1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun /* -*- mode: c; c-basic-offset: 8; -*- 3*4882a593Smuzhiyun * vim: noexpandtab sw=8 ts=8 sts=0: 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * reservations.h 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Allocation reservations function prototypes and structures. 8*4882a593Smuzhiyun * 9*4882a593Smuzhiyun * Copyright (C) 2010 Novell. All rights reserved. 10*4882a593Smuzhiyun */ 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun #ifndef OCFS2_RESERVATIONS_H 13*4882a593Smuzhiyun #define OCFS2_RESERVATIONS_H 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun #include <linux/rbtree.h> 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun #define OCFS2_DEFAULT_RESV_LEVEL 2 18*4882a593Smuzhiyun #define OCFS2_MAX_RESV_LEVEL 9 19*4882a593Smuzhiyun #define OCFS2_MIN_RESV_LEVEL 0 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun struct ocfs2_alloc_reservation { 22*4882a593Smuzhiyun struct rb_node r_node; 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun unsigned int r_start; /* Beginning of current window */ 25*4882a593Smuzhiyun unsigned int r_len; /* Length of the window */ 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun unsigned int r_last_len; /* Length of most recent alloc */ 28*4882a593Smuzhiyun unsigned int r_last_start; /* Start of most recent alloc */ 29*4882a593Smuzhiyun struct list_head r_lru; /* LRU list head */ 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun unsigned int r_flags; 32*4882a593Smuzhiyun }; 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun #define OCFS2_RESV_FLAG_INUSE 0x01 /* Set when r_node is part of a btree */ 35*4882a593Smuzhiyun #define OCFS2_RESV_FLAG_TMP 0x02 /* Temporary reservation, will be 36*4882a593Smuzhiyun * destroyed immedately after use */ 37*4882a593Smuzhiyun #define OCFS2_RESV_FLAG_DIR 0x04 /* Reservation is for an unindexed 38*4882a593Smuzhiyun * directory btree */ 39*4882a593Smuzhiyun 40*4882a593Smuzhiyun struct ocfs2_reservation_map { 41*4882a593Smuzhiyun struct rb_root m_reservations; 42*4882a593Smuzhiyun char *m_disk_bitmap; 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun struct ocfs2_super *m_osb; 45*4882a593Smuzhiyun 46*4882a593Smuzhiyun /* The following are not initialized to meaningful values until a disk 47*4882a593Smuzhiyun * bitmap is provided. */ 48*4882a593Smuzhiyun u32 m_bitmap_len; /* Number of valid 49*4882a593Smuzhiyun * bits available */ 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun struct list_head m_lru; /* LRU of reservations 52*4882a593Smuzhiyun * structures. */ 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun }; 55*4882a593Smuzhiyun 56*4882a593Smuzhiyun void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv); 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun #define OCFS2_RESV_TYPES (OCFS2_RESV_FLAG_TMP|OCFS2_RESV_FLAG_DIR) 59*4882a593Smuzhiyun void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv, 60*4882a593Smuzhiyun unsigned int flags); 61*4882a593Smuzhiyun 62*4882a593Smuzhiyun int ocfs2_dir_resv_allowed(struct ocfs2_super *osb); 63*4882a593Smuzhiyun 64*4882a593Smuzhiyun /** 65*4882a593Smuzhiyun * ocfs2_resv_discard() - truncate a reservation 66*4882a593Smuzhiyun * @resmap: 67*4882a593Smuzhiyun * @resv: the reservation to truncate. 68*4882a593Smuzhiyun * 69*4882a593Smuzhiyun * After this function is called, the reservation will be empty, and 70*4882a593Smuzhiyun * unlinked from the rbtree. 71*4882a593Smuzhiyun */ 72*4882a593Smuzhiyun void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap, 73*4882a593Smuzhiyun struct ocfs2_alloc_reservation *resv); 74*4882a593Smuzhiyun 75*4882a593Smuzhiyun 76*4882a593Smuzhiyun /** 77*4882a593Smuzhiyun * ocfs2_resmap_init() - Initialize fields of a reservations bitmap 78*4882a593Smuzhiyun * @resmap: struct ocfs2_reservation_map to initialize 79*4882a593Smuzhiyun * @obj: unused for now 80*4882a593Smuzhiyun * @ops: unused for now 81*4882a593Smuzhiyun * @max_bitmap_bytes: Maximum size of the bitmap (typically blocksize) 82*4882a593Smuzhiyun * 83*4882a593Smuzhiyun * Only possible return value other than '0' is -ENOMEM for failure to 84*4882a593Smuzhiyun * allocation mirror bitmap. 