Select Git revision
disk-io.c 68.22 KiB
/*
* 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/scatterlist.h>
#include <linux/swap.h>
#include <linux/radix-tree.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/crc32c.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "volumes.h"
#include "print-tree.h"
#include "async-thread.h"
#include "locking.h"
#include "tree-log.h"
#include "free-space-cache.h"
static struct extent_io_ops btree_extent_io_ops;
static void end_workqueue_fn(struct btrfs_work *work);
static void free_fs_root(struct btrfs_root *root);
static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
/*
* end_io_wq structs are used to do processing in task context when an IO is
* complete. This is used during reads to verify checksums, and it is used
* by writes to insert metadata for new file extents after IO is complete.
*/
struct end_io_wq {
struct bio *bio;
bio_end_io_t *end_io;
void *private;
struct btrfs_fs_info *info;
int error;
int metadata;
struct list_head list;
struct btrfs_work work;
};
/*
* async submit bios are used to offload expensive checksumming
* onto the worker threads. They checksum file and metadata bios
* just before they are sent down the IO stack.
*/
struct async_submit_bio {
struct inode *inode; struct bio *bio;
struct list_head list;
extent_submit_bio_hook_t *submit_bio_start;
extent_submit_bio_hook_t *submit_bio_done;
int rw;
int mirror_num;
unsigned long bio_flags;
struct btrfs_work work;
};
/* These are used to set the lockdep class on the extent buffer locks.
* The class is set by the readpage_end_io_hook after the buffer has
* passed csum validation but before the pages are unlocked.
*
* The lockdep class is also set by btrfs_init_new_buffer on freshly
* allocated blocks.
*
* The class is based on the level in the tree block, which allows lockdep
* to know that lower nodes nest inside the locks of higher nodes.
*
* We also add a check to make sure the highest level of the tree is
* the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
* code needs update as well.
*/
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# if BTRFS_MAX_LEVEL != 8
# error
# endif
static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
/* leaf */
"btrfs-extent-00",
"btrfs-extent-01",
"btrfs-extent-02",
"btrfs-extent-03",
"btrfs-extent-04",
"btrfs-extent-05",
"btrfs-extent-06",
"btrfs-extent-07",
/* highest possible level */
"btrfs-extent-08",
};
#endif
/*
* extents on the btree inode are pretty simple, there's one extent
* that covers the entire device
*/
static 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;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em) {
em->bdev =
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
read_unlock(&em_tree->lock);
goto out;
}
read_unlock(&em_tree->lock);
em = alloc_extent_map(GFP_NOFS);
if (!em) {
em = ERR_PTR(-ENOMEM);
goto out; }
em->start = 0;
em->len = (u64)-1;
em->block_len = (u64)-1;
em->block_start = 0;
em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
if (ret == -EEXIST) {
u64 failed_start = em->start;
u64 failed_len = em->len;
free_extent_map(em);
em = lookup_extent_mapping(em_tree, start, len);
if (em) {
ret = 0;
} else {
em = lookup_extent_mapping(em_tree, failed_start,
failed_len);
ret = -EIO;
}
} else if (ret) {
free_extent_map(em);
em = NULL;
}
write_unlock(&em_tree->lock);
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);
}
/*
* compute the csum for a btree block, and either verify it or write it
* into the csum field of the block.
*/
static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify)
{
u16 csum_size =
btrfs_super_csum_size(&root->fs_info->super_copy);
char *result = NULL;
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;
unsigned long inline_result;
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)
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);
}
if (csum_size > sizeof(inline_result)) {
result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
if (!result)
return 1;
} else {
result = (char *)&inline_result;
}
btrfs_csum_final(crc, result);
if (verify) {
if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
u32 val;
u32 found = 0;
memcpy(&found, result, csum_size);
read_extent_buffer(buf, &val, 0, csum_size);
if (printk_ratelimit()) {
printk(KERN_INFO "btrfs: %s checksum verify "
"failed on %llu wanted %X found %X "
"level %d\n",
root->fs_info->sb->s_id,
(unsigned long long)buf->start, val, found,
btrfs_header_level(buf));
}
if (result != (char *)&inline_result)
kfree(result);
return 1;
}
} else {
write_extent_buffer(buf, result, 0, csum_size);
}
if (result != (char *)&inline_result)
kfree(result);
return 0;
}
/*
* we can't consider a given block up to date unless the transid of the
* block matches the transid in the parent node's pointer. This is how we
* detect blocks that either didn't get written at all or got written
* in the wrong place.
*/
static int verify_parent_transid(struct extent_io_tree *io_tree,
struct extent_buffer *eb, u64 parent_transid)
{
int ret;
if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
return 0;
lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
if (extent_buffer_uptodate(io_tree, eb) &&
btrfs_header_generation(eb) == parent_transid) {
ret = 0;
goto out;
}
if (printk_ratelimit()) {
printk("parent transid verify failed on %llu wanted %llu "
"found %llu\n",
(unsigned long long)eb->start, (unsigned long long)parent_transid,
(unsigned long long)btrfs_header_generation(eb));
}
ret = 1;
clear_extent_buffer_uptodate(io_tree, eb);
out:
unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
GFP_NOFS);
return ret;
}
/*
* helper to read a given tree block, doing retries as required when
* the checksums don't match and we have alternate mirrors to try.
