HAMMER 43C/Many: Performance cleanup
[dragonfly.git] / sys / vfs / hammer / hammer_freemap.c
1 /*
2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
3  * 
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * 
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  * 
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  * 
34  * $DragonFly: src/sys/vfs/hammer/hammer_freemap.c,v 1.11 2008/05/13 05:04:39 dillon Exp $
35  */
36
37 /*
38  * HAMMER freemap - bigblock allocator.  The freemap is a 2-layer blockmap
39  * with one layer2 entry for each big-block in the filesystem.  Big blocks
40  * are 8MB blocks.
41  *
42  * Our allocator is fairly straightforward, we just iterate through available
43  * blocks looking for a free one.  We shortcut the iteration based on
44  * layer1 availability.
45  */
46
47 #include "hammer.h"
48
49 hammer_off_t
50 hammer_freemap_alloc(hammer_transaction_t trans, hammer_off_t owner,
51                      int *errorp)
52 {
53         hammer_volume_ondisk_t ondisk;
54         hammer_off_t layer1_offset;
55         hammer_off_t layer2_offset;
56         hammer_off_t result_offset;
57         hammer_blockmap_t blockmap;
58         hammer_buffer_t buffer1 = NULL;
59         hammer_buffer_t buffer2 = NULL;
60         struct hammer_blockmap_layer1 *layer1;
61         struct hammer_blockmap_layer2 *layer2;
62         int vol_no;
63         int loops = 0;
64
65         *errorp = 0;
66         ondisk = trans->rootvol->ondisk;
67
68         hammer_lock_ex(&trans->hmp->free_lock);
69
70         blockmap = &trans->hmp->blockmap[HAMMER_ZONE_FREEMAP_INDEX];
71         result_offset = blockmap->next_offset;
72         vol_no = HAMMER_VOL_DECODE(result_offset);
73         for (;;) { 
74                 layer1_offset = blockmap->phys_offset +
75                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
76
77                 layer1 = hammer_bread(trans->hmp, layer1_offset, errorp, &buffer1);
78                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
79                         /*
80                          * End-of-volume, try next volume.
81                          */
82 new_volume:
83                         ++vol_no;
84                         if (vol_no >= trans->hmp->nvolumes)
85                                 vol_no = 0;
86                         result_offset = HAMMER_ENCODE_RAW_BUFFER(vol_no, 0);
87                         if (vol_no == 0 && ++loops == 2) {
88                                 *errorp = ENOSPC;
89                                 result_offset = 0;
90                                 goto done;
91                         }
92                 } else {
93                         layer2_offset = layer1->phys_offset +
94                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
95                         layer2 = hammer_bread(trans->hmp, layer2_offset, errorp,
96                                               &buffer2);
97                         if (layer2->u.owner == HAMMER_BLOCKMAP_FREE) {
98                                 hammer_modify_buffer(trans, buffer2,
99                                                      layer2, sizeof(*layer2));
100                                 layer2->u.owner = owner &
101                                                 ~HAMMER_LARGEBLOCK_MASK64;
102                                 hammer_modify_buffer_done(buffer2);
103                                 hammer_modify_buffer(trans, buffer1,
104                                                      layer1, sizeof(*layer1));
105                                 --layer1->blocks_free;
106                                 hammer_modify_buffer_done(buffer1);
107                                 hammer_modify_volume_field(trans,
108                                                      trans->rootvol,
109                                                      vol0_stat_freebigblocks);
110                                 --ondisk->vol0_stat_freebigblocks;
111                                 hammer_modify_volume_done(trans->rootvol);
112                                 break;
113                         }
114                         if (layer1->blocks_free == 0 ||
115                             layer2->u.owner == HAMMER_BLOCKMAP_UNAVAIL) {
116                                 /*
117                                  * layer2 has no free blocks remaining,
118                                  * skip to the next layer.
119                                  */
120                                 result_offset = (result_offset + HAMMER_BLOCKMAP_LAYER2_MASK) & ~HAMMER_BLOCKMAP_LAYER2_MASK;
121                                 if (HAMMER_VOL_DECODE(result_offset) != vol_no)
122                                         goto new_volume;
123                         } else {
124                                 result_offset += HAMMER_LARGEBLOCK_SIZE;
125                                 if (HAMMER_VOL_DECODE(result_offset) != vol_no)
126                                         goto new_volume;
127                         }
128                 }
129         }
130         hammer_modify_volume(trans, trans->rootvol, NULL, 0);
131         blockmap->next_offset = result_offset + HAMMER_LARGEBLOCK_SIZE;
132         hammer_modify_volume_done(trans->rootvol);
133 done:
134         hammer_unlock(&trans->hmp->free_lock);
135         if (buffer1)
136                 hammer_rel_buffer(buffer1, 0);
137         if (buffer2)
138                 hammer_rel_buffer(buffer2, 0);
139         return(result_offset);
140 }
141
142 void
143 hammer_freemap_free(hammer_transaction_t trans, hammer_off_t phys_offset, 
144                     hammer_off_t owner, int *errorp)
145 {
146         hammer_volume_ondisk_t ondisk;
147         hammer_off_t layer1_offset;
148         hammer_off_t layer2_offset;
149         hammer_blockmap_t blockmap;
150         hammer_buffer_t buffer1 = NULL;
151         hammer_buffer_t buffer2 = NULL;
152         struct hammer_blockmap_layer1 *layer1;
153         struct hammer_blockmap_layer2 *layer2;
154
155         KKASSERT((phys_offset & HAMMER_LARGEBLOCK_MASK64) == 0);
156
157         hammer_uncache_buffer(trans->hmp, phys_offset);
158         *errorp = 0;
159         ondisk = trans->rootvol->ondisk;
160
161         hammer_lock_ex(&trans->hmp->free_lock);
162
163         blockmap = &trans->hmp->blockmap[HAMMER_ZONE_FREEMAP_INDEX];
164         layer1_offset = blockmap->phys_offset +
165                         HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
166         layer1 = hammer_bread(trans->hmp, layer1_offset, errorp, &buffer1);
167
168         KKASSERT(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
169
170         layer2_offset = layer1->phys_offset +
171                         HAMMER_BLOCKMAP_LAYER2_OFFSET(phys_offset);
172         layer2 = hammer_bread(trans->hmp, layer2_offset, errorp, &buffer2);
173
174         KKASSERT(layer2->u.owner == (owner & ~HAMMER_LARGEBLOCK_MASK64));
175         hammer_modify_buffer(trans, buffer1, layer1, sizeof(*layer1));
176         ++layer1->blocks_free;
177         hammer_modify_buffer_done(buffer1);
178         hammer_modify_buffer(trans, buffer2, layer2, sizeof(*layer2));
179         layer2->u.owner = HAMMER_BLOCKMAP_FREE;
180         hammer_modify_buffer_done(buffer2);
181
182         hammer_modify_volume_field(trans, trans->rootvol,
183                                    vol0_stat_freebigblocks);
184         ++ondisk->vol0_stat_freebigblocks;
185         hammer_modify_volume_done(trans->rootvol);
186
187         hammer_unlock(&trans->hmp->free_lock);
188
189         if (buffer1)
190                 hammer_rel_buffer(buffer1, 0);
191         if (buffer2)
192                 hammer_rel_buffer(buffer2, 0);
193 }
194