diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 01b97c012c6e..3814a60e0aea 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -38,11 +38,6 @@ struct metapath {
 	__u16 mp_list[GFS2_MAX_META_HEIGHT];
 };
 
-struct strip_mine {
-	int sm_first;
-	unsigned int sm_height;
-};
-
 /**
  * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
  * @ip: the inode
@@ -252,6 +247,19 @@ static inline unsigned int metapath_branch_start(const struct metapath *mp)
 	return 1;
 }
 
+/**
+ * metaptr1 - Return the first possible metadata pointer in a metaath buffer
+ * @height: The metadata height (0 = dinode)
+ * @mp: The metapath
+ */
+static inline __be64 *metaptr1(unsigned int height, const struct metapath *mp)
+{
+	struct buffer_head *bh = mp->mp_bh[height];
+	if (height == 0)
+		return ((__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)));
+	return ((__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header)));
+}
+
 /**
  * metapointer - Return pointer to start of metadata in a buffer
  * @height: The metadata height (0 = dinode)
@@ -264,10 +272,8 @@ static inline unsigned int metapath_branch_start(const struct metapath *mp)
 
 static inline __be64 *metapointer(unsigned int height, const struct metapath *mp)
 {
-	struct buffer_head *bh = mp->mp_bh[height];
-	unsigned int head_size = (height > 0) ?
-		sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode);
-	return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height];
+	__be64 *p = metaptr1(height, mp);
+	return p + mp->mp_list[height];
 }
 
 static void gfs2_metapath_ra(struct gfs2_glock *gl,
@@ -295,6 +301,23 @@ static void gfs2_metapath_ra(struct gfs2_glock *gl,
 	}
 }
 
+/**
+ * lookup_mp_height - helper function for lookup_metapath
+ * @ip: the inode
+ * @mp: the metapath
+ * @h: the height which needs looking up
+ */
+static int lookup_mp_height(struct gfs2_inode *ip, struct metapath *mp, int h)
+{
+	__be64 *ptr = metapointer(h, mp);
+	u64 dblock = be64_to_cpu(*ptr);
+
+	if (!dblock)
+		return h + 1;
+
+	return gfs2_meta_indirect_buffer(ip, h + 1, dblock, &mp->mp_bh[h + 1]);
+}
+
 /**
  * lookup_metapath - Walk the metadata tree to a specific point
  * @ip: The inode
@@ -316,17 +339,10 @@ static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
 {
 	unsigned int end_of_metadata = ip->i_height - 1;
 	unsigned int x;
-	__be64 *ptr;
-	u64 dblock;
 	int ret;
 
 	for (x = 0; x < end_of_metadata; x++) {
-		ptr = metapointer(x, mp);
-		dblock = be64_to_cpu(*ptr);
-		if (!dblock)
-			return x + 1;
-
-		ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, &mp->mp_bh[x+1]);
+		ret = lookup_mp_height(ip, mp, x);
 		if (ret)
 			return ret;
 	}
@@ -334,6 +350,35 @@ static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
 	return ip->i_height;
 }
 
+/**
+ * fillup_metapath - fill up buffers for the metadata path to a specific height
+ * @ip: The inode
+ * @mp: The metapath
+ * @h: The height to which it should be mapped
+ *
+ * Similar to lookup_metapath, but does lookups for a range of heights
+ *
+ * Returns: error or height of metadata tree
+ */
+
+static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h)
+{
+	unsigned int start_h = h - 1;
+	int ret;
+
+	if (h) {
+		/* find the first buffer we need to look up. */
+		while (start_h > 0 && mp->mp_bh[start_h] == NULL)
+			start_h--;
+		for (; start_h < h; start_h++) {
+			ret = lookup_mp_height(ip, mp, start_h);
+			if (ret)
+				return ret;
+		}
+	}
+	return ip->i_height;
+}
+
 static inline void release_metapath(struct metapath *mp)
 {
 	int i;
@@ -422,6 +467,13 @@ enum alloc_state {
 	/* ALLOC_UNSTUFF = 3,   TBD and rather complicated */
 };
 
