Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / gfs2 / rgrp.c
diff --git a/kernel/fs/gfs2/rgrp.c b/kernel/fs/gfs2/rgrp.c
new file mode 100644 (file)
index 0000000..6af2396
--- /dev/null
@@ -0,0 +1,2623 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2008 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 version 2.
+ */
+
+#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"
+
+#define BFITNOENT ((u32)~0)
+#define NO_BLOCK ((u64)~0)
+
+#if BITS_PER_LONG == 32
+#define LBITMASK   (0x55555555UL)
+#define LBITSKIP55 (0x55555555UL)
+#define LBITSKIP00 (0x00000000UL)
+#else
+#define LBITMASK   (0x5555555555555555UL)
+#define LBITSKIP55 (0x5555555555555555UL)
+#define LBITSKIP00 (0x0000000000000000UL)
+#endif
+
+/*
+ * 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,
+                        const struct gfs2_alloc_parms *ap);
+
+
+/**
+ * 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_len;
+       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])) {
+               pr_warn("buf_blk = 0x%x old_state=%d, new_state=%d\n",
+                       rbm->offset, cur_state, new_state);
+               pr_warn("rgrp=0x%llx bi_start=0x%x\n",
+                       (unsigned long long)rbm->rgd->rd_addr, bi->bi_start);
+               pr_warn("bi_offset=0x%x bi_len=0x%x\n",
+                       bi->bi_offset, bi->bi_len);
+               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
+ *
+ * Returns: The two bit block state of the requested bit
+ */
+
+static inline u8 gfs2_testbit(const struct gfs2_rbm *rbm)
+{
+       struct gfs2_bitmap *bi = rbm_bi(rbm);
+       const u8 *buffer = bi->bi_bh->b_data + bi->bi_offset;
+       const u8 *byte;
+       unsigned int bit;
+
+       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)
+{
+       u64 rblock = block - rbm->rgd->rd_data0;
+
+       if (WARN_ON_ONCE(rblock > UINT_MAX))
+               return -EINVAL;
+       if (block >= rbm->rgd->rd_data0 + rbm->rgd->rd_data)
+               return -E2BIG;
+
+       rbm->bii = 0;
+       rbm->offset = (u32)(rblock);
+       /* 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);
+               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;
+               end = start + bi->bi_bh->b_size;
+               start += bi->bi_offset;
+               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_len, x);
+       }
+
+       if (count[0] != rgd->rd_free) {
+               if (gfs2_consist_rgrpd(rgd))
+                       fs_err(sdp, "free data mismatch:  %u != %u\n",
+                              count[0], rgd->rd_free);
+               return;
+       }
+
+       tmp = rgd->rd_data - rgd->rd_free - rgd->rd_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] + count[3] != rgd->rd_dinodes) {
+               if (gfs2_consist_rgrpd(rgd))
+                       fs_err(sdp, "used metadata mismatch:  %u != %u\n",
+                              count[2] + count[3], rgd->rd_dinodes);
+               return;
+       }
+}
+
+static inline int rgrp_contains_block(struct gfs2_rgrpd *rgd, u64 block)
+{
+       u64 first = rgd->rd_data0;
+       u64 last = first + rgd->rd_data;
+       return first <= block && block < last;
+}
+
+/**
+ * gfs2_blk2rgrpd - Find resource group for a given data/meta block number
+ * @sdp: The GFS2 superblock
+ * @blk: The data block number
+ * @exact: True if this needs to be an exact match
+ *
+ * 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;
+       }
+}
+
+/**
+ * gfs2_rs_alloc - make sure we have a reservation assigned to the inode
+ * @ip: the inode for this reservation
+ */
+int gfs2_rs_alloc(struct gfs2_inode *ip)
+{
+       int error = 0;
+
+       down_write(&ip->i_rw_mutex);
+       if (ip->i_res)
+               goto out;
+
+       ip->i_res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
+       if (!ip->i_res) {
+               error = -ENOMEM;
+               goto out;
+       }
+
+       RB_CLEAR_NODE(&ip->i_res->rs_node);
+out:
+       up_write(&ip->i_rw_mutex);
+       return error;
+}
+
+static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)
+{
+       gfs2_print_dbg(seq, "  B: n:%llu s:%llu b:%u f:%u\n",
+                      (unsigned long long)rs->rs_inum,
+                      (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) {
+               struct gfs2_bitmap *bi = rbm_bi(&rs->rs_rbm);
+
+               /* 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;
