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Commit f2984462 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Write out all super blocks on commit, and bring back proper barrier support 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 16432985

fs/btrfs/disk-io.c

+113 −5
Original line number Diff line number Diff line
@@ -382,7 +382,7 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 
	BUG_ON(ret);



	if (offset == BTRFS_SUPER_INFO_OFFSET) {

		bio->bi_bdev = root->fs_info->sb->s_bdev;

		bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;

		submit_bio(rw, bio);

		return 0;

	}
@@ -988,7 +988,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	spin_lock_init(&fs_info->new_trans_lock);



	init_completion(&fs_info->kobj_unregister);

	sb_set_blocksize(sb, 4096);

	sb_set_blocksize(sb, BTRFS_SUPER_INFO_SIZE);

	fs_info->tree_root = tree_root;

	fs_info->extent_root = extent_root;

	fs_info->chunk_root = chunk_root;
@@ -1169,14 +1169,121 @@ fail: 
	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));

		}

		set_buffer_write_io_error(bh);

		clear_buffer_uptodate(bh);

	}

	unlock_buffer(bh);

	put_bh(bh);

}



int write_all_supers(struct btrfs_root *root)

{

	struct list_head *cur;

	struct list_head *head = &root->fs_info->fs_devices->devices;

	struct btrfs_device *dev;

	struct extent_buffer *sb;

	struct btrfs_dev_item *dev_item;

	struct buffer_head *bh;

	int ret;

	int do_barriers;



	do_barriers = !btrfs_test_opt(root, NOBARRIER);



	sb = root->fs_info->sb_buffer;

	dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,

						      dev_item);

	list_for_each(cur, head) {

		dev = list_entry(cur, struct btrfs_device, dev_list);

		btrfs_set_device_type(sb, dev_item, dev->type);

		btrfs_set_device_id(sb, dev_item, dev->devid);

		btrfs_set_device_total_bytes(sb, dev_item, dev->total_bytes);

		btrfs_set_device_bytes_used(sb, dev_item, dev->bytes_used);

		btrfs_set_device_io_align(sb, dev_item, dev->io_align);

		btrfs_set_device_io_width(sb, dev_item, dev->io_width);

		btrfs_set_device_sector_size(sb, dev_item, dev->sector_size);

		write_extent_buffer(sb, dev->uuid,

				    (unsigned long)btrfs_device_uuid(dev_item),

				    BTRFS_DEV_UUID_SIZE);



		btrfs_set_header_flag(sb, BTRFS_HEADER_FLAG_WRITTEN);

		csum_tree_block(root, sb, 0);



		bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET /

			      root->fs_info->sb->s_blocksize,

			      BTRFS_SUPER_INFO_SIZE);



		read_extent_buffer(sb, bh->b_data, 0, BTRFS_SUPER_INFO_SIZE);

		dev->pending_io = bh;



		get_bh(bh);

		set_buffer_uptodate(bh);

		lock_buffer(bh);

		bh->b_end_io = btrfs_end_buffer_write_sync;



		if (do_barriers && dev->barriers) {

			ret = submit_bh(WRITE_BARRIER, bh);

			if (ret == -EOPNOTSUPP) {

				printk("btrfs: disabling barriers on dev %s\n",

				       dev->name);

				set_buffer_uptodate(bh);

				dev->barriers = 0;

				get_bh(bh);

				lock_buffer(bh);

				ret = submit_bh(WRITE, bh);

			}

		} else {

			ret = submit_bh(WRITE, bh);

		}

		BUG_ON(ret);

	}



	list_for_each(cur, head) {

		dev = list_entry(cur, struct btrfs_device, dev_list);

		BUG_ON(!dev->pending_io);

		bh = dev->pending_io;

		wait_on_buffer(bh);

		if (!buffer_uptodate(dev->pending_io)) {

			if (do_barriers && dev->barriers) {

				printk("btrfs: disabling barriers on dev %s\n",

				       dev->name);

				set_buffer_uptodate(bh);

				get_bh(bh);

				lock_buffer(bh);

				dev->barriers = 0;

				ret = submit_bh(WRITE, bh);

				BUG_ON(ret);

				wait_on_buffer(bh);

				BUG_ON(!buffer_uptodate(bh));

			} else {

				BUG();

			}



		}

		dev->pending_io = NULL;

		brelse(bh);

	}

	return 0;

}



int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root

		      *root)

{

	int ret;

	struct extent_buffer *super = root->fs_info->sb_buffer;

	struct inode *btree_inode = root->fs_info->btree_inode;

	struct super_block *sb = root->fs_info->sb;



	ret = write_all_supers(root);

#if 0

	if (!btrfs_test_opt(root, NOBARRIER))

		blkdev_issue_flush(sb->s_bdev, NULL);

	set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
@@ -1184,6 +1291,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root 
				     super->start, super->len);

	if (!btrfs_test_opt(root, NOBARRIER))

		blkdev_issue_flush(sb->s_bdev, NULL);

#endif

	return ret;

}

fs/btrfs/disk-io.h

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#define __DISKIO__



#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)

#define BTRFS_SUPER_INFO_SIZE 4096

struct btrfs_device;

struct btrfs_fs_devices;

fs/btrfs/volumes.c

+5 −3
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ static int device_list_add(const char *path, 
			return -ENOMEM;

		}

		device->devid = devid;

		device->barriers = 1;

		device->name = kstrdup(path, GFP_NOFS);

		if (!device->name) {

			kfree(device);
@@ -208,6 +209,7 @@ int btrfs_scan_one_device(const char *path, int flags, void *holder, 
	struct buffer_head *bh;

	int ret;

	u64 devid;

	u64 transid;



	mutex_lock(&uuid_mutex);
@@ -236,14 +238,14 @@ int btrfs_scan_one_device(const char *path, int flags, void *holder, 
		goto error_brelse;

	}

	devid = le64_to_cpu(disk_super->dev_item.devid);

	printk("found device %Lu on %s\n", devid, path);

	transid = btrfs_super_generation(disk_super);

	printk("found device %Lu transid %Lu on %s\n", devid, transid, path);

	ret = device_list_add(path, disk_super, devid, fs_devices_ret);



error_brelse:

	brelse(bh);

error_close:

	close_bdev_excl(bdev);

	printk("scan one closes bdev %s\n", path);

error:

	mutex_unlock(&uuid_mutex);

	return ret;
@@ -1143,7 +1145,7 @@ static int read_one_dev(struct btrfs_root *root, 
	device = btrfs_find_device(root, devid);

	if (!device) {

		printk("warning devid %Lu not found already\n", devid);

		device = kmalloc(sizeof(*device), GFP_NOFS);

		device = kzalloc(sizeof(*device), GFP_NOFS);

		if (!device)

			return -ENOMEM;

		list_add(&device->dev_list,

fs/btrfs/volumes.h

+3 −0
Original line number Diff line number Diff line
@@ -21,9 +21,12 @@ 


#include <linux/bio.h>



struct buffer_head;

struct btrfs_device {

	struct list_head dev_list;

	struct btrfs_root *dev_root;

	struct buffer_head *pending_io;

	int barriers;

	spinlock_t io_lock;



	struct block_device *bdev;