[PATCH 08/16] GFS2: Resource group code

[PATCH 08/16] GFS2: Resource group code

[Steven Whitehouse]

[PATCH 08/16] GFS2: Resource group code

GFS2's resource group handling code and code for manipulating bitmaps.


Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>


 fs/gfs2/bits.c |  182 +++++++
 fs/gfs2/bits.h |   28 +
 fs/gfs2/rgrp.c | 1369 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/gfs2/rgrp.h |   62 ++
 4 files changed, 1641 insertions(+)

--- /dev/null
+++ b/fs/gfs2/rgrp.c
@@ -0,0 +1,1369 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/gfs2_ondisk.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
+#include "bits.h"
+#include "glock.h"
+#include "glops.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "super.h"
+#include "trans.h"
+#include "ops_file.h"
+#include "util.h"
+
+/**
+ * gfs2_rgrp_verify - Verify that a resource group is consistent
+ * @sdp: the filesystem
+ * @rgd: the rgrp
+ *
+ */
+
+void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length = rgd->rd_ri.ri_length;
+	uint32_t count[4], tmp;
+	int buf, x;
+
+	memset(count, 0, 4 * sizeof(uint32_t));
+
+	/* Count # blocks in each of 4 possible allocation states */
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		for (x = 0; x < 4; x++)
+			count[x] += gfs2_bitcount(rgd,
+						  bi->bi_bh->b_data +
+						  bi->bi_offset,
+						  bi->bi_len, x);
+	}
+
+	if (count[0] != rgd->rd_rg.rg_free) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "free data mismatch:  %u != %u\n",
+			       count[0], rgd->rd_rg.rg_free);
+		return;
+	}
+
+	tmp = rgd->rd_ri.ri_data -
+		rgd->rd_rg.rg_free -
+		rgd->rd_rg.rg_dinodes;
+	if (count[1] != tmp) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "used data mismatch:  %u != %u\n",
+			       count[1], tmp);
+		return;
+	}
+
+	if (count[2]) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "free metadata mismatch:  %u != 0\n",
+			       count[2]);
+		return;
+	}
+
+	if (count[3] != rgd->rd_rg.rg_dinodes) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "used metadata mismatch:  %u != %u\n",
+			       count[3], rgd->rd_rg.rg_dinodes);
+		return;
+	}
+}
+
+static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block)
+{
+	uint64_t first = ri->ri_data0;
+	uint64_t last = first + ri->ri_data;
+	return !!(first <= block && block < last);
+}
+
+/**
+ * gfs2_blk2rgrpd - Find resource group for a given data/meta block number
+ * @sdp: The GFS2 superblock
+ * @n: The data block number
+ *
+ * Returns: The resource group, or NULL if not found
+ */
+
+struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk)
+{
+	struct gfs2_rgrpd *rgd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_mru_list, rd_list_mru) {
+		if (rgrp_contains_block(&rgd->rd_ri, blk)) {
+			list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
+			spin_unlock(&sdp->sd_rindex_spin);
+			return rgd;
+		}
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return NULL;
+}
+
+/**
+ * gfs2_rgrpd_get_first - get the first Resource Group in the filesystem
+ * @sdp: The GFS2 superblock
+ *
+ * Returns: The first rgrp in the filesystem
+ */
+
+struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp)
+{
+	gfs2_assert(sdp, !list_empty(&sdp->sd_rindex_list));
+	return list_entry(sdp->sd_rindex_list.next, struct gfs2_rgrpd, rd_list);
+}
+
+/**
+ * gfs2_rgrpd_get_next - get the next RG
+ * @rgd: A RG
+ *
+ * Returns: The next rgrp
+ */
+
+struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd)
+{
+	if (rgd->rd_list.next == &rgd->rd_sbd->sd_rindex_list)
+		return NULL;
+	return list_entry(rgd->rd_list.next, struct gfs2_rgrpd, rd_list);
+}
+
+static void clear_rgrpdi(struct gfs2_sbd *sdp)
+{
+	struct list_head *head;
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_glock *gl;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	sdp->sd_rindex_forward = NULL;
+	head = &sdp->sd_rindex_recent_list;
+	while (!list_empty(head)) {
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
+		list_del(&rgd->rd_recent);
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	head = &sdp->sd_rindex_list;
+	while (!list_empty(head)) {
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_list);
+		gl = rgd->rd_gl;
+
+		list_del(&rgd->rd_list);
+		list_del(&rgd->rd_list_mru);
+
+		if (gl) {
+			gl->gl_object = NULL;
+			gfs2_glock_put(gl);
+		}
+
+		kfree(rgd->rd_bits);
+		kfree(rgd);
+	}
+}
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
+{
+	mutex_lock(&sdp->sd_rindex_mutex);
+	clear_rgrpdi(sdp);
+	mutex_unlock(&sdp->sd_rindex_mutex);
+}
+
+/**
+ * gfs2_compute_bitstructs - Compute the bitmap sizes
+ * @rgd: The resource group descriptor
+ *
+ * Calculates bitmap descriptors, one for each block that contains bitmap data
+ *
+ * Returns: errno
+ */
+
+static int compute_bitstructs(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_bitmap *bi;
+	uint32_t length = rgd->rd_ri.ri_length; /* # blocks in hdr & bitmap */
+	uint32_t bytes_left, bytes;
+	int x;
+
+	rgd->rd_bits = kcalloc(length, sizeof(struct gfs2_bitmap), GFP_KERNEL);
+	if (!rgd->rd_bits)
+		return -ENOMEM;
+
+	bytes_left = rgd->rd_ri.ri_bitbytes;
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+
+		/* small rgrp; bitmap stored completely in header block */
+		if (length == 1) {
+			bytes = bytes_left;
+			bi->bi_offset = sizeof(struct gfs2_rgrp);
+			bi->bi_start = 0;
+			bi->bi_len = bytes;
+		/* header block */
+		} else if (x == 0) {
+			bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_rgrp);
+			bi->bi_offset = sizeof(struct gfs2_rgrp);
+			bi->bi_start = 0;
+			bi->bi_len = bytes;
+		/* last block */
+		} else if (x + 1 == length) {
+			bytes = bytes_left;
+			bi->bi_offset = sizeof(struct gfs2_meta_header);
+			bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
+			bi->bi_len = bytes;
+		/* other blocks */
+		} else {
+			bytes = sdp->sd_sb.sb_bsize -
+				sizeof(struct gfs2_meta_header);
+			bi->bi_offset = sizeof(struct gfs2_meta_header);
+			bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
+			bi->bi_len = bytes;
+		}
+
+		bytes_left -= bytes;
+	}
+
+	if (bytes_left) {
+		gfs2_consist_rgrpd(rgd);
+		return -EIO;
+	}
+	bi = rgd->rd_bits + (length - 1);
+	if ((bi->bi_start + bi->bi_len) * GFS2_NBBY != rgd->rd_ri.ri_data) {
+		if (gfs2_consist_rgrpd(rgd)) {
+			gfs2_rindex_print(&rgd->rd_ri);
+			fs_err(sdp, "start=%u len=%u offset=%u\n",
+			       bi->bi_start, bi->bi_len, bi->bi_offset);
+		}
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_ri_update - Pull in a new resource index from the disk
+ * @gl: The glock covering the rindex inode
+ *
+ * Returns: 0 on successful update, error code otherwise
+ */
+
+static int gfs2_ri_update(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct inode *inode = ip->i_vnode;
+	struct gfs2_rgrpd *rgd;
+	char buf[sizeof(struct gfs2_rindex)];
+	struct file_ra_state ra_state;
+	uint64_t junk = ip->i_di.di_size;
+	int error;
+
+	if (do_div(junk, sizeof(struct gfs2_rindex))) {
+		gfs2_consist_inode(ip);
+		return -EIO;
+	}
+
+	clear_rgrpdi(sdp);
+
+	file_ra_state_init(&ra_state, inode->i_mapping);
+	for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
+		loff_t pos = sdp->sd_rgrps * sizeof(struct gfs2_rindex);
+		error = gfs2_internal_read(ip, &ra_state, buf, &pos,
+					    sizeof(struct gfs2_rindex));
+		if (!error)
+			break;
+		if (error != sizeof(struct gfs2_rindex)) {
+			if (error > 0)
+				error = -EIO;
+			goto fail;
+		}
+
+		rgd = kzalloc(sizeof(struct gfs2_rgrpd), GFP_KERNEL);
+		error = -ENOMEM;
+		if (!rgd)
+			goto fail;
+
+		mutex_init(&rgd->rd_mutex);
+		lops_init_le(&rgd->rd_le, &gfs2_rg_lops);
+		rgd->rd_sbd = sdp;
+
+		list_add_tail(&rgd->rd_list, &sdp->sd_rindex_list);
+		list_add_tail(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
+
+		gfs2_rindex_in(&rgd->rd_ri, buf);
+
+		error = compute_bitstructs(rgd);
+		if (error)
+			goto fail;
+
+		error = gfs2_glock_get(sdp, rgd->rd_ri.ri_addr,
+				       &gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
+		if (error)
+			goto fail;
+
+		rgd->rd_gl->gl_object = rgd;
+		rgd->rd_rg_vn = rgd->rd_gl->gl_vn - 1;
+	}
+
+	sdp->sd_rindex_vn = ip->i_gl->gl_vn;
+
+	return 0;
+
+ fail:
+	clear_rgrpdi(sdp);
+
+	return error;
+}
+
+/**
+ * gfs2_rindex_hold - Grab a lock on the rindex
+ * @sdp: The GFS2 superblock
+ * @ri_gh: the glock holder
+ *
+ * We grab a lock on the rindex inode to make sure that it doesn't
+ * change whilst we are performing an operation. We keep this lock
+ * for quite long periods of time compared to other locks. This
+ * doesn't matter, since it is shared and it is very, very rarely
+ * accessed in the exclusive mode (i.e. only when expanding the filesystem).
+ *
+ * This makes sure that we're using the latest copy of the resource index
+ * special file, which might have been updated if someone expanded the
+ * filesystem (via gfs2_grow utility), which adds new resource groups.
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh)
+{
+	struct gfs2_inode *ip = sdp->sd_rindex->u.generic_ip;
+	struct gfs2_glock *gl = ip->i_gl;
+	int error;
+
+	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, ri_gh);
+	if (error)
+		return error;
+
+	/* Read new copy from disk if we don't have the latest */
+	if (sdp->sd_rindex_vn != gl->gl_vn) {
+		mutex_lock(&sdp->sd_rindex_mutex);
+		if (sdp->sd_rindex_vn != gl->gl_vn) {
+			error = gfs2_ri_update(ip);
+			if (error)
+				gfs2_glock_dq_uninit(ri_gh);
+		}
+		mutex_unlock(&sdp->sd_rindex_mutex);
+	}
+
+	return error;
+}
+
+/**
+ * gfs2_rgrp_bh_get - Read in a RG's header and bitmaps
+ * @rgd: the struct gfs2_rgrpd describing the RG to read in
+ *
+ * Read in all of a Resource Group's header and bitmap blocks.
+ * Caller must eventually call gfs2_rgrp_relse() to free the bitmaps.
+ *
+ * Returns: errno
+ */
+
+int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_glock *gl = rgd->rd_gl;
+	unsigned int length = rgd->rd_ri.ri_length;
+	struct gfs2_bitmap *bi;
+	unsigned int x, y;
+	int error;
+
+	mutex_lock(&rgd->rd_mutex);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	if (rgd->rd_bh_count) {
+		rgd->rd_bh_count++;
+		spin_unlock(&sdp->sd_rindex_spin);
+		mutex_unlock(&rgd->rd_mutex);
+		return 0;
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+		error = gfs2_meta_read(gl, rgd->rd_ri.ri_addr + x, DIO_START,
+				       &bi->bi_bh);
+		if (error)
+			goto fail;
+	}
+
+	for (y = length; y--;) {
+		bi = rgd->rd_bits + y;
+		error = gfs2_meta_reread(sdp, bi->bi_bh, DIO_WAIT);
+		if (error)
+			goto fail;
+		if (gfs2_metatype_check(sdp, bi->bi_bh,
+					(y) ? GFS2_METATYPE_RB :
+					      GFS2_METATYPE_RG)) {
+			error = -EIO;
+			goto fail;
+		}
+	}
+
+	if (rgd->rd_rg_vn != gl->gl_vn) {
+		gfs2_rgrp_in(&rgd->rd_rg, (rgd->rd_bits[0].bi_bh)->b_data);
+		rgd->rd_rg_vn = gl->gl_vn;
+	}
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone = rgd->rd_rg.rg_free;
+	rgd->rd_bh_count++;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	mutex_unlock(&rgd->rd_mutex);
+
+	return 0;
+
+ fail:
+	while (x--) {
+		bi = rgd->rd_bits + x;
+		brelse(bi->bi_bh);
+		bi->bi_bh = NULL;
+		gfs2_assert_warn(sdp, !bi->bi_clone);
+	}
+	mutex_unlock(&rgd->rd_mutex);
+
+	return error;
+}
+
+void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
+	rgd->rd_bh_count++;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * gfs2_rgrp_bh_put - Release RG bitmaps read in with gfs2_rgrp_bh_get()
+ * @rgd: the struct gfs2_rgrpd describing the RG to read in
+ *
+ */
+
+void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	int x, length = rgd->rd_ri.ri_length;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
+	if (--rgd->rd_bh_count) {
+		spin_unlock(&sdp->sd_rindex_spin);
+		return;
+	}
+
+	for (x = 0; x < length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		kfree(bi->bi_clone);
+		bi->bi_clone = NULL;
+		brelse(bi->bi_bh);
+		bi->bi_bh = NULL;
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	unsigned int length = rgd->rd_ri.ri_length;
+	unsigned int x;
+
+	for (x = 0; x < length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		if (!bi->bi_clone)
+			continue;
+		memcpy(bi->bi_clone + bi->bi_offset,
+		       bi->bi_bh->b_data + bi->bi_offset,
+		       bi->bi_len);
+	}
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone = rgd->rd_rg.rg_free;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * gfs2_alloc_get - get the struct gfs2_alloc structure for an inode
+ * @ip: the incore GFS2 inode structure
+ *
+ * Returns: the struct gfs2_alloc
+ */
+
+struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip)
+{
+	struct gfs2_alloc *al = &ip->i_alloc;
+
+	/* FIXME: Should assert that the correct locks are held here... */