*/
static int btree_read_extent_buffer_pages(struct btrfs_root *root,
struct extent_buffer *eb,
u64 start, u64 parent_transid)
{
struct extent_io_tree *io_tree;
int ret;
int num_copies = 0;
int mirror_num = 0;
io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
while (1) {
ret = read_extent_buffer_pages(io_tree, eb, start, 1,
btree_get_extent, mirror_num);
if (!ret &&
!verify_parent_transid(io_tree, eb, parent_transid))
return ret;
num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
eb->start, eb->len);
if (num_copies == 1)
return ret;
mirror_num++;
if (mirror_num > num_copies)
return ret;
}
return -EIO;
}
/*
* checksum a dirty tree block before IO. This has extra checks to make sure
* we only fill in the checksum field in the first page of a multi-page block
*/
static 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;
int ret;
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;
WARN_ON(len == 0);
eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE, btrfs_header_generation(eb));
BUG_ON(ret);
found_start = btrfs_header_bytenr(eb);
if (found_start != start) {
WARN_ON(1);
goto err;
}
if (eb->first_page != page) {
WARN_ON(1);
goto err;
}
if (!PageUptodate(page)) {
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 check_tree_block_fsid(struct btrfs_root *root,
struct extent_buffer *eb)
{
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
u8 fsid[BTRFS_UUID_SIZE];
int ret = 1;
read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
BTRFS_FSID_SIZE);
while (fs_devices) {
if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
ret = 0;
break;
}
fs_devices = fs_devices->seed;
}
return ret;
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
{
lockdep_set_class_and_name(&eb->lock,
&btrfs_eb_class[level],
btrfs_eb_name[level]);
}
#endif
static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state)
{
struct extent_io_tree *tree;
u64 found_start;
int found_level;
unsigned long len;
struct extent_buffer *eb;
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
int ret = 0;
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; WARN_ON(len == 0);
eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
found_start = btrfs_header_bytenr(eb);
if (found_start != start) {
if (printk_ratelimit()) {
printk(KERN_INFO "btrfs bad tree block start "
"%llu %llu\n",
(unsigned long long)found_start,
(unsigned long long)eb->start);
}
ret = -EIO;
goto err;
}
if (eb->first_page != page) {
printk(KERN_INFO "btrfs bad first page %lu %lu\n",
eb->first_page->index, page->index);
WARN_ON(1);
ret = -EIO;
goto err;
}
if (check_tree_block_fsid(root, eb)) {
if (printk_ratelimit()) {
printk(KERN_INFO "btrfs bad fsid on block %llu\n",
(unsigned long long)eb->start);
}
ret = -EIO;
goto err;
}
found_level = btrfs_header_level(eb);
btrfs_set_buffer_lockdep_class(eb, found_level);
ret = csum_tree_block(root, eb, 1);
if (ret)
ret = -EIO;
end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
end = eb->start + end - 1;
err:
free_extent_buffer(eb);
out:
return ret;
}
static void end_workqueue_bio(struct bio *bio, int err)
{
struct end_io_wq *end_io_wq = bio->bi_private;
struct btrfs_fs_info *fs_info;
fs_info = end_io_wq->info;
end_io_wq->error = err;
end_io_wq->work.func = end_workqueue_fn;
end_io_wq->work.flags = 0;
if (bio->bi_rw & (1 << BIO_RW)) {
if (end_io_wq->metadata)
btrfs_queue_worker(&fs_info->endio_meta_write_workers,
&end_io_wq->work);
else
btrfs_queue_worker(&fs_info->endio_write_workers,
&end_io_wq->work);
} else {
if (end_io_wq->metadata)
btrfs_queue_worker(&fs_info->endio_meta_workers,
&end_io_wq->work);
else
btrfs_queue_worker(&fs_info->endio_workers,
&end_io_wq->work); }
}
int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
int metadata)
{
struct end_io_wq *end_io_wq;
end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
if (!end_io_wq)
return -ENOMEM;
end_io_wq->private = bio->bi_private;
end_io_wq->end_io = bio->bi_end_io;
end_io_wq->info = info;
end_io_wq->error = 0;
end_io_wq->bio = bio;
end_io_wq->metadata = metadata;
bio->bi_private = end_io_wq;
bio->bi_end_io = end_workqueue_bio;
return 0;
}
unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
{
unsigned long limit = min_t(unsigned long,
info->workers.max_workers,
info->fs_devices->open_devices);
return 256 * limit;
}
int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
{
return atomic_read(&info->nr_async_bios) >
btrfs_async_submit_limit(info);
}
static void run_one_async_start(struct btrfs_work *work)
{
struct btrfs_fs_info *fs_info;
struct async_submit_bio *async;
async = container_of(work, struct async_submit_bio, work);
fs_info = BTRFS_I(async->inode)->root->fs_info;
async->submit_bio_start(async->inode, async->rw, async->bio,
async->mirror_num, async->bio_flags);
}
static void run_one_async_done(struct btrfs_work *work)
{
struct btrfs_fs_info *fs_info;
struct async_submit_bio *async;
int limit;
async = container_of(work, struct async_submit_bio, work);
fs_info = BTRFS_I(async->inode)->root->fs_info;
limit = btrfs_async_submit_limit(fs_info);
limit = limit * 2 / 3;
atomic_dec(&fs_info->nr_async_submits);
if (atomic_read(&fs_info->nr_async_submits) < limit &&
waitqueue_active(&fs_info->async_submit_wait))
wake_up(&fs_info->async_submit_wait);
async->submit_bio_done(async->inode, async->rw, async->bio,
async->mirror_num, async->bio_flags);
}
static void run_one_async_free(struct btrfs_work *work)
{
struct async_submit_bio *async;
async = container_of(work, struct async_submit_bio, work);
kfree(async);
}
int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
int rw, struct bio *bio, int mirror_num,
unsigned long bio_flags,
extent_submit_bio_hook_t *submit_bio_start,
extent_submit_bio_hook_t *submit_bio_done)
{
struct async_submit_bio *async;
async = kmalloc(sizeof(*async), GFP_NOFS);
if (!async)
return -ENOMEM;
async->inode = inode;
async->rw = rw;
async->bio = bio;
async->mirror_num = mirror_num;
async->submit_bio_start = submit_bio_start;
async->submit_bio_done = submit_bio_done;
async->work.func = run_one_async_start;
async->work.ordered_func = run_one_async_done;
async->work.ordered_free = run_one_async_free;
async->work.flags = 0;
async->bio_flags = bio_flags;
atomic_inc(&fs_info->nr_async_submits);
if (rw & (1 << BIO_RW_SYNCIO))
btrfs_set_work_high_prio(&async->work);
btrfs_queue_worker(&fs_info->workers, &async->work);
while (atomic_read(&fs_info->async_submit_draining) &&
atomic_read(&fs_info->nr_async_submits)) {
wait_event(fs_info->async_submit_wait,
(atomic_read(&fs_info->nr_async_submits) == 0));
}
return 0;
}
static int btree_csum_one_bio(struct bio *bio)
{
struct bio_vec *bvec = bio->bi_io_vec;
int bio_index = 0;
struct btrfs_root *root;
WARN_ON(bio->bi_vcnt <= 0);
while (bio_index < bio->bi_vcnt) {
root = BTRFS_I(bvec->bv_page->mapping->host)->root;
csum_dirty_buffer(root, bvec->bv_page);
bio_index++;
bvec++;
}
return 0;
}
static int __btree_submit_bio_start(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags)
{ /*
* when we're called for a write, we're already in the async
* submission context. Just jump into btrfs_map_bio
