[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

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

1 files changed, 1361 insertions, 0 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
new file mode 100644
index 0000000..8df6fba
--- /dev/null
+++ b/fs/gfs2/rgrp.c
@@ -0,0 +1,1361 @@
+/*
+ * 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 <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bits.h"
+#include "glock.h"
+#include "glops.h"
+#include "jdata.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "super.h"
+#include "trans.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) {
+			set_gl2rgd(gl, NULL);
+			gfs2_glock_put(gl);
+		}
+
+		kfree(rgd->rd_bits);
+		kfree(rgd);
+	}
+}
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
+{
+	down(&sdp->sd_rindex_mutex);
+	clear_rgrpdi(sdp);
+	up(&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 gfs2_rgrpd *rgd;
+	char buf[sizeof(struct gfs2_rindex)];
+	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);
+
+	for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
+		error = gfs2_jdata_read_mem(ip, buf,
+					    sdp->sd_rgrps *
+					    sizeof(struct gfs2_rindex),
+					    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;
+
+		init_MUTEX(&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;
+
+		set_gl2rgd(rgd->rd_gl, 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;
+	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) {
+		down(&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);
+		}
+		up(&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;
+
+	down(&rgd->rd_mutex);
+
+	spin_lock(&sdp->sd_rindex_spin);
+	if (rgd->rd_bh_count) {
+		rgd->rd_bh_count++;
+		spin_unlock(&sdp->sd_rindex_spin);
+		up(&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);
+
+	up(&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);
+	}
+	up(&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);
+	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);
+		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);
+	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);
+	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);
+	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);
+	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);
+	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);
+	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);
+	}
+}
+