1
linux/fs/btrfs/disk-io.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/crc32c.h>
#include <linux/scatterlist.h>
#include <linux/swap.h>
#include <linux/radix-tree.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> // for block_sync_page
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "volumes.h"
#include "print-tree.h"
#if 0
static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
{
if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
(unsigned long long)extent_buffer_blocknr(buf),
(unsigned long long)btrfs_header_blocknr(buf));
return 1;
}
return 0;
}
#endif
static struct extent_io_ops btree_extent_io_ops;
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_buffer *eb;
eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
bytenr, blocksize, GFP_NOFS);
return eb;
}
struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_buffer *eb;
eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
bytenr, blocksize, NULL, GFP_NOFS);
return eb;
}
struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
size_t page_offset, u64 start, u64 len,
int create)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
int ret;
again:
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
spin_unlock(&em_tree->lock);
if (em) {
goto out;
}
em = alloc_extent_map(GFP_NOFS);
if (!em) {
em = ERR_PTR(-ENOMEM);
goto out;
}
em->start = 0;
em->len = i_size_read(inode);
em->block_start = 0;
em->bdev = inode->i_sb->s_bdev;
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
spin_unlock(&em_tree->lock);
if (ret == -EEXIST) {
free_extent_map(em);
em = NULL;
goto again;
} else if (ret) {
em = ERR_PTR(ret);
}
out:
return em;
}
u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
{
return crc32c(seed, data, len);
}
void btrfs_csum_final(u32 crc, char *result)
{
*(__le32 *)result = ~cpu_to_le32(crc);
}
static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify)
{
char result[BTRFS_CRC32_SIZE];
unsigned long len;
unsigned long cur_len;
unsigned long offset = BTRFS_CSUM_SIZE;
char *map_token = NULL;
char *kaddr;
unsigned long map_start;
unsigned long map_len;
int err;
u32 crc = ~(u32)0;
len = buf->len - offset;
while(len > 0) {
err = map_private_extent_buffer(buf, offset, 32,
&map_token, &kaddr,
&map_start, &map_len, KM_USER0);
if (err) {
printk("failed to map extent buffer! %lu\n",
offset);
return 1;
}
cur_len = min(len, map_len - (offset - map_start));
crc = btrfs_csum_data(root, kaddr + offset - map_start,
crc, cur_len);
len -= cur_len;
offset += cur_len;
unmap_extent_buffer(buf, map_token, KM_USER0);
}
btrfs_csum_final(crc, result);
if (verify) {
int from_this_trans = 0;
if (root->fs_info->running_transaction &&
btrfs_header_generation(buf) ==
root->fs_info->running_transaction->transid)
from_this_trans = 1;
/* FIXME, this is not good */
if (from_this_trans == 0 &&
memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
u32 val;
u32 found = 0;
memcpy(&found, result, BTRFS_CRC32_SIZE);
read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
printk("btrfs: %s checksum verify failed on %llu "
"wanted %X found %X from_this_trans %d\n",
root->fs_info->sb->s_id,
buf->start, val, found, from_this_trans);
return 1;
}
} else {
write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
}
return 0;
}
int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
{
struct extent_io_tree *tree;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 found_start;
int found_level;
unsigned long len;
struct extent_buffer *eb;
tree = &BTRFS_I(page->mapping->host)->io_tree;
if (page->private == EXTENT_PAGE_PRIVATE)
goto out;
if (!page->private)
goto out;
len = page->private >> 2;
if (len == 0) {
WARN_ON(1);
}
eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1,
btree_get_extent);
btrfs_clear_buffer_defrag(eb);
found_start = btrfs_header_bytenr(eb);
if (found_start != start) {
printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
start, found_start, len);
WARN_ON(1);
goto err;
}
if (eb->first_page != page) {
printk("bad first page %lu %lu\n", eb->first_page->index,
