1 /* $NetBSD: chfs_erase.c,v 1.2 2012/10/19 12:44:39 ttoth Exp $ */
2
3 /*-
4 * Copyright (c) 2010 Department of Software Engineering,
5 * University of Szeged, Hungary
6 * Copyright (c) 2010 David Tengeri <dtengeri@inf.u-szeged.hu>
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by the Department of Software Engineering, University of Szeged, Hungary
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "chfs.h"
35
36
37 /*
38 * chfs_remap_leb - unmap and then map a leb
39 *
40 * Gets an eraseblock from the erasable queue, unmaps it through
41 * EBH and maps another eraseblock to the same LNR.
42 * EBH will find a free eraseblock if any or will erase one if there isn't any
43 * free, just dirty block.
44 *
45 * Needs more brainstorming here.
46 */
47 int
chfs_remap_leb(struct chfs_mount * chmp)48 chfs_remap_leb(struct chfs_mount *chmp)
49 {
50 int err;
51 struct chfs_eraseblock *cheb;
52 dbg("chfs_remap_leb\n");
53 uint32_t dirty, unchecked, used, free, wasted;
54
55 KASSERT(!rw_write_held(&chmp->chm_lock_wbuf));
56 KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
57 KASSERT(mutex_owned(&chmp->chm_lock_sizes));
58
59 if (!chmp->chm_nr_erasable_blocks) {
60 //TODO
61 /* We don't have any erasable blocks, need to check if there are
62 * blocks on erasable_pending_wbuf_queue, flush the data and then
63 * we can remap it.
64 * If there aren't any blocks on that list too, we need to GC?
65 */
66 if (!TAILQ_EMPTY(&chmp->chm_erasable_pending_wbuf_queue)) {
67 cheb = TAILQ_FIRST(&chmp->chm_erasable_pending_wbuf_queue);
68 TAILQ_REMOVE(&chmp->chm_erasable_pending_wbuf_queue, cheb, queue);
69 if (chmp->chm_wbuf_len) {
70 mutex_exit(&chmp->chm_lock_sizes);
71 chfs_flush_pending_wbuf(chmp);
72 mutex_enter(&chmp->chm_lock_sizes);
73 }
74 TAILQ_INSERT_TAIL(&chmp->chm_erase_pending_queue, cheb, queue);
75 chmp->chm_nr_erasable_blocks++;
76 } else {
77 /* We can't delete any block. */
78 //FIXME should we return ENOSPC?
79 return ENOSPC;
80 }
81 }
82 cheb = TAILQ_FIRST(&chmp->chm_erase_pending_queue);
83 TAILQ_REMOVE(&chmp->chm_erase_pending_queue, cheb, queue);
84 chmp->chm_nr_erasable_blocks--;
85
86 dirty = cheb->dirty_size;
87 unchecked = cheb->unchecked_size;
88 used = cheb->used_size;
89 free = cheb->free_size;
90 wasted = cheb->wasted_size;
91
92 /* Free allocated node references for this eraseblock */
93 chfs_free_node_refs(cheb);
94
95 err = chfs_unmap_leb(chmp, cheb->lnr);
96 if (err)
97 return err;
98
99 err = chfs_map_leb(chmp, cheb->lnr);
100 if (err)
101 return err;
102 /* Reset state to default and change chmp sizes too */
103 chfs_change_size_dirty(chmp, cheb, -dirty);
104 chfs_change_size_unchecked(chmp, cheb, -unchecked);
105 chfs_change_size_used(chmp, cheb, -used);
106 chfs_change_size_free(chmp, cheb, chmp->chm_ebh->eb_size - free);
107 chfs_change_size_wasted(chmp, cheb, -wasted);
108
109 KASSERT(cheb->dirty_size == 0);
110 KASSERT(cheb->unchecked_size == 0);
111 KASSERT(cheb->used_size == 0);
112 KASSERT(cheb->free_size == chmp->chm_ebh->eb_size);
113 KASSERT(cheb->wasted_size == 0);
114
115 cheb->first_node = NULL;
116 cheb->last_node = NULL;
117 /* put it to free_queue */
118 TAILQ_INSERT_TAIL(&chmp->chm_free_queue, cheb, queue);
119 chmp->chm_nr_free_blocks++;
120 dbg("remaped (free: %d, erasable: %d)\n", chmp->chm_nr_free_blocks, chmp->chm_nr_erasable_blocks);
121 KASSERT(!TAILQ_EMPTY(&chmp->chm_free_queue));
122
123 return 0;
124 }
125