kernel/relay.c

File Facts

System

Linux kernel

Corpus path

kernel/relay.c

Extension

.c

Size

24497 bytes

Lines

1013

Domain

Core OS

Bucket

Scheduler, Processes, Timers, Sync, And Syscalls

Inferred role

Core OS: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• 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

• linux/errno.h
• linux/stddef.h
• linux/slab.h
• linux/export.h
• linux/string.h
• linux/relay.h
• linux/vmalloc.h
• linux/mm.h
• linux/cpu.h
• linux/splice.h

Detected Declarations

• struct rchan_percpu_buf_dispatcher
• function fault
• function relay_free_page_array
• function relay_mmap_prepare_buf
• function kref_put
• function relay_destroy_buf
• function kref_put
• function relay_buf_empty
• function relay_buf_full
• function relay_subbuf_start
• function wakeup_readers
• function relay_reset
• function relay_reset
• function relay_set_buf_dentry
• function relay_open
• function relay_close_buf
• function relay_prepare_cpu
• function relay_switch_subbuf
• function relay_subbufs_consumed
• function relay_close
• function relay_flush
• function relay_stats
• function for_each_online_cpu
• function relay_file_open
• function relay_mmap_prepare_buf
• function relay_file_poll
• function relay_file_release
• function relay_file_read_consume
• function relay_file_read_avail
• function relay_file_read_subbuf_avail
• function relay_file_read_start_pos
• function relay_file_read_end_pos
• function relay_file_read
• export relay_buf_full
• export relay_reset
• export relay_open
• export relay_switch_subbuf
• export relay_subbufs_consumed
• export relay_close
• export relay_flush
• export relay_file_operations

Annotated Snippet

const struct file_operations relay_file_operations = {
	.open		= relay_file_open,
	.poll		= relay_file_poll,
	.mmap_prepare	= relay_file_mmap_prepare,
	.read		= relay_file_read,
	.release	= relay_file_release,
};
EXPORT_SYMBOL_GPL(relay_file_operations);

Annotation

• Immediate include surface: `linux/errno.h`, `linux/stddef.h`, `linux/slab.h`, `linux/export.h`, `linux/string.h`, `linux/relay.h`, `linux/vmalloc.h`, `linux/mm.h`.
• Detected declarations: `struct rchan_percpu_buf_dispatcher`, `function fault`, `function relay_free_page_array`, `function relay_mmap_prepare_buf`, `function kref_put`, `function relay_destroy_buf`, `function kref_put`, `function relay_buf_empty`, `function relay_buf_full`, `function relay_subbuf_start`.
• Atlas domain: Core OS / Scheduler, Processes, Timers, Sync, And Syscalls.
• Implementation status: pattern implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• 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.