linux-stable/fs/hfsplus/catalog.c
Christoph Hellwig f6089ff87d hfsplus: fix link corruption
HFS implements hardlink by using indirect catalog entries that refer to a hidden
directly.  The link target is cached in the dev field in the HFS+ specific
inode, which is also used for the device number for device files, and inside
for passing the nlink value of the indirect node from hfsplus_cat_write_inode
to a helper function.  Now if we happen to write out the indirect node while
hfsplus_link is creating the catalog entry we'll get a link pointing to the
linkid of the current nlink value.  This can easily be reproduced by a large
enough loop of local git-clone operations.

Stop abusing the dev field in the HFS+ inode for short term storage by
refactoring the way the permission structure in the catalog entry is
set up, and rename the dev field to linkid to avoid any confusion.

While we're at it also prevent creating hard links to special files, as
the HFS+ dev and linkid share the same space in the on-disk structure.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
2010-10-14 09:54:28 -04:00

387 lines
10 KiB
C

/*
* linux/fs/hfsplus/catalog.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handling of catalog records
*/
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
int hfsplus_cat_case_cmp_key(const hfsplus_btree_key *k1,
const hfsplus_btree_key *k2)
{
__be32 k1p, k2p;
k1p = k1->cat.parent;
k2p = k2->cat.parent;
if (k1p != k2p)
return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
return hfsplus_strcasecmp(&k1->cat.name, &k2->cat.name);
}
int hfsplus_cat_bin_cmp_key(const hfsplus_btree_key *k1,
const hfsplus_btree_key *k2)
{
__be32 k1p, k2p;
k1p = k1->cat.parent;
k2p = k2->cat.parent;
if (k1p != k2p)
return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
return hfsplus_strcmp(&k1->cat.name, &k2->cat.name);
}
void hfsplus_cat_build_key(struct super_block *sb, hfsplus_btree_key *key,
u32 parent, struct qstr *str)
{
int len;
key->cat.parent = cpu_to_be32(parent);
if (str) {
hfsplus_asc2uni(sb, &key->cat.name, str->name, str->len);
len = be16_to_cpu(key->cat.name.length);
} else {
key->cat.name.length = 0;
len = 0;
}
key->key_len = cpu_to_be16(6 + 2 * len);
}
static void hfsplus_cat_build_key_uni(hfsplus_btree_key *key, u32 parent,
struct hfsplus_unistr *name)
{
int ustrlen;
ustrlen = be16_to_cpu(name->length);
key->cat.parent = cpu_to_be32(parent);
key->cat.name.length = cpu_to_be16(ustrlen);
ustrlen *= 2;
memcpy(key->cat.name.unicode, name->unicode, ustrlen);
key->key_len = cpu_to_be16(6 + ustrlen);
}
static void hfsplus_set_perms(struct inode *inode, struct hfsplus_perm *perms)
{
if (inode->i_flags & S_IMMUTABLE)
perms->rootflags |= HFSPLUS_FLG_IMMUTABLE;
else
perms->rootflags &= ~HFSPLUS_FLG_IMMUTABLE;
if (inode->i_flags & S_APPEND)
perms->rootflags |= HFSPLUS_FLG_APPEND;
else
perms->rootflags &= ~HFSPLUS_FLG_APPEND;
HFSPLUS_I(inode)->rootflags = perms->rootflags;
HFSPLUS_I(inode)->userflags = perms->userflags;
perms->mode = cpu_to_be16(inode->i_mode);
perms->owner = cpu_to_be32(inode->i_uid);
perms->group = cpu_to_be32(inode->i_gid);
}
static int hfsplus_cat_build_record(hfsplus_cat_entry *entry, u32 cnid, struct inode *inode)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
if (S_ISDIR(inode->i_mode)) {
struct hfsplus_cat_folder *folder;
folder = &entry->folder;
memset(folder, 0, sizeof(*folder));
folder->type = cpu_to_be16(HFSPLUS_FOLDER);
folder->id = cpu_to_be32(inode->i_ino);
HFSPLUS_I(inode)->create_date =
folder->create_date =
folder->content_mod_date =
folder->attribute_mod_date =
folder->access_date = hfsp_now2mt();
hfsplus_set_perms(inode, &folder->permissions);
if (inode == sbi->hidden_dir)
/* invisible and namelocked */
