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ffs_balloc.c

/*    $OpenBSD: ffs_balloc.c,v 1.24 2003/06/02 23:28:22 millert Exp $   */
/*    $NetBSD: ffs_balloc.c,v 1.3 1996/02/09 22:22:21 christos Exp $    */

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *    @(#)ffs_balloc.c  8.4 (Berkeley) 9/23/93
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/vnode.h>

#include <uvm/uvm_extern.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

/*
 * Balloc defines the structure of file system storage
 * by allocating the physical blocks on a device given
 * the inode and the logical block number in a file.
 */
int
ffs_balloc(struct inode *ip, off_t startoffset, int size, struct ucred *cred,
    int flags, struct buf **bpp)
{
      daddr_t lbn;
      struct fs *fs;
      daddr_t nb;
      struct buf *bp, *nbp;
      struct vnode *vp;
      struct indir indirs[NIADDR + 2];
      daddr_t newb, *bap, pref;
      int deallocated, osize, nsize, num, i, error;
      daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR+1];
      int unwindidx = -1;

      vp = ITOV(ip);
      fs = ip->i_fs;
      lbn = lblkno(fs, startoffset);
      size = blkoff(fs, startoffset) + size;
      if (size > fs->fs_bsize)
            panic("ffs_balloc: blk too big");
      if (bpp != NULL)
            *bpp = NULL;
      if (lbn < 0)
            return (EFBIG);

      /*
       * If the next write will extend the file into a new block,
       * and the file is currently composed of a fragment
       * this fragment has to be extended to be a full block.
       */
      nb = lblkno(fs, ip->i_ffs_size);
      if (nb < NDADDR && nb < lbn) {
            osize = blksize(fs, ip, nb);
            if (osize < fs->fs_bsize && osize > 0) {
                  error = ffs_realloccg(ip, nb,
                      ffs_blkpref(ip, nb, (int)nb, &ip->i_ffs_db[0]),
                      osize, (int)fs->fs_bsize, cred, bpp, &newb);
                  if (error)
                        return (error);
                  if (DOINGSOFTDEP(vp))
                        softdep_setup_allocdirect(ip, nb, newb,
                            ip->i_ffs_db[nb], fs->fs_bsize, osize,
                            bpp ? *bpp : NULL);

                  ip->i_ffs_size = lblktosize(fs, nb + 1);
                  uvm_vnp_setsize(vp, ip->i_ffs_size);
                  ip->i_ffs_db[nb] = newb;
                  ip->i_flag |= IN_CHANGE | IN_UPDATE;
                  if (bpp != NULL) {
                        if (flags & B_SYNC)
                              bwrite(*bpp);
                        else
                              bawrite(*bpp);
                  }
            }
      }
      /*
       * The first NDADDR blocks are direct blocks
       */
      if (lbn < NDADDR) {
            nb = ip->i_ffs_db[lbn];
            if (nb != 0 && ip->i_ffs_size >= lblktosize(fs, lbn + 1)) {
                  /*
                   * The block is an already-allocated direct block
                   * and the file already extends past this block,
                   * thus this must be a whole block.
                   * Just read the block (if requested).
                   */

                  if (bpp != NULL) {
                        error = bread(vp, lbn, fs->fs_bsize, NOCRED,
                            bpp);
                        if (error) {
                              brelse(*bpp);
                              return (error);
                        }
                  }
                  return (0);
            }
            if (nb != 0) {
                  /*
                   * Consider need to reallocate a fragment.
                   */
                  osize = fragroundup(fs, blkoff(fs, ip->i_ffs_size));
                  nsize = fragroundup(fs, size);
                  if (nsize <= osize) {
                        /*
                         * The existing block is already
                         * at least as big as we want.
                         * Just read the block (if requested).
                         */
                        if (bpp != NULL) {
                              error = bread(vp, lbn, osize, NOCRED,
                                  bpp);
                              if (error) {
                                    brelse(*bpp);
                                    return (error);
                              }
                        }
                        return (0);
                  } else {
                        /*
                         * The existing block is smaller than we
                         * want, grow it.
                         */
                        error = ffs_realloccg(ip, lbn,
                            ffs_blkpref(ip, lbn, (int)lbn,
                              &ip->i_ffs_db[0]),
                            osize, nsize, cred, bpp, &newb);
                        if (error)
                              return (error);
                        if (DOINGSOFTDEP(vp))
                              softdep_setup_allocdirect(ip, lbn,
                                  newb, nb, nsize, osize,
                                  bpp ? *bpp : NULL);
                  }
            } else {
                  /*
                   * The block was not previously allocated,
                   * allocate a new block or fragment.
                   */

                  if (ip->i_ffs_size < lblktosize(fs, lbn + 1))
                        nsize = fragroundup(fs, size);
                  else
                        nsize = fs->fs_bsize;
                  error = ffs_alloc(ip, lbn,
                      ffs_blkpref(ip, lbn, (int)lbn, &ip->i_ffs_db[0]),
                      nsize, cred, &newb);
                  if (error)
                        return (error);
                  if (bpp != NULL) {
                        *bpp = getblk(vp, lbn, nsize, 0, 0);
                        (*bpp)->b_blkno = fsbtodb(fs, newb);
                        if (flags & B_CLRBUF)
                              clrbuf(*bpp);
                  }
                  if (DOINGSOFTDEP(vp))
                        softdep_setup_allocdirect(ip, lbn, newb, 0,
                            nsize, 0, bpp ? *bpp : NULL);
            }
            ip->i_ffs_db[lbn] = newb;
            ip->i_flag |= IN_CHANGE | IN_UPDATE;
            return (0);
      }

