Initial import

1 files changed, 2090 insertions, 0 deletions

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
new file mode 100644
index 000000000..487527b42
--- /dev/null
+++ b/fs/gfs2/dir.c
@@ -0,0 +1,2090 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+/*
+ * Implements Extendible Hashing as described in:
+ *   "Extendible Hashing" by Fagin, et al in
+ *     __ACM Trans. on Database Systems__, Sept 1979.
+ *
+ *
+ * Here's the layout of dirents which is essentially the same as that of ext2
+ * within a single block. The field de_name_len is the number of bytes
+ * actually required for the name (no null terminator). The field de_rec_len
+ * is the number of bytes allocated to the dirent. The offset of the next
+ * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
+ * deleted, the preceding dirent inherits its allocated space, ie
+ * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
+ * by adding de_rec_len to the current dirent, this essentially causes the
+ * deleted dirent to get jumped over when iterating through all the dirents.
+ *
+ * When deleting the first dirent in a block, there is no previous dirent so
+ * the field de_ino is set to zero to designate it as deleted. When allocating
+ * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
+ * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
+ * dirent is allocated. Otherwise it must go through all the 'used' dirents
+ * searching for one in which the amount of total space minus the amount of
+ * used space will provide enough space for the new dirent.
+ *
+ * There are two types of blocks in which dirents reside. In a stuffed dinode,
+ * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
+ * the block.  In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
+ * beginning of the leaf block. The dirents reside in leaves when
+ *
+ * dip->i_diskflags & GFS2_DIF_EXHASH is true
+ *
+ * Otherwise, the dirents are "linear", within a single stuffed dinode block.
+ *
+ * When the dirents are in leaves, the actual contents of the directory file are
+ * used as an array of 64-bit block pointers pointing to the leaf blocks. The
+ * dirents are NOT in the directory file itself. There can be more than one
+ * block pointer in the array that points to the same leaf. In fact, when a
+ * directory is first converted from linear to exhash, all of the pointers
+ * point to the same leaf.
+ *
+ * When a leaf is completely full, the size of the hash table can be
+ * doubled unless it is already at the maximum size which is hard coded into
+ * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
+ * but never before the maximum hash table size has been reached.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/buffer_head.h>
+#include <linux/sort.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/crc32.h>
+#include <linux/vmalloc.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "dir.h"
+#include "glock.h"
+#include "inode.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "bmap.h"
+#include "util.h"
+
+#define IS_LEAF     1 /* Hashed (leaf) directory */
+#define IS_DINODE   2 /* Linear (stuffed dinode block) directory */
+
+#define MAX_RA_BLOCKS 32 /* max read-ahead blocks */
+
+#define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
+#define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
+
+struct qstr gfs2_qdot __read_mostly;
+struct qstr gfs2_qdotdot __read_mostly;
+
+typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
+			    const struct qstr *name, void *opaque);
+
+int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
+			    struct buffer_head **bhp)
+{
+	struct buffer_head *bh;
+
+	bh = gfs2_meta_new(ip->i_gl, block);
+	gfs2_trans_add_meta(ip->i_gl, bh);
+	gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
+	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
+	*bhp = bh;
+	return 0;
+}
+
+static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
+					struct buffer_head **bhp)
+{
+	struct buffer_head *bh;
+	int error;
+
+	error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, &bh);
+	if (error)
+		return error;
+	if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
+		brelse(bh);
+		return -EIO;
+	}
+	*bhp = bh;
+	return 0;
+}
+
+static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
+				  unsigned int offset, unsigned int size)
+{
+	struct buffer_head *dibh;
+	int error;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	gfs2_trans_add_meta(ip->i_gl, dibh);
+	memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
+	if (ip->i_inode.i_size < offset + size)
+		i_size_write(&ip->i_inode, offset + size);
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
+	gfs2_dinode_out(ip, dibh->b_data);
+
+	brelse(dibh);
+
+	return size;
+}
+
+
+
+/**
+ * gfs2_dir_write_data - Write directory information to the inode
+ * @ip: The GFS2 inode
+ * @buf: The buffer containing information to be written
+ * @offset: The file offset to start writing at
+ * @size: The amount of data to write
+ *
+ * Returns: The number of bytes correctly written or error code
+ */
+static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
+			       u64 offset, unsigned int size)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct buffer_head *dibh;
+	u64 lblock, dblock;
+	u32 extlen = 0;
+	unsigned int o;
+	int copied = 0;
+	int error = 0;
+	int new = 0;
+
+	if (!size)
+		return 0;
+
+	if (gfs2_is_stuffed(ip) &&
+	    offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
+		return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
+					      size);
+
+	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+		return -EINVAL;
+
+	if (gfs2_is_stuffed(ip)) {
+		error = gfs2_unstuff_dinode(ip, NULL);
+		if (error)
+			return error;
+	}
+
+	lblock = offset;
+	o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
+
+	while (copied < size) {
+		unsigned int amount;
+		struct buffer_head *bh;
+
+		amount = size - copied;
+		if (amount > sdp->sd_sb.sb_bsize - o)
+			amount = sdp->sd_sb.sb_bsize - o;
+
+		if (!extlen) {
+			new = 1;
+			error = gfs2_extent_map(&ip->i_inode, lblock, &new,
+						&dblock, &extlen);
+			if (error)
+				goto fail;
+			error = -EIO;
+			if (gfs2_assert_withdraw(sdp, dblock))
+				goto fail;
+		}
+
+		if (amount == sdp->sd_jbsize || new)
+			error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
