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Commit 788f20eb authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Add new ioctl to add devices 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 8e7bf94f

fs/btrfs/ctree.h

+2 −0
Original line number Diff line number Diff line
@@ -551,6 +551,8 @@ struct btrfs_fs_info { 
	u64 data_alloc_profile;

	u64 metadata_alloc_profile;

	u64 system_alloc_profile;



	void *bdev_holder;

};



/*

fs/btrfs/inode.c

+23 −0
Original line number Diff line number Diff line
@@ -3070,6 +3070,27 @@ static int btrfs_ioctl_defrag(struct file *file) 
	return 0;

}



long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)

{

	struct btrfs_ioctl_vol_args *vol_args;

	int ret;



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



	if (!vol_args)

		return -ENOMEM;



	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {

		ret = -EFAULT;

		goto out;

	}

	ret = btrfs_init_new_device(root, vol_args->name);



out:

	kfree(vol_args);

	return ret;

}



long btrfs_ioctl(struct file *file, unsigned int

		cmd, unsigned long arg)

{
@@ -3082,6 +3103,8 @@ long btrfs_ioctl(struct file *file, unsigned int 
		return btrfs_ioctl_defrag(file);

	case BTRFS_IOC_RESIZE:

		return btrfs_ioctl_resize(root, (void __user *)arg);

	case BTRFS_IOC_ADD_DEV:

		return btrfs_ioctl_add_dev(root, (void __user *)arg);

	}



	return -ENOTTY;

fs/btrfs/ioctl.h

+6 −0
Original line number Diff line number Diff line
@@ -36,4 +36,10 @@ struct btrfs_ioctl_vol_args { 
				   struct btrfs_ioctl_vol_args)

#define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \

				   struct btrfs_ioctl_vol_args)

#define BTRFS_IOC_ADD_DEV _IOW(BTRFS_IOCTL_MAGIC, 10, \

				   struct btrfs_ioctl_vol_args)

#define BTRFS_IOC_RM_DEV _IOW(BTRFS_IOCTL_MAGIC, 11, \

				   struct btrfs_ioctl_vol_args)

#define BTRFS_IOC_BALANCE _IOW(BTRFS_IOCTL_MAGIC, 12, \

				   struct btrfs_ioctl_vol_args)

#endif

fs/btrfs/super.c

+1 −0
Original line number Diff line number Diff line
@@ -388,6 +388,7 @@ int btrfs_get_sb_bdev(struct file_system_type *fs_type, 
			goto error;

		}



		btrfs_sb(s)->fs_info->bdev_holder = fs_type;

		s->s_flags |= MS_ACTIVE;

	}

fs/btrfs/volumes.c

+75 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/bio.h>

#include <linux/buffer_head.h>

#include <linux/blkdev.h>

#include <linux/random.h>

#include <asm/div64.h>

#include "ctree.h"

#include "extent_map.h"
@@ -592,6 +593,80 @@ int btrfs_add_device(struct btrfs_trans_handle *trans, 
	return ret;

}



int btrfs_init_new_device(struct btrfs_root *root, char *device_path)

{

	struct btrfs_trans_handle *trans;

	struct btrfs_device *device;

	struct block_device *bdev;

	struct list_head *cur;

	struct list_head *devices;

	u64 total_bytes;

	int ret = 0;





	bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);

	if (!bdev) {

		return -EIO;

	}

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

	trans = btrfs_start_transaction(root, 1);

	devices = &root->fs_info->fs_devices->devices;

	list_for_each(cur, devices) {

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

		if (device->bdev == bdev) {

			ret = -EEXIST;

			goto out;

		}

	}



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

	if (!device) {

		/* we can safely leave the fs_devices entry around */

		ret = -ENOMEM;

		goto out_close_bdev;

	}



	device->barriers = 1;

	generate_random_uuid(device->uuid);

	spin_lock_init(&device->io_lock);

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

	if (!device->name) {

		kfree(device);

		goto out_close_bdev;

	}

	device->io_width = root->sectorsize;

	device->io_align = root->sectorsize;

	device->sector_size = root->sectorsize;

	device->total_bytes = i_size_read(bdev->bd_inode);

	device->dev_root = root->fs_info->dev_root;

	device->bdev = bdev;



	ret = btrfs_add_device(trans, root, device);

	if (ret)

		goto out_close_bdev;



	total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);

	btrfs_set_super_total_bytes(&root->fs_info->super_copy,

				    total_bytes + device->total_bytes);



	total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);

	btrfs_set_super_num_devices(&root->fs_info->super_copy,

				    total_bytes + 1);



	list_add(&device->dev_list, &root->fs_info->fs_devices->devices);

	list_add(&device->dev_alloc_list,

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

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

out:

	btrfs_end_transaction(trans, root);

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

	return ret;



out_close_bdev:

	close_bdev_excl(bdev);

	goto out;

}



int btrfs_update_device(struct btrfs_trans_handle *trans,

			struct btrfs_device *device)

{