include/linux/quota.h

Source file repositories/reference/linux-study-clean/include/linux/quota.h

File Facts

System
Linux kernel
Corpus path
include/linux/quota.h
Extension
.h
Size
19211 bytes
Lines
544
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct kqid {			/* Type in which we store the quota identifier */
	union {
		kuid_t uid;
		kgid_t gid;
		kprojid_t projid;
	};
	enum quota_type type;  /* USRQUOTA (uid) or GRPQUOTA (gid) or PRJQUOTA (projid) */
};

extern bool qid_eq(struct kqid left, struct kqid right);
extern bool qid_lt(struct kqid left, struct kqid right);
extern qid_t from_kqid(struct user_namespace *to, struct kqid qid);
extern qid_t from_kqid_munged(struct user_namespace *to, struct kqid qid);
extern bool qid_valid(struct kqid qid);

/**
 *	make_kqid - Map a user-namespace, type, qid tuple into a kqid.
 *	@from: User namespace that the qid is in
 *	@type: The type of quota
 *	@qid: Quota identifier
 *
 *	Maps a user-namespace, type qid tuple into a kernel internal
 *	kqid, and returns that kqid.
 *
 *	When there is no mapping defined for the user-namespace, type,
 *	qid tuple an invalid kqid is returned.  Callers are expected to
 *	test for and handle invalid kqids being returned.
 *	Invalid kqids may be tested for using qid_valid().
 */
static inline struct kqid make_kqid(struct user_namespace *from,
				    enum quota_type type, qid_t qid)
{
	struct kqid kqid;

	kqid.type = type;
	switch (type) {
	case USRQUOTA:
		kqid.uid = make_kuid(from, qid);
		break;
	case GRPQUOTA:
		kqid.gid = make_kgid(from, qid);
		break;
	case PRJQUOTA:
		kqid.projid = make_kprojid(from, qid);
		break;
	default:
		BUG();
	}
	return kqid;
}

/**
 *	make_kqid_invalid - Explicitly make an invalid kqid
 *	@type: The type of quota identifier
 *
 *	Returns an invalid kqid with the specified type.
 */
static inline struct kqid make_kqid_invalid(enum quota_type type)
{
	struct kqid kqid;

	kqid.type = type;
	switch (type) {
	case USRQUOTA:
		kqid.uid = INVALID_UID;
		break;
	case GRPQUOTA:
		kqid.gid = INVALID_GID;
		break;
	case PRJQUOTA:
		kqid.projid = INVALID_PROJID;
		break;
	default:
		BUG();
	}
	return kqid;
}

/**
 *	make_kqid_uid - Make a kqid from a kuid
 *	@uid: The kuid to make the quota identifier from
 */
static inline struct kqid make_kqid_uid(kuid_t uid)
{
	struct kqid kqid;
	kqid.type = USRQUOTA;
	kqid.uid = uid;
	return kqid;
}

Annotation

Implementation Notes