+static inline unsigned int hptrs(struct gfs2_sbd *sdp, const unsigned int hgt)
+{
+	if (hgt)
+		return sdp->sd_inptrs;
+	return sdp->sd_diptrs;
+}
+
 /**
  * gfs2_bmap_alloc - Build a metadata tree of the requested height
  * @inode: The GFS2 inode
@@ -620,7 +672,7 @@ int gfs2_block_map(struct inode *inode, sector_t lblock,
 
 	BUG_ON(maxlen == 0);
 
-	memset(mp.mp_bh, 0, sizeof(mp.mp_bh));
+	memset(&mp, 0, sizeof(mp));
 	bmap_lock(ip, create);
 	clear_buffer_mapped(bh_map);
 	clear_buffer_new(bh_map);
@@ -701,252 +753,6 @@ int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsi
 	return ret;
 }
 
-/**
- * do_strip - Look for a layer a particular layer of the file and strip it off
- * @ip: the inode
- * @dibh: the dinode buffer
- * @bh: A buffer of pointers
- * @top: The first pointer in the buffer
- * @bottom: One more than the last pointer
- * @height: the height this buffer is at
- * @sm: a pointer to a struct strip_mine
- *
- * Returns: errno
- */
-
-static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
-		    struct buffer_head *bh, __be64 *top, __be64 *bottom,
-		    unsigned int height, struct strip_mine *sm)
-{
-	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	struct gfs2_rgrp_list rlist;
-	struct gfs2_trans *tr;
-	u64 bn, bstart;
-	u32 blen, btotal;
-	__be64 *p;
-	unsigned int rg_blocks = 0;
-	int metadata;
-	unsigned int revokes = 0;
-	int x;
-	int error;
-	int jblocks_rqsted;
-
-	error = gfs2_rindex_update(sdp);
-	if (error)
-		return error;
-
-	if (!*top)
-		sm->sm_first = 0;
-
-	if (height != sm->sm_height)
-		return 0;
-
-	if (sm->sm_first) {
-		top++;
-		sm->sm_first = 0;
-	}
-
-	metadata = (height != ip->i_height - 1);
-	if (metadata)
-		revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs;
-	else if (ip->i_depth)
-		revokes = sdp->sd_inptrs;
-
-	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
-	bstart = 0;
-	blen = 0;
-
-	for (p = top; p < bottom; p++) {
-		if (!*p)
-			continue;
-
-		bn = be64_to_cpu(*p);
-
-		if (bstart + blen == bn)
-			blen++;
-		else {
-			if (bstart)
-				gfs2_rlist_add(ip, &rlist, bstart);
-
-			bstart = bn;
-			blen = 1;
-		}
-	}
-
-	if (bstart)
-		gfs2_rlist_add(ip, &rlist, bstart);
-	else
-		goto out; /* Nothing to do */
-
-	gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
-
-	for (x = 0; x < rlist.rl_rgrps; x++) {
-		struct gfs2_rgrpd *rgd;
-		rgd = rlist.rl_ghs[x].gh_gl->gl_object;
-		rg_blocks += rgd->rd_length;
-	}
-
-	error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
-	if (error)
-		goto out_rlist;
-
-	if (gfs2_rs_active(&ip->i_res)) /* needs to be done with the rgrp glock held */
-		gfs2_rs_deltree(&ip->i_res);
-
-restart:
-	jblocks_rqsted = rg_blocks + RES_DINODE +
-		RES_INDIRECT + RES_STATFS + RES_QUOTA +
-		gfs2_struct2blk(sdp, revokes, sizeof(u64));
-	if (jblocks_rqsted > atomic_read(&sdp->sd_log_thresh2))
-		jblocks_rqsted = atomic_read(&sdp->sd_log_thresh2);
-	error = gfs2_trans_begin(sdp, jblocks_rqsted, revokes);
-	if (error)
-		goto out_rg_gunlock;
-
-	tr = current->journal_info;
-	down_write(&ip->i_rw_mutex);
-
-	gfs2_trans_add_meta(ip->i_gl, dibh);
-	gfs2_trans_add_meta(ip->i_gl, bh);
-
-	bstart = 0;
-	blen = 0;
-	btotal = 0;
-
-	for (p = top; p < bottom; p++) {
-		if (!*p)
-			continue;
-
-		/* check for max reasonable journal transaction blocks */
-		if (tr->tr_num_buf_new + RES_STATFS +
-		    RES_QUOTA >= atomic_read(&sdp->sd_log_thresh2)) {
-			if (rg_blocks >= tr->tr_num_buf_new)
-				rg_blocks -= tr->tr_num_buf_new;
-			else
-				rg_blocks = 0;
-			break;
-		}
-
-		bn = be64_to_cpu(*p);
-
-		if (bstart + blen == bn)
-			blen++;
-		else {
-			if (bstart) {
-				__gfs2_free_blocks(ip, bstart, blen, metadata);
-				btotal += blen;
-			}
-
-			bstart = bn;
-			blen = 1;
-		}
-
-		*p = 0;
-		gfs2_add_inode_blocks(&ip->i_inode, -1);
-	}
-	if (p == bottom)
-		rg_blocks = 0;
-
-	if (bstart) {
-		__gfs2_free_blocks(ip, bstart, blen, metadata);
-		btotal += blen;
-	}
-
-	gfs2_statfs_change(sdp, 0, +btotal, 0);
-	gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
-			  ip->i_inode.i_gid);
-
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
-
-	gfs2_dinode_out(ip, dibh->b_data);
-
-	up_write(&ip->i_rw_mutex);
-
-	gfs2_trans_end(sdp);
-
-	if (rg_blocks)
-		goto restart;
-
-out_rg_gunlock:
-	gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
-out_rlist:
-	gfs2_rlist_free(&rlist);
-out:
-	return error;
-}
-
-/**
- * recursive_scan - recursively scan through the end of a file
- * @ip: the inode
- * @dibh: the dinode buffer
- * @mp: the path through the metadata to the point to start
- * @height: the height the recursion is at
- * @block: the indirect block to look at
- * @first: 1 if this is the first block
- * @sm: data opaque to this function to pass to @bc
- *
- * When this is first called @height and @block should be zero and
- * @first should be 1.
- *
- * Returns: errno
- */
-
-static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh,
-			  struct metapath *mp, unsigned int height,
-			  u64 block, int first, struct strip_mine *sm)
-{
-	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	struct buffer_head *bh = NULL;
-	__be64 *top, *bottom;
-	u64 bn;
-	int error;
-	int mh_size = sizeof(struct gfs2_meta_header);
-
-	if (!height) {
-		error = gfs2_meta_inode_buffer(ip, &bh);
-		if (error)
-			return error;
-		dibh = bh;
-
-		top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0];
-		bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs;
-	} else {
-		error = gfs2_meta_indirect_buffer(ip, height, block, &bh);
-		if (error)
-			return error;
-
-		top = (__be64 *)(bh->b_data + mh_size) +
-				  (first ? mp->mp_list[height] : 0);
-
-		bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs;
-	}
-
-	error = do_strip(ip, dibh, bh, top, bottom, height, sm);
-	if (error)
-		goto out;
-
-	if (height < ip->i_height - 1) {
-
-		gfs2_metapath_ra(ip->i_gl, bh, top);
-
-		for (; top < bottom; top++, first = 0) {
-			if (!*top)
-				continue;
-
-			bn = be64_to_cpu(*top);
-
-			error = recursive_scan(ip, dibh, mp, height + 1, bn,
-					       first, sm);
-			if (error)
-				break;
-		}
-	}
-out:
-	brelse(bh);
-	return error;
-}
-
-
 /**
  * gfs2_block_truncate_page - Deal with zeroing out data for truncate
  *
@@ -1106,41 +912,406 @@ out:
 	return error;
 }
 