+	memset(al, 0, sizeof(*al));
+	return al;
+}
+
+/**
+ * gfs2_alloc_put - throw away the struct gfs2_alloc for an inode
+ * @ip: the inode
+ *
+ */
+
+void gfs2_alloc_put(struct gfs2_inode *ip)
+{
+	return;
+}
+
+/**
+ * try_rgrp_fit - See if a given reservation will fit in a given RG
+ * @rgd: the RG data
+ * @al: the struct gfs2_alloc structure describing the reservation
+ *
+ * If there's room for the requested blocks to be allocated from the RG:
+ *   Sets the $al_reserved_data field in @al.
+ *   Sets the $al_reserved_meta field in @al.
+ *   Sets the $al_rgd field in @al.
+ *
+ * Returns: 1 on success (it fits), 0 on failure (it doesn't fit)
+ */
+
+static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	int ret = 0;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	if (rgd->rd_free_clone >= al->al_requested) {
+		al->al_rgd = rgd;
+		ret = 1;
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return ret;
+}
+
+/**
+ * recent_rgrp_first - get first RG from "recent" list
+ * @sdp: The GFS2 superblock
+ * @rglast: address of the rgrp used last
+ *
+ * Returns: The first rgrp in the recent list
+ */
+
+static struct gfs2_rgrpd *recent_rgrp_first(struct gfs2_sbd *sdp,
+					    uint64_t rglast)
+{
+	struct gfs2_rgrpd *rgd = NULL;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	if (list_empty(&sdp->sd_rindex_recent_list))
+		goto out;
+
+	if (!rglast)
+		goto first;
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
+		if (rgd->rd_ri.ri_addr == rglast)
+			goto out;
+	}
+
+ first:
+	rgd = list_entry(sdp->sd_rindex_recent_list.next, struct gfs2_rgrpd,
+			 rd_recent);
+
+ out:
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return rgd;
+}
+
+/**
+ * recent_rgrp_next - get next RG from "recent" list
+ * @cur_rgd: current rgrp
+ * @remove:
+ *
+ * Returns: The next rgrp in the recent list
+ */
+
+static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd,
+					   int remove)
+{
+	struct gfs2_sbd *sdp = cur_rgd->rd_sbd;
+	struct list_head *head;
+	struct gfs2_rgrpd *rgd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	head = &sdp->sd_rindex_recent_list;
+
+	list_for_each_entry(rgd, head, rd_recent) {
+		if (rgd == cur_rgd) {
+			if (cur_rgd->rd_recent.next != head)
+				rgd = list_entry(cur_rgd->rd_recent.next,
+						 struct gfs2_rgrpd, rd_recent);
+			else
+				rgd = NULL;
+
+			if (remove)
+				list_del(&cur_rgd->rd_recent);
+
+			goto out;
+		}
+	}
+
+	rgd = NULL;
+	if (!list_empty(head))
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
+
+ out:
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return rgd;
+}
+
+/**
+ * recent_rgrp_add - add an RG to tail of "recent" list
+ * @new_rgd: The rgrp to add
+ *
+ */
+
+static void recent_rgrp_add(struct gfs2_rgrpd *new_rgd)
+{
+	struct gfs2_sbd *sdp = new_rgd->rd_sbd;
+	struct gfs2_rgrpd *rgd;
+	unsigned int count = 0;
+	unsigned int max = sdp->sd_rgrps / gfs2_jindex_size(sdp);
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
+		if (rgd == new_rgd)
+			goto out;
+
+		if (++count >= max)
+			goto out;
+	}
+	list_add_tail(&new_rgd->rd_recent, &sdp->sd_rindex_recent_list);
+
+ out:
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * forward_rgrp_get - get an rgrp to try next from full list
+ * @sdp: The GFS2 superblock
+ *
+ * Returns: The rgrp to try next
+ */
+
+static struct gfs2_rgrpd *forward_rgrp_get(struct gfs2_sbd *sdp)
+{
+	struct gfs2_rgrpd *rgd;
+	unsigned int journals = gfs2_jindex_size(sdp);
+	unsigned int rg = 0, x;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	rgd = sdp->sd_rindex_forward;
+	if (!rgd) {
+		if (sdp->sd_rgrps >= journals)
+			rg = sdp->sd_rgrps * sdp->sd_jdesc->jd_jid / journals;
+
+		for (x = 0, rgd = gfs2_rgrpd_get_first(sdp);
+		     x < rg;
+		     x++, rgd = gfs2_rgrpd_get_next(rgd))
+			/* Do Nothing */;
+
+		sdp->sd_rindex_forward = rgd;
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return rgd;
+}
+
+/**
+ * forward_rgrp_set - set the forward rgrp pointer
+ * @sdp: the filesystem
+ * @rgd: The new forward rgrp
+ *
+ */
+
+static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd)
+{
+	spin_lock(&sdp->sd_rindex_spin);
+	sdp->sd_rindex_forward = rgd;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * get_local_rgrp - Choose and lock a rgrp for allocation
+ * @ip: the inode to reserve space for
+ * @rgp: the chosen and locked rgrp
+ *
+ * Try to acquire rgrp in way which avoids contending with others.
+ *
+ * Returns: errno
+ */
+
+static int get_local_rgrp(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_rgrpd *rgd, *begin = NULL;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	int flags = LM_FLAG_TRY;
+	int skipped = 0;
+	int loops = 0;
+	int error;
+
+	/* Try recently successful rgrps */
+
+	rgd = recent_rgrp_first(sdp, ip->i_last_rg_alloc);
+
+	while (rgd) {
+		error = gfs2_glock_nq_init(rgd->rd_gl,
+					  LM_ST_EXCLUSIVE, LM_FLAG_TRY,
+					  &al->al_rgd_gh);
+		switch (error) {
+		case 0:
+			if (try_rgrp_fit(rgd, al))
+				goto out;
+			gfs2_glock_dq_uninit(&al->al_rgd_gh);
+			rgd = recent_rgrp_next(rgd, 1);
+			break;
+
+		case GLR_TRYFAILED:
+			rgd = recent_rgrp_next(rgd, 0);
+			break;
+
+		default:
+			return error;
+		}
+	}
+
+	/* Go through full list of rgrps */
+
+	begin = rgd = forward_rgrp_get(sdp);
+
+	for (;;) {
+		error = gfs2_glock_nq_init(rgd->rd_gl,
+					  LM_ST_EXCLUSIVE, flags,
+					  &al->al_rgd_gh);
+		switch (error) {
+		case 0:
+			if (try_rgrp_fit(rgd, al))
+				goto out;
+			gfs2_glock_dq_uninit(&al->al_rgd_gh);
+			break;
+
+		case GLR_TRYFAILED:
+			skipped++;
+			break;
+
+		default:
+			return error;
+		}
+
+		rgd = gfs2_rgrpd_get_next(rgd);
+		if (!rgd)
+			rgd = gfs2_rgrpd_get_first(sdp);
+
+		if (rgd == begin) {
+			if (++loops >= 2 || !skipped)
+				return -ENOSPC;
+			flags = 0;
+		}
+	}
+
+ out:
+	ip->i_last_rg_alloc = rgd->rd_ri.ri_addr;
+
+	if (begin) {
+		recent_rgrp_add(rgd);
+		rgd = gfs2_rgrpd_get_next(rgd);
+		if (!rgd)
+			rgd = gfs2_rgrpd_get_first(sdp);
+		forward_rgrp_set(sdp, rgd);
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_inplace_reserve_i - Reserve space in the filesystem
+ * @ip: the inode to reserve space for
+ *
+ * Returns: errno
+ */
+
+int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	int error;
+
+	if (gfs2_assert_warn(sdp, al->al_requested))
+		return -EINVAL;
+
+	error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
+	if (error)
+		return error;
+
+	error = get_local_rgrp(ip);
+	if (error) {
+		gfs2_glock_dq_uninit(&al->al_ri_gh);
+		return error;
+	}
+
+	al->al_file = file;
+	al->al_line = line;
+
+	return 0;
+}
+
+/**
+ * gfs2_inplace_release - release an inplace reservation
+ * @ip: the inode the reservation was taken out on
+ *
+ * Release a reservation made by gfs2_inplace_reserve().
+ */
+
+void gfs2_inplace_release(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_alloc *al = &ip->i_alloc;
+
+	if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1)
+		fs_warn(sdp, "al_alloced = %u, al_requested = %u "
+			     "al_file = %s, al_line = %u\n",
+		             al->al_alloced, al->al_requested, al->al_file,
+			     al->al_line);
+
+	al->al_rgd = NULL;
+	gfs2_glock_dq_uninit(&al->al_rgd_gh);
+	gfs2_glock_dq_uninit(&al->al_ri_gh);
+}
+
+/**
+ * gfs2_get_block_type - Check a block in a RG is of given type
+ * @rgd: the resource group holding the block
+ * @block: the block number
+ *
+ * Returns: The block type (GFS2_BLKST_*)
+ */
+
+unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block)
+{
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length, rgrp_block, buf_block;
+	unsigned int buf;
+	unsigned char type;
+
+	length = rgd->rd_ri.ri_length;
+	rgrp_block = block - rgd->rd_ri.ri_data0;
+
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		if (rgrp_block < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+			break;
+	}
+
+	gfs2_assert(rgd->rd_sbd, buf < length);
+	buf_block = rgrp_block - bi->bi_start * GFS2_NBBY;
+
+	type = gfs2_testbit(rgd,
+			   bi->bi_bh->b_data + bi->bi_offset,
+			   bi->bi_len, buf_block);
+
+	return type;
+}
+
+/**
+ * rgblk_search - find a block in @old_state, change allocation
+ *           state to @new_state
+ * @rgd: the resource group descriptor
+ * @goal: the goal block within the RG (start here to search for avail block)
+ * @old_state: GFS2_BLKST_XXX the before-allocation state to find
+ * @new_state: GFS2_BLKST_XXX the after-allocation block state
+ *
+ * Walk rgrp's bitmap to find bits that represent a block in @old_state.
+ * Add the found bitmap buffer to the transaction.
+ * Set the found bits to @new_state to change block's allocation state.
+ *
+ * This function never fails, because we wouldn't call it unless we
+ * know (from reservation results, etc.) that a block is available.
+ *
+ * Scope of @goal and returned block is just within rgrp, not the whole
+ * filesystem.
+ *
+ * Returns:  the block number allocated
+ */
+
+static uint32_t rgblk_search(struct gfs2_rgrpd *rgd, uint32_t goal,
+			     unsigned char old_state, unsigned char new_state)
+{
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length = rgd->rd_ri.ri_length;
+	uint32_t blk = 0;
+	unsigned int buf, x;
+
+	/* Find bitmap block that contains bits for goal block */
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+			break;
+	}
+
+	gfs2_assert(rgd->rd_sbd, buf < length);
+
+	/* Convert scope of "goal" from rgrp-wide to within found bit block */
+	goal -= bi->bi_start * GFS2_NBBY;
+
+	/* Search (up to entire) bitmap in this rgrp for allocatable block.
+	   "x <= length", instead of "x < length", because we typically start
+	   the search in the middle of a bit block, but if we can't find an
+	   allocatable block anywhere else, we want to be able wrap around and
+	   search in the first part of our first-searched bit block.  */
+	for (x = 0; x <= length; x++) {
+		if (bi->bi_clone)
+			blk = gfs2_bitfit(rgd,
+					  bi->bi_clone + bi->bi_offset,
+					  bi->bi_len, goal, old_state);
+		else
+			blk = gfs2_bitfit(rgd,
+					  bi->bi_bh->b_data + bi->bi_offset,
+					  bi->bi_len, goal, old_state);
+		if (blk != BFITNOENT)
+			break;
+
+		/* Try next bitmap block (wrap back to rgrp header if at end) */
+		buf = (buf + 1) % length;
+		bi = rgd->rd_bits + buf;
+		goal = 0;
+	}
+
+	if (gfs2_assert_withdraw(rgd->rd_sbd, x <= length))
+		blk = 0;
+
+	gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
+	gfs2_setbit(rgd,
+		    bi->bi_bh->b_data + bi->bi_offset,
+		    bi->bi_len, blk, new_state);
+	if (bi->bi_clone)
+		gfs2_setbit(rgd,
+			    bi->bi_clone + bi->bi_offset,
+			    bi->bi_len, blk, new_state);
+
+	return bi->bi_start * GFS2_NBBY + blk;
+}
+
+/**
+ * rgblk_free - Change alloc state of given block(s)
+ * @sdp: the filesystem
+ * @bstart: the start of a run of blocks to free
+ * @blen: the length of the block run (all must lie within ONE RG!)
+ * @new_state: GFS2_BLKST_XXX the after-allocation block state
+ *
+ * Returns:  Resource group containing the block(s)
+ */
+
+static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, uint64_t bstart,
+				     uint32_t blen, unsigned char new_state)
+{
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length, rgrp_blk, buf_blk;
+	unsigned int buf;
+
+	rgd = gfs2_blk2rgrpd(sdp, bstart);
+	if (!rgd) {
+		if (gfs2_consist(sdp))
+			fs_err(sdp, "block = %llu\n", bstart);
+		return NULL;
+	}
+
+	length = rgd->rd_ri.ri_length;
+
+	rgrp_blk = bstart - rgd->rd_ri.ri_data0;
+
+	while (blen--) {
+		for (buf = 0; buf < length; buf++) {
+			bi = rgd->rd_bits + buf;
+			if (rgrp_blk < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+				break;
+		}
+
+		gfs2_assert(rgd->rd_sbd, buf < length);
+
+		buf_blk = rgrp_blk - bi->bi_start * GFS2_NBBY;
+		rgrp_blk++;
+
+		if (!bi->bi_clone) {
+			bi->bi_clone = kmalloc(bi->bi_bh->b_size,
+					       GFP_KERNEL | __GFP_NOFAIL);
+			memcpy(bi->bi_clone + bi->bi_offset,
+			       bi->bi_bh->b_data + bi->bi_offset,
+			       bi->bi_len);
+		}
+		gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
+		gfs2_setbit(rgd,
+			    bi->bi_bh->b_data + bi->bi_offset,
+			    bi->bi_len, buf_blk, new_state);
+	}
+
+	return rgd;
+}
+
+/**
+ * gfs2_alloc_data - Allocate a data block
+ * @ip: the inode to allocate the data block for
+ *
+ * Returns: the allocated block
+ */
+
+uint64_t gfs2_alloc_data(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	uint32_t goal, blk;
+	uint64_t block;
+
+	if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_data))
+		goal = ip->i_di.di_goal_data - rgd->rd_ri.ri_data0;
+	else
+		goal = rgd->rd_last_alloc_data;
+
+	blk = rgblk_search(rgd, goal,
