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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/gfs2/dir.c

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52 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*/
/*
* 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 <linux/bio.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 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))
#define GFS2_HASH_INDEX_MASK 0xffffc000
#define GFS2_USE_HASH_FLAG 0x2000
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, 0, &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(&ip->i_inode);
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;
bool new = false;
if (!size)
return 0;
if (gfs2_is_stuffed(ip) && offset + size <= gfs2_max_stuffed_size(ip))
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);
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) {
extlen = 1;
error = gfs2_alloc_extent(&ip->i_inode, lblock, &dblock,
&extlen, &new);
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(&ip->i_inode);
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;
amount = size - copied;
if (amount > sdp->sd_sb.sb_bsize - o)
amount = sdp->sd_sb.sb_bsize - o;
if (!extlen) {
extlen = 32;
error = gfs2_get_extent(&ip->i_inode, lblock,
&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, 0, &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 = BIT(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);
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;
spin_lock(&ip->i_inode.i_lock);
hc = ip->i_hash_cache;
ip->i_hash_cache = NULL;
spin_unlock(&ip->i_inode.i_lock);
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;
}
/* Look for the dirent that contains the offset specified in data. Once we
* find that dirent, there must be space available there for the new dirent */
static int gfs2_dirent_find_offset(const struct gfs2_dirent *dent,
const struct qstr *name,
void *ptr)
{
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 (ptr < (void *)dent || ptr >= (void *)dent + totlen)
return 0;
if (gfs2_dirent_sentinel(dent))
actual = 0;
if (ptr < (void *)dent + actual)
return -1;
if ((void *)dent + totlen >= ptr + required)
return 1;
return -1;
}
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_sbd *sdp,
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:
fs_warn(sdp, "%s: %s (%s)\n",
__func__, msg, first ? "first in block" : "not first in block");
return -EIO;
}
static int gfs2_dirent_offset(struct gfs2_sbd *sdp, 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:
fs_warn(sdp, "%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(GFS2_SB(inode), 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(GFS2_SB(inode), 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(GFS2_SB(inode), 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);
}
static struct gfs2_dirent *do_init_dirent(struct inode *inode,
struct gfs2_dirent *dent,
const struct qstr *name,
struct buffer_head *bh,
unsigned offset)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_dirent *ndent;
unsigned totlen;
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;
}
/*
* 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)
{
unsigned offset = 0;
if (!gfs2_dirent_sentinel(dent))
offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
return do_init_dirent(inode, dent, name, bh, offset);
}
static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode,
struct buffer_head *bh,
const struct qstr *name,
void *ptr)
{
struct gfs2_dirent *dent;
dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
gfs2_dirent_find_offset, name, ptr);
if (IS_ERR_OR_NULL(dent))
return dent;
return do_init_dirent(inode, dent, name, bh,
(unsigned)(ptr - (void *)dent));
}
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, 0, 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: hash table index of the targeted leaf
* @leaf_out: Resulting leaf block number
*
* Returns: 0 on success, error code otherwise
*/
static int get_leaf_nr(struct gfs2_inode *dip, u32 index, u64 *leaf_out)
{
__be64 *hash;
int error;
hash = gfs2_dir_get_hash_table(dip);
error = PTR_ERR_OR_ZERO(hash);
if (!error)
*leaf_out = be64_to_cpu(*(hash + index));
return error;
}
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 int hsize = BIT(ip->i_depth);
unsigned int 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 (IS_ERR_OR_NULL(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 timespec64 tv = current_time(inode);
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_remove_revoke(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(&empty_name, bh->b_size - sizeof(struct gfs2_leaf), dent);
*pbh = bh;
return leaf;
}
/**
* dir_make_exhash - Convert a stuffed directory into an ExHash directory
* @inode: The directory inode to be converted to exhash
*
* 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 < BIT(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
* @inode: The directory inode to be split
* @name: name of the dirent we're trying to insert
*
* 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;
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 = BIT(dip->i_depth - be16_to_cpu(oleaf->lf_depth));
half_len = len >> 1;
if (!half_len) {
fs_warn(GFS2_SB(inode), "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_array(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;
void *ptr = ((char *)dent - obh->b_data) + nbh->b_data;
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_split_alloc(inode, nbh, &str, ptr);
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;
} 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 = BIT(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_array(hsize_bytes, 2, GFP_NOFS | __GFP_NOWARN);
if (hc2 == NULL)
hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS);
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 = dent_a->de_cookie;
dent_b = *(const struct gfs2_dirent **)b;
