// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Filipe David Borba Manana <[email protected]>
*/
#include <linux/hashtable.h>
#include <linux/xattr.h>
#include "messages.h"
#include "props.h"
#include "btrfs_inode.h"
#include "transaction.h"
#include "ctree.h"
#include "xattr.h"
#include "compression.h"
#include "space-info.h"
#include "fs.h"
#include "accessors.h"
#include "super.h"
#include "dir-item.h"
#define BTRFS_PROP_HANDLERS_HT_BITS 8
static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
struct prop_handler {
struct hlist_node node;
const char *xattr_name;
int (*validate)(const struct btrfs_inode *inode, const char *value,
size_t len);
int (*apply)(struct inode *inode, const char *value, size_t len);
const char *(*extract)(const struct inode *inode);
bool (*ignore)(const struct btrfs_inode *inode);
int inheritable;
};
static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
{
struct hlist_head *h;
h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
if (hlist_empty(h))
return NULL;
return h;
}
static const struct prop_handler *
find_prop_handler(const char *name,
const struct hlist_head *handlers)
{
struct prop_handler *h;
if (!handlers) {
u64 hash = btrfs_name_hash(name, strlen(name));
handlers = find_prop_handlers_by_hash(hash);
if (!handlers)
return NULL;
}
hlist_for_each_entry(h, handlers, node)
if (!strcmp(h->xattr_name, name))
return h;
return NULL;
}
int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
const char *value, size_t value_len)
{
const struct prop_handler *handler;
if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
return -EINVAL;
handler = find_prop_handler(name, NULL);
if (!handler)
return -EINVAL;
if (value_len == 0)
return 0;
return handler->validate(inode, value, value_len);
}
/*
* Check if a property should be ignored (not set) for an inode.
*
* @inode: The target inode.
* @name: The property's name.
*
* The caller must be sure the given property name is valid, for example by
* having previously called btrfs_validate_prop().
*
* Returns: true if the property should be ignored for the given inode
* false if the property must not be ignored for the given inode
*/
bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
{
const struct prop_handler *handler;
handler = find_prop_handler(name, NULL);
ASSERT(handler != NULL);
return handler->ignore(inode);
}
int btrfs_set_prop(struct btrfs_trans_handle *trans, struct btrfs_inode *inode,
const char *name, const char *value, size_t value_len,
int flags)
{
const struct prop_handler *handler;
int ret;
handler = find_prop_handler(name, NULL);
if (!handler)
return -EINVAL;
if (value_len == 0) {
ret = btrfs_setxattr(trans, &inode->vfs_inode, handler->xattr_name,
NULL, 0, flags);
if (ret)
return ret;
ret = handler->apply(&inode->vfs_inode, NULL, 0);
ASSERT(ret == 0);
return ret;
}
ret = btrfs_setxattr(trans, &inode->vfs_inode, handler->xattr_name, value,
value_len, flags);
if (ret)
return ret;
ret = handler->apply(&inode->vfs_inode, value, value_len);
if (ret) {
btrfs_setxattr(trans, &inode->vfs_inode, handler->xattr_name, NULL,
0, flags);
return ret;
}
set_bit(BTRFS_INODE_HAS_PROPS, &inode->runtime_flags);
return 0;
}
static int iterate_object_props(struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid,
void (*iterator)(void *,
const struct prop_handler *,
const char *,
size_t),
void *ctx)
{
int ret;
char *name_buf = NULL;
char *value_buf = NULL;
int name_buf_len = 0;
int value_buf_len = 0;
while (1) {
struct btrfs_key key;
struct btrfs_dir_item *di;
struct extent_buffer *leaf;
u32 total_len, cur, this_len;
int slot;
const struct hlist_head *handlers;
slot = path->slots[0];
leaf = path->nodes[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != objectid)
break;
if (key.type != BTRFS_XATTR_ITEM_KEY)
break;
handlers = find_prop_handlers_by_hash(key.offset);
if (!handlers)
goto next_slot;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
cur = 0;
total_len = btrfs_item_size(leaf, slot);
while (cur < total_len) {
u32 name_len = btrfs_dir_name_len(leaf, di);
u32 data_len = btrfs_dir_data_len(leaf, di);
unsigned long name_ptr, data_ptr;
const struct prop_handler *handler;
this_len = sizeof(*di) + name_len + data_len;
name_ptr = (unsigned long)(di + 1);
data_ptr = name_ptr + name_len;
if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
name_ptr,
XATTR_BTRFS_PREFIX_LEN))
goto next_dir_item;
if (name_len >= name_buf_len) {
kfree(name_buf);
name_buf_len = name_len + 1;
name_buf = kmalloc(name_buf_len, GFP_NOFS);
if (!name_buf) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, name_buf, name_ptr, name_len);
name_buf[name_len] = '\0';
handler = find_prop_handler(name_buf, handlers);
if (!handler)
goto next_dir_item;
if (data_len > value_buf_len) {
kfree(value_buf);
value_buf_len = data_len;
value_buf = kmalloc(data_len, GFP_NOFS);
if (!value_buf) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, value_buf, data_ptr, data_len);
iterator(ctx, handler, value_buf, data_len);
next_dir_item:
cur += this_len;
