sys/ufs/chfs/chfs_erase.c

   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
  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 }