blob: dca137b04095fc509390b2c02d4ca6ad1752ee74 [file] [log] [blame]
/*
* Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/hashtable.h>
#include "props.h"
#include "btrfs_inode.h"
#include "hash.h"
#include "transaction.h"
#include "xattr.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 char *value, size_t len);
int (*apply)(struct inode *inode, const char *value, size_t len);
const char *(*extract)(struct inode *inode);
int inheritable;
};
static int prop_compression_validate(const char *value, size_t len);
static int prop_compression_apply(struct inode *inode,
const char *value,
size_t len);
static const char *prop_compression_extract(struct inode *inode);
static struct prop_handler prop_handlers[] = {
{
.xattr_name = XATTR_BTRFS_PREFIX "compression",
.validate = prop_compression_validate,
.apply = prop_compression_apply,
.extract = prop_compression_extract,
.inheritable = 1
},
{
.xattr_name = NULL
}
};
void __init btrfs_props_init(void)
{
struct prop_handler *p;
hash_init(prop_handlers_ht);
for (p = &prop_handlers[0]; p->xattr_name; p++) {
u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
hash_add(prop_handlers_ht, &p->node, h);
}
}
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;
}
static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
struct inode *inode,
const char *name,
const char *value,
size_t value_len,
int flags)
{
const struct prop_handler *handler;
int ret;
if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
return -EINVAL;
handler = find_prop_handler(name, NULL);
if (!handler)
return -EINVAL;
if (value_len == 0) {
ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
NULL, 0, flags);
if (ret)
return ret;
ret = handler->apply(inode, NULL, 0);
ASSERT(ret == 0);
return ret;
}
ret = handler->validate(value, value_len);
if (ret)
return ret;
ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
value, value_len, flags);
if (ret)
return ret;
ret = handler->apply(inode, value, value_len);
if (ret) {
__btrfs_setxattr(trans, inode, handler->xattr_name,
NULL, 0, flags);
return ret;
}
set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
return 0;
}
int btrfs_set_prop(struct inode *inode,
const char *name,
const char *value,
size_t value_len,
int flags)
{
return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
}
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_nr(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(inode),
root->root_key.objectid, 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(inode);
int ret;
ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
return ret;
}
static int inherit_props(struct btrfs_trans_handle *trans,
struct inode *inode,
struct inode *parent)
{
const struct prop_handler *h;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
if (!test_bit(BTRFS_INODE_HAS_PROPS,
&BTRFS_I(parent)->runtime_flags))
return 0;
for (h = &prop_handlers[0]; h->xattr_name; h++) {
const char *value;
u64 num_bytes;
if (!h->inheritable)
continue;
value = h->extract(parent);
if (!value)
continue;
num_bytes = btrfs_calc_trans_metadata_size(root, 1);
ret = btrfs_block_rsv_add(root, trans->block_rsv,
num_bytes, BTRFS_RESERVE_NO_FLUSH);
if (ret)
goto out;
ret = __btrfs_set_prop(trans, inode, h->xattr_name,
value, strlen(value), 0);
btrfs_block_rsv_release(root, trans->block_rsv, num_bytes);
if (ret)
goto out;
}
ret = 0;
out:
return ret;
}
int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
struct inode *inode,
struct inode *dir)
{
if (!dir)
return 0;
return inherit_props(trans, inode, dir);
}
int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *parent_root)
{
struct btrfs_key key;
struct inode *parent_inode, *child_inode;
int ret;
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
parent_inode = btrfs_iget(parent_root->fs_info->sb, &key,
parent_root, NULL);
if (IS_ERR(parent_inode))
return PTR_ERR(parent_inode);
child_inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
if (IS_ERR(child_inode)) {
iput(parent_inode);
return PTR_ERR(child_inode);
}
ret = inherit_props(trans, child_inode, parent_inode);
iput(child_inode);
iput(parent_inode);
return ret;
}
static int prop_compression_validate(const char *value, size_t len)
{
if (!strncmp("lzo", value, len))
return 0;
else if (!strncmp("zlib", value, len))
return 0;
return -EINVAL;
}
static int prop_compression_apply(struct inode *inode,
const char *value,
size_t len)
{
int type;
if (len == 0) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
return 0;
}
if (!strncmp("lzo", value, len))
type = BTRFS_COMPRESS_LZO;
else if (!strncmp("zlib", value, len))
type = BTRFS_COMPRESS_ZLIB;
else
return -EINVAL;
BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->force_compress = type;
return 0;
}
static const char *prop_compression_extract(struct inode *inode)
{
switch (BTRFS_I(inode)->force_compress) {
case BTRFS_COMPRESS_ZLIB:
return "zlib";
case BTRFS_COMPRESS_LZO:
return "lzo";
}
return NULL;
}