-static int trunc_dealloc(struct gfs2_inode *ip, u64 size)
+/**
+ * sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein
+ * @ip: inode
+ * @rg_gh: holder of resource group glock
+ * @mp: current metapath fully populated with buffers
+ * @btotal: place to keep count of total blocks freed
+ * @hgt: height we're processing
+ * @first: true if this is the first call to this function for this height
+ *
+ * We sweep a metadata buffer (provided by the metapath) for blocks we need to
+ * free, and free them all. However, we do it one rgrp at a time. If this
+ * block has references to multiple rgrps, we break it into individual
+ * transactions. This allows other processes to use the rgrps while we're
+ * focused on a single one, for better concurrency / performance.
+ * At every transaction boundary, we rewrite the inode into the journal.
+ * That way the bitmaps are kept consistent with the inode and we can recover
+ * if we're interrupted by power-outages.
+ *
+ * Returns: 0, or return code if an error occurred.
+ *          *btotal has the total number of blocks freed
+ */
+static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh,
+			      const struct metapath *mp, u32 *btotal, int hgt,
+			      bool preserve1)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	unsigned int height = ip->i_height;
-	u64 lblock;
-	struct metapath mp;
-	int error;
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_trans *tr;
+	struct buffer_head *bh = mp->mp_bh[hgt];
+	__be64 *top, *bottom, *p;
+	int blks_outside_rgrp;
+	u64 bn, bstart, isize_blks;
+	s64 blen; /* needs to be s64 or gfs2_add_inode_blocks breaks */
+	int meta = ((hgt != ip->i_height - 1) ? 1 : 0);
+	int ret = 0;
+	bool buf_in_tr = false; /* buffer was added to transaction */
 