+               clear_bit(GBF_FULL, &bi->bi_flags);
+       }
+}
+
+/**
+ * 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);
+               spin_unlock(&rgd->rd_rsspin);
+       }
+}
+
+/**
+ * gfs2_rs_delete - delete a multi-block reservation
+ * @ip: The inode for this reservation
+ * @wcount: The inode's write count, or NULL
+ *
+ */
+void gfs2_rs_delete(struct gfs2_inode *ip, atomic_t *wcount)
+{
+       down_write(&ip->i_rw_mutex);
+       if (ip->i_res && ((wcount == NULL) || (atomic_read(wcount) <= 1))) {
+               gfs2_rs_deltree(ip->i_res);
+               BUG_ON(ip->i_res->rs_free);
+               kmem_cache_free(gfs2_rsrv_cachep, ip->i_res);
+               ip->i_res = NULL;
+       }
+       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) {
+                       spin_lock(&gl->gl_spin);
+                       gl->gl_object = NULL;
+                       spin_unlock(&gl->gl_spin);
+                       gfs2_glock_add_to_lru(gl);
+                       gfs2_glock_put(gl);
+               }
+
+               gfs2_free_clones(rgd);
+               kfree(rgd->rd_bits);
+               return_all_reservations(rgd);
+               kmem_cache_free(gfs2_rgrpd_cachep, rgd);
+       }
+}
+
+static void gfs2_rindex_print(const struct gfs2_rgrpd *rgd)
+{
+       pr_info("ri_addr = %llu\n", (unsigned long long)rgd->rd_addr);
+       pr_info("ri_length = %u\n", rgd->rd_length);
+       pr_info("ri_data0 = %llu\n", (unsigned long long)rgd->rd_data0);
+       pr_info("ri_data = %u\n", rgd->rd_data);
+       pr_info("ri_bitbytes = %u\n", rgd->rd_bitbytes);
+}
+
+/**
+ * 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_len = 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_len = 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_len = 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_len = 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_len) * GFS2_NBBY != rgd->rd_data) {
+               if (gfs2_consist_rgrpd(rgd)) {
+                       gfs2_rindex_print(rgd);
+                       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_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);
+       const unsigned bsize = sdp->sd_sb.sb_bsize;
+       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 = compute_bitstructs(rgd);
+       if (error)
+               goto fail;
+
+       error = gfs2_glock_get(sdp, rgd->rd_addr,
+                              &gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
+       if (error)
+               goto fail;
+
+       rgd->rd_gl->gl_object = rgd;
+       rgd->rd_gl->gl_vm.start = rgd->rd_addr * bsize;
+       rgd->rd_gl->gl_vm.end = rgd->rd_gl->gl_vm.start + (rgd->rd_length * bsize) - 1;
+       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)
+               return 0;
+
+       error = 0; /* someone else read in the rgrp; free it and ignore it */
+       gfs2_glock_put(rgd->rd_gl);
+
+fail:
+       kfree(rgd->rd_bits);
+       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 == first)
+                               break;
+               }
+       } while (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;
+
+       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);
+}
+
+static void gfs2_rgrp_out(struct gfs2_rgrpd *rgd, void *buf)
+{
+       struct gfs2_rgrp *str = buf;
+
+       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);
+       str->__pad = cpu_to_be32(0);
+       str->rg_igeneration = cpu_to_be64(rgd->rd_igeneration);
+       memset(&str->rg_reserved, 0, sizeof(str->rg_reserved));
+}
+
+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;
+
+       if (rgl->rl_flags != str->rg_flags || rgl->rl_free != str->rg_free ||
+           rgl->rl_dinodes != str->rg_dinodes ||
+           rgl->rl_igeneration != str->rg_igeneration)
+               return 0;
+       return 1;
+}
+
+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 update_rgrp_lvb_unlinked(struct gfs2_rgrpd *rgd, u32 change)
+{
+       struct gfs2_rgrp_lvb *rgl = rgd->rd_rgl;
+       u32 unlinked = be32_to_cpu(rgl->rl_unlinked) + change;
+       rgl->rl_unlinked = cpu_to_be32(unlinked);
+}
+
+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_len * GFS2_NBBY) {
+                       goal = gfs2_bitfit(buffer, bi->bi_len, 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_relse() 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, &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_UPTODATE | 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;