+			   GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	rgd->rd_last_alloc_data = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+	ip->i_di.di_goal_data = block;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, 0);
+	gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_alloc_meta - Allocate a metadata block
+ * @ip: the inode to allocate the metadata block for
+ *
+ * Returns: the allocated block
+ */
+
+uint64_t gfs2_alloc_meta(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	uint32_t goal, blk;
+	uint64_t block;
+
+	if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_meta))
+		goal = ip->i_di.di_goal_meta - rgd->rd_ri.ri_data0;
+	else
+		goal = rgd->rd_last_alloc_meta;
+
+	blk = rgblk_search(rgd, goal,
+			   GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	rgd->rd_last_alloc_meta = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+	ip->i_di.di_goal_meta = block;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, 0);
+	gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_trans_add_unrevoke(sdp, block);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_alloc_di - Allocate a dinode
+ * @dip: the directory that the inode is going in
+ *
+ * Returns: the block allocated
+ */
+
+uint64_t gfs2_alloc_di(struct gfs2_inode *dip)
+{
+	struct gfs2_sbd *sdp = dip->i_sbd;
+	struct gfs2_alloc *al = &dip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	uint32_t blk;
+	uint64_t block;
+
+	blk = rgblk_search(rgd, rgd->rd_last_alloc_meta,
+			   GFS2_BLKST_FREE, GFS2_BLKST_DINODE);
+
+	rgd->rd_last_alloc_meta = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+	rgd->rd_rg.rg_dinodes++;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, +1);
+	gfs2_trans_add_unrevoke(sdp, block);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_free_data - free a contiguous run of data block(s)
+ * @ip: the inode these blocks are being freed from
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ *
+ */
+
+void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_rgrpd *rgd;
+
+	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
+	if (!rgd)
+		return;
+
+	rgd->rd_rg.rg_free += blen;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_trans_add_rg(rgd);
+
+	gfs2_statfs_change(sdp, 0, +blen, 0);
+	gfs2_quota_change(ip, -(int64_t)blen,
+			 ip->i_di.di_uid, ip->i_di.di_gid);
+}
+
+/**
+ * gfs2_free_meta - free a contiguous run of data block(s)
+ * @ip: the inode these blocks are being freed from
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ *
+ */
+
+void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct gfs2_rgrpd *rgd;
+
+	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
+	if (!rgd)
+		return;
+
+	rgd->rd_rg.rg_free += blen;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_trans_add_rg(rgd);
+
+	gfs2_statfs_change(sdp, 0, +blen, 0);
+	gfs2_quota_change(ip, -(int64_t)blen,
+			 ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_meta_wipe(ip, bstart, blen);
+}
+
+void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_rgrpd *tmp_rgd;
+
+	tmp_rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_FREE);
+	if (!tmp_rgd)
+		return;
+	gfs2_assert_withdraw(sdp, rgd == tmp_rgd);
+
+	if (!rgd->rd_rg.rg_dinodes)
+		gfs2_consist_rgrpd(rgd);
+	rgd->rd_rg.rg_dinodes--;
+	rgd->rd_rg.rg_free++;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_statfs_change(sdp, 0, +1, -1);
+	gfs2_trans_add_rg(rgd);
+}
+
+/**
+ * gfs2_free_uninit_di - free a dinode block
+ * @rgd: the resource group that contains the dinode
+ * @ip: the inode
+ *
+ */
+
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
+{
+	gfs2_free_uninit_di(rgd, ip->i_num.no_addr);
+	gfs2_quota_change(ip, -1, ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_meta_wipe(ip, ip->i_num.no_addr, 1);
+}
+
+/**
+ * gfs2_rlist_add - add a RG to a list of RGs
+ * @sdp: the filesystem
+ * @rlist: the list of resource groups
+ * @block: the block
+ *
+ * Figure out what RG a block belongs to and add that RG to the list
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
+		    uint64_t block)
+{
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_rgrpd **tmp;
+	unsigned int new_space;
+	unsigned int x;
+
+	if (gfs2_assert_warn(sdp, !rlist->rl_ghs))
+		return;
+
+	rgd = gfs2_blk2rgrpd(sdp, block);
+	if (!rgd) {
+		if (gfs2_consist(sdp))
+			fs_err(sdp, "block = %llu\n", block);
+		return;
+	}
+
+	for (x = 0; x < rlist->rl_rgrps; x++)
+		if (rlist->rl_rgd[x] == rgd)
+			return;
+
+	if (rlist->rl_rgrps == rlist->rl_space) {
+		new_space = rlist->rl_space + 10;
+
+		tmp = kcalloc(new_space, sizeof(struct gfs2_rgrpd *),
+			      GFP_KERNEL | __GFP_NOFAIL);
+
+		if (rlist->rl_rgd) {
+			memcpy(tmp, rlist->rl_rgd,
+			       rlist->rl_space * sizeof(struct gfs2_rgrpd *));
+			kfree(rlist->rl_rgd);
+		}
+
+		rlist->rl_space = new_space;
+		rlist->rl_rgd = tmp;
+	}
+
+	rlist->rl_rgd[rlist->rl_rgrps++] = rgd;
+}
+
+/**
+ * gfs2_rlist_alloc - all RGs have been added to the rlist, now allocate
+ *      and initialize an array of glock holders for them
+ * @rlist: the list of resource groups
+ * @state: the lock state to acquire the RG lock in
+ * @flags: the modifier flags for the holder structures
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
+		      int flags)
+{
+	unsigned int x;
+
+	rlist->rl_ghs = kcalloc(rlist->rl_rgrps, sizeof(struct gfs2_holder),
+				GFP_KERNEL | __GFP_NOFAIL);
+	for (x = 0; x < rlist->rl_rgrps; x++)
+		gfs2_holder_init(rlist->rl_rgd[x]->rd_gl,
+				state, flags,
+				&rlist->rl_ghs[x]);
+}
+
+/**
+ * gfs2_rlist_free - free a resource group list
+ * @list: the list of resource groups
+ *
+ */
+
+void gfs2_rlist_free(struct gfs2_rgrp_list *rlist)
+{
+	unsigned int x;
+
+	kfree(rlist->rl_rgd);
+
+	if (rlist->rl_ghs) {
+		for (x = 0; x < rlist->rl_rgrps; x++)
+			gfs2_holder_uninit(&rlist->rl_ghs[x]);
+		kfree(rlist->rl_ghs);
+	}
+}
+
--- /dev/null
+++ b/fs/gfs2/rgrp.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#ifndef __RGRP_DOT_H__
+#define __RGRP_DOT_H__
+
+void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd);
+
+struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk);
+struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp);
+struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd);
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp);
+int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh);
+
+int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd);
+void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd);
+void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd);
+
+void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd);
+
+struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip);
+void gfs2_alloc_put(struct gfs2_inode *ip);
+
+int gfs2_inplace_reserve_i(struct gfs2_inode *ip,
+			 char *file, unsigned int line);
+#define gfs2_inplace_reserve(ip) \
+gfs2_inplace_reserve_i((ip), __FILE__, __LINE__)
+
+void gfs2_inplace_release(struct gfs2_inode *ip);
+
+unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block);
+
+uint64_t gfs2_alloc_data(struct gfs2_inode *ip);
+uint64_t gfs2_alloc_meta(struct gfs2_inode *ip);
+uint64_t gfs2_alloc_di(struct gfs2_inode *ip);
+
+void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen);
+void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen);
+void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno);
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip);
+
+struct gfs2_rgrp_list {
+	unsigned int rl_rgrps;
+	unsigned int rl_space;
+	struct gfs2_rgrpd **rl_rgd;
+	struct gfs2_holder *rl_ghs;
+};
+
+void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
+		    uint64_t block);
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
+		      int flags);
+void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
+
+#endif /* __RGRP_DOT_H__ */
--- /dev/null
+++ b/fs/gfs2/bits.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+/*
+ * These routines are used by the resource group routines (rgrp.c)
+ * to keep track of block allocation.  Each block is represented by two
+ * bits.  One bit indicates whether or not the block is used.  (1=used,
+ * 0=free)  The other bit indicates whether or not the block contains a
+ * dinode or not.  (1=dinode, 0=not-dinode) So, each byte represents
+ * GFS2_NBBY (i.e. 4) blocks.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/gfs2_ondisk.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
+#include "bits.h"
+#include "util.h"
+
+static const char valid_change[16] = {
+	        /* current */
+	/* n */ 0, 1, 0, 1,
+	/* e */ 1, 0, 0, 0,
+	/* w */ 0, 0, 0, 0,
+	        1, 0, 0, 0
+};
+
+/**
+ * gfs2_setbit - Set a bit in the bitmaps
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @block: the block to set
+ * @new_state: the new state of the block
+ *
+ */
+
+void gfs2_setbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+		 unsigned int buflen, uint32_t block, unsigned char new_state)
+{
+	unsigned char *byte, *end, cur_state;
+	unsigned int bit;
+
+	byte = buffer + (block / GFS2_NBBY);
+	bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+
+	gfs2_assert(rgd->rd_sbd, byte < end);
+
+	cur_state = (*byte >> bit) & GFS2_BIT_MASK;
+
+	if (valid_change[new_state * 4 + cur_state]) {
+		*byte ^= cur_state << bit;
+		*byte |= new_state << bit;
+	} else
+		gfs2_consist_rgrpd(rgd);
+}
+
+/**
+ * gfs2_testbit - test a bit in the bitmaps
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @block: the block to read
+ *
+ */
+
+unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+			   unsigned int buflen, uint32_t block)
+{
+	unsigned char *byte, *end, cur_state;
+	unsigned int bit;
+
+	byte = buffer + (block / GFS2_NBBY);
+	bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+
+	gfs2_assert(rgd->rd_sbd, byte < end);
+
+	cur_state = (*byte >> bit) & GFS2_BIT_MASK;
+
+	return cur_state;
+}
+
+/**
+ * gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing
+ *       a block in a given allocation state.
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @goal: start search at this block's bit-pair (within @buffer)
+ * @old_state: GFS2_BLKST_XXX the state of the block we're looking for;
+ *       bit 0 = alloc(1)/free(0), bit 1 = meta(1)/data(0)
+ *
+ * Scope of @goal and returned block number is only within this bitmap buffer,
+ * not entire rgrp or filesystem.  @buffer will be offset from the actual
+ * beginning of a bitmap block buffer, skipping any header structures.
+ *
+ * Return: the block number (bitmap buffer scope) that was found
+ */
+
+uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+		     unsigned int buflen, uint32_t goal,
+		     unsigned char old_state)
+{
+	unsigned char *byte, *end, alloc;
+	uint32_t blk = goal;
+	unsigned int bit;
+
+	byte = buffer + (goal / GFS2_NBBY);
+	bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+	alloc = (old_state & 1) ? 0 : 0x55;
+
+	while (byte < end) {
+		if ((*byte & 0x55) == alloc) {
+			blk += (8 - bit) >> 1;
+
+			bit = 0;
+			byte++;
+
+			continue;
+		}
+
+		if (((*byte >> bit) & GFS2_BIT_MASK) == old_state)
+			return blk;
+
+		bit += GFS2_BIT_SIZE;
+		if (bit >= 8) {
+			bit = 0;
+			byte++;
+		}
+
+		blk++;
+	}
+
+	return BFITNOENT;
+}
+
+/**
+ * gfs2_bitcount - count the number of bits in a certain state
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @state: the state of the block we're looking for
+ *
+ * Returns: The number of bits
+ */
+
+uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+		       unsigned int buflen, unsigned char state)
+{
+	unsigned char *byte = buffer;
+	unsigned char *end = buffer + buflen;
+	unsigned char state1 = state << 2;
+	unsigned char state2 = state << 4;
+	unsigned char state3 = state << 6;
+	uint32_t count = 0;
+
+	for (; byte < end; byte++) {
+		if (((*byte) & 0x03) == state)
+			count++;
+		if (((*byte) & 0x0C) == state1)
+			count++;
+		if (((*byte) & 0x30) == state2)
+			count++;
+		if (((*byte) & 0xC0) == state3)
+			count++;
+	}
+
+	return count;
+}
+
--- /dev/null
+++ b/fs/gfs2/bits.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#ifndef __BITS_DOT_H__
+#define __BITS_DOT_H__
+
+#define BFITNOENT 0xFFFFFFFF
+
+void gfs2_setbit(struct gfs2_rgrpd *rgd,
+		unsigned char *buffer, unsigned int buflen,
+		uint32_t block, unsigned char new_state);
+unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd,
+			  unsigned char *buffer, unsigned int buflen,
+			  uint32_t block);
+uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd,
+		    unsigned char *buffer, unsigned int buflen,
+		    uint32_t goal, unsigned char old_state);
+uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd,
+		      unsigned char *buffer, unsigned int buflen,
+		      unsigned char state);
+
+#endif /* __BITS_DOT_H__ */

