BSD 4.4 Lite Kernel Sources

1 files changed, 282 insertions, 0 deletions

diff --git a/sys/ufs/ffs/ffs_balloc.c b/sys/ufs/ffs/ffs_balloc.c
new file mode 100644
index 0000000..752feec
--- /dev/null
+++ b/sys/ufs/ffs/ffs_balloc.c
@@ -0,0 +1,282 @@
+/*
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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/vnode.h>
+
+#include <vm/vm.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.
+ */
+ffs_balloc(ip, bn, size, cred, bpp, flags)
+	register struct inode *ip;
+	register daddr_t bn;
+	int size;
+	struct ucred *cred;
+	struct buf **bpp;
+	int flags;
+{
+	register struct fs *fs;
+	register daddr_t nb;
+	struct buf *bp, *nbp;
+	struct vnode *vp = ITOV(ip);
+	struct indir indirs[NIADDR + 2];
+	daddr_t newb, lbn, *bap, pref;
+	int osize, nsize, num, i, error;
+
+	*bpp = NULL;
+	if (bn < 0)
+		return (EFBIG);
+	fs = ip->i_fs;
+	lbn = bn;
+
+	/*
+	 * 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_size);
+	if (nb < NDADDR && nb < bn) {
+		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_db[0]),
+				osize, (int)fs->fs_bsize, cred, &bp);
+			if (error)
+				return (error);
+			ip->i_size = (nb + 1) * fs->fs_bsize;
+			vnode_pager_setsize(vp, (u_long)ip->i_size);
+			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
+			ip->i_flag |= IN_CHANGE | IN_UPDATE;
+			if (flags & B_SYNC)
+				bwrite(bp);
+			else
+				bawrite(bp);
+		}
+	}
+	/*
+	 * The first NDADDR blocks are direct blocks
+	 */
+	if (bn < NDADDR) {
+		nb = ip->i_db[bn];
+		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
+			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
+			if (error) {
+				brelse(bp);
+				return (error);
+			}
+			*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(vp, bn, osize, NOCRED, &bp);
+				if (error) {
+					brelse(bp);
+					return (error);
+				}
+			} else {
+				error = ffs_realloccg(ip, bn,
+				    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
+				    osize, nsize, cred, &bp);
+				if (error)
+					return (error);
+			}
+		} else {
+			if (ip->i_size < (bn + 1) * fs->fs_bsize)
+				nsize = fragroundup(fs, size);
+			else
+				nsize = fs->fs_bsize;
+			error = ffs_alloc(ip, bn,
+			    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
+			    nsize, cred, &newb);
+			if (error)
+				return (error);
+			bp = getblk(vp, bn, nsize, 0, 0);
+			bp->b_blkno = fsbtodb(fs, newb);
+			if (flags & B_CLRBUF)
+				clrbuf(bp);
+		}
+		ip->i_db[bn] = 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, bn, indirs, &num))
+		return(error);
+#ifdef DIAGNOSTIC
+	if (num < 1)
+		panic ("ffs_balloc: ufs_bmaparray returned indirect block\n");
+#endif
+	/*
+	 * Fetch the first indirect block allocating if necessary.
+	 */
+	--num;
+	nb = ip->i_ib[indirs[0].in_off];
+	if (nb == 0) {
+		pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
+	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
+		    cred, &newb))
+			return (error);
+		nb = newb;
+		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
+		bp->b_blkno = fsbtodb(fs, newb);
+		clrbuf(bp);
+		/*
+		 * Write synchronously so that indirect blocks
+		 * never point at garbage.
+		 */
+		if (error = bwrite(bp)) {
+			ffs_blkfree(ip, nb, fs->fs_bsize);
+			return (error);
+		}
+		ip->i_ib[indirs[0].in_off] = newb;
+		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);
+			return (error);
+		}
+		bap = (daddr_t *)bp->b_data;
+		nb = bap[indirs[i].in_off];
+		if (i == num)
+			break;
+		i += 1;
+		if (nb != 0) {
+			brelse(bp);
+			continue;
+		}
+		if (pref == 0)
+			pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
+		if (error =
+		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
+			brelse(bp);
+			return (error);
+		}
+		nb = newb;
+		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+		clrbuf(nbp);
+		/*
+		 * Write synchronously so that indirect blocks
+		 * never point at garbage.
+		 */
+		if (error = bwrite(nbp)) {
+			ffs_blkfree(ip, nb, fs->fs_bsize);
+			brelse(bp);
+			return (error);
+		}
+		bap[indirs[i - 1].in_off] = nb;
+		/*
+		 * 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]);
+		if (error = ffs_alloc(ip,
+		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
+			brelse(bp);
+			return (error);
+		}
+		nb = newb;
+		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+		if (flags & B_CLRBUF)
+			clrbuf(nbp);
+		bap[indirs[i].in_off] = nb;
+		/*
+		 * If required, write synchronously, otherwise use
+		 * delayed write.
+		 */
+		if (flags & B_SYNC) {
+			bwrite(bp);
+		} else {
+			bdwrite(bp);
+		}
+		*bpp = nbp;
+		return (0);
+	}
+	brelse(bp);
+	if (flags & B_CLRBUF) {
+		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
+		if (error) {
+			brelse(nbp);
+			return (error);
+		}
+	} else {
+		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+	}
+	*bpp = nbp;
+	return (0);
+}