0f7d52f443
Signed-off-by: Chris Mason <chris.mason@oracle.com>
542 lines
14 KiB
C
542 lines
14 KiB
C
#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/blkdev.h>
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#include <linux/crypto.h>
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#include <linux/scatterlist.h>
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#include <linux/swap.h>
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#include <linux/radix-tree.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#include "btrfs_inode.h"
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static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
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{
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struct btrfs_node *node = btrfs_buffer_node(buf);
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if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
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BUG();
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}
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if (root->node && btrfs_header_parentid(&node->header) !=
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btrfs_header_parentid(btrfs_buffer_header(root->node))) {
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BUG();
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}
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return 0;
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}
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struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
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{
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struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
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int blockbits = root->fs_info->sb->s_blocksize_bits;
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unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
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struct page *page;
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struct buffer_head *bh;
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struct buffer_head *head;
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struct buffer_head *ret = NULL;
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page = find_lock_page(mapping, index);
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if (!page)
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return NULL;
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if (!page_has_buffers(page))
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goto out_unlock;
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head = page_buffers(page);
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bh = head;
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do {
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if (buffer_mapped(bh) && bh->b_blocknr == blocknr) {
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ret = bh;
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get_bh(bh);
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goto out_unlock;
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}
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bh = bh->b_this_page;
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} while (bh != head);
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out_unlock:
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unlock_page(page);
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if (ret) {
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touch_buffer(ret);
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}
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page_cache_release(page);
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return ret;
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}
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struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
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u64 blocknr)
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{
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struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
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int blockbits = root->fs_info->sb->s_blocksize_bits;
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unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
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struct page *page;
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struct buffer_head *bh;
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struct buffer_head *head;
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struct buffer_head *ret = NULL;
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u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
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page = grab_cache_page(mapping, index);
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if (!page)
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return NULL;
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if (!page_has_buffers(page))
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create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
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head = page_buffers(page);
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bh = head;
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do {
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if (!buffer_mapped(bh)) {
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bh->b_bdev = root->fs_info->sb->s_bdev;
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bh->b_blocknr = first_block;
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set_buffer_mapped(bh);
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}
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if (bh->b_blocknr == blocknr) {
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ret = bh;
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get_bh(bh);
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goto out_unlock;
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}
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bh = bh->b_this_page;
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first_block++;
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} while (bh != head);
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out_unlock:
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unlock_page(page);
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if (ret)
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touch_buffer(ret);
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page_cache_release(page);
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return ret;
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}
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static sector_t max_block(struct block_device *bdev)
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{
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sector_t retval = ~((sector_t)0);
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loff_t sz = i_size_read(bdev->bd_inode);
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if (sz) {
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unsigned int size = block_size(bdev);
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unsigned int sizebits = blksize_bits(size);
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retval = (sz >> sizebits);
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}
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return retval;
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}
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static int btree_get_block(struct inode *inode, sector_t iblock,
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struct buffer_head *bh, int create)
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{
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if (iblock >= max_block(inode->i_sb->s_bdev)) {
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if (create)
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return -EIO;
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/*
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* for reads, we're just trying to fill a partial page.
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* return a hole, they will have to call get_block again
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* before they can fill it, and they will get -EIO at that
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* time
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*/
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return 0;
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}
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bh->b_bdev = inode->i_sb->s_bdev;
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bh->b_blocknr = iblock;
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set_buffer_mapped(bh);
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return 0;
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}
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int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
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char *result)
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{
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struct scatterlist sg;
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struct crypto_hash *tfm = root->fs_info->hash_tfm;
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struct hash_desc desc;
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int ret;
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desc.tfm = tfm;
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desc.flags = 0;
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sg_init_one(&sg, data, len);
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spin_lock(&root->fs_info->hash_lock);
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ret = crypto_hash_digest(&desc, &sg, 1, result);
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spin_unlock(&root->fs_info->hash_lock);
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if (ret) {
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printk("sha256 digest failed\n");
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}
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return ret;
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}
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static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
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int verify)
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{
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char result[BTRFS_CSUM_SIZE];
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int ret;
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struct btrfs_node *node;
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ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
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bh->b_size - BTRFS_CSUM_SIZE, result);
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if (ret)
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return ret;
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if (verify) {
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if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
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printk("checksum verify failed on %lu\n",
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bh->b_blocknr);
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return 1;
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}
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} else {