di = (struct btrfs_dir_item *)((char *) di + this_len);
}
next_slot:
path->slots[0]++;
}
ret = 0;
out:
btrfs_release_path(path);
kfree(name_buf);
kfree(value_buf);
return ret;
}
static void inode_prop_iterator(void *ctx,
const struct prop_handler *handler,
const char *value,
size_t len)
{
struct inode *inode = ctx;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = handler->apply(inode, value, len);
if (unlikely(ret))
btrfs_warn(root->fs_info,
"error applying prop %s to ino %llu (root %llu): %d",
handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
btrfs_root_id(root), ret);
else
set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
}
int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 ino = btrfs_ino(BTRFS_I(inode));
return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
}
static int prop_compression_validate(const struct btrfs_inode *inode,
const char *value, size_t len)
{
if (!btrfs_inode_can_compress(inode))
return -EINVAL;
if (!value)
return 0;
if (btrfs_compress_is_valid_type(value, len))
return 0;
if ((len == 2 && strncmp("no", value, 2) == 0) ||
(len == 4 && strncmp("none", value, 4) == 0))
return 0;
return -EINVAL;
}
static int prop_compression_apply(struct inode *inode, const char *value,
size_t len)
{
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
int type;
/* Reset to defaults */
if (len == 0) {
BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
return 0;
}
/* Set NOCOMPRESS flag */
if ((len == 2 && strncmp("no", value, 2) == 0) ||
(len == 4 && strncmp("none", value, 4) == 0)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
return 0;
}
if (!strncmp("lzo", value, 3)) {
type = BTRFS_COMPRESS_LZO;
btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
} else if (!strncmp("zlib", value, 4)) {
type = BTRFS_COMPRESS_ZLIB;
} else if (!strncmp("zstd", value, 4)) {
type = BTRFS_COMPRESS_ZSTD;
btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
} else {
return -EINVAL;
}
BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->prop_compress = type;
return 0;
}
static bool prop_compression_ignore(const struct btrfs_inode *inode)
{
/*
* Compression only has effect for regular files, and for directories
* we set it just to propagate it to new files created inside them.
* Everything else (symlinks, devices, sockets, fifos) is pointless as
* it will do nothing, so don't waste metadata space on a compression
* xattr for anything that is neither a file nor a directory.
*/
if (!S_ISREG(inode->vfs_inode.i_mode) &&
!S_ISDIR(inode->vfs_inode.i_mode))
return true;
return false;
}
static const char *prop_compression_extract(const struct inode *inode)
{
switch (BTRFS_I(inode)->prop_compress) {
case BTRFS_COMPRESS_ZLIB:
case BTRFS_COMPRESS_LZO:
case BTRFS_COMPRESS_ZSTD:
return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
default:
break;
}
return NULL;
}
static struct prop_handler prop_handlers[] = {
{
.xattr_name = XATTR_BTRFS_PREFIX "compression",
.validate = prop_compression_validate,
.apply = prop_compression_apply,
.extract = prop_compression_extract,
.ignore = prop_compression_ignore,
.inheritable = 1
},
};
int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
struct inode *inode, const struct inode *parent)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
int i;
bool need_reserve = false;
if (!test_bit(BTRFS_INODE_HAS_PROPS,
&BTRFS_I(parent)->runtime_flags))
return 0;
for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
const struct prop_handler *h = &prop_handlers[i];
const char *value;
u64 num_bytes = 0;
if (!h->inheritable)
continue;
if (h->ignore(BTRFS_I(inode)))
continue;
value = h->extract(parent);
if (!value)
continue;
/*
* This is not strictly necessary as the property should be
* valid, but in case it isn't, don't propagate it further.
*/
ret = h->validate(BTRFS_I(inode), value, strlen(value));
if (ret)
continue;
/*
* Currently callers should be reserving 1 item for properties,
* since we only have 1 property that we currently support. If
* we add more in the future we need to try and reserve more
* space for them. But we should also revisit how we do space
* reservations if we do add more properties in the future.
*/
if (need_reserve) {
num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
num_bytes,
BTRFS_RESERVE_NO_FLUSH);
if (ret)
return ret;
}
ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
strlen(value), 0);
if (!ret) {
ret = h->apply(inode, value, strlen(value));
if (ret)
btrfs_setxattr(trans, inode, h->xattr_name,
NULL, 0, 0);
else
set_bit(BTRFS_INODE_HAS_PROPS,
&BTRFS_I(inode)->runtime_flags);
}
if (need_reserve) {
btrfs_block_rsv_release(fs_info, trans->block_rsv,
num_bytes, NULL);
if (ret)
return ret;
}
need_reserve = true;
}
return 0;
}
int __init btrfs_props_init(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
struct prop_handler *p = &prop_handlers[i];
u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
hash_add(prop_handlers_ht, &p->node, h);
}
return 0;
}
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