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/* * Copyright (C) 2007 Oracle.  All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/slab.h>#include <linux/blkdev.h>#include <linux/writeback.h>#include <linux/pagevec.h>#include "ctree.h"#include "transaction.h"#include "btrfs_inode.h"#include "extent_io.h"#include "disk-io.h"#include "compression.h" static struct kmem_cache *btrfs_ordered_extent_cache; static u64 entry_end(struct btrfs_ordered_extent *entry){	if (entry->file_offset + entry->len < entry->file_offset)		return (u64)-1;	return entry->file_offset + entry->len;} /* returns NULL if the insertion worked, or it returns the node it did find * in the tree */static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,				   struct rb_node *node){	struct rb_node **p = &root->rb_node;	struct rb_node *parent = NULL;	struct btrfs_ordered_extent *entry; 	while (*p) {		parent = *p;		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node); 		if (file_offset < entry->file_offset)			p = &(*p)->rb_left;		else if (file_offset >= entry_end(entry))			p = &(*p)->rb_right;		else			return parent;	} 	rb_link_node(node, parent, p);	rb_insert_color(node, root);	return NULL;} static void ordered_data_tree_panic(struct inode *inode, int errno,					       u64 offset){	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);	btrfs_panic(fs_info, errno,		    "Inconsistency in ordered tree at offset %llu", offset);} /* * look for a given offset in the tree, and if it can't be found return the * first lesser offset */static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,				     struct rb_node **prev_ret){	struct rb_node *n = root->rb_node;	struct rb_node *prev = NULL;	struct rb_node *test;	struct btrfs_ordered_extent *entry;	struct btrfs_ordered_extent *prev_entry = NULL; 	while (n) {		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);		prev = n;		prev_entry = entry; 		if (file_offset < entry->file_offset)			n = n->rb_left;		else if (file_offset >= entry_end(entry))			n = n->rb_right;		else			return n;	}	if (!prev_ret)		return NULL; 	while (prev && file_offset >= entry_end(prev_entry)) {		test = rb_next(prev);		if (!test)			break;		prev_entry = rb_entry(test, struct btrfs_ordered_extent,				      rb_node);		if (file_offset < entry_end(prev_entry))			break; 		prev = test;	}	if (prev)		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,				      rb_node);	while (prev && file_offset < entry_end(prev_entry)) {		test = rb_prev(prev);		if (!test)			break;		prev_entry = rb_entry(test, struct btrfs_ordered_extent,				      rb_node);		prev = test;	}	*prev_ret = prev;	return NULL;} /* * helper to check if a given offset is inside a given entry */static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset){	if (file_offset < entry->file_offset ||	    entry->file_offset + entry->len <= file_offset)		return 0;	return 1;} static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,			  u64 len){	if (file_offset + len <= entry->file_offset ||	    entry->file_offset + entry->len <= file_offset)		return 0;	return 1;} /* * look find the first ordered struct that has this offset, otherwise * the first one less than this offset */static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,					  u64 file_offset){	struct rb_root *root = &tree->tree;	struct rb_node *prev = NULL;	struct rb_node *ret;	struct btrfs_ordered_extent *entry; 	if (tree->last) {		entry = rb_entry(tree->last, struct btrfs_ordered_extent,				 rb_node);		if (offset_in_entry(entry, file_offset))			return tree->last;	}	ret = __tree_search(root, file_offset, &prev);	if (!ret)		ret = prev;	if (ret)		tree->last = ret;	return ret;} /* allocate and add a new ordered_extent into the per-inode tree. * file_offset is the logical offset in the file * * start is the disk block number of an extent already reserved in the * extent allocation tree * * len is the length of the extent * * The tree is given a single reference on the ordered extent that was * inserted. */static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,				      u64 start, u64 len, u64 disk_len,				      int type, int dio, int compress_type){	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);	