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Date:      Sun, 7 Jul 2019 08:56:13 +0000 (UTC)
From:      Fedor Uporov <fsu@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r349801 - head/sys/fs/ext2fs
Message-ID:  <201907070856.x678uDeR067108@repo.freebsd.org>
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Author: fsu
Date: Sun Jul  7 08:56:13 2019
New Revision: 349801
URL: https://svnweb.freebsd.org/changeset/base/349801

Log:
  Remove ufs fragments logic.
  
  The ext2fs fragments are different from ufs fragments.
  In case of ext2fs the fragment should be equal or more then block size.
  The values more than block size are used only in case of bigalloc feature, which is does not supported for now.
  
  Reported by:    Christopher Krah, Thomas Barabosch, and Jan-Niclas Hilgert of Fraunhofer FKIE
  Reported as:    FS-22-EXT2-9: Denial of service in ftruncate-0 (ext2_balloc)
  
  MFC after:	2 weeks

Modified:
  head/sys/fs/ext2fs/ext2_balloc.c

Modified: head/sys/fs/ext2fs/ext2_balloc.c
==============================================================================
--- head/sys/fs/ext2fs/ext2_balloc.c	Sun Jul  7 08:53:52 2019	(r349800)
+++ head/sys/fs/ext2fs/ext2_balloc.c	Sun Jul  7 08:56:13 2019	(r349801)
@@ -62,7 +62,7 @@ ext2_ext_balloc(struct inode *ip, uint32_t lbn, int si
 	struct buf *bp = NULL;
 	struct vnode *vp = ITOV(ip);
 	daddr_t newblk;
-	int osize, nsize, blks, error, allocated;
+	int blks, error, allocated;
 
 	fs = ip->i_e2fs;
 	blks = howmany(size, fs->e2fs_bsize);
@@ -72,47 +72,22 @@ ext2_ext_balloc(struct inode *ip, uint32_t lbn, int si
 		return (error);
 
 	if (allocated) {
-		if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
-			nsize = fragroundup(fs, size);
-		else
-			nsize = fs->e2fs_bsize;
-
-		bp = getblk(vp, lbn, nsize, 0, 0, 0);
+		bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
 		if(!bp)
 			return (EIO);
-
-		bp->b_blkno = fsbtodb(fs, newblk);
-		if (flags & BA_CLRBUF)
-			vfs_bio_clrbuf(bp);
 	} else {
-		if (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, newblk);
-			*bpp = bp;
-			return (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);
-		else
-			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
+		error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
 		if (error) {
 			brelse(bp);
 			return (error);
 		}
-		bp->b_blkno = fsbtodb(fs, newblk);
 	}
 
+
+	bp->b_blkno = fsbtodb(fs, newblk);
+	if (flags & BA_CLRBUF)
+		vfs_bio_clrbuf(bp);
+
 	*bpp = bp;
 
 	return (error);
@@ -134,7 +109,7 @@ ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size
 	struct indir indirs[EXT2_NIADDR + 2];
 	e4fs_daddr_t nb, newb;
 	e2fs_daddr_t *bap, pref;
-	int osize, nsize, num, i, error;
+	int num, i, error;
 
 	*bpp = NULL;
 	if (lbn < 0)
@@ -164,53 +139,22 @@ ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size
 		 * 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) {
+		if (nb != 0) {
 			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.
- */
+			if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
+				*bpp = bp;
+				return (0);
 			}
 		} 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);
+			    fs->e2fs_bsize, cred, &newb);
 			if (error)
 				return (error);
 			/*
@@ -219,7 +163,7 @@ ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size
 			 */
 			if (newb > UINT_MAX)
 				return (EFBIG);
-			bp = getblk(vp, lbn, nsize, 0, 0, 0);
+			bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
 			bp->b_blkno = fsbtodb(fs, newb);
 			if (flags & BA_CLRBUF)
 				vfs_bio_clrbuf(bp);

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