swh:1:snp:32555a3fd8878f019c2ebd6c964bc1edcaeff337
Tip revision: 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 authored by Linus Torvalds on 25 April 2021, 20:49:08 UTC
Linux 5.12
Linux 5.12
Tip revision: 9f4ad9e
attributes.c
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hfsplus/attributes.c
*
* Vyacheslav Dubeyko <slava@dubeyko.com>
*
* Handling of records in attributes tree
*/
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
static struct kmem_cache *hfsplus_attr_tree_cachep;
int __init hfsplus_create_attr_tree_cache(void)
{
if (hfsplus_attr_tree_cachep)
return -EEXIST;
hfsplus_attr_tree_cachep =
kmem_cache_create("hfsplus_attr_cache",
sizeof(hfsplus_attr_entry), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!hfsplus_attr_tree_cachep)
return -ENOMEM;
return 0;
}
void hfsplus_destroy_attr_tree_cache(void)
{
kmem_cache_destroy(hfsplus_attr_tree_cachep);
}
int hfsplus_attr_bin_cmp_key(const hfsplus_btree_key *k1,
const hfsplus_btree_key *k2)
{
__be32 k1_cnid, k2_cnid;
k1_cnid = k1->attr.cnid;
k2_cnid = k2->attr.cnid;
if (k1_cnid != k2_cnid)
return be32_to_cpu(k1_cnid) < be32_to_cpu(k2_cnid) ? -1 : 1;
return hfsplus_strcmp(
(const struct hfsplus_unistr *)&k1->attr.key_name,
(const struct hfsplus_unistr *)&k2->attr.key_name);
}
int hfsplus_attr_build_key(struct super_block *sb, hfsplus_btree_key *key,
u32 cnid, const char *name)
{
int len;
memset(key, 0, sizeof(struct hfsplus_attr_key));
key->attr.cnid = cpu_to_be32(cnid);
if (name) {
int res = hfsplus_asc2uni(sb,
(struct hfsplus_unistr *)&key->attr.key_name,
HFSPLUS_ATTR_MAX_STRLEN, name, strlen(name));
if (res)
return res;
len = be16_to_cpu(key->attr.key_name.length);
} else {
key->attr.key_name.length = 0;
len = 0;
}
/* The length of the key, as stored in key_len field, does not include
* the size of the key_len field itself.
* So, offsetof(hfsplus_attr_key, key_name) is a trick because
* it takes into consideration key_len field (__be16) of
* hfsplus_attr_key structure instead of length field (__be16) of
* hfsplus_attr_unistr structure.
*/
key->key_len =
cpu_to_be16(offsetof(struct hfsplus_attr_key, key_name) +
2 * len);
return 0;
}
hfsplus_attr_entry *hfsplus_alloc_attr_entry(void)
{
return kmem_cache_alloc(hfsplus_attr_tree_cachep, GFP_KERNEL);
}
void hfsplus_destroy_attr_entry(hfsplus_attr_entry *entry)
{
if (entry)
kmem_cache_free(hfsplus_attr_tree_cachep, entry);
}
#define HFSPLUS_INVALID_ATTR_RECORD -1
static int hfsplus_attr_build_record(hfsplus_attr_entry *entry, int record_type,
u32 cnid, const void *value, size_t size)
{
if (record_type == HFSPLUS_ATTR_FORK_DATA) {
/*
* Mac OS X supports only inline data attributes.
* Do nothing
*/
memset(entry, 0, sizeof(*entry));
return sizeof(struct hfsplus_attr_fork_data);
} else if (record_type == HFSPLUS_ATTR_EXTENTS) {
/*
* Mac OS X supports only inline data attributes.
* Do nothing.
*/
memset(entry, 0, sizeof(*entry));
return sizeof(struct hfsplus_attr_extents);
} else if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
u16 len;
memset(entry, 0, sizeof(struct hfsplus_attr_inline_data));
entry->inline_data.record_type = cpu_to_be32(record_type);
if (size <= HFSPLUS_MAX_INLINE_DATA_SIZE)
len = size;
else
return HFSPLUS_INVALID_ATTR_RECORD;
entry->inline_data.length = cpu_to_be16(len);
memcpy(entry->inline_data.raw_bytes, value, len);
/*
* Align len on two-byte boundary.
* It needs to add pad byte if we have odd len.
