module/os/freebsd/zfs/dmu_os.c

   1 /*
   2  * Copyright (c) 2020 iXsystems, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  */
  27
  28 #include <sys/types.h>
  29 #include <sys/param.h>
  30 #include <sys/dmu.h>
  31 #include <sys/dmu_impl.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/dbuf.h>
  34 #include <sys/dnode.h>
  35 #include <sys/zfs_context.h>
  36 #include <sys/dmu_objset.h>
  37 #include <sys/dmu_traverse.h>
  38 #include <sys/dsl_dataset.h>
  39 #include <sys/dsl_dir.h>
  40 #include <sys/dsl_pool.h>
  41 #include <sys/dsl_synctask.h>
  42 #include <sys/dsl_prop.h>
  43 #include <sys/dmu_zfetch.h>
  44 #include <sys/zfs_ioctl.h>
  45 #include <sys/zap.h>
  46 #include <sys/zio_checksum.h>
  47 #include <sys/zio_compress.h>
  48 #include <sys/sa.h>
  49 #include <sys/zfeature.h>
  50 #include <sys/abd.h>
  51 #include <sys/zfs_rlock.h>
  52 #include <sys/racct.h>
  53 #include <sys/vm.h>
  54 #include <sys/zfs_znode.h>
  55 #include <sys/zfs_vnops.h>
  56
  57 #include <sys/ccompat.h>
  58
  59 #ifndef IDX_TO_OFF
  60 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
  61 #endif
  62
  63 #define VM_ALLOC_BUSY_FLAGS  VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY
  64
  65 int
  66 dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
  67     vm_page_t *ma, dmu_tx_t *tx)
  68 {
  69         dmu_buf_t **dbp;
  70         struct sf_buf *sf;
  71         int numbufs, i;
  72         int err;
  73
  74         if (size == 0)
  75                 return (0);
  76
  77         err = dmu_buf_hold_array(os, object, offset, size,
  78             FALSE, FTAG, &numbufs, &dbp);
  79         if (err)
  80                 return (err);
  81
  82         for (i = 0; i < numbufs; i++) {
  83                 int tocpy, copied, thiscpy;
  84                 int bufoff;
  85                 dmu_buf_t *db = dbp[i];
  86                 caddr_t va;
  87
  88                 ASSERT3U(size, >, 0);
  89                 ASSERT3U(db->db_size, >=, PAGESIZE);
  90
  91                 bufoff = offset - db->db_offset;
  92                 tocpy = (int)MIN(db->db_size - bufoff, size);
  93
  94                 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
  95
  96                 if (tocpy == db->db_size)
  97                         dmu_buf_will_fill(db, tx, B_FALSE);
  98                 else
  99                         dmu_buf_will_dirty(db, tx);
 100
 101                 for (copied = 0; copied < tocpy; copied += PAGESIZE) {
 102                         ASSERT3U(ptoa((*ma)->pindex), ==,
 103                             db->db_offset + bufoff);
 104                         thiscpy = MIN(PAGESIZE, tocpy - copied);
 105                         va = zfs_map_page(*ma, &sf);
 106                         memcpy((char *)db->db_data + bufoff, va, thiscpy);
 107                         zfs_unmap_page(sf);
 108                         ma += 1;
 109                         bufoff += PAGESIZE;
 110                 }
 111
 112                 if (tocpy == db->db_size)
 113                         dmu_buf_fill_done(db, tx, B_FALSE);
 114
 115                 offset += tocpy;
 116                 size -= tocpy;
 117         }
 118         dmu_buf_rele_array(dbp, numbufs, FTAG);
 119         return (err);
 120 }
 121
 122 int
 123 dmu_read_pages(objset_t *os, uint64_t object, vm_page_t *ma, int count,
 124     int *rbehind, int *rahead, int last_size)
 125 {
 126         struct sf_buf *sf;
 127         vm_object_t vmobj;
 128         vm_page_t m;