*/
btree_csum_one_bio(bio);
return 0;
}
static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags)
{
/*
* when we're called for a write, we're already in the async
* submission context. Just jump into btrfs_map_bio
*/
return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
}
static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags)
{
int ret;
ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
bio, 1);
BUG_ON(ret);
if (!(rw & (1 << BIO_RW))) {
/*
* called for a read, do the setup so that checksum validation
* can happen in the async kernel threads
*/
return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
mirror_num, 0);
}
/*
* kthread helpers are used to submit writes so that checksumming
* can happen in parallel across all CPUs
*/
return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
inode, rw, bio, mirror_num, 0,
__btree_submit_bio_start,
__btree_submit_bio_done);
}
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_io_tree *tree;
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
struct extent_buffer *eb;
int was_dirty;
tree = &BTRFS_I(page->mapping->host)->io_tree;
if (!(current->flags & PF_MEMALLOC)) {
return extent_write_full_page(tree, page,
btree_get_extent, wbc);
}
redirty_page_for_writepage(wbc, page);
eb = btrfs_find_tree_block(root, page_offset(page),
PAGE_CACHE_SIZE);
WARN_ON(!eb);
was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
if (!was_dirty) {
spin_lock(&root->fs_info->delalloc_lock);
root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
spin_unlock(&root->fs_info->delalloc_lock);
} free_extent_buffer(eb);
unlock_page(page);
return 0;
}
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) {
struct btrfs_root *root = BTRFS_I(mapping->host)->root;
u64 num_dirty;
unsigned long thresh = 32 * 1024 * 1024;
if (wbc->for_kupdate)
return 0;
/* this is a bit racy, but that's ok */
num_dirty = root->fs_info->dirty_metadata_bytes;
if (num_dirty < thresh)
return 0;
}
return extent_writepages(tree, mapping, btree_get_extent, wbc);
}
static 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;
if (PageWriteback(page) || PageDirty(page))
return 0;
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_state(map, tree, page, gfp_flags);
if (!ret)
return 0;
ret = try_release_extent_buffer(tree, page);
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 (PagePrivate(page)) {
printk(KERN_WARNING "btrfs warning page private not zero "
"on page %llu\n", (unsigned long long)page_offset(page));
ClearPagePrivate(page); set_page_private(page, 0);
page_cache_release(page);
}
}
static const 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,
u64 parent_transid)
{
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, 0);
free_extent_buffer(buf);
return ret;
}
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;
}
int btrfs_write_tree_block(struct extent_buffer *buf)
{
return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
buf->start + buf->len - 1);
}
int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
return filemap_fdatawait_range(buf->first_page->mapping,
buf->start, buf->start + buf->len - 1);
}
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid)
{
struct extent_buffer *buf = NULL;
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_io_tree *io_tree; int ret;
io_tree = &BTRFS_I(btree_inode)->io_tree;
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return NULL;
ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
if (ret == 0)
set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
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) {
btrfs_assert_tree_locked(buf);
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
spin_lock(&root->fs_info->delalloc_lock);
if (root->fs_info->dirty_metadata_bytes >= buf->len)
root->fs_info->dirty_metadata_bytes -= buf->len;
else
WARN_ON(1);
spin_unlock(&root->fs_info->delalloc_lock);
}
/* ugh, clear_extent_buffer_dirty needs to lock the page */
btrfs_set_lock_blocking(buf);
clear_extent_buffer_dirty(&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->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_objectid = 0;
root->name = NULL;
root->in_sysfs = 0;
root->inode_tree.rb_node = NULL;
INIT_LIST_HEAD(&root->dirty_list);
INIT_LIST_HEAD(&root->orphan_list);
INIT_LIST_HEAD(&root->root_list);
spin_lock_init(&root->node_lock);
spin_lock_init(&root->list_lock);
spin_lock_init(&root->inode_lock);
mutex_init(&root->objectid_mutex); mutex_init(&root->log_mutex);
init_waitqueue_head(&root->log_writer_wait);
init_waitqueue_head(&root->log_commit_wait[0]);
init_waitqueue_head(&root->log_commit_wait[1]);
atomic_set(&root->log_commit[0], 0);
atomic_set(&root->log_commit[1], 0);
atomic_set(&root->log_writers, 0);
root->log_batch = 0;
root->log_transid = 0;
extent_io_tree_init(&root->dirty_log_pages,
fs_info->btree_inode->i_mapping, GFP_NOFS);
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));
root->defrag_trans_start = fs_info->generation;
init_completion(&root->kobj_unregister);
root->defrag_running = 0;
root->defrag_level = 0;
root->root_key.objectid = objectid;
root->anon_super.s_root = NULL;
root->anon_super.s_dev = 0;
INIT_LIST_HEAD(&root->anon_super.s_list);
INIT_LIST_HEAD(&root->anon_super.s_instances);
init_rwsem(&root->anon_super.s_umount);
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;
u64 generation;
__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);
if (ret > 0)
return -ENOENT;
BUG_ON(ret);
generation = btrfs_root_generation(&root->root_item);
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
BUG_ON(!root->node);
root->commit_root = btrfs_root_node(root);
return 0;
}
int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
struct extent_buffer *eb;
struct btrfs_root *log_root_tree = fs_info->log_root_tree;
u64 start = 0;
u64 end = 0;
int ret;
if (!log_root_tree)
return 0;
while (1) { ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
0, &start, &end, EXTENT_DIRTY);
if (ret)
break;
clear_extent_dirty(&log_root_tree->dirty_log_pages,
start, end, GFP_NOFS);
}
eb = fs_info->log_root_tree->node;
WARN_ON(btrfs_header_level(eb) != 0);
WARN_ON(btrfs_header_nritems(eb) != 0);
ret = btrfs_free_reserved_extent(fs_info->tree_root,
eb->start, eb->len);
BUG_ON(ret);
free_extent_buffer(eb);
kfree(fs_info->log_root_tree);
fs_info->log_root_tree = NULL;
return 0;
}
static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root;
struct btrfs_root *tree_root = fs_info->tree_root;
struct extent_buffer *leaf;
root = kzalloc(sizeof(*root), GFP_NOFS);
if (!root)
return ERR_PTR(-ENOMEM);
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
root, fs_info, BTRFS_TREE_LOG_OBJECTID);
root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
root->root_key.type = BTRFS_ROOT_ITEM_KEY;
root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
/*
* log trees do not get reference counted because they go away
* before a real commit is actually done. They do store pointers
* to file data extents, and those reference counts still get
* updated (along with back refs to the log tree).
