From 2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Mon, 24 Aug 2026 01:18:14 +0900 Subject: coccinelle: alloc_cast: drop removed allocators - pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon Signed-off-by: Julia Lawall --- Documentation/filesystems/ext4/bitmaps.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 Documentation/filesystems/ext4/bitmaps.rst (limited to 'Documentation/filesystems/ext4/bitmaps.rst') diff --git a/Documentation/filesystems/ext4/bitmaps.rst b/Documentation/filesystems/ext4/bitmaps.rst new file mode 100644 index 000000000..9d7d7b083 --- /dev/null +++ b/Documentation/filesystems/ext4/bitmaps.rst @@ -0,0 +1,21 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Block and inode Bitmaps +----------------------- + +The data block bitmap tracks the usage of data blocks within the block +group. + +The inode bitmap records which entries in the inode table are in use. + +As with most bitmaps, one bit represents the usage status of one data +block or inode table entry. This implies a block group size of 8 * +number_of_bytes_in_a_logical_block. + +NOTE: If ``BLOCK_UNINIT`` is set for a given block group, various parts +of the kernel and e2fsprogs code pretends that the block bitmap contains +zeros (i.e. all blocks in the group are free). However, it is not +necessarily the case that no blocks are in use -- if ``meta_bg`` is set, +the bitmaps and group descriptor live inside the group. Unfortunately, +ext2fs_test_block_bitmap2() will return '0' for those locations, +which produces confusing debugfs output. -- cgit v1.3.1