drivers/md/dm-thin.c

File Facts

System

Linux kernel

Corpus path

drivers/md/dm-thin.c

Extension

.c

Size

115500 bytes

Lines

4559

Domain

Driver Families

Bucket

drivers/md

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• dm-thin-metadata.h
• dm-bio-prison-v1.h
• dm.h
• linux/device-mapper.h
• linux/dm-io.h
• linux/dm-kcopyd.h
• linux/jiffies.h
• linux/log2.h
• linux/list.h
• linux/rculist.h
• linux/init.h
• linux/module.h
• linux/slab.h
• linux/vmalloc.h
• linux/sort.h
• linux/rbtree.h

Detected Declarations

• struct throttle
• struct dm_thin_new_mapping
• struct pool_features
• struct thin_c
• struct pool
• struct pool_c
• struct thin_c
• struct discard_op
• struct dm_thin_endio_hook
• struct dm_thin_new_mapping
• struct remap_info
• struct pool_work
• struct noflush_work
• enum lock_space
• enum pool_mode
• function build_key
• function build_data_key
• function build_virtual_key
• function throttle_init
• function throttle_work_start
• function throttle_work_update
• function throttle_work_complete
• function throttle_lock
• function throttle_unlock
• function get_pool_mode
• function notify_of_pool_mode_change
• function block_size_is_power_of_two
• function block_to_sectors
• function begin_discard
• function issue_discard
• function end_discard
• function wake_worker
• function bio_detain
• function cell_release
• function cell_visit_release
• function cell_release_no_holder
• function cell_error_with_code
• function get_pool_io_error_code
• function cell_error
• function cell_success
• function cell_requeue
• function pool_table_init
• function pool_table_exit
• function __pool_table_insert
• function __pool_table_remove
• function list_for_each_entry
• function list_for_each_entry
• function error_bio_list

Annotated Snippet

module_init(dm_thin_init);
module_exit(dm_thin_exit);

module_param_named(no_space_timeout, no_space_timeout_secs, uint, 0644);
MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");

MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
MODULE_AUTHOR("Joe Thornber <dm-devel@lists.linux.dev>");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `dm-thin-metadata.h`, `dm-bio-prison-v1.h`, `dm.h`, `linux/device-mapper.h`, `linux/dm-io.h`, `linux/dm-kcopyd.h`, `linux/jiffies.h`, `linux/log2.h`.
• Detected declarations: `struct throttle`, `struct dm_thin_new_mapping`, `struct pool_features`, `struct thin_c`, `struct pool`, `struct pool_c`, `struct thin_c`, `struct discard_op`, `struct dm_thin_endio_hook`, `struct dm_thin_new_mapping`.
• Atlas domain: Driver Families / drivers/md.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

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.