drivers/md/dm-ps-queue-length.c

File Facts

System

Linux kernel

Corpus path

drivers/md/dm-ps-queue-length.c

Extension

.c

Size

6104 bytes

Lines

287

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.h
• dm-path-selector.h
• linux/slab.h
• linux/ctype.h
• linux/errno.h
• linux/module.h
• linux/atomic.h

Detected Declarations

• struct selector
• struct path_info
• function ql_create
• function ql_free_paths
• function list_for_each_entry_safe
• function ql_destroy
• function ql_status
• function ql_add_path
• function ql_fail_path
• function ql_reinstate_path
• function list_for_each_entry
• function ql_start_io
• function ql_end_io
• function dm_ql_init
• function dm_ql_exit
• module init dm_ql_init

Annotated Snippet

module_init(dm_ql_init);
module_exit(dm_ql_exit);

MODULE_AUTHOR("Stefan Bader <Stefan.Bader at de.ibm.com>");
MODULE_DESCRIPTION(
	"(C) Copyright IBM Corp. 2004,2005   All Rights Reserved.\n"
	DM_NAME " path selector to balance the number of in-flight I/Os"
);
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `dm.h`, `dm-path-selector.h`, `linux/slab.h`, `linux/ctype.h`, `linux/errno.h`, `linux/module.h`, `linux/atomic.h`.
• Detected declarations: `struct selector`, `struct path_info`, `function ql_create`, `function ql_free_paths`, `function list_for_each_entry_safe`, `function ql_destroy`, `function ql_status`, `function ql_add_path`, `function ql_fail_path`, `function ql_reinstate_path`.
• 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.