fs/squashfs/file.c

File Facts

System

Linux kernel

Corpus path

fs/squashfs/file.c

Extension

.c

Size

21075 bytes

Lines

782

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/fs.h
• linux/filelock.h
• linux/vfs.h
• linux/kernel.h
• linux/slab.h
• linux/string.h
• linux/pagemap.h
• linux/mutex.h
• squashfs_fs.h
• squashfs_fs_sb.h
• squashfs_fs_i.h
• squashfs.h
• page_actor.h

Detected Declarations

• function Copyright
• function release_meta_index
• function read_indexes
• function cache
• function fill_meta_index
• function read_blocklist_ptrs
• function fill_meta_index
• function read_blocklist
• function squashfs_fill_page
• function squashfs_copy_cache
• function squashfs_readpage_fragment
• function squashfs_readpage_sparse
• function squashfs_read_folio
• function squashfs_readahead_fragment
• function squashfs_readahead
• function seek_hole_data
• function squashfs_i
• function squashfs_llseek

Annotated Snippet

const struct file_operations squashfs_file_operations = {
	.llseek		= squashfs_llseek,
	.read_iter	= generic_file_read_iter,
	.mmap_prepare	= generic_file_readonly_mmap_prepare,
	.splice_read	= filemap_splice_read,
	.setlease	= generic_setlease,
};

Annotation

• Immediate include surface: `linux/fs.h`, `linux/filelock.h`, `linux/vfs.h`, `linux/kernel.h`, `linux/slab.h`, `linux/string.h`, `linux/pagemap.h`, `linux/mutex.h`.
• Detected declarations: `function Copyright`, `function release_meta_index`, `function read_indexes`, `function cache`, `function fill_meta_index`, `function read_blocklist_ptrs`, `function fill_meta_index`, `function read_blocklist`, `function squashfs_fill_page`, `function squashfs_copy_cache`.
• 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.