dir.c 46.1 KB
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/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

/*
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 * 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_di.di_flags & 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.
 */
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#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/buffer_head.h>
#include <linux/sort.h>
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#include <linux/gfs2_ondisk.h>
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#include <linux/crc32.h>
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#include <linux/vmalloc.h>
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#include "gfs2.h"
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#include "lm_interface.h"
#include "incore.h"
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#include "dir.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
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#include "bmap.h"
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#include "util.h"
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#define IS_LEAF     1 /* Hashed (leaf) directory */
#define IS_DINODE   2 /* Linear (stuffed dinode block) directory */

#if 1
#define gfs2_disk_hash2offset(h) (((uint64_t)(h)) >> 1)
#define gfs2_dir_offset2hash(p) ((uint32_t)(((uint64_t)(p)) << 1))
#else
#define gfs2_disk_hash2offset(h) (((uint64_t)(h)))
#define gfs2_dir_offset2hash(p) ((uint32_t)(((uint64_t)(p))))
#endif

typedef int (*leaf_call_t) (struct gfs2_inode *dip,
			    uint32_t index, uint32_t len, uint64_t leaf_no,
			    void *data);

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int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, uint64_t block,
			    struct buffer_head **bhp)
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{
	struct buffer_head *bh;

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	bh = gfs2_meta_new(ip->i_gl, block);
	gfs2_trans_add_bh(ip->i_gl, bh, 1);
	gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
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	*bhp = bh;
	return 0;
}

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static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, uint64_t block,
					struct buffer_head **bhp)
{
	struct buffer_head *bh;
	int error;
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	error = gfs2_meta_read(ip->i_gl, block, DIO_START | DIO_WAIT, &bh);
	if (error)
		return error;
	if (gfs2_metatype_check(ip->i_sbd, bh, GFS2_METATYPE_JD)) {
		brelse(bh);
		return -EIO;
	}
	*bhp = bh;
	return 0;
}
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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_bh(ip->i_gl, dibh, 1);
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	memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
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	if (ip->i_di.di_size < offset + size)
		ip->i_di.di_size = offset + size;
	ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
	gfs2_dinode_out(&ip->i_di, 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,
			       uint64_t offset, unsigned int size)
{
	struct gfs2_sbd *sdp = ip->i_sbd;
	struct buffer_head *dibh;
	uint64_t lblock, dblock;
	uint32_t extlen = 0;
	unsigned int o;
	int copied = 0;
	int error = 0;

	if (!size)
		return 0;

	if (gfs2_is_stuffed(ip) &&
	    offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
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		return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
					      size);
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	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
		return -EINVAL;

	if (gfs2_is_stuffed(ip)) {
		error = gfs2_unstuff_dinode(ip, NULL, NULL);
		if (error)
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			return error;
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	}

	lblock = offset;
	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 = 1;
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			error = gfs2_extent_map(ip->i_vnode, lblock, &new,
						&dblock, &extlen);
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			if (error)
				goto fail;
			error = -EIO;
			if (gfs2_assert_withdraw(sdp, dblock))
				goto fail;
		}

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		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);

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		if (error)
			goto fail;

		gfs2_trans_add_bh(ip->i_gl, bh, 1);
		memcpy(bh->b_data + o, buf, amount);
		brelse(bh);
		if (error)
			goto fail;

		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_di.di_size < offset + copied)
		ip->i_di.di_size = offset + copied;
	ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();

	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
	gfs2_dinode_out(&ip->i_di, dibh->b_data);
	brelse(dibh);

	return copied;
fail:
	if (copied)
		goto out;
	return error;
}

static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, char *buf,
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				 unsigned int offset, unsigned int size)
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{
	struct buffer_head *dibh;
	int error;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		offset += sizeof(struct gfs2_dinode);
		memcpy(buf, dibh->b_data + offset, 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
 * @offset: File offset to begin jdata_readng from
 * @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, char *buf,
			      uint64_t offset, unsigned int size)
{
	struct gfs2_sbd *sdp = ip->i_sbd;
	uint64_t lblock, dblock;
	uint32_t extlen = 0;
	unsigned int o;
	int copied = 0;
	int error = 0;

	if (offset >= ip->i_di.di_size)
		return 0;

	if ((offset + size) > ip->i_di.di_size)
		size = ip->i_di.di_size - offset;

	if (!size)
		return 0;

	if (gfs2_is_stuffed(ip))
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		return gfs2_dir_read_stuffed(ip, buf, (unsigned int)offset,
					     size);
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	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
		return -EINVAL;

	lblock = offset;
	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;
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			error = gfs2_extent_map(ip->i_vnode, lblock, &new,
						&dblock, &extlen);
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			if (error)
				goto fail;
		}

		if (extlen > 1)
			gfs2_meta_ra(ip->i_gl, dblock, extlen);

		if (dblock) {
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			if (new)
				error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
			else
				error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
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			if (error)
				goto fail;
			dblock++;
			extlen--;
		} else
			bh = NULL;

		memcpy(buf, bh->b_data + o, amount);
		brelse(bh);
		if (error)
			goto fail;

		copied += amount;
		lblock++;

		o = sizeof(struct gfs2_meta_header);
	}

	return copied;
fail:
	return (copied) ? copied : error;
}

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typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
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			    const struct qstr *name,
			    void *opaque);
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static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
				     const struct qstr *name, int ret)
{
	if (dent->de_inum.no_addr != 0 &&
	    be32_to_cpu(dent->de_hash) == name->hash &&
	    be16_to_cpu(dent->de_name_len) == name->len &&
	    memcmp((char *)(dent+1), name->name, name->len) == 0)
		return ret;
	return 0;
}

static int gfs2_dirent_find(const struct gfs2_dirent *dent,
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			    const struct qstr *name,
			    void *opaque)
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{
	return __gfs2_dirent_find(dent, name, 1);
}

static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
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			    const struct qstr *name,
			    void *opaque)
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{
	return __gfs2_dirent_find(dent, name, 2);
}