*/
root->ref_cows = 0;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
if (IS_ERR(leaf)) {
kfree(root);
return ERR_CAST(leaf);
}
memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
root->node = leaf;
write_extent_buffer(root->node, root->fs_info->fsid,
(unsigned long)btrfs_header_fsid(root->node),
BTRFS_FSID_SIZE);
btrfs_mark_buffer_dirty(root->node);
btrfs_tree_unlock(root->node);
return root;
}
int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
struct btrfs_root *log_root;
log_root = alloc_log_tree(trans, fs_info);
if (IS_ERR(log_root))
return PTR_ERR(log_root);
WARN_ON(fs_info->log_root_tree);
fs_info->log_root_tree = log_root;
return 0;
}
int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_root *log_root;
struct btrfs_inode_item *inode_item;
log_root = alloc_log_tree(trans, root->fs_info);
if (IS_ERR(log_root))
return PTR_ERR(log_root);
log_root->last_trans = trans->transid;
log_root->root_key.offset = root->root_key.objectid;
inode_item = &log_root->root_item.inode;
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
inode_item->nbytes = cpu_to_le64(root->leafsize);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_node(&log_root->root_item, log_root->node);
WARN_ON(root->log_root);
root->log_root = log_root;
root->log_transid = 0;
return 0;
}
struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
struct btrfs_key *location)
{
struct btrfs_root *root;
struct btrfs_fs_info *fs_info = tree_root->fs_info;
struct btrfs_path *path;
struct extent_buffer *l;
u64 generation;
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 out;
}
__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) {
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));
}
btrfs_free_path(path);
if (ret) {
if (ret > 0)
ret = -ENOENT;
return ERR_PTR(ret);
}
generation = btrfs_root_generation(&root->root_item);
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
root->commit_root = btrfs_root_node(root);
BUG_ON(!root->node);
out:
if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
root->ref_cows = 1;
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;
if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
return fs_info->chunk_root;
if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
return fs_info->dev_root;
if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
return fs_info->csum_root;
again:
spin_lock(&fs_info->fs_roots_radix_lock);
root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)location->objectid);
spin_unlock(&fs_info->fs_roots_radix_lock);
if (root)
return root;
ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid); if (ret == 0)
ret = -ENOENT;
if (ret < 0)
return ERR_PTR(ret);
root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
if (IS_ERR(root))
return root;
WARN_ON(btrfs_root_refs(&root->root_item) == 0);
set_anon_super(&root->anon_super, NULL);
ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
if (ret)
goto fail;
spin_lock(&fs_info->fs_roots_radix_lock);
ret = radix_tree_insert(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
root);
if (ret == 0)
root->in_radix = 1;
spin_unlock(&fs_info->fs_roots_radix_lock);
radix_tree_preload_end();
if (ret) {
if (ret == -EEXIST) {
free_fs_root(root);
goto again;
}
goto fail;
}
ret = btrfs_find_dead_roots(fs_info->tree_root,
root->root_key.objectid);
WARN_ON(ret);
if (!(fs_info->sb->s_flags & MS_RDONLY))
btrfs_orphan_cleanup(root);
return root;
fail:
free_fs_root(root);
return ERR_PTR(ret);
}
struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
struct btrfs_key *location,
const char *name, int namelen)
{
return btrfs_read_fs_root_no_name(fs_info, location);
#if 0
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;
#endif
}
static int btrfs_congested_fn(void *congested_data, int bdi_bits)
{
struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
int ret = 0;
struct btrfs_device *device;
struct backing_dev_info *bdi;
list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
if (!device->bdev)
continue;
bdi = blk_get_backing_dev_info(device->bdev);
if (bdi && bdi_congested(bdi, bdi_bits)) {
ret = 1;
break;
}
}
return ret;
}
/*
* this unplugs every device on the box, and it is only used when page
* is null
*/
static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
{
struct btrfs_device *device;
struct btrfs_fs_info *info;
info = (struct btrfs_fs_info *)bdi->unplug_io_data;
list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
if (!device->bdev)
continue;
bdi = blk_get_backing_dev_info(device->bdev);
if (bdi->unplug_io_fn)
bdi->unplug_io_fn(bdi, page);
}
}
static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
{
struct inode *inode;
struct extent_map_tree *em_tree;
struct extent_map *em;
struct address_space *mapping;
u64 offset;
/* the generic O_DIRECT read code does this */
if (1 || !page) {
__unplug_io_fn(bdi, page);
return;
}
/*
* page->mapping may change at any time. Get a consistent copy
* and use that for everything below
*/
smp_mb();
mapping = page->mapping;
if (!mapping) return;
inode = mapping->host;
/*
* don't do the expensive searching for a small number of
* devices
*/
if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
__unplug_io_fn(bdi, page);
return;
}
offset = page_offset(page);
em_tree = &BTRFS_I(inode)->extent_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
read_unlock(&em_tree->lock);
if (!em) {
__unplug_io_fn(bdi, page);
return;
}
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
__unplug_io_fn(bdi, page);
return;
}
offset = offset - em->start;
btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
em->block_start + offset, page);
free_extent_map(em);
}
/*
* If this fails, caller must call bdi_destroy() to get rid of the
* bdi again.
*/
static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
{
int err;
bdi->name = "btrfs";
bdi->capabilities = BDI_CAP_MAP_COPY;
err = bdi_init(bdi);
if (err)
return err;
err = bdi_register(bdi, NULL, "btrfs-%d",
atomic_inc_return(&btrfs_bdi_num));
if (err) {
bdi_destroy(bdi);
return err;
}
bdi->ra_pages = default_backing_dev_info.ra_pages;
bdi->unplug_io_fn = btrfs_unplug_io_fn;
bdi->unplug_io_data = info;
bdi->congested_fn = btrfs_congested_fn;
bdi->congested_data = info;
return 0;
}
static int bio_ready_for_csum(struct bio *bio)
{
u64 length = 0;
u64 buf_len = 0;
u64 start = 0;
struct page *page; struct extent_io_tree *io_tree = NULL;
struct btrfs_fs_info *info = NULL;
struct bio_vec *bvec;
int i;
int ret;
bio_for_each_segment(bvec, bio, i) {
page = bvec->bv_page;
if (page->private == EXTENT_PAGE_PRIVATE) {
length += bvec->bv_len;
continue;
}
if (!page->private) {
length += bvec->bv_len;
continue;
}
length = bvec->bv_len;
buf_len = page->private >> 2;
start = page_offset(page) + bvec->bv_offset;
io_tree = &BTRFS_I(page->mapping->host)->io_tree;
info = BTRFS_I(page->mapping->host)->root->fs_info;
}
/* are we fully contained in this bio? */
if (buf_len <= length)
return 1;
ret = extent_range_uptodate(io_tree, start + length,
start + buf_len - 1);
return ret;
}
/*
* called by the kthread helper functions to finally call the bio end_io
* functions. This is where read checksum verification actually happens
*/
static void end_workqueue_fn(struct btrfs_work *work)
{
struct bio *bio;
struct end_io_wq *end_io_wq;
struct btrfs_fs_info *fs_info;
int error;
