design: merge both metadata integrity chapters
We don't need to have two chapters on metadata integrity, so merge them.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
diff --git a/design/XFS_Filesystem_Structure/metadata_integrity.asciidoc b/design/XFS_Filesystem_Structure/metadata_integrity.asciidoc
deleted file mode 100644
index f948d5e..0000000
--- a/design/XFS_Filesystem_Structure/metadata_integrity.asciidoc
+++ /dev/null
@@ -1,36 +0,0 @@
-= Metadata Integrity
-
-Prior to version 5, most XFS metadata blocks contained a magic number that
-could provide a minimal sanity check that a block read off the disk contained
-the same type of data that the code thought it was reading off the disk.
-However, this was insufficient -- given a correct type code, it was still
-impossible to tell if the block was from a previous filesystem, or happened to
-be owned by something else, or had been written to the wrong location on disk.
-Furthermore, not all metadata blocks had magic numbers -- remote extended
-attributes and extent symbolic links had no protection at all.
-
-Therefore, the version 5 disk format introduced larger headers for all metadata
-types, which enable the filesystem to check information being read from the
-disk more rigorously. Metadata integrity fields now include:
-
-* *Magic* numbers, to classify all types of metadata. This is unchanged from v4.
-* A copy of the filesystem *UUID*, to confirm that a given disk block is connected to the superblock.
-* The *owner*, to avoid accessing a piece of metadata which belongs to some other part of the filesystem.
-* The filesystem *block number*, to detect misplaced writes.
-* The *log serial number* of the last write to this block, to avoid replaying obsolete log entries.
-* A CRC32c *checksum* of the entire block, to detect minor corruption.
-
-Metadata integrity coverage has been extended to all metadata blocks in the
-filesystem, with the following notes:
-
-* Inodes can have multiple ``owners'' in the directory tree; therefore the record contains the inode number instead of an owner or a block number.
-* Superblocks have no owners.
-* The disk quota file has no owner or block numbers.
-* Metadata owned by files list the inode number as the owner.
-* Per-AG data and B+tree blocks list the AG number as the owner.
-* Per-AG header sectors don't list owners or block numbers, since they have fixed locations.
-* Remote attribute blocks are not logged and therefore the LSN must be -1.
-
-This functionality enables XFS to decide that a block contents are so
-unexpected that it should stop immediately. Unfortunately checksums do not
-allow for automatic correction. Please keep regular backups, as always.
diff --git a/design/XFS_Filesystem_Structure/self_describing_metadata.asciidoc b/design/XFS_Filesystem_Structure/self_describing_metadata.asciidoc
index c3038b9..c79e865 100644
--- a/design/XFS_Filesystem_Structure/self_describing_metadata.asciidoc
+++ b/design/XFS_Filesystem_Structure/self_describing_metadata.asciidoc
@@ -1,4 +1,4 @@
-= XFS Self Describing Metadata
+= Metadata Integrity
== Introduction
@@ -30,6 +30,31 @@
concern for supporting PB scale filesystems is minimising the time and effort
required for basic forensic analysis of the filesystem structure.
+Therefore, the version 5 disk format introduced larger headers for all metadata
+types, which enable the filesystem to check information being read from the
+disk more rigorously. Metadata integrity fields now include:
+
+* *Magic* numbers, to classify all types of metadata. This is unchanged from v4.
+* A copy of the filesystem *UUID*, to confirm that a given disk block is connected to the superblock.
+* The *owner*, to avoid accessing a piece of metadata which belongs to some other part of the filesystem.
+* The filesystem *block number*, to detect misplaced writes.
+* The *log serial number* of the last write to this block, to avoid replaying obsolete log entries.
+* A CRC32c *checksum* of the entire block, to detect minor corruption.
+
+Metadata integrity coverage has been extended to all metadata blocks in the
+filesystem, with the following notes:
+
+* Inodes can have multiple ``owners'' in the directory tree; therefore the record contains the inode number instead of an owner or a block number.
+* Superblocks have no owners.
+* The disk quota file has no owner or block numbers.
+* Metadata owned by files list the inode number as the owner.
+* Per-AG data and B+tree blocks list the AG number as the owner.
+* Per-AG header sectors don't list owners or block numbers, since they have fixed locations.
+* Remote attribute blocks are not logged and therefore the LSN must be -1.
+
+This functionality enables XFS to decide that a block contents are so
+unexpected that it should stop immediately. Unfortunately checksums do not
+allow for automatic correction. Please keep regular backups, as always.
== Self Describing Metadata
diff --git a/design/XFS_Filesystem_Structure/xfs_filesystem_structure.asciidoc b/design/XFS_Filesystem_Structure/xfs_filesystem_structure.asciidoc
index 15ab185..5c1642c 100644
--- a/design/XFS_Filesystem_Structure/xfs_filesystem_structure.asciidoc
+++ b/design/XFS_Filesystem_Structure/xfs_filesystem_structure.asciidoc
@@ -46,8 +46,6 @@
include::overview.asciidoc[]
-include::metadata_integrity.asciidoc[]
-
include::self_describing_metadata.asciidoc[]
include::delayed_logging.asciidoc[]
