linux/fs/btrfs/props.c
Nikolay Borisov 63f018be57 btrfs: Remove __ prefix from btrfs_block_rsv_release
Currently the non-prefixed version is a simple wrapper used to hide
the 4th argument of the prefixed version. This doesn't bring much value
in practice and only makes the code harder to follow by adding another
level of indirection. Rectify this by removing the __ prefix and
have only one public function to release bytes from a block reservation.
No semantic changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:55 +01:00

448 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
*/
#include <linux/hashtable.h>
#include "props.h"
#include "btrfs_inode.h"
#include "transaction.h"
#include "ctree.h"
#include "xattr.h"
#include "compression.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 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 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(value, value_len);
}
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;
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 = 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;
}
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(BTRFS_I(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(BTRFS_I(inode));
int ret;
ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
return ret;
}
static int prop_compression_validate(const char *value, size_t len)
{
if (!value)
return 0;
if (btrfs_compress_is_valid_type(value, len))
return 0;
return -EINVAL;
}
static int prop_compression_apply(struct inode *inode, const char *value,
size_t len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
int type;
if (len == 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 const char *prop_compression_extract(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,
.inheritable = 1
},
};
static int inherit_props(struct btrfs_trans_handle *trans,
struct inode *inode,
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;
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 futher.
*/
ret = h->validate(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(root, 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 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 super_block *sb = root->fs_info->sb;
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(sb, &key, parent_root);
if (IS_ERR(parent_inode))
return PTR_ERR(parent_inode);
child_inode = btrfs_iget(sb, &key, root);
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;
}
void __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);
}
}