+		else
+			error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
+
+		if (error)
+			goto fail;
+
+		gfs2_trans_add_meta(ip->i_gl, bh);
+		memcpy(bh->b_data + o, buf, amount);
+		brelse(bh);
+
+		buf += amount;
+		copied += amount;
+		lblock++;
+		dblock++;
+		extlen--;
+
+		o = sizeof(struct gfs2_meta_header);
+	}
+
+out:
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	if (ip->i_inode.i_size < offset + copied)
+		i_size_write(&ip->i_inode, offset + copied);
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
+
+	gfs2_trans_add_meta(ip->i_gl, dibh);
+	gfs2_dinode_out(ip, dibh->b_data);
+	brelse(dibh);
+
+	return copied;
+fail:
+	if (copied)
+		goto out;
+	return error;
+}
+
+static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
+				 unsigned int size)
+{
+	struct buffer_head *dibh;
+	int error;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (!error) {
+		memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
+		brelse(dibh);
+	}
+
+	return (error) ? error : size;
+}
+
+
+/**
+ * gfs2_dir_read_data - Read a data from a directory inode
+ * @ip: The GFS2 Inode
+ * @buf: The buffer to place result into
+ * @size: Amount of data to transfer
+ *
+ * Returns: The amount of data actually copied or the error
+ */
+static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
+			      unsigned int size)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	u64 lblock, dblock;
+	u32 extlen = 0;
+	unsigned int o;
+	int copied = 0;
+	int error = 0;
+
+	if (gfs2_is_stuffed(ip))
+		return gfs2_dir_read_stuffed(ip, buf, size);
+
+	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+		return -EINVAL;
+
+	lblock = 0;
+	o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
+
+	while (copied < size) {
+		unsigned int amount;
+		struct buffer_head *bh;
+		int new;
+
+		amount = size - copied;
+		if (amount > sdp->sd_sb.sb_bsize - o)
+			amount = sdp->sd_sb.sb_bsize - o;
+
+		if (!extlen) {
+			new = 0;
+			error = gfs2_extent_map(&ip->i_inode, lblock, &new,
+						&dblock, &extlen);
+			if (error || !dblock)
+				goto fail;
+			BUG_ON(extlen < 1);
+			bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
+		} else {
+			error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
+			if (error)
+				goto fail;
+		}
+		error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
+		if (error) {
+			brelse(bh);
+			goto fail;
+		}
+		dblock++;
+		extlen--;
+		memcpy(buf, bh->b_data + o, amount);
+		brelse(bh);
+		buf += (amount/sizeof(__be64));
+		copied += amount;
+		lblock++;
+		o = sizeof(struct gfs2_meta_header);
+	}
+
+	return copied;
+fail:
+	return (copied) ? copied : error;
+}
+
+/**
+ * gfs2_dir_get_hash_table - Get pointer to the dir hash table
+ * @ip: The inode in question
+ *
+ * Returns: The hash table or an error
+ */
+
+static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
+{
+	struct inode *inode = &ip->i_inode;
+	int ret;
+	u32 hsize;
+	__be64 *hc;
+
+	BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
+
+	hc = ip->i_hash_cache;
+	if (hc)
+		return hc;
+
+	hsize = 1 << ip->i_depth;
+	hsize *= sizeof(__be64);
+	if (hsize != i_size_read(&ip->i_inode)) {
+		gfs2_consist_inode(ip);
+		return ERR_PTR(-EIO);
+	}
+
+	hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
+	if (hc == NULL)
+		hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
+
+	if (hc == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	ret = gfs2_dir_read_data(ip, hc, hsize);
+	if (ret < 0) {
+		kvfree(hc);
+		return ERR_PTR(ret);
+	}
+
+	spin_lock(&inode->i_lock);
+	if (likely(!ip->i_hash_cache)) {
+		ip->i_hash_cache = hc;
+		hc = NULL;
+	}
+	spin_unlock(&inode->i_lock);
+	kvfree(hc);
+
+	return ip->i_hash_cache;
+}
+
+/**
+ * gfs2_dir_hash_inval - Invalidate dir hash
+ * @ip: The directory inode
+ *
+ * Must be called with an exclusive glock, or during glock invalidation.
+ */
+void gfs2_dir_hash_inval(struct gfs2_inode *ip)
+{
+	__be64 *hc = ip->i_hash_cache;
+	ip->i_hash_cache = NULL;
+	kvfree(hc);
+}
+
+static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
+{
+	return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
+}
+
+static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
+				     const struct qstr *name, int ret)
+{
+	if (!gfs2_dirent_sentinel(dent) &&
+	    be32_to_cpu(dent->de_hash) == name->hash &&
+	    be16_to_cpu(dent->de_name_len) == name->len &&
+	    memcmp(dent+1, name->name, name->len) == 0)
+		return ret;
+	return 0;
+}
+
+static int gfs2_dirent_find(const struct gfs2_dirent *dent,
+			    const struct qstr *name,
+			    void *opaque)
+{
+	return __gfs2_dirent_find(dent, name, 1);
+}
+
+static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
+			    const struct qstr *name,
+			    void *opaque)
+{
+	return __gfs2_dirent_find(dent, name, 2);
+}
+
+/*
+ * name->name holds ptr to start of block.
+ * name->len holds size of block.
+ */
+static int gfs2_dirent_last(const struct gfs2_dirent *dent,
+			    const struct qstr *name,
+			    void *opaque)
+{
+	const char *start = name->name;
+	const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
+	if (name->len == (end - start))
+		return 1;
+	return 0;
+}
+
+static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
+				  const struct qstr *name,
+				  void *opaque)
+{
+	unsigned required = GFS2_DIRENT_SIZE(name->len);
+	unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
+	unsigned totlen = be16_to_cpu(dent->de_rec_len);
+
+	if (gfs2_dirent_sentinel(dent))
+		actual = 0;
+	if (totlen - actual >= required)
+		return 1;
+	return 0;
+}
+
+struct dirent_gather {
+	const struct gfs2_dirent **pdent;
+	unsigned offset;
+};
+
+static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
+			      const struct qstr *name,
+			      void *opaque)
+{
+	struct dirent_gather *g = opaque;
+	if (!gfs2_dirent_sentinel(dent)) {
+		g->pdent[g->offset++] = dent;
+	}
+	return 0;
+}
+
+/*
+ * Other possible things to check:
+ * - Inode located within filesystem size (and on valid block)
+ * - Valid directory entry type
+ * Not sure how heavy-weight we want to make this... could also check
+ * hash is correct for example, but that would take a lot of extra time.
+ * For now the most important thing is to check that the various sizes
+ * are correct.
+ */
+static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
