コード例 #1
0
ファイル: ffs_balloc.c プロジェクト: kusumi/DragonFlyBSD
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		bwrite(bp);
		return (0);
	}
	brelse(bp);
	if (bpp != NULL) {
		error = bread(ip->i_devvp, lbn, (int)fs->fs_bsize, NULL, &nbp);
		if (error) {
			brelse(nbp);
			return error;
		}
		*bpp = nbp;
	}
	return (0);
}

#ifndef __DragonFly__ /* XXX UFS2 */
static int
ffs_balloc_ufs2(struct inode *ip, off_t offset, int bufsize, struct buf **bpp)
{
	daddr_t lbn, lastlbn;
	int size;
	struct buf *bp, *nbp;
	struct fs *fs = ip->i_fs;
	struct indir indirs[UFS_NIADDR + 2];
	daddr_t newb, pref, nb;
	int64_t *bap;
	int osize, nsize, num, i, error;
	int64_t *allocblk, allociblk[UFS_NIADDR + 1];
	int64_t *allocib;
	const int needswap = UFS_FSNEEDSWAP(fs);

	lbn = lblkno(fs, offset);
	size = blkoff(fs, offset) + bufsize;
	if (bpp != NULL) {
		*bpp = NULL;
	}

	assert(size <= fs->fs_bsize);
	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.
	 */

	lastlbn = lblkno(fs, ip->i_ffs2_size);
	if (lastlbn < UFS_NDADDR && lastlbn < lbn) {
		nb = lastlbn;
		osize = blksize(fs, ip, nb);
		if (osize < fs->fs_bsize && osize > 0) {
			warnx("need to ffs_realloccg; not supported!");
			abort();
		}
	}

	/*
	 * The first UFS_NDADDR blocks are direct blocks
	 */

	if (lbn < UFS_NDADDR) {
		nb = ufs_rw64(ip->i_ffs2_db[lbn], needswap);
		if (nb != 0 && ip->i_ffs2_size >=
		    (uint64_t)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(ip->i_devvp, lbn, fs->fs_bsize,
				    NULL, 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_ffs2_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(ip->i_devvp, lbn, osize,
					    NULL, bpp);
					if (error) {
						brelse(*bpp);
						return (error);
					}
				}
				return 0;
			} else {
				warnx("need to ffs_realloccg; not supported!");
				abort();
			}
		} else {

			/*
			 * the block was not previously allocated,
			 * allocate a new block or fragment.
			 */

			if (ip->i_ffs2_size < (uint64_t)lblktosize(fs, lbn + 1))
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			error = ffs_alloc(ip, lbn,
			    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
				&ip->i_ffs2_db[0]),
				nsize, &newb);
			if (error)
				return (error);
			if (bpp != NULL) {
				bp = getblk(ip->i_devvp, lbn, nsize, 0, 0, 0);
				bp->b_blkno = fsbtodb(fs, newb);
				clrbuf(bp);
				*bpp = bp;
			}
		}
		ip->i_ffs2_db[lbn] = ufs_rw64(newb, needswap);
		return (0);
	}

	/*
	 * Determine the number of levels of indirection.
	 */

	pref = 0;
	if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0)
		return (error);

	if (num < 1) {
		warnx("ffs_balloc: ufs_getlbns returned indirect block");
		abort();
	}

	/*
	 * Fetch the first indirect block allocating if necessary.
	 */

	--num;
	nb = ufs_rw64(ip->i_ffs2_ib[indirs[0].in_off], needswap);
	allocib = NULL;
	allocblk = allociblk;
	if (nb == 0) {
		pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0);
		error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
		if (error)
			return error;
		nb = newb;
		*allocblk++ = nb;
		bp = getblk(ip->i_devvp, indirs[1].in_lbn, fs->fs_bsize, 0, 0, 0);
		bp->b_blkno = fsbtodb(fs, nb);
		clrbuf(bp);
		/*
		 * Write synchronously so that indirect blocks
		 * never point at garbage.
		 */
		if ((error = bwrite(bp)) != 0)
			return error;
		allocib = &ip->i_ffs2_ib[indirs[0].in_off];
		*allocib = ufs_rw64(nb, needswap);
	}