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node = btrfs_buffer_node(bh);
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memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
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}
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return 0;
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}
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static int btree_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct buffer_head *bh;
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struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
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struct buffer_head *head;
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if (!page_has_buffers(page)) {
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create_empty_buffers(page, root->fs_info->sb->s_blocksize,
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(1 << BH_Dirty)|(1 << BH_Uptodate));
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}
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head = page_buffers(page);
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bh = head;
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do {
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if (buffer_dirty(bh))
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csum_tree_block(root, bh, 0);
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bh = bh->b_this_page;
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} while (bh != head);
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return block_write_full_page(page, btree_get_block, wbc);
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}
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static int btree_readpage(struct file * file, struct page * page)
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{
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return block_read_full_page(page, btree_get_block);
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}
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static struct address_space_operations btree_aops = {
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.readpage = btree_readpage,
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.writepage = btree_writepage,
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.sync_page = block_sync_page,
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};
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struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
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{
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struct buffer_head *bh = NULL;
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bh = btrfs_find_create_tree_block(root, blocknr);
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if (!bh)
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return bh;
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if (buffer_uptodate(bh))
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goto uptodate;
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lock_buffer(bh);
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if (!buffer_uptodate(bh)) {
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get_bh(bh);
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bh->b_end_io = end_buffer_read_sync;
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submit_bh(READ, bh);
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wait_on_buffer(bh);
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if (!buffer_uptodate(bh))
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goto fail;
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csum_tree_block(root, bh, 1);
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} else {
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unlock_buffer(bh);
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}
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uptodate:
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if (check_tree_block(root, bh))
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BUG();
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return bh;
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fail:
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brelse(bh);
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return NULL;
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}
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int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct buffer_head *buf)
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{
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WARN_ON(atomic_read(&buf->b_count) == 0);
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mark_buffer_dirty(buf);
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return 0;
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}
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int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct buffer_head *buf)
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{
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WARN_ON(atomic_read(&buf->b_count) == 0);
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clear_buffer_dirty(buf);
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return 0;
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}
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static int __setup_root(int blocksize,
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struct btrfs_root *root,
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struct btrfs_fs_info *fs_info,
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u64 objectid)
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{
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root->node = NULL;
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root->inode = NULL;
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root->commit_root = NULL;
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root->blocksize = blocksize;
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root->ref_cows = 0;
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root->fs_info = fs_info;
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root->objectid = objectid;
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root->last_trans = 0;
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memset(&root->root_key, 0, sizeof(root->root_key));
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memset(&root->root_item, 0, sizeof(root->root_item));
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return 0;
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}
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static int find_and_setup_root(int blocksize,
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struct btrfs_root *tree_root,
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struct btrfs_fs_info *fs_info,
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u64 objectid,
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struct btrfs_root *root)
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{
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int ret;
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__setup_root(blocksize, root, fs_info, objectid);
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ret = btrfs_find_last_root(tree_root, objectid,
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&root->root_item, &root->root_key);
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BUG_ON(ret);
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root->node = read_tree_block(root,
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btrfs_root_blocknr(&root->root_item));
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BUG_ON(!root->node);
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return 0;
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}
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struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
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struct btrfs_key *location)
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{
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struct btrfs_root *root;
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struct btrfs_root *tree_root = fs_info->tree_root;
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struct btrfs_path *path;
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struct btrfs_leaf *l;
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int ret = 0;
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printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
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root = kmalloc(sizeof(*root), GFP_NOFS);
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if (!root) {
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printk("failed1\n");
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return ERR_PTR(-ENOMEM);
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}
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if (location->offset == (u64)-1) {
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ret = find_and_setup_root(fs_info->sb->s_blocksize,
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fs_info->tree_root, fs_info,
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location->objectid, root);
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if (ret) {
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printk("failed2\n");
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kfree(root);
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return ERR_PTR(ret);
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}
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goto insert;
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}
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__setup_root(fs_info->sb->s_blocksize, root, fs_info,
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location->objectid);
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path = btrfs_alloc_path();
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BUG_ON(!path);
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ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
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if (ret != 0) {
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printk("internal search_slot gives us %d\n", ret);
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if (ret > 0)
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ret = -ENOENT;
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goto out;
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}
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l = btrfs_buffer_leaf(path->nodes[0]);
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memcpy(&root->root_item,
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btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
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sizeof(root->root_item));
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memcpy(&root->root_key, location, sizeof(*location));
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ret = 0;
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out:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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if (ret) {
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kfree(root);
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return ERR_PTR(ret);
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}
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root->node = read_tree_block(root,
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btrfs_root_blocknr(&root->root_item));
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BUG_ON(!root->node);
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insert:
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printk("inserting %p\n", root);
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root->ref_cows = 1;
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ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root,
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root);
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if (ret) {
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printk("radix_tree_insert gives us %d\n", ret);
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brelse(root->node);
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kfree(root);
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return ERR_PTR(ret);
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}
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printk("all worked\n");
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return root;
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}
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struct btrfs_root *open_ctree(struct super_block *sb)
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{
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struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
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GFP_NOFS);
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struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
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GFP_NOFS);
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struct btrfs_root *inode_root = kmalloc(sizeof(struct btrfs_root),
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GFP_NOFS);
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struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
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GFP_NOFS);
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int ret;
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struct btrfs_super_block *disk_super;
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init_bit_radix(&fs_info->pinned_radix);
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init_bit_radix(&fs_info->pending_del_radix);
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INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
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sb_set_blocksize(sb, 4096);
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fs_info->running_transaction = NULL;
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fs_info->tree_root = tree_root;
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fs_info->extent_root = extent_root;
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fs_info->inode_root = inode_root;
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fs_info->last_inode_alloc = 0;
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fs_info->highest_inode = 0;
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fs_info->sb = sb;
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fs_info->btree_inode = new_inode(sb);
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fs_info->btree_inode->i_ino = 1;
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fs_info->btree_inode->i_nlink = 1;
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fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
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fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
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BTRFS_I(fs_info->btree_inode)->root = tree_root;
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memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
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sizeof(struct btrfs_key));
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insert_inode_hash(fs_info->btree_inode);
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mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
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fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
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spin_lock_init(&fs_info->hash_lock);
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if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
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printk("failed to allocate sha256 hash\n");
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return NULL;
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}
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mutex_init(&fs_info->trans_mutex);
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mutex_init(&fs_info->fs_mutex);
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memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
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memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
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__setup_root(sb->s_blocksize, tree_root,
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fs_info, BTRFS_ROOT_TREE_OBJECTID);
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fs_info->sb_buffer = read_tree_block(tree_root,
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BTRFS_SUPER_INFO_OFFSET /
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sb->s_blocksize);
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if (!fs_info->sb_buffer)
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return NULL;
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disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
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if (!btrfs_super_root(disk_super))
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return NULL;
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fs_info->disk_super = disk_super;
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tree_root->node = read_tree_block(tree_root,
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btrfs_super_root(disk_super));
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BUG_ON(!tree_root->node);
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mutex_lock(&fs_info->fs_mutex);
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ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
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BTRFS_EXTENT_TREE_OBJECTID, extent_root);
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BUG_ON(ret);
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ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
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BTRFS_INODE_MAP_OBJECTID, inode_root);
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BUG_ON(ret);
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fs_info->generation = btrfs_super_generation(disk_super) + 1;
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ret = btrfs_find_highest_inode(tree_root, &fs_info->last_inode_alloc);
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if (ret == 0)
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fs_info->highest_inode = fs_info->last_inode_alloc;
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memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
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kobj_set_kset_s(fs_info, btrfs_subsys);
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kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
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kobject_register(&fs_info->kobj);
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mutex_unlock(&fs_info->fs_mutex);
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return tree_root;
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}
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int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
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*root)
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{
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struct buffer_head *bh = root->fs_info->sb_buffer;
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btrfs_set_super_root(root->fs_info->disk_super,
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root->fs_info->tree_root->node->b_blocknr);
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lock_buffer(bh);
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WARN_ON(atomic_read(&bh->b_count) < 1);
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clear_buffer_dirty(bh);
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csum_tree_block(root, bh, 0);
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bh->b_end_io = end_buffer_write_sync;
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get_bh(bh);
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submit_bh(WRITE, bh);
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wait_on_buffer(bh);
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if (!buffer_uptodate(bh)) {
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WARN_ON(1);
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return -EIO;
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}
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return 0;
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}
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int del_fs_roots(struct btrfs_fs_info *fs_info)
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{
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int ret;
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struct btrfs_root *gang[8];
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int i;
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while(1) {
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ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
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(void **)gang, 0,
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ARRAY_SIZE(gang));
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if (!ret)
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break;
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for (i = 0; i < ret; i++) {
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radix_tree_delete(&fs_info->fs_roots_radix,
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(unsigned long)gang[i]);
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if (gang[i]->inode)
|
|
iput(gang[i]->inode);
|
|
else
|
|
printk("no inode for root %p\n", gang[i]);
|
|
if (gang[i]->node)
|
|
brelse(gang[i]->node);
|
|
if (gang[i]->commit_root)
|
|
brelse(gang[i]->commit_root);
|
|
kfree(gang[i]);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int close_ctree(struct btrfs_root *root)
|
|
{
|
|
int ret;
|
|
struct btrfs_trans_handle *trans;
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
|
|
mutex_lock(&fs_info->fs_mutex);
|
|
trans = btrfs_start_transaction(root, 1);
|
|
btrfs_commit_transaction(trans, root);
|
|
/* run commit again to drop the original snapshot */
|
|
trans = btrfs_start_transaction(root, 1);
|
|
btrfs_commit_transaction(trans, root);
|
|
ret = btrfs_write_and_wait_transaction(NULL, root);
|
|
BUG_ON(ret);
|
|
write_ctree_super(NULL, root);
|
|
mutex_unlock(&fs_info->fs_mutex);
|
|
|
|
if (fs_info->extent_root->node)
|
|
btrfs_block_release(fs_info->extent_root,
|
|
fs_info->extent_root->node);
|
|
if (fs_info->inode_root->node)
|
|
btrfs_block_release(fs_info->inode_root,
|
|
fs_info->inode_root->node);
|
|
if (fs_info->tree_root->node)
|
|
btrfs_block_release(fs_info->tree_root,
|
|
fs_info->tree_root->node);
|
|
btrfs_block_release(root, fs_info->sb_buffer);
|
|
crypto_free_hash(fs_info->hash_tfm);
|
|
truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
|
|
iput(fs_info->btree_inode);
|
|
del_fs_roots(fs_info);
|
|
kfree(fs_info->extent_root);
|
|
kfree(fs_info->inode_root);
|
|
kfree(fs_info->tree_root);
|
|
kobject_unregister(&fs_info->kobj);
|
|
return 0;
|
|
}
|
|
|
|
void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
|
|
{
|
|
brelse(buf);
|
|
}
|
|
|