+			     unsigned int size, unsigned int len, int first)
+{
+	const char *msg = "gfs2_dirent too small";
+	if (unlikely(size < sizeof(struct gfs2_dirent)))
+		goto error;
+	msg = "gfs2_dirent misaligned";
+	if (unlikely(offset & 0x7))
+		goto error;
+	msg = "gfs2_dirent points beyond end of block";
+	if (unlikely(offset + size > len))
+		goto error;
+	msg = "zero inode number";
+	if (unlikely(!first && gfs2_dirent_sentinel(dent)))
+		goto error;
+	msg = "name length is greater than space in dirent";
+	if (!gfs2_dirent_sentinel(dent) &&
+	    unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
+		     size))
+		goto error;
+	return 0;
+error:
+	pr_warn("%s: %s (%s)\n",
+		__func__, msg, first ? "first in block" : "not first in block");
+	return -EIO;
+}
+
+static int gfs2_dirent_offset(const void *buf)
+{
+	const struct gfs2_meta_header *h = buf;
+	int offset;
+
+	BUG_ON(buf == NULL);
+
+	switch(be32_to_cpu(h->mh_type)) {
+	case GFS2_METATYPE_LF:
+		offset = sizeof(struct gfs2_leaf);
+		break;
+	case GFS2_METATYPE_DI:
+		offset = sizeof(struct gfs2_dinode);
+		break;
+	default:
+		goto wrong_type;
+	}
+	return offset;
+wrong_type:
+	pr_warn("%s: wrong block type %u\n", __func__, be32_to_cpu(h->mh_type));
+	return -1;
+}
+
+static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
+					    unsigned int len, gfs2_dscan_t scan,
+					    const struct qstr *name,
+					    void *opaque)
+{
+	struct gfs2_dirent *dent, *prev;
+	unsigned offset;
+	unsigned size;
+	int ret = 0;
+
+	ret = gfs2_dirent_offset(buf);
+	if (ret < 0)
+		goto consist_inode;
+
+	offset = ret;
+	prev = NULL;
+	dent = buf + offset;
+	size = be16_to_cpu(dent->de_rec_len);
+	if (gfs2_check_dirent(dent, offset, size, len, 1))
+		goto consist_inode;
+	do {
+		ret = scan(dent, name, opaque);
+		if (ret)
+			break;
+		offset += size;
+		if (offset == len)
+			break;
+		prev = dent;
+		dent = buf + offset;
+		size = be16_to_cpu(dent->de_rec_len);
+		if (gfs2_check_dirent(dent, offset, size, len, 0))
+			goto consist_inode;
+	} while(1);
+
+	switch(ret) {
+	case 0:
+		return NULL;
+	case 1:
+		return dent;
+	case 2:
+		return prev ? prev : dent;
+	default:
+		BUG_ON(ret > 0);
+		return ERR_PTR(ret);
+	}
+
+consist_inode:
+	gfs2_consist_inode(GFS2_I(inode));
+	return ERR_PTR(-EIO);
+}
+
+static int dirent_check_reclen(struct gfs2_inode *dip,
+			       const struct gfs2_dirent *d, const void *end_p)
+{
+	const void *ptr = d;
+	u16 rec_len = be16_to_cpu(d->de_rec_len);
+
+	if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
+		goto broken;
+	ptr += rec_len;
+	if (ptr < end_p)
+		return rec_len;
+	if (ptr == end_p)
+		return -ENOENT;
+broken:
+	gfs2_consist_inode(dip);
+	return -EIO;
+}
+
+/**
+ * dirent_next - Next dirent
+ * @dip: the directory
+ * @bh: The buffer
+ * @dent: Pointer to list of dirents
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
+		       struct gfs2_dirent **dent)
+{
+	struct gfs2_dirent *cur = *dent, *tmp;
+	char *bh_end = bh->b_data + bh->b_size;
+	int ret;
+
+	ret = dirent_check_reclen(dip, cur, bh_end);
+	if (ret < 0)
+		return ret;
+
+	tmp = (void *)cur + ret;
+	ret = dirent_check_reclen(dip, tmp, bh_end);
+	if (ret == -EIO)
+		return ret;
+
+        /* Only the first dent could ever have de_inum.no_addr == 0 */
+	if (gfs2_dirent_sentinel(tmp)) {
+		gfs2_consist_inode(dip);
+		return -EIO;
+	}
+
+	*dent = tmp;
+	return 0;
+}
+
+/**
+ * dirent_del - Delete a dirent
+ * @dip: The GFS2 inode
+ * @bh: The buffer
+ * @prev: The previous dirent
+ * @cur: The current dirent
+ *
+ */
+
+static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
+		       struct gfs2_dirent *prev, struct gfs2_dirent *cur)
+{
+	u16 cur_rec_len, prev_rec_len;
+
+	if (gfs2_dirent_sentinel(cur)) {
+		gfs2_consist_inode(dip);
+		return;
+	}
+
+	gfs2_trans_add_meta(dip->i_gl, bh);
+
+	/* If there is no prev entry, this is the first entry in the block.
+	   The de_rec_len is already as big as it needs to be.  Just zero
+	   out the inode number and return.  */
+
+	if (!prev) {
+		cur->de_inum.no_addr = 0;
+		cur->de_inum.no_formal_ino = 0;
+		return;
+	}
+
+	/*  Combine this dentry with the previous one.  */
+
+	prev_rec_len = be16_to_cpu(prev->de_rec_len);
+	cur_rec_len = be16_to_cpu(cur->de_rec_len);
+
+	if ((char *)prev + prev_rec_len != (char *)cur)
+		gfs2_consist_inode(dip);
+	if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
+		gfs2_consist_inode(dip);
+
+	prev_rec_len += cur_rec_len;
+	prev->de_rec_len = cpu_to_be16(prev_rec_len);
+}
+
+/*
+ * Takes a dent from which to grab space as an argument. Returns the
+ * newly created dent.
+ */
+static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
+					    struct gfs2_dirent *dent,
+					    const struct qstr *name,
+					    struct buffer_head *bh)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_dirent *ndent;
+	unsigned offset = 0, totlen;
+
+	if (!gfs2_dirent_sentinel(dent))
+		offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
+	totlen = be16_to_cpu(dent->de_rec_len);
+	BUG_ON(offset + name->len > totlen);
+	gfs2_trans_add_meta(ip->i_gl, bh);
+	ndent = (struct gfs2_dirent *)((char *)dent + offset);
+	dent->de_rec_len = cpu_to_be16(offset);
+	gfs2_qstr2dirent(name, totlen - offset, ndent);
+	return ndent;
+}
+
+static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
+					     struct buffer_head *bh,
+					     const struct qstr *name)
+{
+	struct gfs2_dirent *dent;
+	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+				gfs2_dirent_find_space, name, NULL);
+	if (!dent || IS_ERR(dent))
+		return dent;
+	return gfs2_init_dirent(inode, dent, name, bh);
+}
+
+static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
+		    struct buffer_head **bhp)
+{
+	int error;
+
+	error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
+	if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
+		/* pr_info("block num=%llu\n", leaf_no); */
+		error = -EIO;
+	}
+
+	return error;
+}
+
+/**
+ * get_leaf_nr - Get a leaf number associated with the index
+ * @dip: The GFS2 inode
+ * @index:
+ * @leaf_out:
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
+		       u64 *leaf_out)
+{
+	__be64 *hash;
+
+	hash = gfs2_dir_get_hash_table(dip);
+	if (IS_ERR(hash))
+		return PTR_ERR(hash);
+	*leaf_out = be64_to_cpu(*(hash + index));
+	return 0;
+}
+
