Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2664 insertions, 0 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
new file mode 100644
index 000000000..1ffdc4ad6
--- /dev/null
+++ b/fs/gfs2/rgrp.c
@@ -0,0 +1,2664 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 <linux/prefetch.h>
+#include <linux/blkdev.h>
+#include <linux/rbtree.h>
+#include <linux/random.h>
+
+#include "gfs2.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 "util.h"
+#include "log.h"
+#include "inode.h"
+#include "trace_gfs2.h"
+#include "dir.h"
+
+#define BFITNOENT ((u32)~0)
+#define NO_BLOCK ((u64)~0)
+
+/*
+ * 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)
+ */
+
+struct gfs2_extent {
+	struct gfs2_rbm rbm;
+	u32 len;
+};
+
+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
+};
+
+static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
+			 const struct gfs2_inode *ip, bool nowrap);
+
+
+/**
+ * gfs2_setbit - Set a bit in the bitmaps
+ * @rbm: The position of the bit to set
+ * @do_clone: Also set the clone bitmap, if it exists
+ * @new_state: the new state of the block
+ *
+ */
+
+static inline void gfs2_setbit(const struct gfs2_rbm *rbm, bool do_clone,
+			       unsigned char new_state)
+{
+	unsigned char *byte1, *byte2, *end, cur_state;
+	struct gfs2_bitmap *bi = rbm_bi(rbm);
+	unsigned int buflen = bi->bi_bytes;
+	const unsigned int bit = (rbm->offset % GFS2_NBBY) * GFS2_BIT_SIZE;
+
+	byte1 = bi->bi_bh->b_data + bi->bi_offset + (rbm->offset / GFS2_NBBY);
+	end = bi->bi_bh->b_data + bi->bi_offset + buflen;
+
+	BUG_ON(byte1 >= end);
+
+	cur_state = (*byte1 >> bit) & GFS2_BIT_MASK;
+
+	if (unlikely(!valid_change[new_state * 4 + cur_state])) {
+		struct gfs2_sbd *sdp = rbm->rgd->rd_sbd;
+
+		fs_warn(sdp, "buf_blk = 0x%x old_state=%d, new_state=%d\n",
+			rbm->offset, cur_state, new_state);
+		fs_warn(sdp, "rgrp=0x%llx bi_start=0x%x biblk: 0x%llx\n",
+			(unsigned long long)rbm->rgd->rd_addr, bi->bi_start,
+			(unsigned long long)bi->bi_bh->b_blocknr);
+		fs_warn(sdp, "bi_offset=0x%x bi_bytes=0x%x block=0x%llx\n",
+			bi->bi_offset, bi->bi_bytes,
+			(unsigned long long)gfs2_rbm_to_block(rbm));
+		dump_stack();
+		gfs2_consist_rgrpd(rbm->rgd);
+		return;
+	}
+	*byte1 ^= (cur_state ^ new_state) << bit;
+
+	if (do_clone && bi->bi_clone) {
+		byte2 = bi->bi_clone + bi->bi_offset + (rbm->offset / GFS2_NBBY);
+		cur_state = (*byte2 >> bit) & GFS2_BIT_MASK;
+		*byte2 ^= (cur_state ^ new_state) << bit;
+	}
+}
+
+/**
+ * gfs2_testbit - test a bit in the bitmaps
+ * @rbm: The bit to test
+ * @use_clone: If true, test the clone bitmap, not the official bitmap.
+ *
+ * Some callers like gfs2_unaligned_extlen need to test the clone bitmaps,
+ * not the "real" bitmaps, to avoid allocating recently freed blocks.
+ *
+ * Returns: The two bit block state of the requested bit
+ */
+
+static inline u8 gfs2_testbit(const struct gfs2_rbm *rbm, bool use_clone)
+{
+	struct gfs2_bitmap *bi = rbm_bi(rbm);
+	const u8 *buffer;
+	const u8 *byte;
+	unsigned int bit;
+
+	if (use_clone && bi->bi_clone)
+		buffer = bi->bi_clone;
+	else
+		buffer = bi->bi_bh->b_data;
+	buffer += bi->bi_offset;
+	byte = buffer + (rbm->offset / GFS2_NBBY);
+	bit = (rbm->offset % GFS2_NBBY) * GFS2_BIT_SIZE;
+
+	return (*byte >> bit) & GFS2_BIT_MASK;
+}
+
+/**
+ * gfs2_bit_search
+ * @ptr: Pointer to bitmap data
+ * @mask: Mask to use (normally 0x55555.... but adjusted for search start)
+ * @state: The state we are searching for
+ *
+ * We xor the bitmap data with a patter which is the bitwise opposite
+ * of what we are looking for, this gives rise to a pattern of ones
+ * wherever there is a match. Since we have two bits per entry, we
+ * take this pattern, shift it down by one place and then and it with
+ * the original. All the even bit positions (0,2,4, etc) then represent
+ * successful matches, so we mask with 0x55555..... to remove the unwanted
+ * odd bit positions.
+ *
+ * This allows searching of a whole u64 at once (32 blocks) with a
+ * single test (on 64 bit arches).
+ */
+
+static inline u64 gfs2_bit_search(const __le64 *ptr, u64 mask, u8 state)
+{
+	u64 tmp;
+	static const u64 search[] = {
+		[0] = 0xffffffffffffffffULL,
+		[1] = 0xaaaaaaaaaaaaaaaaULL,
+		[2] = 0x5555555555555555ULL,
+		[3] = 0x0000000000000000ULL,
+	};
+	tmp = le64_to_cpu(*ptr) ^ search[state];
+	tmp &= (tmp >> 1);
+	tmp &= mask;
+	return tmp;
+}
+
+/**
+ * rs_cmp - multi-block reservation range compare
+ * @blk: absolute file system block number of the new reservation
+ * @len: number of blocks in the new reservation
+ * @rs: existing reservation to compare against
+ *
+ * returns: 1 if the block range is beyond the reach of the reservation
+ *         -1 if the block range is before the start of the reservation
+ *          0 if the block range overlaps with the reservation
+ */
+static inline int rs_cmp(u64 blk, u32 len, struct gfs2_blkreserv *rs)
+{
+	u64 startblk = gfs2_rbm_to_block(&rs->rs_rbm);
+
+	if (blk >= startblk + rs->rs_free)
+		return 1;
+	if (blk + len - 1 < startblk)
+		return -1;
+	return 0;
+}
+
+/**
+ * gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing
+ *       a block in a given allocation state.
+ * @buf: the buffer that holds the bitmaps
+ * @len: the length (in bytes) of the buffer
+ * @goal: start search at this block's bit-pair (within @buffer)
+ * @state: GFS2_BLKST_XXX the state of the block we're looking for.
+ *
+ * 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, but
+ * headers are always a multiple of 64 bits long so that the buffer is
+ * always aligned to a 64 bit boundary.
+ *
+ * The size of the buffer is in bytes, but is it assumed that it is
+ * always ok to read a complete multiple of 64 bits at the end
+ * of the block in case the end is no aligned to a natural boundary.
+ *
+ * Return: the block number (bitmap buffer scope) that was found
+ */
+
+static u32 gfs2_bitfit(const u8 *buf, const unsigned int len,
+		       u32 goal, u8 state)
+{
+	u32 spoint = (goal << 1) & ((8*sizeof(u64)) - 1);
+	const __le64 *ptr = ((__le64 *)buf) + (goal >> 5);
+	const __le64 *end = (__le64 *)(buf + ALIGN(len, sizeof(u64)));
+	u64 tmp;
+	u64 mask = 0x5555555555555555ULL;
+	u32 bit;
+
+	/* Mask off bits we don't care about at the start of the search */
+	mask <<= spoint;
+	tmp = gfs2_bit_search(ptr, mask, state);
+	ptr++;
+	while(tmp == 0 && ptr < end) {
+		tmp = gfs2_bit_search(ptr, 0x5555555555555555ULL, state);
+		ptr++;
+	}
+	/* Mask off any bits which are more than len bytes from the start */
+	if (ptr == end && (len & (sizeof(u64) - 1)))
+		tmp &= (((u64)~0) >> (64 - 8*(len & (sizeof(u64) - 1))));
+	/* Didn't find anything, so return */
+	if (tmp == 0)
+		return BFITNOENT;
+	ptr--;
+	bit = __ffs64(tmp);
+	bit /= 2;	/* two bits per entry in the bitmap */
+	return (((const unsigned char *)ptr - buf) * GFS2_NBBY) + bit;
+}
+
+/**
+ * gfs2_rbm_from_block - Set the rbm based upon rgd and block number
+ * @rbm: The rbm with rgd already set correctly
+ * @block: The block number (filesystem relative)
+ *
+ * This sets the bi and offset members of an rbm based on a
+ * resource group and a filesystem relative block number. The
+ * resource group must be set in the rbm on entry, the bi and
+ * offset members will be set by this function.
+ *
+ * Returns: 0 on success, or an error code
+ */
+
+static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block)
+{
+	if (!rgrp_contains_block(rbm->rgd, block))
+		return -E2BIG;
+	rbm->bii = 0;
+	rbm->offset = block - rbm->rgd->rd_data0;
+	/* Check if the block is within the first block */
+	if (rbm->offset < rbm_bi(rbm)->bi_blocks)
+		return 0;
+
+	/* Adjust for the size diff between gfs2_meta_header and gfs2_rgrp */
+	rbm->offset += (sizeof(struct gfs2_rgrp) -
+			sizeof(struct gfs2_meta_header)) * GFS2_NBBY;
+	rbm->bii = rbm->offset / rbm->rgd->rd_sbd->sd_blocks_per_bitmap;
+	rbm->offset -= rbm->bii * rbm->rgd->rd_sbd->sd_blocks_per_bitmap;
+	return 0;
+}
+
+/**
+ * gfs2_rbm_incr - increment an rbm structure
+ * @rbm: The rbm with rgd already set correctly
+ *
+ * This function takes an existing rbm structure and increments it to the next
+ * viable block offset.
+ *
+ * Returns: If incrementing the offset would cause the rbm to go past the
+ *          end of the rgrp, true is returned, otherwise false.
