fs/erofs/data.c

File Facts

System

Linux kernel

Corpus path

fs/erofs/data.c

Extension

.c

Size

14437 bytes

Lines

536

Domain

Core OS

Bucket

VFS And Filesystem Core

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.
• 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

• internal.h
• linux/filelock.h
• linux/sched/mm.h
• trace/events/erofs.h

Detected Declarations

• struct erofs_iomap_iter_ctx
• function Copyright
• function erofs_put_metabuf
• function inodes
• function erofs_init_metabuf
• function erofs_map_blocks
• function erofs_fill_from_devinfo
• function erofs_map_dev
• function idr_for_each_entry
• function erofs_onlinefolio_init
• function erofs_onlinefolio_split
• function erofs_onlinefolio_end
• function erofs_iomap_begin
• function erofs_iomap_end
• function erofs_fiemap
• function erofs_read_folio
• function erofs_readahead
• function erofs_bmap
• function erofs_file_read_iter
• function erofs_dax_huge_fault
• function erofs_dax_fault
• function erofs_file_mmap_prepare
• function erofs_file_llseek

Annotated Snippet

const struct file_operations erofs_file_fops = {
	.llseek		= erofs_file_llseek,
	.read_iter	= erofs_file_read_iter,
	.unlocked_ioctl = erofs_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = erofs_compat_ioctl,
#endif
	.mmap_prepare	= erofs_file_mmap_prepare,
	.get_unmapped_area = thp_get_unmapped_area,
	.splice_read	= filemap_splice_read,
	.setlease	= generic_setlease,
};

Annotation

• Immediate include surface: `internal.h`, `linux/filelock.h`, `linux/sched/mm.h`, `trace/events/erofs.h`.
• Detected declarations: `struct erofs_iomap_iter_ctx`, `function Copyright`, `function erofs_put_metabuf`, `function inodes`, `function erofs_init_metabuf`, `function erofs_map_blocks`, `function erofs_fill_from_devinfo`, `function erofs_map_dev`, `function idr_for_each_entry`, `function erofs_onlinefolio_init`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: pattern 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.