Btrfs: use a btree inode instead of sb_getblk

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-03-28 13:57:48 -04:00 committed by David Woodhouse
parent 5f443fd280
commit d98237b3ed
6 changed files with 174 additions and 24 deletions

View File

@ -233,6 +233,7 @@ struct btrfs_fs_info {
struct btrfs_super_block *disk_super;
struct buffer_head *sb_buffer;
struct super_block *sb;
struct inode *btree_inode;
struct mutex trans_mutex;
struct mutex fs_mutex;
};

View File

@ -1,14 +1,17 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
{
struct btrfs_node *node = btrfs_buffer_node(buf);
if (buf->b_blocknr != btrfs_header_blocknr(&node->header))
if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
BUG();
}
if (root->node && btrfs_header_parentid(&node->header) !=
btrfs_header_parentid(btrfs_buffer_header(root->node))) {
BUG();
@ -16,25 +19,154 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
return 0;
}
struct buffer_head *alloc_tree_block(struct btrfs_root *root, u64 blocknr)
struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
{
return sb_getblk(root->fs_info->sb, blocknr);
struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
int blockbits = root->fs_info->sb->s_blocksize_bits;
unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
struct page *page;
struct buffer_head *bh;
struct buffer_head *head;
struct buffer_head *ret = NULL;
page = find_lock_page(mapping, index);
if (!page)
return NULL;
if (!page_has_buffers(page))
goto out_unlock;
head = page_buffers(page);
bh = head;
do {
if (buffer_mapped(bh) && bh->b_blocknr == blocknr) {
ret = bh;
get_bh(bh);
goto out_unlock;
}
bh = bh->b_this_page;
} while (bh != head);
out_unlock:
unlock_page(page);
page_cache_release(page);
return ret;
}
struct buffer_head *find_tree_block(struct btrfs_root *root, u64 blocknr)
struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
u64 blocknr)
{
return sb_getblk(root->fs_info->sb, blocknr);
struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
int blockbits = root->fs_info->sb->s_blocksize_bits;
unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
struct page *page;
struct buffer_head *bh;
struct buffer_head *head;
struct buffer_head *ret = NULL;
u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
page = grab_cache_page(mapping, index);
if (!page)
return NULL;
wait_on_page_writeback(page);
if (!page_has_buffers(page))
create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
head = page_buffers(page);
bh = head;
do {
if (!buffer_mapped(bh)) {
bh->b_bdev = root->fs_info->sb->s_bdev;
bh->b_blocknr = first_block;
set_buffer_mapped(bh);
}
if (bh->b_blocknr == blocknr) {
ret = bh;
get_bh(bh);
goto out_unlock;
}
bh = bh->b_this_page;
first_block++;
} while (bh != head);
out_unlock:
unlock_page(page);
page_cache_release(page);
return ret;
}
static sector_t max_block(struct block_device *bdev)
{
sector_t retval = ~((sector_t)0);
loff_t sz = i_size_read(bdev->bd_inode);
if (sz) {
unsigned int size = block_size(bdev);
unsigned int sizebits = blksize_bits(size);
retval = (sz >> sizebits);
}
return retval;
}
static int btree_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh, int create)
{
if (iblock >= max_block(inode->i_sb->s_bdev)) {
if (create)
return -EIO;
/*
* for reads, we're just trying to fill a partial page.
* return a hole, they will have to call get_block again
* before they can fill it, and they will get -EIO at that
* time
*/
return 0;
}
bh->b_bdev = inode->i_sb->s_bdev;
bh->b_blocknr = iblock;
set_buffer_mapped(bh);
return 0;
}
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, btree_get_block, wbc);
}
static int btree_readpage(struct file * file, struct page * page)
{
return block_read_full_page(page, btree_get_block);
}
static struct address_space_operations btree_aops = {
.readpage = btree_readpage,
.writepage = btree_writepage,
.sync_page = block_sync_page,
};
struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
{
struct buffer_head *buf = sb_bread(root->fs_info->sb, blocknr);
struct buffer_head *bh = NULL;
if (!buf)
return buf;
if (check_tree_block(root, buf))
bh = btrfs_find_create_tree_block(root, blocknr);
if (!bh)
return bh;
lock_buffer(bh);
if (!buffer_uptodate(bh)) {
get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
submit_bh(READ, bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
goto fail;
} else {
unlock_buffer(bh);
}
if (check_tree_block(root, bh))
BUG();
return buf;
return bh;
fail:
brelse(bh);
return NULL;
}
int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@ -101,11 +233,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
GFP_NOFS);
int ret;
/* FIXME: don't be stupid */
if (!btrfs_super_root(disk_super))
return NULL;
init_bit_radix(&fs_info->pinned_radix);
init_bit_radix(&fs_info->pending_del_radix);
sb_set_blocksize(sb, sb_buffer->b_size);
fs_info->running_transaction = NULL;
fs_info->fs_root = root;
fs_info->tree_root = tree_root;
@ -114,14 +246,30 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->last_inode_alloc = 0;
fs_info->last_inode_alloc_dirid = 0;
fs_info->disk_super = disk_super;
fs_info->sb_buffer = sb_buffer;
fs_info->sb = sb;
fs_info->btree_inode = new_inode(sb);
fs_info->btree_inode->i_ino = 1;
fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
mutex_init(&fs_info->trans_mutex);
mutex_init(&fs_info->fs_mutex);
memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
__setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr);
if (!fs_info->sb_buffer)
return NULL;
brelse(sb_buffer);
sb_buffer = NULL;
disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
fs_info->disk_super = disk_super;
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super));
BUG_ON(!tree_root->node);
@ -137,7 +285,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
ret = find_and_setup_root(disk_super, tree_root, fs_info,
BTRFS_FS_TREE_OBJECTID, root);
BUG_ON(ret);
root->commit_root = root->node;
get_bh(root->node);
root->ref_cows = 1;
@ -191,6 +338,7 @@ int close_ctree(struct btrfs_root *root)
root->fs_info->tree_root->node);
btrfs_block_release(root, root->commit_root);
btrfs_block_release(root, root->fs_info->sb_buffer);
iput(root->fs_info->btree_inode);
kfree(root->fs_info->extent_root);
kfree(root->fs_info->inode_root);
kfree(root->fs_info->tree_root);

