![Chris Mason](/assets/img/avatar_default.png)
Before setting an extent to delalloc, the code needs to wait for pending ordered extents. Also, the relocation code needs to wait for ordered IO before scanning the block group again. This is because the extents are not removed until the IO for the new extents is finished Signed-off-by: Chris Mason <chris.mason@oracle.com>
700 lines
19 KiB
C
700 lines
19 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/gfp.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/writeback.h>
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#include <linux/pagevec.h>
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#include "ctree.h"
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#include "transaction.h"
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#include "btrfs_inode.h"
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#include "extent_io.h"
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static u64 entry_end(struct btrfs_ordered_extent *entry)
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{
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if (entry->file_offset + entry->len < entry->file_offset)
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return (u64)-1;
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return entry->file_offset + entry->len;
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}
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static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
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struct rb_node *node)
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{
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struct rb_node ** p = &root->rb_node;
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struct rb_node * parent = NULL;
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struct btrfs_ordered_extent *entry;
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while(*p) {
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parent = *p;
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entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
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if (file_offset < entry->file_offset)
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p = &(*p)->rb_left;
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else if (file_offset >= entry_end(entry))
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p = &(*p)->rb_right;
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else
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return parent;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
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struct rb_node **prev_ret)
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{
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struct rb_node * n = root->rb_node;
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struct rb_node *prev = NULL;
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struct rb_node *test;
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struct btrfs_ordered_extent *entry;
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struct btrfs_ordered_extent *prev_entry = NULL;
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while(n) {
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entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
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prev = n;
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prev_entry = entry;
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if (file_offset < entry->file_offset)
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n = n->rb_left;
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else if (file_offset >= entry_end(entry))
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n = n->rb_right;
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else
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return n;
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}
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if (!prev_ret)
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return NULL;
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while(prev && file_offset >= entry_end(prev_entry)) {
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test = rb_next(prev);
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if (!test)
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break;
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prev_entry = rb_entry(test, struct btrfs_ordered_extent,
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rb_node);
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if (file_offset < entry_end(prev_entry))
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break;
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prev = test;
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}
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if (prev)
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prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
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rb_node);
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while(prev && file_offset < entry_end(prev_entry)) {
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test = rb_prev(prev);
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if (!test)
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break;
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prev_entry = rb_entry(test, struct btrfs_ordered_extent,
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rb_node);
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prev = test;
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}
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*prev_ret = prev;
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return NULL;
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}
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static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
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{
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if (file_offset < entry->file_offset ||
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entry->file_offset + entry->len <= file_offset)
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return 0;
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return 1;
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}
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static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
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u64 file_offset)
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{
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struct rb_root *root = &tree->tree;
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struct rb_node *prev;
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struct rb_node *ret;
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struct btrfs_ordered_extent *entry;
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if (tree->last) {
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entry = rb_entry(tree->last, struct btrfs_ordered_extent,
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rb_node);
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if (offset_in_entry(entry, file_offset))
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return tree->last;
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}
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ret = __tree_search(root, file_offset, &prev);
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if (!ret)
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ret = prev;
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if (ret)
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tree->last = ret;
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return ret;
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}
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/* allocate and add a new ordered_extent into the per-inode tree.
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* file_offset is the logical offset in the file
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*
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* start is the disk block number of an extent already reserved in the
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* extent allocation tree
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*
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* len is the length of the extent
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*
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* This also sets the EXTENT_ORDERED bit on the range in the inode.
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*
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* The tree is given a single reference on the ordered extent that was
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* inserted.