/*
 * name->name holds ptr to start of block.
 * name->len holds size of block.
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 */
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static int gfs2_dirent_last(const struct gfs2_dirent *dent,
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			    const struct qstr *name,
			    void *opaque)
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{
	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;
}
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static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
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				  const struct qstr *name,
				  void *opaque)
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{
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	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);

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	if (!dent->de_inum.no_addr)
		actual = GFS2_DIRENT_SIZE(0);
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	if ((totlen - actual) >= required)
		return 1;
	return 0;
}

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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 (dent->de_inum.no_addr) {
		g->pdent[g->offset++] = dent;
	}
	return 0;
}

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/*
 * 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 && !dent->de_inum.no_addr))
		goto error;
	msg = "name length is greater than space in dirent";
	if (dent->de_inum.no_addr &&
	    unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
		     size))
		goto error;
	return 0;
error:
	printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", msg,
	       first ? "first in block" : "not first in block");
	return -EIO;
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}

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static int gfs2_dirent_offset(const void *buf)
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{
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	const struct gfs2_meta_header *h = buf;
	int offset;
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	BUG_ON(buf == NULL);

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	switch(be32_to_cpu(h->mh_type)) {
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	case GFS2_METATYPE_LF:
		offset = sizeof(struct gfs2_leaf);
		break;
	case GFS2_METATYPE_DI:
		offset = sizeof(struct gfs2_dinode);
		break;
	default:
		goto wrong_type;
	}
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	return offset;
wrong_type:
	printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
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	       be32_to_cpu(h->mh_type));
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	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;
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	ret = gfs2_dirent_offset(buf);
	if (ret < 0)
		goto consist_inode;

	offset = ret;
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	prev = NULL;
	dent = (struct gfs2_dirent *)(buf + offset);
	size = be16_to_cpu(dent->de_rec_len);
	if (gfs2_check_dirent(dent, offset, size, len, 1))
		goto consist_inode;
	do {
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		ret = scan(dent, name, opaque);
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		if (ret)
			break;
		offset += size;
		if (offset == len)
			break;
		prev = dent;
		dent = (struct gfs2_dirent *)(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(inode->u.generic_ip);
	return ERR_PTR(-EIO);
}


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/**
 * dirent_first - Return the first dirent
 * @dip: the directory
 * @bh: The buffer
 * @dent: Pointer to list of dirents
 *
 * return first dirent whether bh points to leaf or stuffed dinode
 *
 * Returns: IS_LEAF, IS_DINODE, or -errno
 */

static int dirent_first(struct gfs2_inode *dip, struct buffer_head *bh,
			struct gfs2_dirent **dent)
{
	struct gfs2_meta_header *h = (struct gfs2_meta_header *)bh->b_data;

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	if (be32_to_cpu(h->mh_type) == GFS2_METATYPE_LF) {
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		if (gfs2_meta_check(dip->i_sbd, bh))
			return -EIO;
		*dent = (struct gfs2_dirent *)(bh->b_data +
					       sizeof(struct gfs2_leaf));
		return IS_LEAF;
	} else {
		if (gfs2_metatype_check(dip->i_sbd, bh, GFS2_METATYPE_DI))
			return -EIO;
		*dent = (struct gfs2_dirent *)(bh->b_data +
					       sizeof(struct gfs2_dinode));
		return IS_DINODE;
	}
}

/**
 * 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 *tmp, *cur;
	char *bh_end;
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	uint16_t cur_rec_len;
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	cur = *dent;
	bh_end = bh->b_data + bh->b_size;
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	cur_rec_len = be16_to_cpu(cur->de_rec_len);
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	if ((char *)cur + cur_rec_len >= bh_end) {
		if ((char *)cur + cur_rec_len > bh_end) {
			gfs2_consist_inode(dip);
			return -EIO;
		}
		return -ENOENT;
	}

	tmp = (struct gfs2_dirent *)((char *)cur + cur_rec_len);

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	if ((char *)tmp + be16_to_cpu(tmp->de_rec_len) > bh_end) {
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		gfs2_consist_inode(dip);
		return -EIO;
	}
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	if (cur_rec_len == 0) {
		gfs2_consist_inode(dip);
		return -EIO;
	}

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        /* Only the first dent could ever have de_inum.no_addr == 0 */
	if (!tmp->de_inum.no_addr) {
		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)
{
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	uint16_t cur_rec_len, prev_rec_len;
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	if (!cur->de_inum.no_addr) {
		gfs2_consist_inode(dip);
		return;
	}

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	gfs2_trans_add_bh(dip->i_gl, bh, 1);
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	/* 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;	/* No endianess worries */
		return;
	}

	/*  Combine this dentry with the previous one.  */

656 657
	prev_rec_len = be16_to_cpu(prev->de_rec_len);
	cur_rec_len = be16_to_cpu(cur->de_rec_len);
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	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;
665
	prev->de_rec_len = cpu_to_be16(prev_rec_len);
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}

668 669 670
/*
 * Takes a dent from which to grab space as an argument. Returns the
 * newly created dent.
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 */
672 673 674 675
static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
					    struct gfs2_dirent *dent,
					    const struct qstr *name,
					    struct buffer_head *bh)
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{
677 678 679 680 681 682 683 684 685 686 687 688 689
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct gfs2_dirent *ndent;
	unsigned offset = 0, totlen;

	if (dent->de_inum.no_addr)
		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_bh(ip->i_gl, bh, 1);
	ndent = (struct gfs2_dirent *)((char *)dent + offset);
	dent->de_rec_len = cpu_to_be16(offset);
	gfs2_qstr2dirent(name, totlen - offset, ndent);
	return ndent;
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}

