[mirror_ubuntu-jammy-kernel.git] / fs / ocfs2 / reservations.h

/* 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
 * @resmap: struct ocfs2_reservation_map to initialize
 * @obj: unused for now
 * @ops: unused for now
 * @max_bitmap_bytes: Maximum size of the bitmap (typically blocksize)
 *
 * Only possible return value other than '0' is -ENOMEM for failure to
 * allocation mirror bitmap.
 */
int 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 */
Commit	Line	Data
1802d0be	1	/* SPDX-License-Identifier: GPL-2.0-only */
fa60ce2c	2	/*
d02f00cc MF	3	* reservations.h
	4	*
	5	* Allocation reservations function prototypes and structures.
	6	*
	7	* Copyright (C) 2010 Novell. All rights reserved.
d02f00cc MF	8	*/
	9
	10	#ifndef OCFS2_RESERVATIONS_H
	11	#define OCFS2_RESERVATIONS_H
	12
	13	#include <linux/rbtree.h>
	14
b07f8f24	15	#define OCFS2_DEFAULT_RESV_LEVEL 2
d02f00cc MF	16	#define OCFS2_MAX_RESV_LEVEL 9
	17	#define OCFS2_MIN_RESV_LEVEL 0
	18
	19	struct ocfs2_alloc_reservation {
	20	struct rb_node r_node;
	21
25985edc	22	unsigned int r_start; /* Beginning of current window */
d02f00cc MF	23	unsigned int r_len; /* Length of the window */
	24
	25	unsigned int r_last_len; /* Length of most recent alloc */
	26	unsigned int r_last_start; /* Start of most recent alloc */
	27	struct list_head r_lru; /* LRU list head */
	28
	29	unsigned int r_flags;
	30	};
	31
	32	#define OCFS2_RESV_FLAG_INUSE 0x01 /* Set when r_node is part of a btree */
	33	#define OCFS2_RESV_FLAG_TMP 0x02 /* Temporary reservation, will be
	34	* destroyed immedately after use */
e3b4a97d MF	35	#define OCFS2_RESV_FLAG_DIR 0x04 /* Reservation is for an unindexed
e3b4a97d MF	36	* directory btree */
d02f00cc MF	37
	38	struct ocfs2_reservation_map {
	39	struct rb_root m_reservations;
	40	char *m_disk_bitmap;
	41
	42	struct ocfs2_super *m_osb;
	43
	44	/* The following are not initialized to meaningful values until a disk
	45	* bitmap is provided. */
	46	u32 m_bitmap_len; /* Number of valid
	47	* bits available */
	48
	49	struct list_head m_lru; /* LRU of reservations
	50	* structures. */
	51
	52	};
	53
	54	void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv);
	55
e3b4a97d	56	#define OCFS2_RESV_TYPES (OCFS2_RESV_FLAG_TMP\|OCFS2_RESV_FLAG_DIR)
d02f00cc MF	57	void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv,
	58	unsigned int flags);
	59
83f92318 MF	60	int ocfs2_dir_resv_allowed(struct ocfs2_super *osb);
83f92318 MF	61
d02f00cc MF	62	/**
	63	* ocfs2_resv_discard() - truncate a reservation
	64	* @resmap:
	65	* @resv: the reservation to truncate.
	66	*
	67	* After this function is called, the reservation will be empty, and
	68	* unlinked from the rbtree.
	69	*/
	70	void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
	71	struct ocfs2_alloc_reservation *resv);
	72
	73
	74	/**
	75	* ocfs2_resmap_init() - Initialize fields of a reservations bitmap
	76	* @resmap: struct ocfs2_reservation_map to initialize
	77	* @obj: unused for now
	78	* @ops: unused for now
	79	* @max_bitmap_bytes: Maximum size of the bitmap (typically blocksize)
	80	*
	81	* Only possible return value other than '0' is -ENOMEM for failure to
	82	* allocation mirror bitmap.
	83	*/
	84	int ocfs2_resmap_init(struct ocfs2_super *osb,
	85	struct ocfs2_reservation_map *resmap);
	86
	87	/**
	88	* ocfs2_resmap_restart() - "restart" a reservation bitmap
	89	* @resmap: reservations bitmap
	90	* @clen: Number of valid bits in the bitmap
	91	* @disk_bitmap: the disk bitmap this resmap should refer to.
	92	*
	93	* Re-initialize the parameters of a reservation bitmap. This is
	94	* useful for local alloc window slides.
	95	*
	96	* This function will call ocfs2_trunc_resv against all existing
	97	* reservations. A future version will recalculate existing
	98	* reservations based on the new bitmap.
	99	*/
	100	void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap,
	101	unsigned int clen, char *disk_bitmap);
	102
	103	/**
	104	* ocfs2_resmap_uninit() - uninitialize a reservation bitmap structure
	105	* @resmap: the struct ocfs2_reservation_map to uninitialize
	106	*/
	107	void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap);
	108
	109	/**
	110	* ocfs2_resmap_resv_bits() - Return still-valid reservation bits
	111	* @resmap: reservations bitmap
	112	* @resv: reservation to base search from
	113	* @cstart: start of proposed allocation
	114	* @clen: length (in clusters) of proposed allocation
	115	*
	116	* Using the reservation data from resv, this function will compare
	117	* resmap and resmap->m_disk_bitmap to determine what part (if any) of
	118	* the reservation window is still clear to use. If resv is empty,
	119	* this function will try to allocate a window for it.
	120	*
	121	* On success, zero is returned and the valid allocation area is set in cstart
	122	* and clen.
	123	*
	124	* Returns -ENOSPC if reservations are disabled.
	125	*/
126	int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
127	struct ocfs2_alloc_reservation *resv,
128	int cstart, int clen);
129
130	/**
131	* ocfs2_resmap_claimed_bits() - Tell the reservation code that bits were used.
132	* @resmap: reservations bitmap
133	* @resv: optional reservation to recalulate based on new bitmap
134	* @cstart: start of allocation in clusters
135	* @clen: end of allocation in clusters.
136	*
137	* Tell the reservation code that bits were used to fulfill allocation in
138	* resmap. The bits don't have to have been part of any existing
139	* reservation. But we must always call this function when bits are claimed.
140	* Internally, the reservations code will use this information to mark the
141	* reservations bitmap. If resv is passed, it's next allocation window will be
b065556a TM	142	* calculated. It also expects that 'cstart' is the same as we passed back
b065556a TM	143	* from ocfs2_resmap_resv_bits().
d02f00cc MF	144	*/
	145	void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap,
	146	struct ocfs2_alloc_reservation *resv,
	147	u32 cstart, u32 clen);
	148
	149	#endif /* OCFS2_RESERVATIONS_H */