sys/ufs/lfs/ulfs_readwrite.c

   1 /*      $NetBSD: ulfs_readwrite.c,v 1.7 2013/10/17 21:01:08 christos Exp $      */
   2 /*  from NetBSD: ufs_readwrite.c,v 1.105 2013/01/22 09:39:18 dholland Exp  */
   3
   4 /*-
   5  * Copyright (c) 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      @(#)ufs_readwrite.c     8.11 (Berkeley) 5/8/95
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __KERNEL_RCSID(1, "$NetBSD: ulfs_readwrite.c,v 1.7 2013/10/17 21:01:08 christos Exp $");
  37
  38 #ifdef LFS_READWRITE
  39 #define FS                      struct lfs
  40 #define I_FS                    i_lfs
  41 #define READ                    lfs_read
  42 #define READ_S                  "lfs_read"
  43 #define WRITE                   lfs_write
  44 #define WRITE_S                 "lfs_write"
  45 #define fs_bsize                lfs_bsize
  46 #define fs_bmask                lfs_bmask
  47 #else
  48 #define FS                      struct fs
  49 #define I_FS                    i_fs
  50 #define READ                    ffs_read
  51 #define READ_S                  "ffs_read"
  52 #define WRITE                   ffs_write
  53 #define WRITE_S                 "ffs_write"
  54 #endif
  55
  56 /*
  57  * Vnode op for reading.
  58  */
  59 /* ARGSUSED */
  60 int
  61 READ(void *v)
  62 {
  63         struct vop_read_args /* {
  64                 struct vnode *a_vp;
  65                 struct uio *a_uio;
  66                 int a_ioflag;
  67                 kauth_cred_t a_cred;
  68         } */ *ap = v;
  69         struct vnode *vp;
  70         struct inode *ip;
  71         struct uio *uio;
  72         struct buf *bp;
  73         FS *fs;
  74         vsize_t bytelen;
  75         daddr_t lbn, nextlbn;
  76         off_t bytesinfile;
  77         long size, xfersize, blkoffset;
  78         int error, ioflag;
  79         bool usepc = false;
  80
  81         vp = ap->a_vp;
  82         ip = VTOI(vp);
  83         fs = ip->I_FS;
  84         uio = ap->a_uio;
  85         ioflag = ap->a_ioflag;
  86         error = 0;
  87
  88 #ifdef DIAGNOSTIC
  89         if (uio->uio_rw != UIO_READ)
  90                 panic("%s: mode", READ_S);
  91
  92         if (vp->v_type == VLNK) {
  93                 if (ip->i_size < fs->um_maxsymlinklen ||
  94                     (fs->um_maxsymlinklen == 0 && DIP(ip, blocks) == 0))
  95                         panic("%s: short symlink", READ_S);
  96         } else if (vp->v_type != VREG && vp->v_type != VDIR)
  97                 panic("%s: type %d", READ_S, vp->v_type);
  98 #endif
  99         if ((u_int64_t)uio->uio_offset > fs->um_maxfilesize)
 100                 return (EFBIG);
 101         if (uio->uio_resid == 0)
 102                 return (0);
 103
 104 #ifndef LFS_READWRITE
 105         if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) == SF_SNAPSHOT)
 106                 return ffs_snapshot_read(vp, uio, ioflag);
 107 #endif /* !LFS_READWRITE */
 108
 109         fstrans_start(vp->v_mount, FSTRANS_SHARED);
 110
 111         if (uio->uio_offset >= ip->i_size)
 112                 goto out;
 113
 114 #ifdef LFS_READWRITE
 115         usepc = (vp->v_type == VREG && ip->i_number != LFS_IFILE_INUM);
 116 #else /* !LFS_READWRITE */
 117         usepc = vp->v_type == VREG;
 118 #endif /* !LFS_READWRITE */
 119         if (usepc) {
 120                 const int advice = IO_ADV_DECODE(ap->a_ioflag);
 121
 122                 while (uio->uio_resid > 0) {
 123                         if (ioflag & IO_DIRECT) {
 124                                 genfs_directio(vp, uio, ioflag);
 125                         }
 126                         bytelen = MIN(ip->i_size - uio->uio_offset,
 127                             uio->uio_resid);
 128                         if (bytelen == 0)
 129                                 break;
 130                         error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice,