+static int get_first_leaf(struct gfs2_inode *dip, u32 index,
+			  struct buffer_head **bh_out)
+{
+	u64 leaf_no;
+	int error;
+
+	error = get_leaf_nr(dip, index, &leaf_no);
+	if (!error)
+		error = get_leaf(dip, leaf_no, bh_out);
+
+	return error;
+}
+
+static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
+					      const struct qstr *name,
+					      gfs2_dscan_t scan,
+					      struct buffer_head **pbh)
+{
+	struct buffer_head *bh;
+	struct gfs2_dirent *dent;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	int error;
+
+	if (ip->i_diskflags & GFS2_DIF_EXHASH) {
+		struct gfs2_leaf *leaf;
+		unsigned hsize = 1 << ip->i_depth;
+		unsigned index;
+		u64 ln;
+		if (hsize * sizeof(u64) != i_size_read(inode)) {
+			gfs2_consist_inode(ip);
+			return ERR_PTR(-EIO);
+		}
+
+		index = name->hash >> (32 - ip->i_depth);
+		error = get_first_leaf(ip, index, &bh);
+		if (error)
+			return ERR_PTR(error);
+		do {
+			dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+						scan, name, NULL);
+			if (dent)
+				goto got_dent;
+			leaf = (struct gfs2_leaf *)bh->b_data;
+			ln = be64_to_cpu(leaf->lf_next);
+			brelse(bh);
+			if (!ln)
+				break;
+
+			error = get_leaf(ip, ln, &bh);
+		} while(!error);
+
+		return error ? ERR_PTR(error) : NULL;
+	}
+
+
+	error = gfs2_meta_inode_buffer(ip, &bh);
+	if (error)
+		return ERR_PTR(error);
+	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
+got_dent:
+	if (unlikely(dent == NULL || IS_ERR(dent))) {
+		brelse(bh);
+		bh = NULL;
+	}
+	*pbh = bh;
+	return dent;
+}
+
+static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	unsigned int n = 1;
+	u64 bn;
+	int error;
+	struct buffer_head *bh;
+	struct gfs2_leaf *leaf;
+	struct gfs2_dirent *dent;
+	struct qstr name = { .name = "" };
+	struct timespec tv = CURRENT_TIME;
+
+	error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
+	if (error)
+		return NULL;
+	bh = gfs2_meta_new(ip->i_gl, bn);
+	if (!bh)
+		return NULL;
+
+	gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
+	gfs2_trans_add_meta(ip->i_gl, bh);
+	gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
+	leaf = (struct gfs2_leaf *)bh->b_data;
+	leaf->lf_depth = cpu_to_be16(depth);
+	leaf->lf_entries = 0;
+	leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
+	leaf->lf_next = 0;
+	leaf->lf_inode = cpu_to_be64(ip->i_no_addr);
+	leaf->lf_dist = cpu_to_be32(1);
+	leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+	leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+	memset(leaf->lf_reserved2, 0, sizeof(leaf->lf_reserved2));
+	dent = (struct gfs2_dirent *)(leaf+1);
+	gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
+	*pbh = bh;
+	return leaf;
+}
+
+/**
+ * dir_make_exhash - Convert a stuffed directory into an ExHash directory
+ * @dip: The GFS2 inode
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int dir_make_exhash(struct inode *inode)
+{
+	struct gfs2_inode *dip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct gfs2_dirent *dent;
+	struct qstr args;
+	struct buffer_head *bh, *dibh;
+	struct gfs2_leaf *leaf;
+	int y;
+	u32 x;
+	__be64 *lp;
+	u64 bn;
+	int error;
+
+	error = gfs2_meta_inode_buffer(dip, &dibh);
+	if (error)
+		return error;
+
+	/*  Turn over a new leaf  */
+
+	leaf = new_leaf(inode, &bh, 0);
+	if (!leaf)
+		return -ENOSPC;
+	bn = bh->b_blocknr;
+
+	gfs2_assert(sdp, dip->i_entries < (1 << 16));
+	leaf->lf_entries = cpu_to_be16(dip->i_entries);
+
+	/*  Copy dirents  */
+
+	gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
+			     sizeof(struct gfs2_dinode));
+
+	/*  Find last entry  */
+
+	x = 0;
+	args.len = bh->b_size - sizeof(struct gfs2_dinode) +
+		   sizeof(struct gfs2_leaf);
+	args.name = bh->b_data;
+	dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
+				gfs2_dirent_last, &args, NULL);
+	if (!dent) {
+		brelse(bh);
+		brelse(dibh);
+		return -EIO;
+	}
+	if (IS_ERR(dent)) {
+		brelse(bh);
+		brelse(dibh);
+		return PTR_ERR(dent);
+	}
+
+	/*  Adjust the last dirent's record length
+	   (Remember that dent still points to the last entry.)  */
+
+	dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
+		sizeof(struct gfs2_dinode) -
+		sizeof(struct gfs2_leaf));
+
+	brelse(bh);
+
+	/*  We're done with the new leaf block, now setup the new
+	    hash table.  */
+
+	gfs2_trans_add_meta(dip->i_gl, dibh);
+	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
+
+	lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
+
+	for (x = sdp->sd_hash_ptrs; x--; lp++)
+		*lp = cpu_to_be64(bn);
+
+	i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
+	gfs2_add_inode_blocks(&dip->i_inode, 1);
+	dip->i_diskflags |= GFS2_DIF_EXHASH;
+
+	for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
+	dip->i_depth = y;
+
+	gfs2_dinode_out(dip, dibh->b_data);
+
+	brelse(dibh);
+
+	return 0;
+}
+
+/**
+ * dir_split_leaf - Split a leaf block into two
+ * @dip: The GFS2 inode
+ * @index:
+ * @leaf_no:
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+static int dir_split_leaf(struct inode *inode, const struct qstr *name)
+{
+	struct gfs2_inode *dip = GFS2_I(inode);
+	struct buffer_head *nbh, *obh, *dibh;
+	struct gfs2_leaf *nleaf, *oleaf;
+	struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
+	u32 start, len, half_len, divider;
+	u64 bn, leaf_no;
+	__be64 *lp;
+	u32 index;
+	int x, moved = 0;
+	int error;
+
+	index = name->hash >> (32 - dip->i_depth);
+	error = get_leaf_nr(dip, index, &leaf_no);
+	if (error)
+		return error;
+
+	/*  Get the old leaf block  */
+	error = get_leaf(dip, leaf_no, &obh);
+	if (error)
+		return error;
+
+	oleaf = (struct gfs2_leaf *)obh->b_data;
+	if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
+		brelse(obh);
+		return 1; /* can't split */
+	}
+
+	gfs2_trans_add_meta(dip->i_gl, obh);
+
+	nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
+	if (!nleaf) {
+		brelse(obh);
+		return -ENOSPC;
+	}
+	bn = nbh->b_blocknr;
+
+	/*  Compute the start and len of leaf pointers in the hash table.  */
+	len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
+	half_len = len >> 1;
+	if (!half_len) {
+		pr_warn("i_depth %u lf_depth %u index %u\n",
+			dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
+		gfs2_consist_inode(dip);
+		error = -EIO;
+		goto fail_brelse;
+	}
+
+	start = (index & ~(len - 1));
+
+	/* Change the pointers.
+	   Don't bother distinguishing stuffed from non-stuffed.