692 693 694
static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
					     struct buffer_head *bh,
					     const struct qstr *name)
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{
	struct gfs2_dirent *dent;
697 698
	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, 
				gfs2_dirent_find_space, name, NULL);
699 700 701
	if (!dent || IS_ERR(dent))
		return dent;
	return gfs2_init_dirent(inode, dent, name, bh);
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}

static int get_leaf(struct gfs2_inode *dip, uint64_t leaf_no,
		    struct buffer_head **bhp)
{
	int error;

	error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_START | DIO_WAIT, bhp);
	if (!error && gfs2_metatype_check(dip->i_sbd, *bhp, GFS2_METATYPE_LF))
		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, uint32_t index,
		       uint64_t *leaf_out)
{
	uint64_t leaf_no;
	int error;

731
	error = gfs2_dir_read_data(dip, (char *)&leaf_no,
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				    index * sizeof(uint64_t),
				    sizeof(uint64_t));
	if (error != sizeof(uint64_t))
		return (error < 0) ? error : -EIO;

	*leaf_out = be64_to_cpu(leaf_no);

	return 0;
}

static int get_first_leaf(struct gfs2_inode *dip, uint32_t index,
			  struct buffer_head **bh_out)
{
	uint64_t leaf_no;
	int error;

	error = get_leaf_nr(dip, index, &leaf_no);
	if (!error)
		error = get_leaf(dip, leaf_no, bh_out);

	return error;
}

755 756 757 758
static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
					      const struct qstr *name,
					      gfs2_dscan_t scan,
					      struct buffer_head **pbh)
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{
760 761 762
	struct buffer_head *bh;
	struct gfs2_dirent *dent;
	struct gfs2_inode *ip = inode->u.generic_ip;
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	int error;

765 766 767 768 769 770 771 772 773
	if (ip->i_di.di_flags & GFS2_DIF_EXHASH) {
		struct gfs2_leaf *leaf;
		unsigned hsize = 1 << ip->i_di.di_depth;
		unsigned index;
		u64 ln;
		if (hsize * sizeof(u64) != ip->i_di.di_size) {
			gfs2_consist_inode(ip);
			return ERR_PTR(-EIO);
		}
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775 776 777 778 779 780
		index = name->hash >> (32 - ip->i_di.di_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,
781
						scan, name, NULL);
782 783 784 785
			if (dent)
				goto got_dent;
			leaf = (struct gfs2_leaf *)bh->b_data;
			ln = be64_to_cpu(leaf->lf_next);
786
			brelse(bh);
787 788 789 790
			if (!ln)
				break;
			error = get_leaf(ip, ln, &bh);
		} while(!error);
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792
		return error ? ERR_PTR(error) : NULL;
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	}

795 796 797
	error = gfs2_meta_inode_buffer(ip, &bh);
	if (error)
		return ERR_PTR(error);
798
	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
799
got_dent:
800
	if (unlikely(dent == NULL || IS_ERR(dent))) {
801 802 803
		brelse(bh);
		bh = NULL;
	}
804 805 806
	*pbh = bh;
	return dent;
}
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808 809 810 811 812 813 814
static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
{
	struct gfs2_inode *ip = inode->u.generic_ip;
	u64 bn = gfs2_alloc_meta(ip);
	struct buffer_head *bh = gfs2_meta_new(ip->i_gl, bn);
	struct gfs2_leaf *leaf;
	struct gfs2_dirent *dent;
815
	struct qstr name = { .name = "", .len = 0, .hash = 0 };
816 817 818 819 820 821 822 823 824 825 826
	if (!bh)
		return NULL;
	gfs2_trans_add_bh(ip->i_gl, bh, 1);
	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 = cpu_to_be16(0);
	leaf->lf_dirent_format = cpu_to_be16(GFS2_FORMAT_DE);
	leaf->lf_next = cpu_to_be64(0);
	memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
	dent = (struct gfs2_dirent *)(leaf+1);
827
	gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
828 829
	*pbh = bh;
	return leaf;
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}

/**
 * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 * @dip: The GFS2 inode
 *
 * Returns: 0 on success, error code otherwise
 */

839
static int dir_make_exhash(struct inode *inode)
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{
841
	struct gfs2_inode *dip = inode->u.generic_ip;
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	struct gfs2_sbd *sdp = dip->i_sbd;
	struct gfs2_dirent *dent;
844
	struct qstr args;
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845 846 847 848 849 850 851 852 853 854 855 856 857
	struct buffer_head *bh, *dibh;
	struct gfs2_leaf *leaf;
	int y;
	uint32_t x;
	uint64_t *lp, bn;
	int error;

	error = gfs2_meta_inode_buffer(dip, &dibh);
	if (error)
		return error;

	/*  Turn over a new leaf  */

858 859 860 861
	leaf = new_leaf(inode, &bh, 0);
	if (!leaf)
		return -ENOSPC;
	bn = bh->b_blocknr;
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	gfs2_assert(sdp, dip->i_di.di_entries < (1 << 16));
	leaf->lf_entries = cpu_to_be16(dip->i_di.di_entries);

	/*  Copy dirents  */

	gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
			     sizeof(struct gfs2_dinode));

	/*  Find last entry  */

	x = 0;
874 875 876 877
	args.len = bh->b_size - sizeof(struct gfs2_dinode) +
		   sizeof(struct gfs2_leaf);
	args.name = bh->b_data;
	dent = gfs2_dirent_scan(dip->i_vnode, bh->b_data, bh->b_size,
878
				gfs2_dirent_last, &args, NULL);
879 880 881 882 883 884 885 886 887
	if (!dent) {
		brelse(bh);
		brelse(dibh);
		return -EIO;
	}
	if (IS_ERR(dent)) {
		brelse(bh);
		brelse(dibh);
		return PTR_ERR(dent);
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888 889 890 891 892
	}

	/*  Adjust the last dirent's record length
	   (Remember that dent still points to the last entry.)  */