      /*
       * Determine the number of levels of indirection.
       */
      pref = 0;
      if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
            return(error);
#ifdef DIAGNOSTIC
      if (num < 1)
            panic ("ffs_balloc: ufs_bmaparray returned indirect block");
#endif
      /*
       * Fetch the first indirect block allocating if necessary.
       */
      --num;
      nb = ip->i_ffs_ib[indirs[0].in_off];

      allocib = NULL;
      allocblk = allociblk;
      if (nb == 0) {
            pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
              error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                          cred, &newb);
            if (error)
                  goto fail;
            nb = newb;

            *allocblk++ = nb;
            bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
            bp->b_blkno = fsbtodb(fs, nb);
            clrbuf(bp);

            if (DOINGSOFTDEP(vp)) {
                  softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off,
                      newb, 0, fs->fs_bsize, 0, bp);
                  bdwrite(bp);
            } else {
                  /*
                   * Write synchronously so that indirect blocks
                   * never point at garbage.
                   */
                  if ((error = bwrite(bp)) != 0)
                        goto fail;
            }
            allocib = &ip->i_ffs_ib[indirs[0].in_off];
            *allocib = nb;
            ip->i_flag |= IN_CHANGE | IN_UPDATE;
      }

      /*
       * Fetch through the indirect blocks, allocating as necessary.
       */
      for (i = 1;;) {
            error = bread(vp,
                indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
            if (error) {
                  brelse(bp);
                  goto fail;
            }
            bap = (daddr_t *)bp->b_data;
            nb = bap[indirs[i].in_off];
            if (i == num)
                  break;
            i++;
            if (nb != 0) {
                  brelse(bp);
                  continue;
            }
            if (pref == 0)
                  pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
            error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred,
                          &newb);
            if (error) {
                  brelse(bp);
                  goto fail;
            }
            nb = newb;
            *allocblk++ = nb;
            nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
            nbp->b_blkno = fsbtodb(fs, nb);
            clrbuf(nbp);

            if (DOINGSOFTDEP(vp)) {
                  softdep_setup_allocindir_meta(nbp, ip, bp,
                      indirs[i - 1].in_off, nb);
                  bdwrite(nbp);
            } else {
                  /*
                   * Write synchronously so that indirect blocks
                   * never point at garbage.
                   */
                  if ((error = bwrite(nbp)) != 0) {
                        brelse(bp);
                        goto fail;
                  }
            }
            bap[indirs[i - 1].in_off] = nb;
            if (allocib == NULL && unwindidx < 0)
                  unwindidx = i - 1;
            /*
             * If required, write synchronously, otherwise use
             * delayed write.
             */
            if (flags & B_SYNC) {
                  bwrite(bp);
            } else {
                  bdwrite(bp);
            }
      }
      /*
       * Get the data block, allocating if necessary.
       */
      if (nb == 0) {
            pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
            error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred,
                          &newb);
            if (error) {
                  brelse(bp);
                  goto fail;
            }
            nb = newb;
            *allocblk++ = nb;
            if (bpp != NULL) {
                  nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
                  nbp->b_blkno = fsbtodb(fs, nb);
                  if (flags & B_CLRBUF)
                        clrbuf(nbp);
                  *bpp = nbp;
            }
            if (DOINGSOFTDEP(vp))
                  softdep_setup_allocindir_page(ip, lbn, bp,
                      indirs[i].in_off, nb, 0, bpp ? *bpp : NULL);
            bap[indirs[i].in_off] = nb;
            /*
             * If required, write synchronously, otherwise use
             * delayed write.
             */
            if (flags & B_SYNC) {
                  bwrite(bp);
            } else {
                  bdwrite(bp);
            }
            return (0);
      }
      brelse(bp);
      if (bpp != NULL) {
            if (flags & B_CLRBUF) {
                  error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
                  if (error) {
                        brelse(nbp);
                        goto fail;
                  }
            } else {
                  nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
                  nbp->b_blkno = fsbtodb(fs, nb);
            }
            *bpp = nbp;
      }
      return (0);

fail:
      /*
       * If we have failed part way through block allocation, we
       * have to deallocate any indirect blocks that we have allocated.
       */
      for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
            ffs_blkfree(ip, *blkp, fs->fs_bsize);
            deallocated += fs->fs_bsize;
      }
      if (allocib != NULL) {
            *allocib = 0;
      } else if (unwindidx >= 0) {
            int r;

            r = bread(vp, indirs[unwindidx].in_lbn, 
                (int)fs->fs_bsize, NOCRED, &bp);
            if (r)
                  panic("Could not unwind indirect block, error %d", r);
            bap = (daddr_t *)bp->b_data;
            bap[indirs[unwindidx].in_off] = 0;
            if (flags & B_SYNC) {
                  bwrite(bp);
            } else {
                  bdwrite(bp);
            }
      }
      if (deallocated) {
            /*
             * Restore user's disk quota because allocation failed.
             */
            (void)ufs_quota_free_blocks(ip, btodb(deallocated), cred);

            ip->i_ffs_blocks -= btodb(deallocated);
            ip->i_flag |= IN_CHANGE | IN_UPDATE;
      }

      return (error);
}

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