+ *
+ */
+
+static bool gfs2_rbm_incr(struct gfs2_rbm *rbm)
+{
+	if (rbm->offset + 1 < rbm_bi(rbm)->bi_blocks) { /* in the same bitmap */
+		rbm->offset++;
+		return false;
+	}
+	if (rbm->bii == rbm->rgd->rd_length - 1) /* at the last bitmap */
+		return true;
+
+	rbm->offset = 0;
+	rbm->bii++;
+	return false;
+}
+
+/**
+ * gfs2_unaligned_extlen - Look for free blocks which are not byte aligned
+ * @rbm: Position to search (value/result)
+ * @n_unaligned: Number of unaligned blocks to check
+ * @len: Decremented for each block found (terminate on zero)
+ *
+ * Returns: true if a non-free block is encountered
+ */
+
+static bool gfs2_unaligned_extlen(struct gfs2_rbm *rbm, u32 n_unaligned, u32 *len)
+{
+	u32 n;
+	u8 res;
+
+	for (n = 0; n < n_unaligned; n++) {
+		res = gfs2_testbit(rbm, true);
+		if (res != GFS2_BLKST_FREE)
+			return true;
+		(*len)--;
+		if (*len == 0)
+			return true;
+		if (gfs2_rbm_incr(rbm))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * gfs2_free_extlen - Return extent length of free blocks
+ * @rrbm: Starting position
+ * @len: Max length to check
+ *
+ * Starting at the block specified by the rbm, see how many free blocks
+ * there are, not reading more than len blocks ahead. This can be done
+ * using memchr_inv when the blocks are byte aligned, but has to be done
+ * on a block by block basis in case of unaligned blocks. Also this
+ * function can cope with bitmap boundaries (although it must stop on
+ * a resource group boundary)
+ *
+ * Returns: Number of free blocks in the extent
+ */
+
+static u32 gfs2_free_extlen(const struct gfs2_rbm *rrbm, u32 len)
+{
+	struct gfs2_rbm rbm = *rrbm;
+	u32 n_unaligned = rbm.offset & 3;
+	u32 size = len;
+	u32 bytes;
+	u32 chunk_size;
+	u8 *ptr, *start, *end;
+	u64 block;
+	struct gfs2_bitmap *bi;
+
+	if (n_unaligned &&
+	    gfs2_unaligned_extlen(&rbm, 4 - n_unaligned, &len))
+		goto out;
+
+	n_unaligned = len & 3;
+	/* Start is now byte aligned */
+	while (len > 3) {
+		bi = rbm_bi(&rbm);
+		start = bi->bi_bh->b_data;
+		if (bi->bi_clone)
+			start = bi->bi_clone;
+		start += bi->bi_offset;
+		end = start + bi->bi_bytes;
+		BUG_ON(rbm.offset & 3);
+		start += (rbm.offset / GFS2_NBBY);
+		bytes = min_t(u32, len / GFS2_NBBY, (end - start));
+		ptr = memchr_inv(start, 0, bytes);
+		chunk_size = ((ptr == NULL) ? bytes : (ptr - start));
+		chunk_size *= GFS2_NBBY;
+		BUG_ON(len < chunk_size);
+		len -= chunk_size;
+		block = gfs2_rbm_to_block(&rbm);
+		if (gfs2_rbm_from_block(&rbm, block + chunk_size)) {
+			n_unaligned = 0;
+			break;
+		}
+		if (ptr) {
+			n_unaligned = 3;
+			break;
+		}
+		n_unaligned = len & 3;
+	}
+
+	/* Deal with any bits left over at the end */
+	if (n_unaligned)
+		gfs2_unaligned_extlen(&rbm, n_unaligned, &len);
+out:
+	return size - len;
+}
+
+/**
+ * gfs2_bitcount - count the number of bits in a certain state
+ * @rgd: the resource group descriptor
+ * @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 u32 gfs2_bitcount(struct gfs2_rgrpd *rgd, const u8 *buffer,
+			 unsigned int buflen, u8 state)
+{
+	const u8 *byte = buffer;
+	const u8 *end = buffer + buflen;
+	const u8 state1 = state << 2;
+	const u8 state2 = state << 4;
+	const u8 state3 = state << 6;
+	u32 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
+ * @rgd: the rgrp
+ *
+ */
+
+void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_bitmap *bi = NULL;
+	u32 length = rgd->rd_length;
+	u32 count[4], tmp;
+	int buf, x;
+
+	memset(count, 0, 4 * sizeof(u32));
+
+	/* 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_bytes, x);
+	}
+
+	if (count[0] != rgd->rd_free) {
+		gfs2_lm(sdp, "free data mismatch:  %u != %u\n",
+			count[0], rgd->rd_free);
+		gfs2_consist_rgrpd(rgd);
+		return;
+	}
+
+	tmp = rgd->rd_data - rgd->rd_free - rgd->rd_dinodes;
+	if (count[1] != tmp) {
+		gfs2_lm(sdp, "used data mismatch:  %u != %u\n",
+			count[1], tmp);
+		gfs2_consist_rgrpd(rgd);
+		return;
+	}
+
+	if (count[2] + count[3] != rgd->rd_dinodes) {
+		gfs2_lm(sdp, "used metadata mismatch:  %u != %u\n",
+			count[2] + count[3], rgd->rd_dinodes);
+		gfs2_consist_rgrpd(rgd);
+		return;
+	}
+}
+
+/**
+ * gfs2_blk2rgrpd - Find resource group for a given data/meta block number
+ * @sdp: The GFS2 superblock
+ * @blk: The data block number
+ * @exact: True if this needs to be an exact match
+ *
+ * The @exact argument should be set to true by most callers. The exception
+ * is when we need to match blocks which are not represented by the rgrp
+ * bitmap, but which are part of the rgrp (i.e. padding blocks) which are
+ * there for alignment purposes. Another way of looking at it is that @exact
+ * matches only valid data/metadata blocks, but with @exact false, it will
+ * match any block within the extent of the rgrp.
+ *
+ * Returns: The resource group, or NULL if not found
+ */
+
+struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, u64 blk, bool exact)
+{
+	struct rb_node *n, *next;
+	struct gfs2_rgrpd *cur;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	n = sdp->sd_rindex_tree.rb_node;
+	while (n) {
+		cur = rb_entry(n, struct gfs2_rgrpd, rd_node);
+		next = NULL;
+		if (blk < cur->rd_addr)
+			next = n->rb_left;
+		else if (blk >= cur->rd_data0 + cur->rd_data)
+			next = n->rb_right;
+		if (next == NULL) {
+			spin_unlock(&sdp->sd_rindex_spin);
+			if (exact) {
+				if (blk < cur->rd_addr)
+					return NULL;
+				if (blk >= cur->rd_data0 + cur->rd_data)
+					return NULL;
+			}
+			return cur;
+		}
+		n = next;
+	}
+	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)
+{
+	const struct rb_node *n;
+	struct gfs2_rgrpd *rgd;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	n = rb_first(&sdp->sd_rindex_tree);
+	rgd = rb_entry(n, struct gfs2_rgrpd, rd_node);
+	spin_unlock(&sdp->sd_rindex_spin);
+
+	return rgd;
+}
+
+/**
+ * gfs2_rgrpd_get_next - get the next RG
+ * @rgd: the resource group descriptor
+ *
+ * Returns: The next rgrp
+ */
+
+struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	const struct rb_node *n;
+
+	spin_lock(&sdp->sd_rindex_spin);
+	n = rb_next(&rgd->rd_node);
+	if (n == NULL)
+		n = rb_first(&sdp->sd_rindex_tree);
+
+	if (unlikely(&rgd->rd_node == n)) {
+		spin_unlock(&sdp->sd_rindex_spin);
+		return NULL;
+	}
+	rgd = rb_entry(n, struct gfs2_rgrpd, rd_node);
+	spin_unlock(&sdp->sd_rindex_spin);
+	return rgd;
+}
+
+void check_and_update_goal(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	if (!ip->i_goal || gfs2_blk2rgrpd(sdp, ip->i_goal, 1) == NULL)
+		ip->i_goal = ip->i_no_addr;
+}
+
+void gfs2_free_clones(struct gfs2_rgrpd *rgd)
+{
+	int x;
+
+	for (x = 0; x < rgd->rd_length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		kfree(bi->bi_clone);
+		bi->bi_clone = NULL;
+	}
+}
+
+static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs,
+		    const char *fs_id_buf)
+{
+	struct gfs2_inode *ip = container_of(rs, struct gfs2_inode, i_res);
+
+	gfs2_print_dbg(seq, "%s  B: n:%llu s:%llu b:%u f:%u\n", fs_id_buf,
+		       (unsigned long long)ip->i_no_addr,
+		       (unsigned long long)gfs2_rbm_to_block(&rs->rs_rbm),
+		       rs->rs_rbm.offset, rs->rs_free);
+}
+
+/**
+ * __rs_deltree - remove a multi-block reservation from the rgd tree
+ * @rs: The reservation to remove
+ *
+ */
+static void __rs_deltree(struct gfs2_blkreserv *rs)
+{
+	struct gfs2_rgrpd *rgd;
+
+	if (!gfs2_rs_active(rs))
+		return;
+
+	rgd = rs->rs_rbm.rgd;
+	trace_gfs2_rs(rs, TRACE_RS_TREEDEL);
+	rb_erase(&rs->rs_node, &rgd->rd_rstree);
+	RB_CLEAR_NODE(&rs->rs_node);
+
+	if (rs->rs_free) {
+		u64 last_block = gfs2_rbm_to_block(&rs->rs_rbm) +
+				 rs->rs_free - 1;
+		struct gfs2_rbm last_rbm = { .rgd = rs->rs_rbm.rgd, };
+		struct gfs2_bitmap *start, *last;
+
+		/* return reserved blocks to the rgrp */
+		BUG_ON(rs->rs_rbm.rgd->rd_reserved < rs->rs_free);
+		rs->rs_rbm.rgd->rd_reserved -= rs->rs_free;
+		/* The rgrp extent failure point is likely not to increase;
+		   it will only do so if the freed blocks are somehow
+		   contiguous with a span of free blocks that follows. Still,
+		   it will force the number to be recalculated later. */
+		rgd->rd_extfail_pt += rs->rs_free;
+		rs->rs_free = 0;
+		if (gfs2_rbm_from_block(&last_rbm, last_block))
+			return;
+		start = rbm_bi(&rs->rs_rbm);
+		last = rbm_bi(&last_rbm);
+		do
+			clear_bit(GBF_FULL, &start->bi_flags);
+		while (start++ != last);
+	}
+}
+
+/**
+ * gfs2_rs_deltree - remove a multi-block reservation from the rgd tree
+ * @rs: The reservation to remove
+ *
+ */
+void gfs2_rs_deltree(struct gfs2_blkreserv *rs)
+{
+	struct gfs2_rgrpd *rgd;
+
+	rgd = rs->rs_rbm.rgd;
+	if (rgd) {
+		spin_lock(&rgd->rd_rsspin);
+		__rs_deltree(rs);
+		BUG_ON(rs->rs_free);
+		spin_unlock(&rgd->rd_rsspin);
+	}
+}
+
+/**
+ * gfs2_rs_delete - delete a multi-block reservation
+ * @ip: The inode for this reservation
+ *
+ */
+void gfs2_rs_delete(struct gfs2_inode *ip)
+{
+	struct inode *inode = &ip->i_inode;
+
+	down_write(&ip->i_rw_mutex);
+	if (atomic_read(&inode->i_writecount) <= 1)
+		gfs2_rs_deltree(&ip->i_res);
+	up_write(&ip->i_rw_mutex);
+}
+
+/**
+ * return_all_reservations - return all reserved blocks back to the rgrp.
+ * @rgd: the rgrp that needs its space back
+ *
+ * We previously reserved a bunch of blocks for allocation. Now we need to
+ * give them back. This leave the reservation structures in tact, but removes
+ * all of their corresponding "no-fly zones".
