fs/ext4/dir.c

File Facts

System

Linux kernel

Corpus path

fs/ext4/dir.c

Extension

.c

Size

18586 bytes

Lines

695

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.
• 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/fs.h
• linux/buffer_head.h
• linux/filelock.h
• linux/slab.h
• linux/iversion.h
• linux/unicode.h
• ext4.h
• xattr.h

Detected Declarations

• struct fname
• function is_dx_dir
• function is_fake_dir_entry
• function __ext4_check_dir_entry
• function ext4_readdir
• function readdir
• function is_32bit_api
• function layer
• function pos2maj_hash
• function pos2min_hash
• function ext4_get_htree_eof
• function ext4_dir_llseek
• function free_rb_tree_fname
• function rbtree_postorder_for_each_entry_safe
• function ext4_htree_init_dir_info
• function ext4_htree_free_dir_info
• function ext4_htree_store_dirent
• function call_filldir
• function ext4_dx_readdir
• function ext4_release_dir
• function ext4_check_all_de
• function ext4_dir_open

Annotated Snippet

const struct file_operations ext4_dir_operations = {
	.open		= ext4_dir_open,
	.llseek		= ext4_dir_llseek,
	.read		= generic_read_dir,
	.iterate_shared	= ext4_readdir,
	.unlocked_ioctl = ext4_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= ext4_compat_ioctl,
#endif
	.fsync		= ext4_sync_file,
	.release	= ext4_release_dir,
	.setlease	= generic_setlease,
};

Annotation

• Immediate include surface: `linux/fs.h`, `linux/buffer_head.h`, `linux/filelock.h`, `linux/slab.h`, `linux/iversion.h`, `linux/unicode.h`, `ext4.h`, `xattr.h`.
• Detected declarations: `struct fname`, `function is_dx_dir`, `function is_fake_dir_entry`, `function __ext4_check_dir_entry`, `function ext4_readdir`, `function readdir`, `function is_32bit_api`, `function layer`, `function pos2maj_hash`, `function pos2min_hash`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: pattern implementation candidate.

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.