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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 |
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); |
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 |
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 */ |