page->index);
WARN_ON(1);
goto err;
}
if (!PageUptodate(page)) {
printk("csum not up to date page %lu\n", page->index);
WARN_ON(1);
goto err;
}
found_level = btrfs_header_level(eb);
csum_tree_block(root, eb, 0);
err:
free_extent_buffer(eb);
out:
return 0;
}
static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
{
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
csum_dirty_buffer(root, page);
return 0;
}
static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 offset;
offset = bio->bi_sector << 9;
if (offset == BTRFS_SUPER_INFO_OFFSET) {
bio->bi_bdev = root->fs_info->sb->s_bdev;
submit_bio(rw, bio);
return 0;
}
return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio);
}
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_write_full_page(tree, page, btree_get_extent, wbc);
}
static int btree_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
if (wbc->sync_mode == WB_SYNC_NONE) {
u64 num_dirty;
u64 start = 0;
unsigned long thresh = 96 * 1024 * 1024;
if (wbc->for_kupdate)
return 0;
if (current_is_pdflush()) {
thresh = 96 * 1024 * 1024;
} else {
thresh = 8 * 1024 * 1024;
}
num_dirty = count_range_bits(tree, &start, (u64)-1,
thresh, EXTENT_DIRTY);
if (num_dirty < thresh) {
return 0;
}
}
return extent_writepages(tree, mapping, btree_get_extent, wbc);
}
int btree_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btree_get_extent);
}
static int btree_releasepage(struct page *page, gfp_t gfp_flags)
{
struct extent_io_tree *tree;
struct extent_map_tree *map;
int ret;
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(map, tree, page, gfp_flags);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
return ret;
}
static void btree_invalidatepage(struct page *page, unsigned long offset)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
extent_invalidatepage(tree, page, offset);
btree_releasepage(page, GFP_NOFS);
}
#if 0
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
struct buffer_head *bh;
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
struct buffer_head *head;
if (!page_has_buffers(page)) {
create_empty_buffers(page, root->fs_info->sb->s_blocksize,
(1 << BH_Dirty)|(1 << BH_Uptodate));
}
head = page_buffers(page);
bh = head;
do {
if (buffer_dirty(bh))
csum_tree_block(root, bh, 0);
bh = bh->b_this_page;
} while (bh != head);
return block_write_full_page(page, btree_get_block, wbc);
}
#endif
static struct address_space_operations btree_aops = {
.readpage = btree_readpage,
.writepage = btree_writepage,
.writepages = btree_writepages,
.releasepage = btree_releasepage,
.invalidatepage = btree_invalidatepage,
.sync_page = block_sync_page,
};
int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
{
struct extent_buffer *buf = NULL;
struct inode *btree_inode = root->fs_info->btree_inode;
int ret = 0;
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return 0;
read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, 0, btree_get_extent);
free_extent_buffer(buf);
return ret;
}
static int close_all_devices(struct btrfs_fs_info *fs_info)
{
struct list_head *list;
struct list_head *next;
struct btrfs_device *device;
list = &fs_info->fs_devices->devices;
list_for_each(next, list) {
device = list_entry(next, struct btrfs_device, dev_list);
if (device->bdev && device->bdev != fs_info->sb->s_bdev)
close_bdev_excl(device->bdev);
device->bdev = NULL;
}
return 0;
}
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize)
{
struct extent_buffer *buf = NULL;
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_io_tree *io_tree;
u64 end;
int ret;
io_tree = &BTRFS_I(btree_inode)->io_tree;
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return NULL;
read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1,
btree_get_extent);
if (buf->flags & EXTENT_CSUM)
return buf;
end = buf->start + PAGE_CACHE_SIZE - 1;
if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
buf->flags |= EXTENT_CSUM;
return buf;
}
lock_extent(io_tree, buf->start, end, GFP_NOFS);
