mirror of
https://github.com/torvalds/linux.git
synced 2024-12-06 11:01:43 +00:00
54640c7502
Inserting a new 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 or extents. Henceforth, check the available disk space before making any changes. This still leaves the potential problem of corruption on ENOMEM. There is no need to reserve space before deleting a catalog record, as we do for hfsplus. This difference is because hfs index nodes have fixed length keys. Link: http://lkml.kernel.org/r/ab5fc8a7d5ffccfd5f27b1cf2cb4ceb6c110da74.1536269131.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>
380 lines
8.9 KiB
C
380 lines
8.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/fs/hfs/btree.c
|
|
*
|
|
* Copyright (C) 2001
|
|
* Brad Boyer (flar@allandria.com)
|
|
* (C) 2003 Ardis Technologies <roman@ardistech.com>
|
|
*
|
|
* Handle opening/closing btree
|
|
*/
|
|
|
|
#include <linux/pagemap.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/log2.h>
|
|
|
|
#include "btree.h"
|
|
|
|
/* Get a reference to a B*Tree and do some initial checks */
|
|
struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
|
|
{
|
|
struct hfs_btree *tree;
|
|
struct hfs_btree_header_rec *head;
|
|
struct address_space *mapping;
|
|
struct page *page;
|
|
unsigned int size;
|
|
|
|
tree = kzalloc(sizeof(*tree), GFP_KERNEL);
|
|
if (!tree)
|
|
return NULL;
|
|
|
|
mutex_init(&tree->tree_lock);
|
|
spin_lock_init(&tree->hash_lock);
|
|
/* Set the correct compare function */
|
|
tree->sb = sb;
|
|
tree->cnid = id;
|
|
tree->keycmp = keycmp;
|
|
|
|
tree->inode = iget_locked(sb, id);
|
|
if (!tree->inode)
|
|
goto free_tree;
|
|
BUG_ON(!(tree->inode->i_state & I_NEW));
|
|
{
|
|
struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
|
|
HFS_I(tree->inode)->flags = 0;
|
|
mutex_init(&HFS_I(tree->inode)->extents_lock);
|
|
switch (id) {
|
|
case HFS_EXT_CNID:
|
|
hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
|
|
mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
|
|
if (HFS_I(tree->inode)->alloc_blocks >
|
|
HFS_I(tree->inode)->first_blocks) {
|
|
pr_err("invalid btree extent records\n");
|
|
unlock_new_inode(tree->inode);
|
|
goto free_inode;
|
|
}
|
|
|
|
tree->inode->i_mapping->a_ops = &hfs_btree_aops;
|
|
break;
|
|
case HFS_CAT_CNID:
|
|
hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
|
|
mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
|
|
|
|
if (!HFS_I(tree->inode)->first_blocks) {
|
|
pr_err("invalid btree extent records (0 size)\n");
|
|
unlock_new_inode(tree->inode);
|
|
goto free_inode;
|
|
}
|
|
|
|
tree->inode->i_mapping->a_ops = &hfs_btree_aops;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
unlock_new_inode(tree->inode);
|
|
|
|
mapping = tree->inode->i_mapping;
|
|
page = read_mapping_page(mapping, 0, NULL);
|
|
if (IS_ERR(page))
|
|
goto free_inode;
|
|
|
|
/* Load the header */
|
|
head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
|
|
tree->root = be32_to_cpu(head->root);
|
|
tree->leaf_count = be32_to_cpu(head->leaf_count);
|
|
tree->leaf_head = be32_to_cpu(head->leaf_head);
|
|
tree->leaf_tail = be32_to_cpu(head->leaf_tail);
|
|
tree->node_count = be32_to_cpu(head->node_count);
|
|
tree->free_nodes = be32_to_cpu(head->free_nodes);
|
|
tree->attributes = be32_to_cpu(head->attributes);
|
|
tree->node_size = be16_to_cpu(head->node_size);
|
|
tree->max_key_len = be16_to_cpu(head->max_key_len);
|
|
tree->depth = be16_to_cpu(head->depth);
|
|
|
|
size = tree->node_size;
|
|
