fs/affs/file.c

File Facts

System

Linux kernel

Corpus path

fs/affs/file.c

Extension

.c

Size

26393 bytes

Lines

1021

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

• linux/uio.h
• linux/blkdev.h
• linux/filelock.h
• linux/mpage.h
• affs.h

Detected Declarations

• function affs_file_open
• function affs_file_release
• function affs_grow_extcache
• function affs_alloc_extblock
• function affs_get_extblock
• function affs_get_extblock_slow
• function affs_get_block
• function affs_writepages
• function affs_read_folio
• function affs_write_failed
• function affs_direct_IO
• function affs_write_begin
• function affs_write_end
• function _affs_bmap
• function affs_bread_ino
• function affs_getzeroblk_ino
• function affs_getemptyblk_ino
• function affs_do_read_folio_ofs
• function affs_extent_file_ofs
• function affs_read_folio_ofs
• function affs_write_begin_ofs
• function affs_write_end_ofs
• function affs_free_prealloc
• function affs_truncate
• function affs_file_fsync

Annotated Snippet

const struct file_operations affs_file_operations = {
	.llseek		= generic_file_llseek,
	.read_iter	= generic_file_read_iter,
	.write_iter	= generic_file_write_iter,
	.mmap_prepare	= generic_file_mmap_prepare,
	.open		= affs_file_open,
	.release	= affs_file_release,
	.fsync		= affs_file_fsync,
	.splice_read	= filemap_splice_read,
	.setlease	= generic_setlease,
};

const struct inode_operations affs_file_inode_operations = {
	.setattr	= affs_setattr,
};

Annotation

• Immediate include surface: `linux/uio.h`, `linux/blkdev.h`, `linux/filelock.h`, `linux/mpage.h`, `affs.h`.
• Detected declarations: `function affs_file_open`, `function affs_file_release`, `function affs_grow_extcache`, `function affs_alloc_extblock`, `function affs_get_extblock`, `function affs_get_extblock_slow`, `function affs_get_block`, `function affs_writepages`, `function affs_read_folio`, `function affs_write_failed`.
• 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.