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Commit a0af469b authored by Chris Mason's avatar Chris Mason
Browse files

Fix btrfs_open_devices to deal with changes since the scan ioctls 



Devices can change after the scan ioctls are done, and btrfs_open_devices
needs to be able to verify them as they are opened and used by the FS.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent dfe25020

fs/btrfs/disk-io.c

+2 −2
Original line number Diff line number Diff line
@@ -1266,10 +1266,10 @@ struct btrfs_root *open_ctree(struct super_block *sb, 


	btrfs_parse_options(options, tree_root, NULL);



	if (btrfs_super_num_devices(disk_super) > fs_devices->num_devices) {

	if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {

		printk("Btrfs: wanted %llu devices, but found %llu\n",

		       (unsigned long long)btrfs_super_num_devices(disk_super),

		       (unsigned long long)fs_devices->num_devices);

		       (unsigned long long)fs_devices->open_devices);

		if (btrfs_test_opt(tree_root, DEGRADED))

			printk("continuing in degraded mode\n");

		else {

fs/btrfs/volumes.c

+59 −11
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ int btrfs_cleanup_fs_uuids(void) 
					 dev_list);

			if (dev->bdev) {

				close_bdev_excl(dev->bdev);

				fs_devices->open_devices--;

			}

			list_del(&dev->dev_list);

			kfree(dev->name);
@@ -174,9 +175,10 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) 
	list_for_each(cur, head) {

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

		if (!device->in_fs_metadata) {

printk("getting rid of extra dev %s\n", device->name);

			if (device->bdev)

			if (device->bdev) {

				close_bdev_excl(device->bdev);

				fs_devices->open_devices--;

			}

			list_del(&device->dev_list);

			list_del(&device->dev_alloc_list);

			fs_devices->num_devices--;
@@ -188,6 +190,7 @@ printk("getting rid of extra dev %s\n", device->name); 
	mutex_unlock(&uuid_mutex);

	return 0;

}



int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)

{

	struct list_head *head = &fs_devices->devices;
@@ -199,10 +202,12 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) 
		device = list_entry(cur, struct btrfs_device, dev_list);

		if (device->bdev) {

			close_bdev_excl(device->bdev);

			fs_devices->open_devices--;

		}

		device->bdev = NULL;

		device->in_fs_metadata = 0;

	}

	fs_devices->mounted = 0;

	mutex_unlock(&uuid_mutex);

	return 0;

}
@@ -214,9 +219,19 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 
	struct list_head *head = &fs_devices->devices;

	struct list_head *cur;

	struct btrfs_device *device;

	int ret;

	struct block_device *latest_bdev = NULL;

	struct buffer_head *bh;

	struct btrfs_super_block *disk_super;

	u64 latest_devid = 0;

	u64 latest_transid = 0;

	u64 transid;

	u64 devid;

	int ret = 0;



	mutex_lock(&uuid_mutex);

	if (fs_devices->mounted)

		goto out;



	list_for_each(cur, head) {

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

		if (device->bdev)
@@ -229,21 +244,52 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 


		if (IS_ERR(bdev)) {

			printk("open %s failed\n", device->name);

			ret = PTR_ERR(bdev);

			goto fail;

			goto error;

		}

		set_blocksize(bdev, 4096);

		if (device->devid == fs_devices->latest_devid)

			fs_devices->latest_bdev = bdev;



		bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);

		if (!bh)

			goto error_close;



		disk_super = (struct btrfs_super_block *)bh->b_data;

		if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,

		    sizeof(disk_super->magic)))

			goto error_brelse;



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

		if (devid != device->devid)

			goto error_brelse;



		transid = btrfs_super_generation(disk_super);

		if (transid > latest_transid) {

			latest_devid = devid;

			latest_transid = transid;

			latest_bdev = bdev;

		}



		device->bdev = bdev;

		device->in_fs_metadata = 0;

		fs_devices->open_devices++;

		continue;



error_brelse:

		brelse(bh);

error_close:

		close_bdev_excl(bdev);

error:

		continue;

	}

	if (fs_devices->open_devices == 0) {

		ret = -EIO;

		goto out;

	}

	fs_devices->mounted = 1;

	fs_devices->latest_bdev = latest_bdev;

	fs_devices->latest_devid = latest_devid;

	fs_devices->latest_trans = latest_transid;

out:

	mutex_unlock(&uuid_mutex);

	return 0;

fail:

	mutex_unlock(&uuid_mutex);

	btrfs_close_devices(fs_devices);

	return ret;

}
@@ -828,6 +874,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 
	if (device->bdev) {

		/* one close for the device struct or super_block */

		close_bdev_excl(device->bdev);

		root->fs_info->fs_devices->open_devices--;

	}

	if (bdev) {

		/* one close for us */
@@ -914,6 +961,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) 
	list_add(&device->dev_alloc_list,

		 &root->fs_info->fs_devices->alloc_list);

	root->fs_info->fs_devices->num_devices++;

	root->fs_info->fs_devices->open_devices++;

out:

	btrfs_end_transaction(trans, root);

	mutex_unlock(&root->fs_info->fs_mutex);

fs/btrfs/volumes.h

+2 −2
Original line number Diff line number Diff line
@@ -71,16 +71,16 @@ struct btrfs_fs_devices { 
	/* the device with this id has the most recent coyp of the super */

	u64 latest_devid;

	u64 latest_trans;

	u64 lowest_devid;

	u64 num_devices;

	u64 open_devices;

	struct block_device *latest_bdev;

	struct block_device *lowest_bdev;

	/* all of the devices in the FS */

	struct list_head devices;



	/* devices not currently being allocated */

	struct list_head alloc_list;

	struct list_head list;

	int mounted;

};



struct btrfs_bio_stripe {