folder->user_info.frFlags = cpu_to_be16(0x5000);
return sizeof(*folder);
} else {
struct hfsplus_cat_file *file;
file = &entry->file;
memset(file, 0, sizeof(*file));
file->type = cpu_to_be16(HFSPLUS_FILE);
file->flags = cpu_to_be16(HFSPLUS_FILE_THREAD_EXISTS);
file->id = cpu_to_be32(cnid);
HFSPLUS_I(inode)->create_date =
file->create_date =
file->content_mod_date =
file->attribute_mod_date =
file->access_date = hfsp_now2mt();
if (cnid == inode->i_ino) {
hfsplus_set_perms(inode, &file->permissions);
if (S_ISLNK(inode->i_mode)) {
file->user_info.fdType = cpu_to_be32(HFSP_SYMLINK_TYPE);
file->user_info.fdCreator = cpu_to_be32(HFSP_SYMLINK_CREATOR);
} else {
file->user_info.fdType = cpu_to_be32(sbi->type);
file->user_info.fdCreator = cpu_to_be32(sbi->creator);
}
if ((file->permissions.rootflags | file->permissions.userflags) & HFSPLUS_FLG_IMMUTABLE)
file->flags |= cpu_to_be16(HFSPLUS_FILE_LOCKED);
} else {
file->user_info.fdType = cpu_to_be32(HFSP_HARDLINK_TYPE);
file->user_info.fdCreator = cpu_to_be32(HFSP_HFSPLUS_CREATOR);
file->user_info.fdFlags = cpu_to_be16(0x100);
file->create_date = HFSPLUS_I(sbi->hidden_dir)->create_date;
file->permissions.dev = cpu_to_be32(HFSPLUS_I(inode)->linkid);
}
return sizeof(*file);
}
}
static int hfsplus_fill_cat_thread(struct super_block *sb,
hfsplus_cat_entry *entry, int type,
u32 parentid, struct qstr *str)
{
entry->type = cpu_to_be16(type);
entry->thread.reserved = 0;
entry->thread.parentID = cpu_to_be32(parentid);
hfsplus_asc2uni(sb, &entry->thread.nodeName, str->name, str->len);
return 10 + be16_to_cpu(entry->thread.nodeName.length) * 2;
}
/* Try to get a catalog entry for given catalog id */
int hfsplus_find_cat(struct super_block *sb, u32 cnid,
struct hfs_find_data *fd)
{
hfsplus_cat_entry tmp;
int err;
u16 type;
hfsplus_cat_build_key(sb, fd->search_key, cnid, NULL);
err = hfs_brec_read(fd, &tmp, sizeof(hfsplus_cat_entry));
if (err)
return err;
type = be16_to_cpu(tmp.type);
if (type != HFSPLUS_FOLDER_THREAD && type != HFSPLUS_FILE_THREAD) {
printk(KERN_ERR "hfs: found bad thread record in catalog\n");
return -EIO;
}
if (be16_to_cpu(tmp.thread.nodeName.length) > 255) {
printk(KERN_ERR "hfs: catalog name length corrupted\n");
return -EIO;
}
hfsplus_cat_build_key_uni(fd->search_key, be32_to_cpu(tmp.thread.parentID),
&tmp.thread.nodeName);
return hfs_brec_find(fd);
}
int hfsplus_create_cat(u32 cnid, struct inode *dir, struct qstr *str, struct inode *inode)
{
struct super_block *sb = dir->i_sb;
struct hfs_find_data fd;
hfsplus_cat_entry entry;
int entry_size;
int err;
dprint(DBG_CAT_MOD, "create_cat: %s,%u(%d)\n", str->name, cnid, inode->i_nlink);
hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
hfsplus_cat_build_key(sb, fd.search_key, cnid, NULL);
entry_size = hfsplus_fill_cat_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
HFSPLUS_FOLDER_THREAD : HFSPLUS_FILE_THREAD,
dir->i_ino, str);
err = hfs_brec_find(&fd);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto err2;
}
err = hfs_brec_insert(&fd, &entry, entry_size);
if (err)
goto err2;
hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, str);
entry_size = hfsplus_cat_build_record(&entry, cnid, inode);
err = hfs_brec_find(&fd);
if (err != -ENOENT) {
/* panic? */
if (!err)
err = -EEXIST;
goto err1;
}
err = hfs_brec_insert(&fd, &entry, entry_size);
if (err)
goto err1;
dir->i_size++;
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
hfs_find_exit(&fd);
return 0;
err1:
hfsplus_cat_build_key(sb, fd.search_key, cnid, NULL);
if (!hfs_brec_find(&fd))
hfs_brec_remove(&fd);
err2:
hfs_find_exit(&fd);
return err;
}
int hfsplus_delete_cat(u32 cnid, struct inode *dir, struct qstr *str)
{
struct super_block *sb = dir->i_sb;
struct hfs_find_data fd;
struct hfsplus_fork_raw fork;