	/*
	 * Fetch through the indirect blocks, allocating as necessary.
	 */

	for (i = 1;;) {
		error = bread(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize,
		    NULL, &bp);
		if (error) {
			brelse(bp);
			return error;
		}
		bap = (int64_t *)bp->b_data;
		nb = ufs_rw64(bap[indirs[i].in_off], needswap);
		if (i == num)
			break;
		i++;
		if (nb != 0) {
			brelse(bp);
			continue;
		}
		if (pref == 0)
			pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0);
		error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
		if (error) {
			brelse(bp);
			return error;
		}
		nb = newb;
		*allocblk++ = nb;
		nbp = getblk(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize, 0, 0, 0);
		nbp->b_blkno = fsbtodb(fs, nb);
		clrbuf(nbp);
		/*
		 * Write synchronously so that indirect blocks
		 * never point at garbage.
		 */

		if ((error = bwrite(nbp)) != 0) {
			brelse(bp);
			return error;
		}
		bap[indirs[i - 1].in_off] = ufs_rw64(nb, needswap);

		bwrite(bp);
	}

	/*
	 * Get the data block, allocating if necessary.
	 */

	if (nb == 0) {
		pref = ffs_blkpref_ufs2(ip, lbn, indirs[num].in_off, &bap[0]);
		error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
		if (error) {
			brelse(bp);
			return error;
		}
		nb = newb;
		*allocblk++ = nb;
		if (bpp != NULL) {
			nbp = getblk(ip->i_devvp, lbn, fs->fs_bsize, 0, 0, 0);
			nbp->b_blkno = fsbtodb(fs, nb);
			clrbuf(nbp);
			*bpp = nbp;
		}
		bap[indirs[num].in_off] = ufs_rw64(nb, needswap);

		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		bwrite(bp);
		return (0);
	}
	brelse(bp);
	if (bpp != NULL) {
		error = bread(ip->i_devvp, lbn, (int)fs->fs_bsize, NULL, &nbp);
		if (error) {
			brelse(nbp);
			return error;
		}
		*bpp = nbp;
	}
	return (0);
}
コード例 #2
0
ファイル: ffs_balloc.c プロジェクト: dancrossnyc/harvey
/*
 * 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.
 * This is the allocation strategy for UFS2. Above is
 * the allocation strategy for UFS1.
 */
int
ffs_balloc_ufs2(vnode *vp, off_t startoffset, int size,
    Ucred *cred, int flags, Buf **bpp)
{
	int error = 0;
	print("HARVEY TODO: %s\n", __func__);
#if 0
	struct inode *ip;
	struct ufs2_dinode *dp;
	ufs_lbn_t lbn, lastlbn;
	struct fs *fs;
	struct buf *bp, *nbp;
	struct ufsmount *ump;
	struct indir indirs[UFS_NIADDR + 2];
	ufs2_daddr_t nb, newb, *bap, pref;
	ufs2_daddr_t *allocib, *blkp, *allocblk, allociblk[UFS_NIADDR + 1];
	ufs2_daddr_t *lbns_remfree, lbns[UFS_NIADDR + 1];
	int deallocated, osize, nsize, num, i, error;
	int unwindidx = -1;
	int saved_inbdflush;
	static struct timeval lastfail;
	static int curfail;
	int gbflags, reclaimed;

	ip = VTOI(vp);
	dp = ip->i_din2;
	fs = ITOFS(ip);
	ump = ITOUMP(ip);
	lbn = lblkno(fs, startoffset);
	size = blkoff(fs, startoffset) + size;
	reclaimed = 0;
	if (size > fs->fs_bsize)
		panic("ffs_balloc_ufs2: blk too big");
	*bpp = nil;
	if (lbn < 0)
		return (EFBIG);
	gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;

	if (DOINGSOFTDEP(vp))
		softdep_prealloc(vp, MNT_WAIT);
	