if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
buf->flags |= EXTENT_CSUM;
goto out_unlock;
}
ret = csum_tree_block(root, buf, 1);
set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
out_unlock:
unlock_extent(io_tree, buf->start, end, GFP_NOFS);
return buf;
}
int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf)
{
struct inode *btree_inode = root->fs_info->btree_inode;
if (btrfs_header_generation(buf) ==
root->fs_info->running_transaction->transid)
clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
buf);
return 0;
}
int wait_on_tree_block_writeback(struct btrfs_root *root,
struct extent_buffer *buf)
{
struct inode *btree_inode = root->fs_info->btree_inode;
wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
buf);
return 0;
}
static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
u32 stripesize, struct btrfs_root *root,
struct btrfs_fs_info *fs_info,
u64 objectid)
{
root->node = NULL;
root->inode = NULL;
root->commit_root = NULL;
root->sectorsize = sectorsize;
root->nodesize = nodesize;
root->leafsize = leafsize;
root->stripesize = stripesize;
root->ref_cows = 0;
root->track_dirty = 0;
root->fs_info = fs_info;
root->objectid = objectid;
root->last_trans = 0;
root->highest_inode = 0;
root->last_inode_alloc = 0;
root->name = NULL;
root->in_sysfs = 0;
INIT_LIST_HEAD(&root->dirty_list);
memset(&root->root_key, 0, sizeof(root->root_key));
memset(&root->root_item, 0, sizeof(root->root_item));
memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
memset(&root->root_kobj, 0, sizeof(root->root_kobj));
init_completion(&root->kobj_unregister);
root->defrag_running = 0;
root->defrag_level = 0;
root->root_key.objectid = objectid;
return 0;
}
static int find_and_setup_root(struct btrfs_root *tree_root,
struct btrfs_fs_info *fs_info,
u64 objectid,
struct btrfs_root *root)
{
int ret;
u32 blocksize;
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
root, fs_info, objectid);
ret = btrfs_find_last_root(tree_root, objectid,
&root->root_item, &root->root_key);
BUG_ON(ret);
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize);
BUG_ON(!root->node);
return 0;
}
struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
struct btrfs_key *location)
{
struct btrfs_root *root;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_path *path;
struct extent_buffer *l;
u64 highest_inode;
u32 blocksize;
int ret = 0;
root = kzalloc(sizeof(*root), GFP_NOFS);
if (!root)
return ERR_PTR(-ENOMEM);
if (location->offset == (u64)-1) {
ret = find_and_setup_root(tree_root, fs_info,
location->objectid, root);
if (ret) {
kfree(root);
return ERR_PTR(ret);
}
goto insert;
}
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
root, fs_info, location->objectid);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
if (ret != 0) {
if (ret > 0)
ret = -ENOENT;
goto out;
}
l = path->nodes[0];
read_extent_buffer(l, &root->root_item,
btrfs_item_ptr_offset(l, path->slots[0]),
sizeof(root->root_item));
memcpy(&root->root_key, location, sizeof(*location));
ret = 0;
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
if (ret) {
kfree(root);
return ERR_PTR(ret);
}
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize);
BUG_ON(!root->node);
insert:
root->ref_cows = 1;
ret = btrfs_find_highest_inode(root, &highest_inode);
if (ret == 0) {
root->highest_inode = highest_inode;
root->last_inode_alloc = highest_inode;
}
return root;
}
struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
u64 root_objectid)
{
struct btrfs_root *root;
if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
return fs_info->tree_root;
if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
return fs_info->extent_root;
root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)root_objectid);
return root;
}
struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
struct btrfs_key *location)
{
struct btrfs_root *root;
int ret;
if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
return fs_info->tree_root;
if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
