fs/dlm/dlm_internal.h

Source file repositories/reference/linux-study-clean/fs/dlm/dlm_internal.h

File Facts

System
Linux kernel
Corpus path
fs/dlm/dlm_internal.h
Extension
.h
Size
23125 bytes
Lines
834
Domain
Core OS
Bucket
VFS And Filesystem Core
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 dlm_member {
	struct list_head	list;
	int			nodeid;
	int			weight;
	int			slot;
	int			slot_prev;
	int			comm_seq;
	uint32_t		generation;
};

/*
 * Save and manage recovery state for a lockspace.
 */

struct dlm_recover {
	struct list_head	list;
	struct dlm_config_node	*nodes;
	int			nodes_count;
	uint64_t		seq;
};

/*
 * Pass input args to second stage locking function.
 */

struct dlm_args {
	uint32_t		flags;
	void			(*astfn) (void *astparam);
	void			*astparam;
	void			(*bastfn) (void *astparam, int mode);
	int			mode;
	struct dlm_lksb		*lksb;
};


/*
 * Lock block
 *
 * A lock can be one of three types:
 *
 * local copy      lock is mastered locally
 *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
 * process copy    lock is mastered on a remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
 * master copy     master node's copy of a lock owned by remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
 *
 * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
 * dlm_unlock.  The dlm does not modify these or use any private flags in
 * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
 * are sent as-is to the remote master when the lock is remote.
 *
 * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
 * Some internal flags are shared between the master and process nodes;
 * these shared flags are kept in the lower two bytes.  One of these
 * flags set on the master copy will be propagated to the process copy
 * and v.v.  Other internal flags are private to the master or process
 * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
 *
 * lkb_sbflags: status block flags.  These flags are copied directly into
 * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
 * ast.  All defined in dlm.h with DLM_SBF_ prefix.
 *
 * lkb_status: the lock status indicates which rsb queue the lock is
 * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
 *
 * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
 * reply is needed.  Only set when the lkb is on the lockspace waiters
 * list awaiting a reply from a remote node.
 *
 * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
 * is a master copy, nodeid specifies the remote lock holder, when the
 * lkb is a process copy, the nodeid specifies the lock master.
 */

/* lkb_status */

#define DLM_LKSTS_WAITING	1
#define DLM_LKSTS_GRANTED	2
#define DLM_LKSTS_CONVERT	3

/* lkb_iflags */

#define DLM_IFL_MSTCPY_BIT	16
#define __DLM_IFL_MIN_BIT	DLM_IFL_MSTCPY_BIT
#define DLM_IFL_RESEND_BIT	17
#define DLM_IFL_DEAD_BIT	18
#define DLM_IFL_OVERLAP_UNLOCK_BIT 19
#define DLM_IFL_OVERLAP_CANCEL_BIT 20
#define DLM_IFL_ENDOFLIFE_BIT	21

Annotation

Implementation Notes