 131                             UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp));
 132                         if (error)
 133                                 break;
 134                 }
 135                 goto out;
 136         }
 137
 138         for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
 139                 bytesinfile = ip->i_size - uio->uio_offset;
 140                 if (bytesinfile <= 0)
 141                         break;
 142                 lbn = lfs_lblkno(fs, uio->uio_offset);
 143                 nextlbn = lbn + 1;
 144                 size = lfs_blksize(fs, ip, lbn);
 145                 blkoffset = lfs_blkoff(fs, uio->uio_offset);
 146                 xfersize = MIN(MIN(fs->fs_bsize - blkoffset, uio->uio_resid),
 147                     bytesinfile);
 148
 149                 if (lfs_lblktosize(fs, nextlbn) >= ip->i_size)
 150                         error = bread(vp, lbn, size, NOCRED, 0, &bp);
 151                 else {
 152                         int nextsize = lfs_blksize(fs, ip, nextlbn);
 153                         error = breadn(vp, lbn,
 154                             size, &nextlbn, &nextsize, 1, NOCRED, 0, &bp);
 155                 }
 156                 if (error)
 157                         break;
 158
 159                 /*
 160                  * We should only get non-zero b_resid when an I/O error
 161                  * has occurred, which should cause us to break above.
 162                  * However, if the short read did not cause an error,
 163                  * then we want to ensure that we do not uiomove bad
 164                  * or uninitialized data.
 165                  */
 166                 size -= bp->b_resid;
 167                 if (size < xfersize) {
 168                         if (size == 0)
 169                                 break;
 170                         xfersize = size;
 171                 }
 172                 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
 173                 if (error)
 174                         break;
 175                 brelse(bp, 0);
 176         }
 177         if (bp != NULL)
 178                 brelse(bp, 0);
 179
 180  out:
 181         if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) {
 182                 ip->i_flag |= IN_ACCESS;
 183                 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) {
 184                         error = lfs_update(vp, NULL, NULL, UPDATE_WAIT);
 185                 }
 186         }
 187
 188         fstrans_done(vp->v_mount);
 189         return (error);
 190 }
 191
 192 /*
 193  * Vnode op for writing.
 194  */
 195 int
 196 WRITE(void *v)
 197 {
 198         struct vop_write_args /* {
 199                 struct vnode *a_vp;
 200                 struct uio *a_uio;
 201                 int a_ioflag;
 202                 kauth_cred_t a_cred;
 203         } */ *ap = v;
 204         struct vnode *vp;
 205         struct uio *uio;
 206         struct inode *ip;
 207         FS *fs;
 208         struct buf *bp;
 209         kauth_cred_t cred;
 210         daddr_t lbn;
 211         off_t osize, origoff, oldoff, preallocoff, endallocoff, nsize;
 212         int blkoffset, error, flags, ioflag, resid, size, xfersize;
 213         int aflag;
 214         int extended=0;
 215         vsize_t bytelen;
 216         bool async;
 217         bool usepc = false;
 218 #ifdef LFS_READWRITE
 219         bool need_unreserve = false;
 220 #endif
 221
 222         cred = ap->a_cred;
 223         ioflag = ap->a_ioflag;
 224         uio = ap->a_uio;
 225         vp = ap->a_vp;
 226         ip = VTOI(vp);
 227
 228         KASSERT(vp->v_size == ip->i_size);
 229 #ifdef DIAGNOSTIC
 230         if (uio->uio_rw != UIO_WRITE)
 231                 panic("%s: mode", WRITE_S);
 232 #endif
 233
 234         switch (vp->v_type) {
 235         case VREG:
 236                 if (ioflag & IO_APPEND)
 237                         uio->uio_offset = ip->i_size;
