From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:26120 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750943AbdDHDD7 (ORCPT ); Fri, 7 Apr 2017 23:03:59 -0400 Subject: [PATCH 2/4] xfs_db: use iocursor type to guess btree geometry if bad magic From: "Darrick J. Wong" Date: Fri, 07 Apr 2017 20:03:55 -0700 Message-ID: <149162063502.22901.11947139521251833946.stgit@birch.djwong.org> In-Reply-To: <149162062276.22901.7801103937404880951.stgit@birch.djwong.org> References: <149162062276.22901.7801103937404880951.stgit@birch.djwong.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: sandeen@redhat.com, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org From: Darrick J. Wong The function block_to_bt plays an integral role in determining the btree geometry of a block that we want to manipulate with the debugger. Normally we use the block magic to find the geometry profile, but if the magic is bad we'll never find it and return NULL. The callers of this function do not check for NULL and crash. Therefore, if we can't find a geometry profile matching the magic number, use the iocursor type to guess the profile and scowl about that to stdout. This makes it so that even with a corrupt magic we can try to print the fields instead of crashing the debugger. Signed-off-by: Darrick J. Wong --- db/btblock.c | 51 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 8 deletions(-) diff --git a/db/btblock.c b/db/btblock.c index 835a5f0..ba81645 100644 --- a/db/btblock.c +++ b/db/btblock.c @@ -25,6 +25,8 @@ #include "print.h" #include "bit.h" #include "init.h" +#include "io.h" +#include "output.h" /* * Definition of the possible btree block layouts. @@ -122,13 +124,49 @@ static struct xfs_db_btree * block_to_bt( struct xfs_btree_block *bb) { - struct xfs_db_btree *btp = &btrees[0]; + struct xfs_db_btree *btp; + uint32_t magic; + + magic = be32_to_cpu((bb)->bb_magic); + for (btp = &btrees[0]; btp->magic != 0; btp++) + if (magic == btp->magic) + return btp; - do { - if (be32_to_cpu((bb)->bb_magic) == btp->magic) +#define M(a,b) (!xfs_sb_version_hascrc(&mp->m_sb) ? (a) : (b)) + switch (iocur_top->typ->typnm) { + case TYP_BMAPBTA: + case TYP_BMAPBTD: + magic = M(XFS_BMAP_MAGIC, XFS_BMAP_CRC_MAGIC); + break; + case TYP_BNOBT: + magic = M(XFS_ABTB_MAGIC, XFS_ABTB_CRC_MAGIC); + break; + case TYP_CNTBT: + magic = M(XFS_ABTC_MAGIC, XFS_ABTC_CRC_MAGIC); + break; + case TYP_INOBT: + magic = M(XFS_IBT_MAGIC, XFS_IBT_CRC_MAGIC); + break; + case TYP_FINOBT: + magic = M(XFS_FIBT_MAGIC, XFS_FIBT_CRC_MAGIC); + break; + case TYP_RMAPBT: + magic = M(0, XFS_RMAP_CRC_MAGIC); + break; + case TYP_REFCBT: + magic = M(0, XFS_REFC_CRC_MAGIC); + break; + default: + ASSERT(0); + } +#undef M + dbprintf(_("Bad btree magic 0x%x; coercing to %s.\n"), + be32_to_cpu((bb)->bb_magic), + iocur_top->typ->name); + + for (btp = &btrees[0]; btp->magic != 0; btp++) + if (magic == btp->magic) return btp; - btp++; - } while (btp->magic != 0); return NULL; } @@ -193,7 +231,6 @@ btblock_key_offset( int offset; ASSERT(startoff == 0); - ASSERT(block->bb_level != 0); offset = bt->block_len + (idx - 1) * bt->key_len; return bitize(offset); @@ -214,7 +251,6 @@ btblock_ptr_offset( int maxrecs; ASSERT(startoff == 0); - ASSERT(block->bb_level != 0); maxrecs = btblock_maxrecs(bt, mp->m_sb.sb_blocksize); offset = bt->block_len + @@ -238,7 +274,6 @@ btblock_rec_offset( int offset; ASSERT(startoff == 0); - ASSERT(block->bb_level == 0); offset = bt->block_len + (idx - 1) * bt->rec_len; return bitize(offset);