+       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_go_unlock - Release RG bitmaps read in with gfs2_rgrp_bh_get()
+ * @gh: The glock holder for the resource group
+ *
+ */
+
+void gfs2_rgrp_go_unlock(struct gfs2_holder *gh)
+{
+       struct gfs2_rgrpd *rgd = gh->gh_gl->gl_object;
+       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_len; 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", 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 (!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,
+                      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_rgrp_ondisk2lvb(rgd->rd_rgl, 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);
+}
+
+/**
+ * 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->rd_free_clone - rgd->rd_reserved;
+       int ret;
+       struct inode *inode = &ip->i_inode;
+
+       if (S_ISDIR(inode->i_mode))
+               extlen = 1;
+       else {
+               extlen = max_t(u32, atomic_read(&rs->rs_sizehint), ap->target);
+               extlen = clamp(extlen, 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, ap);
+       if (ret == 0) {
+               rs->rs_rbm = rbm;
+               rs->rs_free = extlen;
+               rs->rs_inum = ip->i_no_addr;
+               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) {
+               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 (NULL for a single block)
+ *          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.
+ * @ap: the allocation parameters
+ *
+ * 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,
+                        const struct gfs2_alloc_parms *ap)
+{
+       struct buffer_head *bh;
+       int initial_bii;
+       u32 initial_offset;
+       int first_bii = rbm->bii;
+       u32 first_offset = rbm->offset;
+       u32 offset;
+       u8 *buffer;
+       int n = 0;
+       int iters = rbm->rgd->rd_length;
+       int ret;
+       struct gfs2_bitmap *bi;
+       struct gfs2_extent maxext = { .rbm.rgd = rbm->rgd, };
+
+       /* If we are not starting at the beginning of a bitmap, then we
+        * need to add one to the bitmap count to ensure that we search
+        * the starting bitmap twice.
+        */
+       if (rbm->offset != 0)
+               iters++;
+
+       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;
+               initial_offset = rbm->offset;
+               offset = gfs2_bitfit(buffer, bi->bi_len, rbm->offset, state);
+               if (offset == BFITNOENT)
+                       goto bitmap_full;
+               rbm->offset = offset;
+               if (ip == NULL)
+                       return 0;
+
+               initial_bii = rbm->bii;
+               ret = gfs2_reservation_check_and_update(rbm, ip,
+                                                       minext ? *minext : 0,
+                                                       &maxext);
+               if (ret == 0)
+                       return 0;
+               if (ret > 0) {
+                       n += (rbm->bii - initial_bii);
+                       goto next_iter;
+               }
+               if (ret == -E2BIG) {
+                       rbm->bii = 0;
+                       rbm->offset = 0;
+                       n += (rbm->bii - initial_bii);
+                       goto res_covered_end_of_rgrp;
+               }
+               return ret;
+
+bitmap_full:   /* Mark bitmap as full and fall through */
+               if ((state == GFS2_BLKST_FREE) && initial_offset == 0) {
+                       struct gfs2_bitmap *bi = rbm_bi(rbm);
+                       set_bit(GBF_FULL, &bi->bi_flags);
+               }
+
+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) && nowrap)
+                       break;
+               n++;
+next_iter:
+               if (n >= iters)
+                       break;
+       }
+
+       if (minext == NULL || 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 ((first_offset == 0) && (first_bii == 0) &&
+           (*minext < rbm->rgd->rd_extfail_pt))
+               rbm->rgd->rd_extfail_pt = *minext;
+
+       /* 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) {
+               down_write(&sdp->sd_log_flush_lock);
+               error = gfs2_rbm_find(&rbm, GFS2_BLKST_UNLINKED, NULL, NULL,
+                                     true, NULL);
+               up_write(&sdp->sd_log_flush_lock);
