Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 55 insertions, 0 deletions

diff --git a/Documentation/filesystems/ext4/special_inodes.rst b/Documentation/filesystems/ext4/special_inodes.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+Special inodes
+--------------
+
+ext4 reserves some inode for special features, as follows:
+
+.. list-table::
+   :widths: 6 70
+   :header-rows: 1
+
+   * - inode Number
+     - Purpose
+   * - 0
+     - Doesn't exist; there is no inode 0.
+   * - 1
+     - List of defective blocks.
+   * - 2
+     - Root directory.
+   * - 3
+     - User quota.
+   * - 4
+     - Group quota.
+   * - 5
+     - Boot loader.
+   * - 6
+     - Undelete directory.
+   * - 7
+     - Reserved group descriptors inode. (“resize inode”)
+   * - 8
+     - Journal inode.
+   * - 9
+     - The “exclude” inode, for snapshots(?)
+   * - 10
+     - Replica inode, used for some non-upstream feature?
+   * - 11
+     - Traditional first non-reserved inode. Usually this is the lost+found directory. See s_first_ino in the superblock.
+
+Note that there are also some inodes allocated from non-reserved inode numbers
+for other filesystem features which are not referenced from standard directory
+hierarchy. These are generally reference from the superblock. They are:
+
+.. list-table::
+   :widths: 20 50
+   :header-rows: 1
+
+   * - Superblock field
+     - Description
+
+   * - s_lpf_ino
+     - Inode number of lost+found directory.
+   * - s_prj_quota_inum
+     - Inode number of quota file tracking project quotas
+   * - s_orphan_file_inum
+     - Inode number of file tracking orphan inodes.