	/*
	 * Check for allocating external data.
	 */
	if (flags & IO_EXT) {
		if (lbn >= UFS_NXADDR)
			return (EFBIG);
		/*
		 * If the next write will extend the data into a new block,
		 * and the data is currently composed of a fragment
		 * this fragment has to be extended to be a full block.
		 */
		lastlbn = lblkno(fs, dp->di_extsize);
		if (lastlbn < lbn) {
			nb = lastlbn;
			osize = sblksize(fs, dp->di_extsize, nb);
			if (osize < fs->fs_bsize && osize > 0) {
				UFS_LOCK(ump);
				error = ffs_realloccg(ip, -1 - nb,
				    dp->di_extb[nb],
				    ffs_blkpref_ufs2(ip, lastlbn, (int)nb,
				    &dp->di_extb[0]), osize,
				    (int)fs->fs_bsize, flags, cred, &bp);
				if (error)
					return (error);
				if (DOINGSOFTDEP(vp))
					softdep_setup_allocext(ip, nb,
					    dbtofsb(fs, bp->b_blkno),
					    dp->di_extb[nb],
					    fs->fs_bsize, osize, bp);
				dp->di_extsize = smalllblktosize(fs, nb + 1);
				dp->di_extb[nb] = dbtofsb(fs, bp->b_blkno);
				bp->b_xflags |= BX_ALTDATA;
				ip->i_flag |= IN_CHANGE;
				if (flags & IO_SYNC)
					bwrite(bp);
				else
					bawrite(bp);
			}
		}
		/*
		 * All blocks are direct blocks
		 */
		if (flags & BA_METAONLY)
			panic("ffs_balloc_ufs2: BA_METAONLY for ext block");
		nb = dp->di_extb[lbn];
		if (nb != 0 && dp->di_extsize >= smalllblktosize(fs, lbn + 1)) {
			error = bread_gb(vp, -1 - lbn, fs->fs_bsize, NOCRED,
			    gbflags, &bp);
			if (error) {
				brelse(bp);
				return (error);
			}
			bp->b_blkno = fsbtodb(fs, nb);
			bp->b_xflags |= BX_ALTDATA;
			*bpp = bp;
			return (0);
		}
		if (nb != 0) {
			/*
			 * Consider need to reallocate a fragment.
			 */
			osize = fragroundup(fs, blkoff(fs, dp->di_extsize));
			nsize = fragroundup(fs, size);
			if (nsize <= osize) {
				error = bread_gb(vp, -1 - lbn, osize, NOCRED,
				    gbflags, &bp);
				if (error) {
					brelse(bp);
					return (error);
				}
				bp->b_blkno = fsbtodb(fs, nb);
				bp->b_xflags |= BX_ALTDATA;
			} else {
				UFS_LOCK(ump);
				error = ffs_realloccg(ip, -1 - lbn,
				    dp->di_extb[lbn],
				    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
				    &dp->di_extb[0]), osize, nsize, flags,
				    cred, &bp);
				if (error)
					return (error);
				bp->b_xflags |= BX_ALTDATA;
				if (DOINGSOFTDEP(vp))
					softdep_setup_allocext(ip, lbn,
					    dbtofsb(fs, bp->b_blkno), nb,
					    nsize, osize, bp);
			}
		} else {
			if (dp->di_extsize < smalllblktosize(fs, lbn + 1))
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			UFS_LOCK(ump);
			error = ffs_alloc(ip, lbn,
			   ffs_blkpref_ufs2(ip, lbn, (int)lbn, &dp->di_extb[0]),
			   nsize, flags, cred, &newb);
			if (error)
				return (error);
			bp = getblk(vp, -1 - lbn, nsize, 0, 0, gbflags);
			bp->b_blkno = fsbtodb(fs, newb);
			bp->b_xflags |= BX_ALTDATA;
			if (flags & BA_CLRBUF)
				vfs_bio_clrbuf(bp);
			if (DOINGSOFTDEP(vp))
				softdep_setup_allocext(ip, lbn, newb, 0,
				    nsize, 0, bp);
		}
		dp->di_extb[lbn] = dbtofsb(fs, bp->b_blkno);
		ip->i_flag |= IN_CHANGE;