+               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_inode_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 || queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 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_sbd;
+       struct gfs2_lkstats *st;
+       s64 r_dcount, l_dcount;
+       s64 r_srttb, l_srttb;
+       s64 srttb_diff;
+       s64 sqr_diff;
+       s64 var;
+
+       preempt_disable();
+       st = &this_cpu_ptr(sdp->sd_lkstats)->lkstats[LM_TYPE_RGRP];
+       r_srttb = st->stats[GFS2_LKS_SRTTB];
+       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) || (r_srttb == 0))
+               return false;
+
+       srttb_diff = r_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
+ * atleast 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 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 (ip->i_rgd && rgrp_contains_block(ip->i_rgd, ip->i_goal)) {
+               rs->rs_rbm.rgd = begin = ip->i_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,
+                                                  &rs->rs_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(&rs->rs_rgd_gh);
+                                       return error;
+                               }
+                       }
+               }
+
+               /* Skip unuseable 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 */
+               if (rs->rs_rbm.rgd->rd_free_clone >= ap->target ||
+                   (loops == 2 && ap->min_target &&
+                    rs->rs_rbm.rgd->rd_free_clone >= ap->min_target)) {
+                       ip->i_rgd = rs->rs_rbm.rgd;
+                       ap->allowed = ip->i_rgd->rd_free_clone;
+                       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(&rs->rs_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, NORMAL_FLUSH);
+       }
+
+       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)
+{
+       struct gfs2_blkreserv *rs = ip->i_res;
+
+       if (rs->rs_rgd_gh.gh_gl)
+               gfs2_glock_dq_uninit(&rs->rs_rgd_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_*)
+ */
+
+static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block)
+{
+       struct gfs2_rbm rbm = { .rgd = rgd, };
+       int ret;
+
+       ret = gfs2_rbm_from_block(&rbm, block);
+       WARN_ON_ONCE(ret != 0);
+
+       return gfs2_testbit(&rbm);
+}
+
+
+/**
+ * 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) != 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
+ * @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, u64 bstart,
+                                    u32 blen, unsigned char new_state)
+{
+       struct gfs2_rbm rbm;
+       struct gfs2_bitmap *bi, *bi_prev = NULL;
+
+       rbm.rgd = gfs2_blk2rgrpd(sdp, bstart, 1);
+       if (!rbm.rgd) {
+               if (gfs2_consist(sdp))
+                       fs_err(sdp, "block = %llu\n", (unsigned long long)bstart);
+               return NULL;
+       }
+
+       gfs2_rbm_from_block(&rbm, bstart);
+       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_len);
+                       }
+                       gfs2_trans_add_meta(rbm.rgd->rd_gl, bi->bi_bh);
+                       bi_prev = bi;
+               }
+               gfs2_setbit(&rbm, false, new_state);
+               gfs2_rbm_incr(&rbm);
+       }
+
+       return rbm.rgd;
+}
+
+/**
+ * gfs2_rgrp_dump - print out an rgrp
+ * @seq: The iterator
+ * @gl: The glock in question
+ *
+ */
+
+void gfs2_rgrp_dump(struct seq_file *seq, const struct gfs2_glock *gl)
+{
+       struct gfs2_rgrpd *rgd = gl->gl_object;
+       struct gfs2_blkreserv *trs;
+       const struct rb_node *n;
+
+       if (rgd == NULL)
+               return;
+       gfs2_print_dbg(seq, " R: n:%llu f:%02x b:%u/%u i:%u r:%u e:%u\n",
+                      (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);
+       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);
+       }
+       spin_unlock(&rgd->rd_rsspin);
+}
+
+static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd)
+{
+       struct gfs2_sbd *sdp = rgd->rd_sbd;
+       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");
+       gfs2_rgrp_dump(NULL, rgd->rd_gl);
+       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, &rs->rs_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;
+
+       gfs2_rbm_from_block(rbm, goal);
+}
+
+/**
+ * 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_rgd, };
+       unsigned int ndata;