+ */
+static void return_all_reservations(struct gfs2_rgrpd *rgd)
+{
+	struct rb_node *n;
+	struct gfs2_blkreserv *rs;
+
+	spin_lock(&rgd->rd_rsspin);
+	while ((n = rb_first(&rgd->rd_rstree))) {
+		rs = rb_entry(n, struct gfs2_blkreserv, rs_node);
+		__rs_deltree(rs);
+	}
+	spin_unlock(&rgd->rd_rsspin);
+}
+
+void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
+{
+	struct rb_node *n;
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_glock *gl;
+
+	while ((n = rb_first(&sdp->sd_rindex_tree))) {
+		rgd = rb_entry(n, struct gfs2_rgrpd, rd_node);
+		gl = rgd->rd_gl;
+
+		rb_erase(n, &sdp->sd_rindex_tree);
+
+		if (gl) {
+			if (gl->gl_state != LM_ST_UNLOCKED) {
+				gfs2_glock_cb(gl, LM_ST_UNLOCKED);
+				flush_delayed_work(&gl->gl_work);
+			}
+			gfs2_rgrp_brelse(rgd);
+			glock_clear_object(gl, rgd);
+			gfs2_glock_put(gl);
+		}
+
+		gfs2_free_clones(rgd);
+		return_all_reservations(rgd);
+		kfree(rgd->rd_bits);
+		rgd->rd_bits = NULL;
+		kmem_cache_free(gfs2_rgrpd_cachep, rgd);
+	}
+}
+
+/**
+ * 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;
+	u32 length = rgd->rd_length; /* # blocks in hdr & bitmap */
+	u32 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_bitbytes;
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+
+		bi->bi_flags = 0;
+		/* 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_bytes = bytes;
+			bi->bi_blocks = bytes * GFS2_NBBY;
+		/* 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_bytes = bytes;
+			bi->bi_blocks = bytes * GFS2_NBBY;
+		/* last block */
+		} else if (x + 1 == length) {
+			bytes = bytes_left;
+			bi->bi_offset = sizeof(struct gfs2_meta_header);
+			bi->bi_start = rgd->rd_bitbytes - bytes_left;
+			bi->bi_bytes = bytes;
+			bi->bi_blocks = bytes * GFS2_NBBY;
+		/* 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_bitbytes - bytes_left;
+			bi->bi_bytes = bytes;
+			bi->bi_blocks = bytes * GFS2_NBBY;
+		}
+
+		bytes_left -= bytes;
+	}
+
+	if (bytes_left) {
+		gfs2_consist_rgrpd(rgd);
+		return -EIO;
+	}
+	bi = rgd->rd_bits + (length - 1);
+	if ((bi->bi_start + bi->bi_bytes) * GFS2_NBBY != rgd->rd_data) {
+		gfs2_lm(sdp,
+			"ri_addr = %llu\n"
+			"ri_length = %u\n"
+			"ri_data0 = %llu\n"
+			"ri_data = %u\n"
+			"ri_bitbytes = %u\n"
+			"start=%u len=%u offset=%u\n",
+			(unsigned long long)rgd->rd_addr,
+			rgd->rd_length,
+			(unsigned long long)rgd->rd_data0,
+			rgd->rd_data,
+			rgd->rd_bitbytes,
+			bi->bi_start, bi->bi_bytes, bi->bi_offset);
+		gfs2_consist_rgrpd(rgd);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_ri_total - Total up the file system space, according to the rindex.
+ * @sdp: the filesystem
+ *
+ */
+u64 gfs2_ri_total(struct gfs2_sbd *sdp)
+{
+	u64 total_data = 0;	
+	struct inode *inode = sdp->sd_rindex;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	char buf[sizeof(struct gfs2_rindex)];
+	int error, rgrps;
+
+	for (rgrps = 0;; rgrps++) {
+		loff_t pos = rgrps * sizeof(struct gfs2_rindex);
+
+		if (pos + sizeof(struct gfs2_rindex) > i_size_read(inode))
+			break;
+		error = gfs2_internal_read(ip, buf, &pos,
+					   sizeof(struct gfs2_rindex));
+		if (error != sizeof(struct gfs2_rindex))
+			break;
+		total_data += be32_to_cpu(((struct gfs2_rindex *)buf)->ri_data);
+	}
+	return total_data;
+}
+
+static int rgd_insert(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct rb_node **newn = &sdp->sd_rindex_tree.rb_node, *parent = NULL;
+
+	/* Figure out where to put new node */
+	while (*newn) {
+		struct gfs2_rgrpd *cur = rb_entry(*newn, struct gfs2_rgrpd,
+						  rd_node);
+
+		parent = *newn;
+		if (rgd->rd_addr < cur->rd_addr)
+			newn = &((*newn)->rb_left);
+		else if (rgd->rd_addr > cur->rd_addr)
+			newn = &((*newn)->rb_right);
+		else
+			return -EEXIST;
+	}
+
+	rb_link_node(&rgd->rd_node, parent, newn);
+	rb_insert_color(&rgd->rd_node, &sdp->sd_rindex_tree);
+	sdp->sd_rgrps++;
+	return 0;
+}
+
+/**
+ * read_rindex_entry - Pull in a new resource index entry from the disk
+ * @ip: Pointer to the rindex inode
+ *
+ * Returns: 0 on success, > 0 on EOF, error code otherwise
+ */
+
+static int read_rindex_entry(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	loff_t pos = sdp->sd_rgrps * sizeof(struct gfs2_rindex);
+	struct gfs2_rindex buf;
+	int error;
+	struct gfs2_rgrpd *rgd;
+
+	if (pos >= i_size_read(&ip->i_inode))
+		return 1;
+
+	error = gfs2_internal_read(ip, (char *)&buf, &pos,
+				   sizeof(struct gfs2_rindex));
+
+	if (error != sizeof(struct gfs2_rindex))
+		return (error == 0) ? 1 : error;
+
+	rgd = kmem_cache_zalloc(gfs2_rgrpd_cachep, GFP_NOFS);
+	error = -ENOMEM;
+	if (!rgd)
+		return error;
+
+	rgd->rd_sbd = sdp;
+	rgd->rd_addr = be64_to_cpu(buf.ri_addr);
+	rgd->rd_length = be32_to_cpu(buf.ri_length);
+	rgd->rd_data0 = be64_to_cpu(buf.ri_data0);
+	rgd->rd_data = be32_to_cpu(buf.ri_data);
+	rgd->rd_bitbytes = be32_to_cpu(buf.ri_bitbytes);
+	spin_lock_init(&rgd->rd_rsspin);
+
+	error = gfs2_glock_get(sdp, rgd->rd_addr,
+			       &gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
+	if (error)
+		goto fail;
+
+	error = compute_bitstructs(rgd);
+	if (error)
+		goto fail_glock;
+
+	rgd->rd_rgl = (struct gfs2_rgrp_lvb *)rgd->rd_gl->gl_lksb.sb_lvbptr;
+	rgd->rd_flags &= ~(GFS2_RDF_UPTODATE | GFS2_RDF_PREFERRED);
+	if (rgd->rd_data > sdp->sd_max_rg_data)
+		sdp->sd_max_rg_data = rgd->rd_data;
+	spin_lock(&sdp->sd_rindex_spin);
+	error = rgd_insert(rgd);
+	spin_unlock(&sdp->sd_rindex_spin);
+	if (!error) {
+		glock_set_object(rgd->rd_gl, rgd);
+		return 0;
+	}
+
+	error = 0; /* someone else read in the rgrp; free it and ignore it */
+fail_glock:
+	gfs2_glock_put(rgd->rd_gl);
+
+fail:
+	kfree(rgd->rd_bits);
+	rgd->rd_bits = NULL;
+	kmem_cache_free(gfs2_rgrpd_cachep, rgd);
+	return error;
+}
+
+/**
+ * set_rgrp_preferences - Run all the rgrps, selecting some we prefer to use
+ * @sdp: the GFS2 superblock
+ *
+ * The purpose of this function is to select a subset of the resource groups
+ * and mark them as PREFERRED. We do it in such a way that each node prefers
+ * to use a unique set of rgrps to minimize glock contention.
+ */
+static void set_rgrp_preferences(struct gfs2_sbd *sdp)
+{
+	struct gfs2_rgrpd *rgd, *first;
+	int i;
+
+	/* Skip an initial number of rgrps, based on this node's journal ID.