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*/
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int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
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u64 start, u64 len)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry;
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tree = &BTRFS_I(inode)->ordered_tree;
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entry = kzalloc(sizeof(*entry), GFP_NOFS);
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if (!entry)
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return -ENOMEM;
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mutex_lock(&tree->mutex);
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entry->file_offset = file_offset;
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entry->start = start;
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entry->len = len;
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entry->inode = inode;
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/* one ref for the tree */
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atomic_set(&entry->refs, 1);
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init_waitqueue_head(&entry->wait);
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INIT_LIST_HEAD(&entry->list);
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INIT_LIST_HEAD(&entry->root_extent_list);
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node = tree_insert(&tree->tree, file_offset,
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&entry->rb_node);
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if (node) {
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printk("warning dup entry from add_ordered_extent\n");
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BUG();
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}
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set_extent_ordered(&BTRFS_I(inode)->io_tree, file_offset,
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entry_end(entry) - 1, GFP_NOFS);
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spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
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list_add_tail(&entry->root_extent_list,
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&BTRFS_I(inode)->root->fs_info->ordered_extents);
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spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
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mutex_unlock(&tree->mutex);
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BUG_ON(node);
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return 0;
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}
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/*
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* Add a struct btrfs_ordered_sum into the list of checksums to be inserted
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* when an ordered extent is finished. If the list covers more than one
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* ordered extent, it is split across multiples.
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*/
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int btrfs_add_ordered_sum(struct inode *inode,
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struct btrfs_ordered_extent *entry,
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struct btrfs_ordered_sum *sum)
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{
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struct btrfs_ordered_inode_tree *tree;
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tree = &BTRFS_I(inode)->ordered_tree;
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mutex_lock(&tree->mutex);
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list_add_tail(&sum->list, &entry->list);
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mutex_unlock(&tree->mutex);
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return 0;
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}
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/*
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* this is used to account for finished IO across a given range
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* of the file. The IO should not span ordered extents. If
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* a given ordered_extent is completely done, 1 is returned, otherwise
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* 0.
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*
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* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
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* to make sure this function only returns 1 once for a given ordered extent.
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*/
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int btrfs_dec_test_ordered_pending(struct inode *inode,
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u64 file_offset, u64 io_size)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry;
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struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
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int ret;
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tree = &BTRFS_I(inode)->ordered_tree;
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mutex_lock(&tree->mutex);
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clear_extent_ordered(io_tree, file_offset, file_offset + io_size - 1,
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GFP_NOFS);
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node = tree_search(tree, file_offset);
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if (!node) {
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ret = 1;
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goto out;
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}
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entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
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if (!offset_in_entry(entry, file_offset)) {
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ret = 1;
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goto out;
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}
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ret = test_range_bit(io_tree, entry->file_offset,
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entry->file_offset + entry->len - 1,
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EXTENT_ORDERED, 0);
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if (ret == 0)
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ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
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out:
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mutex_unlock(&tree->mutex);
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return ret == 0;
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}
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/*
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* used to drop a reference on an ordered extent. This will free
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* the extent if the last reference is dropped
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*/
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int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
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{
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struct list_head *cur;
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struct btrfs_ordered_sum *sum;
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if (atomic_dec_and_test(&entry->refs)) {
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while(!list_empty(&entry->list)) {
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cur = entry->list.next;
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sum = list_entry(cur, struct btrfs_ordered_sum, list);
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list_del(&sum->list);
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kfree(sum);
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}
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kfree(entry);
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}
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return 0;
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}
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/*
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* remove an ordered extent from the tree. No references are dropped
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* but, anyone waiting on this extent is woken up.