+	   This code is complicated enough already. */
+	lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
+	if (!lp) {
+		error = -ENOMEM;
+		goto fail_brelse;
+	}
+
+	/*  Change the pointers  */
+	for (x = 0; x < half_len; x++)
+		lp[x] = cpu_to_be64(bn);
+
+	gfs2_dir_hash_inval(dip);
+
+	error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
+				    half_len * sizeof(u64));
+	if (error != half_len * sizeof(u64)) {
+		if (error >= 0)
+			error = -EIO;
+		goto fail_lpfree;
+	}
+
+	kfree(lp);
+
+	/*  Compute the divider  */
+	divider = (start + half_len) << (32 - dip->i_depth);
+
+	/*  Copy the entries  */
+	dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
+
+	do {
+		next = dent;
+		if (dirent_next(dip, obh, &next))
+			next = NULL;
+
+		if (!gfs2_dirent_sentinel(dent) &&
+		    be32_to_cpu(dent->de_hash) < divider) {
+			struct qstr str;
+			str.name = (char*)(dent+1);
+			str.len = be16_to_cpu(dent->de_name_len);
+			str.hash = be32_to_cpu(dent->de_hash);
+			new = gfs2_dirent_alloc(inode, nbh, &str);
+			if (IS_ERR(new)) {
+				error = PTR_ERR(new);
+				break;
+			}
+
+			new->de_inum = dent->de_inum; /* No endian worries */
+			new->de_type = dent->de_type; /* No endian worries */
+			be16_add_cpu(&nleaf->lf_entries, 1);
+
+			dirent_del(dip, obh, prev, dent);
+
+			if (!oleaf->lf_entries)
+				gfs2_consist_inode(dip);
+			be16_add_cpu(&oleaf->lf_entries, -1);
+
+			if (!prev)
+				prev = dent;
+
+			moved = 1;
+		} else {
+			prev = dent;
+		}
+		dent = next;
+	} while (dent);
+
+	oleaf->lf_depth = nleaf->lf_depth;
+
+	error = gfs2_meta_inode_buffer(dip, &dibh);
+	if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
+		gfs2_trans_add_meta(dip->i_gl, dibh);
+		gfs2_add_inode_blocks(&dip->i_inode, 1);
+		gfs2_dinode_out(dip, dibh->b_data);
+		brelse(dibh);
+	}
+
+	brelse(obh);
+	brelse(nbh);
+
+	return error;
+
+fail_lpfree:
+	kfree(lp);
+
+fail_brelse:
+	brelse(obh);
+	brelse(nbh);
+	return error;
+}
+
+/**
+ * dir_double_exhash - Double size of ExHash table
+ * @dip: The GFS2 dinode
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+static int dir_double_exhash(struct gfs2_inode *dip)
+{
+	struct buffer_head *dibh;
+	u32 hsize;
+	u32 hsize_bytes;
+	__be64 *hc;
+	__be64 *hc2, *h;
+	int x;
+	int error = 0;
+
+	hsize = 1 << dip->i_depth;
+	hsize_bytes = hsize * sizeof(__be64);
+
+	hc = gfs2_dir_get_hash_table(dip);
+	if (IS_ERR(hc))
+		return PTR_ERR(hc);
+
+	hc2 = kmalloc(hsize_bytes * 2, GFP_NOFS | __GFP_NOWARN);
+	if (hc2 == NULL)
+		hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS, PAGE_KERNEL);
+
+	if (!hc2)
+		return -ENOMEM;
+
+	h = hc2;
+	error = gfs2_meta_inode_buffer(dip, &dibh);
+	if (error)
+		goto out_kfree;
+
+	for (x = 0; x < hsize; x++) {
+		*h++ = *hc;
+		*h++ = *hc;
+		hc++;
+	}
+
+	error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
+	if (error != (hsize_bytes * 2))
+		goto fail;
+
+	gfs2_dir_hash_inval(dip);
+	dip->i_hash_cache = hc2;
+	dip->i_depth++;
+	gfs2_dinode_out(dip, dibh->b_data);
+	brelse(dibh);
+	return 0;
+
+fail:
+	/* Replace original hash table & size */
+	gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
+	i_size_write(&dip->i_inode, hsize_bytes);
+	gfs2_dinode_out(dip, dibh->b_data);
+	brelse(dibh);
+out_kfree:
+	kvfree(hc2);
+	return error;
+}
+
+/**
+ * compare_dents - compare directory entries by hash value
+ * @a: first dent
+ * @b: second dent
+ *
+ * When comparing the hash entries of @a to @b:
+ *   gt: returns 1
+ *   lt: returns -1
+ *   eq: returns 0
+ */
+
+static int compare_dents(const void *a, const void *b)
+{
+	const struct gfs2_dirent *dent_a, *dent_b;
+	u32 hash_a, hash_b;
+	int ret = 0;
+
+	dent_a = *(const struct gfs2_dirent **)a;
+	hash_a = be32_to_cpu(dent_a->de_hash);
+
+	dent_b = *(const struct gfs2_dirent **)b;
+	hash_b = be32_to_cpu(dent_b->de_hash);
+
+	if (hash_a > hash_b)
+		ret = 1;
+	else if (hash_a < hash_b)
+		ret = -1;
+	else {
+		unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
+		unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
+
+		if (len_a > len_b)
+			ret = 1;
+		else if (len_a < len_b)
+			ret = -1;
+		else
+			ret = memcmp(dent_a + 1, dent_b + 1, len_a);
+	}
+
+	return ret;
+}
+
+/**
+ * do_filldir_main - read out directory entries
+ * @dip: The GFS2 inode
+ * @ctx: what to feed the entries to
+ * @darr: an array of struct gfs2_dirent pointers to read
+ * @entries: the number of entries in darr
+ * @copied: pointer to int that's non-zero if a entry has been copied out
+ *
+ * Jump through some hoops to make sure that if there are hash collsions,
+ * they are read out at the beginning of a buffer.  We want to minimize
+ * the possibility that they will fall into different readdir buffers or
+ * that someone will want to seek to that location.
+ *
+ * Returns: errno, >0 if the actor tells you to stop
+ */
+
+static int do_filldir_main(struct gfs2_inode *dip, struct dir_context *ctx,
+			   const struct gfs2_dirent **darr, u32 entries,
+			   int *copied)
+{
+	const struct gfs2_dirent *dent, *dent_next;
+	u64 off, off_next;
+	unsigned int x, y;
+	int run = 0;
+
+	sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
+
+	dent_next = darr[0];
+	off_next = be32_to_cpu(dent_next->de_hash);
+	off_next = gfs2_disk_hash2offset(off_next);
+
+	for (x = 0, y = 1; x < entries; x++, y++) {
+		dent = dent_next;
+		off = off_next;
+
+		if (y < entries) {
+			dent_next = darr[y];
+			off_next = be32_to_cpu(dent_next->de_hash);
+			off_next = gfs2_disk_hash2offset(off_next);
+
+			if (off < ctx->pos)
+				continue;
+			ctx->pos = off;
+
+			if (off_next == off) {
+				if (*copied && !run)
+					return 1;
+				run = 1;
+			} else
+				run = 0;
+		} else {
+			if (off < ctx->pos)
+				continue;
+			ctx->pos = off;
+		}
+
+		if (!dir_emit(ctx, (const char *)(dent + 1),
+				be16_to_cpu(dent->de_name_len),
+				be64_to_cpu(dent->de_inum.no_addr),
+				be16_to_cpu(dent->de_type)))
+			return 1;
+
+		*copied = 1;
+	}
+
+	/* Increment the ctx->pos by one, so the next time we come into the
+	   do_filldir fxn, we get the next entry instead of the last one in the
+	   current leaf */
+
+	ctx->pos++;
+
+	return 0;
+}
+
+static void *gfs2_alloc_sort_buffer(unsigned size)
+{
+	void *ptr = NULL;
+
+	if (size < KMALLOC_MAX_SIZE)
+		ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
+	if (!ptr)
+		ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
+	return ptr;
+}
+
+static int gfs2_dir_read_leaf(struct inode *inode, struct dir_context *ctx,
+			      int *copied, unsigned *depth,
+			      u64 leaf_no)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct buffer_head *bh;
+	struct gfs2_leaf *lf;
+	unsigned entries = 0, entries2 = 0;
+	unsigned leaves = 0;
+	const struct gfs2_dirent **darr, *dent;
+	struct dirent_gather g;
+	struct buffer_head **larr;
+	int leaf = 0;
+	int error, i;
+	u64 lfn = leaf_no;
+
+	do {
+		error = get_leaf(ip, lfn, &bh);
+		if (error)
+			goto out;
+		lf = (struct gfs2_leaf *)bh->b_data;
+		if (leaves == 0)
+			*depth = be16_to_cpu(lf->lf_depth);
+		entries += be16_to_cpu(lf->lf_entries);
+		leaves++;
+		lfn = be64_to_cpu(lf->lf_next);
+		brelse(bh);
+	} while(lfn);
+
+	if (!entries)
+		return 0;
+
+	error = -ENOMEM;
+	/*
+	 * The extra 99 entries are not normally used, but are a buffer
+	 * zone in case the number of entries in the leaf is corrupt.
+	 * 99 is the maximum number of entries that can fit in a single
+	 * leaf block.