+	   That should start each node out on its own set. */
+	rgd = gfs2_rgrpd_get_first(sdp);
+	for (i = 0; i < sdp->sd_lockstruct.ls_jid; i++)
+		rgd = gfs2_rgrpd_get_next(rgd);
+	first = rgd;
+
+	do {
+		rgd->rd_flags |= GFS2_RDF_PREFERRED;
+		for (i = 0; i < sdp->sd_journals; i++) {
+			rgd = gfs2_rgrpd_get_next(rgd);
+			if (!rgd || rgd == first)
+				break;
+		}
+	} while (rgd && rgd != first);
+}
+
+/**
+ * gfs2_ri_update - Pull in a new resource index from the disk
+ * @ip: pointer to 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);
+	int error;
+
+	do {
+		error = read_rindex_entry(ip);
+	} while (error == 0);
+
+	if (error < 0)
+		return error;
+
+	if (RB_EMPTY_ROOT(&sdp->sd_rindex_tree)) {
+		fs_err(sdp, "no resource groups found in the file system.\n");
+		return -ENOENT;
+	}
+	set_rgrp_preferences(sdp);
+
+	sdp->sd_rindex_uptodate = 1;
+	return 0;
+}
+
+/**
+ * gfs2_rindex_update - Update the rindex if required
+ * @sdp: The GFS2 superblock
+ *
+ * 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 succeess, error code otherwise
+ */
+
+int gfs2_rindex_update(struct gfs2_sbd *sdp)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
+	struct gfs2_glock *gl = ip->i_gl;
+	struct gfs2_holder ri_gh;
+	int error = 0;
+	int unlock_required = 0;
+
+	/* Read new copy from disk if we don't have the latest */
+	if (!sdp->sd_rindex_uptodate) {
+		if (!gfs2_glock_is_locked_by_me(gl)) {
+			error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, &ri_gh);
+			if (error)
+				return error;
+			unlock_required = 1;
+		}
+		if (!sdp->sd_rindex_uptodate)
+			error = gfs2_ri_update(ip);
+		if (unlock_required)
+			gfs2_glock_dq_uninit(&ri_gh);
+	}
+
+	return error;
+}
+
+static void gfs2_rgrp_in(struct gfs2_rgrpd *rgd, const void *buf)
+{
+	const struct gfs2_rgrp *str = buf;
+	u32 rg_flags;
+
+	rg_flags = be32_to_cpu(str->rg_flags);
+	rg_flags &= ~GFS2_RDF_MASK;
+	rgd->rd_flags &= GFS2_RDF_MASK;
+	rgd->rd_flags |= rg_flags;
+	rgd->rd_free = be32_to_cpu(str->rg_free);
+	rgd->rd_dinodes = be32_to_cpu(str->rg_dinodes);
+	rgd->rd_igeneration = be64_to_cpu(str->rg_igeneration);
+	/* rd_data0, rd_data and rd_bitbytes already set from rindex */
+}
+
+static void gfs2_rgrp_ondisk2lvb(struct gfs2_rgrp_lvb *rgl, const void *buf)
+{
+	const struct gfs2_rgrp *str = buf;
+
+	rgl->rl_magic = cpu_to_be32(GFS2_MAGIC);
+	rgl->rl_flags = str->rg_flags;
+	rgl->rl_free = str->rg_free;
+	rgl->rl_dinodes = str->rg_dinodes;
+	rgl->rl_igeneration = str->rg_igeneration;
+	rgl->__pad = 0UL;
+}
+
+static void gfs2_rgrp_out(struct gfs2_rgrpd *rgd, void *buf)
+{
+	struct gfs2_rgrpd *next = gfs2_rgrpd_get_next(rgd);
+	struct gfs2_rgrp *str = buf;
+	u32 crc;
+
+	str->rg_flags = cpu_to_be32(rgd->rd_flags & ~GFS2_RDF_MASK);
+	str->rg_free = cpu_to_be32(rgd->rd_free);
+	str->rg_dinodes = cpu_to_be32(rgd->rd_dinodes);
+	if (next == NULL)
+		str->rg_skip = 0;
+	else if (next->rd_addr > rgd->rd_addr)
+		str->rg_skip = cpu_to_be32(next->rd_addr - rgd->rd_addr);
+	str->rg_igeneration = cpu_to_be64(rgd->rd_igeneration);
+	str->rg_data0 = cpu_to_be64(rgd->rd_data0);
+	str->rg_data = cpu_to_be32(rgd->rd_data);
+	str->rg_bitbytes = cpu_to_be32(rgd->rd_bitbytes);
+	str->rg_crc = 0;
+	crc = gfs2_disk_hash(buf, sizeof(struct gfs2_rgrp));
+	str->rg_crc = cpu_to_be32(crc);
+
+	memset(&str->rg_reserved, 0, sizeof(str->rg_reserved));
+	gfs2_rgrp_ondisk2lvb(rgd->rd_rgl, buf);
+}
+
+static int gfs2_rgrp_lvb_valid(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_rgrp_lvb *rgl = rgd->rd_rgl;
+	struct gfs2_rgrp *str = (struct gfs2_rgrp *)rgd->rd_bits[0].bi_bh->b_data;
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	int valid = 1;
+
+	if (rgl->rl_flags != str->rg_flags) {
+		fs_warn(sdp, "GFS2: rgd: %llu lvb flag mismatch %u/%u",
+			(unsigned long long)rgd->rd_addr,
+		       be32_to_cpu(rgl->rl_flags), be32_to_cpu(str->rg_flags));
+		valid = 0;
+	}
+	if (rgl->rl_free != str->rg_free) {
+		fs_warn(sdp, "GFS2: rgd: %llu lvb free mismatch %u/%u",
+			(unsigned long long)rgd->rd_addr,
+			be32_to_cpu(rgl->rl_free), be32_to_cpu(str->rg_free));
+		valid = 0;
+	}
+	if (rgl->rl_dinodes != str->rg_dinodes) {
+		fs_warn(sdp, "GFS2: rgd: %llu lvb dinode mismatch %u/%u",
+			(unsigned long long)rgd->rd_addr,
+			be32_to_cpu(rgl->rl_dinodes),
+			be32_to_cpu(str->rg_dinodes));
+		valid = 0;
+	}
+	if (rgl->rl_igeneration != str->rg_igeneration) {
+		fs_warn(sdp, "GFS2: rgd: %llu lvb igen mismatch %llu/%llu",
+			(unsigned long long)rgd->rd_addr,
+			(unsigned long long)be64_to_cpu(rgl->rl_igeneration),
+			(unsigned long long)be64_to_cpu(str->rg_igeneration));
+		valid = 0;
+	}
+	return valid;
+}
+
+static u32 count_unlinked(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_bitmap *bi;
+	const u32 length = rgd->rd_length;
+	const u8 *buffer = NULL;
+	u32 i, goal, count = 0;
+
+	for (i = 0, bi = rgd->rd_bits; i < length; i++, bi++) {
+		goal = 0;
+		buffer = bi->bi_bh->b_data + bi->bi_offset;
+		WARN_ON(!buffer_uptodate(bi->bi_bh));
+		while (goal < bi->bi_blocks) {
+			goal = gfs2_bitfit(buffer, bi->bi_bytes, goal,
+					   GFS2_BLKST_UNLINKED);
+			if (goal == BFITNOENT)
+				break;
+			count++;
+			goal++;
+		}
+	}
+
+	return count;
+}
+
+
+/**
+ * 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_brelse() to free the bitmaps.
+ *
+ * Returns: errno
+ */
+
+static 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_length;
+	struct gfs2_bitmap *bi;
+	unsigned int x, y;
+	int error;
+
+	if (rgd->rd_bits[0].bi_bh != NULL)
+		return 0;
+
+	for (x = 0; x < length; x++) {
+		bi = rgd->rd_bits + x;
+		error = gfs2_meta_read(gl, rgd->rd_addr + x, 0, 0, &bi->bi_bh);
+		if (error)
+			goto fail;
+	}
+
+	for (y = length; y--;) {
+		bi = rgd->rd_bits + y;
+		error = gfs2_meta_wait(sdp, bi->bi_bh);
+		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_flags & GFS2_RDF_UPTODATE)) {
+		for (x = 0; x < length; x++)
+			clear_bit(GBF_FULL, &rgd->rd_bits[x].bi_flags);
+		gfs2_rgrp_in(rgd, (rgd->rd_bits[0].bi_bh)->b_data);
+		rgd->rd_flags |= (GFS2_RDF_UPTODATE | GFS2_RDF_CHECK);
+		rgd->rd_free_clone = rgd->rd_free;
+		/* max out the rgrp allocation failure point */
+		rgd->rd_extfail_pt = rgd->rd_free;
+	}
+	if (cpu_to_be32(GFS2_MAGIC) != rgd->rd_rgl->rl_magic) {
+		rgd->rd_rgl->rl_unlinked = cpu_to_be32(count_unlinked(rgd));
+		gfs2_rgrp_ondisk2lvb(rgd->rd_rgl,
+				     rgd->rd_bits[0].bi_bh->b_data);
+	}
+	else if (sdp->sd_args.ar_rgrplvb) {
+		if (!gfs2_rgrp_lvb_valid(rgd)){
+			gfs2_consist_rgrpd(rgd);
+			error = -EIO;
+			goto fail;
+		}
+		if (rgd->rd_rgl->rl_unlinked == 0)
+			rgd->rd_flags &= ~GFS2_RDF_CHECK;
+	}
+	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);
+	}
+
+	return error;
+}
+
+static int update_rgrp_lvb(struct gfs2_rgrpd *rgd)
+{
+	u32 rl_flags;
+
+	if (rgd->rd_flags & GFS2_RDF_UPTODATE)
+		return 0;
+
+	if (cpu_to_be32(GFS2_MAGIC) != rgd->rd_rgl->rl_magic)
+		return gfs2_rgrp_bh_get(rgd);
+
+	rl_flags = be32_to_cpu(rgd->rd_rgl->rl_flags);
+	rl_flags &= ~GFS2_RDF_MASK;
+	rgd->rd_flags &= GFS2_RDF_MASK;
+	rgd->rd_flags |= (rl_flags | GFS2_RDF_CHECK);
+	if (rgd->rd_rgl->rl_unlinked == 0)
+		rgd->rd_flags &= ~GFS2_RDF_CHECK;
+	rgd->rd_free = be32_to_cpu(rgd->rd_rgl->rl_free);
+	rgd->rd_free_clone = rgd->rd_free;
+	/* max out the rgrp allocation failure point */
+	rgd->rd_extfail_pt = rgd->rd_free;
+	rgd->rd_dinodes = be32_to_cpu(rgd->rd_rgl->rl_dinodes);
+	rgd->rd_igeneration = be64_to_cpu(rgd->rd_rgl->rl_igeneration);
+	return 0;
+}
+
+int gfs2_rgrp_go_lock(struct gfs2_holder *gh)
+{
+	struct gfs2_rgrpd *rgd = gh->gh_gl->gl_object;
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+
+	if (gh->gh_flags & GL_SKIP && sdp->sd_args.ar_rgrplvb)
+		return 0;
+	return gfs2_rgrp_bh_get(rgd);
+}
+
+/**
+ * gfs2_rgrp_brelse - Release RG bitmaps read in with gfs2_rgrp_bh_get()
+ * @rgd: The resource group
+ *
+ */
+
+void gfs2_rgrp_brelse(struct gfs2_rgrpd *rgd)
+{
+	int x, length = rgd->rd_length;
+
+	for (x = 0; x < length; x++) {
+		struct gfs2_bitmap *bi = rgd->rd_bits + x;
+		if (bi->bi_bh) {
+			brelse(bi->bi_bh);
+			bi->bi_bh = NULL;
+		}
+	}
+}
+
+int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
+			     struct buffer_head *bh,
+			     const struct gfs2_bitmap *bi, unsigned minlen, u64 *ptrimmed)
+{
+	struct super_block *sb = sdp->sd_vfs;
+	u64 blk;
+	sector_t start = 0;
+	sector_t nr_blks = 0;
+	int rv;
+	unsigned int x;
+	u32 trimmed = 0;
+	u8 diff;
+
+	for (x = 0; x < bi->bi_bytes; x++) {
+		const u8 *clone = bi->bi_clone ? bi->bi_clone : bi->bi_bh->b_data;
+		clone += bi->bi_offset;
+		clone += x;
+		if (bh) {
+			const u8 *orig = bh->b_data + bi->bi_offset + x;
+			diff = ~(*orig | (*orig >> 1)) & (*clone | (*clone >> 1));
+		} else {
+			diff = ~(*clone | (*clone >> 1));
+		}
+		diff &= 0x55;
+		if (diff == 0)
+			continue;
+		blk = offset + ((bi->bi_start + x) * GFS2_NBBY);
+		while(diff) {
+			if (diff & 1) {
+				if (nr_blks == 0)
+					goto start_new_extent;
+				if ((start + nr_blks) != blk) {
+					if (nr_blks >= minlen) {
+						rv = sb_issue_discard(sb,
+							start, nr_blks,
+							GFP_NOFS, 0);
+						if (rv)
+							goto fail;
+						trimmed += nr_blks;
+					}
+					nr_blks = 0;
+start_new_extent:
+					start = blk;
+				}
+				nr_blks++;
+			}
+			diff >>= 2;
+			blk++;
+		}
+	}
+	if (nr_blks >= minlen) {
+		rv = sb_issue_discard(sb, start, nr_blks, GFP_NOFS, 0);
+		if (rv)
+			goto fail;
+		trimmed += nr_blks;
+	}
+	if (ptrimmed)
+		*ptrimmed = trimmed;