		*bpp = bp;
		return (0);
	}
	/*
	 * 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.
	 */
	lastlbn = lblkno(fs, ip->i_size);
	if (lastlbn < UFS_NDADDR && lastlbn < lbn) {
		nb = lastlbn;
		osize = blksize(fs, ip, nb);
		if (osize < fs->fs_bsize && osize > 0) {
			UFS_LOCK(ump);
			error = ffs_realloccg(ip, nb, dp->di_db[nb],
			    ffs_blkpref_ufs2(ip, lastlbn, (int)nb,
			    &dp->di_db[0]), osize, (int)fs->fs_bsize,
			    flags, cred, &bp);
			if (error)
				return (error);
			if (DOINGSOFTDEP(vp))
				softdep_setup_allocdirect(ip, nb,
				    dbtofsb(fs, bp->b_blkno),
				    dp->di_db[nb],
				    fs->fs_bsize, osize, bp);
			ip->i_size = smalllblktosize(fs, nb + 1);
			dp->di_size = ip->i_size;
			dp->di_db[nb] = dbtofsb(fs, bp->b_blkno);
			ip->i_flag |= IN_CHANGE | IN_UPDATE;
			if (flags & IO_SYNC)
				bwrite(bp);
			else
				bawrite(bp);
		}
	}
	/*
	 * The first UFS_NDADDR blocks are direct blocks
	 */
	if (lbn < UFS_NDADDR) {
		if (flags & BA_METAONLY)
			panic("ffs_balloc_ufs2: BA_METAONLY for direct block");
		nb = dp->di_db[lbn];
		if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) {
			error = bread_gb(vp, lbn, fs->fs_bsize, NOCRED,
			    gbflags, &bp);
			if (error) {
				brelse(bp);
				return (error);
			}
			bp->b_blkno = fsbtodb(fs, nb);
			*bpp = bp;
			return (0);
		}
		if (nb != 0) {
			/*
			 * Consider need to reallocate a fragment.
			 */
			osize = fragroundup(fs, blkoff(fs, ip->i_size));
			nsize = fragroundup(fs, size);
			if (nsize <= osize) {
				error = bread_gb(vp, lbn, osize, NOCRED,
				    gbflags, &bp);
				if (error) {
					brelse(bp);
					return (error);
				}
				bp->b_blkno = fsbtodb(fs, nb);
			} else {
				UFS_LOCK(ump);
				error = ffs_realloccg(ip, lbn, dp->di_db[lbn],
				    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
				    &dp->di_db[0]), osize, nsize, flags,
				    cred, &bp);
				if (error)
					return (error);
				if (DOINGSOFTDEP(vp))
					softdep_setup_allocdirect(ip, lbn,
					    dbtofsb(fs, bp->b_blkno), nb,
					    nsize, osize, bp);
			}
		} else {
			if (ip->i_size < smalllblktosize(fs, lbn + 1))
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			UFS_LOCK(ump);
			error = ffs_alloc(ip, lbn,
			    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
				&dp->di_db[0]), nsize, flags, cred, &newb);
			if (error)
				return (error);
			bp = getblk(vp, lbn, nsize, 0, 0, gbflags);
			bp->b_blkno = fsbtodb(fs, newb);
			if (flags & BA_CLRBUF)
				vfs_bio_clrbuf(bp);
			if (DOINGSOFTDEP(vp))
				softdep_setup_allocdirect(ip, lbn, newb, 0,
				    nsize, 0, bp);
		}
		dp->di_db[lbn] = dbtofsb(fs, bp->b_blkno);
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
		*bpp = bp;
		return (0);
	}
	/*
	 * Determine the number of levels of indirection.
	 */
	pref = 0;
	if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
		return(error);
#ifdef INVARIANTS
	if (num < 1)
		panic ("ffs_balloc_ufs2: ufs_getlbns returned indirect block");
#endif
	saved_inbdflush = curthread_pflags_set(TDP_INBDFLUSH);