Re: [PATCH 08/16] GFS2: Resource group code

[Steven Whitehouse]

Hi,

On Mon, 2006-09-04 at 16:50 +0200, Jan Engelhardt wrote:
> >+#define BFITNOENT 0xFFFFFFFF
> 
> See previous mail, (uint32_t)-1 / (uint32_t)~0 or leave it.
> 
ok.

> >+static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block)
> >+{
> >+	uint64_t first = ri->ri_data0;
> >+	uint64_t last = first + ri->ri_data;
> >+	return !!(first <= block && block < last);
> >+}
> 
> No need for the !!, the expression !! is operating on is already a boolean.
> IOW,
> 
> 	return first <= block && block < last;
> 
Now fixed in:

http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=16910427e1eb2a8069708ee24406d2d465381ebd

> 
> >+/**
> >+ * gfs2_alloc_put - throw away the struct gfs2_alloc for an inode
> >+ * @ip: the inode
> >+ *
> >+ */
> >+
> >+void gfs2_alloc_put(struct gfs2_inode *ip)
> >+{
> >+	return;
> >+}
> 
> Missing some code? Code that comes later?
> 
> 
> Jan Engelhardt

Well the allocation structure used to be kmalloc'ed and free'd by this
function and gfs2_alloc_get. I changed that to put it inline in the
struct gfs2_inode since there didn't seem a lot of point in having it
dynamically allocated. I had left this function though since it was
useful to have some demarcation points in the code which showed where
the structure was in use. My plan was to later add some debugging to
detect any use outside of those points, hence, I'd left in this
function.