-	if (!size)
+	if (gfs2_metatype_check(sdp, bh,
+				(hgt ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)))
+		return -EIO;
+
+more_rgrps:
+	blks_outside_rgrp = 0;
+	bstart = 0;
+	blen = 0;
+	top = metapointer(hgt, mp); /* first ptr from metapath */
+	/* If we're keeping some data at the truncation point, we've got to
+	   preserve the metadata tree by adding 1 to the starting metapath. */
+	if (preserve1)
+		top++;
+
+	bottom = (__be64 *)(bh->b_data + bh->b_size);
+
+	for (p = top; p < bottom; p++) {
+		if (!*p)
+			continue;
+		bn = be64_to_cpu(*p);
+		if (gfs2_holder_initialized(rd_gh)) {
+			rgd = (struct gfs2_rgrpd *)rd_gh->gh_gl->gl_object;
+			gfs2_assert_withdraw(sdp,
+				     gfs2_glock_is_locked_by_me(rd_gh->gh_gl));
+		} else {
+			rgd = gfs2_blk2rgrpd(sdp, bn, false);
+			ret = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
+						 0, rd_gh);
+			if (ret)
+				goto out;
+
+			/* Must be done with the rgrp glock held: */
+			if (gfs2_rs_active(&ip->i_res) &&
+			    rgd == ip->i_res.rs_rbm.rgd)
+				gfs2_rs_deltree(&ip->i_res);
+		}
+
+		if (!rgrp_contains_block(rgd, bn)) {
+			blks_outside_rgrp++;
+			continue;
+		}
+
+		/* The size of our transactions will be unknown until we
+		   actually process all the metadata blocks that relate to
+		   the rgrp. So we estimate. We know it can't be more than
+		   the dinode's i_blocks and we don't want to exceed the
+		   journal flush threshold, sd_log_thresh2. */
+		if (current->journal_info == NULL) {
+			unsigned int jblocks_rqsted, revokes;
+
+			jblocks_rqsted = rgd->rd_length + RES_DINODE +
+				RES_INDIRECT;
+			isize_blks = gfs2_get_inode_blocks(&ip->i_inode);
+			if (isize_blks > atomic_read(&sdp->sd_log_thresh2))
+				jblocks_rqsted +=
+					atomic_read(&sdp->sd_log_thresh2);
+			else
+				jblocks_rqsted += isize_blks;
+			revokes = jblocks_rqsted;
+			if (meta)
+				revokes += hptrs(sdp, hgt);
+			else if (ip->i_depth)
+				revokes += sdp->sd_inptrs;
+			ret = gfs2_trans_begin(sdp, jblocks_rqsted, revokes);
+			if (ret)
+				goto out_unlock;
+			down_write(&ip->i_rw_mutex);
+		}
+		/* check if we will exceed the transaction blocks requested */
+		tr = current->journal_info;
+		if (tr->tr_num_buf_new + RES_STATFS +
+		    RES_QUOTA >= atomic_read(&sdp->sd_log_thresh2)) {
+			/* We set blks_outside_rgrp to ensure the loop will
+			   be repeated for the same rgrp, but with a new
+			   transaction. */
+			blks_outside_rgrp++;
+			/* This next part is tricky. If the buffer was added
+			   to the transaction, we've already set some block
+			   pointers to 0, so we better follow through and free
+			   them, or we will introduce corruption (so break).
+			   This may be impossible, or at least rare, but I
+			   decided to cover the case regardless.
+
+			   If the buffer was not added to the transaction
+			   (this call), doing so would exceed our transaction
+			   size, so we need to end the transaction and start a
+			   new one (so goto). */
+
+			if (buf_in_tr)
+				break;
+			goto out_unlock;
+		}
+
+		gfs2_trans_add_meta(ip->i_gl, bh);
+		buf_in_tr = true;
+		*p = 0;
+		if (bstart + blen == bn) {
+			blen++;
+			continue;
+		}
+		if (bstart) {
