android_kernel_xiaomi_sm8350/fs/hfsplus/catalog.c
Ernesto A. Fernández d92915c35b hfsplus: prevent btree data loss on ENOSPC
Inserting or deleting a record in a btree may require splitting several of
its nodes.  If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost.  This could mean lost inodes,
extents or xattrs.

Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.

The patch can be tested with xfstests generic/027.

Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:13 -07:00

550 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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);
}
/* Generates key for catalog file/folders record. */
int hfsplus_cat_build_key(struct super_block *sb,
hfsplus_btree_key *key, u32 parent, const struct qstr *str)
{
int len, err;
key->cat.parent = cpu_to_be32(parent);
err = hfsplus_asc2uni(sb, &key->cat.name, HFSPLUS_MAX_STRLEN,
str->name, str->len);
if (unlikely(err < 0))
return err;
len = be16_to_cpu(key->cat.name.length);
key->key_len = cpu_to_be16(6 + 2 * len);
return 0;
}
/* Generates key for catalog thread record. */
void hfsplus_cat_build_key_with_cnid(struct super_block *sb,
hfsplus_btree_key *key, u32 parent)
{
key->cat.parent = cpu_to_be32(parent);
key->cat.name.length = 0;
key->key_len = cpu_to_be16(6);
}
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);
}
void hfsplus_cat_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;
perms->userflags = HFSPLUS_I(inode)->userflags;
perms->mode = cpu_to_be16(inode->i_mode);
perms->owner = cpu_to_be32(i_uid_read(inode));
perms->group = cpu_to_be32(i_gid_read(inode));
if (S_ISREG(inode->i_mode))
perms->dev = cpu_to_be32(inode->i_nlink);
else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode))
perms->dev = cpu_to_be32(inode->i_rdev);
else
perms->dev = 0;
}
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);
if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags))
folder->flags |= cpu_to_be16(HFSPLUS_HAS_FOLDER_COUNT);
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_cat_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_cat_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 (HFSPLUS_FLG_IMMUTABLE &
(file->permissions.rootflags |
file->permissions.userflags))
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, const struct qstr *str)
{
int err;
entry->type = cpu_to_be16(type);
entry->thread.reserved = 0;
entry->thread.parentID = cpu_to_be32(parentid);
err = hfsplus_asc2uni(sb, &entry->thread.nodeName, HFSPLUS_MAX_STRLEN,
str->name, str->len);
if (unlikely(err < 0))
return err;
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_with_cnid(sb, fd->search_key, cnid);
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) {
pr_err("found bad thread record in catalog\n");
return -EIO;
}
if (be16_to_cpu(tmp.thread.nodeName.length) > 255) {
pr_err("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, hfs_find_rec_by_key);
}
static void hfsplus_subfolders_inc(struct inode *dir)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags)) {
/*
* Increment subfolder count. Note, the value is only meaningful
* for folders with HFSPLUS_HAS_FOLDER_COUNT flag set.
*/
HFSPLUS_I(dir)->subfolders++;
}
}
static void hfsplus_subfolders_dec(struct inode *dir)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags)) {
/*
* Decrement subfolder count. Note, the value is only meaningful
* for folders with HFSPLUS_HAS_FOLDER_COUNT flag set.
*
* Check for zero. Some subfolders may have been created
* by an implementation ignorant of this counter.
*/
if (HFSPLUS_I(dir)->subfolders)
HFSPLUS_I(dir)->subfolders--;
}
}
int hfsplus_create_cat(u32 cnid, struct inode *dir,
const 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;
hfs_dbg(CAT_MOD, "create_cat: %s,%u(%d)\n",
str->name, cnid, inode->i_nlink);
err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
if (err)
return err;
/*
* Fail early and avoid ENOSPC during the btree operations. We may
* have to split the root node at most once.
*/
err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth);
if (err)
goto err2;
hfsplus_cat_build_key_with_cnid(sb, fd.search_key, cnid);
entry_size = hfsplus_fill_cat_thread(sb, &entry,
S_ISDIR(inode->i_mode) ?
HFSPLUS_FOLDER_THREAD : HFSPLUS_FILE_THREAD,
dir->i_ino, str);
if (unlikely(entry_size < 0)) {
err = entry_size;
goto err2;
}
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto err2;
}
err = hfs_brec_insert(&fd, &entry, entry_size);
if (err)
goto err2;
err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, str);
if (unlikely(err))
goto err1;