struct btrfs_root *root = BTRFS_I(inode)->root;	struct btrfs_ordered_inode_tree *tree;	struct rb_node *node;	struct btrfs_ordered_extent *entry; 	tree = &BTRFS_I(inode)->ordered_tree;	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);	if (!entry)		return -ENOMEM; 	entry->file_offset = file_offset;	entry->start = start;	entry->len = len;	entry->disk_len = disk_len;	entry->bytes_left = len;	entry->inode = igrab(inode);	entry->compress_type = compress_type;	entry->truncated_len = (u64)-1;	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)		set_bit(type, &entry->flags); 	if (dio)		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); 	/* one ref for the tree */	refcount_set(&entry->refs, 1);	init_waitqueue_head(&entry->wait);	INIT_LIST_HEAD(&entry->list);	INIT_LIST_HEAD(&entry->root_extent_list);	INIT_LIST_HEAD(&entry->work_list);	init_completion(&entry->completion);	INIT_LIST_HEAD(&entry->log_list);	INIT_LIST_HEAD(&entry->trans_list); 	trace_btrfs_ordered_extent_add(inode, entry); 	spin_lock_irq(&tree->lock);	node = tree_insert(&tree->tree, file_offset,			   &entry->rb_node);	if (node)		ordered_data_tree_panic(inode, -EEXIST, file_offset);	spin_unlock_irq(&tree->lock); 	spin_lock(&root->ordered_extent_lock);	list_add_tail(&entry->root_extent_list,		      &root->ordered_extents);	root->nr_ordered_extents++;	if (root->nr_ordered_extents == 1) {		spin_lock(&fs_info->ordered_root_lock);		BUG_ON(!list_empty(&root->ordered_root));		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);		spin_unlock(&fs_info->ordered_root_lock);	}	spin_unlock(&root->ordered_extent_lock); 	return 0;} int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,			     u64 start, u64 len, u64 disk_len, int type){	return __btrfs_add_ordered_extent(inode, file_offset, start, len,					  disk_len, type, 0,					  BTRFS_COMPRESS_NONE);} int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,				 u64 start, u64 len, u64 disk_len, int type){	return __btrfs_add_ordered_extent(inode, file_offset, start, len,					  disk_len, type, 1,					  BTRFS_COMPRESS_NONE);} int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,				      u64 start, u64 len, u64 disk_len,				      int type, int compress_type){	return __btrfs_add_ordered_extent(inode, file_offset, start, len,					  disk_len, type, 0,					  compress_type);} /* * Add a struct btrfs_ordered_sum into the list of checksums to be inserted * when an ordered extent is finished.  If the list covers more than one * ordered extent, it is split across multiples. */void btrfs_add_ordered_sum(struct inode *inode,			   struct btrfs_ordered_extent *entry,			   struct btrfs_ordered_sum *sum){	struct btrfs_ordered_inode_tree *tree; 	tree = &BTRFS_I(inode)->ordered_tree;	spin_lock_irq(&tree->lock);	list_add_tail(&sum->list, &entry->list);	spin_unlock_irq(&tree->lock);} /* * this is used to account for finished IO across a given range * of the file.  The IO may span ordered extents.  If * a given ordered_extent is completely done, 1 is returned, otherwise * 0. * * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used * to make sure this function only returns 1 once for a given ordered extent. * * file_offset is updated to one byte past the range that is recorded as * complete.  This allows you to walk forward in the file. */int btrfs_dec_test_first_ordered_pending(struct inode *inode,				   struct btrfs_ordered_extent **cached,				   u64 *file_offset, u64 io_size, int uptodate){	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);	struct btrfs_ordered_inode_tree *tree;	struct rb_node *node;	struct btrfs_ordered_extent *entry = NULL;	int ret;	unsigned long flags;	u64 dec_end;	u64 dec_start;	u64 to_dec; 	tree = &BTRFS_I(inode)->ordered_tree;	spin_lock_irqsave(&tree->lock, flags);	node = tree_search(tree, *file_offset);	if (!node) {		ret = 1;		goto out;	} 	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);	if (!offset_in_entry(entry, *file_offset)) {		ret = 1;		goto out;	} 	dec_start = max(*file_offset, entry->file_offset);	dec_end = min(*file_offset + io_size, entry->file_offset +		      entry->len);	*file_offset = dec_end;	if (dec_start > dec_end) {		btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",			   