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*/
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int btrfs_remove_ordered_extent(struct inode *inode,
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struct btrfs_ordered_extent *entry)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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tree = &BTRFS_I(inode)->ordered_tree;
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mutex_lock(&tree->mutex);
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node = &entry->rb_node;
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rb_erase(node, &tree->tree);
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tree->last = NULL;
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set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
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spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
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list_del_init(&entry->root_extent_list);
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spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
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mutex_unlock(&tree->mutex);
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wake_up(&entry->wait);
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return 0;
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}
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int btrfs_wait_ordered_extents(struct btrfs_root *root)
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{
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struct list_head splice;
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struct list_head *cur;
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struct btrfs_ordered_extent *ordered;
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struct inode *inode;
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INIT_LIST_HEAD(&splice);
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spin_lock(&root->fs_info->ordered_extent_lock);
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list_splice_init(&root->fs_info->ordered_extents, &splice);
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while(!list_empty(&splice)) {
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cur = splice.next;
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ordered = list_entry(cur, struct btrfs_ordered_extent,
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root_extent_list);
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list_del_init(&ordered->root_extent_list);
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atomic_inc(&ordered->refs);
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inode = ordered->inode;
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/*
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* the inode can't go away until all the pages are gone
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* and the pages won't go away while there is still
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* an ordered extent and the ordered extent won't go
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* away until it is off this list. So, we can safely
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* increment i_count here and call iput later
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*/
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atomic_inc(&inode->i_count);
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spin_unlock(&root->fs_info->ordered_extent_lock);
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btrfs_start_ordered_extent(inode, ordered, 1);
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btrfs_put_ordered_extent(ordered);
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iput(inode);
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spin_lock(&root->fs_info->ordered_extent_lock);
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}
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spin_unlock(&root->fs_info->ordered_extent_lock);
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return 0;
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}
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/*
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* Used to start IO or wait for a given ordered extent to finish.
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*
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* If wait is one, this effectively waits on page writeback for all the pages
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* in the extent, and it waits on the io completion code to insert
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* metadata into the btree corresponding to the extent
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*/
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void btrfs_start_ordered_extent(struct inode *inode,
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struct btrfs_ordered_extent *entry,
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int wait)
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{
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u64 start = entry->file_offset;
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u64 end = start + entry->len - 1;
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/*
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* pages in the range can be dirty, clean or writeback. We
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* start IO on any dirty ones so the wait doesn't stall waiting
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* for pdflush to find them
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*/
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btrfs_fdatawrite_range(inode->i_mapping, start, end, WB_SYNC_NONE);
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if (wait)
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wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
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&entry->flags));
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}
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/*
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* Used to wait on ordered extents across a large range of bytes.
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*/
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void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
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{
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u64 end;
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u64 orig_end;
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u64 wait_end;
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struct btrfs_ordered_extent *ordered;
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if (start + len < start) {
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orig_end = INT_LIMIT(loff_t);
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} else {
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orig_end = start + len - 1;
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if (orig_end > INT_LIMIT(loff_t))
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orig_end = INT_LIMIT(loff_t);
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}
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wait_end = orig_end;
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again:
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/* start IO across the range first to instantiate any delalloc
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* extents
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*/
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btrfs_fdatawrite_range(inode->i_mapping, start, orig_end, WB_SYNC_NONE);
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btrfs_wait_on_page_writeback_range(inode->i_mapping,
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start >> PAGE_CACHE_SHIFT,
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orig_end >> PAGE_CACHE_SHIFT);
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end = orig_end;
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while(1) {
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ordered = btrfs_lookup_first_ordered_extent(inode, end);
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if (!ordered) {
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break;
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}
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if (ordered->file_offset > orig_end) {
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btrfs_put_ordered_extent(ordered);
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break;
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}
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if (ordered->file_offset + ordered->len < start) {
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btrfs_put_ordered_extent(ordered);
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break;
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}
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btrfs_start_ordered_extent(inode, ordered, 1);
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end = ordered->file_offset;
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btrfs_put_ordered_extent(ordered);
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if (end == 0 || end == start)
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break;
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end--;
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}
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if (test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
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EXTENT_ORDERED | EXTENT_DELALLOC, 0)) {
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printk("inode %lu still ordered or delalloc after wait "
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"%llu %llu\n", inode->i_ino,
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(unsigned long long)start,
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(unsigned long long)orig_end);
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goto again;
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}
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}
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/*
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* find an ordered extent corresponding to file_offset. return NULL if
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* nothing is found, otherwise take a reference on the extent and return it
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*/
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struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
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u64 file_offset)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry = NULL;
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tree = &BTRFS_I(inode)->ordered_tree;
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mutex_lock(&tree->mutex);
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node = tree_search(tree, file_offset);
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if (!node)
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goto out;
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entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
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if (!offset_in_entry(entry, file_offset))
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entry = NULL;
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if (entry)
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atomic_inc(&entry->refs);
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out:
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mutex_unlock(&tree->mutex);
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return entry;
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}
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/*
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* lookup and return any extent before 'file_offset'. NULL is returned
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* if none is found
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*/
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struct btrfs_ordered_extent *
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btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset)
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{
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struct btrfs_ordered_inode_tree *tree;
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struct rb_node *node;
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struct btrfs_ordered_extent *entry = NULL;
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tree = &BTRFS_I(inode)->ordered_tree;
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mutex_lock(&tree->mutex);
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node = tree_search(tree, file_offset);
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if (!node)
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goto out;
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entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
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atomic_inc(&entry->refs);
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out:
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mutex_unlock(&tree->mutex);
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return entry;
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}
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/*
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* After an extent is done, call this to conditionally update the on disk
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* i_size. i_size is updated to cover any fully written part of the file.
