android_kernel_xiaomi_sm8350/fs/hfsplus/dir.c
Roman Zippel 76b0c26af2 HFS+: fix unlink of links
Some time ago while attempting to handle invalid link counts, I botched
the unlink of links itself, so this patch fixes this now correctly, so
that only the link count of nodes that don't point to links is ignored.
Thanks to Vlado Plaga <rechner@vlado-do.de> to notify me of this
problem.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-10 13:37:51 -07:00

501 lines
12 KiB
C

/*
* linux/fs/hfsplus/dir.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handling of directories
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/random.h>
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
static inline void hfsplus_instantiate(struct dentry *dentry,
struct inode *inode, u32 cnid)
{
dentry->d_fsdata = (void *)(unsigned long)cnid;
d_instantiate(dentry, inode);
}
/* Find the entry inside dir named dentry->d_name */
static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode *inode = NULL;
struct hfs_find_data fd;
struct super_block *sb;
hfsplus_cat_entry entry;
int err;
u32 cnid, linkid = 0;
u16 type;
sb = dir->i_sb;
dentry->d_op = &hfsplus_dentry_operations;
dentry->d_fsdata = NULL;
hfs_find_init(HFSPLUS_SB(sb).cat_tree, &fd);
hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
again:
err = hfs_brec_read(&fd, &entry, sizeof(entry));
if (err) {
if (err == -ENOENT) {
hfs_find_exit(&fd);
/* No such entry */
inode = NULL;
goto out;
}
goto fail;
}
type = be16_to_cpu(entry.type);
if (type == HFSPLUS_FOLDER) {
if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
err = -EIO;
goto fail;
}
cnid = be32_to_cpu(entry.folder.id);
dentry->d_fsdata = (void *)(unsigned long)cnid;
} else if (type == HFSPLUS_FILE) {
if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
err = -EIO;
goto fail;
}
cnid = be32_to_cpu(entry.file.id);
if (entry.file.user_info.fdType == cpu_to_be32(HFSP_HARDLINK_TYPE) &&
entry.file.user_info.fdCreator == cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
(entry.file.create_date == HFSPLUS_I(HFSPLUS_SB(sb).hidden_dir).create_date ||
entry.file.create_date == HFSPLUS_I(sb->s_root->d_inode).create_date) &&
HFSPLUS_SB(sb).hidden_dir) {
struct qstr str;
char name[32];
if (dentry->d_fsdata) {
/*
* We found a link pointing to another link,
* so ignore it and treat it as regular file.
*/
cnid = (unsigned long)dentry->d_fsdata;
linkid = 0;
} else {
dentry->d_fsdata = (void *)(unsigned long)cnid;
linkid = be32_to_cpu(entry.file.permissions.dev);
str.len = sprintf(name, "iNode%d", linkid);
str.name = name;
hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_SB(sb).hidden_dir->i_ino, &str);
goto again;
}
} else if (!dentry->d_fsdata)
dentry->d_fsdata = (void *)(unsigned long)cnid;
} else {
printk(KERN_ERR "hfs: invalid catalog entry type in lookup\n");
err = -EIO;
goto fail;
}
hfs_find_exit(&fd);
inode = hfsplus_iget(dir->i_sb, cnid);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (S_ISREG(inode->i_mode))
HFSPLUS_I(inode).dev = linkid;
out:
d_add(dentry, inode);
return NULL;
fail:
hfs_find_exit(&fd);
return ERR_PTR(err);
}
static int hfsplus_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
int len, err;
char strbuf[HFSPLUS_MAX_STRLEN + 1];
hfsplus_cat_entry entry;
struct hfs_find_data fd;
struct hfsplus_readdir_data *rd;
u16 type;
if (filp->f_pos >= inode->i_size)
return 0;
hfs_find_init(HFSPLUS_SB(sb).cat_tree, &fd);
hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
err = hfs_brec_find(&fd);
if (err)
goto out;
switch ((u32)filp->f_pos) {
case 0:
/* This is completely artificial... */
if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
goto out;
filp->f_pos++;
/* fall through */
case 1:
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
printk(KERN_ERR "hfs: bad catalog folder thread\n");
err = -EIO;
goto out;
}
if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
printk(KERN_ERR "hfs: truncated catalog thread\n");
err = -EIO;
goto out;
}
if (filldir(dirent, "..", 2, 1,
be32_to_cpu(entry.thread.parentID), DT_DIR))
goto out;
filp->f_pos++;
/* fall through */
default:
if (filp->f_pos >= inode->i_size)
goto out;
err = hfs_brec_goto(&fd, filp->f_pos - 1);
if (err)
goto out;
}
for (;;) {
if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
printk(KERN_ERR "hfs: walked past end of dir\n");
err = -EIO;
goto out;
}
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
type = be16_to_cpu(entry.type);
len = HFSPLUS_MAX_STRLEN;
err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
if (err)
goto out;
if (type == HFSPLUS_FOLDER) {
if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
printk(KERN_ERR "hfs: small dir entry\n");
err = -EIO;
goto out;
}
if (HFSPLUS_SB(sb).hidden_dir &&
HFSPLUS_SB(sb).hidden_dir->i_ino == be32_to_cpu(entry.folder.id))
goto next;
if (filldir(dirent, strbuf, len, filp->f_pos,
be32_to_cpu(entry.folder.id), DT_DIR))
break;
} else if (type == HFSPLUS_FILE) {
if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
printk(KERN_ERR "hfs: small file entry\n");
err = -EIO;
goto out;
}
if (filldir(dirent, strbuf, len, filp->f_pos,
be32_to_cpu(entry.file.id), DT_REG))
break;
} else {
printk(KERN_ERR "hfs: bad catalog entry type\n");
err = -EIO;
goto out;
}
next:
filp->f_pos++;
if (filp->f_pos >= inode->i_size)
goto out;
err = hfs_brec_goto(&fd, 1);
if (err)
goto out;
}
rd = filp->private_data;
if (!rd) {
rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
if (!rd) {
err = -ENOMEM;
goto out;
}
filp->private_data = rd;
