linux/fs/hfsplus/btree.c
Sergei Antonov 2cd282a1bc hfsplus: fix "unused node is not erased" error
Zero newly allocated extents in the catalog tree if volume attributes
tell us to.  Not doing so we risk getting the "unused node is not
erased" error.  See kHFSUnusedNodeFix flag in Apple's source code for
reference.

There was a previous commit clearing the node when it is freed: commit
899bed05e9 ("hfsplus: fix issue with unzeroed unused b-tree nodes").
But it did not handle newly allocated extents (this patch fixes it).
And it zeroed nodes in all trees unconditionally which is an overkill.

This patch adds a condition and also switches to 'tree->node_size' as a
simpler method of getting the length to zero.

Signed-off-by: Sergei Antonov <saproj@gmail.com>
Cc: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Kyle Laracey <kalaracey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:10 -07:00

498 lines
12 KiB
C

/*
* linux/fs/hfsplus/btree.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handle opening/closing btree
*/
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/log2.h>
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
/*
* Initial source code of clump size calculation is gotten
* from http://opensource.apple.com/tarballs/diskdev_cmds/
*/
#define CLUMP_ENTRIES 15
static short clumptbl[CLUMP_ENTRIES * 3] = {
/*
* Volume Attributes Catalog Extents
* Size Clump (MB) Clump (MB) Clump (MB)
*/
/* 1GB */ 4, 4, 4,
/* 2GB */ 6, 6, 4,
/* 4GB */ 8, 8, 4,
/* 8GB */ 11, 11, 5,
/*
* For volumes 16GB and larger, we want to make sure that a full OS
* install won't require fragmentation of the Catalog or Attributes
* B-trees. We do this by making the clump sizes sufficiently large,
* and by leaving a gap after the B-trees for them to grow into.
*
* For SnowLeopard 10A298, a FullNetInstall with all packages selected
* results in:
* Catalog B-tree Header
* nodeSize: 8192
* totalNodes: 31616
* freeNodes: 1978
* (used = 231.55 MB)
* Attributes B-tree Header
* nodeSize: 8192
* totalNodes: 63232
* freeNodes: 958
* (used = 486.52 MB)
*
* We also want Time Machine backup volumes to have a sufficiently
* large clump size to reduce fragmentation.
*
* The series of numbers for Catalog and Attribute form a geometric
* series. For Catalog (16GB to 512GB), each term is 8**(1/5) times
* the previous term. For Attributes (16GB to 512GB), each term is
* 4**(1/5) times the previous term. For 1TB to 16TB, each term is
* 2**(1/5) times the previous term.
*/
/* 16GB */ 64, 32, 5,
/* 32GB */ 84, 49, 6,
/* 64GB */ 111, 74, 7,
/* 128GB */ 147, 111, 8,
/* 256GB */ 194, 169, 9,
/* 512GB */ 256, 256, 11,
/* 1TB */ 294, 294, 14,
/* 2TB */ 338, 338, 16,
/* 4TB */ 388, 388, 20,
/* 8TB */ 446, 446, 25,
/* 16TB */ 512, 512, 32
};
u32 hfsplus_calc_btree_clump_size(u32 block_size, u32 node_size,
u64 sectors, int file_id)
{
u32 mod = max(node_size, block_size);
u32 clump_size;
int column;
int i;
/* Figure out which column of the above table to use for this file. */
switch (file_id) {
case HFSPLUS_ATTR_CNID:
column = 0;
break;
case HFSPLUS_CAT_CNID:
column = 1;
break;
default:
column = 2;
break;
}
/*
* The default clump size is 0.8% of the volume size. And
* it must also be a multiple of the node and block size.
*/
if (sectors < 0x200000) {
clump_size = sectors << 2; /* 0.8 % */
if (clump_size < (8 * node_size))
clump_size = 8 * node_size;
} else {
/* turn exponent into table index... */
for (i = 0, sectors = sectors >> 22;
sectors && (i < CLUMP_ENTRIES - 1);
++i, sectors = sectors >> 1) {
/* empty body */
}
clump_size = clumptbl[column + (i) * 3] * 1024 * 1024;
}
/*
* Round the clump size to a multiple of node and block size.
* NOTE: This rounds down.
*/
clump_size /= mod;
clump_size *= mod;
/*
* Rounding down could have rounded down to 0 if the block size was
* greater than the clump size. If so, just use one block or node.