*/
len = round_up(len, 2);
return offsetof(struct hfsplus_attr_inline_data, raw_bytes) +
len;
} else /* invalid input */
memset(entry, 0, sizeof(*entry));
return HFSPLUS_INVALID_ATTR_RECORD;
}
int hfsplus_find_attr(struct super_block *sb, u32 cnid,
const char *name, struct hfs_find_data *fd)
{
int err = 0;
hfs_dbg(ATTR_MOD, "find_attr: %s,%d\n", name ? name : NULL, cnid);
if (!HFSPLUS_SB(sb)->attr_tree) {
pr_err("attributes file doesn't exist\n");
return -EINVAL;
}
if (name) {
err = hfsplus_attr_build_key(sb, fd->search_key, cnid, name);
if (err)
goto failed_find_attr;
err = hfs_brec_find(fd, hfs_find_rec_by_key);
if (err)
goto failed_find_attr;
} else {
err = hfsplus_attr_build_key(sb, fd->search_key, cnid, NULL);
if (err)
goto failed_find_attr;
err = hfs_brec_find(fd, hfs_find_1st_rec_by_cnid);
if (err)
goto failed_find_attr;
}
failed_find_attr:
return err;
}
int hfsplus_attr_exists(struct inode *inode, const char *name)
{
int err = 0;
struct super_block *sb = inode->i_sb;
struct hfs_find_data fd;
if (!HFSPLUS_SB(sb)->attr_tree)
return 0;
err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd);
if (err)
return 0;
err = hfsplus_find_attr(sb, inode->i_ino, name, &fd);
if (err)
goto attr_not_found;
hfs_find_exit(&fd);
return 1;
attr_not_found:
hfs_find_exit(&fd);
return 0;
}
int hfsplus_create_attr(struct inode *inode,
const char *name,
const void *value, size_t size)
{
struct super_block *sb = inode->i_sb;
struct hfs_find_data fd;
hfsplus_attr_entry *entry_ptr;
int entry_size;
int err;
hfs_dbg(ATTR_MOD, "create_attr: %s,%ld\n",
name ? name : NULL, inode->i_ino);
if (!HFSPLUS_SB(sb)->attr_tree) {
pr_err("attributes file doesn't exist\n");
return -EINVAL;
}
entry_ptr = hfsplus_alloc_attr_entry();
if (!entry_ptr)
return -ENOMEM;
err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd);
if (err)
goto failed_init_create_attr;
/* Fail early and avoid ENOSPC during the btree operation */
err = hfs_bmap_reserve(fd.tree, fd.tree->depth + 1);
if (err)
goto failed_create_attr;
if (name) {
err = hfsplus_attr_build_key(sb, fd.search_key,
inode->i_ino, name);
if (err)
goto failed_create_attr;
} else {
err = -EINVAL;
goto failed_create_attr;
}
/* Mac OS X supports only inline data attributes. */
entry_size = hfsplus_attr_build_record(entry_ptr,
HFSPLUS_ATTR_INLINE_DATA,
inode->i_ino,
value, size);
if (entry_size == HFSPLUS_INVALID_ATTR_RECORD) {
err = -EINVAL;
goto failed_create_attr;
}
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
if (err != -ENOENT) {
if (!err)
err = -EEXIST;
goto failed_create_attr;
}
err = hfs_brec_insert(&fd, entry_ptr, entry_size);
if (err)
goto failed_create_attr;
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ATTR_DIRTY);
failed_create_attr:
hfs_find_exit(&fd);
failed_init_create_attr:
hfsplus_destroy_attr_entry(entry_ptr);
return err;
}
static int __hfsplus_delete_attr(struct inode *inode, u32 cnid,
struct hfs_find_data *fd)
{
int err = 0;
__be32 found_cnid, record_type;
hfs_bnode_read(fd->bnode, &found_cnid,
fd->keyoffset +
offsetof(struct hfsplus_attr_key, cnid),
sizeof(__be32));
if (cnid != be32_to_cpu(found_cnid))
return -ENOENT;
hfs_bnode_read(fd->bnode, &record_type,
fd->entryoffset, sizeof(record_type));
switch (be32_to_cpu(record_type)) {
case HFSPLUS_ATTR_INLINE_DATA:
/* All is OK. Do nothing. */
break;
case HFSPLUS_ATTR_FORK_DATA:
case HFSPLUS_ATTR_EXTENTS:
pr_err("only inline data xattr are supported\n");
return -EOPNOTSUPP;
default:
pr_err("invalid extended attribute record\n");
return -ENOENT;
}
/* Avoid btree corruption */
hfs_bnode_read(fd->bnode, fd->search_key,
fd->keyoffset, fd->keylength);
err = hfs_brec_remove(fd);
if (err)
return err;
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ATTR_DIRTY);
return err;
}
int hfsplus_delete_attr(struct inode *inode, const char *name)
{
int err = 0;
struct super_block *sb = inode->i_sb;
struct hfs_find_data fd;
hfs_dbg(ATTR_MOD, "delete_attr: %s,%ld\n",
name ? name : NULL, inode->i_ino);
if (!HFSPLUS_SB(sb)->attr_tree) {
pr_err("attributes file doesn't exist\n");
return -EINVAL;
}
err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd);
if (err)
return err;
/* Fail early and avoid ENOSPC during the btree operation */
err = hfs_bmap_reserve(fd.tree, fd.tree->depth);
if (err)
goto out;
if (name) {
err = hfsplus_attr_build_key(sb, fd.search_key,
inode->i_ino, name);
if (err)
goto out;
} else {
pr_err("invalid extended attribute name\n");
err = -EINVAL;
goto out;
}
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
if (err)
goto out;
err = __hfsplus_delete_attr(inode, inode->i_ino, &fd);
if (err)
goto out;
out:
hfs_find_exit(&fd);
return err;
}
int hfsplus_delete_all_attrs(struct inode *dir, u32 cnid)
{
int err = 0;
struct hfs_find_data fd;
hfs_dbg(ATTR_MOD, "delete_all_attrs: %d\n", cnid);
if (!HFSPLUS_SB(dir->i_sb)->attr_tree) {
pr_err("attributes file doesn't exist\n");
return -EINVAL;
}
err = hfs_find_init(HFSPLUS_SB(dir->i_sb)->attr_tree, &fd);
if (err)
return err;
for (;;) {
err = hfsplus_find_attr(dir->i_sb, cnid, NULL, &fd);
if (err) {
if (err != -ENOENT)
pr_err("xattr search failed\n");
goto end_delete_all;
}
err = __hfsplus_delete_attr(dir, cnid, &fd);
if (err)
goto end_delete_all;
}
end_delete_all:
hfs_find_exit(&fd);
return err;
}