fs/gfs2/file.c

File Facts

System

Linux kernel

Corpus path

fs/gfs2/file.c

Extension

.c

Size

41739 bytes

Lines

1643

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.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• 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/slab.h
• linux/spinlock.h
• linux/compat.h
• linux/completion.h
• linux/buffer_head.h
• linux/pagemap.h
• linux/uio.h
• linux/blkdev.h
• linux/mm.h
• linux/mount.h
• linux/fs.h
• linux/filelock.h
• linux/gfs2_ondisk.h
• linux/falloc.h
• linux/swap.h
• linux/crc32.h
• linux/writeback.h
• linux/uaccess.h
• linux/dlm.h
• linux/dlm_plock.h
• linux/delay.h
• linux/backing-dev.h
• linux/fileattr.h
• gfs2.h
• incore.h
• bmap.h
• aops.h
• dir.h
• glock.h
• glops.h
• inode.h
• log.h

Detected Declarations

• function Copyright
• function gfs2_readdir
• function gfs2_gfsflags_to_fsflags
• function gfs2_fileattr_get
• function gfs2_set_inode_flags
• function do_gfs2_set_flags
• function gfs2_fileattr_set
• function gfs2_getlabel
• function gfs2_ioctl
• function gfs2_compat_ioctl
• function gfs2_size_hint
• function gfs2_allocate_folio_backing
• function gfs2_page_mkwrite
• function gfs2_fault
• function update
• function gfs2_open_common
• function gfs2_open
• function gfs2_release
• function gfs2_fsync
• function should_fault_in_pages
• function gfs2_file_direct_read
• function gfs2_file_direct_write
• function gfs2_file_read_iter
• function gfs2_file_buffered_write
• function gfs2_file_write_iter
• function fallocate_chunk
• function calc_max_reserv
• function __gfs2_fallocate
• function gfs2_fallocate
• function gfs2_file_splice_write
• function gfs2_lock
• function __flock_holder_uninit
• function do_flock
• function do_unflock
• function gfs2_flock

Annotated Snippet

const struct file_operations gfs2_file_fops = {
	.llseek		= gfs2_llseek,
	.read_iter	= gfs2_file_read_iter,
	.write_iter	= gfs2_file_write_iter,
	.iopoll		= iocb_bio_iopoll,
	.unlocked_ioctl	= gfs2_ioctl,
	.compat_ioctl	= gfs2_compat_ioctl,
	.mmap		= gfs2_mmap,
	.open		= gfs2_open,
	.release	= gfs2_release,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.flock		= gfs2_flock,
	.splice_read	= copy_splice_read,
	.splice_write	= gfs2_file_splice_write,
	.fallocate	= gfs2_fallocate,
	.fop_flags	= FOP_ASYNC_LOCK,
};

const struct file_operations gfs2_dir_fops = {
	.iterate_shared	= gfs2_readdir,
	.unlocked_ioctl	= gfs2_ioctl,
	.compat_ioctl	= gfs2_compat_ioctl,
	.open		= gfs2_open,
	.release	= gfs2_release,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.flock		= gfs2_flock,
	.llseek		= default_llseek,
	.fop_flags	= FOP_ASYNC_LOCK,
};

#endif /* CONFIG_GFS2_FS_LOCKING_DLM */

const struct file_operations gfs2_file_fops_nolock = {
	.llseek		= gfs2_llseek,
	.read_iter	= gfs2_file_read_iter,
	.write_iter	= gfs2_file_write_iter,
	.iopoll		= iocb_bio_iopoll,
	.unlocked_ioctl	= gfs2_ioctl,
	.compat_ioctl	= gfs2_compat_ioctl,
	.mmap		= gfs2_mmap,
	.open		= gfs2_open,
	.release	= gfs2_release,
	.fsync		= gfs2_fsync,
	.splice_read	= copy_splice_read,
	.splice_write	= gfs2_file_splice_write,
	.setlease	= generic_setlease,
	.fallocate	= gfs2_fallocate,
};

const struct file_operations gfs2_dir_fops_nolock = {
	.iterate_shared	= gfs2_readdir,
	.unlocked_ioctl	= gfs2_ioctl,
	.compat_ioctl	= gfs2_compat_ioctl,
	.open		= gfs2_open,
	.release	= gfs2_release,
	.fsync		= gfs2_fsync,
	.llseek		= default_llseek,
	.setlease	= generic_setlease,
};

Annotation

• Immediate include surface: `linux/slab.h`, `linux/spinlock.h`, `linux/compat.h`, `linux/completion.h`, `linux/buffer_head.h`, `linux/pagemap.h`, `linux/uio.h`, `linux/blkdev.h`.
• Detected declarations: `function Copyright`, `function gfs2_readdir`, `function gfs2_gfsflags_to_fsflags`, `function gfs2_fileattr_get`, `function gfs2_set_inode_flags`, `function do_gfs2_set_flags`, `function gfs2_fileattr_set`, `function gfs2_getlabel`, `function gfs2_ioctl`, `function gfs2_compat_ioctl`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: pattern implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• 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.