893
	dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
D
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894
		sizeof(struct gfs2_dinode) -
895
		sizeof(struct gfs2_leaf));
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	brelse(bh);

	/*  We're done with the new leaf block, now setup the new
	    hash table.  */

902
	gfs2_trans_add_bh(dip->i_gl, dibh, 1);
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903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933
	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));

	lp = (uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode));

	for (x = sdp->sd_hash_ptrs; x--; lp++)
		*lp = cpu_to_be64(bn);

	dip->i_di.di_size = sdp->sd_sb.sb_bsize / 2;
	dip->i_di.di_blocks++;
	dip->i_di.di_flags |= GFS2_DIF_EXHASH;
	dip->i_di.di_payload_format = 0;

	for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
	dip->i_di.di_depth = y;

	gfs2_dinode_out(&dip->i_di, 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
 */

934
static int dir_split_leaf(struct inode *inode, const struct qstr *name)
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David Teigland 已提交
935
{
936
	struct gfs2_inode *dip = inode->u.generic_ip;
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937 938 939 940
	struct buffer_head *nbh, *obh, *dibh;
	struct gfs2_leaf *nleaf, *oleaf;
	struct gfs2_dirent *dent, *prev = NULL, *next = NULL, *new;
	uint32_t start, len, half_len, divider;
941 942
	uint64_t bn, *lp, leaf_no;
	uint32_t index;
D
David Teigland 已提交
943 944 945
	int x, moved = 0;
	int error;

946 947 948 949
	index = name->hash >> (32 - dip->i_di.di_depth);
	error = get_leaf_nr(dip, index, &leaf_no);
	if (error)
		return error;
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950 951 952 953

	/*  Get the old leaf block  */
	error = get_leaf(dip, leaf_no, &obh);
	if (error)
954
		return error;
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David Teigland 已提交
955 956

	oleaf = (struct gfs2_leaf *)obh->b_data;
957 958 959 960 961 962
	if (dip->i_di.di_depth == be16_to_cpu(oleaf->lf_depth)) {
		brelse(obh);
		return 1; /* can't split */
	}

	gfs2_trans_add_bh(dip->i_gl, obh, 1);
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David Teigland 已提交
963

964 965 966 967 968 969
	nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
	if (!nleaf) {
		brelse(obh);
		return -ENOSPC;
	}
	bn = nbh->b_blocknr;
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970

971
	/*  Compute the start and len of leaf pointers in the hash table.  */
D
David Teigland 已提交
972 973 974
	len = 1 << (dip->i_di.di_depth - be16_to_cpu(oleaf->lf_depth));
	half_len = len >> 1;
	if (!half_len) {
975
		printk(KERN_WARNING "di_depth %u lf_depth %u index %u\n", dip->i_di.di_depth, be16_to_cpu(oleaf->lf_depth), index);
D
David Teigland 已提交
976 977 978 979 980 981 982 983 984 985
		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. */
986
	lp = kmalloc(half_len * sizeof(uint64_t), GFP_NOFS | __GFP_NOFAIL);
D
David Teigland 已提交
987 988 989 990
	/*  Change the pointers  */
	for (x = 0; x < half_len; x++)
		lp[x] = cpu_to_be64(bn);

991
	error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(uint64_t),
992
				    half_len * sizeof(uint64_t));
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David Teigland 已提交
993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
	if (error != half_len * sizeof(uint64_t)) {
		if (error >= 0)
			error = -EIO;
		goto fail_lpfree;
	}

	kfree(lp);

	/*  Compute the divider  */
	divider = (start + half_len) << (32 - dip->i_di.di_depth);

	/*  Copy the entries  */
	dirent_first(dip, obh, &dent);

	do {
		next = dent;
		if (dirent_next(dip, obh, &next))
			next = NULL;

		if (dent->de_inum.no_addr &&
		    be32_to_cpu(dent->de_hash) < divider) {
1014 1015 1016 1017
			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);
1018
			new = gfs2_dirent_alloc(inode, nbh, &str);
1019 1020 1021 1022
			if (IS_ERR(new)) {
				error = PTR_ERR(new);
				break;
			}
D
David Teigland 已提交
1023 1024 1025

			new->de_inum = dent->de_inum; /* No endian worries */
			new->de_type = dent->de_type; /* No endian worries */
1026
			nleaf->lf_entries = cpu_to_be16(be16_to_cpu(nleaf->lf_entries)+1);
D
David Teigland 已提交
1027 1028 1029 1030 1031

			dirent_del(dip, obh, prev, dent);

			if (!oleaf->lf_entries)
				gfs2_consist_inode(dip);
1032
			oleaf->lf_entries = cpu_to_be16(be16_to_cpu(oleaf->lf_entries)-1);
D
David Teigland 已提交
1033 1034 1035 1036 1037

			if (!prev)
				prev = dent;

			moved = 1;
1038
		} else {
D
David Teigland 已提交
1039
			prev = dent;
1040
		}
D
David Teigland 已提交
1041
		dent = next;
1042
	} while (dent);
D
David Teigland 已提交
1043

1044
	oleaf->lf_depth = nleaf->lf_depth;
D
David Teigland 已提交
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057

	error = gfs2_meta_inode_buffer(dip, &dibh);
	if (!gfs2_assert_withdraw(dip->i_sbd, !error)) {
		dip->i_di.di_blocks++;
		gfs2_dinode_out(&dip->i_di, dibh->b_data);
		brelse(dibh);
	}

	brelse(obh);
	brelse(nbh);

	return error;

1058
fail_lpfree:
D
David Teigland 已提交
1059 1060
	kfree(lp);

1061
fail_brelse:
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1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
	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 gfs2_sbd *sdp = dip->i_sbd;
	struct buffer_head *dibh;
	uint32_t hsize;
	uint64_t *buf;
	uint64_t *from, *to;
	uint64_t block;
	int x;
	int error = 0;

	hsize = 1 << dip->i_di.di_depth;
	if (hsize * sizeof(uint64_t) != dip->i_di.di_size) {
		gfs2_consist_inode(dip);
		return -EIO;
	}