end_io_wq = container_of(work, struct end_io_wq, work);
bio = end_io_wq->bio;
fs_info = end_io_wq->info;
/* metadata bio reads are special because the whole tree block must
* be checksummed at once. This makes sure the entire block is in
* ram and up to date before trying to verify things. For
* blocksize <= pagesize, it is basically a noop
*/
if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
!bio_ready_for_csum(bio)) {
btrfs_queue_worker(&fs_info->endio_meta_workers,
&end_io_wq->work);
return;
}
error = end_io_wq->error;
bio->bi_private = end_io_wq->private;
bio->bi_end_io = end_io_wq->end_io;
kfree(end_io_wq);
bio_endio(bio, error);
}
static int cleaner_kthread(void *arg)
{
struct btrfs_root *root = arg;
do {
smp_mb(); if (root->fs_info->closing)
break;
vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
mutex_trylock(&root->fs_info->cleaner_mutex)) {
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
}
if (freezing(current)) {
refrigerator();
} else {
smp_mb();
if (root->fs_info->closing)
break;
set_current_state(TASK_INTERRUPTIBLE);
schedule();
__set_current_state(TASK_RUNNING);
}
} while (!kthread_should_stop());
return 0;
}
static int transaction_kthread(void *arg)
{
struct btrfs_root *root = arg;
struct btrfs_trans_handle *trans;
struct btrfs_transaction *cur;
unsigned long now;
unsigned long delay;
int ret;
do {
smp_mb();
if (root->fs_info->closing)
break;
delay = HZ * 30;
vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
mutex_lock(&root->fs_info->transaction_kthread_mutex);
mutex_lock(&root->fs_info->trans_mutex);
cur = root->fs_info->running_transaction;
if (!cur) {
mutex_unlock(&root->fs_info->trans_mutex);
goto sleep;
}
now = get_seconds();
if (now < cur->start_time || now - cur->start_time < 30) {
mutex_unlock(&root->fs_info->trans_mutex);
delay = HZ * 5;
goto sleep;
}
mutex_unlock(&root->fs_info->trans_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sleep:
wake_up_process(root->fs_info->cleaner_kthread);
mutex_unlock(&root->fs_info->transaction_kthread_mutex);
if (freezing(current)) {
refrigerator();
} else {
if (root->fs_info->closing)
break;
set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(delay);
__set_current_state(TASK_RUNNING);
}
} while (!kthread_should_stop());
return 0;
}
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices,
char *options)
{
u32 sectorsize;
u32 nodesize;
u32 leafsize;
u32 blocksize;
u32 stripesize;
u64 generation;
u64 features;
struct btrfs_key location;
struct buffer_head *bh;
struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
GFP_NOFS);
struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *log_tree_root;
int ret;
int err = -EINVAL;
struct btrfs_super_block *disk_super;
if (!extent_root || !tree_root || !fs_info ||
!chunk_root || !dev_root || !csum_root) {
err = -ENOMEM;
goto fail;
}
ret = init_srcu_struct(&fs_info->subvol_srcu);
if (ret) {
err = ret;
goto fail;
}
ret = setup_bdi(fs_info, &fs_info->bdi);
if (ret) {
err = ret;
goto fail_srcu;
}
fs_info->btree_inode = new_inode(sb);
if (!fs_info->btree_inode) {
err = -ENOMEM;
goto fail_bdi;
}
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
INIT_LIST_HEAD(&fs_info->trans_list);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->hashers);
INIT_LIST_HEAD(&fs_info->delalloc_inodes);
INIT_LIST_HEAD(&fs_info->ordered_operations);
INIT_LIST_HEAD(&fs_info->caching_block_groups); spin_lock_init(&fs_info->delalloc_lock);
spin_lock_init(&fs_info->new_trans_lock);
spin_lock_init(&fs_info->ref_cache_lock);
spin_lock_init(&fs_info->fs_roots_radix_lock);
init_completion(&fs_info->kobj_unregister);
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
fs_info->csum_root = csum_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);
atomic_set(&fs_info->nr_async_submits, 0);
atomic_set(&fs_info->async_delalloc_pages, 0);
atomic_set(&fs_info->async_submit_draining, 0);
atomic_set(&fs_info->nr_async_bios, 0);
fs_info->sb = sb;
fs_info->max_extent = (u64)-1;
fs_info->max_inline = 8192 * 1024;
fs_info->metadata_ratio = 0;
fs_info->thread_pool_size = min_t(unsigned long,
num_online_cpus() + 2, 8);
INIT_LIST_HEAD(&fs_info->ordered_extents);
spin_lock_init(&fs_info->ordered_extent_lock);
sb->s_blocksize = 4096;
sb->s_blocksize_bits = blksize_bits(4096);
sb->s_bdi = &fs_info->bdi;
fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
fs_info->btree_inode->i_nlink = 1;
/*
* we set the i_size on the btree inode to the max possible int.
* the real end of the address space is determined by all of
* the devices in the system
*/
fs_info->btree_inode->i_size = OFFSET_MAX;
fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
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;
BTRFS_I(fs_info->btree_inode)->root = tree_root;
memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
sizeof(struct btrfs_key));
BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
insert_inode_hash(fs_info->btree_inode);
spin_lock_init(&fs_info->block_group_cache_lock);
fs_info->block_group_cache_tree.rb_node = NULL;
extent_io_tree_init(&fs_info->freed_extents[0],
fs_info->btree_inode->i_mapping, GFP_NOFS);
extent_io_tree_init(&fs_info->freed_extents[1],
fs_info->btree_inode->i_mapping, GFP_NOFS);
fs_info->pinned_extents = &fs_info->freed_extents[0];
fs_info->do_barriers = 1;
mutex_init(&fs_info->trans_mutex);
mutex_init(&fs_info->ordered_operations_mutex);
mutex_init(&fs_info->tree_log_mutex);
mutex_init(&fs_info->chunk_mutex);
mutex_init(&fs_info->transaction_kthread_mutex);
mutex_init(&fs_info->cleaner_mutex);
mutex_init(&fs_info->volume_mutex);
init_rwsem(&fs_info->extent_commit_sem);
init_rwsem(&fs_info->subvol_sem);
btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
init_waitqueue_head(&fs_info->transaction_throttle);
init_waitqueue_head(&fs_info->transaction_wait);
init_waitqueue_head(&fs_info->async_submit_wait);
__setup_root(4096, 4096, 4096, 4096, tree_root,
fs_info, BTRFS_ROOT_TREE_OBJECTID);
bh = btrfs_read_dev_super(fs_devices->latest_bdev);
if (!bh)
goto fail_iput;
memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
sizeof(fs_info->super_for_commit));
brelse(bh);
memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
disk_super = &fs_info->super_copy;
if (!btrfs_super_root(disk_super))
goto fail_iput;
ret = btrfs_parse_options(tree_root, options);
if (ret) {
err = ret;
goto fail_iput;
}
features = btrfs_super_incompat_flags(disk_super) &
~BTRFS_FEATURE_INCOMPAT_SUPP;
if (features) {
printk(KERN_ERR "BTRFS: couldn't mount because of "
"unsupported optional features (%Lx).\n",
(unsigned long long)features);
err = -EINVAL;
goto fail_iput;
}
features = btrfs_super_incompat_flags(disk_super);
if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
btrfs_set_super_incompat_flags(disk_super, features);
}
features = btrfs_super_compat_ro_flags(disk_super) &
~BTRFS_FEATURE_COMPAT_RO_SUPP;
if (!(sb->s_flags & MS_RDONLY) && features) {
printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
"unsupported option features (%Lx).\n",
(unsigned long long)features);
err = -EINVAL;
goto fail_iput;
}
printk("thread pool is %d\n", fs_info->thread_pool_size);
/* * we need to start all the end_io workers up front because the
* queue work function gets called at interrupt time, and so it
* cannot dynamically grow.