It could be removed now, but I'd prefer to give it a stay of execution
for a little while at least if nobody has any strong objections to that,

Steve.

Re: [PATCH 08/16] GFS2: Resource group code

[Jan Engelhardt]

>+#define BFITNOENT 0xFFFFFFFF

See previous mail, (uint32_t)-1 / (uint32_t)~0 or leave it.

>+static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block)
>+{
>+	uint64_t first = ri->ri_data0;
>+	uint64_t last = first + ri->ri_data;
>+	return !!(first <= block && block < last);
>+}

No need for the !!, the expression !! is operating on is already a boolean.
IOW,

	return first <= block && block < last;


>+/**
>+ * gfs2_alloc_put - throw away the struct gfs2_alloc for an inode
>+ * @ip: the inode
>+ *
>+ */
>+
>+void gfs2_alloc_put(struct gfs2_inode *ip)
>+{
>+	return;
>+}

Missing some code? Code that comes later?


Jan Engelhardt
-- 

[PATCH 08/16] GFS2: Resource group code

[Steven Whitehouse]

[PATCH 08/16] GFS2: Resource group code

GFS2's resource group handling code and code for manipulating bitmaps.


Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>


 fs/gfs2/rgrp.c | 1525 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/gfs2/rgrp.h |   62 ++
 2 files changed, 1587 insertions(+)