if (!is_power_of_2(size))
|
|
goto fail_page;
|
|
if (!tree->node_count)
|
|
goto fail_page;
|
|
switch (id) {
|
|
case HFS_EXT_CNID:
|
|
if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
|
|
pr_err("invalid extent max_key_len %d\n",
|
|
tree->max_key_len);
|
|
goto fail_page;
|
|
}
|
|
break;
|
|
case HFS_CAT_CNID:
|
|
if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
|
|
pr_err("invalid catalog max_key_len %d\n",
|
|
tree->max_key_len);
|
|
goto fail_page;
|
|
}
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
tree->node_size_shift = ffs(size) - 1;
|
|
tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
|
|
kunmap(page);
|
|
put_page(page);
|
|
return tree;
|
|
|
|
fail_page:
|
|
put_page(page);
|
|
free_inode:
|
|
tree->inode->i_mapping->a_ops = &hfs_aops;
|
|
iput(tree->inode);
|
|
free_tree:
|
|
kfree(tree);
|
|
return NULL;
|
|
}
|
|
|
|
/* Release resources used by a btree */
|
|
void hfs_btree_close(struct hfs_btree *tree)
|
|
{
|
|
struct hfs_bnode *node;
|
|
int i;
|
|
|
|
if (!tree)
|
|
return;
|
|
|
|
for (i = 0; i < NODE_HASH_SIZE; i++) {
|
|
while ((node = tree->node_hash[i])) {
|
|
tree->node_hash[i] = node->next_hash;
|
|
if (atomic_read(&node->refcnt))
|
|
pr_err("node %d:%d still has %d user(s)!\n",
|
|
node->tree->cnid, node->this,
|
|
atomic_read(&node->refcnt));
|
|
hfs_bnode_free(node);
|
|
tree->node_hash_cnt--;
|
|
}
|
|
}
|
|
iput(tree->inode);
|
|
kfree(tree);
|
|
}
|
|
|
|
void hfs_btree_write(struct hfs_btree *tree)
|
|
{
|
|
struct hfs_btree_header_rec *head;
|
|
struct hfs_bnode *node;
|
|
struct page *page;
|
|
|
|
node = hfs_bnode_find(tree, 0);
|
|
if (IS_ERR(node))
|
|
/* panic? */
|
|
return;
|
|
/* Load the header */
|
|
page = node->page[0];
|
|
head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
|
|
|
|
head->root = cpu_to_be32(tree->root);
|
|
head->leaf_count = cpu_to_be32(tree->leaf_count);
|
|
head->leaf_head = cpu_to_be32(tree->leaf_head);
|
|
head->leaf_tail = cpu_to_be32(tree->leaf_tail);
|
|
head->node_count = cpu_to_be32(tree->node_count);
|
|
head->free_nodes = cpu_to_be32(tree->free_nodes);
|
|
head->attributes = cpu_to_be32(tree->attributes);
|
|
head->depth = cpu_to_be16(tree->depth);
|
|
|
|
kunmap(page);
|
|
set_page_dirty(page);
|
|
hfs_bnode_put(node);
|
|
}
|
|
|
|
static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
|
|
{
|
|
struct hfs_btree *tree = prev->tree;
|
|
struct hfs_bnode *node;
|
|
struct hfs_bnode_desc desc;
|
|
__be32 cnid;
|
|
|
|
node = hfs_bnode_create(tree, idx);
|
|
if (IS_ERR(node))
|
|
return node;
|
|
|
|
if (!tree->free_nodes)
|
|
panic("FIXME!!!");
|
|
tree->free_nodes--;
|
|
prev->next = idx;
|
|
cnid = cpu_to_be32(idx);
|
|
hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
|
|
|
|
node->type = HFS_NODE_MAP;
|
|
node->num_recs = 1;
|
|
hfs_bnode_clear(node, 0, tree->node_size);
|
|
desc.next = 0;
|
|
desc.prev = 0;
|
|
desc.type = HFS_NODE_MAP;
|
|
desc.height = 0;
|
|
desc.num_recs = cpu_to_be16(1);
|
|
desc.reserved = 0;
|
|
hfs_bnode_write(node, &desc, 0, sizeof(desc));
|
|
hfs_bnode_write_u16(node, 14, 0x8000);
|
|
hfs_bnode_write_u16(node, tree->node_size - 2, 14);
|
|
hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
|
|
|
|
return node;
|
|
}
|
|
|
|
/* Make sure @tree has enough space for the @rsvd_nodes */
|
|
int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
|
|
{
|
|
struct inode *inode = tree->inode;
|
|
u32 count;
|
|
int res;
|
|
|
|
while (tree->free_nodes < rsvd_nodes) {
|