 238                 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
 239                         return (EPERM);
 240                 /* FALLTHROUGH */
 241         case VLNK:
 242                 break;
 243         case VDIR:
 244                 if ((ioflag & IO_SYNC) == 0)
 245                         panic("%s: nonsync dir write", WRITE_S);
 246                 break;
 247         default:
 248                 panic("%s: type", WRITE_S);
 249         }
 250
 251         fs = ip->I_FS;
 252         if (uio->uio_offset < 0 ||
 253             (u_int64_t)uio->uio_offset + uio->uio_resid > fs->um_maxfilesize)
 254                 return (EFBIG);
 255 #ifdef LFS_READWRITE
 256         /* Disallow writes to the Ifile, even if noschg flag is removed */
 257         /* XXX can this go away when the Ifile is no longer in the namespace? */
 258         if (vp == fs->lfs_ivnode)
 259                 return (EPERM);
 260 #endif
 261         if (uio->uio_resid == 0)
 262                 return (0);
 263
 264         fstrans_start(vp->v_mount, FSTRANS_SHARED);
 265
 266         flags = ioflag & IO_SYNC ? B_SYNC : 0;
 267         async = vp->v_mount->mnt_flag & MNT_ASYNC;
 268         origoff = uio->uio_offset;
 269         resid = uio->uio_resid;
 270         osize = ip->i_size;
 271         error = 0;
 272
 273         usepc = vp->v_type == VREG;
 274
 275 #ifdef LFS_READWRITE
 276         async = true;
 277         lfs_availwait(fs, lfs_btofsb(fs, uio->uio_resid));
 278         lfs_check(vp, LFS_UNUSED_LBN, 0);
 279 #endif /* !LFS_READWRITE */
 280         if (!usepc)
 281                 goto bcache;
 282
 283         preallocoff = round_page(lfs_blkroundup(fs, MAX(osize, uio->uio_offset)));
 284         aflag = ioflag & IO_SYNC ? B_SYNC : 0;
 285         nsize = MAX(osize, uio->uio_offset + uio->uio_resid);
 286         endallocoff = nsize - lfs_blkoff(fs, nsize);
 287
 288         /*
 289          * if we're increasing the file size, deal with expanding
 290          * the fragment if there is one.
 291          */
 292
 293         if (nsize > osize && lfs_lblkno(fs, osize) < ULFS_NDADDR &&
 294             lfs_lblkno(fs, osize) != lfs_lblkno(fs, nsize) &&
 295             lfs_blkroundup(fs, osize) != osize) {
 296                 off_t eob;
 297
 298                 eob = lfs_blkroundup(fs, osize);
 299                 uvm_vnp_setwritesize(vp, eob);
 300                 error = ulfs_balloc_range(vp, osize, eob - osize, cred, aflag);
 301                 if (error)
 302                         goto out;
 303                 if (flags & B_SYNC) {
 304                         mutex_enter(vp->v_interlock);
 305                         VOP_PUTPAGES(vp, trunc_page(osize & fs->fs_bmask),
 306                             round_page(eob),
 307                             PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED);
 308                 }
 309         }
 310
 311         while (uio->uio_resid > 0) {
 312                 int ubc_flags = UBC_WRITE;
 313                 bool overwrite; /* if we're overwrite a whole block */
 314                 off_t newoff;
 315
 316                 if (ioflag & IO_DIRECT) {
 317                         genfs_directio(vp, uio, ioflag | IO_JOURNALLOCKED);
 318                 }
 319
 320                 oldoff = uio->uio_offset;
 321                 blkoffset = lfs_blkoff(fs, uio->uio_offset);
 322                 bytelen = MIN(fs->fs_bsize - blkoffset, uio->uio_resid);
 323                 if (bytelen == 0) {
 324                         break;
 325                 }
 326
 327                 /*
 328                  * if we're filling in a hole, allocate the blocks now and
 329                  * initialize the pages first.  if we're extending the file,
 330                  * we can safely allocate blocks without initializing pages
 331                  * since the new blocks will be inaccessible until the write
 332                  * is complete.
