drivers/block/xen-blkback/blkback.c

File Facts

System

Linux kernel

Corpus path

drivers/block/xen-blkback/blkback.c

Extension

.c

Size

45168 bytes

Lines

1568

Domain

Driver Families

Bucket

drivers/block

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.
• Touches IRQ or DMA behavior; this matters for the representative real-device path.
• 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/spinlock.h
• linux/kthread.h
• linux/list.h
• linux/delay.h
• linux/freezer.h
• linux/bitmap.h
• xen/events.h
• xen/page.h
• xen/xen.h
• asm/xen/hypervisor.h
• asm/xen/hypercall.h
• xen/balloon.h
• xen/grant_table.h
• common.h

Detected Declarations

• function persistent_gnt_timeout
• function context
• function put_persistent_gnt
• function free_persistent_gnts
• function foreach_grant_safe
• function xen_blkbk_unmap_purged_grants
• function purge_persistent_gnt
• function free_req
• function devices
• function xen_vbd_resize
• function blkif_notify_work
• function xen_blkif_be_int
• function print_stats
• function xen_blkif_schedule
• function xen_blkbk_free_caches
• function xen_blkbk_unmap_prepare
• function xen_blkbk_unmap_and_respond_callback
• function drain_complete
• function xen_blkbk_unmap_and_respond
• function xen_blkbk_unmap
• function xen_blkbk_map
• function xen_blkbk_map_seg
• function xen_blkbk_parse_indirect
• function dispatch_discard_io
• function dispatch_other_io
• function xen_blk_drain_io
• function __end_block_io_op
• function end_block_io_op
• function blkif_get_x86_32_req
• function blkif_get_x86_64_req
• function __do_block_io_op
• function do_block_io_op
• function dispatch_rw_block_io
• function make_response
• function xen_blkif_init
• function xen_blkif_fini
• module init xen_blkif_init

Annotated Snippet

module_init(xen_blkif_init);

static void __exit xen_blkif_fini(void)
{
	xen_blkif_xenbus_fini();
	xen_blkif_interface_fini();
}

module_exit(xen_blkif_fini);

MODULE_DESCRIPTION("Virtual block device back-end driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("xen-backend:vbd");

Annotation

• Immediate include surface: `linux/spinlock.h`, `linux/kthread.h`, `linux/list.h`, `linux/delay.h`, `linux/freezer.h`, `linux/bitmap.h`, `xen/events.h`, `xen/page.h`.
• Detected declarations: `function persistent_gnt_timeout`, `function context`, `function put_persistent_gnt`, `function free_persistent_gnts`, `function foreach_grant_safe`, `function xen_blkbk_unmap_purged_grants`, `function purge_persistent_gnt`, `function free_req`, `function devices`, `function xen_vbd_resize`.
• Atlas domain: Driver Families / drivers/block.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
• IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.

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.