/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dir.c
*
* Creates, reads, walks and deletes directory-nodes
*
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
*
* Portions of this code from linux/fs/ext3/dir.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/dir.c
*
* Copyright (C) 1991, 1992 Linux Torvalds
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#define MLOG_MASK_PREFIX ML_NAMEI
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dir.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "namei.h"
#include "suballoc.h"
#include "uptodate.h"
#include "buffer_head_io.h"
static unsigned char ocfs2_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};
static int ocfs2_extend_dir(struct ocfs2_super *osb,
struct inode *dir,
struct buffer_head *parent_fe_bh,
struct buffer_head **new_de_bh);
/*
* ocfs2_readdir()
*
*/
int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
int error = 0;
unsigned long offset, blk;
int i, num, stored;
struct buffer_head * bh, * tmp;
struct ocfs2_dir_entry * de;
int err;
struct inode *inode = filp->f_dentry->d_inode;
struct super_block * sb = inode->i_sb;
int have_disk_lock = 0;
mlog_entry("dirino=%llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
stored = 0;
bh = NULL;
error = ocfs2_meta_lock(inode, NULL, NULL, 0);
if (error < 0) {
if (error != -ENOENT)
mlog_errno(error);
/* we haven't got any yet, so propagate the error. */
stored = error;
goto bail;
}
have_disk_lock = 1;
offset = filp->f_pos & (sb->s_blocksize - 1);
while (!error && !stored && filp->f_pos < i_size_read(inode)) {
blk = (filp->f_pos) >> sb->s_blocksize_bits;
bh = ocfs2_bread(inode, blk, &err, 0);
if (!bh) {
mlog(ML_ERROR,
"directory #%llu contains a hole at offset %lld\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
filp->f_pos);
filp->f_pos += sb->s_blocksize - offset;
continue;
}
/*
* Do the readahead (8k)
*/
if (!offset) {
for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0;
i > 0; i--) {
tmp = ocfs2_bread(inode, ++blk, &err, 1);
if (tmp)
brelse(tmp);
}
}
revalidate:
/* If the dir block has changed since the last call to
* readdir(2), then we might be pointing to an invalid
* dirent right now. Scan from the start of the block
* to make sure. */
if (filp->f_version != inode->i_version) {
for (i = 0; i < sb->s_blocksize && i < offset; ) {
de = (struct ocfs2_dir_entry *) (bh->b_data + i);
/* It's too expensive to do a full
* dirent test each time round this
* loop, but we do have to test at
* least that it is non-zero. A
* failure will be detected in the
* dirent test below. */
if (le16_to_cpu(de->rec_len) <
OCFS2_DIR_REC_LEN(1))
break;
i += le16_to_cpu(de->rec_len);
}
offset = i;
filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
| offset;
filp->f_version = inode->i_version;
}
while (!error && filp->f_pos < i_size_read(inode)
&& offset < sb->s_blocksize) {
de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
/* On error, skip the f_pos to the
next block. */
filp->f_pos = (filp->f_pos |
(sb->s_blocksize - 1)) + 1;
brelse(bh);
goto bail;
}
offset += le16_to_cpu(de->rec_len);
if (le64_to_cpu(de->inode)) {
/* We might block in the next section
* if the data destination is
* currently swapped out. So, use a
* version stamp to detect whether or
* not the directory has been modified
* during the copy operation.
*/
unsigned long version = filp->f_version;
unsigned char d_type = DT_UNKNOWN;
if (de->file_type < OCFS2_FT_MAX)
d_type = ocfs2_filetype_table[de->file_type];
error = filldir(dirent, de->name,
de->name_len,
filp->f_pos,
ino_from_blkno(sb, le64_to_cpu(de->inode)),
d_type);
if (error)
break;
if (version != filp->f_version)
goto revalidate;
stored ++;
}
filp->f_pos += le16_to_cpu(de->rec_len);
}
offset = 0;
brelse(bh);
}
stored = 0;
bail:
if (have_disk_lock)
ocfs2_meta_unlock(inode, 0);
mlog_exit(stored);
return stored;
}
/*
* NOTE: this should always be called with parent dir i_mutex taken.