 129         dmu_buf_t **dbp;
 130         dmu_buf_t *db;
 131         caddr_t va;
 132         int numbufs, i;
 133         int bufoff, pgoff, tocpy;
 134         int mi, di;
 135         int err;
 136
 137         ASSERT3U(ma[0]->pindex + count - 1, ==, ma[count - 1]->pindex);
 138         ASSERT3S(last_size, <=, PAGE_SIZE);
 139
 140         err = dmu_buf_hold_array(os, object, IDX_TO_OFF(ma[0]->pindex),
 141             IDX_TO_OFF(count - 1) + last_size, TRUE, FTAG, &numbufs, &dbp);
 142         if (err != 0)
 143                 return (err);
 144
 145 #ifdef ZFS_DEBUG
 146         IMPLY(last_size < PAGE_SIZE, *rahead == 0);
 147         if (dbp[0]->db_offset != 0 || numbufs > 1) {
 148                 for (i = 0; i < numbufs; i++) {
 149                         ASSERT(ISP2(dbp[i]->db_size));
 150                         ASSERT3U((dbp[i]->db_offset % dbp[i]->db_size), ==, 0);
 151                         ASSERT3U(dbp[i]->db_size, ==, dbp[0]->db_size);
 152                 }
 153         }
 154 #endif
 155
 156         vmobj = ma[0]->object;
 157
 158         db = dbp[0];
 159         for (i = 0; i < *rbehind; i++) {
 160                 m = vm_page_grab_unlocked(vmobj, ma[0]->pindex - 1 - i,
 161                     VM_ALLOC_NORMAL | VM_ALLOC_NOWAIT | VM_ALLOC_BUSY_FLAGS);
 162                 if (m == NULL)
 163                         break;
 164                 if (!vm_page_none_valid(m)) {
 165                         ASSERT3U(m->valid, ==, VM_PAGE_BITS_ALL);
 166                         vm_page_sunbusy(m);
 167                         break;
 168                 }
 169                 ASSERT3U(m->dirty, ==, 0);
 170                 ASSERT(!pmap_page_is_write_mapped(m));
 171
 172                 ASSERT3U(db->db_size, >, PAGE_SIZE);
 173                 bufoff = IDX_TO_OFF(m->pindex) % db->db_size;
 174                 va = zfs_map_page(m, &sf);
 175                 memcpy(va, (char *)db->db_data + bufoff, PAGESIZE);
 176                 zfs_unmap_page(sf);
 177                 vm_page_valid(m);
 178                 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
 179                         vm_page_activate(m);
 180                 else
 181                         vm_page_deactivate(m);
 182                 vm_page_sunbusy(m);
 183         }
 184         *rbehind = i;
 185
 186         bufoff = IDX_TO_OFF(ma[0]->pindex) % db->db_size;
 187         pgoff = 0;
 188         for (mi = 0, di = 0; mi < count && di < numbufs; ) {
 189                 if (pgoff == 0) {
 190                         m = ma[mi];
 191                         if (m != bogus_page) {
 192                                 vm_page_assert_xbusied(m);
 193                                 ASSERT(vm_page_none_valid(m));
 194                                 ASSERT3U(m->dirty, ==, 0);
 195                                 ASSERT(!pmap_page_is_write_mapped(m));
 196                                 va = zfs_map_page(m, &sf);
 197                         }
 198                 }
 199                 if (bufoff == 0)
 200                         db = dbp[di];
 201
 202                 if (m != bogus_page) {
 203                         ASSERT3U(IDX_TO_OFF(m->pindex) + pgoff, ==,
 204                             db->db_offset + bufoff);
 205                 }
 206
 207                 /*
 208                  * We do not need to clamp the copy size by the file
 209                  * size as the last block is zero-filled beyond the
 210                  * end of file anyway.