struct list_head *pos;
int err, off;
u16 type;
dprint(DBG_CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
if (!str) {
int len;
hfsplus_cat_build_key(sb, fd.search_key, cnid, NULL);
err = hfs_brec_find(&fd);
if (err)
goto out;
off = fd.entryoffset + offsetof(struct hfsplus_cat_thread, nodeName);
fd.search_key->cat.parent = cpu_to_be32(dir->i_ino);
hfs_bnode_read(fd.bnode, &fd.search_key->cat.name.length, off, 2);
len = be16_to_cpu(fd.search_key->cat.name.length) * 2;
hfs_bnode_read(fd.bnode, &fd.search_key->cat.name.unicode, off + 2, len);
fd.search_key->key_len = cpu_to_be16(6 + len);
} else
hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, str);
err = hfs_brec_find(&fd);
if (err)
goto out;
type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
if (type == HFSPLUS_FILE) {
#if 0
off = fd.entryoffset + offsetof(hfsplus_cat_file, data_fork);
hfs_bnode_read(fd.bnode, &fork, off, sizeof(fork));
hfsplus_free_fork(sb, cnid, &fork, HFSPLUS_TYPE_DATA);
#endif
off = fd.entryoffset + offsetof(struct hfsplus_cat_file, rsrc_fork);
hfs_bnode_read(fd.bnode, &fork, off, sizeof(fork));
hfsplus_free_fork(sb, cnid, &fork, HFSPLUS_TYPE_RSRC);
}
list_for_each(pos, &HFSPLUS_I(dir)->open_dir_list) {
struct hfsplus_readdir_data *rd =
list_entry(pos, struct hfsplus_readdir_data, list);
if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
rd->file->f_pos--;
}
err = hfs_brec_remove(&fd);
if (err)
goto out;
hfsplus_cat_build_key(sb, fd.search_key, cnid, NULL);
err = hfs_brec_find(&fd);
if (err)
goto out;
err = hfs_brec_remove(&fd);
if (err)
goto out;
dir->i_size--;
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
out:
hfs_find_exit(&fd);
return err;
}
int hfsplus_rename_cat(u32 cnid,
struct inode *src_dir, struct qstr *src_name,
struct inode *dst_dir, struct qstr *dst_name)
{
struct super_block *sb = src_dir->i_sb;
struct hfs_find_data src_fd, dst_fd;
hfsplus_cat_entry entry;
int entry_size, type;
int err = 0;
dprint(DBG_CAT_MOD, "rename_cat: %u - %lu,%s - %lu,%s\n", cnid, src_dir->i_ino, src_name->name,
dst_dir->i_ino, dst_name->name);
hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &src_fd);
dst_fd = src_fd;
/* find the old dir entry and read the data */
hfsplus_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
err = hfs_brec_find(&src_fd);
if (err)
goto out;
hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
src_fd.entrylength);
/* create new dir entry with the data from the old entry */
hfsplus_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
err = hfs_brec_find(&dst_fd);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto out;
}
err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
if (err)
goto out;
dst_dir->i_size++;
dst_dir->i_mtime = dst_dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dst_dir);
/* finally remove the old entry */
hfsplus_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
err = hfs_brec_find(&src_fd);
if (err)
goto out;
err = hfs_brec_remove(&src_fd);
if (err)
goto out;
src_dir->i_size--;
src_dir->i_mtime = src_dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(src_dir);
/* remove old thread entry */
hfsplus_cat_build_key(sb, src_fd.search_key, cnid, NULL);
err = hfs_brec_find(&src_fd);
if (err)
goto out;
type = hfs_bnode_read_u16(src_fd.bnode, src_fd.entryoffset);
err = hfs_brec_remove(&src_fd);
if (err)
goto out;
/* create new thread entry */
hfsplus_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
entry_size = hfsplus_fill_cat_thread(sb, &entry, type, dst_dir->i_ino, dst_name);
err = hfs_brec_find(&dst_fd);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto out;
}
err = hfs_brec_insert(&dst_fd, &entry, entry_size);
out:
hfs_bnode_put(dst_fd.bnode);
hfs_find_exit(&src_fd);
return err;
}