hash_b = dent_b->de_cookie;
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
* @sort_start: index of the directory array to start our sort
* @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,
struct gfs2_dirent **darr, u32 entries,
u32 sort_start, int *copied)
{
const struct gfs2_dirent *dent, *dent_next;
u64 off, off_next;
unsigned int x, y;
int run = 0;
if (sort_start < entries)
sort(&darr[sort_start], entries - sort_start,
sizeof(struct gfs2_dirent *), compare_dents, NULL);
dent_next = darr[0];
off_next = dent_next->de_cookie;
for (x = 0, y = 1; x < entries; x++, y++) {
dent = dent_next;
off = off_next;
if (y < entries) {
dent_next = darr[y];
off_next = dent_next->de_cookie;
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);
return ptr;
}
static int gfs2_set_cookies(struct gfs2_sbd *sdp, struct buffer_head *bh,
unsigned leaf_nr, struct gfs2_dirent **darr,
unsigned entries)
{
int sort_id = -1;
int i;
for (i = 0; i < entries; i++) {
unsigned offset;
darr[i]->de_cookie = be32_to_cpu(darr[i]->de_hash);
darr[i]->de_cookie = gfs2_disk_hash2offset(darr[i]->de_cookie);
if (!sdp->sd_args.ar_loccookie)
continue;
offset = (char *)(darr[i]) -
(bh->b_data + gfs2_dirent_offset(sdp, bh->b_data));
offset /= GFS2_MIN_DIRENT_SIZE;
offset += leaf_nr * sdp->sd_max_dents_per_leaf;
if (offset >= GFS2_USE_HASH_FLAG ||
leaf_nr >= GFS2_USE_HASH_FLAG) {
darr[i]->de_cookie |= GFS2_USE_HASH_FLAG;
if (sort_id < 0)
sort_id = i;
continue;
}
darr[i]->de_cookie &= GFS2_HASH_INDEX_MASK;
darr[i]->de_cookie |= offset;
}
return sort_id;
}
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, leaf = 0, offset, sort_offset;
struct gfs2_dirent **darr, *dent;
struct dirent_gather g;
struct buffer_head **larr;
int error, i, need_sort = 0, sort_id;
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 (*depth < GFS2_DIR_MAX_DEPTH || !sdp->sd_args.ar_loccookie) {
need_sort = 1;
sort_offset = 0;
}
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 = (struct gfs2_dirent **)(larr + leaves);
g.pdent = (const struct gfs2_dirent **)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) {
offset = g.offset;
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);
gfs2_consist_inode(ip);
error = -EIO;
goto out_free;
}
error = 0;
sort_id = gfs2_set_cookies(sdp, bh, leaf, &darr[offset],
be16_to_cpu(lf->lf_entries));
if (!need_sort && sort_id >= 0) {
need_sort = 1;
sort_offset = offset + sort_id;
}
larr[leaf++] = bh;
} else {
larr[leaf++] = NULL;
brelse(bh);
}
} while(lfn);
BUG_ON(entries2 != entries);
error = do_filldir_main(ip, ctx, darr, entries, need_sort ?
sort_offset : 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.
* @inode: the directory inode
* @hsize: hash table size
* @index: index into the hash table
* @f_ra: read-ahead parameters
*
* 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(REQ_OP_READ | REQ_RAHEAD | REQ_META |
REQ_PRIO, bh);
continue;
}
brelse(bh);
}
}
/**
* dir_e_read - Reads the entries from a directory into a filldir buffer
* @inode: the directory inode
* @ctx: actor to feed the entries to
* @f_ra: read-ahead parameters
*
* 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 = BIT(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 = BIT(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;
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_array(96, sizeof(struct gfs2_dirent *), GFP_NOFS);
if (darr) {
g.pdent = (const struct gfs2_dirent **)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);
gfs2_consist_inode(dip);
error = -EIO;
goto out;
}
gfs2_set_cookies(sdp, dibh, 0, darr, dip->i_entries);
error = do_filldir_main(dip, ctx, darr,
dip->i_entries, 0, &copied);
out:
kfree(darr);
}
if (error > 0)
error = 0;
brelse(dibh);
return error;
}
/**
* gfs2_dir_search - Search a directory
* @dir: The GFS2 directory 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) {
struct inode *inode;
u16 rahead;
if (IS_ERR(dent))
return ERR_CAST(dent);
dtype = be16_to_cpu(dent->de_type);
rahead = be16_to_cpu(dent->de_rahead);
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);
inode = gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino,
GFS2_BLKST_FREE /* ignore */);
if (!IS_ERR(inode))
GFS2_I(inode)->i_rahead = rahead;
return inode;
}
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 timespec64 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(&ip->i_inode);
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
* @dentry: The directory entry we want to delete
*
* 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 timespec64 tv = current_time(&dip->i_inode);
/* 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 directory inode
* @filename: the filename to be moved
* @nip: the new GFS2 inode
* @new_type: the de_type of the new dirent
*
* 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;
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);
brelse(bh);
dip->i_inode.i_mtime = dip->i_inode.i_ctime = current_time(&dip->i_inode);
mark_inode_dirty_sync(&dip->i_inode);
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);
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, LM_FLAG_NODE_SCOPE);
for (x = 0; x < rlist.rl_rgrps; x++) {
struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl);
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, RES_DINODE +
l_blocks);
if (error)
goto out_rg_gunlock;
bh = leaf_bh;
for (blk = leaf_no; blk; blk = nblk) {
struct gfs2_rgrpd *rgd;
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);
rgd = gfs2_blk2rgrpd(sdp, blk, true);
gfs2_free_meta(dip, rgd, 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 = BIT(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 = BIT(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
* @inode: the directory inode being written to
* @name: 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;
}
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