rd->file = filp;
list_add(&rd->list, &HFSPLUS_I(inode).open_dir_list);
}
memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
out:
hfs_find_exit(&fd);
return err;
}
static int hfsplus_dir_release(struct inode *inode, struct file *file)
{
struct hfsplus_readdir_data *rd = file->private_data;
if (rd) {
list_del(&rd->list);
kfree(rd);
}
return 0;
}
static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct inode *inode;
int res;
inode = hfsplus_new_inode(dir->i_sb, mode);
if (!inode)
return -ENOSPC;
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res) {
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
return res;
}
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
return 0;
}
static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
struct dentry *dst_dentry)
{
struct super_block *sb = dst_dir->i_sb;
struct inode *inode = src_dentry->d_inode;
struct inode *src_dir = src_dentry->d_parent->d_inode;
struct qstr str;
char name[32];
u32 cnid, id;
int res;
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
for (;;) {
get_random_bytes(&id, sizeof(cnid));
id &= 0x3fffffff;
str.name = name;
str.len = sprintf(name, "iNode%d", id);
res = hfsplus_rename_cat(inode->i_ino,
src_dir, &src_dentry->d_name,
HFSPLUS_SB(sb).hidden_dir, &str);
if (!res)
break;
if (res != -EEXIST)
return res;
}
HFSPLUS_I(inode).dev = id;
cnid = HFSPLUS_SB(sb).next_cnid++;
src_dentry->d_fsdata = (void *)(unsigned long)cnid;
res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode);
if (res)
/* panic? */
return res;
HFSPLUS_SB(sb).file_count++;
}
cnid = HFSPLUS_SB(sb).next_cnid++;
res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
if (res)
return res;
inc_nlink(inode);
hfsplus_instantiate(dst_dentry, inode, cnid);
atomic_inc(&inode->i_count);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
HFSPLUS_SB(sb).file_count++;
sb->s_dirt = 1;
return 0;
}
static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = dentry->d_inode;
struct qstr str;
char name[32];
u32 cnid;
int res;
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
cnid = (u32)(unsigned long)dentry->d_fsdata;
if (inode->i_ino == cnid &&
atomic_read(&HFSPLUS_I(inode).opencnt)) {
str.name = name;
str.len = sprintf(name, "temp%lu", inode->i_ino);
res = hfsplus_rename_cat(inode->i_ino,
dir, &dentry->d_name,
HFSPLUS_SB(sb).hidden_dir, &str);
if (!res)
inode->i_flags |= S_DEAD;
return res;
}
res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
if (res)
return res;
if (inode->i_nlink > 0)
drop_nlink(inode);
if (inode->i_ino == cnid)
clear_nlink(inode);
if (!inode->i_nlink) {
if (inode->i_ino != cnid) {
HFSPLUS_SB(sb).file_count--;
if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {
res = hfsplus_delete_cat(inode->i_ino,
HFSPLUS_SB(sb).hidden_dir,
NULL);
if (!res)
hfsplus_delete_inode(inode);
} else
inode->i_flags |= S_DEAD;
} else
hfsplus_delete_inode(inode);
} else
HFSPLUS_SB(sb).file_count--;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return res;
}
static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode;
int res;
inode = hfsplus_new_inode(dir->i_sb, S_IFDIR | mode);
if (!inode)
return -ENOSPC;
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res) {
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
return res;
}
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
return 0;
}
static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode;
int res;
inode = dentry->d_inode;
if (inode->i_size != 2)
return -ENOTEMPTY;
res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
if (res)
return res;
clear_nlink(inode);
inode->i_ctime = CURRENT_TIME_SEC;
hfsplus_delete_inode(inode);
mark_inode_dirty(inode);
return 0;
}
static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct super_block *sb;
struct inode *inode;
int res;
sb = dir->i_sb;
inode = hfsplus_new_inode(sb, S_IFLNK | S_IRWXUGO);
if (!inode)
return -ENOSPC;
res = page_symlink(inode, symname, strlen(symname) + 1);
if (res) {
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
return res;
}
mark_inode_dirty(inode);
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (!res) {
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
}
return res;
}
static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t rdev)
{
struct super_block *sb;
struct inode *inode;
int res;
sb = dir->i_sb;
inode = hfsplus_new_inode(sb, mode);
if (!inode)
return -ENOSPC;
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res) {
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
return res;
}
init_special_inode(inode, mode, rdev);
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
return 0;
}
static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int res;
/* Unlink destination if it already exists */
if (new_dentry->d_inode) {
res = hfsplus_unlink(new_dir, new_dentry);
if (res)
return res;
}
res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
old_dir, &old_dentry->d_name,
new_dir, &new_dentry->d_name);
if (!res)
new_dentry->d_fsdata = old_dentry->d_fsdata;
return res;
}
const struct inode_operations hfsplus_dir_inode_operations = {
.lookup = hfsplus_lookup,
.create = hfsplus_create,
.link = hfsplus_link,
.unlink = hfsplus_unlink,
.mkdir = hfsplus_mkdir,
.rmdir = hfsplus_rmdir,
.symlink = hfsplus_symlink,
.mknod = hfsplus_mknod,
.rename = hfsplus_rename,
};
const struct file_operations hfsplus_dir_operations = {
.read = generic_read_dir,
.readdir = hfsplus_readdir,
.ioctl = hfsplus_ioctl,
.llseek = generic_file_llseek,
.release = hfsplus_dir_release,
};