	/*
	 * Fetch the first indirect block allocating if necessary.
	 */
	--num;
	nb = dp->di_ib[indirs[0].in_off];
	allocib = nil;
	allocblk = allociblk;
	lbns_remfree = lbns;
	if (nb == 0) {
		UFS_LOCK(ump);
		pref = ffs_blkpref_ufs2(ip, lbn, -indirs[0].in_off - 1,
		    (ufs2_daddr_t *)0);
		if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
		    flags, cred, &newb)) != 0) {
			curthread_pflags_restore(saved_inbdflush);
			return (error);
		}
		pref = newb + fs->fs_frag;
		nb = newb;
		MPASS(allocblk < allociblk + nitems(allociblk));
		MPASS(lbns_remfree < lbns + nitems(lbns));
		*allocblk++ = nb;
		*lbns_remfree++ = indirs[1].in_lbn;
		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0,
		    GB_UNMAPPED);
		bp->b_blkno = fsbtodb(fs, nb);
		vfs_bio_clrbuf(bp);
		if (DOINGSOFTDEP(vp)) {
			softdep_setup_allocdirect(ip,
			    UFS_NDADDR + indirs[0].in_off, newb, 0,
			    fs->fs_bsize, 0, bp);
			bdwrite(bp);
		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
			if (bp->b_bufsize == fs->fs_bsize)
				bp->b_flags |= B_CLUSTEROK;
			bdwrite(bp);
		} else {
			if ((error = bwrite(bp)) != 0)
				goto fail;
		}
		allocib = &dp->di_ib[indirs[0].in_off];
		*allocib = nb;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * Fetch through the indirect blocks, allocating as necessary.
	 */
retry:
	for (i = 1;;) {
		error = bread(vp,
		    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
		if (error) {
			brelse(bp);
			goto fail;
		}
		bap = (ufs2_daddr_t *)bp->b_data;
		nb = bap[indirs[i].in_off];
		if (i == num)
			break;
		i += 1;
		if (nb != 0) {
			bqrelse(bp);
			continue;
		}
		UFS_LOCK(ump);
		/*
		 * If parent indirect has just been allocated, try to cluster
		 * immediately following it.
		 */
		if (pref == 0)
			pref = ffs_blkpref_ufs2(ip, lbn, i - num - 1,
			    (ufs2_daddr_t *)0);
		if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
		    flags | IO_BUFLOCKED, cred, &newb)) != 0) {
			brelse(bp);
			if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
				UFS_LOCK(ump);
				softdep_request_cleanup(fs, vp, cred,
				    FLUSH_BLOCKS_WAIT);
				UFS_UNLOCK(ump);
				goto retry;
			}
			if (ppsratecheck(&lastfail, &curfail, 1)) {
				ffs_fserr(fs, ip->i_number, "filesystem full");
				uprintf("\n%s: write failed, filesystem "
				    "is full\n", fs->fs_fsmnt);
			}
			goto fail;
		}
		pref = newb + fs->fs_frag;
		nb = newb;
		MPASS(allocblk < allociblk + nitems(allociblk));
		MPASS(lbns_remfree < lbns + nitems(lbns));
		*allocblk++ = nb;
		*lbns_remfree++ = indirs[i].in_lbn;
		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0,
		    GB_UNMAPPED);
		nbp->b_blkno = fsbtodb(fs, nb);
		vfs_bio_clrbuf(nbp);
		if (DOINGSOFTDEP(vp)) {
			softdep_setup_allocindir_meta(nbp, ip, bp,
			    indirs[i - 1].in_off, nb);
			bdwrite(nbp);
		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
			if (nbp->b_bufsize == fs->fs_bsize)
				nbp->b_flags |= B_CLUSTEROK;
			bdwrite(nbp);
		} else {
			if ((error = bwrite(nbp)) != 0) {
				brelse(bp);