+	return 0;
+
+fail:
+	if (sdp->sd_args.ar_discard)
+		fs_warn(sdp, "error %d on discard request, turning discards off for this filesystem\n", rv);
+	sdp->sd_args.ar_discard = 0;
+	return -EIO;
+}
+
+/**
+ * gfs2_fitrim - Generate discard requests for unused bits of the filesystem
+ * @filp: Any file on the filesystem
+ * @argp: Pointer to the arguments (also used to pass result)
+ *
+ * Returns: 0 on success, otherwise error code
+ */
+
+int gfs2_fitrim(struct file *filp, void __user *argp)
+{
+	struct inode *inode = file_inode(filp);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct request_queue *q = bdev_get_queue(sdp->sd_vfs->s_bdev);
+	struct buffer_head *bh;
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_rgrpd *rgd_end;
+	struct gfs2_holder gh;
+	struct fstrim_range r;
+	int ret = 0;
+	u64 amt;
+	u64 trimmed = 0;
+	u64 start, end, minlen;
+	unsigned int x;
+	unsigned bs_shift = sdp->sd_sb.sb_bsize_shift;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
+		return -EROFS;
+
+	if (!blk_queue_discard(q))
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&r, argp, sizeof(r)))
+		return -EFAULT;
+
+	ret = gfs2_rindex_update(sdp);
+	if (ret)
+		return ret;
+
+	start = r.start >> bs_shift;
+	end = start + (r.len >> bs_shift);
+	minlen = max_t(u64, r.minlen, sdp->sd_sb.sb_bsize);
+	minlen = max_t(u64, minlen,
+		       q->limits.discard_granularity) >> bs_shift;
+
+	if (end <= start || minlen > sdp->sd_max_rg_data)
+		return -EINVAL;
+
+	rgd = gfs2_blk2rgrpd(sdp, start, 0);
+	rgd_end = gfs2_blk2rgrpd(sdp, end, 0);
+
+	if ((gfs2_rgrpd_get_first(sdp) == gfs2_rgrpd_get_next(rgd_end))
+	    && (start > rgd_end->rd_data0 + rgd_end->rd_data))
+		return -EINVAL; /* start is beyond the end of the fs */
+
+	while (1) {
+
+		ret = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
+		if (ret)
+			goto out;
+
+		if (!(rgd->rd_flags & GFS2_RGF_TRIMMED)) {
+			/* Trim each bitmap in the rgrp */
+			for (x = 0; x < rgd->rd_length; x++) {
+				struct gfs2_bitmap *bi = rgd->rd_bits + x;
+				ret = gfs2_rgrp_send_discards(sdp,
+						rgd->rd_data0, NULL, bi, minlen,
+						&amt);
+				if (ret) {
+					gfs2_glock_dq_uninit(&gh);
+					goto out;
+				}
+				trimmed += amt;
+			}
+
+			/* Mark rgrp as having been trimmed */
+			ret = gfs2_trans_begin(sdp, RES_RG_HDR, 0);
+			if (ret == 0) {
+				bh = rgd->rd_bits[0].bi_bh;
+				rgd->rd_flags |= GFS2_RGF_TRIMMED;
+				gfs2_trans_add_meta(rgd->rd_gl, bh);
+				gfs2_rgrp_out(rgd, bh->b_data);
+				gfs2_trans_end(sdp);
+			}
+		}
+		gfs2_glock_dq_uninit(&gh);
+
+		if (rgd == rgd_end)
+			break;
+
+		rgd = gfs2_rgrpd_get_next(rgd);
+	}
+
+out:
+	r.len = trimmed << bs_shift;
+	if (copy_to_user(argp, &r, sizeof(r)))
+		return -EFAULT;
+
+	return ret;
+}
+
+/**
+ * rs_insert - insert a new multi-block reservation into the rgrp's rb_tree
+ * @ip: the inode structure
+ *
+ */
+static void rs_insert(struct gfs2_inode *ip)
+{
+	struct rb_node **newn, *parent = NULL;
+	int rc;
+	struct gfs2_blkreserv *rs = &ip->i_res;
+	struct gfs2_rgrpd *rgd = rs->rs_rbm.rgd;
+	u64 fsblock = gfs2_rbm_to_block(&rs->rs_rbm);
+
+	BUG_ON(gfs2_rs_active(rs));
+
+	spin_lock(&rgd->rd_rsspin);
+	newn = &rgd->rd_rstree.rb_node;
+	while (*newn) {
+		struct gfs2_blkreserv *cur =
+			rb_entry(*newn, struct gfs2_blkreserv, rs_node);
+
+		parent = *newn;
+		rc = rs_cmp(fsblock, rs->rs_free, cur);
+		if (rc > 0)
+			newn = &((*newn)->rb_right);
+		else if (rc < 0)
+			newn = &((*newn)->rb_left);
+		else {
+			spin_unlock(&rgd->rd_rsspin);
+			WARN_ON(1);
+			return;
+		}
+	}
+
+	rb_link_node(&rs->rs_node, parent, newn);
+	rb_insert_color(&rs->rs_node, &rgd->rd_rstree);
+
+	/* Do our rgrp accounting for the reservation */
+	rgd->rd_reserved += rs->rs_free; /* blocks reserved */
+	spin_unlock(&rgd->rd_rsspin);
+	trace_gfs2_rs(rs, TRACE_RS_INSERT);
+}
+
+/**
+ * rgd_free - return the number of free blocks we can allocate.
+ * @rgd: the resource group
+ *
+ * This function returns the number of free blocks for an rgrp.
+ * That's the clone-free blocks (blocks that are free, not including those
+ * still being used for unlinked files that haven't been deleted.)
+ *
+ * It also subtracts any blocks reserved by someone else, but does not
+ * include free blocks that are still part of our current reservation,
+ * because obviously we can (and will) allocate them.
+ */
+static inline u32 rgd_free(struct gfs2_rgrpd *rgd, struct gfs2_blkreserv *rs)
+{
+	u32 tot_reserved, tot_free;
+
+	if (WARN_ON_ONCE(rgd->rd_reserved < rs->rs_free))
+		return 0;
+	tot_reserved = rgd->rd_reserved - rs->rs_free;
+
+	if (rgd->rd_free_clone < tot_reserved)
+		tot_reserved = 0;
+
+	tot_free = rgd->rd_free_clone - tot_reserved;
+
+	return tot_free;
+}
+
+/**
+ * rg_mblk_search - find a group of multiple free blocks to form a reservation
+ * @rgd: the resource group descriptor
+ * @ip: pointer to the inode for which we're reserving blocks
+ * @ap: the allocation parameters
+ *
+ */
+
+static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
+			   const struct gfs2_alloc_parms *ap)
+{
+	struct gfs2_rbm rbm = { .rgd = rgd, };
+	u64 goal;
+	struct gfs2_blkreserv *rs = &ip->i_res;
+	u32 extlen;
+	u32 free_blocks = rgd_free(rgd, rs);
+	int ret;
+	struct inode *inode = &ip->i_inode;
+
+	if (S_ISDIR(inode->i_mode))
+		extlen = 1;
+	else {
+		extlen = max_t(u32, atomic_read(&ip->i_sizehint), ap->target);
+		extlen = clamp(extlen, (u32)RGRP_RSRV_MINBLKS, free_blocks);
+	}
+	if ((rgd->rd_free_clone < rgd->rd_reserved) || (free_blocks < extlen))
+		return;
+
+	/* Find bitmap block that contains bits for goal block */
+	if (rgrp_contains_block(rgd, ip->i_goal))
+		goal = ip->i_goal;
+	else
+		goal = rgd->rd_last_alloc + rgd->rd_data0;
+
+	if (WARN_ON(gfs2_rbm_from_block(&rbm, goal)))
+		return;
+
+	ret = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, &extlen, ip, true);
+	if (ret == 0) {
+		rs->rs_rbm = rbm;
+		rs->rs_free = extlen;
+		rs_insert(ip);
+	} else {
+		if (goal == rgd->rd_last_alloc + rgd->rd_data0)
+			rgd->rd_last_alloc = 0;
+	}
+}
+
+/**
+ * gfs2_next_unreserved_block - Return next block that is not reserved
+ * @rgd: The resource group
+ * @block: The starting block
+ * @length: The required length
+ * @ip: Ignore any reservations for this inode
+ *
+ * If the block does not appear in any reservation, then return the
+ * block number unchanged. If it does appear in the reservation, then
+ * keep looking through the tree of reservations in order to find the
+ * first block number which is not reserved.
+ */
+
+static u64 gfs2_next_unreserved_block(struct gfs2_rgrpd *rgd, u64 block,
+				      u32 length,
+				      const struct gfs2_inode *ip)
+{
+	struct gfs2_blkreserv *rs;
+	struct rb_node *n;
+	int rc;
+
+	spin_lock(&rgd->rd_rsspin);
+	n = rgd->rd_rstree.rb_node;
+	while (n) {
+		rs = rb_entry(n, struct gfs2_blkreserv, rs_node);
+		rc = rs_cmp(block, length, rs);
+		if (rc < 0)
+			n = n->rb_left;
+		else if (rc > 0)
+			n = n->rb_right;
+		else
+			break;
+	}
+
+	if (n) {
+		while ((rs_cmp(block, length, rs) == 0) && (&ip->i_res != rs)) {
+			block = gfs2_rbm_to_block(&rs->rs_rbm) + rs->rs_free;
+			n = n->rb_right;
+			if (n == NULL)
+				break;
+			rs = rb_entry(n, struct gfs2_blkreserv, rs_node);
+		}
+	}
+
+	spin_unlock(&rgd->rd_rsspin);
+	return block;
+}
+
+/**
+ * gfs2_reservation_check_and_update - Check for reservations during block alloc
+ * @rbm: The current position in the resource group
+ * @ip: The inode for which we are searching for blocks
+ * @minext: The minimum extent length
+ * @maxext: A pointer to the maximum extent structure
+ *
+ * This checks the current position in the rgrp to see whether there is
+ * a reservation covering this block. If not then this function is a
+ * no-op. If there is, then the position is moved to the end of the
+ * contiguous reservation(s) so that we are pointing at the first
+ * non-reserved block.
+ *
+ * Returns: 0 if no reservation, 1 if @rbm has changed, otherwise an error
+ */
+
+static int gfs2_reservation_check_and_update(struct gfs2_rbm *rbm,
+					     const struct gfs2_inode *ip,
+					     u32 minext,
+					     struct gfs2_extent *maxext)
+{
+	u64 block = gfs2_rbm_to_block(rbm);
+	u32 extlen = 1;
+	u64 nblock;
+	int ret;
+
+	/*
+	 * If we have a minimum extent length, then skip over any extent
+	 * which is less than the min extent length in size.
+	 */
+	if (minext > 1) {
+		extlen = gfs2_free_extlen(rbm, minext);
+		if (extlen <= maxext->len)
+			goto fail;
+	}
+
+	/*
+	 * Check the extent which has been found against the reservations
+	 * and skip if parts of it are already reserved
+	 */
+	nblock = gfs2_next_unreserved_block(rbm->rgd, block, extlen, ip);
+	if (nblock == block) {
+		if (!minext || extlen >= minext)
+			return 0;
+
+		if (extlen > maxext->len) {
+			maxext->len = extlen;
+			maxext->rbm = *rbm;
+		}
+fail:
+		nblock = block + extlen;
+	}
+	ret = gfs2_rbm_from_block(rbm, nblock);
+	if (ret < 0)
+		return ret;
+	return 1;
+}
+
+/**
+ * gfs2_rbm_find - Look for blocks of a particular state
+ * @rbm: Value/result starting position and final position
+ * @state: The state which we want to find
+ * @minext: Pointer to the requested extent length
+ *          This is updated to be the actual reservation size.
+ * @ip: If set, check for reservations
+ * @nowrap: Stop looking at the end of the rgrp, rather than wrapping
+ *          around until we've reached the starting point.
