android_kernel_samsung_msm8976/fs/ocfs2/dir.c
Joel Becker 2b388c6790 ocfs2: Compile-time disabling of ocfs2 debugging output.
Give gcc the chance to compile out the debug logging code in ocfs2.
This saves some size at the expense of being able to debug the code.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-29 14:48:30 -07:00

614 lines
15 KiB
C

/* -*- 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;
}