linux/fs/hfs/bnode.c

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/*
* linux/fs/hfs/bnode.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handle basic btree node operations
*/
#include <linux/pagemap.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/swap.h>
#include "btree.h"
void hfs_bnode_read(struct hfs_bnode *node, void *buf,
int off, int len)
{
struct page *page;
off += node->page_offset;
page = node->page[0];
memcpy(buf, kmap(page) + off, len);
kunmap(page);
}
u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
{
__be16 data;
// optimize later...
hfs_bnode_read(node, &data, off, 2);
return be16_to_cpu(data);
}
u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
{
u8 data;
// optimize later...
hfs_bnode_read(node, &data, off, 1);
return data;
}
void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
{
struct hfs_btree *tree;
int key_len;
tree = node->tree;
if (node->type == HFS_NODE_LEAF ||
tree->attributes & HFS_TREE_VARIDXKEYS)
key_len = hfs_bnode_read_u8(node, off) + 1;
else
key_len = tree->max_key_len + 1;
hfs_bnode_read(node, key, off, key_len);
}
void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
{
struct page *page;
off += node->page_offset;
page = node->page[0];
memcpy(kmap(page) + off, buf, len);
kunmap(page);
set_page_dirty(page);
}
void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
{
__be16 v = cpu_to_be16(data);
// optimize later...
hfs_bnode_write(node, &v, off, 2);
}
void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
{
// optimize later...
hfs_bnode_write(node, &data, off, 1);
}
void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
{
struct page *page;
off += node->page_offset;
page = node->page[0];
memset(kmap(page) + off, 0, len);
kunmap(page);
set_page_dirty(page);
}
void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
struct hfs_bnode *src_node, int src, int len)
{
struct hfs_btree *tree;
struct page *src_page, *dst_page;
hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
if (!len)
return;
tree = src_node->tree;
src += src_node->page_offset;
dst += dst_node->page_offset;
src_page = src_node->page[0];
dst_page = dst_node->page[0];
memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
kunmap(src_page);
kunmap(dst_page);
set_page_dirty(dst_page);
}
void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
{
struct page *page;
void *ptr;
hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
if (!len)
return;
src += node->page_offset;
dst += node->page_offset;
page = node->page[0];
ptr = kmap(page);
memmove(ptr + dst, ptr + src, len);
kunmap(page);
set_page_dirty(page);
}
void hfs_bnode_dump(struct hfs_bnode *node)
{
struct hfs_bnode_desc desc;
__be32 cnid;
int i, off, key_off;
hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
hfs_bnode_read(node, &desc, 0, sizeof(desc));
hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
desc.type, desc.height, be16_to_cpu(desc.num_recs));
off = node->tree->node_size - 2;
for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
key_off = hfs_bnode_read_u16(node, off);
hfs_dbg_cont(BNODE_MOD, " %d", key_off);
if (i && node->type == HFS_NODE_INDEX) {
int tmp;
if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
else
tmp = node->tree->max_key_len + 1;
hfs_dbg_cont(BNODE_MOD, " (%d,%d",
tmp, hfs_bnode_read_u8(node, key_off));
hfs_bnode_read(node, &cnid, key_off + tmp, 4);
hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
} else if (i && node->type == HFS_NODE_LEAF) {
int tmp;
tmp = hfs_bnode_read_u8(node, key_off);
hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
}
}
hfs_dbg_cont(BNODE_MOD, "\n");
}
void hfs_bnode_unlink(struct hfs_bnode *node)
{
struct hfs_btree *tree;
struct hfs_bnode *tmp;
__be32 cnid;
tree = node->tree;
if (node->prev) {
tmp = hfs_bnode_find(tree, node->prev);
if (IS_ERR(tmp))
return;
tmp->next = node->next;
cnid = cpu_to_be32(tmp->next);
hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
hfs_bnode_put(tmp);
} else if (node->type == HFS_NODE_LEAF)
tree->leaf_head = node->next;
if (node->next) {
tmp = hfs_bnode_find(tree, node->next);
if (IS_ERR(tmp))
return;
tmp->prev = node->prev;
cnid = cpu_to_be32(tmp->prev);
hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
hfs_bnode_put(tmp);
} else if (node->type == HFS_NODE_LEAF)
tree->leaf_tail = node->prev;
// move down?
