +static void check_block_bitmap_checksum(e2fsck_t ctx); void e2fsck_pass5(e2fsck_t ctx) { @@ -66,6 +67,7 @@ void e2fsck_pass5(e2fsck_t ctx) return; check_inode_bitmap_checksum(ctx); + check_block_bitmap_checksum(ctx); ext2fs_free_inode_bitmap(ctx->inode_used_map); ctx->inode_used_map = 0; @@ -138,6 +140,69 @@ static void check_inode_bitmap_checksum(e2fsck_t ctx) ext2fs_free_mem(&buf); } +static void check_block_bitmap_checksum(e2fsck_t ctx) +{ + struct problem_context pctx; + struct ext4_group_desc *gdp; + char *buf; + dgrp_t i; + int nbytes; + blk64_t blk_itr; + errcode_t retval; + int csum_flag = 0; + + /* If bitmap is dirty from being fixed, checksum will be corrected */ + if (ext2fs_test_bb_dirty(ctx->fs)) + return; + + nbytes = (size_t)(EXT2_BLOCKS_PER_GROUP(ctx->fs->super) / 8); + retval = ext2fs_get_memalign(ctx->fs->blocksize, ctx->fs->blocksize, + &buf); + if (retval) { + com_err(ctx->program_name, 0, + _("check_block_bitmap_checksum: Memory allocation error")); + fatal_error(ctx, 0); + } + + if (EXT2_HAS_RO_COMPAT_FEATURE(ctx->fs->super, + EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + csum_flag = 1; + + clear_problem_context(&pctx); + for (i = 0; i < ctx->fs->group_desc_count; i++) { + if (csum_flag && ext2fs_bg_flags_test(ctx->fs, i, + EXT2_BG_BLOCK_UNINIT)) + continue; + + blk_itr = EXT2FS_B2C(ctx->fs, + ctx->fs->super->s_first_data_block) + + (i * (nbytes << 3)); + gdp = (struct ext4_group_desc *)ext2fs_group_desc(ctx->fs, + ctx->fs->group_desc, i); + retval = ext2fs_get_block_bitmap_range2(ctx->fs->block_map, + blk_itr, nbytes << 3, + buf); + if (retval) + break; + + if (ext2fs_block_bitmap_csum_verify(ctx->fs, i, buf, nbytes)) + continue; + pctx.group = i; + if (!fix_problem(ctx, PR_5_BLOCK_BITMAP_CSUM_INVALID, &pctx)) + continue; + + /* + * Fixing one checksum will rewrite all of them. The bitmap + * will be checked against the one we made during pass1 for + * discrepancies, and fixed if need be. + */ + ext2fs_mark_bb_dirty(ctx->fs); + break; + } + + ext2fs_free_mem(&buf); +} + static void e2fsck_discard_blocks(e2fsck_t ctx, io_manager manager, blk64_t start, blk64_t count) { diff --git a/e2fsck/problem.c b/e2fsck/problem.c index 54894d5..95813ce 100644 --- a/e2fsck/problem.c +++ b/e2fsck/problem.c @@ -1694,6 +1694,11 @@ static struct e2fsck_problem problem_table[] = { N_("@g %g @i bitmap does not match checksum\n"), PROMPT_FIX, PR_LATCH_IBITMAP | PR_PREEN_OK }, + /* Group N block bitmap does not match checksum */ + { PR_5_BLOCK_BITMAP_CSUM_INVALID, + N_("@g %g @b bitmap does not match checksum\n"), + PROMPT_FIX, PR_LATCH_BBITMAP | PR_PREEN_OK }, + /* Post-Pass 5 errors */ /* Recreate journal if E2F_FLAG_JOURNAL_INODE flag is set */ diff --git a/e2fsck/problem.h b/e2fsck/problem.h index dbc256e..51a911b 100644 --- a/e2fsck/problem.h +++ b/e2fsck/problem.h @@ -1022,6 +1022,9 @@ struct problem_context { /* Inode bitmap checksum does not match */ #define PR_5_INODE_BITMAP_CSUM_INVALID 0x05001A +/* Block bitmap checksum does not match */ +#define PR_5_BLOCK_BITMAP_CSUM_INVALID 0x05001B + /* * Post-Pass 5 errors */