+	 */
+	larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
+	if (!larr)
+		goto out;
+	darr = (const struct gfs2_dirent **)(larr + leaves);
+	g.pdent = darr;
+	g.offset = 0;
+	lfn = leaf_no;
+
+	do {
+		error = get_leaf(ip, lfn, &bh);
+		if (error)
+			goto out_free;
+		lf = (struct gfs2_leaf *)bh->b_data;
+		lfn = be64_to_cpu(lf->lf_next);
+		if (lf->lf_entries) {
+			entries2 += be16_to_cpu(lf->lf_entries);
+			dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+						gfs2_dirent_gather, NULL, &g);
+			error = PTR_ERR(dent);
+			if (IS_ERR(dent))
+				goto out_free;
+			if (entries2 != g.offset) {
+				fs_warn(sdp, "Number of entries corrupt in dir "
+						"leaf %llu, entries2 (%u) != "
+						"g.offset (%u)\n",
+					(unsigned long long)bh->b_blocknr,
+					entries2, g.offset);
+					
+				error = -EIO;
+				goto out_free;
+			}
+			error = 0;
+			larr[leaf++] = bh;
+		} else {
+			brelse(bh);
+		}
+	} while(lfn);
+
+	BUG_ON(entries2 != entries);
+	error = do_filldir_main(ip, ctx, darr, entries, copied);
+out_free:
+	for(i = 0; i < leaf; i++)
+		brelse(larr[i]);
+	kvfree(larr);
+out:
+	return error;
+}
+
+/**
+ * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
+ *
+ * Note: we can't calculate each index like dir_e_read can because we don't
+ * have the leaf, and therefore we don't have the depth, and therefore we
+ * don't have the length. So we have to just read enough ahead to make up
+ * for the loss of information.
+ */
+static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
+			       struct file_ra_state *f_ra)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_glock *gl = ip->i_gl;
+	struct buffer_head *bh;
+	u64 blocknr = 0, last;
+	unsigned count;
+
+	/* First check if we've already read-ahead for the whole range. */
+	if (index + MAX_RA_BLOCKS < f_ra->start)
+		return;
+
+	f_ra->start = max((pgoff_t)index, f_ra->start);
+	for (count = 0; count < MAX_RA_BLOCKS; count++) {
+		if (f_ra->start >= hsize) /* if exceeded the hash table */
+			break;
+
+		last = blocknr;
+		blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
+		f_ra->start++;
+		if (blocknr == last)
+			continue;
+
+		bh = gfs2_getbuf(gl, blocknr, 1);
+		if (trylock_buffer(bh)) {
+			if (buffer_uptodate(bh)) {
+				unlock_buffer(bh);
+				brelse(bh);
+				continue;
+			}
+			bh->b_end_io = end_buffer_read_sync;
+			submit_bh(READA | REQ_META, bh);
+			continue;
+		}
+		brelse(bh);
+	}
+}
+
+/**
+ * dir_e_read - Reads the entries from a directory into a filldir buffer
+ * @dip: dinode pointer
+ * @ctx: actor to feed the entries to
+ *
+ * Returns: errno
+ */
+
+static int dir_e_read(struct inode *inode, struct dir_context *ctx,
+		      struct file_ra_state *f_ra)
+{
+	struct gfs2_inode *dip = GFS2_I(inode);
+	u32 hsize, len = 0;
+	u32 hash, index;
+	__be64 *lp;
+	int copied = 0;
+	int error = 0;
+	unsigned depth = 0;
+
+	hsize = 1 << dip->i_depth;
+	hash = gfs2_dir_offset2hash(ctx->pos);
+	index = hash >> (32 - dip->i_depth);
+
+	if (dip->i_hash_cache == NULL)
+		f_ra->start = 0;
+	lp = gfs2_dir_get_hash_table(dip);
+	if (IS_ERR(lp))
+		return PTR_ERR(lp);
+
+	gfs2_dir_readahead(inode, hsize, index, f_ra);
+
+	while (index < hsize) {
+		error = gfs2_dir_read_leaf(inode, ctx,
+					   &copied, &depth,
+					   be64_to_cpu(lp[index]));
+		if (error)
+			break;
+
+		len = 1 << (dip->i_depth - depth);
+		index = (index & ~(len - 1)) + len;
+	}
+
+	if (error > 0)
+		error = 0;
+	return error;
+}
+
+int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
+		  struct file_ra_state *f_ra)
+{
+	struct gfs2_inode *dip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct dirent_gather g;
+	const struct gfs2_dirent **darr, *dent;
+	struct buffer_head *dibh;
+	int copied = 0;
+	int error;
+
+	if (!dip->i_entries)
+		return 0;
+
+	if (dip->i_diskflags & GFS2_DIF_EXHASH)
+		return dir_e_read(inode, ctx, f_ra);
+
+	if (!gfs2_is_stuffed(dip)) {
+		gfs2_consist_inode(dip);
+		return -EIO;
+	}
+
+	error = gfs2_meta_inode_buffer(dip, &dibh);
+	if (error)
+		return error;
+
+	error = -ENOMEM;
+	/* 96 is max number of dirents which can be stuffed into an inode */
+	darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
+	if (darr) {
+		g.pdent = darr;
+		g.offset = 0;
+		dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
+					gfs2_dirent_gather, NULL, &g);
+		if (IS_ERR(dent)) {
+			error = PTR_ERR(dent);
+			goto out;
+		}
+		if (dip->i_entries != g.offset) {
+			fs_warn(sdp, "Number of entries corrupt in dir %llu, "
+				"ip->i_entries (%u) != g.offset (%u)\n",
+				(unsigned long long)dip->i_no_addr,
+				dip->i_entries,
+				g.offset);
+			error = -EIO;
+			goto out;
+		}
+		error = do_filldir_main(dip, ctx, darr,
+					dip->i_entries, &copied);
+out:
+		kfree(darr);
+	}
+
+	if (error > 0)
+		error = 0;
+
+	brelse(dibh);
+
+	return error;
+}
+
+/**
+ * gfs2_dir_search - Search a directory
+ * @dip: The GFS2 dir inode
+ * @name: The name we are looking up
+ * @fail_on_exist: Fail if the name exists rather than looking it up
+ *
+ * This routine searches a directory for a file or another directory.
+ * Assumes a glock is held on dip.
+ *
+ * Returns: errno
+ */
+
+struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,
+			      bool fail_on_exist)
+{
+	struct buffer_head *bh;
+	struct gfs2_dirent *dent;
+	u64 addr, formal_ino;
+	u16 dtype;
+
+	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
+	if (dent) {
+		if (IS_ERR(dent))
+			return ERR_CAST(dent);
+		dtype = be16_to_cpu(dent->de_type);
+		addr = be64_to_cpu(dent->de_inum.no_addr);
+		formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);
+		brelse(bh);
+		if (fail_on_exist)
+			return ERR_PTR(-EEXIST);
+		return gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino, 0);
+	}
+	return ERR_PTR(-ENOENT);
+}
+
+int gfs2_dir_check(struct inode *dir, const struct qstr *name,
+		   const struct gfs2_inode *ip)
+{
+	struct buffer_head *bh;
+	struct gfs2_dirent *dent;
+	int ret = -ENOENT;
+
+	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
+	if (dent) {
+		if (IS_ERR(dent))
+			return PTR_ERR(dent);
+		if (ip) {
+			if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
+				goto out;
+			if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
+			    ip->i_no_formal_ino)
+				goto out;
+			if (unlikely(IF2DT(ip->i_inode.i_mode) !=
+			    be16_to_cpu(dent->de_type))) {
+				gfs2_consist_inode(GFS2_I(dir));
+				ret = -EIO;
+				goto out;
+			}
+		}
+		ret = 0;
+out:
+		brelse(bh);
+	}
+	return ret;
+}
+
+/**
+ * dir_new_leaf - Add a new leaf onto hash chain
+ * @inode: The directory
+ * @name: The name we are adding
+ *
+ * This adds a new dir leaf onto an existing leaf when there is not
+ * enough space to add a new dir entry. This is a last resort after
+ * we've expanded the hash table to max size and also split existing
+ * leaf blocks, so it will only occur for very large directories.