	/*  Allocate both the "from" and "to" buffers in one big chunk  */

	buf = kcalloc(3, sdp->sd_hash_bsize, GFP_KERNEL | __GFP_NOFAIL);

	for (block = dip->i_di.di_size >> sdp->sd_hash_bsize_shift; block--;) {
1096
		error = gfs2_dir_read_data(dip, (char *)buf,
D
David Teigland 已提交
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
					    block * sdp->sd_hash_bsize,
					    sdp->sd_hash_bsize);
		if (error != sdp->sd_hash_bsize) {
			if (error >= 0)
				error = -EIO;
			goto fail;
		}

		from = buf;
		to = (uint64_t *)((char *)buf + sdp->sd_hash_bsize);

		for (x = sdp->sd_hash_ptrs; x--; from++) {
			*to++ = *from;	/*  No endianess worries  */
			*to++ = *from;
		}

1113
		error = gfs2_dir_write_data(dip,
D
David Teigland 已提交
1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
					     (char *)buf + sdp->sd_hash_bsize,
					     block * sdp->sd_sb.sb_bsize,
					     sdp->sd_sb.sb_bsize);
		if (error != sdp->sd_sb.sb_bsize) {
			if (error >= 0)
				error = -EIO;
			goto fail;
		}
	}

	kfree(buf);

	error = gfs2_meta_inode_buffer(dip, &dibh);
	if (!gfs2_assert_withdraw(sdp, !error)) {
		dip->i_di.di_depth++;
		gfs2_dinode_out(&dip->i_di, dibh->b_data);
		brelse(dibh);
	}

	return error;

 fail:
	kfree(buf);

	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)
{
	struct gfs2_dirent *dent_a, *dent_b;
	uint32_t hash_a, hash_b;
	int ret = 0;

	dent_a = *(struct gfs2_dirent **)a;
1159
	hash_a = be32_to_cpu(dent_a->de_hash);
D
David Teigland 已提交
1160 1161

	dent_b = *(struct gfs2_dirent **)b;
1162
	hash_b = be32_to_cpu(dent_b->de_hash);
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1163 1164 1165 1166 1167 1168

	if (hash_a > hash_b)
		ret = 1;
	else if (hash_a < hash_b)
		ret = -1;
	else {
1169 1170
		unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
		unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
D
David Teigland 已提交
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204

		if (len_a > len_b)
			ret = 1;
		else if (len_a < len_b)
			ret = -1;
		else
			ret = memcmp((char *)(dent_a + 1),
				     (char *)(dent_b + 1),
				     len_a);
	}

	return ret;
}

/**
 * do_filldir_main - read out directory entries
 * @dip: The GFS2 inode
 * @offset: The offset in the file to read from
 * @opaque: opaque data to pass to filldir
 * @filldir: The function to pass 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 on exception from filldir
 */

static int do_filldir_main(struct gfs2_inode *dip, uint64_t *offset,
			   void *opaque, gfs2_filldir_t filldir,
1205
			   const struct gfs2_dirent **darr, uint32_t entries,
D
David Teigland 已提交
1206 1207
			   int *copied)
{
1208
	const struct gfs2_dirent *dent, *dent_next;
D
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1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248
	struct gfs2_inum inum;
	uint64_t off, off_next;
	unsigned int x, y;
	int run = 0;
	int error = 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 < *offset)
				continue;
			*offset = off;

			if (off_next == off) {
				if (*copied && !run)
					return 1;
				run = 1;
			} else
				run = 0;
		} else {
			if (off < *offset)
				continue;
			*offset = off;
		}

		gfs2_inum_in(&inum, (char *)&dent->de_inum);

		error = filldir(opaque, (char *)(dent + 1),
1249
				be16_to_cpu(dent->de_name_len),
D
David Teigland 已提交
1250
				off, &inum,
1251
				be16_to_cpu(dent->de_type));
D
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1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
		if (error)
			return 1;

		*copied = 1;
	}

	/* Increment the *offset 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 */

	(*offset)++;

	return 0;
}

1267 1268 1269
static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
			      gfs2_filldir_t filldir, int *copied,
			      unsigned *depth, u64 leaf_no)
D
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1270
{
1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct buffer_head *bh;
	struct gfs2_leaf *lf;
	unsigned entries = 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;
D
David Teigland 已提交
1282 1283

	do {
1284
		error = get_leaf(ip, lfn, &bh);
D
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1285
		if (error)
1286 1287 1288 1289 1290 1291 1292 1293 1294
			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);
D
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1295 1296 1297 1298

	if (!entries)
		return 0;

1299
	error = -ENOMEM;
1300
	larr = vmalloc((leaves + entries) * sizeof(void*));
1301 1302 1303 1304 1305 1306
	if (!larr)
		goto out;
	darr = (const struct gfs2_dirent **)(larr + leaves);
	g.pdent = darr;
	g.offset = 0;
	lfn = leaf_no;
D
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1307

1308 1309
	do {
		error = get_leaf(ip, lfn, &bh);
D
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1310
		if (error)
1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
			goto out_kfree;
		lf = (struct gfs2_leaf *)bh->b_data;
		lfn = be64_to_cpu(lf->lf_next);
		if (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_kfree;
			}
			error = 0;
			larr[leaf++] = bh;
D
David Teigland 已提交
1323
		} else {
1324
			brelse(bh);
D
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1325
		}
1326
	} while(lfn);
D
David Teigland 已提交
1327

1328
	error = do_filldir_main(ip, offset, opaque, filldir, darr,
D
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1329
				entries, copied);
1330 1331 1332
out_kfree:
	for(i = 0; i < leaf; i++)
		brelse(larr[i]);
1333
	vfree(larr);
1334
out:
D
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	return error;
}