if (!node->prev && !node->next) {
printk(KERN_DEBUG "hfs_btree_del_level\n");
}
if (!node->parent) {
tree->root = 0;
tree->depth = 0;
}
set_bit(HFS_BNODE_DELETED, &node->flags);
}
static inline int hfs_bnode_hash(u32 num)
{
num = (num >> 16) + num;
num += num >> 8;
return num & (NODE_HASH_SIZE - 1);
}
struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
{
struct hfs_bnode *node;
if (cnid >= tree->node_count) {
pr_err("request for non-existent node %d in B*Tree\n", cnid);
return NULL;
}
for (node = tree->node_hash[hfs_bnode_hash(cnid)];
node; node = node->next_hash) {
if (node->this == cnid) {
return node;
}
}
return NULL;
}
static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
{
struct super_block *sb;
struct hfs_bnode *node, *node2;
struct address_space *mapping;
struct page *page;
int size, block, i, hash;
loff_t off;
if (cnid >= tree->node_count) {
pr_err("request for non-existent node %d in B*Tree\n", cnid);
return NULL;
}
sb = tree->inode->i_sb;
size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
sizeof(struct page *);
node = kzalloc(size, GFP_KERNEL);
if (!node)
return NULL;
node->tree = tree;
node->this = cnid;
set_bit(HFS_BNODE_NEW, &node->flags);
atomic_set(&node->refcnt, 1);
hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
node->tree->cnid, node->this);
init_waitqueue_head(&node->lock_wq);
spin_lock(&tree->hash_lock);
node2 = hfs_bnode_findhash(tree, cnid);
if (!node2) {
hash = hfs_bnode_hash(cnid);
node->next_hash = tree->node_hash[hash];
tree->node_hash[hash] = node;
tree->node_hash_cnt++;
} else {
spin_unlock(&tree->hash_lock);
kfree(node);
wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
return node2;
}
spin_unlock(&tree->hash_lock);
mapping = tree->inode->i_mapping;
off = (loff_t)cnid * tree->node_size;
block = off >> PAGE_CACHE_SHIFT;
node->page_offset = off & ~PAGE_CACHE_MASK;
for (i = 0; i < tree->pages_per_bnode; i++) {
page = read_mapping_page(mapping, block++, NULL);
if (IS_ERR(page))
goto fail;
if (PageError(page)) {
page_cache_release(page);
goto fail;
}
page_cache_release(page);
node->page[i] = page;
}
return node;
fail:
set_bit(HFS_BNODE_ERROR, &node->flags);
return node;
}
void hfs_bnode_unhash(struct hfs_bnode *node)
{
struct hfs_bnode **p;
hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
node->tree->cnid, node->this, atomic_read(&node->refcnt));
for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
*p && *p != node; p = &(*p)->next_hash)
;
BUG_ON(!*p);
*p = node->next_hash;
node->tree->node_hash_cnt--;
}
/* Load a particular node out of a tree */
struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
{
struct hfs_bnode *node;
struct hfs_bnode_desc *desc;
int i, rec_off, off, next_off;
int entry_size, key_size;
spin_lock(&tree->hash_lock);
node = hfs_bnode_findhash(tree, num);
if (node) {
hfs_bnode_get(node);
spin_unlock(&tree->hash_lock);
wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
if (test_bit(HFS_BNODE_ERROR, &node->flags))
goto node_error;
return node;
}
spin_unlock(&tree->hash_lock);
node = __hfs_bnode_create(tree, num);
if (!node)
return ERR_PTR(-ENOMEM);
if (test_bit(HFS_BNODE_ERROR, &node->flags))
goto node_error;
if (!test_bit(HFS_BNODE_NEW, &node->flags))
return node;
desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
node->prev = be32_to_cpu(desc->prev);
node->next = be32_to_cpu(desc->next);
node->num_recs = be16_to_cpu(desc->num_recs);
node->type = desc->type;
node->height = desc->height;
kunmap(node->page[0]);
switch (node->type) {
case HFS_NODE_HEADER:
case HFS_NODE_MAP:
if (node->height != 0)
goto node_error;
break;
case HFS_NODE_LEAF:
if (node->height != 1)
goto node_error;
break;
case HFS_NODE_INDEX:
if (node->height <= 1 || node->height > tree->depth)
goto node_error;
break;
default:
goto node_error;
}
rec_off = tree->node_size - 2;
off = hfs_bnode_read_u16(node, rec_off);
if (off != sizeof(struct hfs_bnode_desc))
goto node_error;
for (i = 1; i <= node->num_recs; off = next_off, i++) {
rec_off -= 2;
next_off = hfs_bnode_read_u16(node, rec_off);
if (next_off <= off ||
next_off > tree->node_size ||
next_off & 1)
goto node_error;
entry_size = next_off - off;
if (node->type != HFS_NODE_INDEX &&
node->type != HFS_NODE_LEAF)
continue;
key_size = hfs_bnode_read_u8(node, off) + 1;
if (key_size >= entry_size /*|| key_size & 1*/)
goto node_error;
}
clear_bit(HFS_BNODE_NEW, &node->flags);
wake_up(&node->lock_wq);
return node;
node_error:
set_bit(HFS_BNODE_ERROR, &node->flags);
clear_bit(HFS_BNODE_NEW, &node->flags);
wake_up(&node->lock_wq);
hfs_bnode_put(node);
return ERR_PTR(-EIO);
}
void hfs_bnode_free(struct hfs_bnode *node)
{
//int i;
//for (i = 0; i < node->tree->pages_per_bnode; i++)
// if (node->page[i])
// page_cache_release(node->page[i]);
kfree(node);
}
struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
{
struct hfs_bnode *node;
struct page **pagep;
int i;
spin_lock(&tree->hash_lock);
node = hfs_bnode_findhash(tree, num);
spin_unlock(&tree->hash_lock);
if (node) {
pr_crit("new node %u already hashed?\n", num);
WARN_ON(1);
return node;
}
node = __hfs_bnode_create(tree, num);
if (!node)
return ERR_PTR(-ENOMEM);
if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
hfs_bnode_put(node);
return ERR_PTR(-EIO);
}
pagep = node->page;
memset(kmap(*pagep) + node->page_offset, 0,
min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
set_page_dirty(*pagep);
kunmap(*pagep);
for (i = 1; i < tree->pages_per_bnode; i++) {
memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
set_page_dirty(*pagep);
kunmap(*pagep);
}
clear_bit(HFS_BNODE_NEW, &node->flags);
wake_up(&node->lock_wq);
return node;
}
void hfs_bnode_get(struct hfs_bnode *node)
{
if (node) {
atomic_inc(&node->refcnt);
hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
node->tree->cnid, node->this,
atomic_read(&node->refcnt));
}
}
/* Dispose of resources used by a node */
void hfs_bnode_put(struct hfs_bnode *node)
{
if (node) {
struct hfs_btree *tree = node->tree;
int i;
hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
node->tree->cnid, node->this,
atomic_read(&node->refcnt));
BUG_ON(!atomic_read(&node->refcnt));
if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
return;
for (i = 0; i < tree->pages_per_bnode; i++) {
if (!node->page[i])
continue;
mark_page_accessed(node->page[i]);
}
if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
hfs_bnode_unhash(node);
spin_unlock(&tree->hash_lock);
hfs_bmap_free(node);
hfs_bnode_free(node);
return;
}
spin_unlock(&tree->hash_lock);
}
}