+ *
+ * Side effects:
+ * - If looking for free blocks, we set GBF_FULL on each bitmap which
+ *   has no free blocks in it.
+ * - If looking for free blocks, we set rd_extfail_pt on each rgrp which
+ *   has come up short on a free block search.
+ *
+ * Returns: 0 on success, -ENOSPC if there is no block of the requested state
+ */
+
+static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
+			 const struct gfs2_inode *ip, bool nowrap)
+{
+	bool scan_from_start = rbm->bii == 0 && rbm->offset == 0;
+	struct buffer_head *bh;
+	int last_bii;
+	u32 offset;
+	u8 *buffer;
+	bool wrapped = false;
+	int ret;
+	struct gfs2_bitmap *bi;
+	struct gfs2_extent maxext = { .rbm.rgd = rbm->rgd, };
+
+	/*
+	 * Determine the last bitmap to search.  If we're not starting at the
+	 * beginning of a bitmap, we need to search that bitmap twice to scan
+	 * the entire resource group.
+	 */
+	last_bii = rbm->bii - (rbm->offset == 0);
+
+	while(1) {
+		bi = rbm_bi(rbm);
+		if (test_bit(GBF_FULL, &bi->bi_flags) &&
+		    (state == GFS2_BLKST_FREE))
+			goto next_bitmap;
+
+		bh = bi->bi_bh;
+		buffer = bh->b_data + bi->bi_offset;
+		WARN_ON(!buffer_uptodate(bh));
+		if (state != GFS2_BLKST_UNLINKED && bi->bi_clone)
+			buffer = bi->bi_clone + bi->bi_offset;
+		offset = gfs2_bitfit(buffer, bi->bi_bytes, rbm->offset, state);
+		if (offset == BFITNOENT) {
+			if (state == GFS2_BLKST_FREE && rbm->offset == 0)
+				set_bit(GBF_FULL, &bi->bi_flags);
+			goto next_bitmap;
+		}
+		rbm->offset = offset;
+		if (ip == NULL)
+			return 0;
+
+		ret = gfs2_reservation_check_and_update(rbm, ip, *minext,
+							&maxext);
+		if (ret == 0)
+			return 0;
+		if (ret > 0)
+			goto next_iter;
+		if (ret == -E2BIG) {
+			rbm->bii = 0;
+			rbm->offset = 0;
+			goto res_covered_end_of_rgrp;
+		}
+		return ret;
+
+next_bitmap:	/* Find next bitmap in the rgrp */
+		rbm->offset = 0;
+		rbm->bii++;
+		if (rbm->bii == rbm->rgd->rd_length)
+			rbm->bii = 0;
+res_covered_end_of_rgrp:
+		if (rbm->bii == 0) {
+			if (wrapped)
+				break;
+			wrapped = true;
+			if (nowrap)
+				break;
+		}
+next_iter:
+		/* Have we scanned the entire resource group? */
+		if (wrapped && rbm->bii > last_bii)
+			break;
+	}
+
+	if (state != GFS2_BLKST_FREE)
+		return -ENOSPC;
+
+	/* If the extent was too small, and it's smaller than the smallest
+	   to have failed before, remember for future reference that it's
+	   useless to search this rgrp again for this amount or more. */
+	if (wrapped && (scan_from_start || rbm->bii > last_bii) &&
+	    *minext < rbm->rgd->rd_extfail_pt)
+		rbm->rgd->rd_extfail_pt = *minext - 1;
+
+	/* If the maximum extent we found is big enough to fulfill the
+	   minimum requirements, use it anyway. */
+	if (maxext.len) {
+		*rbm = maxext.rbm;
+		*minext = maxext.len;
+		return 0;
+	}
+
+	return -ENOSPC;
+}
+
+/**
+ * try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes
+ * @rgd: The rgrp
+ * @last_unlinked: block address of the last dinode we unlinked
+ * @skip: block address we should explicitly not unlink
+ *
+ * Returns: 0 if no error
+ *          The inode, if one has been found, in inode.
+ */
+
+static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip)
+{
+	u64 block;
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	struct gfs2_glock *gl;
+	struct gfs2_inode *ip;
+	int error;
+	int found = 0;
+	struct gfs2_rbm rbm = { .rgd = rgd, .bii = 0, .offset = 0 };
+
+	while (1) {
+		error = gfs2_rbm_find(&rbm, GFS2_BLKST_UNLINKED, NULL, NULL,
+				      true);
+		if (error == -ENOSPC)
+			break;
+		if (WARN_ON_ONCE(error))
+			break;
+
+		block = gfs2_rbm_to_block(&rbm);
+		if (gfs2_rbm_from_block(&rbm, block + 1))
+			break;
+		if (*last_unlinked != NO_BLOCK && block <= *last_unlinked)
+			continue;
+		if (block == skip)
+			continue;
+		*last_unlinked = block;
+
+		error = gfs2_glock_get(sdp, block, &gfs2_iopen_glops, CREATE, &gl);
+		if (error)
+			continue;
+
+		/* If the inode is already in cache, we can ignore it here
+		 * because the existing inode disposal code will deal with
+		 * it when all refs have gone away. Accessing gl_object like
+		 * this is not safe in general. Here it is ok because we do
+		 * not dereference the pointer, and we only need an approx
+		 * answer to whether it is NULL or not.
+		 */
+		ip = gl->gl_object;
+
+		if (ip || !gfs2_queue_delete_work(gl, 0))
+			gfs2_glock_put(gl);
+		else
+			found++;
+
+		/* Limit reclaim to sensible number of tasks */
+		if (found > NR_CPUS)
+			return;
+	}
+
+	rgd->rd_flags &= ~GFS2_RDF_CHECK;
+	return;
+}
+
+/**
+ * gfs2_rgrp_congested - Use stats to figure out whether an rgrp is congested
+ * @rgd: The rgrp in question
+ * @loops: An indication of how picky we can be (0=very, 1=less so)
+ *
+ * This function uses the recently added glock statistics in order to
+ * figure out whether a parciular resource group is suffering from
+ * contention from multiple nodes. This is done purely on the basis
+ * of timings, since this is the only data we have to work with and
+ * our aim here is to reject a resource group which is highly contended
+ * but (very important) not to do this too often in order to ensure that
+ * we do not land up introducing fragmentation by changing resource
+ * groups when not actually required.
+ *
+ * The calculation is fairly simple, we want to know whether the SRTTB
+ * (i.e. smoothed round trip time for blocking operations) to acquire
+ * the lock for this rgrp's glock is significantly greater than the
+ * time taken for resource groups on average. We introduce a margin in
+ * the form of the variable @var which is computed as the sum of the two
+ * respective variences, and multiplied by a factor depending on @loops
+ * and whether we have a lot of data to base the decision on. This is
+ * then tested against the square difference of the means in order to
+ * decide whether the result is statistically significant or not.
+ *
+ * Returns: A boolean verdict on the congestion status
+ */
+
+static bool gfs2_rgrp_congested(const struct gfs2_rgrpd *rgd, int loops)
+{
+	const struct gfs2_glock *gl = rgd->rd_gl;
+	const struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+	struct gfs2_lkstats *st;
+	u64 r_dcount, l_dcount;
+	u64 l_srttb, a_srttb = 0;
+	s64 srttb_diff;
+	u64 sqr_diff;
+	u64 var;
+	int cpu, nonzero = 0;
+
+	preempt_disable();
+	for_each_present_cpu(cpu) {
+		st = &per_cpu_ptr(sdp->sd_lkstats, cpu)->lkstats[LM_TYPE_RGRP];
+		if (st->stats[GFS2_LKS_SRTTB]) {
+			a_srttb += st->stats[GFS2_LKS_SRTTB];
+			nonzero++;
+		}
+	}
+	st = &this_cpu_ptr(sdp->sd_lkstats)->lkstats[LM_TYPE_RGRP];
+	if (nonzero)
+		do_div(a_srttb, nonzero);
+	r_dcount = st->stats[GFS2_LKS_DCOUNT];
+	var = st->stats[GFS2_LKS_SRTTVARB] +
+	      gl->gl_stats.stats[GFS2_LKS_SRTTVARB];
+	preempt_enable();
+
+	l_srttb = gl->gl_stats.stats[GFS2_LKS_SRTTB];
+	l_dcount = gl->gl_stats.stats[GFS2_LKS_DCOUNT];
+
+	if ((l_dcount < 1) || (r_dcount < 1) || (a_srttb == 0))
+		return false;
+
+	srttb_diff = a_srttb - l_srttb;
+	sqr_diff = srttb_diff * srttb_diff;
+
+	var *= 2;
+	if (l_dcount < 8 || r_dcount < 8)
+		var *= 2;
+	if (loops == 1)
+		var *= 2;
+
+	return ((srttb_diff < 0) && (sqr_diff > var));
+}
+
+/**
+ * gfs2_rgrp_used_recently
+ * @rs: The block reservation with the rgrp to test
+ * @msecs: The time limit in milliseconds
+ *
+ * Returns: True if the rgrp glock has been used within the time limit
+ */
+static bool gfs2_rgrp_used_recently(const struct gfs2_blkreserv *rs,
+				    u64 msecs)
+{
+	u64 tdiff;
+
+	tdiff = ktime_to_ns(ktime_sub(ktime_get_real(),
+                            rs->rs_rbm.rgd->rd_gl->gl_dstamp));
+
+	return tdiff > (msecs * 1000 * 1000);
+}
+
+static u32 gfs2_orlov_skip(const struct gfs2_inode *ip)
+{
+	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	u32 skip;
+
+	get_random_bytes(&skip, sizeof(skip));
+	return skip % sdp->sd_rgrps;
+}
+
+static bool gfs2_select_rgrp(struct gfs2_rgrpd **pos, const struct gfs2_rgrpd *begin)
+{
+	struct gfs2_rgrpd *rgd = *pos;
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+
+	rgd = gfs2_rgrpd_get_next(rgd);
+	if (rgd == NULL)
+		rgd = gfs2_rgrpd_get_first(sdp);
+	*pos = rgd;
+	if (rgd != begin) /* If we didn't wrap */
+		return true;
+	return false;
+}
+
+/**
+ * fast_to_acquire - determine if a resource group will be fast to acquire
+ *
+ * If this is one of our preferred rgrps, it should be quicker to acquire,
+ * because we tried to set ourselves up as dlm lock master.
+ */
+static inline int fast_to_acquire(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_glock *gl = rgd->rd_gl;
+
+	if (gl->gl_state != LM_ST_UNLOCKED && list_empty(&gl->gl_holders) &&
+	    !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
+	    !test_bit(GLF_DEMOTE, &gl->gl_flags))
+		return 1;
+	if (rgd->rd_flags & GFS2_RDF_PREFERRED)
+		return 1;
+	return 0;
+}
+
+/**
+ * gfs2_inplace_reserve - Reserve space in the filesystem
+ * @ip: the inode to reserve space for
+ * @ap: the allocation parameters
+ *
+ * We try our best to find an rgrp that has at least ap->target blocks
+ * available. After a couple of passes (loops == 2), the prospects of finding
+ * such an rgrp diminish. At this stage, we return the first rgrp that has
+ * at least ap->min_target blocks available. Either way, we set ap->allowed to
+ * the number of blocks available in the chosen rgrp.