--- /dev/null
+++ b/fs/gfs2/rgrp.c
@@ -0,0 +1,1525 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/gfs2_ondisk.h>
+
+#include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
+#include "glock.h"
+#include "glops.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "super.h"
+#include "trans.h"
+#include "ops_file.h"
+#include "util.h"
+
+#define BFITNOENT 0xFFFFFFFF
+
+/*
+ * These routines are used by the resource group routines (rgrp.c)
+ * to keep track of block allocation.  Each block is represented by two
+ * bits.  So, each byte represents GFS2_NBBY (i.e. 4) blocks.
+ *
+ * 0 = Free
+ * 1 = Used (not metadata)
+ * 2 = Unlinked (still in use) inode
+ * 3 = Used (metadata)
+ */
+
+static const char valid_change[16] = {
+	        /* current */
+	/* n */ 0, 1, 1, 1,
+	/* e */ 1, 0, 0, 0,
+	/* w */ 0, 0, 0, 1,
+	        1, 0, 0, 0
+};
+
+/**
+ * gfs2_setbit - Set a bit in the bitmaps
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @block: the block to set
+ * @new_state: the new state of the block
+ *
+ */
+
+static void gfs2_setbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+			unsigned int buflen, uint32_t block,
+			unsigned char new_state)
+{
+	unsigned char *byte, *end, cur_state;
+	unsigned int bit;
+
+	byte = buffer + (block / GFS2_NBBY);
+	bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+
+	gfs2_assert(rgd->rd_sbd, byte < end);
+
+	cur_state = (*byte >> bit) & GFS2_BIT_MASK;
+
+	if (valid_change[new_state * 4 + cur_state]) {
+		*byte ^= cur_state << bit;
+		*byte |= new_state << bit;
+	} else
+		gfs2_consist_rgrpd(rgd);
+}
+
+/**
+ * gfs2_testbit - test a bit in the bitmaps
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @block: the block to read
+ *
+ */
+
+static unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+				  unsigned int buflen, uint32_t block)
+{
+	unsigned char *byte, *end, cur_state;
+	unsigned int bit;
+
+	byte = buffer + (block / GFS2_NBBY);
+	bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+
+	gfs2_assert(rgd->rd_sbd, byte < end);
+
+	cur_state = (*byte >> bit) & GFS2_BIT_MASK;
+
+	return cur_state;
+}
+
+/**
+ * gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing
+ *       a block in a given allocation state.
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @goal: start search at this block's bit-pair (within @buffer)
+ * @old_state: GFS2_BLKST_XXX the state of the block we're looking for;
+ *       bit 0 = alloc(1)/free(0), bit 1 = meta(1)/data(0)
+ *
+ * Scope of @goal and returned block number is only within this bitmap buffer,
+ * not entire rgrp or filesystem.  @buffer will be offset from the actual
+ * beginning of a bitmap block buffer, skipping any header structures.
+ *
+ * Return: the block number (bitmap buffer scope) that was found
+ */
+
+static uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+			    unsigned int buflen, uint32_t goal,
+			    unsigned char old_state)
+{
+	unsigned char *byte, *end, alloc;
+	uint32_t blk = goal;
+	unsigned int bit;
+
+	byte = buffer + (goal / GFS2_NBBY);
+	bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE;
+	end = buffer + buflen;
+	alloc = (old_state & 1) ? 0 : 0x55;
+
+	while (byte < end) {
+		if ((*byte & 0x55) == alloc) {
+			blk += (8 - bit) >> 1;
+
+			bit = 0;
+			byte++;
+
+			continue;
+		}
+
+		if (((*byte >> bit) & GFS2_BIT_MASK) == old_state)
+			return blk;
+
+		bit += GFS2_BIT_SIZE;
+		if (bit >= 8) {
+			bit = 0;
+			byte++;
+		}
+
+		blk++;
+	}
+
+	return BFITNOENT;
+}
+
+/**
+ * gfs2_bitcount - count the number of bits in a certain state
+ * @buffer: the buffer that holds the bitmaps
+ * @buflen: the length (in bytes) of the buffer
+ * @state: the state of the block we're looking for
+ *
+ * Returns: The number of bits
+ */
+
+static uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer,
+			      unsigned int buflen, unsigned char state)
+{
+	unsigned char *byte = buffer;
+	unsigned char *end = buffer + buflen;
+	unsigned char state1 = state << 2;
+	unsigned char state2 = state << 4;
+	unsigned char state3 = state << 6;
+	uint32_t count = 0;
+
+	for (; byte < end; byte++) {
+		if (((*byte) & 0x03) == state)
+			count++;
+		if (((*byte) & 0x0C) == state1)
+			count++;
+		if (((*byte) & 0x30) == state2)
+			count++;
+		if (((*byte) & 0xC0) == state3)
+			count++;
+	}
+
+	return count;
+}
+
+/**
+ * gfs2_rgrp_verify - Verify that a resource group is consistent
+ * @sdp: the filesystem
+ * @rgd: the rgrp
+ *
+ */
+
+void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length = rgd->rd_ri.ri_length;
+	uint32_t count[4], tmp;
+	int buf, x;
+
+	memset(count, 0, 4 * sizeof(uint32_t));
+
+	/* Count # blocks in each of 4 possible allocation states */
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		for (x = 0; x < 4; x++)
+			count[x] += gfs2_bitcount(rgd,
+						  bi->bi_bh->b_data +
+						  bi->bi_offset,
+						  bi->bi_len, x);
+	}
+
+	if (count[0] != rgd->rd_rg.rg_free) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "free data mismatch:  %u != %u\n",
+			       count[0], rgd->rd_rg.rg_free);
+		return;
+	}
+
+	tmp = rgd->rd_ri.ri_data -
+		rgd->rd_rg.rg_free -
+		rgd->rd_rg.rg_dinodes;
+	if (count[1] + count[2] != tmp) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "used data mismatch:  %u != %u\n",
+			       count[1], tmp);
+		return;
+	}
+
+	if (count[3] != rgd->rd_rg.rg_dinodes) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "used metadata mismatch:  %u != %u\n",
+			       count[3], rgd->rd_rg.rg_dinodes);
+		return;
+	}
+
+	if (count[2] > count[3]) {
+		if (gfs2_consist_rgrpd(rgd))
+			fs_err(sdp, "unlinked inodes > inodes:  %u\n",
+			       count[2]);
+		return;
+	}
+
+}
+
+static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block)
+{
+	uint64_t first = ri->ri_data0;
+	uint64_t last = first + ri->ri_data;
+	return !!(first <= block && block < last);
+}
+
+/**
+ * gfs2_blk2rgrpd - Find resource group for a given data/meta block number
+ * @sdp: The GFS2 superblock
+ * @n: The data block number
+ *
+ * Returns: The resource group, or NULL if not found
+ */
+
+struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk)
+{
+	struct gfs2_rgrpd *rgd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_mru_list, rd_list_mru) {
+		if (rgrp_contains_block(&rgd->rd_ri, blk)) {
+			list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
+			spin_unlock(&sdp->sd_rindex_spin);
+			return rgd;
+		}
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return NULL;
+}
+
+/**
+ * gfs2_rgrpd_get_first - get the first Resource Group in the filesystem
+ * @sdp: The GFS2 superblock
+ *
+ * Returns: The first rgrp in the filesystem
+ */
+
+struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp)
+{
+	gfs2_assert(sdp, !list_empty(&sdp->sd_rindex_list));
+	return list_entry(sdp->sd_rindex_list.next, struct gfs2_rgrpd, rd_list);
+}
+
+/**
+ * gfs2_rgrpd_get_next - get the next RG
+ * @rgd: A RG
+ *
+ * Returns: The next rgrp
+ */
+
+struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd)
+{
+	if (rgd->rd_list.next == &rgd->rd_sbd->sd_rindex_list)
+		return NULL;
+	return list_entry(rgd->rd_list.next, struct gfs2_rgrpd, rd_list);
+}
+
+static void clear_rgrpdi(struct gfs2_sbd *sdp)
+{
+	struct list_head *head;
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_glock *gl;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	sdp->sd_rindex_forward = NULL;
+	head = &sdp->sd_rindex_recent_list;
+	while (!list_empty(head)) {
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
+		list_del(&rgd->rd_recent);
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	head = &sdp->sd_rindex_list;
+	while (!list_empty(head)) {
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_list);
+		gl = rgd->rd_gl;
+
+		list_del(&rgd->rd_list);
+		list_del(&rgd->rd_list_mru);
+
+		if (gl) {
+			gl->gl_object = NULL;
+			gfs2_glock_put(gl);
+		}
+
+		kfree(rgd->rd_bits);
+		kfree(rgd);
+	}
+}
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
+{
+	mutex_lock(&sdp->sd_rindex_mutex);
+	clear_rgrpdi(sdp);
+	mutex_unlock(&sdp->sd_rindex_mutex);
+}
+
+/**
+ * gfs2_compute_bitstructs - Compute the bitmap sizes
+ * @rgd: The resource group descriptor
+ *
+ * Calculates bitmap descriptors, one for each block that contains bitmap data
+ *
+ * Returns: errno
+ */
+
+static int compute_bitstructs(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_bitmap *bi;
+	uint32_t length = rgd->rd_ri.ri_length; /* # blocks in hdr & bitmap */
+	uint32_t bytes_left, bytes;
+	int x;
+
+	if (!length)
+		return -EINVAL;
+
+	rgd->rd_bits = kcalloc(length, sizeof(struct gfs2_bitmap), GFP_NOFS);
+	if (!rgd->rd_bits)
+		return -ENOMEM;
+
+	bytes_left = rgd->rd_ri.ri_bitbytes;
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+
+		/* small rgrp; bitmap stored completely in header block */
+		if (length == 1) {
+			bytes = bytes_left;
+			bi->bi_offset = sizeof(struct gfs2_rgrp);
+			bi->bi_start = 0;
+			bi->bi_len = bytes;
+		/* header block */
+		} else if (x == 0) {
+			bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_rgrp);
+			bi->bi_offset = sizeof(struct gfs2_rgrp);
+			bi->bi_start = 0;
+			bi->bi_len = bytes;
+		/* last block */
+		} else if (x + 1 == length) {
+			bytes = bytes_left;
+			bi->bi_offset = sizeof(struct gfs2_meta_header);
+			bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
+			bi->bi_len = bytes;
+		/* other blocks */
+		} else {
+			bytes = sdp->sd_sb.sb_bsize -
+				sizeof(struct gfs2_meta_header);
+			bi->bi_offset = sizeof(struct gfs2_meta_header);
+			bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left;
+			bi->bi_len = bytes;
+		}
+
+		bytes_left -= bytes;
+	}
+
+	if (bytes_left) {
+		gfs2_consist_rgrpd(rgd);
+		return -EIO;
+	}
+	bi = rgd->rd_bits + (length - 1);
+	if ((bi->bi_start + bi->bi_len) * GFS2_NBBY != rgd->rd_ri.ri_data) {
+		if (gfs2_consist_rgrpd(rgd)) {
+			gfs2_rindex_print(&rgd->rd_ri);
+			fs_err(sdp, "start=%u len=%u offset=%u\n",
+			       bi->bi_start, bi->bi_len, bi->bi_offset);
+		}
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_ri_update - Pull in a new resource index from the disk
+ * @gl: The glock covering the rindex inode
+ *
+ * Returns: 0 on successful update, error code otherwise
+ */
+
+static int gfs2_ri_update(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct inode *inode = &ip->i_inode;
+	struct gfs2_rgrpd *rgd;
+	char buf[sizeof(struct gfs2_rindex)];
+	struct file_ra_state ra_state;
+	uint64_t junk = ip->i_di.di_size;
+	int error;
+
+	if (do_div(junk, sizeof(struct gfs2_rindex))) {
+		gfs2_consist_inode(ip);
+		return -EIO;
+	}
+
+	clear_rgrpdi(sdp);
+
+	file_ra_state_init(&ra_state, inode->i_mapping);
+	for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
+		loff_t pos = sdp->sd_rgrps * sizeof(struct gfs2_rindex);
+		error = gfs2_internal_read(ip, &ra_state, buf, &pos,
+					    sizeof(struct gfs2_rindex));
+		if (!error)
+			break;
+		if (error != sizeof(struct gfs2_rindex)) {
+			if (error > 0)
+				error = -EIO;
+			goto fail;
+		}
+
+		rgd = kzalloc(sizeof(struct gfs2_rgrpd), GFP_NOFS);
+		error = -ENOMEM;
+		if (!rgd)
+			goto fail;
+
+		mutex_init(&rgd->rd_mutex);
+		lops_init_le(&rgd->rd_le, &gfs2_rg_lops);
+		rgd->rd_sbd = sdp;
+
+		list_add_tail(&rgd->rd_list, &sdp->sd_rindex_list);
+		list_add_tail(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
+
+		gfs2_rindex_in(&rgd->rd_ri, buf);
+		error = compute_bitstructs(rgd);
+		if (error)
+			goto fail;
+
+		error = gfs2_glock_get(sdp, rgd->rd_ri.ri_addr,
+				       &gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
+		if (error)
+			goto fail;
+
+		rgd->rd_gl->gl_object = rgd;
+		rgd->rd_rg_vn = rgd->rd_gl->gl_vn - 1;
+	}
+
+	sdp->sd_rindex_vn = ip->i_gl->gl_vn;
+	return 0;
+
+fail:
+	clear_rgrpdi(sdp);
+	return error;
+}
+
+/**
+ * gfs2_rindex_hold - Grab a lock on the rindex
+ * @sdp: The GFS2 superblock
+ * @ri_gh: the glock holder
+ *
+ * We grab a lock on the rindex inode to make sure that it doesn't
+ * change whilst we are performing an operation. We keep this lock
+ * for quite long periods of time compared to other locks. This
+ * doesn't matter, since it is shared and it is very, very rarely
+ * accessed in the exclusive mode (i.e. only when expanding the filesystem).
+ *
+ * This makes sure that we're using the latest copy of the resource index
+ * special file, which might have been updated if someone expanded the