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*/
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int btrfs_ordered_update_i_size(struct inode *inode,
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struct btrfs_ordered_extent *ordered)
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{
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struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
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struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
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u64 disk_i_size;
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u64 new_i_size;
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u64 i_size_test;
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struct rb_node *node;
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struct btrfs_ordered_extent *test;
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mutex_lock(&tree->mutex);
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disk_i_size = BTRFS_I(inode)->disk_i_size;
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/*
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* if the disk i_size is already at the inode->i_size, or
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* this ordered extent is inside the disk i_size, we're done
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*/
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if (disk_i_size >= inode->i_size ||
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ordered->file_offset + ordered->len <= disk_i_size) {
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goto out;
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}
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/*
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* we can't update the disk_isize if there are delalloc bytes
|
|
* between disk_i_size and this ordered extent
|
|
*/
|
|
if (test_range_bit(io_tree, disk_i_size,
|
|
ordered->file_offset + ordered->len - 1,
|
|
EXTENT_DELALLOC, 0)) {
|
|
goto out;
|
|
}
|
|
/*
|
|
* walk backward from this ordered extent to disk_i_size.
|
|
* if we find an ordered extent then we can't update disk i_size
|
|
* yet
|
|
*/
|
|
node = &ordered->rb_node;
|
|
while(1) {
|
|
node = rb_prev(node);
|
|
if (!node)
|
|
break;
|
|
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
if (test->file_offset + test->len <= disk_i_size)
|
|
break;
|
|
if (test->file_offset >= inode->i_size)
|
|
break;
|
|
if (test->file_offset >= disk_i_size)
|
|
goto out;
|
|
}
|
|
new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode));
|
|
|
|
/*
|
|
* at this point, we know we can safely update i_size to at least
|
|
* the offset from this ordered extent. But, we need to
|
|
* walk forward and see if ios from higher up in the file have
|
|
* finished.
|
|
*/
|
|
node = rb_next(&ordered->rb_node);
|
|
i_size_test = 0;
|
|
if (node) {
|
|
/*
|
|
* do we have an area where IO might have finished
|
|
* between our ordered extent and the next one.
|
|
*/
|
|
test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
|
|
if (test->file_offset > entry_end(ordered)) {
|
|
i_size_test = test->file_offset - 1;
|
|
}
|
|
} else {
|
|
i_size_test = i_size_read(inode);
|
|
}
|
|
|
|
/*
|
|
* i_size_test is the end of a region after this ordered
|
|
* extent where there are no ordered extents. As long as there
|
|
* are no delalloc bytes in this area, it is safe to update
|
|
* disk_i_size to the end of the region.
