fs/udf/file.c

File Facts

System

Linux kernel

Corpus path

fs/udf/file.c

Extension

.c

Size

6852 bytes

Lines

262

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

• udfdecl.h
• linux/fs.h
• linux/uaccess.h
• linux/kernel.h
• linux/string.h
• linux/capability.h
• linux/errno.h
• linux/filelock.h
• linux/pagemap.h
• linux/uio.h
• udf_i.h
• udf_sb.h

Detected Declarations

• function udf_page_mkwrite
• function udf_file_write_iter
• function udf_ioctl
• function udf_release_file
• function udf_file_mmap
• function udf_fsync
• function udf_setattr

Annotated Snippet

const struct file_operations udf_file_operations = {
	.read_iter		= generic_file_read_iter,
	.unlocked_ioctl		= udf_ioctl,
	.open			= generic_file_open,
	.mmap			= udf_file_mmap,
	.write_iter		= udf_file_write_iter,
	.release		= udf_release_file,
	.fsync			= udf_fsync,
	.splice_read		= filemap_splice_read,
	.splice_write		= iter_file_splice_write,
	.llseek			= generic_file_llseek,
	.setlease		= generic_setlease,
};

static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
		       struct iattr *attr)
{
	struct inode *inode = d_inode(dentry);
	struct super_block *sb = inode->i_sb;
	int error;

	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
	if (error)
		return error;

	if ((attr->ia_valid & ATTR_UID) &&
	    UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
	    !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
		return -EPERM;
	if ((attr->ia_valid & ATTR_GID) &&
	    UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
	    !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
		return -EPERM;

	if ((attr->ia_valid & ATTR_SIZE) &&
	    attr->ia_size != i_size_read(inode)) {
		filemap_invalidate_lock(inode->i_mapping);
		error = udf_setsize(inode, attr->ia_size);
		filemap_invalidate_unlock(inode->i_mapping);
		if (error)
			return error;
	}

	if (attr->ia_valid & ATTR_MODE)
		udf_update_extra_perms(inode, attr->ia_mode);

	setattr_copy(&nop_mnt_idmap, inode, attr);
	mark_inode_dirty(inode);
	return 0;
}

const struct inode_operations udf_file_inode_operations = {
	.setattr		= udf_setattr,
};

Annotation

• Immediate include surface: `udfdecl.h`, `linux/fs.h`, `linux/uaccess.h`, `linux/kernel.h`, `linux/string.h`, `linux/capability.h`, `linux/errno.h`, `linux/filelock.h`.
• Detected declarations: `function udf_page_mkwrite`, `function udf_file_write_iter`, `function udf_ioctl`, `function udf_release_file`, `function udf_file_mmap`, `function udf_fsync`, `function udf_setattr`.
• 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.