sys/ufs/chfs/chfs_wbuf.c

   1 /*      $NetBSD: chfs_wbuf.c,v 1.5 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 Tamas Toth <ttoth@inf.u-szeged.hu>
   7  * Copyright (C) 2010 Adam Hoka <ahoka@NetBSD.org>
   8  * All rights reserved.
   9  *
  10  * This code is derived from software contributed to The NetBSD Foundation
  11  * by the Department of Software Engineering, University of Szeged, Hungary
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR 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
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <dev/flash/flash.h>
  36 #include <sys/uio.h>
  37 #include "chfs.h"
  38
  39 #define DBG_WBUF 1              /* XXX unused, but should be */
  40
  41 #define PAD(x) (((x)+3)&~3)
  42
  43 #define EB_ADDRESS(x) ( rounddown((x), chmp->chm_ebh->eb_size) )
  44
  45 #define PAGE_DIV(x) ( rounddown((x), chmp->chm_wbuf_pagesize) )
  46 #define PAGE_MOD(x) ( (x) % (chmp->chm_wbuf_pagesize) )
  47
  48 /* writebuffer options */
  49 enum {
  50         WBUF_NOPAD,
  51         WBUF_SETPAD
  52 };
  53
  54 /*
  55  * chfs_flush_wbuf - write wbuf to the flash
  56  * Returns zero in case of success.
  57  */
  58 static int
  59 chfs_flush_wbuf(struct chfs_mount *chmp, int pad)
  60 {
  61         int ret;
  62         size_t retlen;
  63         struct chfs_node_ref *nref;
  64         struct chfs_flash_padding_node* padnode;
  65
  66         KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
  67         KASSERT(mutex_owned(&chmp->chm_lock_sizes));
  68         KASSERT(rw_write_held(&chmp->chm_lock_wbuf));
  69         KASSERT(pad == WBUF_SETPAD || pad == WBUF_NOPAD);
  70
  71         /* check padding option */
  72         if (pad == WBUF_SETPAD) {
  73                 chmp->chm_wbuf_len = PAD(chmp->chm_wbuf_len);
  74                 memset(chmp->chm_wbuf + chmp->chm_wbuf_len, 0,
  75                     chmp->chm_wbuf_pagesize - chmp->chm_wbuf_len);
  76
  77                 /* add a padding node */
  78                 padnode = (void *)(chmp->chm_wbuf + chmp->chm_wbuf_len);
  79                 padnode->magic = htole16(CHFS_FS_MAGIC_BITMASK);
  80                 padnode->type = htole16(CHFS_NODETYPE_PADDING);
  81                 padnode->length = htole32(chmp->chm_wbuf_pagesize
  82                     - chmp->chm_wbuf_len);
  83                 padnode->hdr_crc = htole32(crc32(0, (uint8_t *)padnode,
  84                         sizeof(*padnode)-4));
  85
  86                 nref = chfs_alloc_node_ref(chmp->chm_nextblock);
  87                 nref->nref_offset = chmp->chm_wbuf_ofs + chmp->chm_wbuf_len;
  88                 nref->nref_offset = CHFS_GET_OFS(nref->nref_offset) |
  89                     CHFS_OBSOLETE_NODE_MASK;
  90                 chmp->chm_wbuf_len = chmp->chm_wbuf_pagesize;
  91
  92                 /* change sizes after padding node */
  93                 chfs_change_size_free(chmp, chmp->chm_nextblock,
  94                     -padnode->length);
  95                 chfs_change_size_wasted(chmp, chmp->chm_nextblock,
  96                     padnode->length);
  97         }
  98
  99         /* write out the buffer */
 100         ret = chfs_write_leb(chmp, chmp->chm_nextblock->lnr, chmp->chm_wbuf,
 101             chmp->chm_wbuf_ofs, chmp->chm_wbuf_len, &retlen);
 102         if (ret) {
 103                 return ret;
 104         }
 105
 106         /* reset the buffer */
 107         memset(chmp->chm_wbuf, 0xff, chmp->chm_wbuf_pagesize);
 108         chmp->chm_wbuf_ofs += chmp->chm_wbuf_pagesize;
 109         chmp->chm_wbuf_len = 0;
 110
 111         return 0;
 112 }
 113
 114
 115 /*
 116  * chfs_fill_wbuf - write data to wbuf
 117  * Return the len of the buf what we didn't write to the wbuf.
 118  */
 119 static size_t
 120 chfs_fill_wbuf(struct chfs_mount *chmp, const u_char *buf, size_t len)
 121 {
 122         /* check available space */
 123         if (len && !chmp->chm_wbuf_len && (len >= chmp->chm_wbuf_pagesize)) {
 124                 return 0;
 125         }
 126         /* check buffer's length */
 127         if (len > (chmp->chm_wbuf_pagesize - chmp->chm_wbuf_len)) {
 128                 len = chmp->chm_wbuf_pagesize - chmp->chm_wbuf_len;
 129         }
 130         /* write into the wbuf */
 131         memcpy(chmp->chm_wbuf + chmp->chm_wbuf_len, buf, len);
 132
 133         /* update the actual length of writebuffer */
 134         chmp->chm_wbuf_len += (int) len;
 135         return len;
 136 }
 137
 138 /*
 139  * chfs_write_wbuf - write to wbuf and then the flash
 140  * Returns zero in case of success.