 333                  */
 334                 overwrite = uio->uio_offset >= preallocoff &&
 335                     uio->uio_offset < endallocoff;
 336                 if (!overwrite && (vp->v_vflag & VV_MAPPED) == 0 &&
 337                     lfs_blkoff(fs, uio->uio_offset) == 0 &&
 338                     (uio->uio_offset & PAGE_MASK) == 0) {
 339                         vsize_t len;
 340
 341                         len = trunc_page(bytelen);
 342                         len -= lfs_blkoff(fs, len);
 343                         if (len > 0) {
 344                                 overwrite = true;
 345                                 bytelen = len;
 346                         }
 347                 }
 348
 349                 newoff = oldoff + bytelen;
 350                 if (vp->v_size < newoff) {
 351                         uvm_vnp_setwritesize(vp, newoff);
 352                 }
 353
 354                 if (!overwrite) {
 355                         error = ulfs_balloc_range(vp, uio->uio_offset, bytelen,
 356                             cred, aflag);
 357                         if (error)
 358                                 break;
 359                 } else {
 360                         genfs_node_wrlock(vp);
 361                         error = GOP_ALLOC(vp, uio->uio_offset, bytelen,
 362                             aflag, cred);
 363                         genfs_node_unlock(vp);
 364                         if (error)
 365                                 break;
 366                         ubc_flags |= UBC_FAULTBUSY;
 367                 }
 368
 369                 /*
 370                  * copy the data.
 371                  */
 372
 373                 error = ubc_uiomove(&vp->v_uobj, uio, bytelen,
 374                     IO_ADV_DECODE(ioflag), ubc_flags | UBC_UNMAP_FLAG(vp));
 375
 376                 /*
 377                  * update UVM's notion of the size now that we've
 378                  * copied the data into the vnode's pages.
 379                  *
 380                  * we should update the size even when uiomove failed.
 381                  */
 382
 383                 if (vp->v_size < newoff) {
 384                         uvm_vnp_setsize(vp, newoff);
 385                         extended = 1;
 386                 }
 387
 388                 if (error)
 389                         break;
 390
 391                 /*
 392                  * flush what we just wrote if necessary.
 393                  * XXXUBC simplistic async flushing.
 394                  */
 395
 396 #ifndef LFS_READWRITE
 397                 if (!async && oldoff >> 16 != uio->uio_offset >> 16) {
 398                         mutex_enter(vp->v_interlock);
 399                         error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16,
 400                             (uio->uio_offset >> 16) << 16,
 401                             PGO_CLEANIT | PGO_JOURNALLOCKED | PGO_LAZY);
 402                         if (error)
 403                                 break;
 404                 }
 405 #else
 406                 __USE(async);
 407 #endif
 408         }
 409         if (error == 0 && ioflag & IO_SYNC) {
 410                 mutex_enter(vp->v_interlock);
 411                 error = VOP_PUTPAGES(vp, trunc_page(origoff & fs->fs_bmask),
 412                     round_page(lfs_blkroundup(fs, uio->uio_offset)),
 413                     PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED);
 414         }
 415         goto out;
 416
 417  bcache:
 418         mutex_enter(vp->v_interlock);
 419         VOP_PUTPAGES(vp, trunc_page(origoff), round_page(origoff + resid),
 420             PGO_CLEANIT | PGO_FREE | PGO_SYNCIO | PGO_JOURNALLOCKED);
 421         while (uio->uio_resid > 0) {
 422                 lbn = lfs_lblkno(fs, uio->uio_offset);
 423                 blkoffset = lfs_blkoff(fs, uio->uio_offset);
 424                 xfersize = MIN(fs->fs_bsize - blkoffset, uio->uio_resid);
 425                 if (fs->fs_bsize > xfersize)
 426                         flags |= B_CLRBUF;
 427                 else
 428                         flags &= ~B_CLRBUF;
 429
 430 #ifdef LFS_READWRITE
 431                 error = lfs_reserve(fs, vp, NULL,
 432                     lfs_btofsb(fs, (ULFS_NIADDR + 1) << fs->lfs_bshift));
 433                 if (error)
 434                         break;
 435                 need_unreserve = true;
 436 #endif
 437                 error = lfs_balloc(vp, uio->uio_offset, xfersize,
 438                     ap->a_cred, flags, &bp);
 439
 440                 if (error)
 441                         break;
 442                 if (uio->uio_offset + xfersize > ip->i_size) {
 443                         ip->i_size = uio->uio_offset + xfersize;
 444                         DIP_ASSIGN(ip, size, ip->i_size);
 445                         uvm_vnp_setsize(vp, ip->i_size);
 446                         extended = 1;
 447                 }
 448                 size = lfs_blksize(fs, ip, lbn) - bp->b_resid;
 449                 if (xfersize > size)
 450                         xfersize = size;
 451
 452                 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
 453
 454                 /*
 455                  * if we didn't clear the block and the uiomove failed,
 456                  * the buf will now contain part of some other file,
 457                  * so we need to invalidate it.