|
res = hfs_extend_file(inode);
|
|
if (res)
|
|
return res;
|
|
HFS_I(inode)->phys_size = inode->i_size =
|
|
(loff_t)HFS_I(inode)->alloc_blocks *
|
|
HFS_SB(tree->sb)->alloc_blksz;
|
|
HFS_I(inode)->fs_blocks = inode->i_size >>
|
|
tree->sb->s_blocksize_bits;
|
|
inode_set_bytes(inode, inode->i_size);
|
|
count = inode->i_size >> tree->node_size_shift;
|
|
tree->free_nodes += count - tree->node_count;
|
|
tree->node_count = count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
|
|
{
|
|
struct hfs_bnode *node, *next_node;
|
|
struct page **pagep;
|
|
u32 nidx, idx;
|
|
unsigned off;
|
|
u16 off16;
|
|
u16 len;
|
|
u8 *data, byte, m;
|
|
int i, res;
|
|
|
|
res = hfs_bmap_reserve(tree, 1);
|
|
if (res)
|
|
return ERR_PTR(res);
|
|
|
|
nidx = 0;
|
|
node = hfs_bnode_find(tree, nidx);
|
|
if (IS_ERR(node))
|
|
return node;
|
|
len = hfs_brec_lenoff(node, 2, &off16);
|
|
off = off16;
|
|
|
|
off += node->page_offset;
|
|
pagep = node->page + (off >> PAGE_SHIFT);
|
|
data = kmap(*pagep);
|
|
off &= ~PAGE_MASK;
|
|
idx = 0;
|
|
|
|
for (;;) {
|
|
while (len) {
|
|
byte = data[off];
|
|
if (byte != 0xff) {
|
|
for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
|
|
if (!(byte & m)) {
|
|
idx += i;
|
|
data[off] |= m;
|
|
set_page_dirty(*pagep);
|
|
kunmap(*pagep);
|
|
tree->free_nodes--;
|
|
mark_inode_dirty(tree->inode);
|
|
hfs_bnode_put(node);
|
|
return hfs_bnode_create(tree, idx);
|
|
}
|
|
}
|
|
}
|
|
if (++off >= PAGE_SIZE) {
|
|
kunmap(*pagep);
|
|
data = kmap(*++pagep);
|
|
off = 0;
|
|
}
|
|
idx += 8;
|
|
len--;
|
|
}
|
|
kunmap(*pagep);
|
|
nidx = node->next;
|
|
if (!nidx) {
|
|
printk(KERN_DEBUG "create new bmap node...\n");
|
|
next_node = hfs_bmap_new_bmap(node, idx);
|
|
} else
|
|
next_node = hfs_bnode_find(tree, nidx);
|
|
hfs_bnode_put(node);
|
|
if (IS_ERR(next_node))
|
|
return next_node;
|
|
node = next_node;
|
|
|
|
len = hfs_brec_lenoff(node, 0, &off16);
|
|
off = off16;
|
|
off += node->page_offset;
|
|
pagep = node->page + (off >> PAGE_SHIFT);
|
|
data = kmap(*pagep);
|
|
off &= ~PAGE_MASK;
|
|
}
|
|
}
|
|
|
|
void hfs_bmap_free(struct hfs_bnode *node)
|
|
{
|
|
struct hfs_btree *tree;
|
|
struct page *page;
|
|
u16 off, len;
|
|
u32 nidx;
|
|
u8 *data, byte, m;
|
|
|
|
hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
|
|
tree = node->tree;
|
|
nidx = node->this;
|
|
node = hfs_bnode_find(tree, 0);
|
|
if (IS_ERR(node))
|
|
return;
|
|
len = hfs_brec_lenoff(node, 2, &off);
|
|
while (nidx >= len * 8) {
|
|
u32 i;
|
|
|
|
nidx -= len * 8;
|
|
i = node->next;
|
|
hfs_bnode_put(node);
|
|
if (!i) {
|
|
/* panic */;
|
|
pr_crit("unable to free bnode %u. bmap not found!\n",
|
|
node->this);
|
|
return;
|
|
}
|
|
node = hfs_bnode_find(tree, i);
|
|
if (IS_ERR(node))
|
|
return;
|
|
if (node->type != HFS_NODE_MAP) {
|
|
/* panic */;
|
|
pr_crit("invalid bmap found! (%u,%d)\n",
|
|
node->this, node->type);
|
|
hfs_bnode_put(node);
|
|
return;
|
|
}
|
|
len = hfs_brec_lenoff(node, 0, &off);
|
|
}
|
|
off += node->page_offset + nidx / 8;
|
|
page = node->page[off >> PAGE_SHIFT];
|
|
data = kmap(page);
|
|
off &= ~PAGE_MASK;
|
|
m = 1 << (~nidx & 7);
|
|
byte = data[off];
|
|
if (!(byte & m)) {
|
|
pr_crit("trying to free free bnode %u(%d)\n",
|
|
node->this, node->type);
|
|
kunmap(page);
|
|
hfs_bnode_put(node);
|
|
return;
|
|
}
|
|
data[off] = byte & ~m;
|
|
set_page_dirty(page);
|
|
kunmap(page);
|
|
hfs_bnode_put(node);
|
|
tree->free_nodes++;
|
|
mark_inode_dirty(tree->inode);
|
|
}
|