+       u64 block; /* block, within the file system scope */
+       int error;
+
+       gfs2_set_alloc_start(&rbm, ip, dinode);
+       error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, NULL, ip, false, NULL);
+
+       if (error == -ENOSPC) {
+               gfs2_set_alloc_start(&rbm, ip, dinode);
+               error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, NULL, NULL, false,
+                                     NULL);
+       }
+
+       /* 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) {
+               pr_warn("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_rgrp_ondisk2lvb(rbm.rgd->rd_rgl, rbm.rgd->rd_bits[0].bi_bh->b_data);
+
+       gfs2_statfs_change(sdp, 0, -(s64)*nblocks, dinode ? 1 : 0);
+       if (dinode)
+               gfs2_trans_add_unrevoke(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
+ * @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, u64 bstart, u32 blen, int meta)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+       struct gfs2_rgrpd *rgd;
+
+       rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
+       if (!rgd)
+               return;
+       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);
+       gfs2_rgrp_ondisk2lvb(rgd->rd_rgl, rgd->rd_bits[0].bi_bh->b_data);
+
+       /* Directories keep their data in the metadata address space */
+       if (meta || ip->i_depth)
+               gfs2_meta_wipe(ip, bstart, blen);
+}
+
+/**
+ * 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, u64 bstart, u32 blen)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+
+       __gfs2_free_blocks(ip, 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 = rgblk_free(sdp, blkno, 1, GFS2_BLKST_UNLINKED);
+       if (!rgd)
+               return;
+       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);
+       gfs2_rgrp_ondisk2lvb(rgd->rd_rgl, rgd->rd_bits[0].bi_bh->b_data);
+       update_rgrp_lvb_unlinked(rgd, 1);
+}
+
+static void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, u64 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_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);
+       gfs2_rgrp_ondisk2lvb(rgd->rd_rgl, rgd->rd_bits[0].bi_bh->b_data);
+       update_rgrp_lvb_unlinked(rgd, -1);
+
+       gfs2_statfs_change(sdp, 0, +1, -1);
+}
+
+
+void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
+{
+       gfs2_free_uninit_di(rgd, ip->i_no_addr);
+       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_meta_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;
+       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;
+
+       if (gfs2_get_block_type(rgd, no_addr) != 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;
+
+       if (ip->i_rgd && rgrp_contains_block(ip->i_rgd, block))
+               rgd = ip->i_rgd;
+       else
+               rgd = gfs2_blk2rgrpd(sdp, block, 1);
+       if (!rgd) {
+               fs_err(sdp, "rlist_add: no rgrp for block %llu\n", (unsigned long long)block);
+               return;
+       }
+       ip->i_rgd = rgd;
+
+       for (x = 0; x < rlist->rl_rgrps; x++)
+               if (rlist->rl_rgd[x] == rgd)
+                       return;
+
+       if (rlist->rl_rgrps == rlist->rl_space) {
+               new_space = rlist->rl_space + 10;
+
+               tmp = kcalloc(new_space, sizeof(struct gfs2_rgrpd *),
+                             GFP_NOFS | __GFP_NOFAIL);
+
+               if (rlist->rl_rgd) {
+                       memcpy(tmp, rlist->rl_rgd,
+                              rlist->rl_space * sizeof(struct gfs2_rgrpd *));
+                       kfree(rlist->rl_rgd);
+               }
+
+               rlist->rl_space = new_space;
+               rlist->rl_rgd = tmp;
+       }
+
+       rlist->rl_rgd[rlist->rl_rgrps++] = rgd;
+}
+
+/**
+ * gfs2_rlist_alloc - all RGs have been added to the rlist, now allocate
+ *      and initialize an array of glock holders for them
+ * @rlist: the list of resource groups
+ * @state: the lock state to acquire the RG lock in
+ *
+ * FIXME: Don't use NOFAIL
+ *
+ */
+
+void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state)
+{
+       unsigned int x;
+
+       rlist->rl_ghs = kcalloc(rlist->rl_rgrps, sizeof(struct gfs2_holder),
+                               GFP_NOFS | __GFP_NOFAIL);
+       for (x = 0; x < rlist->rl_rgrps; x++)
+               gfs2_holder_init(rlist->rl_rgd[x]->rd_gl,
+                               state, 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;
+       }
+}
+