145 строки
4.7 KiB
C
145 строки
4.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* reservations.h
|
|
*
|
|
* Allocation reservations function prototypes and structures.
|
|
*
|
|
* Copyright (C) 2010 Novell. All rights reserved.
|
|
*/
|
|
|
|
#ifndef OCFS2_RESERVATIONS_H
|
|
#define OCFS2_RESERVATIONS_H
|
|
|
|
#include <linux/rbtree.h>
|
|
|
|
#define OCFS2_DEFAULT_RESV_LEVEL 2
|
|
#define OCFS2_MAX_RESV_LEVEL 9
|
|
#define OCFS2_MIN_RESV_LEVEL 0
|
|
|
|
struct ocfs2_alloc_reservation {
|
|
struct rb_node r_node;
|
|
|
|
unsigned int r_start; /* Beginning of current window */
|
|
unsigned int r_len; /* Length of the window */
|
|
|
|
unsigned int r_last_len; /* Length of most recent alloc */
|
|
unsigned int r_last_start; /* Start of most recent alloc */
|
|
struct list_head r_lru; /* LRU list head */
|
|
|
|
unsigned int r_flags;
|
|
};
|
|
|
|
#define OCFS2_RESV_FLAG_INUSE 0x01 /* Set when r_node is part of a btree */
|
|
#define OCFS2_RESV_FLAG_TMP 0x02 /* Temporary reservation, will be
|
|
* destroyed immedately after use */
|
|
#define OCFS2_RESV_FLAG_DIR 0x04 /* Reservation is for an unindexed
|
|
* directory btree */
|
|
|
|
struct ocfs2_reservation_map {
|
|
struct rb_root m_reservations;
|
|
char *m_disk_bitmap;
|
|
|
|
struct ocfs2_super *m_osb;
|
|
|
|
/* The following are not initialized to meaningful values until a disk
|
|
* bitmap is provided. */
|
|
u32 m_bitmap_len; /* Number of valid
|
|
* bits available */
|
|
|
|
struct list_head m_lru; /* LRU of reservations
|
|
* structures. */
|
|
|
|
};
|
|
|
|
void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv);
|
|
|
|
#define OCFS2_RESV_TYPES (OCFS2_RESV_FLAG_TMP|OCFS2_RESV_FLAG_DIR)
|
|
void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv,
|
|
unsigned int flags);
|
|
|
|
int ocfs2_dir_resv_allowed(struct ocfs2_super *osb);
|
|
|
|
/**
|
|
* ocfs2_resv_discard() - truncate a reservation
|
|
* @resmap:
|
|
* @resv: the reservation to truncate.
|
|
*
|
|
* After this function is called, the reservation will be empty, and
|
|
* unlinked from the rbtree.
|
|
*/
|
|
void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
|
|
struct ocfs2_alloc_reservation *resv);
|
|
|
|
|
|
/**
|
|
* ocfs2_resmap_init() - Initialize fields of a reservations bitmap
|
|
* @osb: struct ocfs2_super to be saved in resmap
|
|
* @resmap: struct ocfs2_reservation_map to initialize
|
|
*/
|
|
void ocfs2_resmap_init(struct ocfs2_super *osb,
|
|
struct ocfs2_reservation_map *resmap);
|
|
|
|
/**
|
|
* ocfs2_resmap_restart() - "restart" a reservation bitmap
|
|
* @resmap: reservations bitmap
|
|
* @clen: Number of valid bits in the bitmap
|
|
* @disk_bitmap: the disk bitmap this resmap should refer to.
|
|
*
|
|
* Re-initialize the parameters of a reservation bitmap. This is
|
|
* useful for local alloc window slides.
|
|
*
|
|
* This function will call ocfs2_trunc_resv against all existing
|
|
* reservations. A future version will recalculate existing
|
|
* reservations based on the new bitmap.
|
|
*/
|
|
void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap,
|
|
unsigned int clen, char *disk_bitmap);
|
|
|
|
/**
|
|
* ocfs2_resmap_uninit() - uninitialize a reservation bitmap structure
|
|
* @resmap: the struct ocfs2_reservation_map to uninitialize
|
|
*/
|
|
void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap);
|
|
|
|
/**
|
|
* ocfs2_resmap_resv_bits() - Return still-valid reservation bits
|
|
* @resmap: reservations bitmap
|
|
* @resv: reservation to base search from
|
|
* @cstart: start of proposed allocation
|
|
* @clen: length (in clusters) of proposed allocation
|
|
*
|
|
* Using the reservation data from resv, this function will compare
|
|
* resmap and resmap->m_disk_bitmap to determine what part (if any) of
|
|
* the reservation window is still clear to use. If resv is empty,
|
|
* this function will try to allocate a window for it.
|
|
*
|
|
* On success, zero is returned and the valid allocation area is set in cstart
|
|
* and clen.
|
|
*
|
|
* Returns -ENOSPC if reservations are disabled.
|
|
*/
|
|
int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
|
|
struct ocfs2_alloc_reservation *resv,
|
|
int *cstart, int *clen);
|
|
|
|
/**
|
|
* ocfs2_resmap_claimed_bits() - Tell the reservation code that bits were used.
|
|
* @resmap: reservations bitmap
|
|
* @resv: optional reservation to recalulate based on new bitmap
|
|
* @cstart: start of allocation in clusters
|
|
* @clen: end of allocation in clusters.
|
|
*
|
|
* Tell the reservation code that bits were used to fulfill allocation in
|
|
* resmap. The bits don't have to have been part of any existing
|
|
* reservation. But we must always call this function when bits are claimed.
|
|
* Internally, the reservations code will use this information to mark the
|
|
* reservations bitmap. If resv is passed, it's next allocation window will be
|
|
* calculated. It also expects that 'cstart' is the same as we passed back
|
|
* from ocfs2_resmap_resv_bits().
|
|
*/
|
|
void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap,
|
|
struct ocfs2_alloc_reservation *resv,
|
|
u32 cstart, u32 clen);
|
|
|
|
#endif /* OCFS2_RESERVATIONS_H */
|