View File

@ -21,7 +21,8 @@ static inline struct btrfs_header *btrfs_buffer_header(struct buffer_head *bh)
}
struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr);
struct buffer_head *find_tree_block(struct btrfs_root *root, u64 blocknr);
struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
u64 blocknr);
int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct buffer_head *buf);
int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@ -37,5 +38,5 @@ int close_ctree(struct btrfs_root *root);
void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf);
int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int mkfs(int fd, u64 num_blocks, u32 blocksize);
struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr);
#endif

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@ -172,8 +172,8 @@ static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
struct buffer_head *bh;
if (!pending) {
bh = sb_find_get_block(root->fs_info->sb, blocknr);
if (bh) {
bh = btrfs_find_tree_block(root, blocknr);
if (bh && buffer_uptodate(bh)) {
header = btrfs_buffer_header(bh);
if (btrfs_header_generation(header) ==
root->fs_info->running_transaction->transid) {
@ -291,12 +291,10 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr, u64 num_blocks, int pin)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct buffer_head *t;
int pending_ret;
int ret;
if (root == extent_root) {
t = find_tree_block(root, blocknr);
pin_down_block(root, blocknr, 1);
return 0;
}
@ -482,7 +480,7 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
BUG();
return NULL;
}
buf = find_tree_block(root, ins.objectid);
buf = btrfs_find_create_tree_block(root, ins.objectid);
set_buffer_uptodate(buf);
return buf;
}

View File

@ -474,6 +474,8 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
disk_super = (struct btrfs_super_block *)bh->b_data;
root = open_ctree(sb, bh, disk_super);
sb->s_fs_info = root;
disk_super = root->fs_info->disk_super;
if (!root) {
printk("btrfs: open_ctree failed\n");
return -EIO;
@ -734,15 +736,15 @@ static int btrfs_sync_fs(struct super_block *sb, int wait)
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
root = btrfs_sb(sb);
sb->s_dirt = 0;
if (!wait) {
filemap_flush(sb->s_bdev->bd_inode->i_mapping);
filemap_flush(root->fs_info->btree_inode->i_mapping);
return 0;
}
filemap_write_and_wait(sb->s_bdev->bd_inode->i_mapping);
filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
root = btrfs_sb(sb);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);

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@ -74,7 +74,7 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans,
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
return 0;
}