*/
int ocfs2_find_files_on_disk(const char *name,
int namelen,
u64 *blkno,
struct inode *inode,
struct buffer_head **dirent_bh,
struct ocfs2_dir_entry **dirent)
{
int status = -ENOENT;
mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n",
namelen, name, blkno, inode, dirent_bh, dirent);
*dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent);
if (!*dirent_bh || !*dirent) {
status = -ENOENT;
goto leave;
}
*blkno = le64_to_cpu((*dirent)->inode);
status = 0;
leave:
if (status < 0) {
*dirent = NULL;
if (*dirent_bh) {
brelse(*dirent_bh);
*dirent_bh = NULL;
}
}
mlog_exit(status);
return status;
}
/* Check for a name within a directory.
*
* Return 0 if the name does not exist
* Return -EEXIST if the directory contains the name
*
* Callers should have i_mutex + a cluster lock on dir
*/
int ocfs2_check_dir_for_entry(struct inode *dir,
const char *name,
int namelen)
{
int ret;
struct buffer_head *dirent_bh = NULL;
struct ocfs2_dir_entry *dirent = NULL;
mlog_entry("dir %llu, name '%.*s'\n",
(unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);
ret = -EEXIST;
dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent);
if (dirent_bh)
goto bail;
ret = 0;
bail:
if (dirent_bh)
brelse(dirent_bh);
mlog_exit(ret);
return ret;
}
/*
* routine to check that the specified directory is empty (for rmdir)
*/
int ocfs2_empty_dir(struct inode *inode)
{
unsigned long offset;
struct buffer_head * bh;
struct ocfs2_dir_entry * de, * de1;
struct super_block * sb;
int err;
sb = inode->i_sb;
if ((i_size_read(inode) <
(OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) ||
!(bh = ocfs2_bread(inode, 0, &err, 0))) {
mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
return 1;
}
de = (struct ocfs2_dir_entry *) bh->b_data;
de1 = (struct ocfs2_dir_entry *)
((char *)de + le16_to_cpu(de->rec_len));
if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) ||
!le64_to_cpu(de1->inode) ||
strcmp(".", de->name) ||
strcmp("..", de1->name)) {
mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
brelse(bh);
return 1;
}
offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len));
while (offset < i_size_read(inode) ) {
if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) {
brelse(bh);
bh = ocfs2_bread(inode,
offset >> sb->s_blocksize_bits, &err, 0);
if (!bh) {
mlog(ML_ERROR, "dir %llu has a hole at %lu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, offset);
offset += sb->s_blocksize;
continue;
}
de = (struct ocfs2_dir_entry *) bh->b_data;
}
if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
brelse(bh);
return 1;
}
if (le64_to_cpu(de->inode)) {
brelse(bh);
return 0;
}
offset += le16_to_cpu(de->rec_len);
de = (struct ocfs2_dir_entry *)
((char *)de + le16_to_cpu(de->rec_len));
}
brelse(bh);
return 1;
}
/* returns a bh of the 1st new block in the allocation. */
int ocfs2_do_extend_dir(struct super_block *sb,
struct ocfs2_journal_handle *handle,
struct inode *dir,
struct buffer_head *parent_fe_bh,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct buffer_head **new_bh)
{
int status;
int extend;
u64 p_blkno;
spin_lock(&OCFS2_I(dir)->ip_lock);
extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
spin_unlock(&OCFS2_I(dir)->ip_lock);
if (extend) {
status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1,
parent_fe_bh, handle,
data_ac, meta_ac, NULL);
BUG_ON(status == -EAGAIN);
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >>
(sb->s_blocksize_bits - 9)),
1, &p_blkno, NULL);
if (status < 0) {
mlog_errno(status);
goto bail;
}
*new_bh = sb_getblk(sb, p_blkno);
if (!*new_bh) {
status = -EIO;
mlog_errno(status);
goto bail;
}
status = 0;
bail:
mlog_exit(status);
return status;
}
/* assumes you already have a cluster lock on the directory. */
static int ocfs2_extend_dir(struct ocfs2_super *osb,
struct inode *dir,
struct buffer_head *parent_fe_bh,
struct buffer_head **new_de_bh)
{
int status = 0;
int credits, num_free_extents;
loff_t dir_i_size;
struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
struct ocfs2_alloc_context *data_ac = NULL;
struct ocfs2_alloc_context *meta_ac = NULL;
struct ocfs2_journal_handle *handle = NULL;
struct buffer_head *new_bh = NULL;
struct ocfs2_dir_entry * de;
struct super_block *sb = osb->sb;
