Btrfs: A few updates for 2.6.18 and versions older than 2.6.25

This includes fixing a missing spinlock init call that caused oops on mount
for most kernels other than 2.6.25.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/disk-io.c

@@ -850,7 +850,9 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
 	bdi_init(bdi);
+#endif
 	bdi->ra_pages	= default_backing_dev_info.ra_pages * 4;
 	bdi->state		= 0;
 	bdi->capabilities	= default_backing_dev_info.capabilities;
@@ -950,7 +952,7 @@ void btrfs_end_io_csum(struct work_struct *work)
 		bio->bi_end_io = end_io_wq->end_io;
 		kfree(end_io_wq);
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-		bio_endio(bio, bio->bi_size, err);
+		bio_endio(bio, bio->bi_size, error);
 #else
 		bio_endio(bio, error);
 #endif
@@ -1037,10 +1039,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 			     fs_info->btree_inode->i_mapping, GFP_NOFS);
 	fs_info->do_barriers = 1;
 
-	INIT_WORK(&fs_info->end_io_work, btrfs_end_io_csum);
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
+	INIT_WORK(&fs_info->end_io_work, btrfs_end_io_csum, fs_info);
 	INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
 #else
+	INIT_WORK(&fs_info->end_io_work, btrfs_end_io_csum);
 	INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 #endif
 	BTRFS_I(fs_info->btree_inode)->root = tree_root;
@@ -1173,7 +1176,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	close_all_devices(fs_info);
 	kfree(extent_root);
 	kfree(tree_root);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
 	bdi_destroy(&fs_info->bdi);
+#endif
 	kfree(fs_info);
 	return ERR_PTR(err);
 }
@@ -1407,7 +1412,10 @@ int close_ctree(struct btrfs_root *root)
 #endif
 	close_all_devices(fs_info);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
 	bdi_destroy(&fs_info->bdi);
+#endif
 
 	kfree(fs_info->extent_root);
 	kfree(fs_info->tree_root);

fs/btrfs/file.c

@@ -908,11 +908,17 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 		if (err < 0)
 			num_written = err;
 	} else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+		do_sync_file_range(file, start_pos,
+				      start_pos + num_written - 1,
+				      SYNC_FILE_RANGE_WRITE |
+				      SYNC_FILE_RANGE_WAIT_AFTER);
+#else
 		do_sync_mapping_range(inode->i_mapping, start_pos,
 				      start_pos + num_written - 1,
 				      SYNC_FILE_RANGE_WRITE |
 				      SYNC_FILE_RANGE_WAIT_AFTER);
-
+#endif
 		invalidate_mapping_pages(inode->i_mapping,
 		      start_pos >> PAGE_CACHE_SHIFT,
 		     (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);

fs/btrfs/volumes.c

@@ -126,6 +126,7 @@ static int device_list_add(const char *path,
 		}
 		device->devid = devid;
 		device->barriers = 1;
+		spin_lock_init(&device->io_lock);
 		device->name = kstrdup(path, GFP_NOFS);
 		if (!device->name) {
 			kfree(device);
@@ -759,8 +760,8 @@ printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.objectid, c
 	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
 	spin_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em);
-	BUG_ON(ret);
 	spin_unlock(&em_tree->lock);
+	BUG_ON(ret);
 	free_extent_map(em);
 	return ret;
 }
@@ -799,6 +800,7 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
 
 	spin_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, logical, len);
+	spin_unlock(&em_tree->lock);
 	BUG_ON(!em);
 
 	BUG_ON(em->start > logical || em->start + em->len < logical);
@@ -808,7 +810,6 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
 	else
 		ret = 1;
 	free_extent_map(em);
-	spin_unlock(&em_tree->lock);
 	return ret;
 }
 
@@ -840,6 +841,7 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 
 	spin_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, logical, *length);
+	spin_unlock(&em_tree->lock);
 	BUG_ON(!em);
 
 	BUG_ON(em->start > logical || em->start + em->len < logical);
@@ -855,7 +857,6 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 	    ((map->type & BTRFS_BLOCK_GROUP_RAID1) ||
 	     (map->type & BTRFS_BLOCK_GROUP_DUP))) {
 		stripes_allocated = map->num_stripes;
-		spin_unlock(&em_tree->lock);
 		free_extent_map(em);
 		kfree(multi);
 		goto again;
@@ -932,7 +933,6 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 	*multi_ret = multi;
 out:
 	free_extent_map(em);
-	spin_unlock(&em_tree->lock);
 	return 0;
 }
 
@@ -1060,16 +1060,15 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 	length = key->offset;
 	spin_lock(&map_tree->map_tree.lock);
 	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
+	spin_unlock(&map_tree->map_tree.lock);
 
 	/* already mapped? */
 	if (em && em->start <= logical && em->start + em->len > logical) {
 		free_extent_map(em);
-		spin_unlock(&map_tree->map_tree.lock);
 		return 0;
 	} else if (em) {
 		free_extent_map(em);
 	}
-	spin_unlock(&map_tree->map_tree.lock);
 
 	map = kzalloc(sizeof(*map), GFP_NOFS);
 	if (!map)
@@ -1110,8 +1109,8 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 
 	spin_lock(&map_tree->map_tree.lock);
 	ret = add_extent_mapping(&map_tree->map_tree, em);
-	BUG_ON(ret);
 	spin_unlock(&map_tree->map_tree.lock);
+	BUG_ON(ret);
 	free_extent_map(em);
 
 	return 0;
@@ -1154,7 +1153,7 @@ static int read_one_dev(struct btrfs_root *root,
 			return -ENOMEM;
 		list_add(&device->dev_list,
 			 &root->fs_info->fs_devices->devices);
-		device->total_ios = 0;
+		device->barriers = 1;
 		spin_lock_init(&device->io_lock);
 	}