 458                  */
 459                 if (error && (flags & B_CLRBUF) == 0) {
 460                         brelse(bp, BC_INVAL);
 461                         break;
 462                 }
 463 #ifdef LFS_READWRITE
 464                 (void)VOP_BWRITE(bp->b_vp, bp);
 465                 lfs_reserve(fs, vp, NULL,
 466                     -lfs_btofsb(fs, (ULFS_NIADDR + 1) << fs->lfs_bshift));
 467                 need_unreserve = false;
 468 #else
 469                 if (ioflag & IO_SYNC)
 470                         (void)bwrite(bp);
 471                 else if (xfersize + blkoffset == fs->fs_bsize)
 472                         bawrite(bp);
 473                 else
 474                         bdwrite(bp);
 475 #endif
 476                 if (error || xfersize == 0)
 477                         break;
 478         }
 479 #ifdef LFS_READWRITE
 480         if (need_unreserve) {
 481                 lfs_reserve(fs, vp, NULL,
 482                     -lfs_btofsb(fs, (ULFS_NIADDR + 1) << fs->lfs_bshift));
 483         }
 484 #endif
 485
 486         /*
 487          * If we successfully wrote any data, and we are not the superuser
 488          * we clear the setuid and setgid bits as a precaution against
 489          * tampering.
 490          */
 491 out:
 492         ip->i_flag |= IN_CHANGE | IN_UPDATE;
 493         if (vp->v_mount->mnt_flag & MNT_RELATIME)
 494                 ip->i_flag |= IN_ACCESS;
 495         if (resid > uio->uio_resid && ap->a_cred) {
 496                 if (ip->i_mode & ISUID) {
 497                         if (kauth_authorize_vnode(ap->a_cred,
 498                             KAUTH_VNODE_RETAIN_SUID, vp, NULL, EPERM) != 0) {
 499                                 ip->i_mode &= ~ISUID;
 500                                 DIP_ASSIGN(ip, mode, ip->i_mode);
 501                         }
 502                 }
 503
 504                 if (ip->i_mode & ISGID) {
 505                         if (kauth_authorize_vnode(ap->a_cred,
 506                             KAUTH_VNODE_RETAIN_SGID, vp, NULL, EPERM) != 0) {
 507                                 ip->i_mode &= ~ISGID;
 508                                 DIP_ASSIGN(ip, mode, ip->i_mode);
 509                         }
 510                 }
 511         }
 512         if (resid > uio->uio_resid)
 513                 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
 514         if (error) {
 515                 (void) lfs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred);
 516                 uio->uio_offset -= resid - uio->uio_resid;
 517                 uio->uio_resid = resid;
 518         } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) {
 519                 error = lfs_update(vp, NULL, NULL, UPDATE_WAIT);
 520         } else {
 521                 /* nothing */
 522         }
 523         KASSERT(vp->v_size == ip->i_size);
 524         fstrans_done(vp->v_mount);
 525
 526         return (error);
 527 }