/**
1339 1340 1341 1342 1343
 * dir_e_read - Reads the entries from a directory into a filldir buffer
 * @dip: dinode pointer
 * @offset: the hash of the last entry read shifted to the right once
 * @opaque: buffer for the filldir function to fill
 * @filldir: points to the filldir function to use
D
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1344
 *
1345
 * Returns: errno
D
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 */

1348
static int dir_e_read(struct inode *inode, uint64_t *offset, void *opaque,
1349
		      gfs2_filldir_t filldir)
D
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1350
{
1351
	struct gfs2_inode *dip = inode->u.generic_ip;
1352
	struct gfs2_sbd *sdp = dip->i_sbd;
1353
	uint32_t hsize, len = 0;
1354 1355 1356 1357 1358
	uint32_t ht_offset, lp_offset, ht_offset_cur = -1;
	uint32_t hash, index;
	uint64_t *lp;
	int copied = 0;
	int error = 0;
1359
	unsigned depth;
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1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378

	hsize = 1 << dip->i_di.di_depth;
	if (hsize * sizeof(uint64_t) != dip->i_di.di_size) {
		gfs2_consist_inode(dip);
		return -EIO;
	}

	hash = gfs2_dir_offset2hash(*offset);
	index = hash >> (32 - dip->i_di.di_depth);

	lp = kmalloc(sdp->sd_hash_bsize, GFP_KERNEL);
	if (!lp)
		return -ENOMEM;

	while (index < hsize) {
		lp_offset = index & (sdp->sd_hash_ptrs - 1);
		ht_offset = index - lp_offset;

		if (ht_offset_cur != ht_offset) {
1379
			error = gfs2_dir_read_data(dip, (char *)lp,
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						ht_offset * sizeof(uint64_t),
						sdp->sd_hash_bsize);
			if (error != sdp->sd_hash_bsize) {
				if (error >= 0)
					error = -EIO;
				goto out;
			}
			ht_offset_cur = ht_offset;
		}

1390 1391 1392
		error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
					   &copied, &depth,
					   be64_to_cpu(lp[lp_offset]));
D
David Teigland 已提交
1393
		if (error)
1394
			break;
D
David Teigland 已提交
1395

1396
		len = 1 << (dip->i_di.di_depth - depth);
D
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1397 1398 1399
		index = (index & ~(len - 1)) + len;
	}

1400
out:
D
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1401
	kfree(lp);
1402 1403
	if (error > 0)
		error = 0;
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1404 1405 1406
	return error;
}

1407 1408
int gfs2_dir_read(struct inode *inode, uint64_t *offset, void *opaque,
		  gfs2_filldir_t filldir)
D
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1409
{
1410 1411 1412
	struct gfs2_inode *dip = inode->u.generic_ip;
	struct dirent_gather g;
	const struct gfs2_dirent **darr, *dent;
D
David Teigland 已提交
1413 1414 1415 1416
	struct buffer_head *dibh;
	int copied = 0;
	int error;

1417 1418 1419 1420 1421 1422
	if (!dip->i_di.di_entries)
		return 0;

	if (dip->i_di.di_flags & GFS2_DIF_EXHASH)
		return dir_e_read(inode, offset, opaque, filldir);

D
David Teigland 已提交
1423 1424 1425 1426 1427 1428 1429 1430 1431
	if (!gfs2_is_stuffed(dip)) {
		gfs2_consist_inode(dip);
		return -EIO;
	}

	error = gfs2_meta_inode_buffer(dip, &dibh);
	if (error)
		return error;

1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449
	error = -ENOMEM;
	darr = kmalloc(dip->i_di.di_entries * sizeof(struct gfs2_dirent *),
		       GFP_KERNEL);
	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;
		}
		error = do_filldir_main(dip, offset, opaque, filldir, darr,
					dip->i_di.di_entries, &copied);
out:
		kfree(darr);
	}

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1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469
	if (error > 0)
		error = 0;

	brelse(dibh);

	return error;
}

/**
 * gfs2_dir_search - Search a directory
 * @dip: The GFS2 inode
 * @filename:
 * @inode:
 *
 * This routine searches a directory for a file or another directory.
 * Assumes a glock is held on dip.
 *
 * Returns: errno
 */

1470
int gfs2_dir_search(struct inode *dir, const struct qstr *name,
D
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1471 1472
		    struct gfs2_inum *inum, unsigned int *type)
{
1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494
	struct buffer_head *bh;
	struct gfs2_dirent *dent;

	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
	if (dent) {
		if (IS_ERR(dent))
			return PTR_ERR(dent);
		if (inum)
			gfs2_inum_in(inum, (char *)&dent->de_inum);
		if (type)
			*type = be16_to_cpu(dent->de_type);
		brelse(bh);
		return 0;
	}
	return -ENOENT;
}

static int dir_new_leaf(struct inode *inode, const struct qstr *name)
{
	struct buffer_head *bh, *obh;
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct gfs2_leaf *leaf, *oleaf;
D
David Teigland 已提交
1495
	int error;
1496 1497
	u32 index;
	u64 bn;
D
David Teigland 已提交
1498

1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512
	index = name->hash >> (32 - ip->i_di.di_depth);
	error = get_first_leaf(ip, index, &obh);
	if (error)
		return error;
	do {
		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);
D
David Teigland 已提交
1513

1514 1515 1516 1517 1518 1519 1520
	gfs2_trans_add_bh(ip->i_gl, obh, 1);

	leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
	if (!leaf) {
		brelse(obh);
		return -ENOSPC;
	}
1521
	oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
	brelse(bh);
	brelse(obh);

	error = gfs2_meta_inode_buffer(ip, &bh);
	if (error)
		return error;
	gfs2_trans_add_bh(ip->i_gl, bh, 1);
	ip->i_di.di_blocks++;
	gfs2_dinode_out(&ip->i_di, bh->b_data);
	brelse(bh);
	return 0;
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1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
}