+			__gfs2_free_blocks(ip, bstart, (u32)blen, meta);
+			(*btotal) += blen;
+			gfs2_add_inode_blocks(&ip->i_inode, -blen);
+		}
+		bstart = bn;
+		blen = 1;
+	}
+	if (bstart) {
+		__gfs2_free_blocks(ip, bstart, (u32)blen, meta);
+		(*btotal) += blen;
+		gfs2_add_inode_blocks(&ip->i_inode, -blen);
+	}
+out_unlock:
+	if (!ret && blks_outside_rgrp) { /* If buffer still has non-zero blocks
+					    outside the rgrp we just processed,
+					    do it all over again. */
+		if (current->journal_info) {
+			struct buffer_head *dibh = mp->mp_bh[0];
+
+			/* Every transaction boundary, we rewrite the dinode
+			   to keep its di_blocks current in case of failure. */
+			ip->i_inode.i_mtime = ip->i_inode.i_ctime =
+				CURRENT_TIME;
+			gfs2_trans_add_meta(ip->i_gl, dibh);
+			gfs2_dinode_out(ip, dibh->b_data);
+			up_write(&ip->i_rw_mutex);
+			gfs2_trans_end(sdp);
+		}
+		gfs2_glock_dq_uninit(rd_gh);
+		cond_resched();
+		goto more_rgrps;
+	}
+out:
+	return ret;
+}
+
+/**
+ * find_nonnull_ptr - find a non-null pointer given a metapath and height
+ * assumes the metapath is valid (with buffers) out to height h
+ * @mp: starting metapath
+ * @h: desired height to search
+ *
+ * Returns: true if a non-null pointer was found in the metapath buffer
+ *          false if all remaining pointers are NULL in the buffer
+ */
+static bool find_nonnull_ptr(struct gfs2_sbd *sdp, struct metapath *mp,
+			     unsigned int h)
+{
+	__be64 *ptr;
+	unsigned int ptrs = hptrs(sdp, h) - 1;
+
+	while (true) {
+		ptr = metapointer(h, mp);
+		if (*ptr) /* if we have a non-null pointer */
+			return true;
+
+		if (mp->mp_list[h] < ptrs)
+			mp->mp_list[h]++;
+		else
+			return false; /* no more pointers in this buffer */
+	}
+}
+
+enum dealloc_states {
+	DEALLOC_MP_FULL = 0,    /* Strip a metapath with all buffers read in */
+	DEALLOC_MP_LOWER = 1,   /* lower the metapath strip height */
+	DEALLOC_FILL_MP = 2,  /* Fill in the metapath to the given height. */
+	DEALLOC_DONE = 3,       /* process complete */
+};
+
+/**
+ * trunc_dealloc - truncate a file down to a desired size
+ * @ip: inode to truncate
+ * @newsize: The desired size of the file
+ *
+ * This function truncates a file to newsize. It works from the
+ * bottom up, and from the right to the left. In other words, it strips off
+ * the highest layer (data) before stripping any of the metadata. Doing it
+ * this way is best in case the operation is interrupted by power failure, etc.
+ * The dinode is rewritten in every transaction to guarantee integrity.
+ */
+static int trunc_dealloc(struct gfs2_inode *ip, u64 newsize)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct metapath mp;
+	struct buffer_head *dibh, *bh;
+	struct gfs2_holder rd_gh;
+	u64 lblock;
+	__u16 nbof[GFS2_MAX_META_HEIGHT]; /* new beginning of truncation */
+	unsigned int strip_h = ip->i_height - 1;
+	u32 btotal = 0;
+	int ret, state;
+	int mp_h; /* metapath buffers are read in to this height */
+	sector_t last_ra = 0;
+	u64 prev_bnr = 0;
+	bool preserve1; /* need to preserve the first meta pointer? */
+
+	if (!newsize)
 		lblock = 0;
 	else
-		lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift;
+		lblock = (newsize - 1) >> sdp->sd_sb.sb_bsize_shift;
 