return fs_info->extent_root;
root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)location->objectid);
if (root)
return root;
root = btrfs_read_fs_root_no_radix(fs_info, location);
if (IS_ERR(root))
return root;
ret = radix_tree_insert(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
root);
if (ret) {
free_extent_buffer(root->node);
kfree(root);
return ERR_PTR(ret);
}
ret = btrfs_find_dead_roots(fs_info->tree_root,
root->root_key.objectid, root);
BUG_ON(ret);
return root;
}
struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
struct btrfs_key *location,
const char *name, int namelen)
{
struct btrfs_root *root;
int ret;
root = btrfs_read_fs_root_no_name(fs_info, location);
if (!root)
return NULL;
if (root->in_sysfs)
return root;
ret = btrfs_set_root_name(root, name, namelen);
if (ret) {
free_extent_buffer(root->node);
kfree(root);
return ERR_PTR(ret);
}
ret = btrfs_sysfs_add_root(root);
if (ret) {
free_extent_buffer(root->node);
kfree(root->name);
kfree(root);
return ERR_PTR(ret);
}
root->in_sysfs = 1;
return root;
}
#if 0
static int add_hasher(struct btrfs_fs_info *info, char *type) {
struct btrfs_hasher *hasher;
hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
if (!hasher)
return -ENOMEM;
hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
if (!hasher->hash_tfm) {
kfree(hasher);
return -EINVAL;
}
spin_lock(&info->hash_lock);
list_add(&hasher->list, &info->hashers);
spin_unlock(&info->hash_lock);
return 0;
}
#endif
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices)
{
u32 sectorsize;
u32 nodesize;
u32 leafsize;
u32 blocksize;
u32 stripesize;
struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
GFP_NOFS);
struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
int ret;
int err = -EIO;
struct btrfs_super_block *disk_super;
if (!extent_root || !tree_root || !fs_info) {
err = -ENOMEM;
goto fail;
}
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
INIT_LIST_HEAD(&fs_info->trans_list);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->hashers);
spin_lock_init(&fs_info->hash_lock);
spin_lock_init(&fs_info->delalloc_lock);
spin_lock_init(&fs_info->new_trans_lock);
memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
init_completion(&fs_info->kobj_unregister);
sb_set_blocksize(sb, 4096);
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = 0;
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
fs_info->chunk_root = chunk_root;
fs_info->dev_root = dev_root;
fs_info->fs_devices = fs_devices;
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
INIT_LIST_HEAD(&fs_info->space_info);
btrfs_mapping_init(&fs_info->mapping_tree);
fs_info->sb = sb;
fs_info->throttles = 0;
fs_info->mount_opt = 0;
fs_info->max_extent = (u64)-1;
fs_info->max_inline = 8192 * 1024;
fs_info->delalloc_bytes = 0;
fs_info->btree_inode = new_inode(sb);
fs_info->btree_inode->i_ino = 1;
fs_info->btree_inode->i_nlink = 1;
fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
fs_info->btree_inode->i_mapping,
GFP_NOFS);
extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
GFP_NOFS);
BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
extent_io_tree_init(&fs_info->free_space_cache,
fs_info->btree_inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&fs_info->block_group_cache,
fs_info->btree_inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&fs_info->pinned_extents,
fs_info->btree_inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&fs_info->pending_del,
fs_info->btree_inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&fs_info->extent_ins,
fs_info->btree_inode->i_mapping, GFP_NOFS);
fs_info->do_barriers = 1;
fs_info->closing = 0;
fs_info->total_pinned = 0;
fs_info->last_alloc = 0;
fs_info->last_data_alloc = 0;
fs_info->extra_alloc_bits = 0;
fs_info->extra_data_alloc_bits = 0;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
#else
INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
#endif
BTRFS_I(fs_info->btree_inode)->root = tree_root;
memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
