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dir.c
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dir.c
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/*
* 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.
*/
#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 gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
#define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
typedef int (*leaf_call_t) (struct gfs2_inode *dip, u32 index, u32 len,
u64 leaf_no, void *data);
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_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));
*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_bh(ip->i_gl, dibh, 1);
memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
if (ip->i_disksize < offset + size)
ip->i_disksize = 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_bh(ip->i_gl, bh, 1);
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_disksize < offset + copied)
ip->i_disksize = offset + copied;
ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
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, char *buf,
u64 offset, unsigned int size)
{
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, u64 offset,
unsigned int size, unsigned ra)
{
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 (offset >= ip->i_disksize)
return 0;
if (offset + size > ip->i_disksize)
size = ip->i_disksize - offset;
if (!size)
return 0;
if (gfs2_is_stuffed(ip))
return gfs2_dir_read_stuffed(ip, buf, offset, size);
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;
error = gfs2_extent_map(&ip->i_inode, lblock, &new,
&dblock, &extlen);
if (error || !dblock)
goto fail;
BUG_ON(extlen < 1);
if (!ra)
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;
copied += amount;
lblock++;
o = sizeof(struct gfs2_meta_header);
}
return copied;
fail:
return (copied) ? copied : error;
}
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 = GFS2_DIRENT_SIZE(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:
printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", 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:
printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
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);
}
/**
* 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;
if (be32_to_cpu(h->mh_type) == GFS2_METATYPE_LF) {
if (gfs2_meta_check(GFS2_SB(&dip->i_inode), bh))
return -EIO;
*dent = (struct gfs2_dirent *)(bh->b_data +
sizeof(struct gfs2_leaf));
return IS_LEAF;
} else {
if (gfs2_metatype_check(GFS2_SB(&dip->i_inode), bh, GFS2_METATYPE_DI))
return -EIO;
*dent = (struct gfs2_dirent *)(bh->b_data +
sizeof(struct gfs2_dinode));
return IS_DINODE;
}
}
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_bh(dip->i_gl, bh, 1);
/* 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_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;
}
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)) {
/* printk(KERN_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 leaf_no;
int error;
error = gfs2_dir_read_data(dip, (char *)&leaf_no,
index * sizeof(__be64),
sizeof(__be64), 0);
if (error != sizeof(u64))
return (error < 0) ? error : -EIO;
*leaf_out = be64_to_cpu(leaf_no);
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) != ip->i_disksize) {
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 = "", .len = 0, .hash = 0 };
error = gfs2_alloc_block(ip, &bn, &n);
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_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 = 0;
leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
leaf->lf_next = 0;
memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
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_bh(dip->i_gl, dibh, 1);
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);
dip->i_disksize = 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_bh(dip->i_gl, obh, 1);
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) {
printk(KERN_WARNING "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 | __GFP_NOFAIL);
/* Change the pointers */
for (x = 0; x < half_len; x++)
lp[x] = cpu_to_be64(bn);
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;