*/
btrfs_init_workers(&fs_info->workers, "worker",
fs_info->thread_pool_size);
btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
fs_info->thread_pool_size);
btrfs_init_workers(&fs_info->submit_workers, "submit",
min_t(u64, fs_devices->num_devices,
fs_info->thread_pool_size));
/* a higher idle thresh on the submit workers makes it much more
* likely that bios will be send down in a sane order to the
* devices
*/
fs_info->submit_workers.idle_thresh = 64;
fs_info->workers.idle_thresh = 16;
fs_info->workers.ordered = 1;
fs_info->delalloc_workers.idle_thresh = 2;
fs_info->delalloc_workers.ordered = 1;
btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
btrfs_init_workers(&fs_info->endio_workers, "endio",
fs_info->thread_pool_size);
btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
fs_info->thread_pool_size);
btrfs_init_workers(&fs_info->endio_meta_write_workers,
"endio-meta-write", fs_info->thread_pool_size);
btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
fs_info->thread_pool_size);
/*
* endios are largely parallel and should have a very
* low idle thresh
*/
fs_info->endio_workers.idle_thresh = 4;
fs_info->endio_meta_workers.idle_thresh = 4;
fs_info->endio_write_workers.idle_thresh = 2;
fs_info->endio_meta_write_workers.idle_thresh = 2;
fs_info->endio_workers.atomic_worker_start = 1;
fs_info->endio_meta_workers.atomic_worker_start = 1;
fs_info->endio_write_workers.atomic_worker_start = 1;
fs_info->endio_meta_write_workers.atomic_worker_start = 1;
btrfs_start_workers(&fs_info->workers, 1);
btrfs_start_workers(&fs_info->submit_workers, 1);
btrfs_start_workers(&fs_info->delalloc_workers, 1);
btrfs_start_workers(&fs_info->fixup_workers, 1);
btrfs_start_workers(&fs_info->endio_workers, 1);
btrfs_start_workers(&fs_info->endio_meta_workers, 1);
btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
btrfs_start_workers(&fs_info->endio_write_workers, 1);
fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
4 * 1024 * 1024 / PAGE_CACHE_SIZE);
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->s_blocksize = sectorsize;
sb->s_blocksize_bits = blksize_bits(sectorsize);
if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->magic))) {
printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
goto fail_sb_buffer;
}
mutex_lock(&fs_info->chunk_mutex);
ret = btrfs_read_sys_array(tree_root);
mutex_unlock(&fs_info->chunk_mutex);
if (ret) {
printk(KERN_WARNING "btrfs: failed to read the system "
"array on %s\n", sb->s_id);
goto fail_sb_buffer;
}
blocksize = btrfs_level_size(tree_root,
btrfs_super_chunk_root_level(disk_super));
generation = btrfs_super_chunk_root_generation(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, generation);
BUG_ON(!chunk_root->node);
if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
sb->s_id);
goto fail_chunk_root;
}
btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
chunk_root->commit_root = btrfs_root_node(chunk_root);
read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
(unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
BTRFS_UUID_SIZE);
mutex_lock(&fs_info->chunk_mutex);
ret = btrfs_read_chunk_tree(chunk_root);
mutex_unlock(&fs_info->chunk_mutex);
if (ret) {
printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
sb->s_id);
goto fail_chunk_root;
}
btrfs_close_extra_devices(fs_devices);
blocksize = btrfs_level_size(tree_root,
btrfs_super_root_level(disk_super));
generation = btrfs_super_generation(disk_super);
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super),
blocksize, generation);
if (!tree_root->node)
goto fail_chunk_root;
if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
sb->s_id);
goto fail_tree_root;
}
btrfs_set_root_node(&tree_root->root_item, tree_root->node); tree_root->commit_root = btrfs_root_node(tree_root);
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);
if (ret)
goto fail_extent_root;
dev_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_CSUM_TREE_OBJECTID, csum_root);
if (ret)
goto fail_dev_root;
csum_root->track_dirty = 1;
btrfs_read_block_groups(extent_root);
fs_info->generation = generation;
fs_info->last_trans_committed = generation;
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
"btrfs-cleaner");
if (IS_ERR(fs_info->cleaner_kthread))
goto fail_csum_root;
fs_info->transaction_kthread = kthread_run(transaction_kthread,
tree_root,
"btrfs-transaction");
if (IS_ERR(fs_info->transaction_kthread))
goto fail_cleaner;
if (!btrfs_test_opt(tree_root, SSD) &&
!btrfs_test_opt(tree_root, NOSSD) &&
!fs_info->fs_devices->rotating) {
printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
"mode\n");
btrfs_set_opt(fs_info->mount_opt, SSD);
}
if (btrfs_super_log_root(disk_super) != 0) {
u64 bytenr = btrfs_super_log_root(disk_super);
if (fs_devices->rw_devices == 0) {
printk(KERN_WARNING "Btrfs log replay required "
"on RO media\n");
err = -EIO;
goto fail_trans_kthread;
}
blocksize =
btrfs_level_size(tree_root,
btrfs_super_log_root_level(disk_super));
log_tree_root = kzalloc(sizeof(struct btrfs_root),
GFP_NOFS);
__setup_root(nodesize, leafsize, sectorsize, stripesize,
log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
log_tree_root->node = read_tree_block(tree_root, bytenr,
blocksize,
generation + 1);
ret = btrfs_recover_log_trees(log_tree_root); BUG_ON(ret);
if (sb->s_flags & MS_RDONLY) {
ret = btrfs_commit_super(tree_root);
BUG_ON(ret);
}
}
ret = btrfs_find_orphan_roots(tree_root);
BUG_ON(ret);
if (!(sb->s_flags & MS_RDONLY)) {
ret = btrfs_recover_relocation(tree_root);
BUG_ON(ret);
}
location.objectid = BTRFS_FS_TREE_OBJECTID;
location.type = BTRFS_ROOT_ITEM_KEY;
location.offset = (u64)-1;
fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
if (!fs_info->fs_root)
goto fail_trans_kthread;
return tree_root;
fail_trans_kthread:
kthread_stop(fs_info->transaction_kthread);
fail_cleaner:
kthread_stop(fs_info->cleaner_kthread);
/*
* make sure we're done with the btree inode before we stop our
* kthreads
*/
filemap_write_and_wait(fs_info->btree_inode->i_mapping);
invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
fail_csum_root:
free_extent_buffer(csum_root->node);
free_extent_buffer(csum_root->commit_root);
fail_dev_root:
free_extent_buffer(dev_root->node);
free_extent_buffer(dev_root->commit_root);
fail_extent_root:
free_extent_buffer(extent_root->node);
free_extent_buffer(extent_root->commit_root);