85*4882a593Smuzhiyun */ 86*4882a593Smuzhiyun int ocfs2_resmap_init(struct ocfs2_super *osb, 87*4882a593Smuzhiyun struct ocfs2_reservation_map *resmap); 88*4882a593Smuzhiyun 89*4882a593Smuzhiyun /** 90*4882a593Smuzhiyun * ocfs2_resmap_restart() - "restart" a reservation bitmap 91*4882a593Smuzhiyun * @resmap: reservations bitmap 92*4882a593Smuzhiyun * @clen: Number of valid bits in the bitmap 93*4882a593Smuzhiyun * @disk_bitmap: the disk bitmap this resmap should refer to. 94*4882a593Smuzhiyun * 95*4882a593Smuzhiyun * Re-initialize the parameters of a reservation bitmap. This is 96*4882a593Smuzhiyun * useful for local alloc window slides. 97*4882a593Smuzhiyun * 98*4882a593Smuzhiyun * This function will call ocfs2_trunc_resv against all existing 99*4882a593Smuzhiyun * reservations. A future version will recalculate existing 100*4882a593Smuzhiyun * reservations based on the new bitmap. 101*4882a593Smuzhiyun */ 102*4882a593Smuzhiyun void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap, 103*4882a593Smuzhiyun unsigned int clen, char *disk_bitmap); 104*4882a593Smuzhiyun 105*4882a593Smuzhiyun /** 106*4882a593Smuzhiyun * ocfs2_resmap_uninit() - uninitialize a reservation bitmap structure 107*4882a593Smuzhiyun * @resmap: the struct ocfs2_reservation_map to uninitialize 108*4882a593Smuzhiyun */ 109*4882a593Smuzhiyun void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap); 110*4882a593Smuzhiyun 111*4882a593Smuzhiyun /** 112*4882a593Smuzhiyun * ocfs2_resmap_resv_bits() - Return still-valid reservation bits 113*4882a593Smuzhiyun * @resmap: reservations bitmap 114*4882a593Smuzhiyun * @resv: reservation to base search from 115*4882a593Smuzhiyun * @cstart: start of proposed allocation 116*4882a593Smuzhiyun * @clen: length (in clusters) of proposed allocation 117*4882a593Smuzhiyun * 118*4882a593Smuzhiyun * Using the reservation data from resv, this function will compare 119*4882a593Smuzhiyun * resmap and resmap->m_disk_bitmap to determine what part (if any) of 120*4882a593Smuzhiyun * the reservation window is still clear to use. If resv is empty, 121*4882a593Smuzhiyun * this function will try to allocate a window for it. 122*4882a593Smuzhiyun * 123*4882a593Smuzhiyun * On success, zero is returned and the valid allocation area is set in cstart 124*4882a593Smuzhiyun * and clen. 125*4882a593Smuzhiyun * 126*4882a593Smuzhiyun * Returns -ENOSPC if reservations are disabled. 127*4882a593Smuzhiyun */ 128*4882a593Smuzhiyun int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap, 129*4882a593Smuzhiyun struct ocfs2_alloc_reservation *resv, 130*4882a593Smuzhiyun int *cstart, int *clen); 131*4882a593Smuzhiyun 132*4882a593Smuzhiyun /** 133*4882a593Smuzhiyun * ocfs2_resmap_claimed_bits() - Tell the reservation code that bits were used. 134*4882a593Smuzhiyun * @resmap: reservations bitmap 135*4882a593Smuzhiyun * @resv: optional reservation to recalulate based on new bitmap 136*4882a593Smuzhiyun * @cstart: start of allocation in clusters 137*4882a593Smuzhiyun * @clen: end of allocation in clusters. 138*4882a593Smuzhiyun * 139*4882a593Smuzhiyun * Tell the reservation code that bits were used to fulfill allocation in 140*4882a593Smuzhiyun * resmap. The bits don't have to have been part of any existing 141*4882a593Smuzhiyun * reservation. But we must always call this function when bits are claimed. 142*4882a593Smuzhiyun * Internally, the reservations code will use this information to mark the 143*4882a593Smuzhiyun * reservations bitmap. If resv is passed, it's next allocation window will be 144*4882a593Smuzhiyun * calculated. It also expects that 'cstart' is the same as we passed back 145*4882a593Smuzhiyun * from ocfs2_resmap_resv_bits(). 146*4882a593Smuzhiyun */ 147*4882a593Smuzhiyun void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap, 148*4882a593Smuzhiyun struct ocfs2_alloc_reservation *resv, 149*4882a593Smuzhiyun u32 cstart, u32 clen); 150*4882a593Smuzhiyun 151*4882a593Smuzhiyun #endif /* OCFS2_RESERVATIONS_H */ 152