entry_size = hfsplus_cat_build_record(&entry, cnid, inode);
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
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++;
if (S_ISDIR(inode->i_mode))
hfsplus_subfolders_inc(dir);
dir->i_mtime = dir->i_ctime = current_time(dir);
hfsplus_mark_inode_dirty(dir, HFSPLUS_I_CAT_DIRTY);
hfs_find_exit(&fd);
return 0;
err1:
hfsplus_cat_build_key_with_cnid(sb, fd.search_key, cnid);
if (!hfs_brec_find(&fd, hfs_find_rec_by_key))
hfs_brec_remove(&fd);
err2:
hfs_find_exit(&fd);
return err;
}
int hfsplus_delete_cat(u32 cnid, struct inode *dir, const 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;
hfs_dbg(CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
if (err)
return err;
/*
* Fail early and avoid ENOSPC during the btree operations. We may
* have to split the root node at most once.
*/
err = hfs_bmap_reserve(fd.tree, 2 * (int)fd.tree->depth - 2);
if (err)
goto out;
if (!str) {
int len;
hfsplus_cat_build_key_with_cnid(sb, fd.search_key, cnid);
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
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 {
err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, str);
if (unlikely(err))
goto out;
}
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
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);
}
/* we only need to take spinlock for exclusion with ->release() */
spin_lock(&HFSPLUS_I(dir)->open_dir_lock);
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--;
}
spin_unlock(&HFSPLUS_I(dir)->open_dir_lock);
err = hfs_brec_remove(&fd);
if (err)
goto out;
hfsplus_cat_build_key_with_cnid(sb, fd.search_key, cnid);
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
if (err)
goto out;
err = hfs_brec_remove(&fd);
if (err)
goto out;
dir->i_size--;
if (type == HFSPLUS_FOLDER)
hfsplus_subfolders_dec(dir);
dir->i_mtime = dir->i_ctime = current_time(dir);
hfsplus_mark_inode_dirty(dir, HFSPLUS_I_CAT_DIRTY);
if (type == HFSPLUS_FILE || type == HFSPLUS_FOLDER) {
if (HFSPLUS_SB(sb)->attr_tree)
hfsplus_delete_all_attrs(dir, cnid);
}
out:
hfs_find_exit(&fd);
return err;
}
int hfsplus_rename_cat(u32 cnid,
struct inode *src_dir, const struct qstr *src_name,
struct inode *dst_dir, const 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;
hfs_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);
err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &src_fd);
if (err)
return err;
dst_fd = src_fd;
/*
* Fail early and avoid ENOSPC during the btree operations. We may
* have to split the root node at most twice.
*/
err = hfs_bmap_reserve(src_fd.tree, 4 * (int)src_fd.tree->depth - 1);
if (err)
goto out;
/* find the old dir entry and read the data */
err = hfsplus_cat_build_key(sb, src_fd.search_key,
src_dir->i_ino, src_name);
if (unlikely(err))
goto out;
err = hfs_brec_find(&src_fd, hfs_find_rec_by_key);
if (err)
goto out;
if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
err = -EIO;
goto out;
}
hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
src_fd.entrylength);
type = be16_to_cpu(entry.type);
/* create new dir entry with the data from the old entry */
err = hfsplus_cat_build_key(sb, dst_fd.search_key,
dst_dir->i_ino, dst_name);
if (unlikely(err))
goto out;
err = hfs_brec_find(&dst_fd, hfs_find_rec_by_key);
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++;
if (type == HFSPLUS_FOLDER)
hfsplus_subfolders_inc(dst_dir);
dst_dir->i_mtime = dst_dir->i_ctime = current_time(dst_dir);
/* finally remove the old entry */
err = hfsplus_cat_build_key(sb, src_fd.search_key,
src_dir->i_ino, src_name);
if (unlikely(err))
goto out;
err = hfs_brec_find(&src_fd, hfs_find_rec_by_key);
if (err)
goto out;
err = hfs_brec_remove(&src_fd);
if (err)
goto out;
src_dir->i_size--;
if (type == HFSPLUS_FOLDER)
hfsplus_subfolders_dec(src_dir);
src_dir->i_mtime = src_dir->i_ctime = current_time(src_dir);
/* remove old thread entry */
hfsplus_cat_build_key_with_cnid(sb, src_fd.search_key, cnid);
err = hfs_brec_find(&src_fd, hfs_find_rec_by_key);
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_with_cnid(sb, dst_fd.search_key, cnid);
entry_size = hfsplus_fill_cat_thread(sb, &entry, type,
dst_dir->i_ino, dst_name);
if (unlikely(entry_size < 0)) {
err = entry_size;
goto out;
}
err = hfs_brec_find(&dst_fd, hfs_find_rec_by_key);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto out;
}
err = hfs_brec_insert(&dst_fd, &entry, entry_size);
hfsplus_mark_inode_dirty(dst_dir, HFSPLUS_I_CAT_DIRTY);
hfsplus_mark_inode_dirty(src_dir, HFSPLUS_I_CAT_DIRTY);
out:
hfs_bnode_put(dst_fd.bnode);
hfs_find_exit(&src_fd);
return err;
}