fail_tree_root:
free_extent_buffer(tree_root->node);
free_extent_buffer(tree_root->commit_root);
fail_chunk_root:
free_extent_buffer(chunk_root->node);
free_extent_buffer(chunk_root->commit_root);
fail_sb_buffer:
btrfs_stop_workers(&fs_info->fixup_workers);
btrfs_stop_workers(&fs_info->delalloc_workers);
btrfs_stop_workers(&fs_info->workers);
btrfs_stop_workers(&fs_info->endio_workers);
btrfs_stop_workers(&fs_info->endio_meta_workers);
btrfs_stop_workers(&fs_info->endio_meta_write_workers);
btrfs_stop_workers(&fs_info->endio_write_workers);
btrfs_stop_workers(&fs_info->submit_workers);
fail_iput:
invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
iput(fs_info->btree_inode);
btrfs_close_devices(fs_info->fs_devices);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
fail_bdi:
bdi_destroy(&fs_info->bdi);fail_srcu:
cleanup_srcu_struct(&fs_info->subvol_srcu);
fail:
kfree(extent_root);
kfree(tree_root);
kfree(fs_info);
kfree(chunk_root);
kfree(dev_root);
kfree(csum_root);
return ERR_PTR(err);
}
static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
{
char b[BDEVNAME_SIZE];
if (uptodate) {
set_buffer_uptodate(bh);
} else {
if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
bdevname(bh->b_bdev, b));
}
/* note, we dont' set_buffer_write_io_error because we have
* our own ways of dealing with the IO errors
*/
clear_buffer_uptodate(bh);
}
unlock_buffer(bh);
put_bh(bh);
}
struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
{
struct buffer_head *bh;
struct buffer_head *latest = NULL;
struct btrfs_super_block *super;
int i;
u64 transid = 0;
u64 bytenr;
/* we would like to check all the supers, but that would make
* a btrfs mount succeed after a mkfs from a different FS.
* So, we need to add a special mount option to scan for
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
for (i = 0; i < 1; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
break;
bh = __bread(bdev, bytenr / 4096, 4096);
if (!bh)
continue;
super = (struct btrfs_super_block *)bh->b_data;
if (btrfs_super_bytenr(super) != bytenr ||
strncmp((char *)(&super->magic), BTRFS_MAGIC,
sizeof(super->magic))) {
brelse(bh);
continue;
}
if (!latest || btrfs_super_generation(super) > transid) {
brelse(latest);
latest = bh;
transid = btrfs_super_generation(super);
} else {
brelse(bh);
} }
return latest;
}
/*
* this should be called twice, once with wait == 0 and
* once with wait == 1. When wait == 0 is done, all the buffer heads
* we write are pinned.
*
* They are released when wait == 1 is done.
* max_mirrors must be the same for both runs, and it indicates how
* many supers on this one device should be written.
*
* max_mirrors == 0 means to write them all.
*/
static int write_dev_supers(struct btrfs_device *device,
struct btrfs_super_block *sb,
int do_barriers, int wait, int max_mirrors)
{
struct buffer_head *bh;
int i;
int ret;
int errors = 0;
u32 crc;
u64 bytenr;
int last_barrier = 0;
if (max_mirrors == 0)
max_mirrors = BTRFS_SUPER_MIRROR_MAX;
/* make sure only the last submit_bh does a barrier */
if (do_barriers) {
for (i = 0; i < max_mirrors; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >=
device->total_bytes)
break;
last_barrier = i;
}
}
for (i = 0; i < max_mirrors; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
break;
if (wait) {
bh = __find_get_block(device->bdev, bytenr / 4096,
BTRFS_SUPER_INFO_SIZE);
BUG_ON(!bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
errors++;
/* drop our reference */
brelse(bh);
/* drop the reference from the wait == 0 run */
brelse(bh);
continue;
} else {
btrfs_set_super_bytenr(sb, bytenr);
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb +
BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE -
BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, sb->csum);
/*
* one reference for us, and we leave it for the
* caller
*/
bh = __getblk(device->bdev, bytenr / 4096,
BTRFS_SUPER_INFO_SIZE);
memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
/* one reference for submit_bh */
get_bh(bh);
set_buffer_uptodate(bh);
lock_buffer(bh);
bh->b_end_io = btrfs_end_buffer_write_sync;
}
if (i == last_barrier && do_barriers && device->barriers) {
ret = submit_bh(WRITE_BARRIER, bh);
if (ret == -EOPNOTSUPP) {
printk("btrfs: disabling barriers on dev %s\n",
device->name);
set_buffer_uptodate(bh);
device->barriers = 0;
/* one reference for submit_bh */
get_bh(bh);
lock_buffer(bh);
ret = submit_bh(WRITE_SYNC, bh);
}
} else {
ret = submit_bh(WRITE_SYNC, bh);
}
if (ret)
errors++;
}
return errors < i ? 0 : -1;
}
int write_all_supers(struct btrfs_root *root, int max_mirrors)
{
struct list_head *head;
struct btrfs_device *dev;
struct btrfs_super_block *sb;
struct btrfs_dev_item *dev_item;
int ret;
int do_barriers;
int max_errors;
int total_errors = 0;
u64 flags;
max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
do_barriers = !btrfs_test_opt(root, NOBARRIER);
sb = &root->fs_info->super_for_commit;
dev_item = &sb->dev_item;
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
head = &root->fs_info->fs_devices->devices;
list_for_each_entry(dev, head, dev_list) {
if (!dev->bdev) {
total_errors++;
continue;
}
if (!dev->in_fs_metadata || !dev->writeable)
continue;
btrfs_set_stack_device_generation(dev_item, 0);
btrfs_set_stack_device_type(dev_item, dev->type);
btrfs_set_stack_device_id(dev_item, dev->devid);
btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes); btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
btrfs_set_stack_device_io_align(dev_item, dev->io_align);
btrfs_set_stack_device_io_width(dev_item, dev->io_width);
btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
flags = btrfs_super_flags(sb);
btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
if (ret)
total_errors++;
}
if (total_errors > max_errors) {
printk(KERN_ERR "btrfs: %d errors while writing supers\n",
total_errors);
BUG();
}
total_errors = 0;
list_for_each_entry(dev, head, dev_list) {
if (!dev->bdev)
continue;
if (!dev->in_fs_metadata || !dev->writeable)
continue;
ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
if (ret)
total_errors++;
}
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
if (total_errors > max_errors) {
printk(KERN_ERR "btrfs: %d errors while writing supers\n",
total_errors);
BUG();
}
return 0;
}
int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root, int max_mirrors)
{
int ret;