/**
 * gfs2_dir_add - Add new filename into directory
 * @dip: The GFS2 inode
 * @filename: The new name
 * @inode: The inode number of the entry
 * @type: The type of the entry
 *
 * Returns: 0 on success, error code on failure
 */

1545 1546
int gfs2_dir_add(struct inode *inode, const struct qstr *name,
		 const struct gfs2_inum *inum, unsigned type)
D
David Teigland 已提交
1547
{
1548 1549 1550 1551
	struct gfs2_inode *ip = inode->u.generic_ip;
	struct buffer_head *bh;
	struct gfs2_dirent *dent;
	struct gfs2_leaf *leaf;
D
David Teigland 已提交
1552 1553
	int error;

1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
	while(1) {
		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(inum, (char *)&dent->de_inum);
			dent->de_type = cpu_to_be16(type);
			if (ip->i_di.di_flags & GFS2_DIF_EXHASH) {
				leaf = (struct gfs2_leaf *)bh->b_data;
				leaf->lf_entries = cpu_to_be16(be16_to_cpu(leaf->lf_entries) + 1);
			}
			brelse(bh);
			error = gfs2_meta_inode_buffer(ip, &bh);
			if (error)
				break;
			gfs2_trans_add_bh(ip->i_gl, bh, 1);
			ip->i_di.di_entries++;
			ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
			gfs2_dinode_out(&ip->i_di, bh->b_data);
			brelse(bh);
			error = 0;
			break;
		}
		if (!(ip->i_di.di_flags & GFS2_DIF_EXHASH)) {
			error = dir_make_exhash(inode);
			if (error)
				break;
			continue;
		}
		error = dir_split_leaf(inode, name);
		if (error == 0)
			continue;
1588
		if (error < 0)
1589 1590 1591 1592 1593 1594
			break;
		if (ip->i_di.di_depth < GFS2_DIR_MAX_DEPTH) {
			error = dir_double_exhash(ip);
			if (error)
				break;
			error = dir_split_leaf(inode, name);
1595
			if (error < 0)
1596
				break;
1597 1598
			if (error == 0)
				continue;
1599 1600 1601 1602 1603 1604 1605
		}
		error = dir_new_leaf(inode, name);
		if (!error)
			continue;
		error = -ENOSPC;
		break;
	}
D
David Teigland 已提交
1606 1607 1608
	return error;
}

1609

D
David Teigland 已提交
1610 1611 1612 1613 1614 1615 1616 1617
/**
 * gfs2_dir_del - Delete a directory entry
 * @dip: The GFS2 inode
 * @filename: The filename
 *
 * Returns: 0 on success, error code on failure
 */

1618
int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
D
David Teigland 已提交
1619
{
1620 1621
	struct gfs2_dirent *dent, *prev = NULL;
	struct buffer_head *bh;
D
David Teigland 已提交
1622 1623
	int error;

1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635
	/* Returns _either_ the entry (if its first in block) or the
	   previous entry otherwise */
	dent = gfs2_dirent_search(dip->i_vnode, 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 */
1636
	if (gfs2_dirent_find(dent, name, NULL) == 0) {
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
		prev = dent;
		dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
	}

	dirent_del(dip, bh, prev, dent);
	if (dip->i_di.di_flags & 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);
	}
1649
	brelse(bh);
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661

	error = gfs2_meta_inode_buffer(dip, &bh);
	if (error)
		return error;

	if (!dip->i_di.di_entries)
		gfs2_consist_inode(dip);
	gfs2_trans_add_bh(dip->i_gl, bh, 1);
	dip->i_di.di_entries--;
	dip->i_di.di_mtime = dip->i_di.di_ctime = get_seconds();
	gfs2_dinode_out(&dip->i_di, bh->b_data);
	brelse(bh);
D
David Teigland 已提交
1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678

	return error;
}

/**
 * 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
 */

1679
int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
D
David Teigland 已提交
1680 1681
		   struct gfs2_inum *inum, unsigned int new_type)
{
1682 1683
	struct buffer_head *bh;
	struct gfs2_dirent *dent;
D
David Teigland 已提交
1684 1685
	int error;

1686 1687 1688 1689 1690 1691 1692
	dent = gfs2_dirent_search(dip->i_vnode, filename, gfs2_dirent_find, &bh);
	if (!dent) {
		gfs2_consist_inode(dip);
		return -EIO;
	}
	if (IS_ERR(dent))
		return PTR_ERR(dent);
D
David Teigland 已提交
1693

1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709
	gfs2_trans_add_bh(dip->i_gl, bh, 1);
	gfs2_inum_out(inum, (char *)&dent->de_inum);
	dent->de_type = cpu_to_be16(new_type);

	if (dip->i_di.di_flags & GFS2_DIF_EXHASH) {
		brelse(bh);
		error = gfs2_meta_inode_buffer(dip, &bh);
		if (error)
			return error;
		gfs2_trans_add_bh(dip->i_gl, bh, 1);
	}

	dip->i_di.di_mtime = dip->i_di.di_ctime = get_seconds();
	gfs2_dinode_out(&dip->i_di, bh->b_data);
	brelse(bh);
	return 0;
D
David Teigland 已提交
1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724
}