|
|
*/
|
|
if (i_size_test > entry_end(ordered) &&
|
|
!test_range_bit(io_tree, entry_end(ordered), i_size_test,
|
|
EXTENT_DELALLOC, 0)) {
|
|
new_i_size = min_t(u64, i_size_test, i_size_read(inode));
|
|
}
|
|
BTRFS_I(inode)->disk_i_size = new_i_size;
|
|
out:
|
|
mutex_unlock(&tree->mutex);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* search the ordered extents for one corresponding to 'offset' and
|
|
* try to find a checksum. This is used because we allow pages to
|
|
* be reclaimed before their checksum is actually put into the btree
|
|
*/
|
|
int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
|
|
{
|
|
struct btrfs_ordered_sum *ordered_sum;
|
|
struct btrfs_sector_sum *sector_sums;
|
|
struct btrfs_ordered_extent *ordered;
|
|
struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
|
|
struct list_head *cur;
|
|
unsigned long num_sectors;
|
|
unsigned long i;
|
|
u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
|
|
int ret = 1;
|
|
|
|
ordered = btrfs_lookup_ordered_extent(inode, offset);
|
|
if (!ordered)
|
|
return 1;
|
|
|
|
mutex_lock(&tree->mutex);
|
|
list_for_each_prev(cur, &ordered->list) {
|
|
ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list);
|
|
if (offset >= ordered_sum->file_offset) {
|
|
num_sectors = ordered_sum->len / sectorsize;
|
|
sector_sums = ordered_sum->sums;
|
|
for (i = 0; i < num_sectors; i++) {
|
|
if (sector_sums[i].offset == offset) {
|
|
*sum = sector_sums[i].sum;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
out:
|
|
mutex_unlock(&tree->mutex);
|
|
btrfs_put_ordered_extent(ordered);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* taken from mm/filemap.c because it isn't exported
|
|
*
|
|
* __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
|
|
* @mapping: address space structure to write
|
|
* @start: offset in bytes where the range starts
|
|
* @end: offset in bytes where the range ends (inclusive)
|
|
* @sync_mode: enable synchronous operation
|
|
*
|
|
* Start writeback against all of a mapping's dirty pages that lie
|
|
* within the byte offsets <start, end> inclusive.
|
|
*
|
|
* If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
|
|
* opposed to a regular memory cleansing writeback. The difference between
|
|
* these two operations is that if a dirty page/buffer is encountered, it must
|
|
* be waited upon, and not just skipped over.
|
|
*/
|
|
int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
|
|
loff_t end, int sync_mode)
|
|
{
|
|
struct writeback_control wbc = {
|
|
.sync_mode = sync_mode,
|
|
.nr_to_write = mapping->nrpages * 2,
|
|
.range_start = start,
|
|
.range_end = end,
|
|
.for_writepages = 1,
|
|
};
|
|
return btrfs_writepages(mapping, &wbc);
|
|
}
|
|
|
|
/**
|
|
* taken from mm/filemap.c because it isn't exported
|
|
*
|
|
* wait_on_page_writeback_range - wait for writeback to complete
|
|
* @mapping: target address_space
|
|
* @start: beginning page index
|
|
* @end: ending page index
|
|
*
|
|
* Wait for writeback to complete against pages indexed by start->end
|
|
* inclusive
|
|
*/
|
|
int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
|
|
pgoff_t start, pgoff_t end)
|
|
{
|
|
struct pagevec pvec;
|
|
int nr_pages;
|
|
int ret = 0;
|
|
pgoff_t index;
|
|
|
|
if (end < start)
|
|
return 0;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
index = start;
|
|
while ((index <= end) &&
|
|
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
|
|
PAGECACHE_TAG_WRITEBACK,
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) {
|
|
unsigned i;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
/* until radix tree lookup accepts end_index */
|
|
if (page->index > end)
|
|
continue;
|
|
|
|
wait_on_page_writeback(page);
|
|
if (PageError(page))
|
|
ret = -EIO;
|
|
}
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
|
|
/* Check for outstanding write errors */
|
|
if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
|
|
ret = -ENOSPC;
|
|
if (test_and_clear_bit(AS_EIO, &mapping->flags))
|
|
ret = -EIO;
|
|
|
|
return ret;
|
|
}
|