sizeof(struct btrfs_key));
insert_inode_hash(fs_info->btree_inode);
mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
mutex_init(&fs_info->trans_mutex);
mutex_init(&fs_info->fs_mutex);
#if 0
ret = add_hasher(fs_info, "crc32c");
if (ret) {
printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
err = -ENOMEM;
goto fail_iput;
}
#endif
__setup_root(4096, 4096, 4096, 4096, tree_root,
fs_info, BTRFS_ROOT_TREE_OBJECTID);
fs_info->sb_buffer = read_tree_block(tree_root,
BTRFS_SUPER_INFO_OFFSET,
4096);
if (!fs_info->sb_buffer)
goto fail_iput;
read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
sizeof(fs_info->super_copy));
read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
(unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
BTRFS_FSID_SIZE);
disk_super = &fs_info->super_copy;
if (!btrfs_super_root(disk_super))
goto fail_sb_buffer;
if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
printk("Btrfs: wanted %llu devices, but found %llu\n",
(unsigned long long)btrfs_super_num_devices(disk_super),
(unsigned long long)fs_devices->num_devices);
goto fail_sb_buffer;
}
nodesize = btrfs_super_nodesize(disk_super);
leafsize = btrfs_super_leafsize(disk_super);
sectorsize = btrfs_super_sectorsize(disk_super);
stripesize = btrfs_super_stripesize(disk_super);
tree_root->nodesize = nodesize;
tree_root->leafsize = leafsize;
tree_root->sectorsize = sectorsize;
tree_root->stripesize = stripesize;
sb_set_blocksize(sb, sectorsize);
i_size_write(fs_info->btree_inode,
btrfs_super_total_bytes(disk_super));
if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->magic))) {
printk("btrfs: valid FS not found on %s\n", sb->s_id);
goto fail_sb_buffer;
}
mutex_lock(&fs_info->fs_mutex);
ret = btrfs_read_sys_array(tree_root);
BUG_ON(ret);
blocksize = btrfs_level_size(tree_root,
btrfs_super_chunk_root_level(disk_super));
__setup_root(nodesize, leafsize, sectorsize, stripesize,
chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
chunk_root->node = read_tree_block(chunk_root,
btrfs_super_chunk_root(disk_super),
blocksize);
BUG_ON(!chunk_root->node);
ret = btrfs_read_chunk_tree(chunk_root);
BUG_ON(ret);
blocksize = btrfs_level_size(tree_root,
btrfs_super_root_level(disk_super));
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super),
blocksize);
if (!tree_root->node)
goto fail_sb_buffer;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_EXTENT_TREE_OBJECTID, extent_root);
if (ret)
goto fail_tree_root;
extent_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_DEV_TREE_OBJECTID, dev_root);
dev_root->track_dirty = 1;
if (ret)
goto fail_extent_root;
btrfs_read_block_groups(extent_root);
fs_info->generation = btrfs_super_generation(disk_super) + 1;
mutex_unlock(&fs_info->fs_mutex);
return tree_root;
fail_extent_root:
free_extent_buffer(extent_root->node);
fail_tree_root:
mutex_unlock(&fs_info->fs_mutex);
free_extent_buffer(tree_root->node);
fail_sb_buffer:
free_extent_buffer(fs_info->sb_buffer);
fail_iput:
iput(fs_info->btree_inode);
fail:
close_all_devices(fs_info);
kfree(extent_root);
kfree(tree_root);
kfree(fs_info);
return ERR_PTR(err);
}
int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
*root)
{
int ret;
struct extent_buffer *super = root->fs_info->sb_buffer;
struct inode *btree_inode = root->fs_info->btree_inode;
struct super_block *sb = root->fs_info->sb;
if (!btrfs_test_opt(root, NOBARRIER))
blkdev_issue_flush(sb->s_bdev, NULL);
set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
super->start, super->len);
if (!btrfs_test_opt(root, NOBARRIER))
blkdev_issue_flush(sb->s_bdev, NULL);
return ret;
}
int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
{
radix_tree_delete(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid);
if (root->in_sysfs)
btrfs_sysfs_del_root(root);
if (root->inode)
iput(root->inode);
if (root->node)
free_extent_buffer(root->node);
if (root->commit_root)
free_extent_buffer(root->commit_root);
if (root->name)
kfree(root->name);
kfree(root);
return 0;
}
