Documentation/filesystems/ext4/blockmap.rst
Source file repositories/reference/linux-study-clean/Documentation/filesystems/ext4/blockmap.rst
File Facts
- System
- Linux kernel
- Corpus path
Documentation/filesystems/ext4/blockmap.rst- Extension
.rst- Size
- 11646 bytes
- Lines
- 50
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
.. SPDX-License-Identifier: GPL-2.0
+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| i.i_block Offset | Where It Points |
+=====================+==============================================================================================================================================================================================================================+
| 0 to 11 | Direct map to file blocks 0 to 11. |
+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 12 | Indirect block: (file blocks 12 to (``$block_size`` / 4) + 11, or 12 to 1035 if 4KiB blocks) |
| | |
| | +------------------------------+--------------------------------------------------------------------+ |
| | | Indirect Block Offset | Where It Points | |
| | +==============================+====================================================================+ |
| | | 0 to (``$block_size`` / 4) | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks) | |
| | +------------------------------+--------------------------------------------------------------------+ |
+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 13 | Double-indirect block: (file blocks ``$block_size``/4 + 12 to (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 11, or 1036 to 1049611 if 4KiB blocks) |
| | |
| | +--------------------------------+---------------------------------------------------------------------------------------------------------+ |
| | | Double Indirect Block Offset | Where It Points | |
| | +================================+=========================================================================================================+ |
| | | 0 to (``$block_size`` / 4) | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks) | |
| | | | | |
| | | | +------------------------------+--------------------------------------------------------------------+ | |
| | | | | Indirect Block Offset | Where It Points | | |
| | | | +==============================+====================================================================+ | |
| | | | | 0 to (``$block_size`` / 4) | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks) | | |
| | | | +------------------------------+--------------------------------------------------------------------+ | |
| | +--------------------------------+---------------------------------------------------------------------------------------------------------+ |
+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 14 | Triple-indirect block: (file blocks (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 12 to (``$block_size`` / 4) ^ 3 + (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 12, or 1049612 to 1074791436 if 4KiB blocks) |
| | |
| | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+ |
| | | Triple Indirect Block Offset | Where It Points | |
| | +================================+================================================================================================================================================+ |
| | | 0 to (``$block_size`` / 4) | Map to (``$block_size`` / 4) double indirect blocks (1024 if 4KiB blocks) | |
| | | | | |
| | | | +--------------------------------+---------------------------------------------------------------------------------------------------------+ | |
| | | | | Double Indirect Block Offset | Where It Points | | |
| | | | +================================+=========================================================================================================+ | |
| | | | | 0 to (``$block_size`` / 4) | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks) | | |
| | | | | | | | |
| | | | | | +------------------------------+--------------------------------------------------------------------+ | | |
| | | | | | | Indirect Block Offset | Where It Points | | | |
| | | | | | +==============================+====================================================================+ | | |
| | | | | | | 0 to (``$block_size`` / 4) | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks) | | | |
| | | | | | +------------------------------+--------------------------------------------------------------------+ | | |
| | | | +--------------------------------+---------------------------------------------------------------------------------------------------------+ | |
| | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+ |
+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.