Bring in the ext2fs work done by Aditya Sarawgi during and after Google Summer

of Code 2009:

- BSDL block and inode allocation policies for ext2fs. This involves the use
  FFS1 style block and inode allocation for ext2fs. Preallocation was removed
  since it was GPL'd.
- Make ext2fs MPSAFE by introducing locks to per-mount datastructures.
- Fixes for kern/122047 PR.
- Various small bugfixes.
- Move out of gnu/ directory.

Sponsored by:   Google Inc.
Submitted by:	Aditya Sarawgi <sarawgi.aditya AT SPAMFREE gmail DOT com>

1 files changed, 292 insertions, 0 deletions

diff --git a/sys/fs/ext2fs/ext2_balloc.c b/sys/fs/ext2fs/ext2_balloc.c
new file mode 100644
index 000000000000..124ac32ddf1c
--- /dev/null
+++ b/sys/fs/ext2fs/ext2_balloc.c
@@ -0,0 +1,292 @@
+/*-
+ *  modified for Lites 1.1
+ *
+ *  Aug 1995, Godmar Back (gback@cs.utah.edu)
+ *  University of Utah, Department of Computer Science
+ */
+/*-
+ * 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.
+ * 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
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bio.h>
+#include <sys/buf.h>
+#include <sys/lock.h>
+#include <sys/ucred.h>
+#include <sys/vnode.h>
+
+#include <fs/ext2fs/inode.h>
+#include <fs/ext2fs/ext2fs.h>
+#include <fs/ext2fs/fs.h>
+#include <fs/ext2fs/ext2_extern.h>
+#include <fs/ext2fs/ext2_mount.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
+ext2_balloc(ip, lbn, size, cred, bpp, flags)
+	struct inode *ip;
+	int32_t lbn;
+	int size;
+	struct ucred *cred;
+	struct buf **bpp;
+	int flags;
+{
+	struct m_ext2fs *fs;
+	struct ext2mount *ump;
+	int32_t nb;
+	struct buf *bp, *nbp;
+	struct vnode *vp = ITOV(ip);
+	struct indir indirs[NIADDR + 2];
+	int32_t newb, *bap, pref;
+	int osize, nsize, num, i, error;
+
+	*bpp = NULL;
+	if (lbn < 0)
+		return (EFBIG);
+	fs = ip->i_e2fs;
+	ump = ip->i_ump;
+
+	/*
+	 * check if this is a sequential block allocation. 
+	 * If so, increment next_alloc fields to allow ext2_blkpref 
+	 * to make a good guess
+	 */
+        if (lbn == ip->i_next_alloc_block + 1) {
+		ip->i_next_alloc_block++;
+		ip->i_next_alloc_goal++;
+	}
+
+	/*
+	 * The first NDADDR blocks are direct blocks
+	 */
+	if (lbn < NDADDR) {
+		nb = ip->i_db[lbn];
+		/* no new block is to be allocated, and no need to expand
+		   the file */
+		if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
+			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &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(vp, lbn, osize, NOCRED, &bp);
+				if (error) {
+					brelse(bp);
+					return (error);
+				}
+				bp->b_blkno = fsbtodb(fs, nb);
+			} else {
+			/* Godmar thinks: this shouldn't happen w/o fragments */
+				printf("nsize %d(%d) > osize %d(%d) nb %d\n", 
+					(int)nsize, (int)size, (int)osize, 
+					(int)ip->i_size, (int)nb);
+				panic(
+				    "ext2_balloc: Something is terribly wrong");
+/*
+ * please note there haven't been any changes from here on -
+ * FFS seems to work.
+ */
+			}
+		} else {
+			if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
+				nsize = fragroundup(fs, size);
+			else
+				nsize = fs->e2fs_bsize;
+			EXT2_LOCK(ump);
+			error = ext2_alloc(ip, lbn,
+			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
+			    nsize, cred, &newb);
+			if (error)
+				return (error);
+			bp = getblk(vp, lbn, nsize, 0, 0, 0);
+			bp->b_blkno = fsbtodb(fs, newb);
+			if (flags & B_CLRBUF)
+				vfs_bio_clrbuf(bp);
+		}
+		ip->i_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 = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
+		return(error);
+#ifdef DIAGNOSTIC
+	if (num < 1)
+		panic ("ext2_balloc: ext2_getlbns returned indirect block");
+#endif
+	/*
+	 * Fetch the first indirect block allocating if necessary.
+	 */
+	--num;
+	nb = ip->i_ib[indirs[0].in_off];
+	if (nb == 0) {
+		EXT2_LOCK(ump);
+		pref = ext2_blkpref(ip, lbn, indirs[0].in_off + 
+					     EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
+	        if ((error = ext2_alloc(ip, lbn, pref, 
+			(int)fs->e2fs_bsize, cred, &newb)))
+			return (error);
+		nb = newb;
+		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
+		bp->b_blkno = fsbtodb(fs, newb);
+		vfs_bio_clrbuf(bp);
+		/*
+		 * Write synchronously so that indirect blocks
+		 * never point at garbage.
+		 */
+		if ((error = bwrite(bp)) != 0) {
+			ext2_blkfree(ip, nb, fs->e2fs_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->e2fs_bsize, NOCRED, &bp);
+		if (error) {
+			brelse(bp);
+			return (error);
+		}
+		bap = (int32_t *)bp->b_data;
+		nb = bap[indirs[i].in_off];
+		if (i == num)
+			break;
+		i += 1;
+		if (nb != 0) {
+			bqrelse(bp);
+			continue;
+		}
+		EXT2_LOCK(ump);
+		if (pref == 0)
+			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
+						bp->b_lblkno);
+		error =  ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
+		if (error) {
+			brelse(bp);
+			return (error);
+		}
+		nb = newb;
+		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+		vfs_bio_clrbuf(nbp);
+		/*
+		 * Write synchronously so that indirect blocks
+		 * never point at garbage.
+		 */
+		if ((error = bwrite(nbp)) != 0) {
+			ext2_blkfree(ip, nb, fs->e2fs_bsize);
+			EXT2_UNLOCK(ump);
+			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 {
+			if (bp->b_bufsize == fs->e2fs_bsize)
+				bp->b_flags |= B_CLUSTEROK;
+			bdwrite(bp);
+		}
+	}
+	/*
+	 * Get the data block, allocating if necessary.
+	 */
+	if (nb == 0) {
+		EXT2_LOCK(ump);
+		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0], 
+				bp->b_lblkno);
+		if ((error = ext2_alloc(ip,
+		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
+			brelse(bp);
+			return (error);
+		}
+		nb = newb;
+		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+		if (flags & B_CLRBUF)
+			vfs_bio_clrbuf(nbp);
+		bap[indirs[i].in_off] = nb;
+		/*
+		 * If required, write synchronously, otherwise use
+		 * delayed write.
+		 */
+		if (flags & B_SYNC) {
+			bwrite(bp);
+		} else {
+		if (bp->b_bufsize == fs->e2fs_bsize)
+				bp->b_flags |= B_CLUSTEROK;
+			bdwrite(bp);
+		}
+		*bpp = nbp;
+		return (0);
+	}
+	brelse(bp);
+	if (flags & B_CLRBUF) {
+		error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
+		if (error) {
+			brelse(nbp);
+			return (error);
+		}
+	} else {
+		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
+		nbp->b_blkno = fsbtodb(fs, nb);
+	}
+	*bpp = nbp;
+	return (0);
+}
+