+ *
+ * Returns: 0 on success,
+ *          -ENOMEM if a suitable rgrp can't be found
+ *          errno otherwise
+ */
+
+int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_rgrpd *begin = NULL;
+	struct gfs2_blkreserv *rs = &ip->i_res;
+	int error = 0, rg_locked, flags = 0;
+	u64 last_unlinked = NO_BLOCK;
+	int loops = 0;
+	u32 free_blocks, skip = 0;
+
+	if (sdp->sd_args.ar_rgrplvb)
+		flags |= GL_SKIP;
+	if (gfs2_assert_warn(sdp, ap->target))
+		return -EINVAL;
+	if (gfs2_rs_active(rs)) {
+		begin = rs->rs_rbm.rgd;
+	} else if (rs->rs_rbm.rgd &&
+		   rgrp_contains_block(rs->rs_rbm.rgd, ip->i_goal)) {
+		begin = rs->rs_rbm.rgd;
+	} else {
+		check_and_update_goal(ip);
+		rs->rs_rbm.rgd = begin = gfs2_blk2rgrpd(sdp, ip->i_goal, 1);
+	}
+	if (S_ISDIR(ip->i_inode.i_mode) && (ap->aflags & GFS2_AF_ORLOV))
+		skip = gfs2_orlov_skip(ip);
+	if (rs->rs_rbm.rgd == NULL)
+		return -EBADSLT;
+
+	while (loops < 3) {
+		rg_locked = 1;
+
+		if (!gfs2_glock_is_locked_by_me(rs->rs_rbm.rgd->rd_gl)) {
+			rg_locked = 0;
+			if (skip && skip--)
+				goto next_rgrp;
+			if (!gfs2_rs_active(rs)) {
+				if (loops == 0 &&
+				    !fast_to_acquire(rs->rs_rbm.rgd))
+					goto next_rgrp;
+				if ((loops < 2) &&
+				    gfs2_rgrp_used_recently(rs, 1000) &&
+				    gfs2_rgrp_congested(rs->rs_rbm.rgd, loops))
+					goto next_rgrp;
+			}
+			error = gfs2_glock_nq_init(rs->rs_rbm.rgd->rd_gl,
+						   LM_ST_EXCLUSIVE, flags,
+						   &ip->i_rgd_gh);
+			if (unlikely(error))
+				return error;
+			if (!gfs2_rs_active(rs) && (loops < 2) &&
+			    gfs2_rgrp_congested(rs->rs_rbm.rgd, loops))
+				goto skip_rgrp;
+			if (sdp->sd_args.ar_rgrplvb) {
+				error = update_rgrp_lvb(rs->rs_rbm.rgd);
+				if (unlikely(error)) {
+					gfs2_glock_dq_uninit(&ip->i_rgd_gh);
+					return error;
+				}
+			}
+		}
+
+		/* Skip unusable resource groups */
+		if ((rs->rs_rbm.rgd->rd_flags & (GFS2_RGF_NOALLOC |
+						 GFS2_RDF_ERROR)) ||
+		    (loops == 0 && ap->target > rs->rs_rbm.rgd->rd_extfail_pt))
+			goto skip_rgrp;
+
+		if (sdp->sd_args.ar_rgrplvb)
+			gfs2_rgrp_bh_get(rs->rs_rbm.rgd);
+
+		/* Get a reservation if we don't already have one */
+		if (!gfs2_rs_active(rs))
+			rg_mblk_search(rs->rs_rbm.rgd, ip, ap);
+
+		/* Skip rgrps when we can't get a reservation on first pass */
+		if (!gfs2_rs_active(rs) && (loops < 1))
+			goto check_rgrp;
+
+		/* If rgrp has enough free space, use it */
+		free_blocks = rgd_free(rs->rs_rbm.rgd, rs);
+		if (free_blocks >= ap->target ||
+		    (loops == 2 && ap->min_target &&
+		     free_blocks >= ap->min_target)) {
+			ap->allowed = free_blocks;
+			return 0;
+		}
+check_rgrp:
+		/* Check for unlinked inodes which can be reclaimed */
+		if (rs->rs_rbm.rgd->rd_flags & GFS2_RDF_CHECK)
+			try_rgrp_unlink(rs->rs_rbm.rgd, &last_unlinked,
+					ip->i_no_addr);
+skip_rgrp:
+		/* Drop reservation, if we couldn't use reserved rgrp */
+		if (gfs2_rs_active(rs))
+			gfs2_rs_deltree(rs);
+
+		/* Unlock rgrp if required */
+		if (!rg_locked)
+			gfs2_glock_dq_uninit(&ip->i_rgd_gh);
+next_rgrp:
+		/* Find the next rgrp, and continue looking */
+		if (gfs2_select_rgrp(&rs->rs_rbm.rgd, begin))
+			continue;
+		if (skip)
+			continue;
+
+		/* If we've scanned all the rgrps, but found no free blocks
+		 * then this checks for some less likely conditions before
+		 * trying again.
+		 */
+		loops++;
+		/* Check that fs hasn't grown if writing to rindex */
+		if (ip == GFS2_I(sdp->sd_rindex) && !sdp->sd_rindex_uptodate) {
+			error = gfs2_ri_update(ip);
+			if (error)
+				return error;
+		}
+		/* Flushing the log may release space */
+		if (loops == 2)
+			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
+				       GFS2_LFC_INPLACE_RESERVE);
+	}
+
+	return -ENOSPC;
+}
+
+/**
+ * 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)
+{
+	if (gfs2_holder_initialized(&ip->i_rgd_gh))
+		gfs2_glock_dq_uninit(&ip->i_rgd_gh);
+}
+
+/**
+ * gfs2_alloc_extent - allocate an extent from a given bitmap
+ * @rbm: the resource group information
+ * @dinode: TRUE if the first block we allocate is for a dinode
+ * @n: The extent length (value/result)
+ *
+ * Add the bitmap buffer to the transaction.
+ * Set the found bits to @new_state to change block's allocation state.
+ */
+static void gfs2_alloc_extent(const struct gfs2_rbm *rbm, bool dinode,
+			     unsigned int *n)
+{
+	struct gfs2_rbm pos = { .rgd = rbm->rgd, };
+	const unsigned int elen = *n;
+	u64 block;
+	int ret;
+
+	*n = 1;
+	block = gfs2_rbm_to_block(rbm);
+	gfs2_trans_add_meta(rbm->rgd->rd_gl, rbm_bi(rbm)->bi_bh);
+	gfs2_setbit(rbm, true, dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
+	block++;
+	while (*n < elen) {
+		ret = gfs2_rbm_from_block(&pos, block);
+		if (ret || gfs2_testbit(&pos, true) != GFS2_BLKST_FREE)
+			break;
+		gfs2_trans_add_meta(pos.rgd->rd_gl, rbm_bi(&pos)->bi_bh);
+		gfs2_setbit(&pos, true, GFS2_BLKST_USED);
+		(*n)++;
+		block++;
+	}
+}
+
+/**
+ * rgblk_free - Change alloc state of given block(s)
+ * @sdp: the filesystem
+ * @rgd: the resource group the blocks are in
+ * @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
+ */
+
+static void rgblk_free(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd,
+		       u64 bstart, u32 blen, unsigned char new_state)
+{
+	struct gfs2_rbm rbm;
+	struct gfs2_bitmap *bi, *bi_prev = NULL;
+
+	rbm.rgd = rgd;
+	if (WARN_ON_ONCE(gfs2_rbm_from_block(&rbm, bstart)))
+		return;
+	while (blen--) {
+		bi = rbm_bi(&rbm);
+		if (bi != bi_prev) {
+			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_bytes);
+			}
+			gfs2_trans_add_meta(rbm.rgd->rd_gl, bi->bi_bh);
+			bi_prev = bi;
+		}
+		gfs2_setbit(&rbm, false, new_state);
+		gfs2_rbm_incr(&rbm);
+	}
+}
+
+/**
+ * gfs2_rgrp_dump - print out an rgrp
+ * @seq: The iterator
+ * @rgd: The rgrp in question
+ * @fs_id_buf: pointer to file system id (if requested)
+ *
+ */
+
+void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_rgrpd *rgd,
+		    const char *fs_id_buf)
+{
+	struct gfs2_blkreserv *trs;
+	const struct rb_node *n;
+
+	gfs2_print_dbg(seq, "%s R: n:%llu f:%02x b:%u/%u i:%u r:%u e:%u\n",
+		       fs_id_buf,
+		       (unsigned long long)rgd->rd_addr, rgd->rd_flags,
+		       rgd->rd_free, rgd->rd_free_clone, rgd->rd_dinodes,
+		       rgd->rd_reserved, rgd->rd_extfail_pt);
+	if (rgd->rd_sbd->sd_args.ar_rgrplvb && rgd->rd_rgl) {
+		struct gfs2_rgrp_lvb *rgl = rgd->rd_rgl;
+
+		gfs2_print_dbg(seq, "%s  L: f:%02x b:%u i:%u\n", fs_id_buf,
+			       be32_to_cpu(rgl->rl_flags),
+			       be32_to_cpu(rgl->rl_free),
+			       be32_to_cpu(rgl->rl_dinodes));
+	}
+	spin_lock(&rgd->rd_rsspin);
+	for (n = rb_first(&rgd->rd_rstree); n; n = rb_next(&trs->rs_node)) {
+		trs = rb_entry(n, struct gfs2_blkreserv, rs_node);
+		dump_rs(seq, trs, fs_id_buf);
+	}
+	spin_unlock(&rgd->rd_rsspin);
+}
+
+static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+	char fs_id_buf[sizeof(sdp->sd_fsname) + 7];
+
+	fs_warn(sdp, "rgrp %llu has an error, marking it readonly until umount\n",
+		(unsigned long long)rgd->rd_addr);
+	fs_warn(sdp, "umount on all nodes and run fsck.gfs2 to fix the error\n");
+	sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
+	gfs2_rgrp_dump(NULL, rgd, fs_id_buf);
+	rgd->rd_flags |= GFS2_RDF_ERROR;
+}
+
+/**
+ * gfs2_adjust_reservation - Adjust (or remove) a reservation after allocation
+ * @ip: The inode we have just allocated blocks for
+ * @rbm: The start of the allocated blocks
+ * @len: The extent length
+ *
+ * Adjusts a reservation after an allocation has taken place. If the
+ * reservation does not match the allocation, or if it is now empty
+ * then it is removed.