+	memset(&mp, 0, sizeof(mp));
 	find_metapath(sdp, lblock, &mp, ip->i_height);
-	error = gfs2_rindex_update(sdp);
-	if (error)
-		return error;
 
-	error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
-	if (error)
-		return error;
+	memcpy(&nbof, &mp.mp_list, sizeof(nbof));
 
-	while (height--) {
-		struct strip_mine sm;
-		sm.sm_first = !!size;
-		sm.sm_height = height;
+	ret = gfs2_meta_inode_buffer(ip, &dibh);
+	if (ret)
+		return ret;
 
-		error = recursive_scan(ip, NULL, &mp, 0, 0, 1, &sm);
-		if (error)
+	mp.mp_bh[0] = dibh;
+	ret = lookup_metapath(ip, &mp);
+	if (ret == ip->i_height)
+		state = DEALLOC_MP_FULL; /* We have a complete metapath */
+	else
+		state = DEALLOC_FILL_MP; /* deal with partial metapath */
+
+	ret = gfs2_rindex_update(sdp);
+	if (ret)
+		goto out_metapath;
+
+	ret = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
+	if (ret)
+		goto out_metapath;
+	gfs2_holder_mark_uninitialized(&rd_gh);
+
+	mp_h = strip_h;
+
+	while (state != DEALLOC_DONE) {
+		switch (state) {
+		/* Truncate a full metapath at the given strip height.
+		 * Note that strip_h == mp_h in order to be in this state. */
+		case DEALLOC_MP_FULL:
+			if (mp_h > 0) { /* issue read-ahead on metadata */
+				__be64 *top;
+
+				bh = mp.mp_bh[mp_h - 1];
+				if (bh->b_blocknr != last_ra) {
+					last_ra = bh->b_blocknr;
+					top = metaptr1(mp_h - 1, &mp);
+					gfs2_metapath_ra(ip->i_gl, bh, top);
+				}
+			}
+			/* If we're truncating to a non-zero size and the mp is
+			   at the beginning of file for the strip height, we
+			   need to preserve the first metadata pointer. */
+			preserve1 = (newsize &&
+				     (mp.mp_list[mp_h] == nbof[mp_h]));
+			bh = mp.mp_bh[mp_h];
+			gfs2_assert_withdraw(sdp, bh);
+			if (gfs2_assert_withdraw(sdp,
+						 prev_bnr != bh->b_blocknr)) {
+				printk(KERN_EMERG "GFS2: fsid=%s:inode %llu, "
+				       "block:%llu, i_h:%u, s_h:%u, mp_h:%u\n",
+				       sdp->sd_fsname,
+				       (unsigned long long)ip->i_no_addr,
+				       prev_bnr, ip->i_height, strip_h, mp_h);
+			}
+			prev_bnr = bh->b_blocknr;
+			ret = sweep_bh_for_rgrps(ip, &rd_gh, &mp, &btotal,
+						 mp_h, preserve1);
+			/* If we hit an error or just swept dinode buffer,
+			   just exit. */
+			if (ret || !mp_h) {
+				state = DEALLOC_DONE;
+				break;
+			}
+			state = DEALLOC_MP_LOWER;
 			break;
+
+		/* lower the metapath strip height */
+		case DEALLOC_MP_LOWER:
+			/* We're done with the current buffer, so release it,
+			   unless it's the dinode buffer. Then back up to the
+			   previous pointer. */
+			if (mp_h) {
+				brelse(mp.mp_bh[mp_h]);
+				mp.mp_bh[mp_h] = NULL;
+			}
+			/* If we can't get any lower in height, we've stripped
+			   off all we can. Next step is to back up and start
+			   stripping the previous level of metadata. */
+			if (mp_h == 0) {
+				strip_h--;
+				memcpy(&mp.mp_list, &nbof, sizeof(nbof));
+				mp_h = strip_h;
+				state = DEALLOC_FILL_MP;
+				break;
+			}
+			mp.mp_list[mp_h] = 0;
+			mp_h--; /* search one metadata height down */
+			if (mp.mp_list[mp_h] >= hptrs(sdp, mp_h) - 1)
+				break; /* loop around in the same state */
+			mp.mp_list[mp_h]++;
+			/* Here we've found a part of the metapath that is not
+			 * allocated. We need to search at that height for the
+			 * next non-null pointer. */
+			if (find_nonnull_ptr(sdp, &mp, mp_h)) {
+				state = DEALLOC_FILL_MP;
+				mp_h++;
+			}
+			/* No more non-null pointers at this height. Back up
+			   to the previous height and try again. */
+			break; /* loop around in the same state */
+
+		/* Fill the metapath with buffers to the given height. */
+		case DEALLOC_FILL_MP:
+			/* Fill the buffers out to the current height. */
+			ret = fillup_metapath(ip, &mp, mp_h);
+			if (ret < 0)
+				goto out;
+
+			/* If buffers found for the entire strip height */
+			if ((ret == ip->i_height) && (mp_h == strip_h)) {
+				state = DEALLOC_MP_FULL;
+				break;
+			}
+			if (ret < ip->i_height) /* We have a partial height */
+				mp_h = ret - 1;
+
+			/* If we find a non-null block pointer, crawl a bit
+			   higher up in the metapath and try again, otherwise
+			   we need to look lower for a new starting point. */
+			if (find_nonnull_ptr(sdp, &mp, mp_h))
+				mp_h++;
+			else
+				state = DEALLOC_MP_LOWER;
+			break;
+		}
 	}
 