*/
if (clump_size == 0)
clump_size = mod;
return clump_size;
}
/* Get a reference to a B*Tree and do some initial checks */
struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
{
struct hfs_btree *tree;
struct hfs_btree_header_rec *head;
struct address_space *mapping;
struct inode *inode;
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);
tree->sb = sb;
tree->cnid = id;
inode = hfsplus_iget(sb, id);
if (IS_ERR(inode))
goto free_tree;
tree->inode = inode;
if (!HFSPLUS_I(tree->inode)->first_blocks) {
pr_err("invalid btree extent records (0 size)\n");
goto free_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);
/* Verify the tree and set the correct compare function */
switch (id) {
case HFSPLUS_EXT_CNID:
if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
pr_err("invalid extent max_key_len %d\n",
tree->max_key_len);
goto fail_page;
}
if (tree->attributes & HFS_TREE_VARIDXKEYS) {
pr_err("invalid extent btree flag\n");
goto fail_page;
}
tree->keycmp = hfsplus_ext_cmp_key;
break;
case HFSPLUS_CAT_CNID:
if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
pr_err("invalid catalog max_key_len %d\n",
tree->max_key_len);
goto fail_page;
}
if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
pr_err("invalid catalog btree flag\n");
goto fail_page;
}
if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
(head->key_type == HFSPLUS_KEY_BINARY))
tree->keycmp = hfsplus_cat_bin_cmp_key;
else {
tree->keycmp = hfsplus_cat_case_cmp_key;
set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
}
break;
case HFSPLUS_ATTR_CNID:
if (tree->max_key_len != HFSPLUS_ATTR_KEYLEN - sizeof(u16)) {
pr_err("invalid attributes max_key_len %d\n",
tree->max_key_len);
goto fail_page;
}
tree->keycmp = hfsplus_attr_bin_cmp_key;
break;
default:
pr_err("unknown B*Tree requested\n");
goto fail_page;
}
if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
pr_err("invalid btree flag\n");
goto fail_page;
}
size = tree->node_size;
if (!is_power_of_2(size))
goto fail_page;
if (!tree->node_count)
goto fail_page;
tree->node_size_shift = ffs(size) - 1;
tree->pages_per_bnode =
(tree->node_size + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
kunmap(page);
page_cache_release(page);
return tree;
fail_page:
page_cache_release(page);
free_inode:
tree->inode->i_mapping->a_ops = &hfsplus_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_crit("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);
}
int 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 -EIO;
/* 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);
return 0;
}
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;
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;
}
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;
while (!tree->free_nodes) {
struct inode *inode = tree->inode;
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
u32 count;
int res;
res = hfsplus_file_extend(inode, hfs_bnode_need_zeroout(tree));
if (res)
return ERR_PTR(res);
hip->phys_size = inode->i_size =
(loff_t)hip->alloc_blocks <<
HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
hip->fs_blocks =
hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
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;
}
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_CACHE_SHIFT);
data = kmap(*pagep);
off &= ~PAGE_CACHE_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_CACHE_SIZE) {
kunmap(*pagep);
data = kmap(*++pagep);
off = 0;
}
idx += 8;
len--;
}
kunmap(*pagep);
nidx = node->next;
if (!nidx) {
hfs_dbg(BNODE_MOD, "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_CACHE_SHIFT);
data = kmap(*pagep);
off &= ~PAGE_CACHE_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);
BUG_ON(!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_CACHE_SHIFT];
data = kmap(page);
off &= ~PAGE_CACHE_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);
}