+ */
+
+static void gfs2_adjust_reservation(struct gfs2_inode *ip,
+				    const struct gfs2_rbm *rbm, unsigned len)
+{
+	struct gfs2_blkreserv *rs = &ip->i_res;
+	struct gfs2_rgrpd *rgd = rbm->rgd;
+	unsigned rlen;
+	u64 block;
+	int ret;
+
+	spin_lock(&rgd->rd_rsspin);
+	if (gfs2_rs_active(rs)) {
+		if (gfs2_rbm_eq(&rs->rs_rbm, rbm)) {
+			block = gfs2_rbm_to_block(rbm);
+			ret = gfs2_rbm_from_block(&rs->rs_rbm, block + len);
+			rlen = min(rs->rs_free, len);
+			rs->rs_free -= rlen;
+			rgd->rd_reserved -= rlen;
+			trace_gfs2_rs(rs, TRACE_RS_CLAIM);
+			if (rs->rs_free && !ret)
+				goto out;
+			/* We used up our block reservation, so we should
+			   reserve more blocks next time. */
+			atomic_add(RGRP_RSRV_ADDBLKS, &ip->i_sizehint);
+		}
+		__rs_deltree(rs);
+	}
+out:
+	spin_unlock(&rgd->rd_rsspin);
+}
+
+/**
+ * gfs2_set_alloc_start - Set starting point for block allocation
+ * @rbm: The rbm which will be set to the required location
+ * @ip: The gfs2 inode
+ * @dinode: Flag to say if allocation includes a new inode
+ *
+ * This sets the starting point from the reservation if one is active
+ * otherwise it falls back to guessing a start point based on the
+ * inode's goal block or the last allocation point in the rgrp.
+ */
+
+static void gfs2_set_alloc_start(struct gfs2_rbm *rbm,
+				 const struct gfs2_inode *ip, bool dinode)
+{
+	u64 goal;
+
+	if (gfs2_rs_active(&ip->i_res)) {
+		*rbm = ip->i_res.rs_rbm;
+		return;
+	}
+
+	if (!dinode && rgrp_contains_block(rbm->rgd, ip->i_goal))
+		goal = ip->i_goal;
+	else
+		goal = rbm->rgd->rd_last_alloc + rbm->rgd->rd_data0;
+
+	if (WARN_ON_ONCE(gfs2_rbm_from_block(rbm, goal))) {
+		rbm->bii = 0;
+		rbm->offset = 0;
+	}
+}
+
+/**
+ * gfs2_alloc_blocks - Allocate one or more blocks of data and/or a dinode
+ * @ip: the inode to allocate the block for
+ * @bn: Used to return the starting block number
+ * @nblocks: requested number of blocks/extent length (value/result)
+ * @dinode: 1 if we're allocating a dinode block, else 0
+ * @generation: the generation number of the inode
+ *
+ * Returns: 0 or error
+ */
+
+int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
+		      bool dinode, u64 *generation)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct buffer_head *dibh;
+	struct gfs2_rbm rbm = { .rgd = ip->i_res.rs_rbm.rgd, };
+	unsigned int ndata;
+	u64 block; /* block, within the file system scope */
+	u32 minext = 1;
+	int error;
+
+	gfs2_set_alloc_start(&rbm, ip, dinode);
+	error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, &minext, ip, false);
+
+	if (error == -ENOSPC) {
+		gfs2_set_alloc_start(&rbm, ip, dinode);
+		error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, &minext, NULL, false);
+	}
+
+	/* Since all blocks are reserved in advance, this shouldn't happen */
+	if (error) {
+		fs_warn(sdp, "inum=%llu error=%d, nblocks=%u, full=%d fail_pt=%d\n",
+			(unsigned long long)ip->i_no_addr, error, *nblocks,
+			test_bit(GBF_FULL, &rbm.rgd->rd_bits->bi_flags),
+			rbm.rgd->rd_extfail_pt);
+		goto rgrp_error;
+	}
+
+	gfs2_alloc_extent(&rbm, dinode, nblocks);
+	block = gfs2_rbm_to_block(&rbm);
+	rbm.rgd->rd_last_alloc = block - rbm.rgd->rd_data0;
+	if (gfs2_rs_active(&ip->i_res))
+		gfs2_adjust_reservation(ip, &rbm, *nblocks);
+	ndata = *nblocks;
+	if (dinode)
+		ndata--;
+
+	if (!dinode) {
+		ip->i_goal = block + ndata - 1;
+		error = gfs2_meta_inode_buffer(ip, &dibh);
+		if (error == 0) {
+			struct gfs2_dinode *di =
+				(struct gfs2_dinode *)dibh->b_data;
+			gfs2_trans_add_meta(ip->i_gl, dibh);
+			di->di_goal_meta = di->di_goal_data =
+				cpu_to_be64(ip->i_goal);
+			brelse(dibh);
+		}
+	}
+	if (rbm.rgd->rd_free < *nblocks) {
+		fs_warn(sdp, "nblocks=%u\n", *nblocks);
+		goto rgrp_error;
+	}
+
+	rbm.rgd->rd_free -= *nblocks;
+	if (dinode) {
+		rbm.rgd->rd_dinodes++;
+		*generation = rbm.rgd->rd_igeneration++;
+		if (*generation == 0)
+			*generation = rbm.rgd->rd_igeneration++;
+	}
+
+	gfs2_trans_add_meta(rbm.rgd->rd_gl, rbm.rgd->rd_bits[0].bi_bh);
+	gfs2_rgrp_out(rbm.rgd, rbm.rgd->rd_bits[0].bi_bh->b_data);
+
+	gfs2_statfs_change(sdp, 0, -(s64)*nblocks, dinode ? 1 : 0);
+	if (dinode)
+		gfs2_trans_remove_revoke(sdp, block, *nblocks);
+
+	gfs2_quota_change(ip, *nblocks, ip->i_inode.i_uid, ip->i_inode.i_gid);
+
+	rbm.rgd->rd_free_clone -= *nblocks;
+	trace_gfs2_block_alloc(ip, rbm.rgd, block, *nblocks,
+			       dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
+	*bn = block;
+	return 0;
+
+rgrp_error:
+	gfs2_rgrp_error(rbm.rgd);
+	return -EIO;
+}
+
+/**
+ * __gfs2_free_blocks - free a contiguous run of block(s)
+ * @ip: the inode these blocks are being freed from
+ * @rgd: the resource group the blocks are in
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ * @meta: 1 if the blocks represent metadata
+ *
+ */
+
+void __gfs2_free_blocks(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
+			u64 bstart, u32 blen, int meta)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+
+	rgblk_free(sdp, rgd, bstart, blen, GFS2_BLKST_FREE);
+	trace_gfs2_block_alloc(ip, rgd, bstart, blen, GFS2_BLKST_FREE);
+	rgd->rd_free += blen;
+	rgd->rd_flags &= ~GFS2_RGF_TRIMMED;
+	gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
+	gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
+
+	/* Directories keep their data in the metadata address space */
+	if (meta || ip->i_depth || gfs2_is_jdata(ip))
+		gfs2_journal_wipe(ip, bstart, blen);
+}
+
+/**
+ * gfs2_free_meta - free a contiguous run of data block(s)
+ * @ip: the inode these blocks are being freed from
+ * @rgd: the resource group the blocks are in
+ * @bstart: first block of a run of contiguous blocks
+ * @blen: the length of the block run
+ *
+ */
+
+void gfs2_free_meta(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
+		    u64 bstart, u32 blen)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+
+	__gfs2_free_blocks(ip, rgd, bstart, blen, 1);
+	gfs2_statfs_change(sdp, 0, +blen, 0);
+	gfs2_quota_change(ip, -(s64)blen, ip->i_inode.i_uid, ip->i_inode.i_gid);
+}
+
+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_no_addr;
+
+	rgd = gfs2_blk2rgrpd(sdp, blkno, true);
+	if (!rgd)
+		return;
+	rgblk_free(sdp, rgd, blkno, 1, GFS2_BLKST_UNLINKED);
+	trace_gfs2_block_alloc(ip, rgd, blkno, 1, GFS2_BLKST_UNLINKED);
+	gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
+	gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
+	be32_add_cpu(&rgd->rd_rgl->rl_unlinked, 1);
+}
+
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = rgd->rd_sbd;
+
+	rgblk_free(sdp, rgd, ip->i_no_addr, 1, GFS2_BLKST_FREE);
+	if (!rgd->rd_dinodes)
+		gfs2_consist_rgrpd(rgd);
+	rgd->rd_dinodes--;
+	rgd->rd_free++;
+
+	gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
+	gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
+	be32_add_cpu(&rgd->rd_rgl->rl_unlinked, -1);
+
+	gfs2_statfs_change(sdp, 0, +1, -1);
+	trace_gfs2_block_alloc(ip, rgd, ip->i_no_addr, 1, GFS2_BLKST_FREE);
+	gfs2_quota_change(ip, -1, ip->i_inode.i_uid, ip->i_inode.i_gid);
+	gfs2_journal_wipe(ip, ip->i_no_addr, 1);
+}
+
+/**
+ * gfs2_check_blk_type - Check the type of a block
+ * @sdp: The superblock
+ * @no_addr: The block number to check
+ * @type: The block type we are looking for
+ *
+ * Returns: 0 if the block type matches the expected type
+ *          -ESTALE if it doesn't match
+ *          or -ve errno if something went wrong while checking
+ */
+
+int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr, unsigned int type)
+{
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_holder rgd_gh;
+	struct gfs2_rbm rbm;
+	int error = -EINVAL;
+
+	rgd = gfs2_blk2rgrpd(sdp, no_addr, 1);
+	if (!rgd)
+		goto fail;
+
+	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
+	if (error)
+		goto fail;
+
+	rbm.rgd = rgd;
+	error = gfs2_rbm_from_block(&rbm, no_addr);
+	if (!WARN_ON_ONCE(error)) {
+		if (gfs2_testbit(&rbm, false) != type)
+			error = -ESTALE;
+	}
+
+	gfs2_glock_dq_uninit(&rgd_gh);
+
+fail:
+	return error;
+}
+
+/**
+ * gfs2_rlist_add - add a RG to a list of RGs
+ * @ip: the inode
+ * @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_inode *ip, struct gfs2_rgrp_list *rlist,
+		    u64 block)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_rgrpd **tmp;
+	unsigned int new_space;
+	unsigned int x;
+
+	if (gfs2_assert_warn(sdp, !rlist->rl_ghs))
+		return;
+
+	/*
+	 * The resource group last accessed is kept in the last position.
+	 */
+
+	if (rlist->rl_rgrps) {
+		rgd = rlist->rl_rgd[rlist->rl_rgrps - 1];
+		if (rgrp_contains_block(rgd, block))
+			return;
+		rgd = gfs2_blk2rgrpd(sdp, block, 1);
+	} else {
+		rgd = ip->i_res.rs_rbm.rgd;
+		if (!rgd || !rgrp_contains_block(rgd, block))
+			rgd = gfs2_blk2rgrpd(sdp, block, 1);
+	}
+
+	if (!rgd) {
+		fs_err(sdp, "rlist_add: no rgrp for block %llu\n",
+		       (unsigned long long)block);
+		return;
+	}
+
+	for (x = 0; x < rlist->rl_rgrps; x++) {
+		if (rlist->rl_rgd[x] == rgd) {
+			swap(rlist->rl_rgd[x],
+			     rlist->rl_rgd[rlist->rl_rgrps - 1]);
+			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
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist)
+{
+	unsigned int x;
+
+	rlist->rl_ghs = kmalloc_array(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,
+				LM_ST_EXCLUSIVE, 0,
+				&rlist->rl_ghs[x]);
+}
+
+/**
+ * gfs2_rlist_free - free a resource group list
+ * @rlist: 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);
+		rlist->rl_ghs = NULL;
+	}
+}
+