ret = write_all_supers(root, max_mirrors);
return ret;
}
int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
{
spin_lock(&fs_info->fs_roots_radix_lock);
radix_tree_delete(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid);
spin_unlock(&fs_info->fs_roots_radix_lock);
if (btrfs_root_refs(&root->root_item) == 0)
synchronize_srcu(&fs_info->subvol_srcu);
free_fs_root(root);
return 0;
}
static void free_fs_root(struct btrfs_root *root)
{
WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
if (root->anon_super.s_dev) {
down_write(&root->anon_super.s_umount);
kill_anon_super(&root->anon_super);
} free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
kfree(root->name);
kfree(root);
}
static int del_fs_roots(struct btrfs_fs_info *fs_info)
{
int ret;
struct btrfs_root *gang[8];
int i;
while (!list_empty(&fs_info->dead_roots)) {
gang[0] = list_entry(fs_info->dead_roots.next,
struct btrfs_root, root_list);
list_del(&gang[0]->root_list);
if (gang[0]->in_radix) {
btrfs_free_fs_root(fs_info, gang[0]);
} else {
free_extent_buffer(gang[0]->node);
free_extent_buffer(gang[0]->commit_root);
kfree(gang[0]);
}
}
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 btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
{
u64 root_objectid = 0;
struct btrfs_root *gang[8];
int i;
int ret;
while (1) {
ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
(void **)gang, root_objectid,
ARRAY_SIZE(gang));
if (!ret)
break;
root_objectid = gang[ret - 1]->root_key.objectid + 1;
for (i = 0; i < ret; i++) {
root_objectid = gang[i]->root_key.objectid;
btrfs_orphan_cleanup(gang[i]);
}
root_objectid++;
}
return 0;
}
int btrfs_commit_super(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
int ret;
mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex); trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
BUG_ON(ret);
/* 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);
ret = write_ctree_super(NULL, root, 0);
return ret;
}
int close_ctree(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
fs_info->closing = 1;
smp_mb();
kthread_stop(root->fs_info->transaction_kthread);
kthread_stop(root->fs_info->cleaner_kthread);
if (!(fs_info->sb->s_flags & MS_RDONLY)) {
ret = btrfs_commit_super(root);
if (ret)
printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
}
fs_info->closing = 2;
smp_mb();
if (fs_info->delalloc_bytes) {
printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
(unsigned long long)fs_info->delalloc_bytes);
}
if (fs_info->total_ref_cache_size) {
printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
(unsigned long long)fs_info->total_ref_cache_size);
}
free_extent_buffer(fs_info->extent_root->node);
free_extent_buffer(fs_info->extent_root->commit_root);
free_extent_buffer(fs_info->tree_root->node);
free_extent_buffer(fs_info->tree_root->commit_root);
free_extent_buffer(root->fs_info->chunk_root->node);
free_extent_buffer(root->fs_info->chunk_root->commit_root);
free_extent_buffer(root->fs_info->dev_root->node);
free_extent_buffer(root->fs_info->dev_root->commit_root);
free_extent_buffer(root->fs_info->csum_root->node);
free_extent_buffer(root->fs_info->csum_root->commit_root);
btrfs_free_block_groups(root->fs_info);
del_fs_roots(fs_info);
iput(fs_info->btree_inode);
btrfs_stop_workers(&fs_info->fixup_workers);
btrfs_stop_workers(&fs_info->delalloc_workers);
btrfs_stop_workers(&fs_info->workers);
btrfs_stop_workers(&fs_info->endio_workers);
btrfs_stop_workers(&fs_info->endio_meta_workers);
btrfs_stop_workers(&fs_info->endio_meta_write_workers);
btrfs_stop_workers(&fs_info->endio_write_workers);
btrfs_stop_workers(&fs_info->submit_workers);
btrfs_close_devices(fs_info->fs_devices);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
bdi_destroy(&fs_info->bdi);
cleanup_srcu_struct(&fs_info->subvol_srcu);
kfree(fs_info->extent_root);
kfree(fs_info->tree_root);
kfree(fs_info->chunk_root);
kfree(fs_info->dev_root);
kfree(fs_info->csum_root);
return 0;
}
int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
{
int ret;
struct inode *btree_inode = buf->first_page->mapping->host;
ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
if (!ret)
return ret;
ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
parent_transid);
return !ret;
}
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;
int was_dirty;
btrfs_assert_tree_locked(buf);
if (transid != root->fs_info->generation) {
printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
"found %llu running %llu\n",
(unsigned long long)buf->start,
(unsigned long long)transid,
(unsigned long long)root->fs_info->generation);
WARN_ON(1);
}
was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
buf);
if (!was_dirty) {
spin_lock(&root->fs_info->delalloc_lock);
root->fs_info->dirty_metadata_bytes += buf->len;
spin_unlock(&root->fs_info->delalloc_lock);
}
}
void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
{
/*
* looks as though older kernels can get into trouble with
* this code, they end up stuck in balance_dirty_pages forever
*/
u64 num_dirty;
unsigned long thresh = 32 * 1024 * 1024;
if (current->flags & PF_MEMALLOC)
return;
num_dirty = root->fs_info->dirty_metadata_bytes;
if (num_dirty > thresh) {
balance_dirty_pages_ratelimited_nr(
root->fs_info->btree_inode->i_mapping, 1);
}
return;
}
int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
int ret;
ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
if (ret == 0)
set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
return ret;
}
int btree_lock_page_hook(struct page *page)
{
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_buffer *eb;
unsigned long len;
u64 bytenr = page_offset(page);
if (page->private == EXTENT_PAGE_PRIVATE)
goto out;
len = page->private >> 2;
eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
if (!eb)
goto out;
btrfs_tree_lock(eb);
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
spin_lock(&root->fs_info->delalloc_lock);
if (root->fs_info->dirty_metadata_bytes >= eb->len)
root->fs_info->dirty_metadata_bytes -= eb->len;
else
WARN_ON(1);
spin_unlock(&root->fs_info->delalloc_lock);
}
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
out:
lock_page(page);
return 0;
}
static struct extent_io_ops btree_extent_io_ops = {
.write_cache_pages_lock_hook = btree_lock_page_hook,
.readpage_end_io_hook = btree_readpage_end_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,
};