-	gfs2_quota_unhold(ip);
+	if (btotal) {
+		if (current->journal_info == NULL) {
+			ret = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS +
+					       RES_QUOTA, 0);
+			if (ret)
+				goto out;
+			down_write(&ip->i_rw_mutex);
+		}
+		gfs2_statfs_change(sdp, 0, +btotal, 0);
+		gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
+				  ip->i_inode.i_gid);
+		ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
+		gfs2_trans_add_meta(ip->i_gl, dibh);
+		gfs2_dinode_out(ip, dibh->b_data);
+		up_write(&ip->i_rw_mutex);
+		gfs2_trans_end(sdp);
+	}
 
-	return error;
+out:
+	if (gfs2_holder_initialized(&rd_gh))
+		gfs2_glock_dq_uninit(&rd_gh);
+	if (current->journal_info) {
+		up_write(&ip->i_rw_mutex);
+		gfs2_trans_end(sdp);
+		cond_resched();
+	}
+	gfs2_quota_unhold(ip);
+out_metapath:
+	release_metapath(&mp);
+	return ret;
 }
 
 static int trunc_end(struct gfs2_inode *ip)
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 86ccc0159393..83c9909ff14a 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -483,13 +483,6 @@ void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
 	}
 }
 
-static inline int rgrp_contains_block(struct gfs2_rgrpd *rgd, u64 block)
-{
-	u64 first = rgd->rd_data0;
-	u64 last = first + rgd->rd_data;
-	return first <= block && block < last;
-}
-
 /**
  * gfs2_blk2rgrpd - Find resource group for a given data/meta block number
  * @sdp: The GFS2 superblock
diff --git a/fs/gfs2/rgrp.h b/fs/gfs2/rgrp.h
index 66b51cf66dfa..e90478e2f545 100644
--- a/fs/gfs2/rgrp.h
+++ b/fs/gfs2/rgrp.h
@@ -83,5 +83,12 @@ static inline bool gfs2_rs_active(const struct gfs2_blkreserv *rs)
 	return rs && !RB_EMPTY_NODE(&rs->rs_node);
 }
 
+static inline int rgrp_contains_block(struct gfs2_rgrpd *rgd, u64 block)
+{
+	u64 first = rgd->rd_data0;
+	u64 last = first + rgd->rd_data;
+	return first <= block && block < last;
+}
+
 extern void check_and_update_goal(struct gfs2_inode *ip);
 #endif /* __RGRP_DOT_H__ */