+ *
+ * The dist parameter is set to 1 for leaf blocks directly attached
+ * to the hash table, 2 for one layer of indirection, 3 for two layers
+ * etc. We are thus able to tell the difference between an old leaf
+ * with dist set to zero (i.e. "don't know") and a new one where we
+ * set this information for debug/fsck purposes.
+ *
+ * Returns: 0 on success, or -ve on error
+ */
+
+static int dir_new_leaf(struct inode *inode, const struct qstr *name)
+{
+	struct buffer_head *bh, *obh;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_leaf *leaf, *oleaf;
+	u32 dist = 1;
+	int error;
+	u32 index;
+	u64 bn;
+
+	index = name->hash >> (32 - ip->i_depth);
+	error = get_first_leaf(ip, index, &obh);
+	if (error)
+		return error;
+	do {
+		dist++;
+		oleaf = (struct gfs2_leaf *)obh->b_data;
+		bn = be64_to_cpu(oleaf->lf_next);
+		if (!bn)
+			break;
+		brelse(obh);
+		error = get_leaf(ip, bn, &obh);
+		if (error)
+			return error;
+	} while(1);
+
+	gfs2_trans_add_meta(ip->i_gl, obh);
+
+	leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
+	if (!leaf) {
+		brelse(obh);
+		return -ENOSPC;
+	}
+	leaf->lf_dist = cpu_to_be32(dist);
+	oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
+	brelse(bh);
+	brelse(obh);
+
+	error = gfs2_meta_inode_buffer(ip, &bh);
+	if (error)
+		return error;
+	gfs2_trans_add_meta(ip->i_gl, bh);
+	gfs2_add_inode_blocks(&ip->i_inode, 1);
+	gfs2_dinode_out(ip, bh->b_data);
+	brelse(bh);
+	return 0;
+}
+
+static u16 gfs2_inode_ra_len(const struct gfs2_inode *ip)
+{
+	u64 where = ip->i_no_addr + 1;
+	if (ip->i_eattr == where)
+		return 1;
+	return 0;
+}
+
+/**
+ * gfs2_dir_add - Add new filename into directory
+ * @inode: The directory inode
+ * @name: The new name
+ * @nip: The GFS2 inode to be linked in to the directory
+ * @da: The directory addition info
+ *
+ * If the call to gfs2_diradd_alloc_required resulted in there being
+ * no need to allocate any new directory blocks, then it will contain
+ * a pointer to the directory entry and the bh in which it resides. We
+ * can use that without having to repeat the search. If there was no
+ * free space, then we must now create more space.
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+int gfs2_dir_add(struct inode *inode, const struct qstr *name,
+		 const struct gfs2_inode *nip, struct gfs2_diradd *da)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct buffer_head *bh = da->bh;
+	struct gfs2_dirent *dent = da->dent;
+	struct timespec tv;
+	struct gfs2_leaf *leaf;
+	int error;
+
+	while(1) {
+		if (da->bh == NULL) {
+			dent = gfs2_dirent_search(inode, name,
+						  gfs2_dirent_find_space, &bh);
+		}
+		if (dent) {
+			if (IS_ERR(dent))
+				return PTR_ERR(dent);
+			dent = gfs2_init_dirent(inode, dent, name, bh);
+			gfs2_inum_out(nip, dent);
+			dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
+			dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip));
+			tv = CURRENT_TIME;
+			if (ip->i_diskflags & GFS2_DIF_EXHASH) {
+				leaf = (struct gfs2_leaf *)bh->b_data;
+				be16_add_cpu(&leaf->lf_entries, 1);
+				leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+				leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+			}
+			da->dent = NULL;
+			da->bh = NULL;
+			brelse(bh);
+			ip->i_entries++;
+			ip->i_inode.i_mtime = ip->i_inode.i_ctime = tv;
+			if (S_ISDIR(nip->i_inode.i_mode))
+				inc_nlink(&ip->i_inode);
+			mark_inode_dirty(inode);
+			error = 0;
+			break;
+		}
+		if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
+			error = dir_make_exhash(inode);
+			if (error)
+				break;
+			continue;
+		}
+		error = dir_split_leaf(inode, name);
+		if (error == 0)
+			continue;
+		if (error < 0)
+			break;
+		if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
+			error = dir_double_exhash(ip);
+			if (error)
+				break;
+			error = dir_split_leaf(inode, name);
+			if (error < 0)
+				break;
+			if (error == 0)
+				continue;
+		}
+		error = dir_new_leaf(inode, name);
+		if (!error)
+			continue;
+		error = -ENOSPC;
+		break;
+	}
+	return error;
+}
+
+
+/**
+ * gfs2_dir_del - Delete a directory entry
+ * @dip: The GFS2 inode
+ * @filename: The filename
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
+{
+	const struct qstr *name = &dentry->d_name;
+	struct gfs2_dirent *dent, *prev = NULL;
+	struct buffer_head *bh;
+	struct timespec tv = CURRENT_TIME;
+
+	/* Returns _either_ the entry (if its first in block) or the
+	   previous entry otherwise */
+	dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
+	if (!dent) {
+		gfs2_consist_inode(dip);
+		return -EIO;
+	}
+	if (IS_ERR(dent)) {
+		gfs2_consist_inode(dip);
+		return PTR_ERR(dent);
+	}
+	/* If not first in block, adjust pointers accordingly */
+	if (gfs2_dirent_find(dent, name, NULL) == 0) {
+		prev = dent;
+		dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
+	}
+
+	dirent_del(dip, bh, prev, dent);
+	if (dip->i_diskflags & GFS2_DIF_EXHASH) {
+		struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
+		u16 entries = be16_to_cpu(leaf->lf_entries);
+		if (!entries)
+			gfs2_consist_inode(dip);
+		leaf->lf_entries = cpu_to_be16(--entries);
+		leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+		leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+	}
+	brelse(bh);
+
+	if (!dip->i_entries)
+		gfs2_consist_inode(dip);
+	dip->i_entries--;
+	dip->i_inode.i_mtime = dip->i_inode.i_ctime = tv;
+	if (d_is_dir(dentry))
+		drop_nlink(&dip->i_inode);
+	mark_inode_dirty(&dip->i_inode);
+
+	return 0;
+}
+
+/**
+ * gfs2_dir_mvino - Change inode number of directory entry
+ * @dip: The GFS2 inode
+ * @filename:
+ * @new_inode:
+ *
+ * This routine changes the inode number of a directory entry.  It's used
+ * by rename to change ".." when a directory is moved.
+ * Assumes a glock is held on dvp.
