/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
- * Copyright (C) 2004-2005 Red Hat, Inc. 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
*/
/*
-* 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.
-*/
+ * 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.
+ */
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
-#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/sort.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/vmalloc.h>
-#include <asm/semaphore.h>
#include "gfs2.h"
#include "lm_interface.h"
uint32_t index, uint32_t len, uint64_t leaf_no,
void *data);
-int gfs2_dir_get_buffer(struct gfs2_inode *ip, uint64_t block, int new,
- struct buffer_head **bhp)
+
+int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, uint64_t block,
+ struct buffer_head **bhp)
{
struct buffer_head *bh;
- int error = 0;
-
- if (new) {
- 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));
- } else {
- 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;
- }
- }
+ 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, uint64_t block,
+ struct buffer_head **bhp)
+{
+ struct buffer_head *bh;
+ int error;
+ 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;
+}
static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
unsigned int offset, unsigned int size)
if (!extlen) {
new = 1;
- error = gfs2_block_map(ip, lblock, &new, &dblock,
- &extlen);
+ error = gfs2_extent_map(ip->i_vnode, lblock, &new,
+ &dblock, &extlen);
if (error)
goto fail;
error = -EIO;
goto fail;
}
- error = gfs2_dir_get_buffer(ip, dblock,
- (amount == sdp->sd_jbsize) ?
- 1 : new, &bh);
+ 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;
if (!extlen) {
new = 0;
- error = gfs2_block_map(ip, lblock, &new, &dblock,
- &extlen);
+ error = gfs2_extent_map(ip->i_vnode, lblock, &new,
+ &dblock, &extlen);
if (error)
goto fail;
}
gfs2_meta_ra(ip->i_gl, dblock, extlen);
if (dblock) {
- error = gfs2_dir_get_buffer(ip, dblock, new, &bh);
+ if (new)
+ error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
+ else
+ error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
if (error)
goto fail;
dblock++;
* Takes a dent from which to grab space as an argument. Returns the
* newly created dent.
*/
-struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
- struct gfs2_dirent *dent,
- const struct qstr *name,
- struct buffer_head *bh)
+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 = inode->u.generic_ip;
struct gfs2_dirent *ndent;
projects / powerpc.git / blobdiff