mlog_entry_void();
dir_i_size = i_size_read(dir);
mlog(0, "extending dir %llu (i_size = %lld)\n",
(unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size);
handle = ocfs2_alloc_handle(osb);
if (handle == NULL) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
/* dir->i_size is always block aligned. */
spin_lock(&OCFS2_I(dir)->ip_lock);
if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
spin_unlock(&OCFS2_I(dir)->ip_lock);
num_free_extents = ocfs2_num_free_extents(osb, dir, fe);
if (num_free_extents < 0) {
status = num_free_extents;
mlog_errno(status);
goto bail;
}
if (!num_free_extents) {
status = ocfs2_reserve_new_metadata(osb, handle,
fe, &meta_ac);
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
}
status = ocfs2_reserve_clusters(osb, handle, 1, &data_ac);
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
goto bail;
}
credits = ocfs2_calc_extend_credits(sb, fe, 1);
} else {
spin_unlock(&OCFS2_I(dir)->ip_lock);
credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
}
handle = ocfs2_start_trans(osb, handle, credits);
if (IS_ERR(handle)) {
status = PTR_ERR(handle);
handle = NULL;
mlog_errno(status);
goto bail;
}
status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
data_ac, meta_ac, &new_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
ocfs2_set_new_buffer_uptodate(dir, new_bh);
status = ocfs2_journal_access(handle, dir, new_bh,
OCFS2_JOURNAL_ACCESS_CREATE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
memset(new_bh->b_data, 0, sb->s_blocksize);
de = (struct ocfs2_dir_entry *) new_bh->b_data;
de->inode = 0;
de->rec_len = cpu_to_le16(sb->s_blocksize);
status = ocfs2_journal_dirty(handle, new_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
dir_i_size += dir->i_sb->s_blocksize;
i_size_write(dir, dir_i_size);
dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size);
status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
*new_de_bh = new_bh;
get_bh(*new_de_bh);
bail:
if (handle)
ocfs2_commit_trans(handle);
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
if (new_bh)
brelse(new_bh);
mlog_exit(status);
return status;
}
/*
* Search the dir for a good spot, extending it if necessary. The
* block containing an appropriate record is returned in ret_de_bh.
*/
int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
struct inode *dir,
struct buffer_head *parent_fe_bh,
const char *name,
int namelen,
struct buffer_head **ret_de_bh)
{
unsigned long offset;
struct buffer_head * bh = NULL;
unsigned short rec_len;
struct ocfs2_dinode *fe;
struct ocfs2_dir_entry *de;
struct super_block *sb;
int status;
mlog_entry_void();
mlog(0, "getting ready to insert namelen %d into dir %llu\n",
namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno);
BUG_ON(!S_ISDIR(dir->i_mode));
fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir));
sb = dir->i_sb;
if (!namelen) {
status = -EINVAL;
mlog_errno(status);
goto bail;
}
bh = ocfs2_bread(dir, 0, &status, 0);
if (!bh) {
mlog_errno(status);
goto bail;
}
rec_len = OCFS2_DIR_REC_LEN(namelen);
offset = 0;
de = (struct ocfs2_dir_entry *) bh->b_data;
while (1) {
if ((char *)de >= sb->s_blocksize + bh->b_data) {
brelse(bh);
bh = NULL;
if (i_size_read(dir) <= offset) {
status = ocfs2_extend_dir(osb,
dir,
parent_fe_bh,
&bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
BUG_ON(!bh);
*ret_de_bh = bh;
get_bh(*ret_de_bh);
goto bail;
}
bh = ocfs2_bread(dir,
offset >> sb->s_blocksize_bits,
&status,
0);
if (!bh) {
mlog_errno(status);
goto bail;
}
/* move to next block */
de = (struct ocfs2_dir_entry *) bh->b_data;
}
if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
status = -ENOENT;
goto bail;
}
if (ocfs2_match(namelen, name, de)) {
status = -EEXIST;
goto bail;
}
if (((le64_to_cpu(de->inode) == 0) &&
(le16_to_cpu(de->rec_len) >= rec_len)) ||
(le16_to_cpu(de->rec_len) >=
(OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) {
/* Ok, we found a spot. Return this bh and let
* the caller actually fill it in. */
*ret_de_bh = bh;
get_bh(*ret_de_bh);
status = 0;
goto bail;
}
offset += le16_to_cpu(de->rec_len);
de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
}
status = 0;
bail:
if (bh)
brelse(bh);
mlog_exit(status);
return status;
}