+ *
+ * Returns: errno
+ */
+
+int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
+		   const struct gfs2_inode *nip, unsigned int new_type)
+{
+	struct buffer_head *bh;
+	struct gfs2_dirent *dent;
+	int error;
+
+	dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
+	if (!dent) {
+		gfs2_consist_inode(dip);
+		return -EIO;
+	}
+	if (IS_ERR(dent))
+		return PTR_ERR(dent);
+
+	gfs2_trans_add_meta(dip->i_gl, bh);
+	gfs2_inum_out(nip, dent);
+	dent->de_type = cpu_to_be16(new_type);
+
+	if (dip->i_diskflags & GFS2_DIF_EXHASH) {
+		brelse(bh);
+		error = gfs2_meta_inode_buffer(dip, &bh);
+		if (error)
+			return error;
+		gfs2_trans_add_meta(dip->i_gl, bh);
+	}
+
+	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
+	gfs2_dinode_out(dip, bh->b_data);
+	brelse(bh);
+	return 0;
+}
+
+/**
+ * leaf_dealloc - Deallocate a directory leaf
+ * @dip: the directory
+ * @index: the hash table offset in the directory
+ * @len: the number of pointers to this leaf
+ * @leaf_no: the leaf number
+ * @leaf_bh: buffer_head for the starting leaf
+ * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
+ *
+ * Returns: errno
+ */
+
+static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
+			u64 leaf_no, struct buffer_head *leaf_bh,
+			int last_dealloc)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
+	struct gfs2_leaf *tmp_leaf;
+	struct gfs2_rgrp_list rlist;
+	struct buffer_head *bh, *dibh;
+	u64 blk, nblk;
+	unsigned int rg_blocks = 0, l_blocks = 0;
+	char *ht;
+	unsigned int x, size = len * sizeof(u64);
+	int error;
+
+	error = gfs2_rindex_update(sdp);
+	if (error)
+		return error;
+
+	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
+
+	ht = kzalloc(size, GFP_NOFS | __GFP_NOWARN);
+	if (ht == NULL)
+		ht = __vmalloc(size, GFP_NOFS | __GFP_NOWARN | __GFP_ZERO,
+			       PAGE_KERNEL);
+	if (!ht)
+		return -ENOMEM;
+
+	error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
+	if (error)
+		goto out;
+
+	/*  Count the number of leaves  */
+	bh = leaf_bh;
+
+	for (blk = leaf_no; blk; blk = nblk) {
+		if (blk != leaf_no) {
+			error = get_leaf(dip, blk, &bh);
+			if (error)
+				goto out_rlist;
+		}
+		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
+		nblk = be64_to_cpu(tmp_leaf->lf_next);
+		if (blk != leaf_no)
+			brelse(bh);
+
+		gfs2_rlist_add(dip, &rlist, blk);
+		l_blocks++;
+	}
+
+	gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
+
+	for (x = 0; x < rlist.rl_rgrps; x++) {
+		struct gfs2_rgrpd *rgd;
+		rgd = rlist.rl_ghs[x].gh_gl->gl_object;
+		rg_blocks += rgd->rd_length;
+	}
+
+	error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
+	if (error)
+		goto out_rlist;
+
+	error = gfs2_trans_begin(sdp,
+			rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
+			RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
+	if (error)
+		goto out_rg_gunlock;
+
+	bh = leaf_bh;
+
+	for (blk = leaf_no; blk; blk = nblk) {
+		if (blk != leaf_no) {
+			error = get_leaf(dip, blk, &bh);
+			if (error)
+				goto out_end_trans;
+		}
+		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
+		nblk = be64_to_cpu(tmp_leaf->lf_next);
+		if (blk != leaf_no)
+			brelse(bh);
+
+		gfs2_free_meta(dip, blk, 1);
+		gfs2_add_inode_blocks(&dip->i_inode, -1);
+	}
+
+	error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
+	if (error != size) {
+		if (error >= 0)
+			error = -EIO;
+		goto out_end_trans;
+	}
+
+	error = gfs2_meta_inode_buffer(dip, &dibh);
+	if (error)
+		goto out_end_trans;
+
+	gfs2_trans_add_meta(dip->i_gl, dibh);
+	/* On the last dealloc, make this a regular file in case we crash.
+	   (We don't want to free these blocks a second time.)  */
+	if (last_dealloc)
+		dip->i_inode.i_mode = S_IFREG;
+	gfs2_dinode_out(dip, dibh->b_data);
+	brelse(dibh);
+
+out_end_trans:
+	gfs2_trans_end(sdp);
+out_rg_gunlock:
+	gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
+out_rlist:
+	gfs2_rlist_free(&rlist);
+	gfs2_quota_unhold(dip);
+out:
+	kvfree(ht);
+	return error;
+}
+
+/**
+ * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
+ * @dip: the directory
+ *
+ * Dealloc all on-disk directory leaves to FREEMETA state
+ * Change on-disk inode type to "regular file"
+ *
+ * Returns: errno
+ */
+
+int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
+{
+	struct buffer_head *bh;
+	struct gfs2_leaf *leaf;
+	u32 hsize, len;
+	u32 index = 0, next_index;
+	__be64 *lp;
+	u64 leaf_no;
+	int error = 0, last;
+
+	hsize = 1 << dip->i_depth;
+
+	lp = gfs2_dir_get_hash_table(dip);
+	if (IS_ERR(lp))
+		return PTR_ERR(lp);
+
+	while (index < hsize) {
+		leaf_no = be64_to_cpu(lp[index]);
+		if (leaf_no) {
+			error = get_leaf(dip, leaf_no, &bh);
+			if (error)
+				goto out;
+			leaf = (struct gfs2_leaf *)bh->b_data;
+			len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
+
+			next_index = (index & ~(len - 1)) + len;
+			last = ((next_index >= hsize) ? 1 : 0);
+			error = leaf_dealloc(dip, index, len, leaf_no, bh,
+					     last);
+			brelse(bh);
+			if (error)
+				goto out;
+			index = next_index;
+		} else
+			index++;
+	}
+
+	if (index != hsize) {
+		gfs2_consist_inode(dip);
+		error = -EIO;
+	}
+
+out:
+
+	return error;
+}
+
+/**
+ * gfs2_diradd_alloc_required - find if adding entry will require an allocation
+ * @ip: the file being written to
+ * @filname: the filename that's going to be added
+ * @da: The structure to return dir alloc info
+ *
+ * Returns: 0 if ok, -ve on error
+ */
+
+int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name,
+			       struct gfs2_diradd *da)
+{
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	const unsigned int extra = sizeof(struct gfs2_dinode) - sizeof(struct gfs2_leaf);
+	struct gfs2_dirent *dent;
+	struct buffer_head *bh;
+
+	da->nr_blocks = 0;
+	da->bh = NULL;
+	da->dent = NULL;
+
+	dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
+	if (!dent) {
+		da->nr_blocks = sdp->sd_max_dirres;
+		if (!(ip->i_diskflags & GFS2_DIF_EXHASH) &&
+		    (GFS2_DIRENT_SIZE(name->len) < extra))
+			da->nr_blocks = 1;
+		return 0;
+	}
+	if (IS_ERR(dent))
+		return PTR_ERR(dent);
+
+	if (da->save_loc) {
+		da->bh = bh;
+		da->dent = dent;
+	} else {
+		brelse(bh);
+	}
+	return 0;
+}
+