 211                  */
 212                 tocpy = MIN(db->db_size - bufoff, PAGESIZE - pgoff);
 213                 ASSERT3S(tocpy, >=, 0);
 214                 if (m != bogus_page)
 215                         memcpy(va + pgoff, (char *)db->db_data + bufoff, tocpy);
 216
 217                 pgoff += tocpy;
 218                 ASSERT3S(pgoff, >=, 0);
 219                 ASSERT3S(pgoff, <=, PAGESIZE);
 220                 if (pgoff == PAGESIZE) {
 221                         if (m != bogus_page) {
 222                                 zfs_unmap_page(sf);
 223                                 vm_page_valid(m);
 224                         }
 225                         ASSERT3S(mi, <, count);
 226                         mi++;
 227                         pgoff = 0;
 228                 }
 229
 230                 bufoff += tocpy;
 231                 ASSERT3S(bufoff, >=, 0);
 232                 ASSERT3S(bufoff, <=, db->db_size);
 233                 if (bufoff == db->db_size) {
 234                         ASSERT3S(di, <, numbufs);
 235                         di++;
 236                         bufoff = 0;
 237                 }
 238         }
 239
 240 #ifdef ZFS_DEBUG
 241         /*
 242          * Three possibilities:
 243          * - last requested page ends at a buffer boundary and , thus,
 244          *   all pages and buffers have been iterated;
 245          * - all requested pages are filled, but the last buffer
 246          *   has not been exhausted;
 247          *   the read-ahead is possible only in this case;
 248          * - all buffers have been read, but the last page has not been
 249          *   fully filled;
 250          *   this is only possible if the file has only a single buffer
 251          *   with a size that is not a multiple of the page size.
 252          */
 253         if (mi == count) {
 254                 ASSERT3S(di, >=, numbufs - 1);
 255                 IMPLY(*rahead != 0, di == numbufs - 1);
 256                 IMPLY(*rahead != 0, bufoff != 0);
 257                 ASSERT0(pgoff);
 258         }
 259         if (di == numbufs) {
 260                 ASSERT3S(mi, >=, count - 1);
 261                 ASSERT0(*rahead);
 262                 IMPLY(pgoff == 0, mi == count);
 263                 if (pgoff != 0) {
 264                         ASSERT3S(mi, ==, count - 1);
 265                         ASSERT3U((dbp[0]->db_size & PAGE_MASK), !=, 0);
 266                 }
 267         }
 268 #endif
 269         if (pgoff != 0) {
 270                 ASSERT3P(m, !=, bogus_page);
 271                 memset(va + pgoff, 0, PAGESIZE - pgoff);
 272                 zfs_unmap_page(sf);
 273                 vm_page_valid(m);
 274         }
 275
 276         for (i = 0; i < *rahead; i++) {
 277                 m = vm_page_grab_unlocked(vmobj, ma[count - 1]->pindex + 1 + i,
 278                     VM_ALLOC_NORMAL | VM_ALLOC_NOWAIT | VM_ALLOC_BUSY_FLAGS);
 279                 if (m == NULL)
 280                         break;
 281                 if (!vm_page_none_valid(m)) {
 282                         ASSERT3U(m->valid, ==, VM_PAGE_BITS_ALL);
 283                         vm_page_sunbusy(m);
 284                         break;
 285                 }
 286                 ASSERT3U(m->dirty, ==, 0);
 287                 ASSERT(!pmap_page_is_write_mapped(m));
 288
 289                 ASSERT3U(db->db_size, >, PAGE_SIZE);
 290                 bufoff = IDX_TO_OFF(m->pindex) % db->db_size;
 291                 tocpy = MIN(db->db_size - bufoff, PAGESIZE);
 292                 va = zfs_map_page(m, &sf);
 293                 memcpy(va, (char *)db->db_data + bufoff, tocpy);
 294                 if (tocpy < PAGESIZE) {
 295                         ASSERT3S(i, ==, *rahead - 1);
 296                         ASSERT3U((db->db_size & PAGE_MASK), !=, 0);
 297                         memset(va + tocpy, 0, PAGESIZE - tocpy);
 298                 }
 299                 zfs_unmap_page(sf);
 300                 vm_page_valid(m);
 301                 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
 302                         vm_page_activate(m);
 303                 else
 304                         vm_page_deactivate(m);
 305                 vm_page_sunbusy(m);
 306         }
 307         *rahead = i;
 308
 309         dmu_buf_rele_array(dbp, numbufs, FTAG);
 310         return (0);
 311 }