+ * filesystem (via gfs2_grow utility), which adds new resource groups.
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
+	struct gfs2_glock *gl = ip->i_gl;
+	int error;
+
+	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, ri_gh);
+	if (error)
+		return error;
+
+	/* Read new copy from disk if we don't have the latest */
+	if (sdp->sd_rindex_vn != gl->gl_vn) {
+		mutex_lock(&sdp->sd_rindex_mutex);
+		if (sdp->sd_rindex_vn != gl->gl_vn) {
+			error = gfs2_ri_update(ip);
+			if (error)
+				gfs2_glock_dq_uninit(ri_gh);
+		}
+		mutex_unlock(&sdp->sd_rindex_mutex);
+	}
+
+	return error;
+}
+
+/**
+ * gfs2_rgrp_bh_get - Read in a RG's header and bitmaps
+ * @rgd: the struct gfs2_rgrpd describing the RG to read in
+ *
+ * Read in all of a Resource Group's header and bitmap blocks.
+ * Caller must eventually call gfs2_rgrp_relse() to free the bitmaps.
+ *
+ * Returns: errno
+ */
+
+int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_glock *gl = rgd->rd_gl;
+	unsigned int length = rgd->rd_ri.ri_length;
+	struct gfs2_bitmap *bi;
+	unsigned int x, y;
+	int error;
+
+	mutex_lock(&rgd->rd_mutex);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	if (rgd->rd_bh_count) {
+		rgd->rd_bh_count++;
+		spin_unlock(&sdp->sd_rindex_spin);
+		mutex_unlock(&rgd->rd_mutex);
+		return 0;
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+		error = gfs2_meta_read(gl, rgd->rd_ri.ri_addr + x, DIO_START,
+				       &bi->bi_bh);
+		if (error)
+			goto fail;
+	}
+
+	for (y = length; y--;) {
+		bi = rgd->rd_bits + y;
+		error = gfs2_meta_reread(sdp, bi->bi_bh, DIO_WAIT);
+		if (error)
+			goto fail;
+		if (gfs2_metatype_check(sdp, bi->bi_bh, y ? GFS2_METATYPE_RB :
+					      GFS2_METATYPE_RG)) {
+			error = -EIO;
+			goto fail;
+		}
+	}
+
+	if (rgd->rd_rg_vn != gl->gl_vn) {
+		gfs2_rgrp_in(&rgd->rd_rg, (rgd->rd_bits[0].bi_bh)->b_data);
+		rgd->rd_rg_vn = gl->gl_vn;
+	}
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone = rgd->rd_rg.rg_free;
+	rgd->rd_bh_count++;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	mutex_unlock(&rgd->rd_mutex);
+
+	return 0;
+
+fail:
+	while (x--) {
+		bi = rgd->rd_bits + x;
+		brelse(bi->bi_bh);
+		bi->bi_bh = NULL;
+		gfs2_assert_warn(sdp, !bi->bi_clone);
+	}
+	mutex_unlock(&rgd->rd_mutex);
+
+	return error;
+}
+
+void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
+	rgd->rd_bh_count++;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * gfs2_rgrp_bh_put - Release RG bitmaps read in with gfs2_rgrp_bh_get()
+ * @rgd: the struct gfs2_rgrpd describing the RG to read in
+ *
+ */
+
+void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	int x, length = rgd->rd_ri.ri_length;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
+	if (--rgd->rd_bh_count) {
+		spin_unlock(&sdp->sd_rindex_spin);
+		return;
+	}
+
+	for (x = 0; x < length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		kfree(bi->bi_clone);
+		bi->bi_clone = NULL;
+		brelse(bi->bi_bh);
+		bi->bi_bh = NULL;
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	unsigned int length = rgd->rd_ri.ri_length;
+	unsigned int x;
+
+	for (x = 0; x < length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		if (!bi->bi_clone)
+			continue;
+		memcpy(bi->bi_clone + bi->bi_offset,
+		       bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
+	}
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone = rgd->rd_rg.rg_free;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * gfs2_alloc_get - get the struct gfs2_alloc structure for an inode
+ * @ip: the incore GFS2 inode structure
+ *
+ * Returns: the struct gfs2_alloc
+ */
+
+struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip)
+{
+	struct gfs2_alloc *al = &ip->i_alloc;
+
+	/* FIXME: Should assert that the correct locks are held here... */
+	memset(al, 0, sizeof(*al));
+	return al;
+}
+
+/**
+ * gfs2_alloc_put - throw away the struct gfs2_alloc for an inode
+ * @ip: the inode
+ *
+ */
+
+void gfs2_alloc_put(struct gfs2_inode *ip)
+{
+	return;
+}
+
+/**
+ * try_rgrp_fit - See if a given reservation will fit in a given RG
+ * @rgd: the RG data
+ * @al: the struct gfs2_alloc structure describing the reservation
+ *
+ * If there's room for the requested blocks to be allocated from the RG:
+ *   Sets the $al_reserved_data field in @al.
+ *   Sets the $al_reserved_meta field in @al.
+ *   Sets the $al_rgd field in @al.
+ *
+ * Returns: 1 on success (it fits), 0 on failure (it doesn't fit)
+ */
+
+static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	int ret = 0;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	if (rgd->rd_free_clone >= al->al_requested) {
+		al->al_rgd = rgd;
+		ret = 1;
+	}
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return ret;
+}
+
+/**
+ * recent_rgrp_first - get first RG from "recent" list
+ * @sdp: The GFS2 superblock
+ * @rglast: address of the rgrp used last
+ *
+ * Returns: The first rgrp in the recent list
+ */
+
+static struct gfs2_rgrpd *recent_rgrp_first(struct gfs2_sbd *sdp,
+					    uint64_t rglast)
+{
+	struct gfs2_rgrpd *rgd = NULL;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	if (list_empty(&sdp->sd_rindex_recent_list))
+		goto out;
+
+	if (!rglast)
+		goto first;
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
+		if (rgd->rd_ri.ri_addr == rglast)
+			goto out;
+	}
+
+first:
+	rgd = list_entry(sdp->sd_rindex_recent_list.next, struct gfs2_rgrpd,
+			 rd_recent);
+out:
+	spin_unlock(&sdp->sd_rindex_spin);
+	return rgd;
+}
+
+/**
+ * recent_rgrp_next - get next RG from "recent" list
+ * @cur_rgd: current rgrp
+ * @remove:
+ *
+ * Returns: The next rgrp in the recent list
+ */
+
+static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd,
+					   int remove)
+{
+	struct gfs2_sbd *sdp = cur_rgd->rd_sbd;
+	struct list_head *head;
+	struct gfs2_rgrpd *rgd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	head = &sdp->sd_rindex_recent_list;
+
+	list_for_each_entry(rgd, head, rd_recent) {
+		if (rgd == cur_rgd) {
+			if (cur_rgd->rd_recent.next != head)
+				rgd = list_entry(cur_rgd->rd_recent.next,
+						 struct gfs2_rgrpd, rd_recent);
+			else
+				rgd = NULL;
+
+			if (remove)
+				list_del(&cur_rgd->rd_recent);
+
+			goto out;
+		}
+	}
+
+	rgd = NULL;
+	if (!list_empty(head))
+		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
+
+out:
+	spin_unlock(&sdp->sd_rindex_spin);
+	return rgd;
+}
+
+/**
+ * recent_rgrp_add - add an RG to tail of "recent" list
+ * @new_rgd: The rgrp to add
+ *
+ */
+
+static void recent_rgrp_add(struct gfs2_rgrpd *new_rgd)
+{
+	struct gfs2_sbd *sdp = new_rgd->rd_sbd;
+	struct gfs2_rgrpd *rgd;
+	unsigned int count = 0;
+	unsigned int max = sdp->sd_rgrps / gfs2_jindex_size(sdp);
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) {
+		if (rgd == new_rgd)
+			goto out;
+
+		if (++count >= max)
+			goto out;
+	}
+	list_add_tail(&new_rgd->rd_recent, &sdp->sd_rindex_recent_list);
+
+out:
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * forward_rgrp_get - get an rgrp to try next from full list
+ * @sdp: The GFS2 superblock
+ *
+ * Returns: The rgrp to try next
+ */
+
+static struct gfs2_rgrpd *forward_rgrp_get(struct gfs2_sbd *sdp)
+{
+	struct gfs2_rgrpd *rgd;
+	unsigned int journals = gfs2_jindex_size(sdp);
+	unsigned int rg = 0, x;
+
+	spin_lock(&sdp->sd_rindex_spin);
+
+	rgd = sdp->sd_rindex_forward;
+	if (!rgd) {
+		if (sdp->sd_rgrps >= journals)
+			rg = sdp->sd_rgrps * sdp->sd_jdesc->jd_jid / journals;
+
+		for (x = 0, rgd = gfs2_rgrpd_get_first(sdp); x < rg;
+		     x++, rgd = gfs2_rgrpd_get_next(rgd))
+			/* Do Nothing */;
+
+		sdp->sd_rindex_forward = rgd;
+	}
+
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return rgd;
+}
+
+/**
+ * forward_rgrp_set - set the forward rgrp pointer
+ * @sdp: the filesystem
+ * @rgd: The new forward rgrp
+ *
+ */
+
+static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd)
+{
+	spin_lock(&sdp->sd_rindex_spin);
+	sdp->sd_rindex_forward = rgd;
+	spin_unlock(&sdp->sd_rindex_spin);
+}
+
+/**
+ * get_local_rgrp - Choose and lock a rgrp for allocation
+ * @ip: the inode to reserve space for
+ * @rgp: the chosen and locked rgrp
+ *
+ * Try to acquire rgrp in way which avoids contending with others.
+ *
+ * Returns: errno
+ */
+
+static int get_local_rgrp(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_rgrpd *rgd, *begin = NULL;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	int flags = LM_FLAG_TRY;
+	int skipped = 0;
+	int loops = 0;
+	int error;
+
+	/* Try recently successful rgrps */
+
+	rgd = recent_rgrp_first(sdp, ip->i_last_rg_alloc);
+
+	while (rgd) {
+		error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 
+					   LM_FLAG_TRY, &al->al_rgd_gh);
+		switch (error) {
+		case 0:
+			if (try_rgrp_fit(rgd, al))
+				goto out;
+			gfs2_glock_dq_uninit(&al->al_rgd_gh);
+			rgd = recent_rgrp_next(rgd, 1);
+			break;
+
+		case GLR_TRYFAILED:
+			rgd = recent_rgrp_next(rgd, 0);
+			break;
+
+		default:
+			return error;
+		}
+	}
+
+	/* Go through full list of rgrps */
+
+	begin = rgd = forward_rgrp_get(sdp);
+
+	for (;;) {
+		error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, flags,
+					  &al->al_rgd_gh);
+		switch (error) {
+		case 0:
+			if (try_rgrp_fit(rgd, al))
+				goto out;
+			gfs2_glock_dq_uninit(&al->al_rgd_gh);
+			break;
+
+		case GLR_TRYFAILED:
+			skipped++;
+			break;
+
+		default:
+			return error;
+		}
+
+		rgd = gfs2_rgrpd_get_next(rgd);
+		if (!rgd)
+			rgd = gfs2_rgrpd_get_first(sdp);
+
+		if (rgd == begin) {
+			if (++loops >= 2 || !skipped)
+				return -ENOSPC;
+			flags = 0;
+		}
+	}
+
+out:
+	ip->i_last_rg_alloc = rgd->rd_ri.ri_addr;
+
+	if (begin) {
+		recent_rgrp_add(rgd);
+		rgd = gfs2_rgrpd_get_next(rgd);
+		if (!rgd)
+			rgd = gfs2_rgrpd_get_first(sdp);
+		forward_rgrp_set(sdp, rgd);
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_inplace_reserve_i - Reserve space in the filesystem
+ * @ip: the inode to reserve space for
+ *
+ * Returns: errno
+ */
+
+int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_alloc *al = &ip->i_alloc;
+	int error;
+
+	if (gfs2_assert_warn(sdp, al->al_requested))
+		return -EINVAL;
+
+	error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
+	if (error)
+		return error;
+
+	error = get_local_rgrp(ip);
+	if (error) {
+		gfs2_glock_dq_uninit(&al->al_ri_gh);
+		return error;
+	}
+
+	al->al_file = file;
+	al->al_line = line;
+
+	return 0;
+}
+
+/**
+ * gfs2_inplace_release - release an inplace reservation
+ * @ip: the inode the reservation was taken out on
+ *
+ * Release a reservation made by gfs2_inplace_reserve().
+ */
+
+void gfs2_inplace_release(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_alloc *al = &ip->i_alloc;
+
+	if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1)
+		fs_warn(sdp, "al_alloced = %u, al_requested = %u "
+			     "al_file = %s, al_line = %u\n",
+		             al->al_alloced, al->al_requested, al->al_file,
+			     al->al_line);
+
+	al->al_rgd = NULL;
+	gfs2_glock_dq_uninit(&al->al_rgd_gh);
+	gfs2_glock_dq_uninit(&al->al_ri_gh);
+}
+
+/**
+ * gfs2_get_block_type - Check a block in a RG is of given type
+ * @rgd: the resource group holding the block
+ * @block: the block number
+ *
+ * Returns: The block type (GFS2_BLKST_*)
+ */
+
+unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block)
+{
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length, rgrp_block, buf_block;
+	unsigned int buf;
+	unsigned char type;
+
+	length = rgd->rd_ri.ri_length;
+	rgrp_block = block - rgd->rd_ri.ri_data0;
+
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		if (rgrp_block < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+			break;
+	}
+
+	gfs2_assert(rgd->rd_sbd, buf < length);
+	buf_block = rgrp_block - bi->bi_start * GFS2_NBBY;
+
+	type = gfs2_testbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
+			   bi->bi_len, buf_block);
+
+	return type;
+}
+
+/**
+ * rgblk_search - find a block in @old_state, change allocation
+ *           state to @new_state
+ * @rgd: the resource group descriptor
+ * @goal: the goal block within the RG (start here to search for avail block)
+ * @old_state: GFS2_BLKST_XXX the before-allocation state to find
+ * @new_state: GFS2_BLKST_XXX the after-allocation block state
+ *
+ * Walk rgrp's bitmap to find bits that represent a block in @old_state.
+ * Add the found bitmap buffer to the transaction.
