sys/ufs/chfs/chfs_erase.c

   1 /*      $NetBSD: chfs_erase.c,v 1.1 2011/11/24 15:51:31 ahoka 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 /*
  35  * chfs_erase.c
  36  *
  37  * Copyright (C) 2010  David Tengeri <dtengeri@inf.u-szeged.hu>,
  38  *                     ...
  39  *                     University of Szeged, Hungary
  40  */
  41
  42 #include "chfs.h"
  43
  44
  45 /**
  46  * chfs_remap_leb - unmap and then map a leb
  47  * @chmp: chfs mount structure
  48  *
  49  * This function gets an eraseblock from the erasable queue, unmaps it through
  50  * EBH and maps another eraseblock to the same LNR.
  51  * EBH will find a free eraseblock if any or will erase one if there isn't any
  52  * free, just dirty block.
  53  *
  54  * Returns zero on case of success, errorcode otherwise.
  55  *
  56  * Needs more brainstorming here.
  57  */
  58 int
  59 chfs_remap_leb(struct chfs_mount *chmp)
  60 {
  61         int err;
  62         struct chfs_eraseblock *cheb;
  63         dbg("chfs_remap_leb\n");
  64         uint32_t dirty, unchecked, used, free, wasted;
  65
  66         //dbg("chmp->chm_nr_erasable_blocks: %d\n", chmp->chm_nr_erasable_blocks);
  67         //dbg("ltree: %p ecl: %p\n", &chmp->chm_ebh->ltree_lock, &chmp->chm_lock_sizes);
  68         KASSERT(!rw_write_held(&chmp->chm_lock_wbuf));
  69         KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
  70         KASSERT(mutex_owned(&chmp->chm_lock_sizes));
  71
  72         if (!chmp->chm_nr_erasable_blocks) {
  73                 //TODO
  74                 /* We don't have any erasable blocks, need to check if there are
  75                  * blocks on erasable_pending_wbuf_queue, flush the data and then
  76                  * we can remap it.
  77                  * If there aren't any blocks on that list too, we need to GC?
  78                  */
  79                 if (!TAILQ_EMPTY(&chmp->chm_erasable_pending_wbuf_queue)) {
  80                         cheb = TAILQ_FIRST(&chmp->chm_erasable_pending_wbuf_queue);
  81                         TAILQ_REMOVE(&chmp->chm_erasable_pending_wbuf_queue, cheb, queue);
  82                         if (chmp->chm_wbuf_len) {
  83                                 mutex_exit(&chmp->chm_lock_sizes);
  84                                 chfs_flush_pending_wbuf(chmp);
  85                                 mutex_enter(&chmp->chm_lock_sizes);
  86                         }
  87                         TAILQ_INSERT_TAIL(&chmp->chm_erase_pending_queue, cheb, queue);
  88                         chmp->chm_nr_erasable_blocks++;
  89                 } else {
  90                         /* We can't delete any block. */
  91                         //FIXME should we return ENOSPC?
  92                         return ENOSPC;
  93                 }
  94         }
  95         cheb = TAILQ_FIRST(&chmp->chm_erase_pending_queue);
  96         TAILQ_REMOVE(&chmp->chm_erase_pending_queue, cheb, queue);
  97         chmp->chm_nr_erasable_blocks--;
  98
  99         dirty = cheb->dirty_size;
 100         unchecked = cheb->unchecked_size;
 101         used = cheb->used_size;
 102         free = cheb->free_size;
 103         wasted = cheb->wasted_size;
 104
 105         // Free allocated node references for this eraseblock
 106         chfs_free_node_refs(cheb);
 107
 108         err = chfs_unmap_leb(chmp, cheb->lnr);
 109         if (err)
 110                 return err;
 111
 112         err = chfs_map_leb(chmp, cheb->lnr);
 113         if (err)
 114                 return err;
 115         // Reset state to default and change chmp sizes too
 116         chfs_change_size_dirty(chmp, cheb, -dirty);
 117         chfs_change_size_unchecked(chmp, cheb, -unchecked);
 118         chfs_change_size_used(chmp, cheb, -used);
 119         chfs_change_size_free(chmp, cheb, chmp->chm_ebh->eb_size - free);
 120         chfs_change_size_wasted(chmp, cheb, -wasted);
 121
 122         KASSERT(cheb->dirty_size == 0);
 123         KASSERT(cheb->unchecked_size == 0);
 124         KASSERT(cheb->used_size == 0);
 125         KASSERT(cheb->free_size == chmp->chm_ebh->eb_size);
 126         KASSERT(cheb->wasted_size == 0);
 127
 128         cheb->first_node = NULL;
 129         cheb->last_node  = NULL;
 130         //put it to free_queue
 131         TAILQ_INSERT_TAIL(&chmp->chm_free_queue, cheb, queue);
 132         chmp->chm_nr_free_blocks++;
 133         dbg("remaped (free: %d, erasable: %d)\n", chmp->chm_nr_free_blocks, chmp->chm_nr_erasable_blocks);
 134         KASSERT(!TAILQ_EMPTY(&chmp->chm_free_queue));
 135
 136         return 0;
 137 }