dec_start, dec_end);	}	to_dec = dec_end - dec_start;	if (to_dec > entry->bytes_left) {		btrfs_crit(fs_info,			   "bad ordered accounting left %llu size %llu",			   entry->bytes_left, to_dec);	}	entry->bytes_left -= to_dec;	if (!uptodate)		set_bit(BTRFS_ORDERED_IOERR, &entry->flags); 	if (entry->bytes_left == 0) {		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);		/*		 * Implicit memory barrier after test_and_set_bit		 */		if (waitqueue_active(&entry->wait))			wake_up(&entry->wait);	} else {		ret = 1;	}out:	if (!ret && cached && entry) {		*cached = entry;		refcount_inc(&entry->refs);	}	spin_unlock_irqrestore(&tree->lock, flags);	return ret == 0;} /* * this is used to account for finished IO across a given range * of the file.  The IO should not span ordered extents.  If * a given ordered_extent is completely done, 1 is returned, otherwise * 0. * * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used * to make sure this function only returns 1 once for a given ordered extent. */int btrfs_dec_test_ordered_pending(struct inode *inode,				   struct btrfs_ordered_extent **cached,				   u64 file_offset, u64 io_size, int uptodate){	struct btrfs_ordered_inode_tree *tree;	struct rb_node *node;	struct btrfs_ordered_extent *entry = NULL;	unsigned long flags;	int ret; 	tree = &BTRFS_I(inode)->ordered_tree;	spin_lock_irqsave(&tree->lock, flags);	if (cached && *cached) {		entry = *cached;		goto have_entry;	} 	node = tree_search(tree, file_offset);	if (!node) {		ret = 1;		goto out;	} 	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);have_entry:	if (!offset_in_entry(entry, file_offset)) {		ret = 1;		goto out;	} 	if (io_size > entry->bytes_left) {		btrfs_crit(BTRFS_I(inode)->root->fs_info,			   "bad ordered accounting left %llu size %llu",		       entry->bytes_left, io_size);	}	entry->bytes_left -= io_size;	if (!uptodate)		set_bit(BTRFS_ORDERED_IOERR, &entry->flags); 	if (entry->bytes_left == 0) {		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);		/*		 * Implicit memory barrier after test_and_set_bit		 */		if (waitqueue_active(&entry->wait))			wake_up(&entry->wait);	} else {		ret = 1;	}out:	if (!ret && cached && entry) {		*cached = entry;		refcount_inc(&entry->refs);	}	spin_unlock_irqrestore(&tree->lock, flags);	return ret == 0;} /* Needs to either be called under a log transaction or the log_mutex */void btrfs_get_logged_extents(struct btrfs_inode *inode,			      struct list_head *logged_list,			      const loff_t start,			      const loff_t end){	struct btrfs_ordered_inode_tree *tree;	struct btrfs_ordered_extent *ordered;	struct rb_node *n;	struct rb_node *prev; 	tree = &inode->ordered_tree;	spin_lock_irq(&tree->lock);	n = __tree_search(&tree->tree, end, &prev);	if (!n)		n = prev;	for (; n; n = rb_prev(n)) {		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);		if (ordered->file_offset > end)			continue;		if (entry_end(ordered) <= start)			break;		if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))			continue;		list_add(&ordered->log_list, logged_list);		refcount_inc(&ordered->refs);	}	spin_unlock_irq(&tree->lock);} void btrfs_put_logged_extents(struct list_head *logged_list){	struct btrfs_ordered_extent *ordered; 	while (!list_empty(logged_list)) {		ordered = list_first_entry(logged_list,					   struct btrfs_ordered_extent,					   log_list);		list_del_init(&ordered->log_list);		btrfs_put_ordered_extent(ordered);	}} void btrfs_submit_logged_extents(struct list_head *logged_list,				 struct btrfs_root *log){	int index = log->log_transid % 2; 	spin_lock_irq(&log->log_extents_lock[index]);	list_splice_tail(logged_list, &log->logged_list[index]);	spin_unlock_irq(&log->log_extents_lock[index]);} void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,			       struct btrfs_root *log, u64 transid){	struct btrfs_ordered_extent *ordered;	int index = transid % 2; 	spin_lock_irq(&log->log_extents_lock[index]);	while (!list_empty(&log->logged_list[index])) {		struct inode *inode;		ordered = list_first_entry(&log->logged_list[index],					   struct btrfs_ordered_extent,					   log_list);		list_del_init(&ordered->log_list);		inode = ordered->inode;

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