+ * Set the found bits to @new_state to change block's allocation state.
+ *
+ * This function never fails, because we wouldn't call it unless we
+ * know (from reservation results, etc.) that a block is available.
+ *
+ * Scope of @goal and returned block is just within rgrp, not the whole
+ * filesystem.
+ *
+ * Returns:  the block number allocated
+ */
+
+static uint32_t rgblk_search(struct gfs2_rgrpd *rgd, uint32_t goal,
+			     unsigned char old_state, unsigned char new_state)
+{
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length = rgd->rd_ri.ri_length;
+	uint32_t blk = 0;
+	unsigned int buf, x;
+
+	/* Find bitmap block that contains bits for goal block */
+	for (buf = 0; buf < length; buf++) {
+		bi = rgd->rd_bits + buf;
+		if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+			break;
+	}
+
+	gfs2_assert(rgd->rd_sbd, buf < length);
+
+	/* Convert scope of "goal" from rgrp-wide to within found bit block */
+	goal -= bi->bi_start * GFS2_NBBY;
+
+	/* Search (up to entire) bitmap in this rgrp for allocatable block.
+	   "x <= length", instead of "x < length", because we typically start
+	   the search in the middle of a bit block, but if we can't find an
+	   allocatable block anywhere else, we want to be able wrap around and
+	   search in the first part of our first-searched bit block.  */
+	for (x = 0; x <= length; x++) {
+		if (bi->bi_clone)
+			blk = gfs2_bitfit(rgd, bi->bi_clone + bi->bi_offset,
+					  bi->bi_len, goal, old_state);
+		else
+			blk = gfs2_bitfit(rgd,
+					  bi->bi_bh->b_data + bi->bi_offset,
+					  bi->bi_len, goal, old_state);
+		if (blk != BFITNOENT)
+			break;
+
+		/* Try next bitmap block (wrap back to rgrp header if at end) */
+		buf = (buf + 1) % length;
+		bi = rgd->rd_bits + buf;
+		goal = 0;
+	}
+
+	if (gfs2_assert_withdraw(rgd->rd_sbd, x <= length))
+		blk = 0;
+
+	gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
+	gfs2_setbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
+		    bi->bi_len, blk, new_state);
+	if (bi->bi_clone)
+		gfs2_setbit(rgd, bi->bi_clone + bi->bi_offset,
+			    bi->bi_len, blk, new_state);
+
+	return bi->bi_start * GFS2_NBBY + blk;
+}
+
+/**
+ * rgblk_free - Change alloc state of given block(s)
+ * @sdp: the filesystem
+ * @bstart: the start of a run of blocks to free
+ * @blen: the length of the block run (all must lie within ONE RG!)
+ * @new_state: GFS2_BLKST_XXX the after-allocation block state
+ *
+ * Returns:  Resource group containing the block(s)
+ */
+
+static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, uint64_t bstart,
+				     uint32_t blen, unsigned char new_state)
+{
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_bitmap *bi = NULL;
+	uint32_t length, rgrp_blk, buf_blk;
+	unsigned int buf;
+
+	rgd = gfs2_blk2rgrpd(sdp, bstart);
+	if (!rgd) {
+		if (gfs2_consist(sdp))
+			fs_err(sdp, "block = %llu\n", (unsigned long long)bstart);
+		return NULL;
+	}
+
+	length = rgd->rd_ri.ri_length;
+
+	rgrp_blk = bstart - rgd->rd_ri.ri_data0;
+
+	while (blen--) {
+		for (buf = 0; buf < length; buf++) {
+			bi = rgd->rd_bits + buf;
+			if (rgrp_blk < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
+				break;
+		}
+
+		gfs2_assert(rgd->rd_sbd, buf < length);
+
+		buf_blk = rgrp_blk - bi->bi_start * GFS2_NBBY;
+		rgrp_blk++;
+
+		if (!bi->bi_clone) {
+			bi->bi_clone = kmalloc(bi->bi_bh->b_size,
+					       GFP_NOFS | __GFP_NOFAIL);
+			memcpy(bi->bi_clone + bi->bi_offset,
+			       bi->bi_bh->b_data + bi->bi_offset,
+			       bi->bi_len);
+		}
+		gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
+		gfs2_setbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
+			    bi->bi_len, buf_blk, new_state);
+	}
+
+	return rgd;
+}
+
+/**
+ * gfs2_alloc_data - Allocate a data block
+ * @ip: the inode to allocate the data block for
+ *
+ * Returns: the allocated block
+ */
+
+u64 gfs2_alloc_data(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	uint32_t goal, blk;
+	uint64_t block;
+
+	if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_data))
+		goal = ip->i_di.di_goal_data - rgd->rd_ri.ri_data0;
+	else
+		goal = rgd->rd_last_alloc_data;
+
+	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	rgd->rd_last_alloc_data = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+	ip->i_di.di_goal_data = block;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, 0);
+	gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_alloc_meta - Allocate a metadata block
+ * @ip: the inode to allocate the metadata block for
+ *
+ * Returns: the allocated block
+ */
+
+u64 gfs2_alloc_meta(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	uint32_t goal, blk;
+	uint64_t block;
+
+	if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_meta))
+		goal = ip->i_di.di_goal_meta - rgd->rd_ri.ri_data0;
+	else
+		goal = rgd->rd_last_alloc_meta;
+
+	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
+	rgd->rd_last_alloc_meta = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+	ip->i_di.di_goal_meta = block;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, 0);
+	gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_trans_add_unrevoke(sdp, block);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_alloc_di - Allocate a dinode
+ * @dip: the directory that the inode is going in
+ *
+ * Returns: the block allocated
+ */
+
+u64 gfs2_alloc_di(struct gfs2_inode *dip, u64 *generation)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
+	struct gfs2_alloc *al = &dip->i_alloc;
+	struct gfs2_rgrpd *rgd = al->al_rgd;
+	u32 blk;
+	u64 block;
+
+	blk = rgblk_search(rgd, rgd->rd_last_alloc_meta,
+			   GFS2_BLKST_FREE, GFS2_BLKST_DINODE);
+
+	rgd->rd_last_alloc_meta = blk;
+
+	block = rgd->rd_ri.ri_data0 + blk;
+
+	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
+	rgd->rd_rg.rg_free--;
+	rgd->rd_rg.rg_dinodes++;
+	*generation = rgd->rd_rg.rg_igeneration++;
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	al->al_alloced++;
+
+	gfs2_statfs_change(sdp, 0, -1, +1);
+	gfs2_trans_add_unrevoke(sdp, block);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	rgd->rd_free_clone--;
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return block;
+}
+
+/**
+ * gfs2_free_data - free a contiguous run of data block(s)
+ * @ip: the inode these blocks are being freed from
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ *
+ */
+
+void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_rgrpd *rgd;
+
+	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
+	if (!rgd)
+		return;
+
+	rgd->rd_rg.rg_free += blen;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_trans_add_rg(rgd);
+
+	gfs2_statfs_change(sdp, 0, +blen, 0);
+	gfs2_quota_change(ip, -(int64_t)blen,
+			 ip->i_di.di_uid, ip->i_di.di_gid);
+}
+
+/**
+ * gfs2_free_meta - free a contiguous run of data block(s)
+ * @ip: the inode these blocks are being freed from
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ *
+ */
+
+void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_rgrpd *rgd;
+
+	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
+	if (!rgd)
+		return;
+
+	rgd->rd_rg.rg_free += blen;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_trans_add_rg(rgd);
+
+	gfs2_statfs_change(sdp, 0, +blen, 0);
+	gfs2_quota_change(ip, -(int64_t)blen, ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_meta_wipe(ip, bstart, blen);
+}
+
+void gfs2_unlink_di(struct inode *inode)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct gfs2_rgrpd *rgd;
+	u64 blkno = ip->i_num.no_addr;
+
+	rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_UNLINKED);
+	if (!rgd)
+		return;
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+	gfs2_trans_add_rg(rgd);
+}
+
+static void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_rgrpd *tmp_rgd;
+
+	tmp_rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_FREE);
+	if (!tmp_rgd)
+		return;
+	gfs2_assert_withdraw(sdp, rgd == tmp_rgd);
+
+	if (!rgd->rd_rg.rg_dinodes)
+		gfs2_consist_rgrpd(rgd);
+	rgd->rd_rg.rg_dinodes--;
+	rgd->rd_rg.rg_free++;
+
+	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_statfs_change(sdp, 0, +1, -1);
+	gfs2_trans_add_rg(rgd);
+}
+
+
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
+{
+	gfs2_free_uninit_di(rgd, ip->i_num.no_addr);
+	gfs2_quota_change(ip, -1, ip->i_di.di_uid, ip->i_di.di_gid);
+	gfs2_meta_wipe(ip, ip->i_num.no_addr, 1);
+}
+
+/**
+ * gfs2_rlist_add - add a RG to a list of RGs
+ * @sdp: the filesystem
+ * @rlist: the list of resource groups
+ * @block: the block
+ *
+ * Figure out what RG a block belongs to and add that RG to the list
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
+		    uint64_t block)
+{
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_rgrpd **tmp;
+	unsigned int new_space;
+	unsigned int x;
+
+	if (gfs2_assert_warn(sdp, !rlist->rl_ghs))
+		return;
+
+	rgd = gfs2_blk2rgrpd(sdp, block);
+	if (!rgd) {
+		if (gfs2_consist(sdp))
+			fs_err(sdp, "block = %llu\n", (unsigned long long)block);
+		return;
+	}
+
+	for (x = 0; x < rlist->rl_rgrps; x++)
+		if (rlist->rl_rgd[x] == rgd)
+			return;
+
+	if (rlist->rl_rgrps == rlist->rl_space) {
+		new_space = rlist->rl_space + 10;
+
+		tmp = kcalloc(new_space, sizeof(struct gfs2_rgrpd *),
+			      GFP_NOFS | __GFP_NOFAIL);
+
+		if (rlist->rl_rgd) {
+			memcpy(tmp, rlist->rl_rgd,
+			       rlist->rl_space * sizeof(struct gfs2_rgrpd *));
+			kfree(rlist->rl_rgd);
+		}
+
+		rlist->rl_space = new_space;
+		rlist->rl_rgd = tmp;
+	}
+
+	rlist->rl_rgd[rlist->rl_rgrps++] = rgd;
+}
+
+/**
+ * gfs2_rlist_alloc - all RGs have been added to the rlist, now allocate
+ *      and initialize an array of glock holders for them
+ * @rlist: the list of resource groups
+ * @state: the lock state to acquire the RG lock in
+ * @flags: the modifier flags for the holder structures
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
+		      int flags)
+{
+	unsigned int x;
+
+	rlist->rl_ghs = kcalloc(rlist->rl_rgrps, sizeof(struct gfs2_holder),
+				GFP_NOFS | __GFP_NOFAIL);
+	for (x = 0; x < rlist->rl_rgrps; x++)
+		gfs2_holder_init(rlist->rl_rgd[x]->rd_gl,
+				state, flags,
+				&rlist->rl_ghs[x]);
+}
+
+/**
+ * gfs2_rlist_free - free a resource group list
+ * @list: the list of resource groups
+ *
+ */
+
+void gfs2_rlist_free(struct gfs2_rgrp_list *rlist)
+{
+	unsigned int x;
+
+	kfree(rlist->rl_rgd);
+
+	if (rlist->rl_ghs) {
+		for (x = 0; x < rlist->rl_rgrps; x++)
+			gfs2_holder_uninit(&rlist->rl_ghs[x]);
+		kfree(rlist->rl_ghs);
+	}
+}
+
--- /dev/null
+++ b/fs/gfs2/rgrp.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#ifndef __RGRP_DOT_H__
+#define __RGRP_DOT_H__
+
+void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd);
+
+struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk);
+struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp);
+struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd);
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp);
+int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh);
+
+int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd);
+void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd);
+void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd);
+
+void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd);
+
+struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip);
+void gfs2_alloc_put(struct gfs2_inode *ip);
+
+int gfs2_inplace_reserve_i(struct gfs2_inode *ip,
+			 char *file, unsigned int line);
+#define gfs2_inplace_reserve(ip) \
+gfs2_inplace_reserve_i((ip), __FILE__, __LINE__)
+
+void gfs2_inplace_release(struct gfs2_inode *ip);
+
+unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block);
+
+u64 gfs2_alloc_data(struct gfs2_inode *ip);
+u64 gfs2_alloc_meta(struct gfs2_inode *ip);
+u64 gfs2_alloc_di(struct gfs2_inode *ip, u64 *generation);
+
+void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen);
+void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen);
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip);
+void gfs2_unlink_di(struct inode *inode);
+
+struct gfs2_rgrp_list {
+	unsigned int rl_rgrps;
+	unsigned int rl_space;
+	struct gfs2_rgrpd **rl_rgd;
+	struct gfs2_holder *rl_ghs;
+};
+
+void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
+		    uint64_t block);
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
+		      int flags);
+void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
+
+#endif /* __RGRP_DOT_H__ */