 141  */
 142 int
 143 chfs_write_wbuf(struct chfs_mount* chmp, const struct iovec *invecs, long count,
 144     off_t to, size_t *retlen)
 145 {
 146         int invec, ret = 0;
 147         size_t wbuf_retlen, donelen = 0;
 148         int outvec_to = to;
 149
 150         int lnr = chmp->chm_nextblock->lnr;
 151
 152         KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
 153         KASSERT(mutex_owned(&chmp->chm_lock_sizes));
 154         KASSERT(!rw_write_held(&chmp->chm_lock_wbuf));
 155
 156         rw_enter(&chmp->chm_lock_wbuf, RW_WRITER);
 157
 158         if (chmp->chm_wbuf_ofs == 0xffffffff) {
 159                 chmp->chm_wbuf_ofs = PAGE_DIV(to);
 160                 chmp->chm_wbuf_len = PAGE_MOD(to);
 161                 memset(chmp->chm_wbuf, 0xff, chmp->chm_wbuf_pagesize);
 162         }
 163
 164         if (EB_ADDRESS(to) != EB_ADDRESS(chmp->chm_wbuf_ofs)) {
 165                 if (chmp->chm_wbuf_len) {
 166                         ret = chfs_flush_wbuf(chmp, WBUF_SETPAD);
 167                         if (ret)
 168                                 goto outerr;
 169                 }
 170                 chmp->chm_wbuf_ofs = PAGE_DIV(to);
 171                 chmp->chm_wbuf_len = PAGE_MOD(to);
 172         }
 173
 174         if (to != PAD(chmp->chm_wbuf_ofs + chmp->chm_wbuf_len)) {
 175                 dbg("to: %llu != %zu\n", (unsigned long long)to,
 176                         PAD(chmp->chm_wbuf_ofs + chmp->chm_wbuf_len));
 177                 dbg("Non-contiguous write\n");
 178                 panic("BUG\n");
 179         }
 180
 181         /* adjust alignment offset */
 182         if (chmp->chm_wbuf_len != PAGE_MOD(to)) {
 183                 chmp->chm_wbuf_len = PAGE_MOD(to);
 184                 /* take care of alignement to next page */
 185                 if (!chmp->chm_wbuf_len) {
 186                         chmp->chm_wbuf_len += chmp->chm_wbuf_pagesize;
 187                         ret = chfs_flush_wbuf(chmp, WBUF_NOPAD);
 188                         if (ret)
 189                                 goto outerr;
 190                 }
 191         }
 192
 193         for (invec = 0; invec < count; invec++) {
 194                 int vlen = invecs[invec].iov_len;
 195                 u_char* v = invecs[invec].iov_base;
 196
 197                 /* fill the whole wbuf */
 198                 wbuf_retlen = chfs_fill_wbuf(chmp, v, vlen);
 199                 if (chmp->chm_wbuf_len == chmp->chm_wbuf_pagesize) {
 200                         ret = chfs_flush_wbuf(chmp, WBUF_NOPAD);
 201                         if (ret) {
 202                                 goto outerr;
 203                         }
 204                 }
 205
 206                 vlen -= wbuf_retlen;
 207                 outvec_to += wbuf_retlen;
 208                 v += wbuf_retlen;
 209                 donelen += wbuf_retlen;
 210
 211                 /* if there is more residual data than the length of the wbuf
 212                  * write it out directly until it's fit in the wbuf */
 213                 if (vlen >= chmp->chm_wbuf_pagesize) {
 214                         ret = chfs_write_leb(chmp, lnr, v, outvec_to, PAGE_DIV(vlen), &wbuf_retlen);
 215                         vlen -= wbuf_retlen;
 216                         outvec_to += wbuf_retlen;
 217                         chmp->chm_wbuf_ofs = outvec_to;
 218                         v += wbuf_retlen;
 219                         donelen += wbuf_retlen;
 220                 }
 221
 222                 /* write the residual data to the wbuf */
 223                 wbuf_retlen = chfs_fill_wbuf(chmp, v, vlen);
 224                 if (chmp->chm_wbuf_len == chmp->chm_wbuf_pagesize) {
 225                         ret = chfs_flush_wbuf(chmp, WBUF_NOPAD);
 226                         if (ret)
 227                                 goto outerr;
 228                 }
 229
 230                 outvec_to += wbuf_retlen;
 231                 donelen += wbuf_retlen;
 232         }
 233         *retlen = donelen;
 234         rw_exit(&chmp->chm_lock_wbuf);
 235         return ret;
 236
 237 outerr:
 238         *retlen = 0;
 239         return ret;
 240 }
 241
 242 /*
 243  * chfs_flush_peding_wbuf - write wbuf to the flash
 244  * Used when we must flush wbuf right now.
 245  * If wbuf has free space, pad it to the size of wbuf and write out.
 246  */
 247 int chfs_flush_pending_wbuf(struct chfs_mount *chmp)
 248 {
 249         int err;
 250         KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
 251         mutex_enter(&chmp->chm_lock_sizes);
 252         rw_enter(&chmp->chm_lock_wbuf, RW_WRITER);
 253         err = chfs_flush_wbuf(chmp, WBUF_SETPAD);
 254         rw_exit(&chmp->chm_lock_wbuf);
 255         mutex_exit(&chmp->chm_lock_sizes);
 256         return err;
 257 }