/**
 * foreach_leaf - call a function for each leaf in a directory
 * @dip: the directory
 * @lc: the function to call for each each
 * @data: private data to pass to it
 *
 * Returns: errno
 */

static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
{
	struct gfs2_sbd *sdp = dip->i_sbd;
	struct buffer_head *bh;
1725
	struct gfs2_leaf *leaf;
D
David Teigland 已提交
1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747
	uint32_t hsize, len;
	uint32_t ht_offset, lp_offset, ht_offset_cur = -1;
	uint32_t index = 0;
	uint64_t *lp;
	uint64_t leaf_no;
	int error = 0;

	hsize = 1 << dip->i_di.di_depth;
	if (hsize * sizeof(uint64_t) != dip->i_di.di_size) {
		gfs2_consist_inode(dip);
		return -EIO;
	}

	lp = kmalloc(sdp->sd_hash_bsize, GFP_KERNEL);
	if (!lp)
		return -ENOMEM;

	while (index < hsize) {
		lp_offset = index & (sdp->sd_hash_ptrs - 1);
		ht_offset = index - lp_offset;

		if (ht_offset_cur != ht_offset) {
1748
			error = gfs2_dir_read_data(dip, (char *)lp,
D
David Teigland 已提交
1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
						ht_offset * sizeof(uint64_t),
						sdp->sd_hash_bsize);
			if (error != sdp->sd_hash_bsize) {
				if (error >= 0)
					error = -EIO;
				goto out;
			}
			ht_offset_cur = ht_offset;
		}

		leaf_no = be64_to_cpu(lp[lp_offset]);
		if (leaf_no) {
			error = get_leaf(dip, leaf_no, &bh);
			if (error)
				goto out;
1764
			leaf = (struct gfs2_leaf *)bh->b_data;
D
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			brelse(bh);

1767
			len = 1 << (dip->i_di.di_depth - be16_to_cpu(leaf->lf_depth));
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			error = lc(dip, index, len, leaf_no, data);
			if (error)
				goto out;

			index = (index & ~(len - 1)) + len;
		} else
			index++;
	}

	if (index != hsize) {
		gfs2_consist_inode(dip);
		error = -EIO;
	}

 out:
	kfree(lp);

	return error;
}

/**
 * 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
 * @data: not used
 *
 * Returns: errno
 */

static int leaf_dealloc(struct gfs2_inode *dip, uint32_t index, uint32_t len,
			uint64_t leaf_no, void *data)
{
	struct gfs2_sbd *sdp = dip->i_sbd;
1804
	struct gfs2_leaf *tmp_leaf;
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	struct gfs2_rgrp_list rlist;
	struct buffer_head *bh, *dibh;
1807
	uint64_t blk, nblk;
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	unsigned int rg_blocks = 0, l_blocks = 0;
	char *ht;
	unsigned int x, size = len * sizeof(uint64_t);
	int error;

	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));

	ht = kzalloc(size, GFP_KERNEL);
	if (!ht)
		return -ENOMEM;

	gfs2_alloc_get(dip);

	error = gfs2_quota_hold(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
	if (error)
		goto out;

	error = gfs2_rindex_hold(sdp, &dip->i_alloc.al_ri_gh);
	if (error)
		goto out_qs;

	/*  Count the number of leaves  */

1831
	for (blk = leaf_no; blk; blk = nblk) {
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		error = get_leaf(dip, blk, &bh);
		if (error)
			goto out_rlist;
1835 1836
		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
		nblk = be64_to_cpu(tmp_leaf->lf_next);
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		brelse(bh);

		gfs2_rlist_add(sdp, &rlist, blk);
		l_blocks++;
	}

	gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0);

	for (x = 0; x < rlist.rl_rgrps; x++) {
		struct gfs2_rgrpd *rgd;
1847
		rgd = rlist.rl_ghs[x].gh_gl->gl_object;
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		rg_blocks += rgd->rd_ri.ri_length;
	}

	error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
	if (error)
		goto out_rlist;

	error = gfs2_trans_begin(sdp,
1856
			rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
D
David Teigland 已提交
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			RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
	if (error)
		goto out_rg_gunlock;

1861
	for (blk = leaf_no; blk; blk = nblk) {
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		error = get_leaf(dip, blk, &bh);
		if (error)
			goto out_end_trans;
1865 1866
		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
		nblk = be64_to_cpu(tmp_leaf->lf_next);
D
David Teigland 已提交
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		brelse(bh);

		gfs2_free_meta(dip, blk, 1);

		if (!dip->i_di.di_blocks)
			gfs2_consist_inode(dip);
		dip->i_di.di_blocks--;
	}

1876
	error = gfs2_dir_write_data(dip, ht, index * sizeof(uint64_t), size);
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David Teigland 已提交
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886
	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;

1887
	gfs2_trans_add_bh(dip->i_gl, dibh, 1);
D
David Teigland 已提交
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940
	gfs2_dinode_out(&dip->i_di, 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_glock_dq_uninit(&dip->i_alloc.al_ri_gh);

 out_qs:
	gfs2_quota_unhold(dip);

 out:
	gfs2_alloc_put(dip);
	kfree(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 gfs2_sbd *sdp = dip->i_sbd;
	struct buffer_head *bh;
	int error;

	/* Dealloc on-disk leaves to FREEMETA state */
	error = foreach_leaf(dip, leaf_dealloc, NULL);
	if (error)
		return error;

	/* Make this a regular file in case we crash.
	   (We don't want to free these blocks a second time.)  */

	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (error)
		return error;

	error = gfs2_meta_inode_buffer(dip, &bh);
	if (!error) {
1941
		gfs2_trans_add_bh(dip->i_gl, bh, 1);
1942 1943
		((struct gfs2_dinode *)bh->b_data)->di_mode =
						cpu_to_be32(S_IFREG);
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David Teigland 已提交
1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
		brelse(bh);
	}

	gfs2_trans_end(sdp);

	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
 *
1957
 * Returns: 1 if alloc required, 0 if not, -ve on error
D
David Teigland 已提交
1958 1959
 */

1960
int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
D
David Teigland 已提交
1961
{
1962 1963
	struct gfs2_dirent *dent;
	struct buffer_head *bh;
D
David Teigland 已提交
1964

1965
	dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
1966
	if (!dent) {
1967
		return 1;
1968
	}
1969 1970 1971 1972
	if (IS_ERR(dent))
		return PTR_ERR(dent);
	brelse(bh);
	return 0;
D
David Teigland 已提交
1973 1974
}