static int del_fs_roots(struct btrfs_fs_info *fs_info)
{
int ret;
struct btrfs_root *gang[8];
int i;
while(1) {
ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
(void **)gang, 0,
ARRAY_SIZE(gang));
if (!ret)
break;
for (i = 0; i < ret; i++)
btrfs_free_fs_root(fs_info, 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;
fs_info->closing = 1;
btrfs_transaction_flush_work(root);
mutex_lock(&fs_info->fs_mutex);
btrfs_defrag_dirty_roots(root->fs_info);
trans = btrfs_start_transaction(root, 1);
ret = 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->delalloc_bytes) {
printk("btrfs: at unmount delalloc count %Lu\n",
fs_info->delalloc_bytes);
}
if (fs_info->extent_root->node)
free_extent_buffer(fs_info->extent_root->node);
if (fs_info->tree_root->node)
free_extent_buffer(fs_info->tree_root->node);
if (root->fs_info->chunk_root->node);
free_extent_buffer(root->fs_info->chunk_root->node);
if (root->fs_info->dev_root->node);
free_extent_buffer(root->fs_info->dev_root->node);
free_extent_buffer(fs_info->sb_buffer);
btrfs_free_block_groups(root->fs_info);
del_fs_roots(fs_info);
filemap_write_and_wait(fs_info->btree_inode->i_mapping);
extent_io_tree_empty_lru(&fs_info->free_space_cache);
extent_io_tree_empty_lru(&fs_info->block_group_cache);
extent_io_tree_empty_lru(&fs_info->pinned_extents);
extent_io_tree_empty_lru(&fs_info->pending_del);
extent_io_tree_empty_lru(&fs_info->extent_ins);
extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
iput(fs_info->btree_inode);
#if 0
while(!list_empty(&fs_info->hashers)) {
struct btrfs_hasher *hasher;
hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
hashers);
list_del(&hasher->hashers);
crypto_free_hash(&fs_info->hash_tfm);
kfree(hasher);
}
#endif
close_all_devices(fs_info);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
kfree(fs_info->extent_root);
kfree(fs_info->tree_root);
kfree(fs_info->chunk_root);
kfree(fs_info->dev_root);
return 0;
}
int btrfs_buffer_uptodate(struct extent_buffer *buf)
{
struct inode *btree_inode = buf->first_page->mapping->host;
return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
}
int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
{
struct inode *btree_inode = buf->first_page->mapping->host;
return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
buf);
}
void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
u64 transid = btrfs_header_generation(buf);
struct inode *btree_inode = root->fs_info->btree_inode;
if (transid != root->fs_info->generation) {
printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
(unsigned long long)buf->start,
transid, root->fs_info->generation);
WARN_ON(1);
}
set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
}
void btrfs_throttle(struct btrfs_root *root)
{
struct backing_dev_info *bdi;
bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
if (root->fs_info->throttles && bdi_write_congested(bdi)) {
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
congestion_wait(WRITE, HZ/20);
#else
blk_congestion_wait(WRITE, HZ/20);
#endif
}
}
void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
{
balance_dirty_pages_ratelimited_nr(
root->fs_info->btree_inode->i_mapping, 1);
}
void btrfs_set_buffer_defrag(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
}
void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
GFP_NOFS);
}
int btrfs_buffer_defrag(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
}
int btrfs_buffer_defrag_done(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG_DONE, 0);
}
int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG_DONE, GFP_NOFS);
}
int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG, GFP_NOFS);
}
int btrfs_read_buffer(struct extent_buffer *buf)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, 1, btree_get_extent);
}
static struct extent_io_ops btree_extent_io_ops = {
.writepage_io_hook = btree_writepage_io_hook,
.submit_bio_hook = btree_submit_bio_hook,
/* note we're sharing with inode.c for the merge bio hook */
.merge_bio_hook = btrfs_merge_bio_hook,
};