				goto fail;
			}
		}
		bap[indirs[i - 1].in_off] = nb;
		if (allocib == nil && unwindidx < 0)
			unwindidx = i - 1;
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if (flags & IO_SYNC) {
			bwrite(bp);
		} else {
			if (bp->b_bufsize == fs->fs_bsize)
				bp->b_flags |= B_CLUSTEROK;
			bdwrite(bp);
		}
	}
	/*
	 * If asked only for the indirect block, then return it.
	 */
	if (flags & BA_METAONLY) {
		curthread_pflags_restore(saved_inbdflush);
		*bpp = bp;
		return (0);
	}
	/*
	 * Get the data block, allocating if necessary.
	 */
	if (nb == 0) {
		UFS_LOCK(ump);
		/*
		 * If allocating metadata at the front of the cylinder
		 * group and parent indirect block has just been allocated,
		 * then cluster next to it if it is the first indirect in
		 * the file. Otherwise it has been allocated in the metadata
		 * area, so we want to find our own place out in the data area.
		 */
		if (pref == 0 || (lbn > UFS_NDADDR && fs->fs_metaspace != 0))
			pref = ffs_blkpref_ufs2(ip, lbn, indirs[i].in_off,
			    &bap[0]);
		error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
		    flags | IO_BUFLOCKED, cred, &newb);
		if (error) {
			brelse(bp);
			if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
				UFS_LOCK(ump);
				softdep_request_cleanup(fs, vp, cred,
				    FLUSH_BLOCKS_WAIT);
				UFS_UNLOCK(ump);
				goto retry;
			}
			if (ppsratecheck(&lastfail, &curfail, 1)) {
				ffs_fserr(fs, ip->i_number, "filesystem full");
				uprintf("\n%s: write failed, filesystem "
				    "is full\n", fs->fs_fsmnt);
			}
			goto fail;
		}
		nb = newb;
		MPASS(allocblk < allociblk + nitems(allociblk));
		MPASS(lbns_remfree < lbns + nitems(lbns));
		*allocblk++ = nb;
		*lbns_remfree++ = lbn;
		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, gbflags);
		nbp->b_blkno = fsbtodb(fs, nb);
		if (flags & BA_CLRBUF)
			vfs_bio_clrbuf(nbp);
		if (DOINGSOFTDEP(vp))
			softdep_setup_allocindir_page(ip, lbn, bp,
			    indirs[i].in_off, nb, 0, nbp);
		bap[indirs[i].in_off] = nb;
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if (flags & IO_SYNC) {
			bwrite(bp);
		} else {
			if (bp->b_bufsize == fs->fs_bsize)
				bp->b_flags |= B_CLUSTEROK;
			bdwrite(bp);
		}
		curthread_pflags_restore(saved_inbdflush);
		*bpp = nbp;
		return (0);
	}
	brelse(bp);
	/*
	 * If requested clear invalid portions of the buffer.  If we
	 * have to do a read-before-write (typical if BA_CLRBUF is set),
	 * try to do some read-ahead in the sequential case to reduce
	 * the number of I/O transactions.
	 */
	if (flags & BA_CLRBUF) {
		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
		if (seqcount != 0 &&
		    (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0 &&
		    !(vm_page_count_severe() || buf_dirty_count_severe())) {
			error = cluster_read(vp, ip->i_size, lbn,
			    (int)fs->fs_bsize, NOCRED,
			    MAXBSIZE, seqcount, gbflags, &nbp);
		} else {
			error = bread_gb(vp, lbn, (int)fs->fs_bsize,
			    NOCRED, gbflags, &nbp);
		}
		if (error) {
			brelse(nbp);
			goto fail;
		}
	} else {